JPWO2017149890A1 - Composite sheet for protective film formation - Google Patents

Abstract

This protective film-forming composite sheet includes a support sheet, and includes a protective film-forming film on one surface of the support sheet, and the side of the support sheet opposite to the side provided with the protective film-forming film. A surface having a coating layer on the surface, and the surface roughness Ra of the surface of the coating layer opposite to the side in contact with the support sheet is the surface of the support sheet on the side having the coating layer Is smaller than the surface roughness Ra.

Description

The present invention relates to a composite sheet for forming a protective film for forming a protective film on the back surface of a semiconductor chip.
This application claims priority on March 4, 2016 based on Japanese Patent Application No. 2006-042689 for which it applied to Japan, and uses the content here.

  In recent years, semiconductor devices have been manufactured using a so-called face-down mounting method. 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 a substrate. For this reason, the back surface opposite to the circuit surface of the chip may be exposed.

  A resin film made of an organic material is formed as a protective film on the exposed back surface of the chip and may be taken into the semiconductor device as a semiconductor chip with a protective film. The protective film is used to prevent cracks from occurring in the chip after the dicing process or packaging.

  For the formation of such a protective film, a protective film-forming composite sheet comprising a protective film-forming film on a support sheet is used. As the support sheet, for example, a resin base material or a laminated structure such as a base material and an adhesive layer is used, and a laminated surface such as a protective film forming film or an adhesive layer of the base material is surface-treated. Sometimes it is done. In the protective film-forming composite sheet, in addition to the protective film-forming film having a protective film-forming ability, the support sheet can function as a dicing sheet, and the protective film-forming film and the dicing sheet are integrated. It can be made.

  In the said base material before the process used for a support sheet, the single side | surface or both surfaces have uneven | corrugated shape normally. This is because if the substrate does not have such an uneven shape, the contact surface between the substrates adheres and blocks when the substrate is wound up to form a roll, making it difficult to use. . If at least one of the contact surfaces of the substrates has an uneven shape, the area of the contact surface is reduced, so that blocking is suppressed.

  A conventional protective film-forming composite sheet using a substrate having such an uneven surface typically has a structure as shown in FIG. FIG. 4 is a cross-sectional view schematically showing an example of a conventional composite sheet for forming a protective film. Note that, in the drawings used in the following description, for example, in order to make the characteristics of the protective film-forming composite sheet easier to understand, there are cases where the main part is shown enlarged for convenience. The dimensional ratio and the like are not necessarily the same as actual.

  The conventional protective film-forming composite sheet 9 shown here includes a protective film-forming film 13 on a support sheet 90, and the support sheet 90 is made of a laminated structure of a base material 91 and an adhesive layer 12. A protective film-forming film 13 is provided on the agent layer 12. The protective film-forming film 13 becomes a protective film by curing. The protective film-forming composite sheet 9 further includes a release film 15 on the protective film-forming film 13, and the release film 15 is removed when the protective film-forming composite sheet 9 is used. In the protective film forming composite sheet 9, the surface (back surface) 90 b opposite to the surface (front surface) 90 a provided with the protective film forming film 13 of the support sheet 90, that is, the adhesive layer 12 of the substrate 91 is formed. A surface (back surface) 91b opposite to the provided surface (front surface) 91a is an uneven surface. Thus, when the back surface 91b of the base material 91 becomes an uneven surface, the composite sheet 9 for protective film formation is suppressed when it rolls up and uses it as a roll. That is, adhesion between the laminated protective film-forming composite sheets 9, more specifically, adhesion between the back surface 91 b of the substrate 91 and the exposed surface (front surface) 15 a of the release film 15 is suppressed.

  On the other hand, the composite sheet for protective film formation is printed on the surface of the protective film formed from the protective film-forming film on the support sheet side by irradiation with laser light (hereinafter sometimes referred to as “laser printing”). Sometimes done. Laser printing is applied from the opposite side of the support sheet on which the protective film is formed. At this time, for example, in the case of the composite sheet 9 for forming the protective film, the protective film is irradiated with laser light from the back surface 91b side of the base material 91 through the support sheet 90. Since it is an uneven surface, there is a problem that light is irregularly reflected here and laser printing becomes unclear.

  As a protective sheet-forming composite sheet capable of preventing such irregular reflection of light, a protective film-forming composite sheet 8 having a configuration as shown in FIG. 5 is known (for example, see Patent Document 1). FIG. 5 is a cross-sectional view schematically showing another example of a conventional composite sheet for forming a protective film.

  The conventional protective film-forming composite sheet 8 shown here is provided with the protective film-forming film 13 on the support sheet 80, similarly to the protective film-forming composite sheet 9. It consists of the laminated structure of the agent layer 12, and is provided with the film 13 for protective film formation on the adhesive layer 12. FIG. However, in the support sheet 80, the arrangement of the uneven surface of the base material 81 is opposite to that of the base material 91 in the support sheet 90. That is, in the composite sheet 8 for forming the protective film, the surface (front surface) 81a of the base material 81 provided with the adhesive layer 12 is an uneven surface, and the surface (back surface) opposite to the surface 81a of the base material 81. ) 81b is a smooth surface. The base material 81, the protective film forming film 13 and the release film 15 in the support sheet 80 are the same as the base material 91, the protective film forming film 13 and the release film 15 in the support sheet 90, respectively.

However, in the case of the composite sheet 8 for forming a protective film, the back surface 81b of the substrate 81, that is, the surface (back surface) 80b opposite to the surface (front surface) 80a provided with the adhesive layer 12 of the support sheet 80. Is a smooth surface, and when the protective film-forming composite sheet 8 is wound up into a roll, sticking between the back surface 81b of the substrate 81 and the exposed surface (front surface) 15a of the release film 15, that is, blocking is performed. It cannot be suppressed. When blocking occurs, wrinkles occur in the protective film-forming composite sheet 8, or the release film 15 peels off from the protective film-forming film 13 when the protective film-forming composite sheet 8 is unwound from the roll. Furthermore, on the surface 81a of the base material 81, the pressure-sensitive adhesive layer 12 needs to have a sufficient thickness so as to eliminate the uneven shape. If this is insufficient, the surface (back surface) 13b on the support sheet 80 side of the protective film forming film 13 will have an uneven shape reflecting the uneven shape of the base material 81, and such a protective film formation will be performed. There was a problem that the laser printing applied to the surface on the support sheet side of the protective film formed from the protective film 13 became unclear.
Thus, conventionally, there has been no actual situation in which there is no composite sheet for forming a protective film that can achieve both blocking suppression and clear laser printing on the protective film.

Japanese Patent No. 5432553

  The present invention provides a protective film-forming composite sheet used to form a protective film on the back surface of a semiconductor chip, which can suppress blocking and can be clearly laser-printed on the protective film. This is the issue.

  The present invention comprises a support sheet, a protective film-forming film is provided on one surface of the support sheet, and a coating is provided on the surface of the support sheet opposite to the side provided with the protective film-forming film. The surface of the coating layer opposite to the side in contact with the support sheet has a surface roughness Ra smaller than the surface of the support sheet on the side having the coating layer. A composite sheet for forming a protective film is provided.

In the protective film-forming composite sheet of the present invention, the peeling film has a peeling force of 10 mN measured by the following method using the protective film-forming composite sheet provided with a peeling film on the protective film-forming film. / 50 mm or less may be sufficient.
(Measurement method of peel strength of release film)
The composite sheet for forming a protective film having a width of 50 mm and a length of 100 mm provided with a release film on the protective film-forming film, so that the coating layers are all directed in the same direction, and the total thickness of the coating layers Are laminated so that the outermost layer is a coating layer and the other outermost layer is a release film, and the laminate is laminated with the composite sheet for forming a protective film. The film was left to stand at 40 ° C. for 3 days while applying a force of 980.665 mN in the direction, and the release film closest to the outermost coating layer in the laminating direction was peeled off at 300 mm / min and at a peeling angle of 180 °. The peel force when peeled from the adjacent coating layer is measured.

In the protective film-forming composite sheet of the present invention, the support sheet is formed by laminating a base material and an adhesive layer, and the protective film-forming composite sheet includes the coating layer, the base material, the adhesive layer, and protection. The film forming film may be laminated in this order.
In the composite sheet for forming a protective film of the present invention, the pressure-sensitive adhesive layer may be energy ray curable or non-energy ray curable.
In the composite sheet for forming a protective film of the present invention, the protective film-forming film may be thermosetting or energy ray curable.

  The composite sheet for forming a protective film of the present invention is for forming a protective film on the back surface of a semiconductor chip. By using this composite sheet for forming a protective film, blocking of the composite sheet for forming a protective film is suppressed. And clear laser printing on the protective film.

It is sectional drawing which shows typically one Embodiment of the composite sheet for protective film formation which concerns on this invention. It is sectional drawing which shows typically other embodiment of the composite sheet for protective film formation which concerns on this invention. It is a top view which shows the composite sheet for protective film formation manufactured in the Example. It is sectional drawing which shows typically an example of the conventional composite sheet for protective film formation. It is sectional drawing which shows typically the other example of the conventional composite sheet for protective film formation.

◎ Composite sheet for forming a protective film The composite sheet for forming a protective film according to the present invention includes a support sheet, and includes a film for forming a protective film on one surface of the support sheet. A coating layer is provided on the surface opposite to the side provided with the film, and the surface of the coating layer opposite to the side in contact with the support sheet is provided with the coating layer of the support sheet. The surface roughness Ra is smaller than the surface on the side provided.

  In the protective film-forming composite sheet, the surface roughness Ra of the surface of the coating layer opposite to the side in contact with the support sheet is the surface of the support sheet on the side provided with the coating layer Is smaller than the surface roughness Ra. That is, the surface of the coating layer opposite to the side in contact with the support sheet is a smooth surface or a surface in which the degree of unevenness is suppressed. Therefore, when the laser beam is irradiated, irregular reflection of the laser beam on the surface where the surface roughness Ra of the coating layer is small is suppressed. Therefore, when the protective film after curing the protective film-forming film is irradiated with laser light through the support sheet from the coating layer side, laser printing can be clearly performed on the protective film.

