KR20200138145A - Composite sheet for forming support sheet and protective film - Google Patents

Abstract

This support sheet is provided with a substrate, a pressure-sensitive adhesive layer is provided on the substrate, and the pressure-sensitive adhesive layer side surface of the substrate is an uneven surface, and a test piece having a size of 3 mm x 3 mm is cut out from five places of the support sheet. When the minimum and maximum values of the thickness of the pressure-sensitive adhesive layer are obtained for each of the sheet test pieces, the average value of the minimum value is 1.5 µm or more, and the average value of the maximum value is 9 µm or less. The composite sheet for forming a protective film is provided with a film for forming a protective film on the pressure-sensitive adhesive layer in this supporting sheet.

Description

Composite sheet for forming support sheet and protective film

The present invention relates to a supporting sheet and a composite sheet for forming a protective film.

In recent years, semiconductor devices to which a mounting method called a so-called face down method is applied are being manufactured. In the face-down method, a semiconductor chip having electrodes such as bumps on a circuit surface is used, and the electrodes are bonded to the substrate. For this reason, the rear surface of the semiconductor chip opposite to the circuit surface may be exposed.

On the back surface of the exposed semiconductor chip, a resin film containing an organic material is formed as a protective film, and the protective film is sometimes introduced into a semiconductor device as a semiconductor chip. The protective film is used to prevent cracks from occurring in the semiconductor chip after the dicing process or packaging.

Such a protective film is formed, for example, by curing a film for forming a protective film having curability. In addition, a film for forming a non-curable protective film with controlled physical properties may be used as a protective film as it is. In addition, the film for forming a protective film is affixed to the back surface of a semiconductor wafer and used. The protective film-forming film may be affixed to the back surface of the semiconductor wafer in the form of a composite sheet for forming a protective film integrated with the support sheet used for processing the semiconductor wafer, for example, or the semiconductor wafer in a state that is not integrated with the support sheet. It is also attached to the back side of.

After the protective film-forming composite sheet is affixed to the back surface of the semiconductor chip by the protective film-forming film therein, the protective film is formed by curing the protective film-forming film at appropriate timing, the protective film-forming film or the protective film is cut, and the semiconductor Dividing the wafer into semiconductor chips (dicing), picking up a film for forming a protective film after cutting, or a semiconductor chip with a protective film on the back surface (a semiconductor chip with a film for forming a protective film or a semiconductor chip with a protective film) from a support sheet, etc. This is done appropriately. When the semiconductor chip on which the protective film-forming film is formed is picked up, this becomes a semiconductor chip on which the protective film is formed by curing the protective film-forming film, and finally, a semiconductor device is manufactured using the semiconductor chip on which the protective film is formed. Thus, the supporting sheet in the composite sheet for forming a protective film can be used as a dicing sheet. On the other hand, when the film for protective film formation is non-curable, the film for protective film formation in each of these steps is treated as a protective film as it is.

On the other hand, after the protective film-forming film is affixed on the back surface of the semiconductor wafer in a state that is not integrated with the support sheet, the support sheet is affixed to the exposed surface of the protective film-forming film on the opposite side to the affixed surface of the semiconductor wafer. . Thereafter, a semiconductor chip on which a protective film is formed or a semiconductor chip on which a protective film-forming film is formed is obtained in the same manner as in the case of using the composite sheet for forming a protective film, and a semiconductor device is manufactured. In this case, the film for forming a protective film is affixed on the back surface of the semiconductor wafer in a state that is not integrated with the support sheet, but the composite sheet for forming a protective film is formed by integration with the support sheet after the affixing.

As such a composite sheet for forming a protective film, for example, a dicing tape (support sheet) having a substrate having an uneven surface and an adhesive layer laminated on the uneven surface side of the substrate, and on the adhesive layer of the dicing tape A dicing tape-integrated semiconductor back surface protective film (composite sheet for forming a protective film) having a dicing tape-integrated semiconductor back surface protective film (film for forming a protective film) laminated on the dicing tape, wherein the dicing tape has a haze of 45% or less. A film is disclosed (refer to Patent Document 1).

However, in the composite sheet for forming a protective film disclosed in Patent Document 1 (a dicing tape-integrated semiconductor back surface protective film), the pressure-sensitive adhesive layer is laminated on the concave-convex-processed side of the substrate, so that the pressure-sensitive adhesive layer or this pressure-sensitive adhesive layer is laminated. In some cases, the effect of the above-described irregularities appears on the film for forming a protective film (film for protecting the semiconductor back surface). For example, when the surface on the side of the film for forming a protective film of the pressure-sensitive adhesive layer becomes a concave-convex surface, an area in which they are not bonded (non-bonded area) is formed between the pressure-sensitive adhesive layer and the film for protective film formation, and the lamination thereof is deteriorated. There is. In addition, printing may be performed on the side of the pressure-sensitive adhesive layer of the protective film or film for forming a protective film by laser irradiation, but the thickness of the pressure-sensitive adhesive layer becomes non-uniform, and in the area where the pressure-sensitive adhesive layer is thick, printing through the substrate and the pressure-sensitive adhesive layer The visibility of may decrease.

Japanese Patent No. 5432853

The present invention is a support sheet comprising a pressure-sensitive adhesive layer on the side of the uneven surface of a substrate, wherein in the composite sheet for forming a protective film comprising a film for forming a protective film on the pressure-sensitive adhesive layer, good lamination properties of the pressure-sensitive adhesive layer and the film for forming a protective film, An object of the present invention is to provide a support sheet capable of realizing good printing visibility via a support sheet for a protective film or a film for forming a protective film, and a composite sheet for forming a protective film provided with the support sheet.

The present invention is a support sheet comprising a substrate and a pressure-sensitive adhesive layer on the substrate, wherein the pressure-sensitive adhesive layer side surface of the substrate is an uneven surface, and a test piece is cut out from five places of the support sheet, In the above, when the minimum and maximum values of the thickness of the pressure-sensitive adhesive layers are calculated, a supporting sheet is provided in which the average value of the minimum value is 1.5 μm or more, and the average value of the maximum value is 9 μm or less.

In the support sheet of the present invention, the pressure-sensitive adhesive layer may directly contact the uneven surface of the substrate.

In addition, the present invention provides a protective film-forming composite sheet provided with a protective film-forming film on the pressure-sensitive adhesive layer in the support sheet.

By constituting the composite sheet for forming a protective film using the support sheet of the present invention, good lamination of the pressure-sensitive adhesive layer and the film for forming a protective film, and good print visibility through the support sheet for the protective film or film for forming a protective film can be realized.

1 is a cross-sectional view schematically showing a supporting sheet and a composite sheet for forming a protective film according to an embodiment of the present invention.
2 is a cross-sectional view schematically showing a composite sheet for forming a protective film according to an embodiment of the present invention together with a support sheet.
3 is a cross-sectional view schematically showing a composite sheet for forming a protective film according to an embodiment of the present invention together with a support sheet.
4 is an enlarged cross-sectional view of the supporting sheet and the composite sheet for forming a protective film shown in FIG. 1.

◇Composite sheet for supporting sheet and protective film formation

A support sheet according to an embodiment of the present invention is a support sheet having a substrate and a pressure-sensitive adhesive layer on the substrate, wherein the pressure-sensitive adhesive layer side surface of the substrate is an uneven surface, and a test piece is removed from five locations of the support sheet. When cutting out and obtaining the minimum and maximum values of the thickness of the pressure-sensitive adhesive layer in each of these five test pieces, the average value of the minimum values (in this specification, it may be referred to as "S value") becomes 1.5 μm or more, The average value (in this specification, it may be called "L value") of the said maximum value is 9 micrometers or less.

Further, the composite sheet for forming a protective film according to an embodiment of the present invention includes a film for forming a protective film on the pressure-sensitive adhesive layer in the support sheet.

The support sheet includes a pressure-sensitive adhesive layer on the uneven surface side of the base material, but in the composite sheet for forming a protective film comprising this support sheet, the influence of the uneven surface is suppressed.

More specifically, when the S value of the pressure-sensitive adhesive layer is 1.5 μm or more, the lamination property of the pressure-sensitive adhesive layer and the film for forming a protective film becomes good. In the present specification, "lamination" means the normality of the stacked state of two layers of interest, unless otherwise noted. "Good lamination" means, for example, that there is no non-bonding area (void) between two adjacent layers to be targeted, or that the number of non-bonded areas is small and the interlayer distance of the non-bonded area is small. do.

On the other hand, when the L value of the pressure-sensitive adhesive layer is 9 µm or less, the printing visibility through the supporting sheet of the protective film or film for forming a protective film becomes good.

The test piece was cut out from five locations of the support sheet, and was obtained by cutting the support sheet over the entire thickness direction. The test piece is a small piece with the entire layer constituting the support sheet.

The size of the test piece is not particularly limited, but the length of one side of the laminated or exposed surface of each layer (substrate, adhesive layer, etc.) constituting the test piece is preferably 2 mm or more. By using a test piece of this size, the S value and L value of the pressure-sensitive adhesive layer are more accurately determined.

The maximum value of the length of one side is not particularly limited. For example, it is preferable that the length of one side is 10 mm or less from the viewpoint of easier preparation of the test piece.

The planar shape of the test piece, that is, the shape of the laminated or exposed surface of each layer (substrate, pressure-sensitive adhesive layer, etc.) constituting the test piece is preferably a polygonal shape, and a square shape is preferable in that it is easier to cut the test piece. More preferable.

As a preferable test piece, for example, a laminated surface or an exposed surface of each layer (substrate, pressure-sensitive adhesive layer, etc.) constituting the test piece may have a square shape having a size of 3 mm×3 mm. However, this is an example of a preferred test piece.

The position at which the five specimens are cut out in the support sheet is not particularly limited, but may be selected in consideration of the position to be laminated of the film for forming a protective film to be described later so that the S value and L value of the pressure-sensitive adhesive layer can be more accurately determined. .

For example, one of the positions where the protective film-forming film is to be laminated in the support sheet, the center (weight center) of the protective film-forming film is to be disposed, and is a part near the periphery of the protective film-forming film, and About this center (center of weight) part, the position of a point object is roughly mentioned, 5 places of 4 places which are planned to arrange|position.

In the support sheet, the distance between the centers (centers of weight) of the cut-out positions of the test pieces is preferably 50 to 200 mm. By doing in this way, the S value and the L value of an adhesive layer can be calculated|required more precisely.

In order to obtain the S value and L value of the pressure-sensitive adhesive layer from the test piece, a cross section is newly formed in the test piece, and in this formed cross-section, the minimum and maximum values of the thickness of the pressure-sensitive adhesive layer are measured for each test piece.

The newly formed cross section may be only one surface per test piece, or may be two or more, but usually only one surface is sufficient.

And the S value and L value may be calculated from these at least five minimum and maximum values.

In the test piece, a cross section can be formed by a known method. For example, by using a known cross-section sample preparation device (cross section polisher), it is possible to form a cross section in a test piece with high reproducibility by suppressing deviation.

The minimum and maximum values of the thickness of the pressure-sensitive adhesive layer can be measured, for example, by observing the cross section of the test piece using a scanning electron microscope (SEM).

In the cross section of each test piece, the region for measuring the minimum and maximum values of the thickness of the pressure-sensitive adhesive layer is a direction perpendicular to the lamination direction of each layer (substrate, pressure-sensitive adhesive layer, etc.) constituting the test piece (approximately the laminated surface of each layer). Alternatively, it is preferably a region of 50 to 1500 µm in a direction parallel to the exposed surface). By doing in this way, it is possible to measure the minimum and maximum values of the thickness of the pressure-sensitive adhesive layer with high efficiency and high precision.

When the minimum value of the thickness of the pressure-sensitive adhesive layer is compared between the support sheet at the stage in which the composite sheet for forming a protective film is not formed and the support sheet constituting the composite sheet for forming a protective film, these minimum values are the same, or , The minimum value in the support sheet constituting the composite sheet for forming a protective film is a degree to be slightly smaller, and even when such a decrease is made, the difference is negligible.

The same applies to the maximum value of the thickness of the pressure-sensitive adhesive layer. That is, when comparing the maximum value of the thickness of the pressure-sensitive adhesive layer between the support sheet at the stage where the composite sheet for forming a protective film is not formed and the support sheet constituting the composite sheet for forming a protective film, these maximum values are mutually The same, or the above maximum value in the supporting sheet constituting the composite sheet for forming a protective film is a degree to be slightly smaller, and even when such a decrease is made, the difference is negligible.

Accordingly, the S value and L value of the pressure-sensitive adhesive layer may be obtained in the same manner as in the case of using the test piece cut out from the support sheet using a test piece cut out from the composite sheet for forming a protective film instead of the support sheet. When a test piece cut out from the composite sheet for forming a protective film is used as described above, when the S value of the pressure-sensitive adhesive layer is 1.5 μm or more and the L value of the pressure-sensitive adhesive layer is 9 μm or less, the composite sheet for forming a protective film is It is supposed to reflect the effects of the invention.

That is, the composite sheet for forming a protective film according to an embodiment of the present invention is a composite sheet for forming a protective film having a film for forming a protective film on the pressure-sensitive adhesive layer in the support sheet, and test pieces are taken from five locations of the composite sheet for forming a protective film. Cut out, and when the minimum and maximum values of the thickness of the pressure-sensitive adhesive layer in each of these five test pieces were determined, the average value (S value) of the minimum values became 1.5 μm or more, and the average value (L value) of the maximum values was 9 μm. It becomes below.

On the other hand, the test piece cut out from the composite sheet for forming a protective film is obtained by cutting the composite sheet for forming a protective film over the entire thickness direction, and is a small piece provided with the entire layer constituting the composite sheet for forming a protective film.

Hereinafter, the overall configuration of the composite sheet for forming a protective film of the present invention will be described with reference to the drawings. Meanwhile, in the drawings used in the following description, for convenience, in order to make it easier to understand the features of the present invention, the main part is sometimes enlarged and shown, and the dimensional ratio of each component is not limited to the same as in reality. Does not.

1 is a cross-sectional view schematically showing a supporting sheet and a composite sheet for forming a protective film according to an embodiment of the present invention.

The protective film-forming composite sheet 1A shown here includes a substrate 11, a pressure-sensitive adhesive layer 12 on the substrate 11, and a protective film-forming film 13 on the pressure-sensitive adhesive layer 12 It is equipped with. The support sheet 10 is a laminate of the substrate 11 and the pressure-sensitive adhesive layer 12, and the composite sheet 1A for forming a protective film is, in other words, one side of the support sheet 10 (in this specification, the It may be referred to as "one side") (10a) has a structure in which the film 13 for forming a protective film is laminated. Further, the protective film forming composite sheet 1A further includes a release film 15 on the protective film forming film 13.

In the composite sheet 1A for forming a protective film, a pressure-sensitive adhesive layer 12 is laminated on one side of the substrate 11 (in this specification, it may be referred to as a “first side”) 11a, and the pressure-sensitive adhesive layer A protective film-forming film 13 is laminated on the entire surface of 12a on the side opposite to the substrate 11 side in (12) (in this specification, it may be referred to as ``first surface''), and a protective film is formed. A jig adhesive layer on a part of the surface of the film 13 on the opposite side to the pressure-sensitive adhesive layer 12 side (in this specification, it may be referred to as a ``first surface'') 13a, that is, a region near the periphery (16) is laminated and, of the first surface 13a of the protective film forming film 13, the surface on which the jig adhesive layer 16 is not laminated, and the protective film forming film of the jig adhesive layer 16 The release film 15 is laminated on the surface 16a (upper surface and side surface) not in contact with (13).

In addition, in FIG. 1, reference numeral 13b denotes a surface on the side of the pressure-sensitive adhesive layer 12 of the film 13 for forming a protective film (in this specification, it may be referred to as a "second surface").

The jig adhesive layer 16 may have, for example, a single-layer structure containing an adhesive component, or a multilayer structure in which layers containing an adhesive component are laminated on both surfaces of a sheet serving as a core material.

In the composite sheet 1A for forming a protective film, the first surface 11a of the substrate 11 is an uneven surface.

Further, the pressure-sensitive adhesive layer 12 is formed in direct contact with the first surface (corrugated surface) 11a of the substrate 11. For this reason, the surface on the side of the substrate 11 of the pressure-sensitive adhesive layer 12 (in this specification, it may be referred to as a "second surface") 12b is an uneven surface.

In the protective film-forming composite sheet 1A, the side opposite to the side of the pressure-sensitive adhesive layer 12 of the substrate 11 (in this specification, it may be referred to as a ``second surface'') 11b is an uneven surface and Any of a smooth surface (non-corrugated surface and a glossy surface) may be used, but a smooth surface is preferable. The second surface 11b of the substrate 11 is a surface opposite to the protective film-forming film 13 side of the support sheet 10 (in this specification, it may be referred to as a ``second surface'') 10b ) Can also be said.

The "uneven surface" and the "smooth surface" will be described in detail later.

In the protective film-forming composite sheet 1A shown in FIG. 1, the back surface of a semiconductor wafer (not shown) is affixed to the first surface 13a of the protective film-forming film 13 with the release film 15 removed. Further, the upper surface of the surface 16a of the jig adhesive layer 16 is affixed to a jig such as a ring frame and used.

2 is a cross-sectional view schematically showing a composite sheet for forming a protective film according to another embodiment of the present invention together with a support sheet.

On the other hand, in the drawings after FIG. 2, the same reference numerals as those in the drawings described above are denoted by the same reference numerals as those in the drawings already described, and detailed descriptions thereof will be omitted.

The protective film-forming composite sheet 1B shown here is the same as the protective film-forming composite sheet 1A shown in FIG. 1 except that the jig adhesive layer 16 is not provided. That is, in the composite sheet 1B for forming a protective film, the pressure-sensitive adhesive layer 12 is laminated on the first surface 11a of the substrate 11, and the entire surface of the first surface 12a of the pressure-sensitive adhesive layer 12 The protective film-forming film 13 is laminated, and the release film 15 is laminated on the entire surface of the first surface 13a of the protective film-forming film 13.

Also in the composite sheet 1B for forming a protective film, the first surface 11a of the substrate 11 is an uneven surface.

Further, the pressure-sensitive adhesive layer 12 is formed in direct contact with the first surface (corrugated surface) 11a of the substrate 11. For this reason, the surface (2nd surface) 12b of the base material 11 side of the adhesive layer 12 is an uneven surface.

Also in the composite sheet 1B for forming a protective film, the second surface 11b of the base material 11 (that is, the second surface 10b of the support sheet 10) is among the uneven surface and the smooth surface (non-corrugated surface). Although any may be sufficient, it is preferable that it is a smooth surface.

The protective film-forming composite sheet 1B shown in FIG. 2 is a semiconductor wafer (shown in the figure) in a partial region on the center side of the first surface 13a of the protective film-forming film 13 with the release film 15 removed. The back surface of (omitted) is affixed, and a region near the periphery is affixed to a jig such as a ring frame and used.

3 is a cross-sectional view schematically showing a composite sheet for forming a protective film according to still another embodiment of the present invention together with a support sheet.

The protective film-forming composite sheet 1C shown here is the same as the protective film-forming composite sheet 1B shown in FIG. 2 except that the shape of the protective film-forming film is different. That is, the protective film-forming composite sheet 1C includes a substrate 11, a pressure-sensitive adhesive layer 12 on the substrate 11, and a protective film-forming film 23 on the pressure-sensitive adhesive layer 12. We have. The support sheet 10 is a laminate of the substrate 11 and the pressure-sensitive adhesive layer 12, and the protective film-forming composite sheet 1C is, in other words, the first surface of the support sheet 10 (the protective film-forming film 23 ) Side) has a configuration in which a protective film-forming film 23 is laminated on (10a). In addition, the protective film-forming composite sheet 1C is further provided with the release film 15 on the protective film-forming film 23.

In the composite sheet 1C for forming a protective film, the adhesive layer 12 is laminated on the first surface 11a of the substrate 11, and a part of the first surface 12a of the adhesive layer 12, that is, the center The protective film-forming film 23 is laminated on the side region. And, of the first surface 12a of the pressure-sensitive adhesive layer 12, a region in which the protective film-forming film 23 is not laminated and the surface not in contact with the pressure-sensitive adhesive layer 12 of the protective film-forming film 23 The release film 15 is laminated on (23a) (upper surface and side surface).

In addition, in FIG. 3, reference numeral 23b denotes a surface on the side of the pressure-sensitive adhesive layer 12 of the film 23 for forming a protective film (in this specification, it may be referred to as a "second surface").