  Moreover, the coating layer in the composite sheet for forming a protective film is appropriately slippery with respect to the contact with the coating layer and has antistatic properties. Therefore, when the protective film-forming composite sheet is wound into a roll, sticking of the laminated protective film-forming composite sheets, that is, blocking is suppressed.

  In the present specification, in the composite sheet for forming a protective film, the protective film-forming film is cured by heating or irradiation with energy rays to form a protective film, but the laminated structure of the support sheet and the protective film is also used. As long as it is maintained, it is referred to as a “composite sheet for forming a protective film”. Moreover, in the composite sheet for forming a protective film, when the support sheet is a laminated structure of a base material and an adhesive layer, a cured product of the base material and the adhesive layer, As long as the protective film-forming film or the laminated structure of the protective film is maintained, it is referred to as a “protective film-forming composite sheet”.

FIG. 1 is a cross-sectional view schematically showing one embodiment of a composite sheet for forming a protective film according to the present invention.
The composite sheet 1 for forming a protective film shown here includes a support sheet 10, a film 13 for forming a protective film on one surface 10 a of the support sheet 10, and on the other surface (back surface) 10 b of the support sheet 10. A coating layer 14 is provided. Further, the support sheet 10 is formed by laminating a base material 11 and a pressure-sensitive adhesive layer 12, and includes a pressure-sensitive adhesive layer 12 on one surface 11 a of the base material 11, on the other surface (back surface) 11 b of the base material 11. Is provided with a coating layer 14, and a protective film-forming film 13 is provided on the pressure-sensitive adhesive layer 12. The protective film-forming composite sheet 1 further includes a release film 15 on the protective film-forming film 13, and the release film 15 is removed when the protective film-forming composite sheet 1 is used. The protective film-forming film 13 becomes a protective film by curing.

In the protective film-forming composite sheet 1, the pressure-sensitive adhesive layer 12 is laminated on the surface 11 a of the substrate 11, and the protective film-forming film 13 is laminated on a part of the surface 12 a of the pressure-sensitive adhesive layer 12. Then, on the exposed surface of the surface 12 a of the pressure-sensitive adhesive layer 12 where the protective film-forming film 13 is not laminated and the surface 13 a (in other words, the upper surface and the side surface) of the protective film-forming film 13, the release film 15. Are stacked.
Note that a gap may exist between the release film 15 and the surface 12 a of the pressure-sensitive adhesive layer 12 or the surface 13 a of the protective film forming film 13. For example, in the side surface of the protective film-forming film 13 and the surface 12 a of the pressure-sensitive adhesive layer 12, the voids are likely to occur in the vicinity of the protective film-forming film 13.

  In the protective film forming composite sheet 1, the surface (back surface) 10 b opposite to the surface (front surface) 10 a provided with the protective film forming film 13 of the support sheet 10, in other words, the adhesive layer 12 of the substrate 11. The surface (back surface) 11b opposite to the surface (front surface) 11a provided with is an uneven surface. The coating layer 14 is provided so as to cover the uneven surface. The surface (back surface) 14b opposite to the surface (front surface) 14a in contact with the support sheet 10 (base material 11) of the coating layer 14 is the back surface 10b of the support sheet 10 (in other words, the back surface of the base material 11). The surface roughness Ra is smaller than 11b). When laser printing is performed on a protective film (not shown) formed from the protective film forming film 13, the surface of the protective film on the support sheet 10 side is irradiated with laser light from the coating layer 14 side. At this time, as described above, since the surface roughness Ra of the back surface 14b of the coating layer 14 is small, the irregular reflection of the laser light on the coating layer 14 is suppressed. Therefore, clear laser printing can be performed on the protective film.

  In the present specification, “surface roughness Ra” means a so-called arithmetic average roughness defined in JIS B0601: 2001 unless otherwise specified.

  Further, since the protective film-forming composite sheet 1 includes the coating layer 14, even when the protective film-forming composite sheet 1 is wound up to form a roll, the laminated protective film-forming composite sheets 1 are attached to each other, that is, blocking. Is suppressed. More specifically, sticking between the back surface 11b of the substrate 11 and the exposed surface (front surface) 15a of the release film 15 is suppressed.

  In the composite sheet 1 for forming a protective film, the surface 11a of the base material 11 is a smooth surface here, but may be an uneven surface with low smoothness. However, as will be described later, it is easier to suppress the generation of voids between the base material 11 and the pressure-sensitive adhesive layer 12 and to make the protective film-forming composite sheet 1 have preferable characteristics. The surface 11a of the substrate 11 is preferably a smooth surface.

  In the protective film-forming composite sheet 1 shown in FIG. 1, the release film 15 is removed during use, and the back surface of a semiconductor wafer (not shown) is attached to the front surface 13 a of the protective film-forming film 13. Further, the exposed surface of the surface 12a of the pressure-sensitive adhesive layer 12 on which the protective film forming film 13 is not laminated is attached to a jig such as a ring frame.

  FIG. 2 is a cross-sectional view schematically showing another embodiment of the composite sheet for forming a protective film according to the present invention. 2, the same components as those shown in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and detailed description thereof is omitted. This also applies to the drawings after FIG.

  In the protective film-forming composite sheet 2 shown here, a protective film-forming film 23 is laminated on the entire surface 12 a of the pressure-sensitive adhesive layer 12, and jig bonding is performed on a part of the surface 23 a of the protective film-forming film 23. The agent layer 16 is laminated. Furthermore, in the protective film-forming composite sheet 2, the exposed surface of the surface 23 a of the protective film-forming film 23 where the jig adhesive layer 16 is not laminated and the surface 16 a of the jig adhesive layer 16. The release film 15 is laminated on (in other words, the upper surface and the side surface). Except for these points, the protective film-forming composite sheet 2 is the same as the protective film-forming composite sheet 1 shown in FIG.

  A gap may exist between the release film 15 and the surface 23a of the protective film-forming film 23 or the surface 16a of the jig adhesive layer 16. For example, in the side surface of the jig adhesive layer 16 and the surface 23 a of the protective film forming film 23, the gap portion is likely to occur in the vicinity of the jig adhesive layer 16.

  Also in the protective film-forming composite sheet 2, as in the case of the protective film-forming composite sheet 1, the back surface 10 b of the support sheet 10 (the back surface 11 b of the base material 11) is an uneven surface. A layer 14 is provided so as to cover the uneven surface. Therefore, the surface roughness Ra of the back surface 14 b of the coating layer 14 is smaller than that of the back surface 10 b of the support sheet 10. Therefore, clear laser printing can be performed on the protective film formed from the protective film-forming film 23.

  Moreover, even if it is a case where the composite sheet 2 for protective film formation is provided with the coating layer 14 and it rolls up and it is a roll, the composite sheet 2 for protective film formation laminated | stacked, ie, blocking Is suppressed.

  In the protective film forming composite sheet 2 shown in FIG. 2, the release film 15 is removed during use, and the back surface of the semiconductor wafer (not shown) is attached to the front surface 23 a of the protective film forming film 23. Further, the upper surface of the surface 16a of the jig adhesive layer 16 is attached to a jig such as a ring frame.

The composite sheet for forming a protective film according to the present invention is not limited to that shown in FIGS. 1 and 2, and a part of the configuration shown in FIGS. In addition, other configurations may be added to those described above.
Hereinafter, each structure of the composite film for protective film formation concerning this invention is demonstrated in detail.

○ Support sheet The support sheet is not particularly limited as long as the protective film-forming film can be provided. As the support sheet, for example, a release sheet used to prevent adhesion of dust or the like to the surface of the protective film forming film, and a dicing sheet used to protect the surface of the protective film forming film in a dicing process or the like That play the role of.
Preferable examples of the support sheet include those composed only of a base material usually used in the field of semiconductor wafer processing sheets, and those obtained by laminating a base material and an adhesive layer.

  The support sheet may be composed of one layer (single layer) or may be composed of two or more layers. When the support sheet is composed of a plurality of layers, the plurality of layers may be the same as or different from each other. That is, all the layers may be the same, all the layers may be different, or only some of the layers may be the same. And when several layers differ from each other, the combination of these several layers is not specifically limited. Here, the plurality of layers being different from each other means that at least one of the material and the thickness of each layer is different from each other.

The thickness of the support sheet may be appropriately selected according to the purpose, but laser printing can be performed more clearly on the protective film, and the composite sheet for forming the protective film has sufficient flexibility. It is preferably 10 to 500 μm, more preferably 20 to 350 μm, and particularly preferably 30 to 200 μm, for example, any of 40 to 175 μm and 50 to 150 μm, from the viewpoint that the adhesiveness to the semiconductor wafer can be improved. There may be.
Here, “the thickness of the support sheet” means the total thickness of each layer constituting the support sheet. For example, in the case of a support sheet in which a base material and an adhesive layer are laminated, the base material And the total thickness of the pressure-sensitive adhesive layer.
Note that at least one surface of the support sheet can be an uneven surface, but the thickness of the support sheet is calculated by using the tip of the protrusion as one starting point at a portion including the protrusion on the uneven surface of the support sheet. be able to.

-Base material It is preferable that the material of the said base material is various resin.
Specific examples of the resin include polyethylene (low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE, etc.)), polypropylene, ethylene / propylene copolymer, polybutene, polybutadiene, Polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyurethane, polyurethane acrylate, polyimide, ethylene / vinyl acetate copolymer, ionomer resin, ethylene / (meth) acrylic acid Copolymers, ethylene / (meth) acrylic acid ester copolymers, polystyrene, polycarbonate, fluororesin, and water additives, modified products, cross-linked products or copolymers of any of these resins. .
In this specification, “(meth) acrylic acid” is a concept including both “acrylic acid” and “methacrylic acid”.

  When the support sheet is formed by laminating a base material and another material such as an adhesive layer, the thickness of the base material can be appropriately selected according to the purpose, but is 15 to 300 μm. Is preferable, and it is more preferable that it is 20-200 micrometers, for example, any of 30-175 micrometers, 40-150 micrometers, and 50-125 micrometers may be sufficient. When the thickness of the substrate is within such a range, the flexibility of the composite sheet for forming a protective film and the adhesiveness to a semiconductor wafer or semiconductor chip are further improved.