When the protective film-forming composite sheet 1C is viewed from above and viewed in plan view, the protective film-forming film 23 has a smaller surface area than the pressure-sensitive adhesive layer 12, and has, for example, a shape such as a circle shape.

Also in the composite sheet 1C for forming a protective film, the first surface 11a of the substrate 11 is an uneven surface.

Further, the pressure-sensitive adhesive layer 12 is formed in direct contact with the first surface (corrugated surface) 11a of the substrate 11. For this reason, the surface (2nd surface) 12b of the base material 11 side of the adhesive layer 12 is an uneven surface.

In the composite sheet 1C for forming a protective film, the second surface 11b of the base material 11 (that is, the second surface 10b of the support sheet 10) is among the uneven surface and the smooth surface (non-corrugated surface). Although any may be sufficient, it is preferable that it is a smooth surface.

In the protective film-forming composite sheet 1C shown in FIG. 3, the back surface of a semiconductor wafer (not shown) is affixed to the surface 23a of the protective film-forming film 23 in the state in which the release film 15 is removed, Of the first surface 12a of the pressure-sensitive adhesive layer 12, a region in which the protective film-forming film 23 is not laminated is affixed to a jig such as a ring frame and used.

On the other hand, in the composite sheet 1C for forming a protective film shown in FIG. 3, in the region of the first surface 12a of the pressure-sensitive adhesive layer 12, in a region in which the protective film forming film 23 is not laminated, as shown in FIG. Similarly, the jig adhesive layer may be laminated (not shown). In the composite sheet 1C for forming a protective film having such a jig adhesive layer, the upper surface of the jig adhesive layer is affixed to a jig such as a ring frame in the same manner as the composite sheet for forming a protective film shown in FIG. 1 and used.

As described above, the composite sheet for forming a protective film may have any form of the supporting sheet and the film for forming a protective film or provided with an adhesive layer for a jig. However, usually, as shown in Fig. 1, as a composite sheet for forming a protective film having a jig adhesive layer, it is preferable that a jig adhesive layer is provided on a film for forming a protective film.

The composite sheet for forming a protective film according to an embodiment of the present invention is not limited to those shown in Figs. 1 to 3, and within a range that does not impair the effects of the present invention, some configurations of those shown in Figs. It may be changed or deleted, or another configuration may be added to the one described so far.

For example, in the composite sheet for forming a protective film shown in FIGS. 1 to 3, an intermediate layer may be formed between the substrate 11 and the pressure-sensitive adhesive layer 12. That is, in the composite sheet for forming a protective film of the present invention, the support sheet may be constituted by laminating a substrate, an intermediate layer, and an adhesive layer in this order in their thickness direction. Any intermediate layer may be selected according to the purpose.

In addition, in the composite sheet for forming a protective film shown in Figs. 1 to 3, layers other than the intermediate layer may be formed at arbitrary locations.

Further, in the composite sheet for forming a protective film, a partial gap may be formed between the release film and the layer in direct contact with the release film.

In addition, in the composite sheet for forming a protective film, the size and shape of each layer can be arbitrarily adjusted according to the purpose.

However, as shown in Figs. 1 to 3, in the composite sheet for forming a protective film, the pressure-sensitive adhesive layer is in direct contact with the uneven surface (first surface) of the substrate, that is, an intermediate layer is formed between the substrate and the pressure-sensitive adhesive layer. It is not provided, and it is preferable that the pressure-sensitive adhesive layer is directly contacted and laminated on the substrate.

In addition, in the protective film-forming composite sheet, the protective film-forming film is in direct contact with the first surface of the pressure-sensitive adhesive layer, that is, no other layer is provided between the pressure-sensitive adhesive layer and the protective film-forming film, and the pressure-sensitive adhesive layer It is preferable that the protective film-forming film is directly contacted and laminated thereon.

In addition, the protective film-forming composite sheet satisfies these conditions together, that is, the substrate, the pressure-sensitive adhesive layer, and the protective film-forming film are in direct contact with each other in the thickness direction in this order and are laminated to be formed. desirable.

It is preferable that the support sheet is transparent.

The supporting sheet may be colored depending on the purpose, or other layers may be deposited.

For example, when the film for forming a protective film is energy ray-curable, it is preferable that the supporting sheet transmit energy rays.

In the present specification, the term "energy ray" means having both energy among electromagnetic waves or charged particle rays, and examples thereof include ultraviolet rays, radiation, and electron rays. Ultraviolet rays can be irradiated by using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet source. The electron beam can be irradiated with what is generated by an electron beam accelerator or the like.

In the present specification, "energy ray curable" means a property that is hardened by irradiation with energy rays, and "non-energy ray curable" means a property that does not cure even when irradiated with energy rays.

In the support sheet, the transmittance of light having a wavelength of 375 nm is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. When the transmittance of the light is within such a range, when the film for forming a protective film is irradiated with energy rays (ultraviolet rays) through the support sheet, the degree of curing of the film for forming a protective film is further improved.

In the support sheet, the upper limit of the transmittance of light having a wavelength of 375 nm is not particularly limited. For example, the transmittance of the light may be 95% or less.

In the support sheet, the transmittance of light having a wavelength of 532 nm is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. When the transmittance of the light is within such a range, when a film for forming a protective film or a protective film is irradiated with laser light through a support sheet and printed on them, printing can be performed more clearly.

In the support sheet, the upper limit of the transmittance of light having a wavelength of 532 nm is not particularly limited. For example, the transmittance of the light may be 95% or less.

In the support sheet, the transmittance of light having a wavelength of 1064 nm is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. When the transmittance of the light is within such a range, when a film for forming a protective film or a protective film is irradiated with laser light through a support sheet and printed on them, printing can be performed more clearly.

In the support sheet, the upper limit of the transmittance of light having a wavelength of 1064 nm is not particularly limited. For example, the transmittance of the light may be 95% or less.

The transmission clarity of the supporting sheet is preferably 30 or more, more preferably 100 or more, and particularly preferably 200 or more. When the transmittance clarity is within this range, it becomes easier to confirm the lifting and peeling of the film for forming a protective film through the support sheet, problems of printing, and defects.

The transmission sharpness of the support sheet is not particularly limited. For example, the transmission sharpness may be 430 or less.

The transmission sharpness of the support sheet can be measured in accordance with JIS K 7374-2007.

Next, each layer constituting the supporting sheet and the composite sheet for forming a protective film will be described in detail.

○ Description

The substrate is in the form of a sheet or a film and has an uneven surface.

In this specification, the "uneven surface" means a surface having a maximum height roughness (Rz) of 0.01 µm or more specified in JIS B 0601:2013.

In addition, a "smooth surface" is not an uneven surface, but means a surface with high smoothness, and may be called a "non-corrugated surface" or a "glossy surface". For example, the smooth surface includes a surface having an extremely small unevenness degree that does not correspond to the uneven surface.

In the substrate, only one surface may be an uneven surface, and both surfaces may be both an uneven surface, but it is preferable that only one surface is an uneven surface. In other words, in the substrate, it is preferable that only one surface is a smooth surface. In the support sheet, the uneven surface of the base material becomes the surface on the side with the pressure-sensitive adhesive layer.

The substrate may be composed of one layer (single layer), may be composed of a plurality of layers of two or more layers, and when composed of a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited. Does not.

When the base material is made of a plurality of layers, the surface of the outermost layer (the surface closest to the adhesive layer, or both surfaces of the surface closest to and farthest to the adhesive layer) among the plurality of layers becomes the uneven surface.

In the present specification, it is not limited to the case of a description, and "the multiple layers may be the same or different from each other" means "all the layers may be the same, all layers may be different, and only some of the layers may be the same". Means, and "the multiple layers are different from each other" means that "at least one of the constituent materials and thicknesses of each layer are different from each other".

The maximum height roughness (Rz) measured in accordance with JIS B 0601:2013 on the uneven surface (first surface) on the side with the pressure-sensitive adhesive layer of the substrate is preferably 0.01 to 8 µm, and 0.1 to 7 µm. It is more preferable and it is especially preferable that it is 0.5-6 micrometers. When the Rz of the base material is equal to or greater than the lower limit, the occurrence of problems when the base material is individually wound up in a roll shape and unwound is suppressed. Further, in the manufacturing process of the supporting sheet or the composite sheet for forming a protective film, the occurrence of a problem when winding and unwinding similarly to a laminate including a substrate is suppressed. On the other hand, when the Rz of the base material is equal to or less than the above upper limit, both the lamination property of the pressure-sensitive adhesive layer and the film for forming a protective film, and the print visibility through the supporting sheet of the protective film or the film for forming a protective film become good.

When both surfaces of the substrate are uneven, the unevenness of both surfaces may be the same or different.

As a constituent material of the said base material, various resins are mentioned, for example.

Examples of the resin include polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE); Polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene and norbornene resin; Ethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer (copolymer obtained using ethylene as a monomer) ; Vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer (resins obtained using vinyl chloride as a monomer); polystyrene; Polycycloolefin; Polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and wholly aromatic polyesters in which all structural units have aromatic cyclic groups; A copolymer of two or more of the above polyesters; Poly(meth)acrylic acid ester; Polyurethane; Polyurethane acrylate; Polyimide; Polyamide; Polycarbonate; Fluororesin; Polyacetal; Modified polyphenylene oxide; Polyphenylene sulfide; Polysulfone; Polyether ketone, etc. are mentioned.

Further, examples of the resin include polymer alloys such as a mixture of the polyester and other resins. It is preferable that the polymer alloy of the polyester and other resins has a relatively small amount of resin other than polyester.

In addition, as the resin, for example, a crosslinked resin obtained by crosslinking one or two or more of the resins exemplified so far; Modified resins such as ionomers using one or two or more of the resins exemplified so far can also be mentioned.

In this specification, "(meth)acrylic acid" is a concept including both "acrylic acid" and "methacrylic acid". The same applies to terms similar to (meth)acrylic acid, for example, "(meth)acryloyl group" is a concept including both "acryloyl group" and "methacryloyl group", and "(meth) "Acrylate" is a concept including both "acrylate" and "methacrylate".

The number of resins constituting the substrate may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The thickness of the substrate is preferably in the range of 50 to 300 µm, and more preferably in the range of 60 to 150 µm. When the thickness of the substrate is within this range, the flexibility of the composite sheet for forming a protective film and the adhesion to the semiconductor wafer or semiconductor chip are further improved.

Since the substrate has an uneven surface as described above, the thickness thereof fluctuates depending on the portion of the substrate. Accordingly, the minimum value of the thickness of the substrate may be equal to or greater than the lower limit, and the maximum value of the thickness of the substrate may be equal to or less than the upper limit.

On the other hand, "thickness of a base material" means the thickness of the whole base material, and, for example, the thickness of a base material which consists of multiple layers means the total thickness of all the layers which comprise a base material.

The thickness of the substrate can be measured by observing the side or cross section of the substrate using, for example, a scanning electron microscope (SEM).

The cross-section of the base material can be formed by the same method as in the case of the cross-section in the test piece of the support sheet and the composite sheet for forming a protective film, for example.

For example, by cutting out a test piece from a plurality of locations (e.g., 5 locations) of a supporting sheet or a composite sheet for forming a protective film by the method described above, the minimum and maximum values of the thickness of the substrate in the test piece are obtained, and these In addition, when the average value of these minimum values and the average values of the maximum values are obtained from the value of, the average value of the minimum value may be equal to or greater than the lower limit of the thickness of the substrate described above, and the average value of the maximum value may be equal to or less than the upper limit of the thickness of the substrate described above. .

The base material may contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, softeners (plasticizers), in addition to the main constituent materials such as the resin.

It is preferable that the substrate is transparent.

The substrate may be colored depending on the purpose, or other layers may be deposited.

For example, when the film for forming a protective film is energy ray-curable, it is preferable that the substrate transmits energy rays.

The substrate is oxidized by corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone/ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment, etc. in order to improve the adhesion with the layer in direct contact such as the pressure-sensitive adhesive layer formed thereon. Treatment or the like may be applied to the surface.

In addition, the substrate may have a surface subjected to a primer treatment.

In addition, the substrate is an antistatic coating layer; When the composite sheet for forming a protective film is stacked and stored, the substrate may be adhered to another sheet, or may have a layer that prevents the substrate from adhering to the adsorption table.

The substrate can be manufactured by a known method. For example, a base material containing a resin can be produced by molding a resin composition containing the resin.

When using a base material that does not have an uneven surface (that is, a base material whose both sides are smooth surfaces), the smooth surface of the base material may be subjected to an uneven treatment.

The uneven treatment can be performed by a known method. For example, by using a metal roll or a metal plate having an uneven surface and pressing the uneven surface against the smooth surface of the base material, the smooth surface of the base material can be subjected to an uneven treatment. At this time, it is preferable to press the heated metal roll or metal plate to the smooth surface of the substrate. Further, the smooth surface of the substrate can be subjected to an uneven treatment by sand blast treatment or solvent treatment.

○Adhesive layer

The pressure-sensitive adhesive layer is in the form of a sheet or a film.

In the pressure-sensitive adhesive layer, usually, regardless of the presence or absence of an intermediate layer between the base material and the pressure-sensitive adhesive layer, the uneven surface of the base material is affected, and at least the surface of the base material is an uneven surface.

The pressure-sensitive adhesive layer may consist of one layer (single layer), may consist of a plurality of layers of two or more layers, and in the case of a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is specifically limited. It doesn't work.

When the pressure-sensitive adhesive layer is formed of a plurality of layers, the surface of the outermost layer (the surface closest to the base material) among the plurality of layers becomes the uneven surface.

Here, the base material and the pressure-sensitive adhesive layer will be described in more detail with reference to the drawings.

4 is an enlarged cross-sectional view schematically showing a composite sheet for forming a protective film according to an embodiment of the present invention. Here, the composite sheet 1A for forming a protective film shown in Fig. 1 will be described as an example. In addition, in FIG. 4, illustration of a release film is abbreviate|omitted.

As described above, the first surface 11a of the substrate 11 is an uneven surface. In addition, the pressure-sensitive adhesive layer 12 is formed in direct contact with the first side (corrugated surface) 11a of the substrate 11, and the second side 12b of the pressure-sensitive adhesive layer 12 is made of the base material 11. It becomes easy to follow one surface 11a. Accordingly, the second surface 12b of the pressure-sensitive adhesive layer 12 also becomes an uneven surface.

The thickness T _a of the pressure-sensitive adhesive layer 12 is not constant and fluctuates depending on the portion of the pressure-sensitive adhesive layer 12. Here, the minimum value of the thickness of the pressure-sensitive adhesive layer 12 is indicated by the symbol T _a1 , and the maximum value of the thickness of the pressure-sensitive adhesive layer 12 is indicated by the symbol T _a2 .

In the composite sheet 1A for forming a protective film, a test piece is cut out from the five places, and a cross section is formed from these five test pieces, and the minimum value (T _a1 ) and the maximum of the thickness of the pressure-sensitive adhesive layer in the newly formed cross section, respectively. The value (T _a2 ) is obtained. And, when the average value (the S value) is calculated|required from at least five values of T _a1 , it becomes 1.5 micrometers or more, and when the average value (the said L value) is calculated|required from at least five T _a2 values, it becomes 9 micrometers or less.

The cutting of the test piece from the composite sheet for forming a protective film (1A), the formation of the cross section in the test piece, and the measurement of the minimum value (T _a1 ) and the maximum value (T _a2 ) of the thickness of the pressure-sensitive adhesive layer in the cross section are , As described above, the same can be carried out as in the case where the test piece is cut out from the support sheet not including the composite sheet for forming a protective film.

On the other hand, the enlarged cross-sectional view of the support sheet which does not comprise the composite sheet for protective film formation is the same as that omitting the illustration of the protective film formation film 13 in FIG.

As the composite sheet 1A for forming a protective film, a region between the substrate 11 and the pressure-sensitive adhesive layer 12 in which they are not bonded (in this specification, it may be referred to as a “non-bonded region”) 91 Indicates that there is. However, even if the protective film-forming composite sheet 1A has such a non-bonded region 91, the size of the non-bonded region 91 in the thickness direction of the protective film-forming composite sheet 1A is, for example, 0.5 μm. It can be said that the following composite sheet 1A for forming a protective film has good lamination properties between the base material 11 and the pressure-sensitive adhesive layer 12 and has good properties.

In addition, in this specification, "the size of the non-bonded area in the thickness direction of the composite sheet for protective film formation" means "the interlayer distance in the thickness direction of the said sheet of two adjacent layers in the composite sheet for protective film formation" Means, and may be simply referred to as "the distance between floors". For example, the "size of the non-bonded region 91 in the thickness direction of the protective film-forming composite sheet 1A" means "the substrate 11 and the adhesive in the thickness direction of the sheet 1A. It means the interlayer distance between the layers 12".

When the size (interlayer distance) of one non-bonded area fluctuates, the maximum value is adopted as the size (interlayer distance) of the non-bonded area.

The size (interlayer distance) of the non-bonding region can be measured, for example, in the same manner as in the case of the thickness of the pressure-sensitive adhesive layer described above. That is, in the same manner as in determining the thickness of the pressure-sensitive adhesive layer, a cross section is formed in the test piece of the composite sheet for forming a protective film, and the size of the non-bonded region in this cross section can be determined. Alternatively, without producing a test piece, a cross section may be formed from the composite sheet for forming a protective film itself, and the size of the non-bonded region in this cross section may be determined.

The size of the non-bonded region 91 (the interlayer distance) may be, for example, any one of 0.4 μm or less, 0.3 μm or less, 0.2 μm or less, and 0.1 μm or less.

In the composite sheet 1A for forming a protective film, the non-bonded region 91 may not exist at all.

Here, the base material and the pressure-sensitive adhesive layer have been described taking the composite sheet 1A for forming a protective film as an example, but the composite for forming a protective film of another embodiment such as the composite sheet 1B for forming a protective film and the composite sheet 1C for forming a protective film. Also in the case of a sheet, the base material and the pressure-sensitive adhesive layer are the same.

If the S value of the pressure-sensitive adhesive layer is 1.5 μm or more and less than 9 μm, it is not particularly limited, but it is preferably 1.7 μm or more, more preferably 1.9 μm or more, and, for example, 2.3 μm or more, 2.7 μm or more, and 3.1 Either of µm or more and 3.5 µm or more may be used. When the S value is equal to or greater than the lower limit, the lamination property of the pressure-sensitive adhesive layer and the film for forming a protective film becomes more favorable.

On the other hand, the S value of the pressure-sensitive adhesive layer may be 8 μm or less, for example. Such an adhesive layer can be formed more easily.

The S value of the pressure-sensitive adhesive layer can be appropriately adjusted within a range set by arbitrarily combining the above-described preferred lower and upper limits. For example, the S value of the pressure-sensitive adhesive layer is preferably 1.5 to 8 μm, more preferably 1.7 to 8 μm, still more preferably 1.9 to 8 μm, for example, 2.3 to 8 μm, 2.7 to 8 μm. , 3.1 to 8 µm, and 3.5 to 8 µm may be used. However, these are examples of the S value of the pressure-sensitive adhesive layer.

The L value of the pressure-sensitive adhesive layer is 9 μm or less, and if it is greater than 1.5 μm, it is not particularly limited, but it is preferably 8.6 μm or less, more preferably 8.3 μm or less, for example, 7.7 μm or less, 7.3 μm or less, 6.9 Either of µm or less and 6.5 µm or less may be used. When the L value is less than or equal to the upper limit, the printing visibility through the support sheet of the protective film or the film for forming a protective film becomes more favorable.

On the other hand, the L value of the pressure-sensitive adhesive layer may be, for example, 2.5 μm or more. Such an adhesive layer can be formed more easily.

The L value of the pressure-sensitive adhesive layer can be appropriately adjusted within a range set by arbitrarily combining the above-described preferred lower and upper limits. For example, the L value of the pressure-sensitive adhesive layer is preferably 2.5 to 9 µm, more preferably 2.5 to 8.6 µm, still more preferably 2.5 to 8.3 µm, for example, 2.5 to 7.7 µm, 2.5 to 7.3 µm. , 2.5 to 6.9 μm, and 2.5 to 6.5 μm may be used.

The thickness of the pressure-sensitive adhesive layer (for example, T _a ) is not particularly limited as long as it satisfies the conditions of the S value and L value described above.

For example, the thickness of the pressure-sensitive adhesive layer may be 1.5 to 9 µm.

On the other hand, the "thickness of the adhesive layer" means the thickness of the entire pressure-sensitive adhesive layer, and for example, the thickness of the pressure-sensitive adhesive layer composed of a plurality of layers means the total thickness of all layers constituting the pressure-sensitive adhesive layer. From this point of view, the minimum and maximum values of the thickness of the pressure-sensitive adhesive layer are defined.

The adhesive layer contains an adhesive.

Examples of the pressure-sensitive adhesive include adhesive resins such as acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyvinyl ether, polycarbonate, and ester resins, and acrylic resins are preferable.

In this specification, "adhesive resin" is a concept including both a resin having adhesiveness and a resin having adhesiveness. For example, not only the resin itself has adhesiveness, but also in combination with other components such as additives Thus, resins exhibiting adhesiveness, resins exhibiting adhesiveness by the presence of a trigger such as heat or water are also included.

It is preferable that the pressure-sensitive adhesive layer is transparent.

The pressure-sensitive adhesive layer may be colored depending on the purpose.

For example, when the film for forming a protective film is energy ray-curable, it is preferable that the pressure-sensitive adhesive layer transmits energy rays.

The adhesive layer may be formed using an energy ray-curable adhesive, or may be formed using a non-energy ray-curable adhesive. The pressure-sensitive adhesive layer formed using an energy ray-curable pressure-sensitive adhesive can easily adjust physical properties before and after curing.

<<adhesive composition>>

The adhesive layer can be formed using an adhesive composition containing an adhesive. For example, by coating the pressure-sensitive adhesive composition on the surface to be formed of the pressure-sensitive adhesive layer and drying as necessary, the pressure-sensitive adhesive layer can be formed on a target site. A more specific method of forming the pressure-sensitive adhesive layer will be described later in detail together with a method of forming other layers. The ratio of the content of the components that do not vaporize at room temperature in the pressure-sensitive adhesive composition is usually the same as the ratio of the content of the components of the pressure-sensitive adhesive layer.

In the present specification, "room temperature" means a temperature that is not particularly cold or heated, that is, an ordinary temperature, and examples thereof include a temperature of 15 to 25°C.

Coating of the pressure-sensitive adhesive composition may be performed by a known method, for example, air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, meyer bar The method of using various coaters, such as a coater and a kiss coater, is mentioned.

Drying conditions of the pressure-sensitive adhesive composition are not particularly limited, but when the pressure-sensitive adhesive composition contains a solvent to be described later, it is preferable to heat-dry. It is preferable to dry the pressure-sensitive adhesive composition containing a solvent under the conditions of 10 seconds to 5 minutes at 70-130 degreeC, for example.

When the pressure-sensitive adhesive layer is energy ray-curable, the pressure-sensitive adhesive composition containing the energy-ray-curable pressure-sensitive adhesive, that is, the energy-ray-curable pressure-sensitive adhesive composition, includes, for example, a non-energy-ray-curable pressure-sensitive adhesive resin (I-1a) (hereinafter referred to as ``adhesive resin ( I-1a)") and the pressure-sensitive adhesive composition (I-1) containing an energy ray-curable compound; Containing an energy ray-curable adhesive resin (I-2a) in which an unsaturated group is introduced into the side chain of the non-energy ray-curable adhesive resin (I-1a) (hereinafter, it may be abbreviated as ``adhesive resin (I-2a)'') Pressure-sensitive adhesive composition (I-2); The adhesive composition (I-3) containing the said adhesive resin (I-2a) and an energy ray-curable compound, etc. are mentioned.

<Adhesive composition (I-1)>

As described above, the pressure-sensitive adhesive composition (I-1) contains a non-energy ray-curable adhesive resin (I-1a) and an energy ray-curable compound.

[Adhesive resin (I-1a)]

It is preferable that the said adhesive resin (I-1a) is an acrylic resin.

Examples of the acrylic resin include an acrylic polymer having at least a structural unit derived from an alkyl (meth)acrylate.

The constitutional units of the acrylic resin may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof may be arbitrarily selected.

Examples of the (meth)acrylate alkyl ester include those having 1 to 20 carbon atoms in the alkyl group constituting the alkyl ester, and the alkyl group is preferably a linear or branched chain.

As (meth)acrylate alkyl ester, more specifically, (meth) acrylate methyl, (meth) ethyl acrylate, (meth) acrylate n-propyl, (meth) acrylate isopropyl, (meth) acrylate n-butyl, (meth) acrylic acid Isobutyl, (meth)acrylic acid sec-butyl, (meth)acrylate tert-butyl, (meth)acrylate pentyl, (meth)acrylic acid hexyl, (meth)acrylate heptyl, (meth)acrylate 2-ethylhexyl, (meth)acrylic acid Isooctyl, (meth) acrylate n-octyl, (meth) acrylate n-nonyl, (meth) acrylate isononyl, (meth) acrylate, (meth) acrylate, (meth) acrylate, dodecyl ((meth) Lauryl acrylate), (meth)tridecyl acrylate, (meth) tetradecyl acrylate ((meth) myristyl acrylate), pentadecyl acrylate, (meth) hexadecyl acrylate ((meth) palmityl acrylate), ( Heptadecyl meth), octadecyl (meth) acrylate ((meth) stearyl acrylate), nonadecyl (meth) acrylate, and icosyl (meth) acrylate.

From the viewpoint of improving the adhesive strength of the pressure-sensitive adhesive layer, it is preferable that the acrylic polymer has a structural unit derived from an alkyl (meth)acrylate having 4 or more carbon atoms in the alkyl group. And since the adhesive force of the pressure-sensitive adhesive layer further improves, the alkyl group preferably has 4 to 12 carbon atoms, and more preferably 4 to 8 carbon atoms. Further, the alkyl group having 4 or more carbon atoms is preferably an alkyl acrylate ester.

It is preferable that the said acrylic polymer further has a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the (meth)acrylate alkyl ester.

As the functional group-containing monomer, for example, the functional group becomes a starting point for crosslinking by reacting with a crosslinking agent described below, or the functional group reacts with an unsaturated group in an unsaturated group-containing compound described later, thereby introducing an unsaturated group into the side chain of the acrylic polymer. What makes you do it.

Examples of the functional group in the functional group-containing monomer include a hydroxyl group, a carboxyl group, an amino group, and an epoxy group.

That is, as a functional group-containing monomer, a hydroxyl group-containing monomer, a carboxy group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, etc. are mentioned, for example.

Examples of the hydroxyl group-containing monomer include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and (meth)acrylate. ) (Meth)acrylate hydroxyalkyl such as 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; Non-(meth)acrylic unsaturated alcohols (unsaturated alcohols having no (meth)acryloyl skeleton), such as vinyl alcohol and allyl alcohol, may be mentioned.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; Ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as fumaric acid, itaconic acid, maleic acid and citraconic acid; Anhydrides of the ethylenically unsaturated dicarboxylic acids; (Meth)acrylic acid carboxyalkyl esters, such as 2-carboxyethyl methacrylate, etc. are mentioned.

As for the functional group-containing monomer, a hydroxyl group-containing monomer and a carboxy group-containing monomer are preferable, and a hydroxyl group-containing monomer is more preferable.

The functional group-containing monomer constituting the acrylic polymer may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the acrylic polymer, the content of the structural unit derived from the functional group-containing monomer is preferably 1 to 35% by mass, more preferably 2 to 30% by mass, and 3 to 27% by mass with respect to the total amount of the structural unit. It is particularly preferred.

In addition to the structural units derived from the (meth)acrylate alkyl ester and the structural units derived from the functional group-containing monomer, the acrylic polymer may further have a structural unit derived from another monomer.

The other monomer is not particularly limited as long as it is copolymerizable with an alkyl (meth)acrylate or the like.

Examples of the other monomers include styrene, α-methylstyrene, vinyl toluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

The other monomers constituting the acrylic polymer may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof may be arbitrarily selected.

The acrylic polymer can be used as the above-described non-energy ray-curable adhesive resin (I-1a).

On the other hand, what made the unsaturated group-containing compound which has an energy ray-polymerizable unsaturated group (energy ray-polymerizable group) react with the functional group in the said acrylic polymer can be used as the above-mentioned energy ray-curable adhesive resin (I-2a).

The adhesive resin (I-1a) contained in the pressure-sensitive adhesive composition (I-1) may be one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-1), the content of the pressure-sensitive adhesive resin (I-1a) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass with respect to the total mass of the pressure-sensitive adhesive composition (I-1). And it is particularly preferably 15 to 90% by mass.

[Energy ray curable compound]

Examples of the energy ray-curable compound contained in the pressure-sensitive adhesive composition (I-1) include a monomer or oligomer that has an energy ray-polymerizable unsaturated group and can be cured by irradiation with energy rays.

Among the energy ray-curable compounds, monomers include, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth) Polyhydric (meth)acrylates such as acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol (meth)acrylate; Urethane (meth)acrylate; Polyester (meth)acrylate; Polyether (meth)acrylate; Epoxy (meth)acrylate, etc. are mentioned.

Among the energy ray-curable compounds, oligomers include, for example, oligomers obtained by polymerization of the monomers exemplified above.

The energy ray-curable compound is preferably a urethane (meth)acrylate or urethane (meth)acrylate oligomer in that it has a relatively large molecular weight and is difficult to lower the storage modulus of the pressure-sensitive adhesive layer.

The energy ray-curable compound contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-1), the content of the energy ray-curable compound is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, based on the total mass of the pressure-sensitive adhesive composition (I-1). , It is particularly preferably 10 to 85% by mass.

[Crosslinking agent]

When using the above acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from an alkyl (meth)acrylate as the adhesive resin (I-1a), the pressure-sensitive adhesive composition (I-1) is additionally a crosslinking agent. It is preferable to contain.

The crosslinking agent crosslinks the adhesive resins (I-1a) by reacting with the functional group, for example.

Examples of the crosslinking agent include isocyanate-based crosslinking agents (crosslinking agents having an isocyanate group) such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; Epoxy-based crosslinking agents such as ethylene glycol glycidyl ether (crosslinking agents having a glycidyl group); Aziridine-based crosslinking agents such as hexa[1-(2-methyl)-aziridinyl]triphosphatriazine (crosslinking agents having an aziridinyl group); Metal chelate-based crosslinking agents such as aluminum chelate (crosslinking agents having a metal chelate structure); Isocyanurate-based crosslinking agents (crosslinking agents having an isocyanuric acid skeleton), and the like.

It is preferable that the crosslinking agent is an isocyanate-based crosslinking agent from the viewpoints of improving the cohesiveness of the pressure-sensitive adhesive to improve the adhesion of the pressure-sensitive adhesive layer, and being easily available.

The crosslinking agent contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-1), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and more preferably 0.3 to 15 parts by mass based on 100 parts by mass of the content of the adhesive resin (I-1a). It is particularly preferably parts by mass.

[Photopolymerization initiator]

The pressure-sensitive adhesive composition (I-1) may further contain a photoinitiator. Even if the pressure-sensitive adhesive composition (I-1) containing a photoinitiator is irradiated with relatively low energy energy rays such as ultraviolet rays, the curing reaction sufficiently proceeds.

Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, and benzoin dimethyl ketal. Phosphorus compounds; Acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and 2,2-dimethoxy-1,2-diphenylethan-1-one; Acylphosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; Sulfide compounds such as benzylphenyl sulfide and tetramethylthiuram monosulfide; Α-ketol compounds such as 1-hydroxycyclohexylphenyl ketone; Azo compounds such as azobisisobutyronitrile; Titanocene compounds such as titanocene; Thioxanthone compounds such as thioxanthone; Peroxide compounds; Diketone compounds such as diacetyl; benzyl; Dibenzyl; Benzophenone; 2,4-diethyl thioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; 2-chloroanthraquinone, etc. are mentioned.

Further, examples of the photopolymerization initiator include quinone compounds such as 1-chloroanthraquinone; A photosensitizer such as amine can also be used.

The photoinitiators contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The content of the photopolymerization initiator in the pressure-sensitive adhesive composition (I-1) is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and more preferably 0.05 to 5 parts by mass based on 100 parts by mass of the content of the energy ray-curable compound. It is particularly preferred.

[Other additives]

The pressure-sensitive adhesive composition (I-1) may contain other additives which do not correspond to any of the above-described components within a range that does not impair the effects of the present invention.

Examples of the above other additives include antistatic agents, antioxidants, softeners (plasticizers), fillers (fillers), rust inhibitors, colorants (pigments, dyes), sensitizers, tackifiers, reaction retardants, crosslinking accelerators (catalysts ), and other known additives.

On the other hand, the reaction retarding agent is to suppress the progress of an undesired crosslinking reaction in the pressure-sensitive adhesive composition (I-1) during storage due to, for example, the action of a catalyst incorporated in the pressure-sensitive adhesive composition (I-1). . Examples of the reaction retarding agent include forming a chelate complex by chelate to a catalyst, and more specifically, one having two or more carbonyl groups (-C(=O)-) in one molecule. .

The other additives contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The content of the other additives in the pressure-sensitive adhesive composition (I-1) is not particularly limited, and may be appropriately selected according to the kind.

[menstruum]

The adhesive composition (I-1) may contain a solvent. When the pressure-sensitive adhesive composition (I-1) contains a solvent, the application aptitude to the surface to be coated is improved.

The solvent is preferably an organic solvent, and examples of the organic solvent include ketones such as methyl ethyl ketone and acetone; Esters such as ethyl acetate (carboxylic acid ester); Ethers such as tetrahydrofuran and dioxane; Aliphatic hydrocarbons such as cyclohexane and n-hexane; Aromatic hydrocarbons such as toluene and xylene; Alcohol, such as 1-propanol and 2-propanol, etc. are mentioned.

As the solvent, for example, what was used in the production of the adhesive resin (I-1a) may be used as it is in the adhesive composition (I-1) without removing from the adhesive resin (I-1a), or the adhesive resin ( The same or different types of solvents used in the production of I-1a) may be added separately during the production of the pressure-sensitive adhesive composition (I-1).

The solvent contained in the pressure-sensitive adhesive composition (I-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-1), the content of the solvent is not particularly limited and may be appropriately adjusted.

<Adhesive composition (I-2)>

As described above, the pressure-sensitive adhesive composition (I-2) contains an energy-ray-curable pressure-sensitive adhesive resin (I-2a) in which an unsaturated group is introduced into the side chain of the non-energy-ray-curable pressure-sensitive adhesive resin (I-1a).

[Adhesive resin (I-2a)]

The adhesive resin (I-2a) is obtained, for example, by reacting a functional group in the adhesive resin (I-1a) with an unsaturated group-containing compound having an energy ray-polymerizable unsaturated group.

The unsaturated group-containing compound is a compound having a group capable of bonding to the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a) in addition to the energy ray-polymerizable unsaturated group.

Examples of the energy ray-polymerizable unsaturated group include a (meth)acryloyl group, a vinyl group (ethenyl group), an allyl group (2-propenyl group), and the like, and a (meth)acryloyl group is preferable.

Examples of groups that can be bonded to functional groups in the adhesive resin (I-1a) include isocyanate groups and glycidyl groups that can be bonded to hydroxyl groups or amino groups, and hydroxyl groups and amino groups that can be bonded to carboxyl groups or epoxy groups.

Examples of the unsaturated group-containing compound include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

The adhesive resin (I-2a) contained in the pressure-sensitive adhesive composition (I-2) may be one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-2), the content of the pressure-sensitive adhesive resin (I-2a) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass with respect to the total mass of the pressure-sensitive adhesive composition (I-2). And it is particularly preferably 10 to 90% by mass.

[Crosslinking agent]

In the case of using the acrylic polymer having structural units derived from monomers containing the same functional group as those in the adhesive resin (I-1a), for example, the adhesive composition (I-2) is added It may contain a cross-linking agent.

Examples of the crosslinking agent in the pressure-sensitive adhesive composition (I-2) include those similar to the crosslinking agent in the pressure-sensitive adhesive composition (I-1).

The crosslinking agent contained in the pressure-sensitive adhesive composition (I-2) may be one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The content of the crosslinking agent in the pressure-sensitive adhesive composition (I-2) is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and more preferably 0.3 to 15 parts by mass based on 100 parts by mass of the content of the adhesive resin (I-2a). It is particularly preferably parts by mass.

[Photopolymerization initiator]

The pressure-sensitive adhesive composition (I-2) may further contain a photoinitiator. Even if the pressure-sensitive adhesive composition (I-2) containing a photoinitiator is irradiated with relatively low energy energy rays such as ultraviolet rays, the curing reaction sufficiently proceeds.

Examples of the photopolymerization initiator in the pressure-sensitive adhesive composition (I-2) include those similar to the photopolymerization initiator in the pressure-sensitive adhesive composition (I-1).

The photoinitiators contained in the pressure-sensitive adhesive composition (I-2) may be one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The content of the photoinitiator in the pressure-sensitive adhesive composition (I-2) is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and more preferably 0.05 to 5 parts by mass based on 100 parts by mass of the content of the adhesive resin (I-2a). It is particularly preferably parts by mass.

[Other additives]

The pressure-sensitive adhesive composition (I-2) may contain other additives that do not correspond to any of the above-described components within a range that does not impair the effects of the present invention.

Examples of the other additives in the pressure-sensitive adhesive composition (I-2) include those similar to other additives in the pressure-sensitive adhesive composition (I-1).

The other additives contained in the pressure-sensitive adhesive composition (I-2) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The content of the other additives in the pressure-sensitive adhesive composition (I-2) is not particularly limited, and may be appropriately selected according to the type.

[menstruum]

The pressure-sensitive adhesive composition (I-2) may contain a solvent for the same purpose as in the case of the pressure-sensitive adhesive composition (I-1).

Examples of the solvent in the pressure-sensitive adhesive composition (I-2) include those similar to the solvent in the pressure-sensitive adhesive composition (I-1).

The number of solvents contained in the pressure-sensitive adhesive composition (I-2) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-2), the content of the solvent is not particularly limited and may be appropriately adjusted.

<Adhesive composition (I-3)>

As described above, the pressure-sensitive adhesive composition (I-3) contains the pressure-sensitive adhesive resin (I-2a) and an energy ray-curable compound.

In the adhesive composition (I-3), the content of the adhesive resin (I-2a) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, based on the total mass of the adhesive composition (I-3). And it is particularly preferably 15 to 90% by mass.

[Energy ray curable compound]

Examples of the energy ray-curable compound contained in the pressure-sensitive adhesive composition (I-3) include monomers and oligomers that have an energy-ray polymerizable unsaturated group and can be cured by irradiation with energy rays, and the pressure-sensitive adhesive composition (I-1) contains The same thing as the energy ray-curable compound is mentioned.

The energy ray-curable compound contained in the pressure-sensitive adhesive composition (I-3) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-3), the content of the energy ray-curable compound is preferably 0.01 to 300 parts by mass, more preferably 0.03 to 200 parts by mass, based on 100 parts by mass of the content of the adhesive resin (I-2a). And 0.05 to 100 parts by mass is particularly preferred.

[Photopolymerization initiator]

The pressure-sensitive adhesive composition (I-3) may further contain a photoinitiator. Even if the pressure-sensitive adhesive composition (I-3) containing a photoinitiator is irradiated with relatively low energy energy rays such as ultraviolet rays, the curing reaction sufficiently proceeds.

Examples of the photopolymerization initiator in the pressure-sensitive adhesive composition (I-3) include the same as those of the photopolymerization initiator in the pressure-sensitive adhesive composition (I-1).

The photoinitiators contained in the pressure-sensitive adhesive composition (I-3) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-3), the content of the photoinitiator is preferably 0.01 to 20 parts by mass, and 0.03 to 10 parts by mass based on 100 parts by mass of the total content of the adhesive resin (I-2a) and the energy ray-curable compound. It is more preferable and it is especially preferable that it is 0.05-5 mass parts.

[Other additives]

The pressure-sensitive adhesive composition (I-3) may contain other additives which do not correspond to any of the above-described components within a range that does not impair the effects of the present invention.

As said other additive, the same thing as other additives in the adhesive composition (I-1) is mentioned.

The other additives contained in the pressure-sensitive adhesive composition (I-3) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The content of the other additives in the pressure-sensitive adhesive composition (I-3) is not particularly limited, and may be appropriately selected according to the type.

[menstruum]

The pressure-sensitive adhesive composition (I-3) may contain a solvent for the same purpose as in the case of the pressure-sensitive adhesive composition (I-1).

Examples of the solvent in the pressure-sensitive adhesive composition (I-3) include those similar to the solvent in the pressure-sensitive adhesive composition (I-1).

The solvent contained in the pressure-sensitive adhesive composition (I-3) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-3), the content of the solvent is not particularly limited and may be appropriately adjusted.