The substrate may be composed of one layer (single layer) or may be composed of two or more layers. When a base material consists of multiple layers, these multiple layers may be the same as or different from each other. Here, “the plurality of layers may be the same as or different from each other” means the same as in the case of the above-described support sheet.
In the case where the substrate is composed of a plurality of layers, the total thickness of each layer may be set to the preferable thickness of the substrate.

The surface roughness Ra of the surface (surface) provided with the adhesive layer of the base material is preferably 0.001 to 0.1 μm, more preferably 0.005 to 0.08 μm, and It is especially preferable that it is 01-0.04 micrometer. When the surface roughness Ra of the substrate surface is not more than the upper limit value, laser printing can be performed more clearly on the protective film.
The surface roughness Ra of the substrate surface can be adjusted by, for example, molding conditions of the substrate, surface treatment conditions of the substrate, and the like.

In addition, as a method of dividing the semiconductor wafer into semiconductor chips by dicing, for example, blade dicing for cutting the semiconductor wafer using a blade, laser dicing for cutting the semiconductor wafer by laser irradiation, or spraying water containing an abrasive And a method using water dicing or the like for cutting a semiconductor wafer.
On the other hand, as a method of dividing a semiconductor wafer into semiconductor chips, in addition to the method using these dicing methods, the laser beam in the infrared region is irradiated so as to be focused on the focal point set inside the semiconductor wafer. Then, after forming a modified layer inside the semiconductor wafer, a method of dividing the semiconductor wafer into individual pieces by applying force to the semiconductor wafer to form the modified layer is also mentioned. .
When the surface roughness Ra of the substrate surface is, for example, 0.01 to 0.2 μm, the protective film-forming composite sheet provided with such a substrate has a modified layer in the semiconductor wafer described above. It is suitable for use in forming a semiconductor wafer into individual pieces.

On the other hand, the surface roughness Ra of the surface (back surface) opposite to the surface (front surface) provided with the adhesive layer of the substrate, in other words, the surface (surface) provided with the protective film forming film of the support sheet. The surface roughness Ra of the opposite surface (back surface) is preferably 0.001 to 4 μm, more preferably 0.005 to 3.7 μm, and 0.01 to 3.4 μm. It is more preferable that the thickness is 0.02 to 3.1 μm. When the surface roughness Ra on the back surface of the substrate is less than or equal to the upper limit, the surface roughness Ra on the surface of the coating layer opposite to the side in contact with the support sheet can be more easily reduced, and the protective film In contrast, it becomes easier to perform laser printing clearly.
The surface roughness Ra on the back surface of the base material can be adjusted by, for example, molding conditions of the base material, surface treatment conditions of the base material, and the like.

The resin that is the material of the base material may be cross-linked.
In addition, the base material containing the resin as a constituent material may be a sheet formed by extrusion molding of a thermoplastic resin, or may be stretched, and is thin by a known means of a curable resin. It may be formed into a sheet by layering and curing.
Further, the base material may be colored or printed.

The base material is preferably one containing polypropylene from the viewpoint that it has excellent heat resistance and has an appropriate flexibility so that it has expandability and pick-up suitability.
The base material containing polypropylene may be, for example, a single layer or a plurality of layers made of only polypropylene, or a plurality of layers (two or more layers) in which a polypropylene layer and a resin layer other than polypropylene are laminated. It may be a base material.
When the protective film-forming film is thermosetting, the base material has heat resistance, so that deterioration of the base material due to heat can be suppressed, and occurrence of defects in the manufacturing process of the semiconductor device can be effectively suppressed. .

  In order to improve the adhesiveness with the adhesive layer or the protective film forming film provided on the base material, the surface is roughened by sandblasting, solvent treatment, etc .; corona discharge treatment, electron beam irradiation treatment, plasma treatment The surface may be subjected to oxidation treatment such as ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, and hot air treatment. Further, the base material may be one whose surface is primed.

-Adhesive layer The said adhesive layer can use a well-known thing suitably.
An adhesive layer can be formed using the adhesive composition containing various components, such as an adhesive, for comprising this. The ratio of the content of 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, “normal temperature” means a temperature that is not particularly cooled or heated, that is, a normal temperature, and includes a temperature of 15 to 25 ° C., for example.

  Although the thickness of an adhesive layer can be suitably selected according to the objective, it is preferable that it is 1-100 micrometers, It is more preferable that it is 2-80 micrometers, It is especially preferable that it is 3-50 micrometers, For example, 3-3 Any of 35 micrometers, 3-20 micrometers, and 3-10 micrometers may be sufficient.

The pressure-sensitive adhesive layer may be composed of one layer (single layer) or may be composed of two or more layers. When an adhesive layer consists of multiple layers, these multiple layers may be the same or different from each other. Here, “the plurality of layers may be the same as or different from each other” means the same as in the case of the above-described support sheet.
In the case where the pressure-sensitive adhesive layer is composed of a plurality of layers, the total thickness of each layer may be set to the thickness of the preferable pressure-sensitive adhesive layer.

  Examples of the adhesive include adhesive resins such as acrylic resins, urethane resins, rubber resins, silicone resins, and vinyl ether resins. Moreover, as said adhesive, when classify | categorized from the viewpoint of the function, energy-beam curable resin etc. are mentioned, for example.

In the present specification, “energy beam” means an electromagnetic wave or a charged particle beam having energy quanta, and examples thereof include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated by using, for example, a high-pressure mercury lamp, a fusion H lamp, a xenon lamp, a black light, an LED lamp, or the like as an ultraviolet ray source. The electron beam can be emitted by an electron beam accelerator or the like.
In addition, in this specification, “energy ray curable” means a property that is cured by irradiating energy rays, and “non-energy ray curable” is a property that is not cured even when irradiated with energy rays. Means.

Examples of the energy ray curable resin include those having a polymerizable group such as a (meth) acryloyl group and a vinyl group.
The adhesive resin is preferably an acrylic resin, and more preferably a (meth) acrylic acid ester copolymer including a structural unit derived from a (meth) acrylic acid ester.

  When the pressure-sensitive adhesive layer contains a component that is polymerized by irradiation with energy rays, such as an energy ray-curable resin, the pressure-sensitive adhesive layer becomes energy-ray curable and decreases its adhesiveness by irradiation with energy rays. By doing so, it becomes easy to pick up a semiconductor chip with a protective film, which will be described later. Such a pressure-sensitive adhesive layer can be formed using, for example, various pressure-sensitive adhesive compositions containing a component that is polymerized by irradiation with energy rays.

<< Adhesive composition >>
Preferred examples of the pressure-sensitive adhesive composition include those containing a component that polymerizes upon irradiation with energy rays. Examples of such a pressure-sensitive adhesive composition include those containing an acrylic resin and an energy beam polymerizable compound (hereinafter sometimes abbreviated as “pressure-sensitive adhesive composition (i)”), and having a hydroxyl group. And those containing the acrylic resin having a polymerizable group in the side chain and an isocyanate crosslinking agent (hereinafter sometimes abbreviated as “adhesive composition (ii)”). It is done. Examples of the acrylic resin having a hydroxyl group and having a polymerizable group in the side chain described above include an acrylic resin having a hydroxyl group and having a polymerizable group in the side chain via a urethane bond. It is done.

<Adhesive composition (i)>
The pressure-sensitive adhesive composition (i) contains the acrylic resin and an energy beam polymerizable compound as essential components.
Hereinafter, each component will be described.

[Acrylic resin]
Preferred examples of the acrylic resin in the pressure-sensitive adhesive composition (i) include polymerization of (meth) acrylic acid ester as a monomer and a monomer other than (meth) acrylic acid ester used as necessary. (Meth) acrylic acid ester copolymer obtained by doing this.

Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, (meth) Hexyl acrylate, heptyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, (meth) acrylic acid Isononyl, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), tridecyl (meth) acrylate, tetradecyl (meth) acrylate ((meth) acrylic acid) Myristyl), pentadecyl (meth) acrylate, hexa (meth) acrylate Sil (palmethyl (meth) acrylate), heptadecyl (meth) acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate), isooctadecyl (meth) acrylate (isostearyl (meth) acrylate), etc. And (meth) acrylic acid alkyl ester in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms;
(Meth) acrylic acid cycloalkyl esters such as (meth) acrylic acid isobornyl, (meth) acrylic acid dicyclopentanyl;
(Meth) acrylic acid aralkyl esters such as (meth) acrylic acid benzyl;
(Meth) acrylic acid cycloalkenyl esters such as (meth) acrylic acid dicyclopentenyl ester;
(Meth) acrylic acid cycloalkenyloxyalkyl esters such as (meth) acrylic acid dicyclopentenyloxyethyl ester;
(Meth) acrylic imide;
Glycidyl group-containing (meth) acrylic acid ester such as (meth) acrylic acid glycidyl;
Hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meta ) Hydroxyl group-containing (meth) acrylic acid esters such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylate.

  Examples of the monomer other than the (meth) acrylic acid ester include (meth) acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide and the like.

  As for various monomers, such as said (meth) acrylic acid ester and monomers other than said (meth) acrylic acid ester which comprise acrylic resin, all may be only 1 type and 2 or more types may be sufficient as them.

  The acrylic resin contained in the pressure-sensitive adhesive composition (i) may be only one type or two or more types.

  It is preferable that content of acrylic resin of adhesive composition (i) is 40-99 mass% with respect to the total amount of all the containing components other than the solvent in adhesive composition (i), 50- More preferably, it is 91% by weight.

[Energy ray polymerizable compound]
The energy ray polymerizable compound is a compound that is polymerized and cured by irradiation with energy rays, and examples thereof include those having an energy ray polymerizable group such as an energy ray curable double bond in the molecule. .

Examples of the energy beam polymerizable compound include low molecular weight compounds (monofunctional or polyfunctional monomers and oligomers) having an energy beam polymerizable group.
More specifically, as the energy ray polymerizable compound, for example, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1, 4 -Acrylates such as butylene glycol diacrylate, 1,6-hexanediol diacrylate;
Cyclic aliphatic skeleton-containing acrylates such as dicyclopentadiene dimethoxydiacrylate;
Examples include acrylate compounds such as polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy-modified acrylate, polyether acrylate, and itaconic acid oligomer.

  The molecular weight of the energy beam polymerizable compound is preferably 100 to 30000, and more preferably 300 to 10000.

  The energy ray polymerizable compound contained in the pressure-sensitive adhesive composition (i) may be only one type or two or more types.

  The content of the energy ray polymerizable compound of the pressure-sensitive adhesive composition (i) is preferably 1 to 125 parts by mass, and 10 to 125 parts by mass with respect to 100 parts by mass of the acrylic resin. It is more preferable.

[Photopolymerization initiator]
The pressure-sensitive adhesive composition (i) may contain a photopolymerization initiator in addition to the acrylic resin and the energy beam polymerizable compound.
The photopolymerization initiator may be a known one.
Specific examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, α-hydroxy-α, α′-dimethylacetophenone, 2-methyl- 2-hydroxypropiophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1 -Α-ketol compounds such as ON;
Acetophenone compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one ;
Benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether and anisoin methyl ether;
Ketal compounds such as benzyldimethyl ketal;
Aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride;
Photoactive oxime compounds such as 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime;
Benzophenone compounds such as benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone;
Thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4 -Thioxanthone compounds such as diisopropylthioxanthone;
Examples include camphorquinone; halogenated ketone; acyl phosphinoxide; acyl phosphonate.

  The photopolymerization initiator contained in the pressure-sensitive adhesive composition (i) may be one kind or two or more kinds.

  When using a photoinitiator, content of the photoinitiator of adhesive composition (i) is 0.1-10 mass parts with respect to 100 mass parts of said energy-beam polymeric compounds content. It is preferably 1 to 5 parts by mass. The effect by using a photoinitiator is fully acquired because the said content of a photoinitiator is more than the said lower limit. Moreover, generation | occurrence | production of the by-product from an excess photoinitiator is suppressed because the said content of a photoinitiator is below the said upper limit, and hardening of an adhesive layer advances more favorably.

[Crosslinking agent]
The pressure-sensitive adhesive composition (i) may contain a crosslinking agent in addition to the acrylic resin and the energy beam polymerizable compound.
Examples of the crosslinking agent include organic polyvalent isocyanate compounds and organic polyvalent imine compounds.

  Examples of the organic polyvalent isocyanate compound include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, and trimers, isocyanurates, and adducts of these compounds; Examples thereof include a terminal isocyanate urethane prepolymer obtained by reacting a polyvalent isocyanate compound, an aliphatic polyvalent isocyanate compound or an alicyclic polyvalent isocyanate compound with a polyol compound. The adduct is composed of the aromatic polyvalent isocyanate compound, the aliphatic polyvalent isocyanate compound or the alicyclic polyvalent isocyanate compound, and low molecular activity such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil. It means a reaction product with a hydrogen-containing compound.

  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 Diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; trimethylol A compound in which either or both of tolylene diisocyanate and hexamethylene diisocyanate are added to the hydroxyl groups of all or part of a polyol such as propane. Lysine diisocyanate, and the like.

  Examples of the organic polyvalent imine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, and tetramethylolmethane. -Tri-β-aziridinylpropionate, N, N′-toluene-2,4-bis (1-aziridinecarboxamide) triethylenemelamine and the like.

  When an isocyanate compound is used as the crosslinking agent, it is preferable to use a hydroxyl group-containing polymer as the acrylic resin. When the crosslinking agent has an isocyanate group and the acrylic resin has a hydroxyl group, a crosslinked structure can be easily introduced into the pressure-sensitive adhesive layer by a reaction between the isocyanate group and the hydroxyl group.

  As for the crosslinking agent which adhesive composition (i) contains, only 1 type may be sufficient and 2 or more types may be sufficient.

  When the crosslinking agent is used, the content of the crosslinking agent in the pressure-sensitive adhesive composition (i) is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the acrylic resin. It is more preferably 1 to 16 parts by mass.

[solvent]
The pressure-sensitive adhesive composition (i) preferably further contains a solvent in addition to the acrylic resin and the energy beam polymerizable compound.
The solvent is not particularly limited.
Preferred examples of the solvent 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; Examples thereof include ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone.
As for the solvent which adhesive composition (i) contains, only 1 type may be sufficient and 2 or more types may be sufficient.

  When the pressure-sensitive adhesive composition (i) contains a solvent, the content of the solvent in the pressure-sensitive adhesive composition (i) is preferably 40 to 90% by mass, and more preferably 50 to 80% by mass. .

[Other ingredients]
The pressure-sensitive adhesive composition (i) contains, in addition to the acrylic resin and the energy beam polymerizable compound, other components not corresponding to the photopolymerization initiator, the crosslinking agent, and the solvent within a range not impairing the effects of the present invention. You may contain.
The other components may be known ones, can be arbitrarily selected according to the purpose, and are not particularly limited. Examples of preferable other components include various additives such as dyes, pigments, deterioration inhibitors, antistatic agents, flame retardants, silicone compounds, and chain transfer agents.
The said other component which an adhesive composition (i) contains may be only 1 type, and 2 or more types may be sufficient as it.

<Adhesive composition (ii)>
The pressure-sensitive adhesive composition (ii) contains an acrylic resin having a hydroxyl group and a polymerizable group in the side chain, and an isocyanate crosslinking agent as essential components. Here, as said acrylic resin, the acrylic resin etc. which have a hydroxyl group and have a polymeric group in a side chain through a urethane bond are mentioned, for example.
When the pressure-sensitive adhesive composition (ii) is used, the acrylic resin has a polymerizable group in the side chain, so that the energy ray polymerizable compound is used as in the case of the pressure-sensitive adhesive composition (i). Compared with the case where the polymerization reaction is performed by irradiation with energy rays, the peelability from the adherend is improved due to the reduced adhesiveness of the pressure-sensitive adhesive layer after the polymerization reaction (curing), and the pick-up property of the semiconductor chip with a protective film is improved. To do.
In the present specification, the description of “acrylic resin” in the pressure-sensitive adhesive composition (ii) means “acrylic resin having a polymerizable group in a side chain” unless otherwise specified. To do.

[Acrylic resin]
Examples of the acrylic resin having a polymerizable group in the side chain include, for example, a (meth) acrylic acid ester having no hydroxyl group as a monomer (referred to as “hydroxyl-free (meth) acrylic acid ester” in this specification). And a hydroxyl group-containing compound such as a (meth) acrylic acid ester having a hydroxyl group (in the present specification, sometimes referred to as “hydroxyl group-containing (meth) acrylic acid ester”). Examples thereof include those obtained by reacting the hydroxyl group of the obtained hydroxyl group-containing copolymer with an isocyanate group of a compound having an isocyanate group and a polymerizable group to form a urethane bond.

Examples of the hydroxyl group-free (meth) acrylic acid ester include those other than the hydroxyl group-containing (meth) acrylic acid ester among the (meth) acrylic acid esters in the pressure-sensitive adhesive composition (i).
Moreover, as said hydroxyl-containing compound, the same thing as the hydroxyl-containing (meth) acrylic acid ester in adhesive composition (i) is mentioned.
Each of the hydroxyl group-free (meth) acrylic acid ester and the hydroxyl group-containing compound constituting the acrylic resin may be one type or two or more types.

Examples of the compound having an isocyanate group and a polymerizable group include isocyanate group-containing (meth) acrylic acid esters such as 2-methacryloyloxyethyl isocyanate.
The compound which has the said isocyanate group and polymeric group which comprises the said acrylic resin may be only 1 type, and 2 or more types may be sufficient as it.

  The acrylic resin contained in the pressure-sensitive adhesive composition (ii) may be one type or two or more types.

  The content of the acrylic resin in the pressure-sensitive adhesive composition (ii) is preferably 80 to 99% by mass with respect to the total amount of all the components other than the solvent in the pressure-sensitive adhesive composition (ii), 90 to More preferably, it is 97 mass%.

[Isocyanate-based crosslinking agent]
As said isocyanate type crosslinking agent, the same thing as the said organic polyvalent isocyanate compound which is a crosslinking agent in adhesive composition (i) is mentioned, for example.

  As for the isocyanate type crosslinking agent which adhesive composition (ii) contains, only 1 type may be sufficient and 2 or more types may be sufficient.

  The number of moles of isocyanate groups possessed by the isocyanate-based crosslinking agent in the pressure-sensitive adhesive composition (ii) is 0.2 to 3 times the number of moles of hydroxyl groups possessed by the acrylic resin in the pressure-sensitive adhesive composition (ii). Preferably there is. When the number of moles of the isocyanate group is equal to or more than the lower limit, the peelability from the adherend due to the decrease in the tackiness of the pressure-sensitive adhesive layer after curing is improved, and the pick-up property of the semiconductor chip with a protective film is improved. Moreover, generation | occurrence | production of the by-product by reaction of isocyanate type crosslinking agents can be suppressed more because the said mole number of an isocyanate group is below the said upper limit.

The content of the isocyanate-based crosslinking agent in the pressure-sensitive adhesive composition (ii) is preferably adjusted as appropriate so that the number of moles of the isocyanate group falls within the above range.
Furthermore, the content of the isocyanate-based crosslinking agent in the pressure-sensitive adhesive composition (ii) satisfies the condition for the number of moles of the isocyanate group, and is 0.1% relative to 100 parts by mass of the acrylic resin content. It is preferably 01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and particularly preferably 0.3 to 12 parts by mass.

[Photopolymerization initiator]
The pressure-sensitive adhesive composition (ii) may contain a photopolymerization initiator in addition to the acrylic resin and the isocyanate-based crosslinking agent.
As said photoinitiator, the same thing as the case of adhesive composition (i) is mentioned, for example.
The photopolymerization initiator contained in the pressure-sensitive adhesive composition (ii) may be only one type or two or more types.

  When using a photoinitiator, it is preferable that content of the photoinitiator of adhesive composition (ii) is 0.05-20 mass parts with respect to 100 mass parts of acrylic resin content. . The effect by using a photoinitiator is fully acquired because the said content of a photoinitiator is more than the said lower limit. Moreover, generation | occurrence | production of the by-product from an excess photoinitiator is suppressed because the said content of a photoinitiator is below the said upper limit, and hardening of an adhesive layer advances more favorably.