<Adhesive compositions other than adhesive compositions (I-1) to (I-3)>

Until now, the pressure-sensitive adhesive composition (I-1), the pressure-sensitive adhesive composition (I-2), and the pressure-sensitive adhesive composition (I-3) have been mainly described, but what has been described as the components they contain is an overall pressure-sensitive adhesive composition other than these three pressure-sensitive adhesive compositions. (In the present specification, it is referred to as "adhesive compositions other than adhesive compositions (I-1) to (I-3)").

As the pressure-sensitive adhesive compositions other than the pressure-sensitive adhesive compositions (I-1) to (I-3), in addition to the energy-ray-curable pressure-sensitive adhesive composition, a non-energy-ray-curable pressure-sensitive adhesive composition is also mentioned.

Examples of the non-energy ray-curable adhesive composition include non-energy ray-curable adhesive resins (I-1a) such as acrylic resin, urethane resin, rubber resin, silicone resin, epoxy resin, polyvinyl ether, polycarbonate, ester resin, etc. ) Containing the pressure-sensitive adhesive composition (I-4), preferably containing an acrylic resin.

It is preferable that the pressure-sensitive adhesive compositions other than the pressure-sensitive adhesive compositions (I-1) to (I-3) contain one or two or more crosslinking agents, and the content thereof is the same as in the case of the pressure-sensitive adhesive composition (I-1) described above. can do.

<Adhesive composition (I-4)>

As preferable thing as the adhesive composition (I-4), what contains the said adhesive resin (I-1a) and a crosslinking agent is mentioned, for example.

[Adhesive resin (I-1a)]

As the adhesive resin (I-1a) in the adhesive composition (I-4), the same thing as the adhesive resin (I-1a) in the adhesive composition (I-1) can be mentioned.

The adhesive resin (I-1a) contained in the pressure-sensitive adhesive composition (I-4) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the adhesive composition (I-4), the content of the adhesive resin (I-1a) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, based on the total mass of the adhesive composition (I-4). And it is particularly preferably 15 to 90% by mass.

In the adhesive composition (I-4), the ratio of the content of the adhesive resin (I-1a) to the total content of all components other than the solvent (that is, the content of the adhesive resin (I-1a) in the adhesive layer) is 30 to 90 It is preferable that it is a mass %, it is more preferable that it is 40 to 85 mass %, It is especially preferable that it is 50 to 80 mass %.

[Crosslinking agent]

In the case of using the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from an alkyl (meth)acrylate as the adhesive resin (I-1a), the adhesive composition (I-4) is additionally a crosslinking agent. It is preferable to contain.

Examples of the crosslinking agent in the pressure-sensitive adhesive composition (I-4) include the same as the crosslinking agent in the pressure-sensitive adhesive composition (I-1).

The crosslinking agent contained in the pressure-sensitive adhesive composition (I-4) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-4), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass, more preferably 0.3 to 50 parts by mass, and more preferably 1 to 50 parts by mass based on 100 parts by mass of the adhesive resin (I-1a). It is more preferable that it is a mass part, and for example, any one of 10-50 mass parts, 15-50 mass parts, 20-50 mass parts, etc. may be sufficient.

[Other additives]

The pressure-sensitive adhesive composition (I-4) may contain other additives which do not correspond to any of the above-described components within a range that does not impair the effects of the present invention.

As said other additive, the same thing as other additives in the adhesive composition (I-1) is mentioned.

The other additives contained in the pressure-sensitive adhesive composition (I-4) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The content of the other additives in the pressure-sensitive adhesive composition (I-4) is not particularly limited, and may be appropriately selected according to the type.

[menstruum]

The pressure-sensitive adhesive composition (I-4) may contain a solvent for the same purpose as in the case of the pressure-sensitive adhesive composition (I-1).

Examples of the solvent in the pressure-sensitive adhesive composition (I-4) include those similar to the solvent in the pressure-sensitive adhesive composition (I-1).

The number of solvents contained in the pressure-sensitive adhesive composition (I-4) may be only one, may be two or more, and in the case of two or more, combinations and ratios thereof can be arbitrarily selected.

In the pressure-sensitive adhesive composition (I-4), the content of the solvent is not particularly limited and may be appropriately adjusted.

In the composite sheet for forming a protective film, the pressure-sensitive adhesive layer is preferably non-energy ray-curable. This is because if the pressure-sensitive adhesive layer is energy ray-curable, when curing the protective film-forming film by irradiation with energy rays, it is sometimes impossible to suppress curing of the pressure-sensitive adhesive layer at the same time. When the pressure-sensitive adhesive layer is cured at the same time as the protective film-forming film, the cured protective film-forming film (that is, the protective film) and the pressure-sensitive adhesive layer may be affixed to the extent that peeling is impossible at these interfaces. In that case, it becomes difficult to peel the film for forming a protective film after curing, that is, the semiconductor chip provided with the protective film on the back surface from the support sheet provided with the pressure-sensitive adhesive layer after curing, and the semiconductor chip with the protective film is normally You will not be able to pick up. By making the pressure-sensitive adhesive layer in the support sheet non-energy ray-curable, such a problem can be reliably avoided, and the semiconductor chip on which the protective film is formed can be picked up more easily.

Here, the effect of the case where the pressure-sensitive adhesive layer is non-energy ray-curable has been described, but even if the layer in direct contact with the protective film-forming film of the support sheet is a layer other than the pressure-sensitive adhesive layer, the same Shows the effect.

<<the manufacturing method of an adhesive composition>>

Pressure-sensitive adhesive compositions other than pressure-sensitive adhesive compositions (I-1) to (I-3), such as pressure-sensitive adhesive compositions (I-1) to (I-3) and pressure-sensitive adhesive compositions (I-4), may be used as the pressure-sensitive adhesive and, if necessary, It is obtained by blending each component for constituting an adhesive composition such as components other than the adhesive.

The order of addition at the time of compounding each component is not particularly limited, and two or more components may be added simultaneously.

In the case of using a solvent, it may be used by mixing the solvent with any of the components other than the solvent and diluting the component in advance, and without pre-diluting any of the components other than the solvent, You may use it by mixing with these compounding components.

The method of mixing each component at the time of mixing is not particularly limited, and a method of mixing by rotating a stirrer or a stirring blade, etc.; Mixing using a mixer; What is necessary is just to select suitably from well-known methods, such as a method of adding ultrasonic waves and mixing.

The temperature and time at the time of addition and mixing of each component are not particularly limited as long as each compounding component does not deteriorate, and may be appropriately adjusted, but the temperature is preferably 15 to 30°C.

◎ Film for forming a protective film

The film for forming a protective film becomes a protective film as it is by curing or without curing. This protective film is for protecting the back surface (the side opposite to the electrode formation surface) of the semiconductor wafer or semiconductor chip. The film for forming a protective film is soft and can be easily affixed to the object to be pasted.

The film for forming a protective film may be curable or non-curable.

The film for curable protective film formation may be any of thermosetting and energy ray curing properties, and may have both properties of thermosetting and energy ray curing properties.

The film for protective film formation can be formed using a composition for forming a protective film containing the constituent material.

In the present specification, "non-curing" means a property that is not cured by any means such as heating or irradiation with energy rays.

In the present invention, even after the protective film-forming film has been cured, as long as the laminated structure of the support sheet and the cured product of the protective film-forming film (that is, the support sheet and the protective film) is maintained, this laminate is referred to as "protective film formation. It is called "the composite sheet for use".

Regardless of the kind, the protective film-forming film may consist of one layer (single layer), or may consist of a plurality of layers of two or more layers. When the film for protective film formation consists of multiple layers, these multiple layers may be the same or different from each other.

Here again, referring to FIG. 4, the pressure-sensitive adhesive layer and the film for forming a protective film will be described in more detail.

As described above, the first surface 11a of the substrate 11 is an uneven surface. However, in the pressure-sensitive adhesive layer 12, when the S value is 1.5 μm or more, the influence of the uneven surface is suppressed, and the degree of unevenness on the first surface 12a of the pressure-sensitive adhesive layer 12 is reduced. . For this reason, the lamination property of the adhesive layer 12 and the film 13 for protective film formation becomes favorable. For example, even if there exist areas (non-bonded areas) 92 between the pressure-sensitive adhesive layer 12 and the protective film-forming film 13, the number is the composite sheet for forming a protective film 1A It becomes very few, such as 3 or less over the entire formation region of the film 13 for forming a protective film in the middle. The non-bonded region 92 can be easily confirmed by observing the composite sheet 1A for forming a protective film from the side of the substrate 11, for example.

In addition, even if the protective film-forming composite sheet 1A has such a non-bonded region 92, the size (interlayer distance) of the non-bonded region 92 in the thickness direction of the protective film-forming composite sheet 1A is exemplified. For example, in the composite sheet 1A for forming a protective film of 0.5 μm or less, the lamination property of the pressure-sensitive adhesive layer 12 and the film 13 for forming a protective film is better. Here, the "size (interlayer distance) of the non-bonding region 92" means "the interlayer distance between the pressure-sensitive adhesive layer 12 and the protective film-forming film 13 in the thickness direction of the protective film-forming composite sheet 1A" Means ".

The size of the non-bonded area 92 (the interlayer distance) is preferably 0.5 μm or less, the same as the interlayer distance (size) of the non-bonded area 91, and, for example, 0.4 μm or less, 0.3 μm or less , 0.2 μm or less, and 0.1 μm or less may be used.

The size (interlayer distance) of the non-bonded area 92 can be obtained in the same manner as in the case of the size (interlayer distance) of the non-bonded area 91 described above, except that the target combination of the two layers is different. I can.

In the composite sheet 1A for forming a protective film, the non-bonded region 92 may not exist at all.

On the other hand, as described above, the degree of unevenness on the first surface 12a of the pressure-sensitive adhesive layer 12 is decreasing. For this reason, the thickness T _{p of the} protective film-forming film 13 is not constant, and fluctuates depending on the portion of the protective film-forming film 13 (adhesive layer 12), but its variation is very small.

In addition, since the unevenness on the first surface 12a of the pressure-sensitive adhesive layer 12 is reduced as described above, the pressure-sensitive adhesive layer 12 side surface (second surface) 13b of the protective film-forming film 13 ) Is smooth or the unevenness is getting smaller. Therefore, the appearance of the protective film-forming film 13 is not impaired.

And also in the protective film formed from the protective film-forming film 13, the pressure-sensitive adhesive layer 12 side surface (the second surface) is smooth or the unevenness becomes small, and the appearance of the protective film remains unaffected.

In this way, in the protective film-forming composite sheet 1A, both the protective film-forming film 13 and the protective film can have excellent design properties.

In the second surface 13b of the protective film-forming film 13, the maximum height difference between the highest portion of the convex portion and the deepest portion of the concave portion is preferably 2 μm or less, for example, 1.5 μm or less and 1 μm or less. Any one of them may be sufficient. The protective film-forming film 13 and the protective film are particularly excellent in design.

The maximum height difference in the second surface 13b of the protective film-forming film 13 is, for example, the cross section of the protective film-forming composite sheet itself or the test piece of the protective film-forming composite sheet by the method described above. It can be obtained by forming and observing this cross section using a scanning electron microscope (SEM).

Here, the pressure-sensitive adhesive layer and the protective film-forming film have been described taking the protective film-forming composite sheet 1A as an example, but the protective film of another embodiment such as the protective film-forming composite sheet 1B and the protective film-forming composite sheet 1C Also in the case of the forming composite sheet, the pressure-sensitive adhesive layer and the film for forming a protective film are the same.

In the composite sheet for forming a protective film of the present invention, the thickness (for example, T _p ) of the film for forming a protective film is preferably 1 to 100 μm, more preferably 3 to 75 μm, and 5 to 50 μm. It is particularly preferred. When the thickness of the protective film-forming film is equal to or greater than the lower limit, a protective film having a higher protective ability can be formed. When the thickness of the protective film-forming film is equal to or less than the upper limit, excessive thickness is suppressed.

When the thickness of the protective film-forming film varies depending on the portion of the protective film-forming film, the minimum value of the thickness of the protective film-forming film may be equal to or greater than the lower limit, and even if the maximum value of the thickness of the protective film-forming film is less than or equal to the upper limit. do.

On the other hand, "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 multiple layers is the sum of all layers constituting the protective film-forming film. Means the thickness of.

The thickness of the protective film-forming film can be measured, for example, by observing the side surface or the cross section of the protective film-forming film using a scanning electron microscope (SEM).

The cross section of the film for forming a protective film can be formed by the same method as in the case of the cross section of the test piece of the support sheet and the composite sheet for forming a protective film described above, for example.

For example, by cutting out a test piece from a plurality of locations (e.g., 5 locations) of a composite sheet for forming a protective film by the method described above, the minimum and maximum values of the thickness of the film for forming a protective film in this test piece are obtained, and these When the average value of these minimum values and the average values of the maximum values are further calculated from the value of, the average value of the minimum value may be equal to or greater than the lower limit of the thickness of the film for forming a protective film, and the average value of the maximum value is that of the film for forming a protective film. It may be less than or equal to the upper limit of the thickness.

The film for protective film formation can be formed using a composition for forming a protective film containing the constituent material. For example, a protective film-forming film can be formed on a target site by coating the protective film-forming composition on the surface to be formed on the protective film-forming film and drying it as necessary. The ratio of the content of the components that do not vaporize at room temperature in the protective film-forming composition is usually equal to the ratio of the content of the components of the protective film-forming film.

Coating of the composition for formation of protection may be performed by a known method, for example, an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater, a screen coater, The method of using various coaters, such as a Mayer bar coater and a kiss coater, is mentioned.

Drying conditions of the composition for forming a protective film are not particularly limited, but when the composition for forming a protective film contains a solvent described later, it is preferable to heat-dry. In addition, the composition for forming a protective film containing a solvent is preferably dried at 70 to 130°C for 10 seconds to 5 minutes. However, when the composition for forming a protective film is thermosetting, it is preferable to dry the composition for forming a protective film so that the film for forming a protective film to be formed is not thermally cured.

Hereinafter, the protective film-forming film and the protective film-forming composition will be described in detail for each type.

○ Film for forming a thermosetting protective film

As a preferable film for thermosetting protective film formation, what contains a polymer component (A) and a thermosetting component (B) is mentioned, for example.

The polymer component (A) is a component that can be considered to be formed by a polymerization reaction of a polymerizable compound.

The thermosetting component (B) is a component capable of curing (polymerization) reaction using heat as a trigger of the reaction. On the other hand, in the present invention, the polymerization reaction also includes a polycondensation reaction.

The curing conditions at the time of thermosetting after the film for forming a thermosetting protective film is affixed to the back surface of a semiconductor wafer is not particularly limited as long as the curing degree is such that the cured product sufficiently exhibits its function, and the kind of film for forming a thermosetting protective film You just need to select it appropriately according to.

For example, the heating temperature during thermosetting of the thermosetting protective film forming film is preferably 100 to 200°C, more preferably 110 to 180°C, and particularly preferably 120 to 170°C. Further, the heating time at the time of curing is preferably 0.5 to 5 hours, more preferably 0.5 to 3 hours, and particularly preferably 1 to 2 hours.

<Composition for forming a thermosetting protective film (III-1)>

As a preferable composition for forming a thermosetting protective film, for example, a composition for forming a thermosetting protective film (III-1) containing a polymer component (A) and a thermosetting component (B) (in this specification, simply ``composition (III-1) It may be abbreviated as ").

[Polymer component (A)]

The polymer component (A) is a component for imparting film-forming properties, flexibility, and the like to the film for forming a thermosetting protective film.

The composition (III-1) and the polymer component (A) contained in the film for forming a thermosetting protective film may be one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

Examples of the polymer component (A) include acrylic resins, polyesters, urethane resins, acrylic urethane resins, silicone resins, rubber resins, phenoxy resins, thermosetting polyimides, and acrylic resins.

Known acrylic polymers can be mentioned as the acrylic resin in the polymer component (A).

It is preferable that it is 10000-2000000, and, as for the weight average molecular weight (Mw) of an acrylic resin, it is more preferable that it is 100000-150,000. When the weight average molecular weight of the acrylic resin is equal to or greater than the above lower limit, the shape stability (stability with time during storage) of the film for forming a thermosetting protective film is improved. In addition, when the weight average molecular weight of the acrylic resin is less than or equal to the above upper limit, the film for forming a thermosetting protective film is easier to follow on the uneven surface of the adherend, and the occurrence of voids, etc. between the adherend and the film for forming a thermosetting protective film is more suppressed. .

In this specification, the weight average molecular weight is a polystyrene conversion value measured by a gel permeation chromatography (GPC) method unless otherwise noted.

It is preferable that it is -60 to 70 degreeC, and, as for the glass transition temperature (Tg) of an acrylic resin, it is more preferable that it is -30 to 50 degreeC. When Tg of the acrylic resin is equal to or greater than the above lower limit, for example, the adhesion between the cured product (ie, the protective film) of the protective film-forming film and the support sheet is suppressed, and the peelability of the support sheet is appropriately improved. Further, when the Tg of the acrylic resin is equal to or less than the above upper limit, the adhesion between the film for forming a thermosetting protective film and the adherend of the protective film is improved.

Meanwhile, the Tg of the resin in the present specification is not limited to an acrylic resin, for example, using a differential scanning calorimeter (DSC) as a temperature increase rate or a temperature decrease rate of 10°C/min, and between -70°C and 150°C. It can be calculated|required by changing the temperature of a measurement object and confirming an inflection point.

Examples of the acrylic resin include polymers of one or two or more (meth)acrylic acid esters; Copolymers of two or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide, and the like.

The (meth)acrylic acid ester constituting the acrylic resin includes, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n- (meth)acrylate. Butyl, (meth) isobutyl acrylate, (meth) acrylate sec-butyl, (meth) acrylate tert-butyl, (meth) acrylate, pentyl (meth) acrylate, (meth) heptyl acrylate, (meth) acrylate 2-ethyl Hexyl, (meth) acrylate isooctyl, (meth) acrylate n-octyl, (meth) acrylate n-nonyl, (meth) acrylate isononyl, (meth) acrylate, (meth) acrylate, (meth) acrylic acid Dodecyl ((meth) acrylate lauryl), (meth) acrylate tridecyl, (meth) acrylate tetradecyl ((meth) acrylate myristylus), (meth) acrylate pentadecyl, (meth) acrylate hexadecyl ((meth) (Meth)acrylic acid alkyl ester in which the alkyl group constituting the alkyl ester such as palmityl acrylate), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate ((meth) acrylate stearyl) has a chain structure having 1 to 18 carbon atoms ;

Cycloalkyl esters of (meth)acrylates such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate;

(Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate;

(Meth) acrylate cycloalkenyl ester, such as (meth) acrylate dicyclopentenyl ester;

(Meth)acrylate cycloalkenyloxyalkyl esters such as dicyclopentenyloxyethyl (meth)acrylate;

Imide (meth)acrylate;

Glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate;

Hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, (meth) ) Hydroxyl group-containing (meth)acrylic acid esters such as 3-hydroxybutyl acrylic acid and 4-hydroxybutyl (meth)acrylate;

And substituted amino group-containing (meth)acrylic acid esters such as N-methylaminoethyl (meth)acrylate. Here, the "substituted amino group" means a group obtained by substituting one or two hydrogen atoms of an amino group with a group other than a hydrogen atom.

The acrylic resin is, for example, in addition to the (meth)acrylic acid ester, one or two or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene and N-methylolacrylamide, etc. It may be formed by copolymerization.

The number of monomers constituting the acrylic resin may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The acrylic resin may have a functional group capable of bonding with other compounds such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, and an isocyanate group. The functional group of the acrylic resin may be bonded to another compound via a crosslinking agent (F) described later, or may be directly bonded to another compound without a crosslinking agent (F). When the acrylic resin is bonded to another compound by the functional group, the reliability of the package obtained using the composite sheet for forming a protective film tends to improve.

In the present invention, as the polymer component (A), a thermoplastic resin other than acrylic resin (hereinafter, simply abbreviated as ``thermoplastic resin'' in some cases) may be used alone without using an acrylic resin, or in combination with an acrylic resin. You can do it. By using the thermoplastic resin, the peelability of the protective film from the supporting sheet is improved, or the film for forming a thermosetting protective film is easier to follow on the uneven surface of the adherend, and voids, etc., are generated between the adherend and the film for forming a thermosetting protective film. It may be more suppressed.

It is preferable that it is 1000-100000, and, as for the weight average molecular weight of the said thermoplastic resin, it is more preferable that it is 3000-80000.

The glass transition temperature (Tg) of the thermoplastic resin is preferably -30 to 150°C, more preferably -20 to 120°C.