[solvent]
The pressure-sensitive adhesive composition (ii) preferably further contains a solvent in addition to the acrylic resin and the isocyanate-based crosslinking agent.
As said solvent, the same thing as the case of adhesive composition (i) is mentioned, for example.
As for the solvent which adhesive composition (ii) contains, 1 type may be sufficient and 2 or more types may be sufficient as it.

  When adhesive composition (ii) contains a solvent, it is preferable that content of the solvent of adhesive composition (ii) is 40-90 mass%, and it is more preferable that it is 50-80 mass%. .

[Other ingredients]
The pressure-sensitive adhesive composition (ii) contains, in addition to the acrylic resin and the isocyanate-based crosslinking agent, other components that do not correspond to the photopolymerization initiator and the solvent, as long as the effects of the present invention are not impaired. Also good.
As said other component, the same thing as the case of adhesive composition (i) is mentioned, for example.
The said other component which an adhesive composition (ii) contains may be only 1 type, and 2 or more types may be sufficient as it.

So far, the pressure-sensitive adhesive composition containing a component that is polymerized by irradiation with energy rays has been described. Also good. That is, the pressure-sensitive adhesive layer may be non-energy ray curable without energy ray curable.
Preferred examples of such a non-energy ray-curable pressure-sensitive adhesive composition include an acrylic resin and a crosslinking agent (hereinafter, sometimes abbreviated as “pressure-sensitive adhesive composition (iii)”). Etc. The pressure-sensitive adhesive composition (iii) may contain an optional component such as a solvent and other components not corresponding to the solvent.

<Adhesive composition (iii)>
The acrylic resin, crosslinking agent, solvent and other components contained in the adhesive composition (iii) are the same as the acrylic resin, crosslinking agent, solvent and other components in the adhesive composition (i), respectively. It is.

  The content of the acrylic resin in the pressure-sensitive adhesive composition (iii) is preferably 40 to 99% by mass with respect to the total amount of all components other than the solvent in the pressure-sensitive adhesive composition (iii), and is preferably 50 to It is more preferable that it is 93 mass%.

  The content of the crosslinking agent in the pressure-sensitive adhesive composition (iii) is preferably 3 to 30 parts by mass and more preferably 5 to 25 parts by mass with respect to 100 parts by mass of the acrylic resin. .

  The pressure-sensitive adhesive composition (iii) is the same as the pressure-sensitive adhesive composition (i) except for the points described above.

<< Method for producing pressure-sensitive adhesive composition >>
The pressure-sensitive adhesive compositions such as pressure-sensitive adhesive compositions (i) to (iii) are components for constituting each pressure-sensitive adhesive composition such as the pressure-sensitive adhesive and components other than the pressure-sensitive adhesive as necessary. It is obtained by blending.
The order of addition at the time of blending each component is not particularly limited, and two or more components may be added simultaneously.
The method of mixing each component at the time of compounding is not particularly limited, from a known method such as a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by applying ultrasonic waves What is necessary is just to select suitably.
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 adjusted as appropriate, but the temperature is preferably 15 to 30 ° C.

○ Protective film-forming film The protective film-forming film may be either thermosetting or energy ray-curable. The film for forming a protective film is cured and finally becomes a protective film having high impact resistance. This protective film prevents the occurrence of cracks in the semiconductor chip after the dicing process, for example.
The protective film-forming film may be referred to as a thermosetting protective film-forming composition or an energy ray-curable protective film-forming composition (hereinafter referred to as a “protective film-forming composition”). ).

  The protective film-forming film may be only one layer (single layer), or may be two or more layers. In the case of a plurality of layers, these layers may be the same or different from each other. The combination is not particularly limited.

  Although the thickness of the film for protective film formation is not specifically limited, It is preferable that it is 1-100 micrometers, It is more preferable that it is 5-75 micrometers, It is especially preferable that it is 5-50 micrometers. When the thickness of the protective film-forming film is equal to or more than the lower limit value, the adhesive force to the adherend semiconductor wafer and semiconductor chip is further increased. Moreover, when the thickness of the protective film-forming film is not more than the above upper limit value, the protective film, which is a cured product, can be more easily cut using the shearing force when the semiconductor chip is picked up.

-Film for forming a thermosetting protective film Examples of preferable film for forming a thermosetting protective film include those containing a polymer component (A) and a thermosetting component (B). The polymer component (A) is a component that can be regarded as formed by polymerization reaction of the polymerizable compound. The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction using heat as a reaction trigger. In the present invention, the polymerization reaction includes a polycondensation reaction.

<< The composition for thermosetting protective film formation >>
The film for forming a thermosetting protective film can be formed using a composition for forming a thermosetting protective film containing the constituent materials. For example, the composition for forming a thermosetting protective film is applied to the surface to be formed of the film for forming a thermosetting protective film, and dried as necessary to form a thermosetting protective film on the target site. A film can be formed. The ratio of the content of components that do not vaporize at room temperature in the thermosetting protective film-forming composition is usually the same as the content ratio of the components of the thermosetting protective film-forming film. Here, “normal temperature” is as described above.

  Application of the thermosetting protective film forming 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, Examples include a method using various coaters such as a knife coater, a screen coater, a Meyer bar coater, and a kiss coater.

  Although the drying conditions of the composition for thermosetting protective film formation are not specifically limited, When the composition for thermosetting protective film formation contains the solvent mentioned later, it is preferable to heat-dry. The composition for forming a thermosetting protective film containing a solvent is preferably dried at 70 to 130 ° C. for 10 seconds to 5 minutes, for example.

<Composition for forming protective film (III-1)>
As the 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) May be abbreviated as “protective film-forming composition (III-1)”).

[Polymer component (A)]
The polymer component (A) is a polymer compound for imparting film-forming properties, flexibility and the like to the thermosetting protective film-forming film.
The polymer component (A) contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one type, two or more types, or two or more types. These combinations and ratios can be arbitrarily selected.

  Examples of the polymer component (A) include an acrylic resin (a resin having a (meth) acryloyl group), a polyester, a urethane resin (a resin having a urethane bond), an acrylic urethane resin, and a silicone resin (having a siloxane bond). Resin), rubber resin (resin having a rubber structure), phenoxy resin, thermosetting polyimide and the like, and acrylic resin is preferable.

As said acrylic resin in a polymer component (A), a well-known acrylic polymer is mentioned.
The weight average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1500,000. When the weight average molecular weight of the acrylic resin is equal to or more than the lower limit, the shape stability (time stability during storage) of the thermosetting protective film-forming film is improved. In addition, when the weight average molecular weight of the acrylic resin is not more than the above upper limit value, the thermosetting protective film forming film easily follows the uneven surface of the adherend, and the adherend and the thermosetting protective film are formed. Occurrence of voids and the like with the film is further suppressed.

  The glass transition temperature (Tg) of the acrylic resin is preferably −60 to 70 ° C., and more preferably −30 to 50 ° C. When the Tg of the acrylic resin is equal to or higher than the lower limit, the adhesive force between the protective film and the support sheet is suppressed, and the peelability of the support sheet is improved. Moreover, the adhesive force with the to-be-adhered body of the thermosetting protective film formation film and a protective film improves because Tg of acrylic resin is below the said upper limit.

  The acrylic resin is selected from, for example, a polymer of one or more (meth) acrylic acid esters; (meth) acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like. Examples include copolymers of two or more monomers.

Examples of the (meth) acrylic acid ester constituting the acrylic resin include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (meth ) N-butyl acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic Heptyl acid, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate , Undecyl (meth) acrylate, dodecyl (meth) acrylate ((meth) acrylic acid (Uril), tridecyl (meth) acrylate, tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (palmityl (meth) acrylate), (meth) (Meth) acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester, such as heptadecyl acrylate and octadecyl (meth) acrylate (stearyl (meth) acrylate), has a chain structure having 1 to 18 carbon atoms;
(Meth) acrylic acid cycloalkyl esters such as (meth) acrylic acid isobornyl, (meth) acrylic acid dicyclopentanyl;
(Meth) acrylic acid aralkyl esters such as (meth) acrylic acid benzyl;
(Meth) acrylic acid cycloalkenyl esters such as (meth) acrylic acid dicyclopentenyl ester;
(Meth) acrylic acid cycloalkenyloxyalkyl esters such as (meth) acrylic acid dicyclopentenyloxyethyl ester;
(Meth) acrylic imide;
Glycidyl group-containing (meth) acrylic acid ester such as (meth) acrylic acid glycidyl;
Hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meta ) Hydroxyl-containing (meth) acrylic acid esters such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylate;
Examples thereof include substituted amino group-containing (meth) acrylic esters such as (meth) acrylic acid N-methylaminoethyl. Here, the “substituted amino group” means a group formed by replacing one or two hydrogen atoms of an amino group with a group other than a hydrogen atom.

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

  The monomer constituting the acrylic resin may be only one type, or two or more types, and in the case of two or more types, the combination and ratio thereof can be arbitrarily selected.

  The acrylic resin may have a functional group that can be bonded to other compounds such as a vinyl group, a (meth) acryloyl group, an amino group, a hydroxyl group, a carboxy group, and an isocyanate group. The functional group of the acrylic resin may be bonded to another compound via a cross-linking agent (F) described later, or may be directly bonded to another compound not via the cross-linking agent (F). . When the acrylic resin is bonded to another compound through the functional group, the reliability of the package obtained using the composite sheet for forming a protective film tends to be improved.

  In the present invention, as the polymer component (A), a thermoplastic resin other than the acrylic resin (hereinafter sometimes simply referred to as “thermoplastic resin”) may be used in combination with the acrylic resin. By using the thermoplastic resin, the peelability of the protective film from the support sheet is improved, and the thermosetting protective film-forming film easily follows the uneven surface of the adherend. The generation of voids and the like may be further suppressed between the protective protective film-forming film.

  The thermoplastic resin preferably has a weight average molecular weight of 1000 to 100,000, more preferably 3000 to 80,000.

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

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

  The thermoplastic resin contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one kind, two or more kinds, and when two or more kinds, These combinations and ratios can be arbitrarily selected.

  In the protective film forming composition (III-1), the ratio of the content of the polymer component (A) to the total content of all components other than the solvent (that is, the polymer component of the thermosetting protective film forming film) The content of (A) is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and 15 to 35% by mass, regardless of the type of the polymer component (A). It is particularly preferred.