Examples of the thermoplastic resin include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

The thermoplastic resin contained in the composition (III-1) and the film for forming a thermosetting protective film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The ratio of the content of the polymer component (A) to the total content of all components other than the solvent in the composition (III-1) (that is, the content of the polymer component (A) of the film for forming a thermosetting protective film) is the polymer component (A ), it is preferably 5 to 85% by mass, more preferably 5 to 75% by mass, and for example, 5 to 65% by mass, 5 to 50% by mass, and 10 to 35% by mass, etc. Any one of them may be sufficient.

The polymer component (A) may also correspond to the thermosetting component (B). In the present invention, when the composition (III-1) contains components corresponding to both the polymer component (A) and the thermosetting component (B), the composition (III-1) is the polymer component (A) and the thermosetting component It is considered to contain (B).

[Thermosetting component (B)]

The thermosetting component (B) is a component for curing the film for forming a thermosetting protective film.

The composition (III-1) and the thermosetting component (B) contained in the film for forming a thermosetting protective film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyimides, polyurethanes, unsaturated polyesters, and silicone resins, and epoxy-based thermosetting resins are preferred.

(Epoxy thermosetting resin)

The epoxy-based thermosetting resin is composed of an epoxy resin (B1) and a thermosetting agent (B2).

The composition (III-1) and the epoxy-based thermosetting resin contained in the film for forming a thermosetting protective film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

Epoxy resin (B1)

Known epoxy resins (B1) include, for example, polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and hydrogenated products thereof, orthocresol novolac epoxy resins, dicyclopentadiene Epoxy compounds of bifunctional or higher functionalities, such as a type epoxy resin, a biphenyl type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a phenylene skeleton type epoxy resin, are mentioned.

As the epoxy resin (B1), an epoxy resin having an unsaturated hydrocarbon group may be used. The epoxy resin having an unsaturated hydrocarbon group has higher compatibility with an acrylic resin than an epoxy resin having no unsaturated hydrocarbon group. For this reason, by using an epoxy resin having an unsaturated hydrocarbon group, the reliability of a semiconductor chip with a protective film obtained using the composite sheet for forming a protective film is improved.

Examples of the epoxy resin having an unsaturated hydrocarbon group include compounds obtained by converting a part of the epoxy group of a polyfunctional epoxy resin into a group having an unsaturated hydrocarbon group. Such a compound is obtained, for example, by adding (meth)acrylic acid or a derivative thereof to an epoxy group.

Further, examples of the epoxy resin having an unsaturated hydrocarbon group include compounds in which a group having an unsaturated hydrocarbon group is directly bonded to the aromatic ring constituting the epoxy resin, for example.

The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include ethenyl group (vinyl group), 2-propenyl group (allyl group), (meth)acryloyl group, and (meth)acrylamide group, Acryloyl groups are preferred.

The number average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoints of curability of the film for forming a thermosetting protective film, and the strength and heat resistance of the protective film after curing, it is preferably 300 to 30,000, more preferably 300 to 10000. And it is particularly preferably 300 to 3000.

In this specification, the number average molecular weight is a polystyrene conversion value measured by a gel permeation chromatography (GPC) method unless otherwise noted.

It is preferable that it is 100-1000 g/eq, and, as for the epoxy equivalent of the epoxy resin (B1), it is more preferable that it is 150-950 g/eq.

Epoxy resin (B1) may be used individually by 1 type, may use 2 or more types together, and when 2 or more types are used together, these combinations and ratios can be selected arbitrarily.

·Heat curing agent (B2)

The thermal curing agent (B2) functions as a curing agent for the epoxy resin (B1).

Examples of the thermosetting agent (B2) include a compound having two or more functional groups capable of reacting with an epoxy group per molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, a group in which an acid group is anhydride, and the like, and a phenolic hydroxyl group, an amino group, or an acid group is preferably an anhydride group. It is more preferable that it is a hydroxyl group or an amino group.

Among the thermosetting agents (B2), examples of the phenolic curing agent having a phenolic hydroxyl group include polyfunctional phenol resins, biphenols, novolac phenol resins, dicyclopentadiene phenol resins, aralkyl phenol resins, and the like. I can.

Among the thermal curing agents (B2), examples of the amine curing agent having an amino group include dicyandiamide.

The thermosetting agent (B2) may have an unsaturated hydrocarbon group.

Examples of the thermosetting agent (B2) having an unsaturated hydrocarbon group include compounds obtained by substituting a part of the hydroxyl group of a phenol resin with a group having an unsaturated hydrocarbon group, and a compound obtained by directly bonding a group having an unsaturated hydrocarbon group to the aromatic ring of the phenol resin. I can.

The unsaturated hydrocarbon group in the thermosetting agent (B2) is the same as the unsaturated hydrocarbon group in the epoxy resin having the above-described unsaturated hydrocarbon group.

When a phenolic curing agent is used as the thermal curing agent (B2), it is preferable that the thermal curing agent (B2) has a high softening point or glass transition temperature from the viewpoint of improving the peelability of the protective film from the supporting sheet.

Among the thermosetting agents (B2), for example, the number average molecular weight of resin components such as polyfunctional phenol resin, novolak type phenol resin, dicyclopentadiene type phenol resin, and aralkyl type phenol resin is preferably 300 to 30000, It is more preferable that it is 400-10000, and it is especially preferable that it is 500-3000.

Among the thermosetting agents (B2), for example, the molecular weight of the non-resin component such as biphenol and dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

The thermosetting agent (B2) may be used singly or in combination of two or more, and when two or more of them are used in combination, combinations and ratios thereof can be arbitrarily selected.

In the composition (III-1) and the film for forming a thermosetting protective film, the content of the thermosetting agent (B2) is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass based on 100 parts by mass of the epoxy resin (B1). It is preferable and, for example, any one of 1 to 100 parts by mass, 1 to 50 parts by mass, 1 to 25 parts by mass, and 1 to 10 parts by mass may be used. When the content of the thermosetting agent (B2) is equal to or greater than the lower limit, the curing of the film for forming a thermosetting protective film is more likely to proceed. Further, when the content of the thermosetting agent (B2) is equal to or less than the upper limit, the moisture absorption rate of the film for forming a thermosetting protective film is reduced, and the reliability of the package obtained by using the composite sheet for forming a protective film is further improved.

The content of the thermosetting component (B) in the composition (III-1) and the film for forming a thermosetting protective film (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is the content of the polymer component (A) 100 It is preferably 20 to 500 parts by mass, more preferably 30 to 300 parts by mass, even more preferably 40 to 150 parts by mass, for example, 45 to 100 parts by mass, and 50 to 80 parts by mass, etc. Any one of them may be sufficient. When the content of the thermosetting component (B) is in such a range, for example, the adhesion between the cured product of the protective film-forming film and the support sheet is suppressed, and the peelability of the support sheet is improved.

[Hardening accelerator (C)]

The composition (III-1) and the film for forming a thermosetting protective film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of the composition (III-1).

Preferred curing accelerators (C) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5 Imidazoles such as hydroxymethylimidazole (imidazole in which at least one hydrogen atom is substituted with a group other than a hydrogen atom); Organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphine in which at least one hydrogen atom is substituted with an organic group); And tetraphenyl boron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

The composition (III-1) and the curing accelerator (C) contained in the film for forming a thermosetting protective film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

When using a curing accelerator (C), the content of the curing accelerator (C) in the composition (III-1) and the film for forming a thermosetting protective film is 0.01 to 10 parts by mass based on 100 parts by mass of the thermosetting component (B). It is preferable and it is more preferable that it is 0.1-7 mass parts. When the content of the curing accelerator (C) is more than the lower limit, the effect of using the curing accelerator (C) is more remarkably obtained. In addition, when the content of the curing accelerator (C) is less than or equal to the above upper limit, for example, the highly polar curing accelerator (C) moves to the adhesive interface side with the adherend in the film for forming a thermosetting protective film under high temperature and high humidity conditions and segregates. The effect of suppressing this increases, and the reliability of the semiconductor chip with the protective film obtained by using the composite sheet for forming a protective film is further improved.

[Filling material (D)]

The composition (III-1) and the film for forming a thermosetting protective film may contain a filler (D). When the film for forming a thermosetting protective film contains the filler (D), it becomes easier to adjust the water absorption rate and the adhesive force change rate within a target range. In addition, since the thermosetting protective film-forming film and the protective film contain a filler (D), it becomes easier to control the thermal expansion coefficient, and by optimizing the thermal expansion coefficient for the film for forming a thermosetting protective film or the object for which the protective film is to be formed, for forming a protective film The reliability of the semiconductor chip with the protective film obtained by using the composite sheet is further improved. Further, the film for forming a thermosetting protective film may contain the filler (D), thereby reducing the moisture absorption rate of the protective film or improving the heat dissipation property.

The filler (D) may be any of an organic filler and an inorganic filler, but is preferably an inorganic filler.

Preferred inorganic fillers include, for example, powders such as silica, alumina, talc, calcium carbonate, titanium white, bengala, silicon carbide and boron nitride; Beads in which these inorganic fillers are spheroidized; Surface modified products of these inorganic fillers; Single crystal fibers of these inorganic fillers; Glass fiber, etc. are mentioned.

Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

The composition (III-1) and the filler (D) contained in the film for forming a thermosetting protective film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

When using the filler (D), the ratio of the content of the filler (D) to the total content of all components other than the solvent in the composition (III-1) (that is, the content of the filler (D) of the film for forming a thermosetting protective film ) Is preferably 5 to 80% by mass, more preferably 10 to 70% by mass, and for example, any one of 20 to 65% by mass, 30 to 65% by mass, and 40 to 65% by mass, etc. do. When the content of the filler (D) is within such a range, the adjustment of the thermal expansion coefficient becomes easier, and the strength of the protective film-forming film and the protective film is further improved.

[Coupling agent (E)]

The composition (III-1) and the film for forming a thermosetting protective film may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesion and adhesion of the film for forming a thermosetting protective film to an adherend can be improved. Further, by using the coupling agent (E), the cured product (protective film) of the film for forming a thermosetting protective film does not impair heat resistance and improves water resistance.

The coupling agent (E) is preferably a compound having a functional group capable of reacting with a functional group contained in the polymer component (A), the thermosetting component (B), and the like, and more preferably a silane coupling agent.

Preferred silane coupling agents include, for example, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, and 3-glycidyloxypropyltrimethoxysilane. Cidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-( 2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3 -Ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltri Ethoxysilane, vinyl trimethoxysilane, vinyl triacetoxysilane, imidazole silane, etc. are mentioned.

The composition (III-1) and the coupling agent (E) contained in the thermosetting protective film-forming film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

When using the coupling agent (E), the content of the coupling agent (E) in the composition (III-1) and the film for forming a thermosetting protective film is 100 parts by mass of the total content of the polymer component (A) and the thermosetting component (B). It is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass. When the content of the coupling agent (E) is greater than or equal to the lower limit, the use of the coupling agent (E), such as improving the dispersibility of the filler (D) in the resin, or improving the adhesion of the film for forming a thermosetting protective film to the adherend. The effect is obtained more remarkably. In addition, when the content of the coupling agent (E) is equal to or less than the upper limit, generation of outgas is more suppressed.

[Crosslinking agent (F)]

When using a polymer component (A) having a functional group such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group capable of binding to other compounds such as acrylic resins described above, composition (III-1) ) And the film for forming a thermosetting protective film may contain a crosslinking agent (F). The crosslinking agent (F) is a component for crosslinking by bonding the functional group in the polymer component (A) with another compound, and by crosslinking in this manner, the initial adhesive force and cohesive force of the film for forming a thermosetting protective film can be adjusted.

Examples of the crosslinking agent (F) include an organic polyvalent isocyanate compound, an organic polyvalent imine compound, a metal chelate crosslinking agent (crosslinking agent having a metal chelate structure), an aziridine crosslinking agent (crosslinking agent having an aziridinyl group), and the like.

As the organic polyvalent isocyanate compound, for example, an aromatic polyvalent isocyanate compound, an aliphatic polyvalent isocyanate compound, and an alicyclic polyvalent isocyanate compound (hereinafter, these compounds may be encompassed and abbreviated as "aromatic polyvalent isocyanate compound etc." in some cases); Trimers, isocyanurates and adducts such as the above aromatic polyvalent isocyanate compounds; And a terminal isocyanate urethane prepolymer obtained by reacting the above aromatic polyvalent isocyanate compound and the like with a polyol compound. The ``adduct body'' is an aromatic polyvalent isocyanate compound, an aliphatic polyvalent isocyanate compound or an alicyclic polyvalent isocyanate compound, and a low-molecular active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil. Means reactant. Examples of the adduct body include a xylylene diisocyanate adduct of trimethylolpropane as described below. In addition, "terminal isocyanate urethane prepolymer" is as described above.

More specifically as the organic polyvalent isocyanate compound, for example, 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylene diisocyanate; Diphenylmethane-4,4'-diisocyanate; Diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; Hexamethylene diisocyanate; Isophorone diisocyanate; Dicyclohexylmethane-4,4'-diisocyanate; Dicyclohexylmethane-2,4'-diisocyanate; Compounds in which any one or two or more of tolylene diisocyanate, hexamethylene diisocyanate and xylylene diisocyanate are added to all or part of the hydroxyl groups of polyols such as trimethylolpropane; Lysine diisocyanate, etc. are mentioned.

Examples of the organic polyvalent imine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxyamide), trimethylolpropane-tri-β-aziridinylpropionate, Tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-toluene-2,4-bis(1-aziridinecarboxyamide)triethylene melamine, and the like.

When an organic polyvalent isocyanate compound is used as the crosslinking agent (F), it is preferable to use a hydroxyl group-containing polymer as the polymer component (A). When the crosslinking agent (F) has an isocyanate group and the polymer component (A) has a hydroxyl group, the crosslinking structure can be conveniently introduced into the film for forming a thermosetting protective film by reaction of the crosslinking agent (F) and the polymer component (A).

The composition (III-1) and the crosslinking agent (F) contained in the film for forming a thermosetting protective film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

When using the crosslinking agent (F), the content of the crosslinking agent (F) in the composition (III-1) is preferably 0.01 to 20 parts by mass, and 0.1 to 10 parts by mass based on 100 parts by mass of the polymer component (A). It is more preferable and it is especially preferable that it is 0.5-5 mass parts. When the content of the crosslinking agent (F) is more than the lower limit, the effect of using the crosslinking agent (F) is more remarkably obtained. Further, when the content of the crosslinking agent (F) is less than or equal to the upper limit, excessive use of the crosslinking agent (F) is suppressed.

[Energy ray curable resin (G)]

The composition (III-1) may contain an energy ray-curable resin (G). Since the film for thermosetting protective film formation contains the energy ray-curable resin (G), the characteristic can be changed by irradiation of an energy ray.

The energy ray-curable resin (G) is obtained by polymerizing (curing) an energy ray-curable compound.

Examples of the energy ray-curable compound include a compound having at least one polymerizable double bond in a molecule, and an acrylate compound having a (meth)acryloyl group is preferable.

Examples of the acrylate-based compound include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylic. Rate, dipentaerythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) ) (Meth)acrylate containing a chain aliphatic skeleton such as acrylate; Cyclic aliphatic skeleton-containing (meth)acrylates such as dicyclopentanyldi(meth)acrylate; Polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; Oligoester (meth)acrylate; Urethane (meth)acrylate oligomers; Epoxy modified (meth)acrylate; Polyether (meth)acrylate other than the polyalkylene glycol (meth)acrylate; Itaconic acid oligomer, etc. are mentioned.

It is preferable that it is 100-30000, and, as for the weight average molecular weight of the said energy ray-curable compound, it is more preferable that it is 300-10000.

The energy ray-curable compound used for polymerization may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The energy ray-curable resin (G) contained in the composition (III-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

When using an energy ray-curable resin (G), the content of the energy ray-curable resin (G) of the composition (III-1) is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, It is particularly preferably 10 to 85% by mass.

[Photopolymerization initiator (H)]

When the composition (III-1) contains an energy ray-curable resin (G), it may contain a photopolymerization initiator (H) in order to efficiently advance the polymerization reaction of the energy ray-curable resin (G).

As the photoinitiator (H) in the composition (III-1), for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin Benzoin compounds such as methyl benzoate and benzoin dimethyl ketal; Acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and 2,2-dimethoxy-1,2-diphenylethan-1-one; Acylphosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; Sulfide compounds such as benzylphenyl sulfide and tetramethylthiuram monosulfide; Α-ketol compounds such as 1-hydroxycyclohexylphenyl ketone; Azo compounds such as azobisisobutyronitrile; Titanocene compounds such as titanocene; Thioxanthone compounds such as thioxanthone; Peroxide compounds; Diketone compounds such as diacetyl; benzyl; Dibenzyl; Benzophenone; 2,4-diethyl thioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; 2-chloroanthraquinone, etc. are mentioned.

Further, examples of the photopolymerization initiator include quinone compounds such as 1-chloroanthraquinone; Photosensitizers, such as an amine, etc. are also mentioned.

The photopolymerization initiator (H) contained in the composition (III-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

When a photoinitiator (H) is used, the content of the photoinitiator (H) in the composition (III-1) is preferably 0.1 to 20 parts by mass based on 100 parts by mass of the energy ray-curable resin (G), 1 It is more preferable that it is -10 mass parts, and it is especially preferable that it is 2-5 mass parts.

[Coloring agent (I)]

The composition (III-1) and the film for forming a thermosetting protective film may contain a coloring agent (I).

As the colorant (I), well-known things, such as an inorganic pigment, an organic pigment, and an organic dye, are mentioned, for example.

The organic pigments and organic dyes include, for example, an aminium pigment, a cyanine pigment, a merocyanine pigment, a chromonium pigment, a squarylium pigment, an azrenium pigment, a polymethine pigment, a naphthoquinone pigment. , Pyryllium pigment, phthalocyanine pigment, naphthalocyanine pigment, naphtholactam pigment, azo pigment, condensed azo pigment, indigo pigment, perinone pigment, perylene pigment, dioxazine pigment, quinacridone pigment, Isoindolinone dye, quinophthalone dye, pyrrole dye, thioindigo dye, metal complex dye (metal complex dye), dithiol metal complex dye, indolephenol dye, triarylmethane dye, anthra And quinone-based dyes, dioxazine-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyrantrone-based dyes, and srene-based dyes.

Examples of the inorganic pigment include carbon black, cobalt pigment, iron pigment, chromium pigment, titanium pigment, vanadium pigment, zirconium pigment, molybdenum pigment, ruthenium pigment, platinum pigment, ITO (indium Tin oxide)-based dyes, ATO (antimony tin oxide)-based dyes, and the like.

The composition (III-1) and the colorant (I) contained in the film for forming a thermosetting protective film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

When using the colorant (I), the content of the colorant (I) in the film for forming a thermosetting protective film may be appropriately adjusted according to the purpose. For example, by adjusting the content of the colorant (I) in the film for forming a thermosetting protective film, and adjusting the light transmittance of the protective film, printing visibility when laser printing is performed on the protective film can be adjusted. Further, by adjusting the content of the colorant (I) in the film for forming a thermosetting protective film, the design properties of the protective film can be improved or it is possible to make it difficult to show the grinding traces on the back surface of the semiconductor wafer. Considering these points, the ratio of the content of the colorant (I) to the total content of all components other than the solvent in the composition (III-1) (that is, the content of the colorant (I) of the film for forming a thermosetting protective film) is 0.1 It is preferable that it is -10 mass %, it is more preferable that it is 0.1-7.5 mass %, It is especially preferable that it is 0.1-5 mass %. When the content of the coloring agent (I) is more than the lower limit, the effect of using the coloring agent (I) is more remarkably obtained. Further, when the content of the colorant (I) is equal to or less than the upper limit, excessive decrease in light transmittance of the film for forming a thermosetting protective film is suppressed.

[Universal Additive (J)]

The composition (III-1) and the film for forming a thermosetting protective film may contain a general-purpose additive (J) within a range that does not impair the effects of the present invention.

The general-purpose additive (J) may be a known one and may be arbitrarily selected according to the purpose, and is not particularly limited, but preferable examples include a plasticizer, an antistatic agent, an antioxidant, and a gettering agent.

The composition (III-1) and the general-purpose additives (J) contained in the film for forming a thermosetting protective film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The content of the composition (III-1) and the general-purpose additive (J) in the film for forming a thermosetting protective film is not particularly limited, and may be appropriately selected according to the purpose.

[menstruum]

It is preferable that the composition (III-1) further contains a solvent. The composition (III-1) containing a solvent becomes good in handleability.

The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; Alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; Esters such as ethyl acetate; Ketones such as acetone and methyl ethyl ketone; Ethers such as tetrahydrofuran; And amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone.