  The polymer component (A) may also correspond to the thermosetting component (B). In this invention, when the composition (III-1) for protective film formation contains the component applicable to both such a polymer component (A) and a thermosetting component (B), it is for protective film formation. The composition (III-1) is considered to contain a polymer component (A) and a thermosetting component (B).

[Thermosetting component (B)]
The thermosetting component (B) is a component for curing a thermosetting protective film-forming film to form a hard protective film.
The thermosetting component (B) contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one type, two or more types, and two or more types. In such a case, the combination and ratio thereof can be arbitrarily selected.

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

(Epoxy thermosetting resin)
The epoxy thermosetting resin includes an epoxy resin (B1) and a thermosetting agent (B2).
The epoxy thermosetting resin contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one type, two or more types, or two or more types. These combinations and ratios can be arbitrarily selected.

・ Epoxy resin (B1)
Examples of the epoxy resin (B1) include known ones such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and hydrogenated products thereof, orthocresol novolac epoxy resins, dicyclopentadiene type epoxy resins, Biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenylene skeleton type epoxy resins, and the like, and bifunctional or higher functional epoxy compounds are listed.

  As the epoxy resin (B1), an epoxy resin having an unsaturated hydrocarbon group may be used. An epoxy resin having an unsaturated hydrocarbon group is more compatible with an acrylic resin than an epoxy resin having no unsaturated hydrocarbon group. Therefore, the reliability of the package obtained using the composite sheet for forming a protective film is improved by using an epoxy resin having an unsaturated hydrocarbon group.

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 can be obtained, for example, by addition reaction of (meth) acrylic acid or a derivative thereof to an epoxy group.
Moreover, as an epoxy resin which has an unsaturated hydrocarbon group, the compound etc. which the group which has an unsaturated hydrocarbon group directly couple | bonded with the aromatic ring etc. which comprise an epoxy resin are mentioned, 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, (meth). An acrylamide group etc. are mentioned, An acryloyl group is preferable.
In the present specification, the “derivative” means one obtained by substituting one or more hydrogen atoms of the original compound with a group (substituent) other than a hydrogen atom.

Although the number average molecular weight of an epoxy resin (B1) is not specifically limited, From the point of sclerosis | hardenability of the film for thermosetting protective film formation, and the intensity | strength and heat resistance of the protective film after hardening, it is 300-30000. Preferably, it is 300-10000, More preferably, it is 300-3000.
The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1100 g / eq, and more preferably 150 to 1000 g / eq.

  As the epoxy resin (B1), one type may be used alone, two or more types may be used in combination, and when two or more types are used in combination, their combination and ratio can be arbitrarily selected.

・ Thermosetting agent (B2)
The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1).
As a thermosetting agent (B2), the compound which has 2 or more of functional groups which can react with an epoxy group in 1 molecule is mentioned, for example. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxy group, a group in which an acid group has been anhydrideized, and the like, and a phenolic hydroxyl group, an amino group, or an acid group has been anhydrideized. It is preferably a group, more preferably a phenolic hydroxyl group or an amino group.

Among the thermosetting agents (B2), examples of the phenolic curing agent having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-based phenolic resins, and aralkylphenolic resins.
Among the thermosetting agents (B2), examples of the amine-based curing agent having an amino group include dicyandiamide (hereinafter sometimes abbreviated as “DICY”).

The thermosetting agent (B2) may have an unsaturated hydrocarbon group.
Examples of the thermosetting agent (B2) having an unsaturated hydrocarbon group include compounds in which a part of the hydroxyl group of the phenol resin is substituted with a group having an unsaturated hydrocarbon group, an aromatic ring of the phenol resin, Examples thereof include compounds in which a group having a saturated hydrocarbon group is directly bonded.
The unsaturated hydrocarbon group in the thermosetting agent (B2) is the same as the unsaturated hydrocarbon group in the epoxy resin having an unsaturated hydrocarbon group described above.

  When using a phenolic curing agent as the thermosetting agent (B2), it is preferable that the thermosetting agent (B2) has a high softening point or glass transition temperature in terms of improving the peelability of the protective film from the support sheet. .

The thermosetting agent (B2) is a solid that is solid at room temperature and does not exhibit curing activity with respect to the epoxy resin (B1), while being dissolved by heating and exhibits curing activity with respect to the epoxy resin (B1) It is preferably a curing agent (hereinafter sometimes abbreviated as “thermally active latent epoxy resin curing agent”).
The thermoactive latent epoxy resin curing agent is stably dispersed in the epoxy resin (B1) in the thermosetting protective film-forming film at room temperature, but is compatible with the epoxy resin (B1) by heating. Reacts with the epoxy resin (B1). By using the thermally active latent epoxy resin curing agent, the storage stability of the protective film-forming composite sheet is significantly improved. For example, the movement of the curing agent from the protective film-forming film to the adjacent support sheet is suppressed, and the thermosetting deterioration of the thermosetting protective film-forming film is effectively suppressed. And since the thermosetting degree by heating of the film for thermosetting protective film formation becomes higher, the pick-up property of the semiconductor chip with a protective film mentioned later improves more.

  Examples of the thermally active latent epoxy resin curing agent include onium salts, dibasic acid hydrazides, dicyandiamides, amine adducts of curing agents, and the like.

Among the thermosetting agents (B2), for example, the number average molecular weight of the resin component such as a polyfunctional phenol resin, a novolac-type phenol resin, a dicyclopentadiene-based phenol resin, an aralkyl phenol resin is preferably 300 to 30000, More preferably, 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 non-resin components such as biphenol and dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

  A thermosetting agent (B2) may be used individually by 1 type, may use 2 or more types together, and when using 2 or more types together, those combinations and ratios can be selected arbitrarily.

  In the protective film-forming composition (III-1) and the thermosetting protective film-forming film, the content of the thermosetting agent (B2) is 0. 0 parts by mass with respect to 100 parts by mass of the epoxy resin (B1). It is preferable that it is 1-500 mass parts, and it is more preferable that it is 1-200 mass parts. When the content of the thermosetting agent (B2) is equal to or higher than the lower limit value, the curing of the thermosetting protective film forming film more easily proceeds. Moreover, the moisture absorption rate of the film for thermosetting protective film formation was reduced because the said content of the thermosetting agent (B2) was below the said upper limit, and it was obtained using the composite sheet for protective film formation Improved package reliability.

  In the protective film-forming composition (III-1) and the thermosetting protective film-forming film, the content of the thermosetting component (B) (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2) The amount) is preferably 1 to 100 parts by mass, more preferably 1.5 to 85 parts by mass, and 2 to 70 parts by mass with respect to 100 parts by mass of the polymer component (A). It is particularly preferred that When the content of the thermosetting component (B) is in such a range, the adhesive force between the protective film and the support sheet is suppressed, and the peelability of the support sheet is improved.

[Curing accelerator (C)]
The protective film-forming composition (III-1) and the thermosetting protective film-forming film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of the protective film-forming composition (III-1).
Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol; 2-methylimidazole, 2-phenylimidazole Imidazoles such as 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole (one or more hydrogen atoms are other than hydrogen atoms) An imidazole substituted with a group of; an organic phosphine such as tributylphosphine, diphenylphosphine, triphenylphosphine (a phosphine having one or more hydrogen atoms substituted with an organic group); tetraphenylphosphonium tetraphenylborate Tetraphenyl boron salts such as triphenyl phosphine tetraphenyl borate and the like.

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

  When the curing accelerator (C) is used, the content of the curing accelerator (C) in the composition for forming a protective film (III-1) and the film for forming a thermosetting protective film is the thermosetting component (B). It is preferable that it is 0.01-10 mass parts with respect to 100 mass parts of content, and it is more preferable that it is 0.1-5 mass parts. The effect by using a hardening accelerator (C) is acquired more notably because the said content of a hardening accelerator (C) is more than the said lower limit. Moreover, since content of a hardening accelerator (C) is below the said upper limit, for example, a highly polar hardening accelerator (C) is in a film for thermosetting protective film formation under high temperature and high humidity conditions. In this case, the effect of suppressing the segregation by moving toward the adhesion interface with the adherend is increased, and the reliability of the package obtained using the composite sheet for forming a protective film is further improved.

[Filler (D)]
The protective film-forming composition (III-1) and the thermosetting protective film-forming film may contain a filler (D). When the thermosetting protective film-forming film contains the filler (D), the thermal expansion coefficient of the protective film obtained by curing the thermosetting protective film-forming film can be easily adjusted. And the reliability of the package obtained using the composite sheet for protective film formation improves more by optimizing this thermal expansion coefficient with respect to the formation object of a protective film. Moreover, the moisture absorption rate of a protective film can be reduced or heat dissipation can be improved because the film for thermosetting protective film formation contains a filler (D).

The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler.
Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, titanium white, bengara, silicon carbide, boron nitride, and the like; beads formed by spheroidizing these inorganic fillers; surface modification of these inorganic fillers Products; single crystal fibers of these inorganic fillers; glass fibers and the like.
Among these, the inorganic filler is preferably silica or alumina.

  The filler (D) contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one type, two or more types, or two or more types. Their combination and ratio can be arbitrarily selected.

  When the filler (D) is used, in the protective film forming composition (III-1), the ratio of the content of the filler (D) to the total content of all components other than the solvent (that is, thermosetting protection) The content of the filler (D) in the film-forming film is preferably 5 to 80% by mass, and more preferably 7 to 60% by mass. Adjustment of said thermal expansion coefficient becomes easier because content of a filler (D) is such a range.

[Coupling agent (E)]
The protective film-forming composition (III-1) and the thermosetting protective film-forming 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 thermosetting protective film-forming film to the adherend can be improved. it can. Moreover, by using the coupling agent (E), the protective film obtained by curing the thermosetting protective film-forming film has improved water resistance without impairing heat resistance.

The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional group of the polymer component (A), the thermosetting component (B), etc., and is preferably a silane coupling agent. More preferred.
Preferred examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-amino Ethylamino) propylmethyldiethoxysilane, 3- (phenylamino) propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropi Examples include trimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane. It is done.