The solvent contained in the composition (III-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

The solvent contained in the composition (III-1) is preferably methyl ethyl ketone or the like from the viewpoint that the components contained in the composition (III-1) can be more uniformly mixed.

<<The manufacturing method of the composition for thermosetting protective film formation>>

Compositions for forming a thermosetting protective film such as composition (III-1) are obtained by blending each component for constituting the composition.

The order of addition at the time of compounding each component is not particularly limited, and two or more components may be added simultaneously.

In the case of using a solvent, it may be used by mixing the solvent with any of the components other than the solvent and diluting the component in advance, and without pre-diluting any of the components other than the solvent, You may use it by mixing with these compounding components.

The method of mixing each component at the time of mixing is not particularly limited, and a method of mixing by rotating a stirrer or a stirring blade, etc.; Mixing using a mixer; What is necessary is just to select suitably from well-known methods, such as a method of adding ultrasonic waves and mixing.

The temperature and time at the time of addition and mixing of each component are not particularly limited as long as each compounding component does not deteriorate, and may be appropriately adjusted, but the temperature is preferably 15 to 30°C.

○ Energy ray-curable protective film formation film

Examples of the film for forming an energy ray-curable protective film include those containing the energy ray-curable component (a), and preferably contain the energy ray-curable component (a) and a filler.

In the film for forming an energy ray-curable protective film, the energy ray-curable component (a) is preferably uncured, preferably having adhesiveness, and more preferably uncured and having adhesiveness. Here, "energy ray" and "energy ray curability" are as described above.

The curing conditions at the time of curing after attaching the energy ray-curable protective film-forming film to the back surface of the semiconductor wafer are not particularly limited as long as the curing degree is such that the cured product sufficiently exhibits its function, and for forming an energy ray-curable protective film It may be appropriately selected according to the type of film.

For example, it is preferable that the illuminance of the energy ray at the time of curing the energy ray-curable protective film-forming film is 120 to 280 mW/cm 2. In addition, it is preferable that the amount of light of the energy ray at the time of curing is 100 to 1000 mJ/cm 2.

<Composition for energy ray-curable protective film formation (IV-1)>

As a preferable composition for forming an energy ray-curable protective film, for example, the composition (IV-1) for forming an energy ray-curable protective film containing the energy ray-curable component (a) (in this specification, simply ``composition (IV-1) )” and may be abbreviated).

[Energy ray curable component (a)]

The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and provides film-forming properties or flexibility to the energy ray-curable protective film-forming film, and is also a component for forming a hard protective film after curing. .

Examples of the energy ray-curable component (a) include a polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80000 to 2000000, and a compound (a2) having an energy ray-curable group and a molecular weight of 100-80000. . The polymer (a1) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

(Polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80000 to 2000000)

As a polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80000 to 2000000, for example, an acrylic polymer (a11) having a functional group capable of reacting with a group of other compounds, a group reacting with the functional group, and energy ray-curable An acrylic resin (a1-1) obtained by reacting an energy ray-curable compound (a12) having an energy ray-curable group such as a double bond or the like is mentioned.

Examples of the functional groups capable of reacting with groups of other compounds include a hydroxyl group, a carboxyl group, an amino group, a substituted amino group (a group obtained by substituting one or two hydrogen atoms of the amino group with a group other than a hydrogen atom), and an epoxy group. . However, in terms of preventing corrosion of circuits such as semiconductor wafers and semiconductor chips, the functional group is preferably a group other than a carboxyl group.

Among these, it is preferable that the said functional group is a hydroxyl group.

・Acrylic polymer (a11) having a functional group

Examples of the acrylic polymer (a11) having a functional group include those obtained by copolymerizing an acrylic monomer having the functional group and an acrylic monomer having no functional group. In addition to these monomers, a monomer other than an acrylic monomer ( Non-acrylic monomer) may be copolymerized.

Further, the acrylic polymer (a11) may be a random copolymer or a block copolymer, and a known method may be employed for the polymerization method.

Examples of the acrylic monomer having a functional group include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, a substituted amino group-containing monomer, and an epoxy group-containing monomer.

Examples of the hydroxyl group-containing monomer include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and (meth)acrylate. ) (Meth)acrylate hydroxyalkyl such as 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; Non-(meth)acrylic unsaturated alcohols (unsaturated alcohols having no (meth)acryloyl skeleton), such as vinyl alcohol and allyl alcohol, may be mentioned.

Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; Ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as fumaric acid, itaconic acid, maleic acid and citraconic acid; Anhydrides of the ethylenically unsaturated dicarboxylic acids; (Meth)acrylic acid carboxyalkyl esters, such as 2-carboxyethyl methacrylate, etc. are mentioned.

The acrylic monomer having the functional group is preferably a hydroxyl group-containing monomer.

The acrylic monomers constituting the acrylic polymer (a11) and having the functional group may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof may be arbitrarily selected.

Examples of acrylic monomers having no functional group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and (meth)acrylate. )Isobutyl acrylate, (meth)acrylic acid sec-butyl, (meth) acrylate tert-butyl, (meth) acrylate pentyl, (meth) acrylate, heptyl (meth) acrylate, (meth) acrylate 2-ethylhexyl, (meth) ) Isooctyl acrylate, (meth) acrylate n-octyl, (meth) acrylate n-nonyl, (meth) acrylate isononyl, (meth) acrylate, (meth) acrylate undecyl, (meth) acrylate dodecyl (( Meth) lauryl acrylate), (meth) tridecyl acrylate, (meth) tetradecyl acrylate ((meth) myristyl acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate ((meth) palmityl acrylate) , (Meth)acrylic acid alkyl ester in which the alkyl group constituting the alkyl ester such as heptadecyl (meth)acrylate and (meth)acrylate octadecyl ((meth)acrylate stearyl) has a chain structure having 1 to 18 carbon atoms. have.

In addition, as an acrylic monomer having no functional group, for example, alkoxyalkyl groups such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate Containing (meth)acrylic acid ester; (Meth)acrylic acid esters having an aromatic group, including (meth)acrylic acid aryl esters such as phenyl (meth)acrylate; Non-crosslinkable (meth)acrylamide and derivatives thereof; And (meth)acrylic acid esters having a non-crosslinkable tertiary amino group such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

The acrylic monomer constituting the acrylic polymer (a11), which does not have a functional group, may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

Examples of the non-acrylic monomer include olefins such as ethylene and norbornene; Vinyl acetate; Styrene, etc. are mentioned.

The non-acrylic monomers constituting the acrylic polymer (a11) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof may be arbitrarily selected.

In the acrylic polymer (a11), the ratio (content) of the amount of the constituent unit derived from the acrylic monomer having the functional group to the total amount of the constituent units constituting it is preferably 0.1 to 50% by mass, and 1 to 40 It is more preferable that it is mass %, and it is especially preferable that it is 3-30 mass %. When the ratio is within such a range, the content of the energy ray-curable group in the acrylic resin (a1-1) obtained by copolymerization of the acrylic polymer (a11) and the energy ray-curable compound (a12) is the degree of curing of the protective film. Can be easily adjusted to a preferred range.

The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof may be arbitrarily selected.

The ratio of the content of the acrylic resin (a1-1) to the total content of components other than the solvent in the composition (IV-1) (that is, the content of the acrylic resin (a1-1) in the film for forming an energy ray-curable protective film) is It is preferably 1 to 70% by mass, more preferably 5 to 60% by mass, and particularly preferably 10 to 50% by mass.

Energy ray-curable compound (a12)

The energy ray-curable compound (a12) preferably has one or two or more selected from the group consisting of an isocyanate group, an epoxy group, and a carboxy group as a group capable of reacting with a functional group of the acrylic polymer (a11), and as the group It is more preferable to have an isocyanate group. When the energy ray-curable compound (a12) has, for example, an isocyanate group as the group, the isocyanate group readily reacts with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the functional group.

The energy ray-curable compound (a12) preferably has 1 to 5, and more preferably 1 to 3, the energy ray-curable groups per molecule.

Examples of the energy ray-curable compound (a12) include 2-methacryloyloxyethyl isocyanate, meth-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1- (Bisacryloyloxymethyl) ethyl isocyanate;

An acryloyl monoisocyanate compound obtained by reaction of a diisocyanate compound or a polyisocyanate compound and hydroxyethyl (meth)acrylate;

An acryloyl monoisocyanate compound obtained by reaction of a diisocyanate compound or a polyisocyanate compound, a polyol compound, and hydroxyethyl (meth)acrylate, etc. are mentioned.

Among these, the energy ray-curable compound (a12) is preferably 2-methacryloyloxyethyl isocyanate.

The energy ray-curable compound (a12) constituting the acrylic resin (a1-1) may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof may be arbitrarily selected.

The ratio of the content of the energy ray-curable group derived from the energy ray-curable compound (a12) to the content of the functional group derived from the acrylic polymer (a11) in the acrylic resin (a1-1) is 20 to 120 mol% It is preferable that it is, it is more preferable that it is 35-100 mol%, and it is especially preferable that it is 50-100 mol%. When the ratio of the content is within such a range, the adhesive strength of the protective film after curing becomes larger. On the other hand, in the case where the energy ray-curable compound (a12) is a monofunctional compound (having one group in one molecule), the upper limit of the ratio of the content is 100 mol%, but the energy ray-curable compound (a12) is In the case of a polyfunctional (having two or more of the above groups per molecule), the upper limit of the ratio of the content may exceed 100 mol%.

The weight average molecular weight (Mw) of the polymer (a1) is preferably 100000 to 2000000, more preferably 300000 to 150,000.

When the polymer (a1) is at least partially crosslinked with a crosslinking agent, the polymer (a1) does not correspond to any of the aforementioned monomers described as constituting the acrylic polymer (a11), and A monomer having a group reacting with a crosslinking agent may be polymerized and crosslinked in a group reacting with the crosslinking agent, or may be crosslinked in a group reacting with the functional group derived from the energy ray-curable compound (a12).

The polymer (a1) contained in the composition (IV-1) and the film for forming an energy ray-curable protective film may be one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

(Compound (a2) having an energy ray-curable group and a molecular weight of 100 to 800,000)

The energy ray-curable group in the compound (a2) having an energy ray-curable group having a molecular weight of 100 to 800,000 may include a group containing an energy ray-curable double bond, and preferable examples include a (meth)acryloyl group and a vinyl group. I can.

The compound (a2) is not particularly limited as long as it satisfies the above conditions, and examples thereof include a low molecular weight compound having an energy ray-curable group, an epoxy resin having an energy ray-curable group, and a phenol resin having an energy ray-curable group.

Among the compounds (a2), examples of the low molecular weight compound having an energy ray-curable group include a polyfunctional monomer or oligomer, and an acrylate compound having a (meth)acryloyl group is preferable.

Examples of the acrylate-based compound include 2-hydroxy-3-(meth)acryloyloxypropylmethacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth) Acrylate, 2,2-bis[4-((meth)acryloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxy Diethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloxypolypropoxy )Phenyl]propane, tricyclodecanedimethanoldi(meth)acrylate, 1,10-decanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, 1,9-nonandioldi (Meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, ethylene glycol di (Meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloxyethoxy)phenyl]propane, neopentyl glycol Difunctional (meth)acrylates such as di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, and 2-hydroxy-1,3-di(meth)acryloxypropane;

Tris(2-(meth)acryloxyethyl)isocyanurate, ε-caprolactone-modified tris(2-(meth)acryloxyethyl)isocyanurate, ethoxylated glycerin tri(meth)acrylate, pentaerythritol Tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, Polyfunctional (meth)acrylates such as dipentaerythritol poly(meth)acrylate and dipentaerythritol hexa(meth)acrylate;

Polyfunctional (meth)acrylate oligomers, such as a urethane (meth)acrylate oligomer, etc. are mentioned.

Among the compounds (a2), as an epoxy resin having an energy ray-curable group and a phenolic resin having an energy ray-curable group, those described in paragraph 0043 of “JP 2013-194102 A” can be used. Such a resin also corresponds to a resin constituting a thermosetting component described later, but is handled as the compound (a2) in the present invention.

It is preferable that it is 100-30000, and, as for the weight average molecular weight of the said compound (a2), it is more preferable that it is 300-10000.

The compound (a2) contained in the composition (IV-1) and the film for forming an energy ray-curable protective film may be only one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

[Polymer (b) not having an energy ray-curable group]

When the composition (IV-1) and the film for forming an energy ray-curable protective film contain the compound (a2) as the energy ray-curable component (a), a polymer (b) having no energy ray-curable group is also contained. desirable.

The polymer (b) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

Examples of the polymer (b) having no energy ray-curable group include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber resins, and acrylic urethane resins.

Among these, the polymer (b) is preferably an acrylic polymer (hereinafter sometimes abbreviated as "acrylic polymer (b-1)").

The acrylic polymer (b-1) may be a known one, for example, a homopolymer of one acrylic monomer, a copolymer of two or more acrylic monomers, or one or two or more acrylic monomers and 1 It may be a copolymer of a type or a monomer other than two or more types of acrylic monomers (non-acrylic monomers).

Examples of the acrylic monomers constituting the acrylic polymer (b-1) include (meth)acrylate alkyl ester, (meth)acrylic acid ester having a cyclic skeleton, glycidyl group-containing (meth)acrylic acid ester, and hydroxyl group-containing ( Meth)acrylic acid ester, substituted amino group-containing (meth)acrylic acid ester, and the like. Here, the "substituted amino group" is as described above.

Examples of the (meth)acrylate alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and (meth)acrylate. )Isobutyl acrylate, (meth)acrylic acid sec-butyl, (meth) acrylate tert-butyl, (meth) acrylate pentyl, (meth) acrylate, heptyl (meth) acrylate, (meth) acrylate 2-ethylhexyl, (meth) ) Isooctyl acrylate, (meth) acrylate n-octyl, (meth) acrylate n-nonyl, (meth) acrylate isononyl, (meth) acrylate, (meth) acrylate undecyl, (meth) acrylate dodecyl (( Meth) lauryl acrylate), (meth) tridecyl acrylate, (meth) tetradecyl acrylate ((meth) myristyl acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate ((meth) palmityl acrylate) , (Meth)acrylic acid alkyl ester in which the alkyl group constituting the alkyl ester such as heptadecyl (meth)acrylate and (meth)acrylate octadecyl ((meth)acrylate stearyl) has a chain structure having 1 to 18 carbon atoms. have.

Examples of the (meth)acrylic acid ester having a cyclic skeleton include (meth)acrylate cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate;

(Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate;

(Meth) acrylate cycloalkenyl ester, such as (meth) acrylate dicyclopentenyl ester;

And (meth)acrylate cycloalkenyloxyalkyl esters such as dicyclopentenyloxyethyl (meth)acrylate.

Examples of the glycidyl group-containing (meth)acrylic acid ester include glycidyl (meth)acrylate.

Examples of the hydroxyl group-containing (meth)acrylic acid ester include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxy (meth)acrylate. Propyl, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and the like are mentioned.

Examples of the substituted amino group-containing (meth)acrylate ester include N-methylaminoethyl (meth)acrylate.

Examples of the non-acrylic monomers constituting the acrylic polymer (b-1) include olefins such as ethylene and norbornene; Vinyl acetate; Styrene, etc. are mentioned.

As the polymer (b) which does not have the energy ray-curable group at least partially crosslinked with a crosslinking agent, for example, a reactive functional group in the polymer (b) reacts with a crosslinking agent.

The reactive functional group may be appropriately selected depending on the type of crosslinking agent, and the like, and is not particularly limited. For example, when the crosslinking agent is a polyisocyanate compound, examples of the reactive functional group include a hydroxyl group, a carboxyl group, and an amino group. Among these, a hydroxyl group having high reactivity with an isocyanate group is preferable. Further, when the crosslinking agent is an epoxy-based compound, examples of the reactive functional group include a carboxyl group, an amino group, and an amide group, and among these, a carboxyl group having high reactivity with an epoxy group is preferable. However, from the viewpoint of preventing corrosion of the circuit of the semiconductor wafer or the semiconductor chip, the reactive functional group is preferably a group other than a carboxyl group.

Examples of the polymer (b) having no energy ray-curable group having a reactive functional group include those obtained by polymerizing at least a monomer having the reactive functional group. In the case of the acrylic polymer (b-1), one or both of the above acrylic monomers and non-acrylic monomers used as monomers constituting it may be used as the one having the reactive functional group. Examples of the polymer (b) having a hydroxyl group as a reactive functional group include those obtained by polymerizing a hydroxyl group-containing (meth)acrylic acid ester, and in addition to this, one or two of the above acrylic monomers or non-acrylic monomers What is obtained by polymerizing a monomer obtained by substituting the above hydrogen atom with the above reactive functional group is mentioned.

In the polymer (b) having a reactive functional group, the ratio (content) of the amount of the constituent unit derived from the monomer having the reactive functional group to the total amount of the constituent units constituting it is preferably 1 to 20% by mass, and 2 It is more preferable that it is -10 mass %. When the ratio is within such a range, the degree of crosslinking in the polymer (b) becomes a more preferable range.

The weight average molecular weight (Mw) of the polymer (b) not having an energy ray-curable group is preferably from 10000 to 2000000, more preferably from 100000 to 150,000, from the viewpoint of better film forming properties of the composition (IV-1). . Here, "weight average molecular weight" is as previously described.

The composition (IV-1) and the energy ray-curable protective film-forming film contain only one type of polymer (b), which does not have an energy ray-curable group, and may be two or more types, and in the case of two or more types, combinations and ratios thereof Can be arbitrarily selected.

Examples of the composition (IV-1) include those containing either or both of the polymer (a1) and the compound (a2). In addition, when the composition (IV-1) contains the compound (a2), it is preferable to further contain a polymer (b) that does not have an energy ray-curable group, and in this case, further containing the above (a1) It is also desirable. Further, the composition (IV-1) does not contain the compound (a2), and may contain the polymer (a1) and the polymer (b) having no energy ray-curable group together.

When the composition (IV-1) contains the polymer (a1), the compound (a2) and the polymer (b) having no energy ray-curable group, the content of the compound (a2) in the composition (IV-1) is The total content of the polymer (a1) and the polymer (b) having no energy ray-curable group is preferably 10 to 400 parts by mass, and more preferably 30 to 350 parts by mass.

The ratio of the total content of the energy ray-curable component (a) and the polymer (b) not having an energy ray-curable group to the total content of components other than the solvent in the composition (IV-1) (i.e., for forming an energy ray-curable protective film The total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group) of the film is preferably 5 to 90% by mass, more preferably 10 to 80% by mass, and 20 to 70 It is particularly preferred that it is mass%. When the ratio of the content of the energy ray-curable component is within such a range, the energy ray-curable property of the film for forming an energy ray-curable protective film becomes better.

In addition to the energy ray-curable component, the composition (IV-1) may contain one or two or more selected from the group consisting of a thermosetting component, a filler, a coupling agent, a crosslinking agent, a photopolymerization initiator, a colorant, and a general-purpose additive, depending on the purpose. do.

For example, the energy ray-curable protective film-forming film formed by using the composition (IV-1) containing the energy ray-curable component and the thermosetting component improves adhesion to an adherend by heating, and this energy ray The strength of the protective film formed from the film for forming a curable protective film is also improved.

In addition, the energy ray-curable protective film-forming film formed by using the composition (IV-1) containing the energy-ray-curable component and the colorant has the same effect as when the thermosetting protective film-forming film described above contains the colorant (I). Express.

As the thermosetting component, filler, coupling agent, crosslinking agent, photopolymerization initiator, colorant and general-purpose additive in the composition (IV-1), the thermosetting component (B), the filler (D), and the like in the composition (III-1), respectively, The same things as the coupling agent (E), the crosslinking agent (F), the photoinitiator (H), the colorant (I) and the general-purpose additive (J) can be mentioned.

In the composition (IV-1), the thermosetting component, filler, coupling agent, crosslinking agent, photopolymerization initiator, colorant, and general-purpose additive may each be used singly or in combination of two or more, or two or more. If so, combinations and ratios thereof can be arbitrarily selected.

The content of the thermosetting component, filler, coupling agent, crosslinking agent, photoinitiator, colorant and general-purpose additive in the composition (IV-1) may be appropriately adjusted according to the purpose, and is not particularly limited.

The composition (IV-1) preferably further contains a solvent from the viewpoint of improving its handling properties by dilution.

The solvent contained in the composition (IV-1) includes, for example, the same solvent as the solvent in the composition (III-1) described above.

The number of solvents contained in the composition (IV-1) may be one or two or more.

<<The manufacturing method of the composition for energy ray-curable protective film formation>>

A composition for forming an energy ray-curable protective film such as composition (IV-1) is obtained by blending each component for constituting it.