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

  When the coupling agent (E) is used, the content of the coupling agent (E) in the composition for forming a protective film (III-1) and the film for forming a thermosetting protective film is such that the polymer component (A) and It is preferable that it is 0.03-20 mass parts with respect to 100 mass parts of total content of a thermosetting component (B), It is more preferable that it is 0.05-10 mass parts, 0.1-5 The part by mass is particularly preferred. When the content of the coupling agent (E) is equal to or more than the lower limit, the dispersibility of the filler (D) in the resin is improved, and the thermosetting protective film-forming film is adhered to the adherend. The effect by using a coupling agent (E), such as a property improvement, is acquired more notably. Moreover, generation | occurrence | production of an outgas is suppressed more because the said content of a coupling agent (E) is below the said upper limit.

[Crosslinking agent (F)]
As the polymer component (A), those having functional groups such as vinyl group, (meth) acryloyl group, amino group, hydroxyl group, carboxy group, isocyanate group and the like that can be bonded to other compounds such as the above-mentioned acrylic resin. When used, the protective film-forming composition (III-1) and the thermosetting protective film-forming film may contain a crosslinking agent (F). The crosslinking agent (F) is a component for bonding the functional group in the polymer component (A) with another compound to crosslink, and by crosslinking in this way, a film for forming a thermosetting protective film It is possible to adjust the initial adhesive force and cohesive force.

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

  Examples of the organic polyvalent isocyanate compound include an aromatic polyvalent isocyanate compound, an aliphatic polyvalent isocyanate compound, and an alicyclic polyvalent isocyanate compound (hereinafter, these compounds are collectively referred to as “aromatic polyvalent isocyanate compound and the like”). A trimer such as the aromatic polyisocyanate compound, isocyanurate and adduct; a terminal isocyanate urethane prepolymer obtained by reacting the aromatic polyvalent isocyanate compound and the polyol compound. Etc. The “adduct body” includes the aromatic polyisocyanate compound, the aliphatic polyisocyanate compound or the alicyclic polyisocyanate compound, and a low amount such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil. It means a reaction product with a molecularly active hydrogen-containing compound. Examples of the adduct include a xylylene diisocyanate adduct of trimethylolpropane as described later. The “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 Diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; trimethylol Any one of tolylene diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate is added to all or some hydroxyl groups of a polyol such as propane. Like lysine diisocyanate and the like; the compound or two or more are added.

  Examples of the organic polyvalent imine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, and tetramethylolmethane. -Tri-β-aziridinylpropionate, N, N′-toluene-2,4-bis (1-aziridinecarboxamide) triethylenemelamine 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, a reaction between the crosslinking agent (F) and the polymer component (A) results in a thermosetting protective film forming film. A crosslinked structure can be easily introduced.

  The crosslinking agent (F) contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one type, two or more types, or two or more types. Their combination and ratio can be arbitrarily selected.

When the crosslinking agent (F) is used, in the protective film-forming composition (III-1), the content of the crosslinking agent (F) is 0. 0 parts by mass relative to 100 parts by mass of the polymer component (A). It is preferably 01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass. The effect by using a crosslinking agent (F) is acquired more notably because the said content of a crosslinking agent (F) is more than the said lower limit. Moreover, because the content of the crosslinking agent (F) is not more than the upper limit value, the adhesive force with the support sheet of the thermosetting protective film forming film, the semiconductor wafer of the thermosetting protective film forming film, or It is suppressed that the adhesive force with a semiconductor chip falls too much.
In the present invention, the effects of the present invention can be sufficiently obtained without using the crosslinking agent (F).

[Energy ray curable resin (G)]
The protective film-forming composition (III-1) may contain an energy ray curable resin (G). Since the thermosetting protective film-forming film contains the energy ray-curable resin (G), the characteristics can be changed by irradiation with energy rays.

The energy beam curable resin (G) is obtained by polymerizing (curing) an energy beam curable compound.
Examples of the energy ray curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth) acryloyl group are preferable.

  Examples of the acrylate compound include trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxypenta ( Chain aliphatic skeleton-containing (meth) acrylates such as (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate; Cyclic aliphatic skeleton-containing (meth) acrylates such as cyclopentanyl di (meth) acrylate; polyalkylene glycol (meth) acrylates such as polyethylene glycol di (meth) acrylate; Rigoesuteru (meth) acrylate; urethane (meth) acrylate oligomer, epoxy-modified (meth) acrylate; the polyalkylene glycol (meth) Polyether (meth) acrylates other than the acrylates; itaconic acid oligomer, and the like.

  The energy ray curable compound preferably has a weight average molecular weight of 100 to 30,000, and more preferably 300 to 10,000.

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

  The energy ray curable resin (G) contained in the protective film-forming composition (III-1) may be only one type, two or more types, and when two or more types, the combination and ratio thereof are as follows. Can be arbitrarily selected.

  When using energy-beam curable resin (G), it is preferable that content of energy-beam curable resin (G) of composition (III-1) for protective film formation is 1-95 mass%, More preferably, it is 90 mass%, and it is especially preferable that it is 3-85 mass%.

[Photopolymerization initiator (H)]
When the protective film-forming composition (III-1) contains the energy beam curable resin (G), the photopolymerization initiator (H ) May be contained.

  Examples of the photopolymerization initiator (H) in the protective film-forming composition (III-1) include the same photopolymerization initiator as in the pressure-sensitive adhesive composition (ii).

  Only 1 type may be sufficient as the photoinitiator (H) which the composition for protective film formation (III-1) contains, and when it is 2 or more types, those combinations and ratios are arbitrary. Can be selected.

  In the case of using the photopolymerization initiator (H), in the protective film-forming composition (III-1), the content of the photopolymerization initiator (H) is 100 parts by mass of the energy ray curable resin (G). Is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and particularly preferably 2 to 5 parts by mass.

[Colorant (I)]
The protective film-forming composition (III-1) and the thermosetting protective film-forming film may contain a colorant (I).
Examples of the colorant (I) include known pigments such as inorganic pigments, organic pigments, and organic dyes.

  Examples of the organic pigments and organic dyes include aminium dyes, cyanine dyes, merocyanine dyes, croconium dyes, squalium dyes, azurenium dyes, polymethine dyes, naphthoquinone dyes, pyrylium dyes, and phthalocyanines. Dyes, naphthalocyanine dyes, naphtholactam dyes, azo dyes, condensed azo dyes, indigo dyes, perinone dyes, perylene dyes, dioxazine dyes, quinacridone dyes, isoindolinone dyes, quinophthalone dyes , Pyrrole dyes, thioindigo dyes, metal complex dyes (metal complex dyes), dithiol metal complex dyes, indolephenol dyes, triallylmethane dyes, anthraquinone dyes, dioxazine dyes, naphthol dyes, azomethine dyes Pigment Benzimidazolone dyes, pyranthrone pigments and threne color like.

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

  The colorant (I) contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one type, two or more types, or two or more types. Their combination and ratio can be arbitrarily selected.

  When using the colorant (I), the content of the colorant (I) in the thermosetting protective film-forming film may be appropriately adjusted according to the purpose. For example, the protective film may be printed by laser irradiation, adjusting the content of the colorant (I) of the thermosetting protective film-forming film, and adjusting the light transmittance of the protective film, Print visibility can be adjusted. Further, by adjusting the content of the colorant (I) in the thermosetting protective film-forming film, it is possible to improve the design of the protective film or make it difficult to see the grinding marks on the back surface of the semiconductor wafer. In consideration of this point, in the protective film forming composition (III-1), the ratio of the content of the colorant (I) to the total content of all components other than the solvent (that is, thermosetting protective film formation) The content of the colorant (I) of the film for use in the film is preferably 0.1 to 10% by mass, more preferably 0.1 to 7.5% by mass, and 0.1 to 5% by mass. It is particularly preferable that it may be, for example, either 0.1 to 3% by mass or 0.1 to 1% by mass. When the content of the colorant (I) is equal to or more than the lower limit value, the effect of using the colorant (I) is more remarkably obtained. Moreover, the excessive fall of the light transmittance of the film for thermosetting protective film formation is suppressed because the said content of a coloring agent (I) is below the said upper limit.

[General-purpose additive (J)]
The composition for forming a protective film (III-1) and the film for forming a thermosetting protective film may contain a general-purpose additive (J) as long as the effects of the present invention are not impaired.
The general-purpose additive (J) may be a known one, and can be arbitrarily selected according to the purpose, and is not particularly limited. Is mentioned.

The general-purpose additive (I) contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one type, two or more types, or two or more types. These combinations and ratios can be arbitrarily selected.
The content of the general-purpose additive (I) in the protective film-forming composition (III-1) and the thermosetting protective film-forming film is not particularly limited, and may be appropriately selected depending on the purpose.

[solvent]
The protective film-forming composition (III-1) preferably further contains a solvent. The protective film-forming composition (III-1) containing a solvent has good handleability.
The solvent is not particularly limited.
Preferred examples of the solvent include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol) and 1-butanol; ethyl acetate, butyl acetate and the like. Esters; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone.
Only 1 type may be sufficient as the solvent which the composition for protective film formation (III-1) contains, and when it is 2 or more types, when they are 2 or more types, those combinations and ratios can be selected arbitrarily.

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

<< Method for Producing Thermosetting Protective Film Forming Composition >>
A composition for forming a thermosetting protective film such as the composition for forming a protective film (III-1) can be obtained by blending each component for constituting the composition.
The order of addition at the time of blending each component is not particularly limited, and two or more components may be added simultaneously.
When a solvent is used, it may be used by mixing the solvent with any compounding component other than the solvent and diluting the compounding component in advance, or by diluting any compounding component other than the solvent in advance. You may use it by mixing a solvent with these compounding ingredients, without leaving.
The method of mixing each component at the time of compounding is not particularly limited, from a known method such as a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by applying ultrasonic waves What is necessary is just to select suitably.
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 adjusted as appropriate, but the temperature is preferably 15 to 30 ° C.

-Film for forming an energy beam curable protective film The film for forming an energy beam curable protective film contains an energy beam curable component (a).
The energy ray curable component (a) is preferably uncured, preferably tacky, and more preferably uncured and tacky. Here, “energy beam” and “energy beam curability” are as described above.