The order of addition at the time of compounding each component is not particularly limited, and two or more components may be added simultaneously.

In the case of using a solvent, it may be used by mixing the solvent with any of the components other than the solvent and diluting the component in advance, and without pre-diluting any of the components other than the solvent, You may use it by mixing with these compounding components.

The method of mixing each component at the time of mixing is not particularly limited, and a method of mixing by rotating a stirrer or a stirring blade, etc.; Mixing using a mixer; What is necessary is just to select suitably from well-known methods, such as a method of adding ultrasonic waves and mixing.

The temperature and time at the time of addition and mixing of each component are not particularly limited as long as each compounding component does not deteriorate, and may be appropriately adjusted, but the temperature is preferably 15 to 30°C.

○ Film for forming a non-curable protective film

The film for forming a non-curable protective film does not show any change in properties due to curing, but in the present invention, it is assumed that the protective film is formed in a step affixed to a target location, such as the back surface of a semiconductor wafer.

As a preferable film for forming a non-curable protective film, those containing a thermoplastic resin are exemplified.

<Composition for forming a non-curable protective film (V-1)>

As the composition for forming a non-curable protective film, for example, the composition for forming a non-curable protective film (V-1) containing the thermoplastic resin (in this specification, it may be simply abbreviated as ``composition (V-1)''). ), etc.

[Thermoplastic resin]

The thermoplastic resin is not particularly limited.

More specifically, the thermoplastic resin is not curable, such as acrylic resin, polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, polystyrene, etc. as contained components of the above-described composition (III-1). The same thing as resin can be mentioned.

The thermoplastic resins contained in the composition (V-1) and the film for forming a non-curable protective film may be one type, may be two or more types, and in the case of two or more types, combinations and ratios thereof can be arbitrarily selected.

In the composition (V-1), the ratio of the content of the thermoplastic resin to the total content of components other than the solvent (that is, the content of the thermoplastic resin in the film for forming a non-curable protective film) is preferably 5 to 90% by mass, , For example, any one of 10 to 80% by mass and 20 to 70% by mass may be used.

In addition to the thermoplastic resin, the composition (V-1) may contain one or more selected from the group consisting of a filler, a coupling agent, a crosslinking agent, a colorant, and a general-purpose additive, depending on the purpose.

For example, the film for forming a non-curable protective film formed by using the composition (V-1) containing the thermoplastic resin and the colorant has the same effect as when the film for forming a thermosetting protective film described above contains the colorant (I). Manifest.

As the filler, coupling agent, crosslinking agent, colorant and general-purpose additive in the composition (V-1), the filler (D), coupling agent (E), crosslinking agent (F), and colorant in the composition (III-1), respectively. The same thing as (I) and general-purpose additive (J) is mentioned.

In the composition (V-1), the filler, coupling agent, crosslinking agent, colorant, and general-purpose additive may each be used singly or in combination of two or more, and when two or more are used in combination, a combination thereof And the ratio can be arbitrarily selected.

The content of the filler, coupling agent, crosslinking agent, colorant and general-purpose additive in the composition (V-1) may be appropriately adjusted according to the purpose, and is not particularly limited.

The composition (V-1) preferably further contains a solvent from the viewpoint of improving its handling properties by dilution.

Examples of the solvent contained in the composition (V-1) include the same solvent as the solvent in the composition (III-1) described above.

The number of solvents contained in the composition (V-1) may be one or two or more.

<<The manufacturing method of the composition for forming a non-curable protective film>>

A composition for forming a non-curable protective film such as composition (V-1) is obtained by blending each component for constituting it.

The order of addition at the time of compounding each component is not particularly limited, and two or more components may be added simultaneously.

In the case of using a solvent, it may be used by mixing the solvent with any of the components other than the solvent and diluting the component in advance, and without pre-diluting any of the components other than the solvent, You may use it by mixing with these compounding components.

The method of mixing each component at the time of mixing is not particularly limited, and a method of mixing by rotating a stirrer or a stirring blade, etc.; Mixing using a mixer; What is necessary is just to select suitably from well-known methods, such as a method of adding ultrasonic waves and mixing.

The temperature and time at the time of addition and mixing of each component are not particularly limited as long as each compounding component does not deteriorate, and may be appropriately adjusted, but the temperature is preferably 15 to 30°C.

◎Other floor

The support sheet may be provided with other layers such as the intermediate layer in addition to the base material and the pressure-sensitive adhesive layer within a range that does not impair the effects of the present invention.

In addition, the composite sheet for forming a protective film may be provided with other layers in addition to the base material, the pressure-sensitive adhesive layer and the film for forming a protective film within the range not impairing the effect of the present invention. In this case, the other layer is a support sheet The other layers may be provided, and may be disposed without direct contact with the support sheet.

The other layer may be arbitrarily selected according to the purpose, and the type is not particularly limited.

In one embodiment of the support sheet and the composite sheet for forming a protective film, for example, the pressure-sensitive adhesive layer is non-energy ray-curable, and the pressure-sensitive adhesive layer comprises at least the acrylic polymer and a crosslinking agent having a structural unit derived from an alkyl (meth)acrylate. And the content of the crosslinking agent relative to 100 parts by mass of the acrylic polymer content in the pressure-sensitive adhesive layer is 0.3 to 50 parts by mass, and the maximum height roughness (Rz) of the first surface of the substrate is 0.01 to 8 µm. Can be lifted.

In one embodiment of the support sheet and the composite sheet for forming a protective film, for example, the pressure-sensitive adhesive layer is non-energy ray-curable, and the pressure-sensitive adhesive layer comprises at least the acrylic polymer and a crosslinking agent having a structural unit derived from an alkyl (meth)acrylate. Constituent units and hydroxyl groups derived from alkyl (meth)acrylates containing, and the content of the crosslinking agent relative to 100 parts by mass of the acrylic polymer content in the pressure-sensitive adhesive layer is 0.3 to 50 parts by mass, and the acrylic polymer has 4 or more carbon atoms in the alkyl group It has a constituent unit derived from a containing monomer, and the said maximum height roughness (Rz) of the 1st surface of a base material is 0.01-8 micrometers.

In one embodiment of the support sheet and the composite sheet for forming a protective film, for example, the pressure-sensitive adhesive layer is non-energy ray-curable, and the pressure-sensitive adhesive layer comprises at least the acrylic polymer and a crosslinking agent having a structural unit derived from an alkyl (meth)acrylate. Constituent units and hydroxyl groups derived from alkyl (meth)acrylates containing, and the content of the crosslinking agent relative to 100 parts by mass of the acrylic polymer content in the pressure-sensitive adhesive layer is 0.3 to 50 parts by mass, and the acrylic polymer has 4 or more carbon atoms in the alkyl group It has a constituent unit derived from a containing monomer, and the content of the constitutional unit derived from a hydroxyl group-containing monomer in the acrylic polymer is 1 to 35% by mass relative to the total amount of the constitutional unit, and the maximum height roughness of the first side of the substrate What (Rz) is 0.01-8 micrometers is mentioned.

In one embodiment of the support sheet and the composite sheet for forming a protective film, for example, the pressure-sensitive adhesive layer is non-energy ray-curable, and the pressure-sensitive adhesive layer comprises at least the acrylic polymer and a crosslinking agent having a structural unit derived from an alkyl (meth)acrylate. Constituent units and hydroxyl groups derived from alkyl (meth)acrylates containing, and the content of the crosslinking agent relative to 100 parts by mass of the acrylic polymer content in the pressure-sensitive adhesive layer is 0.3 to 50 parts by mass, and the acrylic polymer has 4 or more carbon atoms in the alkyl group It has a constituent unit derived from a containing monomer, and the content of the constitutional unit derived from a hydroxyl group-containing monomer in the acrylic polymer is 1 to 35% by mass with respect to the total amount of the constituent unit, the crosslinking agent is an isocyanate-based crosslinking agent, and It is mentioned that the maximum height roughness Rz of the first surface is 0.01 to 8 μm.

◇Method of manufacturing composite sheet for forming a protective film

In the composite sheet for forming a protective film, for example, a substrate, an adhesive layer, and a film for forming a protective film are laminated in this order in their thickness direction to produce a laminated sheet (in this specification, ``Laminated sheet production process (1)") and a process of storing the laminated sheet while pressing in its thickness direction (in this specification, it may be referred to as a ``laminated sheet preservation process'') In the specification, it can be manufactured by "the manufacturing method (S1)" in some cases).

The method of forming each layer (substrate, pressure-sensitive adhesive layer, and film for forming a protective film) is as described above.

Hereinafter, the manufacturing method (S1) will be described in more detail for each step.

◎ Manufacturing method (S1)

<<Laminated sheet manufacturing process (1)>>

In the said laminated sheet manufacturing process (1), a laminated sheet|seat comprised by laminating a base material, an adhesive layer, and a film for protective film formation in these thickness direction in this order is produced.

In this process, for example, a laminated sheet having the same laminated structure as the composite sheet for forming a protective film of interest by laminating each of the above-described layers (substrate, pressure-sensitive adhesive layer, protective film-forming film, etc.) in a corresponding positional relationship. To produce.

On the other hand, in the present specification, the term ``laminated sheet'' means that it has the same lamination structure as the composite sheet for forming a protective film for the above purpose, and does not perform the lamination sheet preservation step unless otherwise noted. .

For example, when manufacturing a support sheet, in the case of laminating an adhesive layer on a substrate, the above-described adhesive composition may be coated on the substrate and dried as necessary.

On the other hand, for example, when a protective film-forming film is additionally laminated on the pressure-sensitive adhesive layer laminated on the substrate, it is possible to directly form the protective film-forming film by coating the protective film-forming composition on the pressure-sensitive adhesive layer. Layers other than the film for forming a protective film can also be laminated on the pressure-sensitive adhesive layer by the same method using the composition for forming this layer. In the case of forming a continuous two-layer laminated structure using any one composition as described above, it is possible to form a new layer by further coating the composition on the layer formed from the composition. However, the layer to be laminated later among these two layers is formed in advance using the composition on another release film, and the exposed side of the formed layer opposite to the side in contact with the release film is exposed to the remaining layers already formed. It is preferable to form a continuous two-layer laminated structure by bonding with the surface. At this time, it is preferable to apply the composition to the peeling-treated surface of the peeling film. The release film may be removed as necessary after formation of the laminated structure.

For example, a composite sheet for forming a protective film (a composite sheet for forming a protective film in which a support sheet is a laminate of a substrate and an adhesive layer) is prepared by laminating an adhesive layer on a substrate and a film for forming a protective film on the adhesive layer. In the case of application, the pressure-sensitive adhesive composition is coated on the substrate, and if necessary, the pressure-sensitive adhesive layer is laminated on the substrate, and a protective film-forming composition is separately applied on the release film, and if necessary, the release film is dried. A film for forming a protective film is formed on the top. And the said laminated sheet is obtained by bonding the exposed surface of this film for protective film formation with the exposed surface of the adhesive layer laminated on a base material, and laminating the film for protective film formation on the adhesive layer.

On the other hand, in the case of laminating the pressure-sensitive adhesive layer on the substrate, as described above, instead of coating the pressure-sensitive adhesive composition on the substrate, coating the pressure-sensitive adhesive composition on the release film and drying as necessary, the pressure-sensitive adhesive on the release film. A pressure-sensitive adhesive layer may be laminated on the substrate by forming a layer and bonding the exposed surface of this layer to one surface of the substrate.

In either method, the release film may be removed at an arbitrary timing after forming the target laminated structure.

Since all layers other than the base material constituting the composite sheet for forming a protective film can be formed in advance on the release film and laminated by a method of bonding to the surface of the target layer, such a process is employed as necessary. A layer may be appropriately selected to produce the laminated sheet.

For example, a composite sheet for forming a protective film is usually stored in a state in which a release film is adhered to the surface of the outermost layer (for example, a film for forming a protective film) opposite to the supporting sheet. Therefore, a composition for forming a layer constituting an outermost layer, such as a composition for forming a protective film, is applied on this release film (preferably, the peeling treatment surface thereof), and dried as necessary to form the outermost layer on the release film. A layer constituting the layer is formed, and the remaining layers are laminated on the exposed side opposite to the side in contact with the release film of this layer by any of the above-described methods, and are bonded without removing the release film. Even if it remains, the said laminated sheet is obtained.

When the composite sheet for forming a protective film includes the other layer, the step of forming the other layer may be appropriately added so that the above-described laminated sheet manufacturing process (1) may be placed at a suitable timing.

The shape of the laminated sheet produced in the laminated sheet production process (1) is not particularly limited. For example, in order to wind up in a roll shape, a preferable long laminated sheet may be produced, but a laminated sheet having a shape other than that of a long may be produced.

<<laminated sheet preservation process>>

In the laminated sheet preservation step, the laminated sheet is stored while being pressed in the thickness direction.

As a method of preserving the laminated sheet while pressing the laminated sheet in this step, for example, the long laminated sheet is wound in a roll shape, and the wound laminated sheet is left as it is, and the pressure generated by winding is applied to the laminated sheet. A method of preserving while applying to one side or both sides of the product; And a method of storing the elongated laminated sheet while applying pressure to one or both sides of the laminated sheet in an unfolded state without being wound up in a roll shape.

When winding up a long laminated sheet in a roll shape, it is preferable to wind up the laminated sheet in the longitudinal direction.

When winding up a laminated sheet, for example, the winding tension is preferably 150 to 170 N/m, the winding speed is preferably 45 to 55 m/min, and the taper rate (reduction rate) of the winding tension is 85 to 95%. It is preferable to be. By employing such winding conditions, the laminated sheet can be pressurized and stored at a more suitable pressure. Such winding conditions are particularly preferable to be applied to a laminated sheet having a thickness of 100 to 300 μm, a width of 300 to 500 mm, and a length of 40 to 60 m, but the size of the laminated sheet is not limited thereto.

The laminated sheet may be wound under normal temperature or room temperature, for example, or may be wound under the same temperature conditions as when the wound laminated sheet is stored under heat and pressure as described later.

The laminated sheet wound up in a roll shape may be stored at room temperature or at room temperature, but is preferably stored while heating. By heat-pressing storage in this way, a composite sheet for forming a protective film is obtained, which is superior in the lamination property of the pressure-sensitive adhesive layer and the film for forming a protective film, and more excellent in printing visibility through the supporting sheet of the protective film or the film for forming a protective film.

When the laminated sheet is wound in a roll shape, the heating temperature at the time of storage is not particularly limited, but it is preferably 53 to 75°C, more preferably 55 to 70°C, and particularly preferably 57 to 65°C.

The storage time when the laminated sheet is wound up in a roll shape is not particularly limited, but is preferably 24 to 720 hours (1 to 30 days), more preferably 48 to 480 hours (2 to 20 days), and 72 to It is particularly preferred that it is 240 hours (3-10 days).

In a laminated sheet wound in a roll shape, for example, a protective film-forming film and a support sheet are processed into a specific shape, and a plurality of laminates of the support sheet and the protective film-forming film thus processed are formed on the side of the film for forming a protective film. WHEREIN: While being pasted to a long release film, what is arrange|positioned by aligning in the longitudinal direction of this release film may be sufficient. It is preferable that the film for protective film formation in this case has the same or substantially the same planar shape (usually a circular shape) as the semiconductor wafer. In addition, it is preferable that the support sheet in this case has the same or substantially the same outer periphery shape as the jig for fixing the support sheet in the dicing device. In this case, it is preferable that a strip-shaped sheet is formed in the vicinity of the periphery in the width direction among the bonding surfaces of the laminate of the release film so as not to overlap the laminate. This sheet is for suppressing the occurrence of a step (in this specification, it may be referred to as "lamination trace") on the surface of the laminate when the laminated sheet is wound in a roll shape. The lamination trace is that the lamination position of the laminate (the laminate of the processed support sheet and the protective film forming film) in the roll of the laminate sheet does not coincide in the radial direction of the roll, so that a high pressure is applied to the surface of the laminate. It is caused by burden. When the sheet is formed in the vicinity of the periphery, such high pressure is not applied to the surface of the laminate, and generation of the lamination trace is suppressed.

In the case where the elongate laminated sheet is not wound in a roll shape and is in an unfolded state, and when the laminated sheet is not long, it is preferable to further laminate and store a plurality of these laminated sheets. And, in the case of laminating the laminated sheets in this way, it is preferable that the directions of the plurality of laminated sheets and the position of the periphery are aligned with each other.

The shape and size of the non-long laminated sheet (that is, the single-leaf laminated sheet) are not particularly limited. For example, the shape of the laminated sheet according to the shape and size of the semiconductor wafer and the shape and size of the jig for fixing the supporting sheet in the dicing device so as to be suitable for processing a single semiconductor wafer using a dicing device. And it is preferable that the size is adjusted.

The laminated sheet in a laminated state may be stored at room temperature or at room temperature, but is preferably stored while heating. By heat-pressing storage in this way, a composite sheet for forming a protective film is obtained, which is superior in the lamination property of the pressure-sensitive adhesive layer and the film for forming a protective film, and more excellent in printing visibility through the supporting sheet of the protective film or the film for forming a protective film.

In addition, both the heating temperature and storage time in the case of pressurized storage of the laminated sheet in a laminated state can be the same as in the case of winding the laminated sheet in a roll shape.

In the manufacturing method (S1), by releasing the pressure of the laminated sheet and heating as necessary after the completion of the laminated sheet preservation step, the target composite sheet for forming a protective film is obtained.

In the lamination sheet manufacturing process (1) of the manufacturing method (S1), the order of lamination (bonding) of the substrate, the pressure-sensitive adhesive layer, and the protective film-forming film is not particularly limited, but a supporting sheet is prepared in advance (adhesive on the substrate in advance). Layer) to prepare a protective film-forming film in advance, and in the case of laminating the protective film-forming film on the support sheet, either or both of the support sheet and the protective film-forming film are alone, before laminating them. You may pressurize and store in the same manner as in the case of the laminated sheet described above. By individually pressurizing the support sheet before lamination, it is possible to more effectively suppress the occurrence of the non-bonded region between the substrate and the pressure-sensitive adhesive layer. In addition, by separately pressing and storing the protective film-forming film before lamination, the unevenness of the protective film-forming film and the pressure-sensitive adhesive layer side (second surface) of the protective film is reduced (the smoothness increases), and the protective film-forming film and the protective film are The design is improved.

That is, the composite sheet for forming a protective film is, for example, by laminating a film for forming a protective film on the pressure-sensitive adhesive layer of a support sheet in which a substrate and an adhesive layer are laminated, so that the substrate, the pressure-sensitive adhesive layer, and the film for forming a protective film are in this order. The process of producing a laminated sheet formed by being laminated in the thickness direction of (in this specification, it may be referred to as ``laminated sheet production process (2)''), and storing the laminated sheet while pressing it in the thickness direction A process of having a process (storing process), and preserving one or both of the support sheet and the film for forming a protective film before the laminated sheet production process (2) while pressing in the thickness direction (in this specification, the support sheet is The process of preserving is called "support sheet preservation process", and the process of preserving the film for protective film formation is sometimes called "film preservation process for protective film formation"), further comprising a manufacturing method (in this specification, ``production It can be manufactured by a method (S2)" in some cases).

◎Manufacturing method (S2)

The manufacturing method (S2) is performed by performing the lamination sheet manufacturing step (2) as the lamination sheet manufacturing step (1) described above, and adding either or both of the supporting sheet storage step and the film storage step for forming a protective film. Except for the point, it is the same as the manufacturing method (S1) described above.

<<Laminated sheet manufacturing process (2)>>

In the laminated sheet manufacturing process (2), as described above, a support sheet is prepared in advance, a protective film-forming film is prepared in advance, and a protective film-forming film is laminated on the support sheet. Except for a limited point, it is the same as the laminated sheet production process (1) in the production method (S1).

<<support sheet preservation process, film preservation process for protective film formation>>

The support sheet preservation step and the protective film-forming film preservation step can be performed in the same manner as the laminated sheet preservation step in the manufacturing method (S1), except that the object to be stored is not a laminated sheet but a support sheet or a film for protective film formation. have.

In this case, for example, the storage time of the supporting sheet and the film for forming a protective film is 24 to 720 hours (1 to 30 days), 48 to 480 hours (2 to 20 days), and 72 to 240 as in the case of the laminated sheet. Any one of time (3-10 days) may be sufficient.

On the other hand, the support sheet preservation process and the film preservation process for forming a protective film are each added to change the storage object as described above, and also change the storage time of the storage object (support sheet or film for forming a protective film), and these Except for the change point, you may perform similarly to the laminated sheet preservation process in manufacturing method (S1).

In this case, for example, the storage time of the supporting sheet and the film for forming a protective film is 12 to 720 hours (0.5 to 30 days), 12 to 480 hours (0.5 to 20 days), and 12 to 240 hours (0.5 to 10 days). Any one of them may be sufficient. However, this is an example of the storage time.

Example

Hereinafter, the present invention will be described in more detail by specific examples. However, the present invention is not at all limited to the examples shown below.

<Materials for manufacturing the composition for forming a protective film>

The raw materials used for producing the composition for forming a protective film are shown below.

Polymer component (A)

(A)-1: Acrylic polymer obtained by copolymerizing methyl acrylate (85 parts by mass) and 2-hydroxyethyl acrylate (15 parts by mass) (weight average molecular weight of 370000, glass transition temperature of 6°C)

· Thermosetting component (B1)

(B1)-1: Bisphenol A type epoxy resin (Mitsubishi Chemical Co., Ltd. "jER828", epoxy equivalent 184 to 194 g/eq)

(B1)-2: Bisphenol A type epoxy resin (Mitsubishi Chemical Co., Ltd. "jER1055", epoxy equivalent 800 to 900 g/eq)

(B1)-3: Dicyclopentadiene type epoxy resin ("Epiclon HP-7200HH" manufactured by DIC Corporation, epoxy equivalent 255 to 260 g/eq)

·Heat curing agent (B2)

(B2)-1: Dicyandiamide ("Adeka Hardener EH-3636AS" manufactured by ADEKA, a thermally active latent epoxy resin curing agent, active hydrogen content 21 g/eq)

·Hardening accelerator (C)

(C)-1: 2-phenyl-4,5-dihydroxymethylimidazole (Shikoku Chemical Industry Co., Ltd. "Qazole 2PHZ-PW")

·Filling material (D)

(D)-1: Silica filler ("SC2050MA" manufactured by Admatex, a silica filler surface-modified with an epoxy compound, average particle diameter 0.5 µm)

·Coupling agent (E)

(E)-1:3-aminopropyltrimethoxysilane ("A-1110" manufactured by NUC)

・Coloring agent (I)

(I)-1: Black pigment (manufactured by Dainichi Chemical Co., Ltd.)

[Example 1]

<Manufacture of support sheet>

(Preparation of adhesive composition (I-4))

An acrylic polymer (100 parts by mass, solid content), and a trifunctional xylylene diisocyanate crosslinking agent (``Takenate D110N'' manufactured by Takeda Chemical Co., Ltd.) (40 parts by mass (solid content)) are contained, and methyl ethyl ketone as a solvent , A non-energy ray-curable pressure-sensitive adhesive composition (I-4) containing a mixed solvent of toluene and ethyl acetate and having a solid content concentration of 30% by mass was prepared. The acrylic polymer is a precopolymer having a weight average molecular weight of 800000 obtained by copolymerizing 2-ethylhexyl acrylate (2EHA) (80 parts by mass) and 2-hydroxyethyl acrylate (HEA) (20 parts by mass).

(Manufacture of support sheet)

The pressure-sensitive adhesive composition (I-4) obtained above on the peeling-treated surface using a release film ("SP-PET381031" manufactured by Lintec Co., Ltd., thickness 38 µm) in which one side of a polyethylene terephthalate film was peeled off by a silicone treatment. Was applied and heated and dried at 120° C. for 2 minutes to form a non-energy ray-curable pressure-sensitive adhesive layer. At this time, conditions were set so that the thickness of an adhesive layer might be 4 micrometers, and the adhesive composition (I-4) was coated.

Substrate in which one surface of a polypropylene film (manufactured by Mitsubishi Resin Co., Ltd., thickness of 80 μm) is rotated and pressed while heating the uneven surface of a metal roll, so that one surface is an uneven surface and the other is a smooth surface (glossy surface) Produced. About the uneven surface of this base material, the maximum height roughness (Rz) was measured according to JIS B 0601:2013, and it was 5 micrometers.

Subsequently, by bonding the uneven surface of the substrate to the exposed surface of the pressure-sensitive adhesive layer obtained above, a support sheet formed by laminating the substrate, the pressure-sensitive adhesive layer, and the release film in the thickness direction thereof in this order was obtained. The width of the obtained supporting sheet (that is, the width of the substrate and the pressure-sensitive adhesive layer) was 400 mm.

By the above, the support sheet of the present invention was obtained.

Subsequently, for this support sheet, immediately, an evaluation of the non-bonded region between the substrate and the pressure-sensitive adhesive layer described later was performed. Moreover, this support sheet was used in the manufacture of the composite sheet for protective film formation mentioned later in that state.

<Production of composite sheet for protective film formation>

(Preparation of protective film-forming composition (III-1))

Polymer component ((A)-1) (150 parts by mass), thermosetting component ((B1)-1) (60 parts by mass), ((B1)-2) (10 parts by mass), ((B1)-3) (30 parts by mass), ((B2)-1) (2 parts by mass), curing accelerator ((C)-1) (2 parts by mass), filler ((D)-1) (320 parts by mass), coupling agent ((E)-1) (2 parts by mass), and colorant ((I)-1) (18 parts by mass) were dissolved or dispersed in a mixed solvent of methyl ethyl ketone, toluene and ethyl acetate, and stirred at 23°C. , A composition for forming a thermosetting protective film (III-1) having a solid content concentration of 51% by mass was obtained. On the other hand, all the blending amounts shown here are solid content.

(Production of protective film formation film)

A release film (2nd release film, "SP-PET381031" manufactured by Lintec, 38 µm in thickness), in which one side of the polyethylene terephthalate film was peeled off by silicone treatment, was used, and a knife coater was used for the release treatment surface. Then, the composition for forming a protective film (III-1) obtained above was applied and dried at 100° C. for 2 minutes to prepare a film for forming a thermosetting protective film having a thickness of 25 μm.

In addition, by bonding the peeling-treated surface of the peeling film (1st peeling film, "SP-PET381031" manufactured by Lintec, 38 µm in thickness) to the exposed surface of the obtained protective film forming film on the side not provided with the second release film. , A laminated film provided with a first release film on one side of the film for forming a protective film, and a second release film on the other side was obtained. The width of the obtained laminated film (in other words, the width of the film for forming a protective film, the first release film, and the second release film) was 400 mm.

(Production of composite sheet for forming a protective film)

One set (two) rolls of 5 cm in diameter and consisting of heat-resistant silicone rubber having a hardness of 50 degrees in a region of a depth of 3 mm from the surface thereof were prepared.

The release film was removed from the pressure-sensitive adhesive layer of the support sheet obtained above. Moreover, the 1st peeling film was removed from the laminated film obtained above.

In addition, the exposed surface of the pressure-sensitive adhesive layer formed by removing the release film and the exposed surface of the protective film-forming film formed by removing the first release film are made to face each other, and these support sheets and the film for forming a protective film are overlapped and laminated. While using water, the laminate was heated and pressurized (heat laminated) at a pressure of 0.5 MPa by passing through the gap between these rolls set at a temperature of 60°C at a speed of 0.3 m/min. Thereby, a laminated sheet having the same laminated structure as the composite sheet for forming a target protective film, which is constituted by stacking the base material, the pressure-sensitive adhesive layer, the film for forming a protective film, and the second release film in this order in their thickness direction (before preservation Composite sheet for forming a protective film) was produced.

In the obtained laminated sheet, the width (that is, the width of the support sheet) was 400 mm, and the outer diameter of the film for forming a protective film was 330 mm.

Next, the total size of the laminated sheet obtained above is 400 mm x 50 m, the length direction is the winding direction, and the winding tension is 160 N/m, the winding speed is 50 m/min, and the taper rate of the winding tension is 90%. It was wound around the core and wound up in a roll shape. At this time, the substrate was made to face outward in the radial direction of the roll (that is, the second release film was brought into contact with the core), and the laminated sheet was wound up.

Subsequently, this roll-shaped laminated sheet was left standing for 7 days (168 hours) under a temperature condition of 60°C in an air atmosphere.

By the above, the composite sheet for forming a protective film of the present invention having the structure shown in Fig. 2 was obtained.

Next, the following items were evaluated for the composite sheet for forming a protective film of the present invention after storage under such heating and pressurizing conditions was completed.

<Evaluation of supporting sheet and composite sheet for forming protective film>

(Measurement of the thickness of the adhesive layer)

A test piece having a size of 3 mm x 3 mm was cut out from five locations of the composite sheet for forming a protective film obtained above. The cutout positions of these five places were one location corresponding to the center of the circular protective film-forming film, and a portion near the periphery, and were set to four locations roughly corresponding to the position of a point object with respect to the center. Of these five cutout positions, the distance between the centers of one location corresponding to the center and the other four locations in the vicinity of the periphery was 100 mm.

Using a single-sided sample preparation device ("Cross Section Polisher SM-09010" manufactured by JEOL), the conditions of the intermittent shutter are set to "in" 10 seconds and "out" 5 seconds, the voltage of the ion source is 3 kV, and the total polish The time was set to 24 hours, and the cross section was formed from the test piece. The newly formed cross section was only one side per test piece.

Using a scanning electron microscope (SEM), the newly formed cross section of these five test pieces was observed, and for each test piece, the minimum value and the maximum value of the thickness of an adhesive layer were calculated|required. The observation area of the cross section of the test piece at this time was set to a 1 mm area in the width direction of the cross section.

And the average value of these minimum values was adopted as the S value of the adhesive layer, and the average value of these maximum values was adopted as the L value of the adhesive layer. Table 1 shows the results.

(Evaluation of lamination property of adhesive layer and film for protective film formation)

The composite sheet for protective film formation obtained above is irradiated with light from the outside of the substrate side, and the presence or absence of a non-bonded region between the pressure-sensitive adhesive layer and the film for forming a protective film is visually examined from the outside of the substrate side through the support sheet. Confirmed with. At this time, visual confirmation was performed over the entire area of the protective film-forming film formation region in the protective film-forming composite sheet.

And the degree of lamination of the pressure-sensitive adhesive layer and the film for forming a protective film was evaluated according to the following criteria. Table 1 shows the results.

A: There is no non-bonding area at all.

B: There is a non-bonding area, but the number is 3 or less.

C: There are 4 or more non-bonding areas.

(Evaluation of print visibility of protective film)

The second release film was removed from the composite sheet for forming a protective film obtained above, and the exposed surface (the surface opposite to the side of the adhesive layer) of the film for forming a protective film thus formed was affixed to the back surface of an 8-inch semiconductor wafer. The affixing at this time was performed using a tape mounter ("RAD2700" manufactured by Lintec). Thereby, a 1st laminated structure comprised by laminating a base material, an adhesive layer, a film for protective film formation, and a semiconductor wafer in these thickness direction in this order was produced.

Subsequently, printing was performed by irradiating laser light through a support sheet on the pressure-sensitive adhesive layer side surface (second surface) of the film for forming a protective film in the first laminated structure using a laser printing device ("CSM300M" manufactured by EO Technics). . At this time, characters having a size of 0.3 mm x 0.2 mm were printed.

Next, the printing (laser printing) of this film for forming a protective film was visually observed through a support sheet, and the visibility of the printing (character) was evaluated according to the following criteria. Table 1 shows the results. The printing visibility of the film for forming a protective film evaluated here can be considered to be equivalent to the printing visibility of the protective film.

A: The print is clear and can be easily recognized.

B: The factor is slightly hazy and cannot be easily recognized.

C: The argument is unclear and cannot be recognized.

Subsequently, the support sheet (substrate and pressure-sensitive adhesive layer) was peeled from this film for forming a protective film. And the thickness of the line of the print (character) formed in the film for protective film formation was measured using an optical microscope (made by Keyence Corporation). As a result, the thickness of the line was 40 µm or more, and it was clearly printed.

(Presence or absence of a non-bonded region between the substrate and the pressure-sensitive adhesive layer, and evaluation of the interlayer distance)

Using a scanning electron microscope (SEM, "VE-9700" manufactured by Keyence Corporation), the presence or absence of a non-bonded region between the substrate and the pressure-sensitive adhesive layer was confirmed with respect to the composite sheet for forming a protective film obtained above. And when there was a non-bonding area, the interlayer distance was measured. The confirmation and measurement at this time were performed over the entire substrate and the pressure-sensitive adhesive layer.

On the other hand, when measuring this interlayer distance, a cross section was formed in the composite sheet for forming a protective film in the same manner as in the case of the above-described test piece, and the interlayer distance between the substrate and the pressure-sensitive adhesive layer was measured in this cross section.

And according to the following criteria, evaluation regarding the non-bonding area|region between a base material and an adhesive layer was performed. Table 1 shows the results.

A: There is no non-bonding area at all.

B: There is a non-bonded region, but the interlayer distance is 0.5 µm or less.

C: There is a non-bonding area, and the interlayer distance is greater than 0.5 µm.

(Presence or absence of a non-bonded region between the adhesive layer and the film for forming a protective film, and evaluation of the interlayer distance)

At the time of evaluation regarding the non-bonded region between the above-described substrate and the pressure-sensitive adhesive layer, the presence or absence of the non-bonded region between the pressure-sensitive adhesive layer and the film for forming a protective film was simultaneously confirmed. And when there was a non-bonding area, the interlayer distance was measured. The confirmation and measurement at this time were performed over the entire area of the film for protective film formation in the composite sheet for protective film formation.

On the other hand, in the case of measuring this interlayer distance, a cross section was formed in the composite sheet for forming a protective film in the same manner as in the case of the above-described test piece, and the interlayer distance between the pressure-sensitive adhesive layer and the film for forming a protective film was measured in this cross section. .

And according to the following criteria, evaluation about the non-bonding area|region between the adhesive layer and the film for protective film formation was performed. Table 1 shows the results.

A: There is no non-bonding area at all.

B: There is a non-bonded region, but the interlayer distance is 0.5 µm or less.

C: There is a non-bonding area, and the interlayer distance is greater than 0.5 µm.

(Evaluation of the unevenness of the second surface of the film for forming a protective film)

The second release film was removed from the composite sheet for forming a protective film obtained above, and the exposed surface (the side opposite to the side of the adhesive layer, the first surface) of the film for forming a protective film thus formed was an 8-inch semiconductor wafer (200 μm thick). It was attached to the back side of. The affixing at this time was performed using a tape mounter ("RAD2700" made by Lintec). Thereby, a 1st laminated structure comprised by laminating a base material, an adhesive layer, a film for protective film formation, and a semiconductor wafer in these thickness direction in this order was produced.

Next, in the film for protective film formation after affixing to this semiconductor wafer, the state of the pressure-sensitive adhesive layer side surface (second surface) was visually confirmed through a support sheet, and evaluated according to the following criteria. Table 1 shows the results.

The degree of unevenness on the second surface of the protective film-forming film evaluated here can be considered to be equivalent to the degree of unevenness on the surface (second surface) of the protective film opposite to the semiconductor wafer side.

A: It is smooth or the degree of unevenness is very small, and the appearance of the film for forming a protective film is not impaired.

B: There is non-uniformity in some parts and it is not smooth, but the unevenness is very small, and the appearance of the film for protective film formation is not impaired.

C: The unevenness is large, and the external appearance of the film for protective film formation is impaired.

<Production of supporting sheet and composite sheet for forming protective film, and evaluation of supporting sheet and composite sheet for forming protective film>

[Example 2]

The conditions were set so that the thickness of the pressure-sensitive adhesive layer was 5 μm instead of 4 μm, except that the pressure-sensitive adhesive composition (I-4) was applied, and a support sheet was prepared and evaluated in the same manner as in Example 1.

In addition, except for using such a supporting sheet, a composite sheet for forming a protective film was produced and evaluated in the same manner as in the case of Example 1.

Table 1 shows the results.

[Example 3]

The conditions were set so that the thickness of the pressure-sensitive adhesive layer was 6 μm instead of 4 μm, and a support sheet was prepared and evaluated in the same manner as in Example 1, except that the pressure-sensitive adhesive composition (I-4) was coated.

In addition, except for using such a supporting sheet, a composite sheet for forming a protective film was produced and evaluated in the same manner as in the case of Example 1.

Table 1 shows the results.

[Comparative Example 1]

The conditions were set so that the thickness of the pressure-sensitive adhesive layer was 3 μm instead of 4 μm, except that the pressure-sensitive adhesive composition (I-4) was coated, and a support sheet was prepared and evaluated in the same manner as in Example 1.

In addition, except for using such a supporting sheet, a composite sheet for forming a protective film was produced and evaluated in the same manner as in the case of Example 1.

Table 1 shows the results.

[Comparative Example 2]

Substrate in which one surface of a polypropylene film (manufactured by Mitsubishi Resin Co., Ltd., thickness of 80 μm) is rotated and pressed while heating the uneven surface of a metal roll, so that one surface is an uneven surface and the other is a smooth surface (glossy surface) Produced. The uneven surface of the metal roll used at this time was larger than the uneven surface of the metal roll used in Example 1. About the uneven surface of the obtained base material, the maximum height roughness (Rz) was measured according to JIS B 0601:2013, and it was 8 micrometers.

A support sheet in the same manner as in Example 1, except that the substrate obtained above was used and the pressure-sensitive adhesive composition (I-4) was applied by setting conditions so that the thickness of the pressure-sensitive adhesive layer was 7 μm instead of 4 μm. Was prepared and evaluated.

In addition, except for using such a supporting sheet, a composite sheet for forming a protective film was produced and evaluated in the same manner as in the case of Example 1.

Table 1 shows the results.

As apparent from the above results, in Examples 1 to 3, the S value of the pressure-sensitive adhesive layer was 2 μm or more (2 to 4 μm), and the lamination property of the pressure-sensitive adhesive layer and the film for forming a protective film was particularly excellent. In addition, in these examples, the L value of the pressure-sensitive adhesive layer was 8 µm or less (6 to 8 µm), and the printing visibility of the protective film (film for forming a protective film) was particularly excellent.

In contrast, in Comparative Example 1, the S value of the pressure-sensitive adhesive layer was 1 μm, and there was a very thin area in the pressure-sensitive adhesive layer. For this reason, a large number of non-bonded regions existed between the pressure-sensitive adhesive layer and the film for protective film formation, and the lamination property of the pressure-sensitive adhesive layer and the film for protective film formation was poor. In addition, the presence of the non-bonding region in this manner also resulted in poor printing visibility of the protective film (film for forming a protective film) through the support sheet.

In addition, in Comparative Example 2, the L value of the pressure-sensitive adhesive layer was 10 μm, and the pressure-sensitive adhesive layer had a very thick area. For this reason, the printing visibility of the protective film (film for protective film formation) through the support sheet was poor.

On the other hand, in Examples 1 to 3, in any of the non-bonding regions between the substrate and the pressure-sensitive adhesive layer, or between the pressure-sensitive adhesive layer and the protective film-forming film, the interlayer distance is small, even if there is no, and the composite sheet for forming a protective film is It had good characteristics.

In addition, in Examples 1 to 3, the degree of unevenness on the second surface of the film for forming a protective film was small, and the film for forming a protective film was excellent in appearance, and a protective film having high designability could be formed.

The present invention can be used to manufacture a semiconductor device.

1A, 1B, 1C... Composite sheet for forming a protective film, 10... Support sheet, 10a... Film side surface (first surface) for forming a protective film of the supporting sheet, 11... Substrate, 11a... The side of the pressure-sensitive adhesive layer of the substrate (the first surface, the uneven surface), 12... Adhesive layer, 12a... The side opposite to the substrate side of the pressure-sensitive adhesive layer (first side), 12b... Side of the substrate side (the second side) of the pressure-sensitive adhesive layer, 13, 23... Film for forming a protective film, 13b... Pressure-sensitive adhesive layer side surface (second surface) of the film for forming a protective film, T _a ... The thickness of the pressure-sensitive adhesive layer, T _a1 . Minimum value of the thickness of the pressure-sensitive adhesive layer, T _a2 . Maximum value of the thickness of the adhesive layer

Claims (3)

As a support sheet having a substrate and having an adhesive layer on the substrate,
The pressure-sensitive adhesive layer side surface of the substrate is an uneven surface,
When a test piece was cut out from five places of the support sheet, and the minimum and maximum values of the thickness of the pressure-sensitive adhesive layer were obtained for each of these five test pieces, the average value of the minimum value was 1.5 μm or more, and the average value of the maximum value was 9 μm. The following support sheet. The method of claim 1,
The support sheet in which the pressure-sensitive adhesive layer is in direct contact with the uneven surface of the substrate. A composite sheet for forming a protective film, comprising a film for forming a protective film on the pressure-sensitive adhesive layer in the support sheet according to claim 1 or 2.

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