<< Energy ray-curable protective film-forming composition >>
The film for forming an energy ray curable protective film can be formed using the composition for forming an energy ray curable protective film containing the constituent material. For example, the energy ray curable protective film is applied to the target surface of the film for forming the energy ray curable protective film, and the energy ray curable protection is applied to the target site by applying the composition for forming the energy ray curable protective film and drying it as necessary. A film-forming film can be formed. In the composition for forming an energy ray-curable protective film, the ratio of the contents of components that do not vaporize at room temperature is usually the same as the ratio of the contents of the components of the film for forming an energy ray-curable protective film. . Here, “normal temperature” is as described above.

  Application of the energy ray curable protective film-forming composition may be performed by a known method, for example, an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater. And a method using various coaters such as a knife coater, a screen coater, a Meyer bar coater, and a kiss coater.

  Although the drying conditions of the composition for forming an energy ray-curable protective film are not particularly limited, it is preferable that the composition for forming an energy beam-curable protective film is dried by heating when it contains a solvent described later. The composition for forming an energy ray-curable protective film containing a solvent is preferably dried, for example, at 70 to 130 ° C. for 10 seconds to 5 minutes.

<Composition for forming protective film (IV-1)>
As the composition for forming an energy beam curable protective film, for example, the composition for forming an energy beam curable protective film (IV-1) containing the energy beam curable component (a) (in this specification, simply And “protective film-forming composition (IV-1)”).

[Energy ray curable component (a)]
The energy ray curable component (a) is a component that is cured by irradiation with energy rays, and is also a component for imparting film forming property, flexibility, and the like to the energy ray curable protective film forming film.
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 an energy ray curable group and a molecular weight of 100 to 80000. A compound (a2) is mentioned. The polymer (a1) may be crosslinked at least partly with a crosslinking agent or may not be crosslinked.

(Polymer (a1) having an energy ray curable group and having a weight average molecular weight of 80,000 to 2,000,000)
Examples of the polymer (a1) having an energy ray-curable group and having a weight average molecular weight of 80,000 to 2,000,000 include an acrylic polymer (a11) having a functional group capable of reacting with a group of another compound, An acrylic resin (a1-1) formed by addition reaction of a functional group reactive group and an energy ray curable compound (a12) having an energy ray curable group such as an energy ray curable double bond. It is done.

Examples of the functional group capable of reacting with a group possessed by another compound include a hydroxyl group, a carboxy group, an amino group, and a substituted amino group (one or two hydrogen atoms of the amino group are substituted with a group other than a hydrogen atom). Group), an epoxy group, and the like. However, the functional group is preferably a group other than a carboxy group from the viewpoint of preventing corrosion of a circuit such as a semiconductor wafer or a semiconductor chip.
Among these, the functional group is preferably a hydroxyl group.

-Acrylic polymer having a functional group (a11)
Examples of the acrylic polymer (a11) having the 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 monomers, monomers other than acrylic monomers (non-acrylic monomers) may be copolymerized.
The acrylic polymer (a11) may be a random copolymer or a block copolymer.

  Examples of the acrylic monomer having a functional group include a hydroxyl group-containing monomer, a carboxy 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, (meth) Hydroxyalkyl (meth) acrylates such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate; non- (meth) acrylic polymers such as vinyl alcohol and allyl alcohol Saturated alcohol (unsaturated alcohol which does not have a (meth) acryloyl skeleton) etc. are 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; fumaric acid, itaconic acid, maleic acid, citracone Examples include ethylenically unsaturated dicarboxylic acids such as acids (dicarboxylic acids having an ethylenically unsaturated bond); anhydrides of the ethylenically unsaturated dicarboxylic acids; and (meth) acrylic acid carboxyalkyl esters such as 2-carboxyethyl methacrylate. It is done.

  The acrylic monomer having a functional group is preferably a hydroxyl group-containing monomer or a carboxy group-containing monomer, more preferably a hydroxyl group-containing monomer.

  The acrylic monomer having the functional group that constitutes the acrylic polymer (a11) may be only one type, or two or more types, and when there are two or more types, the combination and ratio thereof are arbitrary. You can choose.

  Examples of the acrylic monomer having no functional group include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylate n. -Butyl, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, ( 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) Undecyl acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), (meth ) Tridecyl acrylate, tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate, ( Examples include (meth) acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester, such as octadecyl (meth) acrylate (stearyl (meth) acrylate), has a chain structure having 1 to 18 carbon atoms.

  Examples of the acrylic monomer having no functional group include alkoxy such as methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, and ethoxyethyl (meth) acrylate. Alkyl group-containing (meth) acrylic acid ester; (meth) acrylic acid aryl ester such as (meth) acrylic acid phenyl ester, etc .; (meth) acrylic acid ester having an aromatic group; non-crosslinkable (meth) acrylamide and Derivatives thereof: (meth) acrylic acid esters having a non-crosslinking tertiary amino group such as N, N-dimethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate are also included. .

  The acrylic monomer which does not have the functional group constituting the acrylic polymer (a11) may be only one type, or two or more types, and when there are two or more types, the combination and ratio thereof are arbitrary. Can be selected.

Examples of the non-acrylic monomer include olefins such as ethylene and norbornene; vinyl acetate; styrene.
The said non-acrylic monomer which comprises the said acrylic polymer (a11) may be only 1 type, may be 2 or more types, and when it is 2 or more types, those combinations and ratios can be selected arbitrarily.

  In the acrylic polymer (a11), the ratio (content) of the amount of the structural unit derived from the acrylic monomer having the functional group to the total amount of the structural unit constituting the polymer is 0.1 to 50 mass. %, More preferably 1 to 40% by mass, and particularly preferably 3 to 30% by mass. In the said acrylic resin (a1-1) obtained by copolymerization of the said acrylic polymer (a11) and the said energy-beam curable compound (a12) because the said ratio is such a range, it is energy. The content of the linear curable group can easily adjust the degree of curing of the protective film within a preferable range.

  1 type may be sufficient as the said acrylic polymer (a11) which comprises the said acrylic resin (a1-1), and when it is 2 or more types and they are 2 or more types, those combinations and ratios are arbitrary. You can choose.

  In the protective film-forming composition (IV-1), the content of the acrylic resin (a1-1) is preferably 1 to 40% by mass, more preferably 2 to 30% by mass. It is especially preferable that it is -20 mass%.

Energy beam curable compound (a12)
The energy ray curable compound (a12) is one or two selected from the group consisting of an isocyanate group, an epoxy group and a carboxy group as a group capable of reacting with the functional group of the acrylic polymer (a11). Those having the above are preferred, and those having an isocyanate group as the group are more preferred. For example, when the energy beam curable compound (a12) has an isocyanate group as the group, the isocyanate group easily reacts with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the functional group.

  The energy beam curable compound (a12) preferably has 1 to 5 energy beam curable groups in one molecule, and more preferably has 1 to 2 energy beam curable groups.

Examples of the energy ray curable compound (a12) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1- (bisacryloyloxymethyl). Ethyl isocyanate;
An acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth) acrylate;
Examples thereof include an acryloyl monoisocyanate compound obtained by a reaction of a diisocyanate compound or a polyisocyanate compound, a polyol compound, and hydroxyethyl (meth) acrylate.
Among these, it is preferable that the said energy-beam curable compound (a12) is 2-methacryloyloxyethyl isocyanate.

  The energy ray-curable compound (a12) constituting the acrylic resin (a1-1) may be only one type, or two or more types, and when there are two or more types, the combination and ratio thereof are arbitrary. Can be selected.

  In the acrylic resin (a1-1), the content of the energy ray curable group derived from the energy ray curable compound (a12) with respect to the content of the functional group derived from the acrylic polymer (a11). The ratio is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. When the ratio of the content is within such a range, the adhesive force of the protective film after curing is further increased. In addition, when the energy ray curable compound (a12) is a monofunctional compound (having one of the groups per molecule), the upper limit of the content ratio is 100 mol%, When the energy ray curable compound (a12) is a polyfunctional compound (having two or more of the groups in one molecule), the upper limit of the content ratio may exceed 100 mol%.

The polymer (a1) has a weight average molecular weight (Mw) of preferably 100,000 to 2,000,000, and more preferably 300,000 to 1500,000.
Here, the “weight average molecular weight” is as described above.

  In the case where the polymer (a1) is at least partially crosslinked by a crosslinking agent, the polymer (a1) has been described as constituting the acrylic polymer (a11). A monomer that does not correspond to any of the monomers and has a group that reacts with the crosslinking agent is polymerized to be crosslinked at the group that reacts with the crosslinking agent, or the energy ray-curable compound ( In the group which reacts with the functional group derived from a12), it may be crosslinked.

  The polymer (a1) contained in the protective film-forming composition (IV-1) and the energy ray-curable protective film-forming film may be one type, two or more types, or two or more types. In such a case, the combination and ratio thereof can be arbitrarily selected.

(Compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000)
Examples of the energy ray-curable group in the compound (a2) having an energy ray-curable group and having a molecular weight of 100 to 80,000 include a group containing an energy ray-curable double bond. ) An acryloyl group, a vinyl group, etc. are mentioned.

  The compound (a2) is not particularly limited as long as it satisfies the above conditions, but has a low molecular weight compound having an energy ray curable group, an epoxy resin having an energy ray curable group, and an energy ray curable group. A phenol resin etc. are mentioned.

Among the compounds (a2), examples of the low molecular weight compound having an energy ray curable group include polyfunctional monomers or oligomers, and an acrylate compound having a (meth) acryloyl group is preferable.
Examples of the acrylate compound include 2-hydroxy-3- (meth) acryloyloxypropyl methacrylate, polyethylene glycol di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, and 2,2-bis [4 -((Meth) acryloxypolyethoxy) phenyl] propane, ethoxylated bisphenol A di (meth) acrylate, 2,2-bis [4-((meth) acryloxydiethoxy) phenyl] propane, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene, 2,2-bis [4-((meth) acryloxypolypropoxy) phenyl] propane, tricyclodecane dimethanol di (meth) acrylate, 1 , 10-decanediol di (meth) acrylate 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (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) acrylic) Bifunctional (Roxyethoxy) phenyl] propane, neopentyl glycol di (meth) acrylate, ethoxylated polypropylene glycol di (meth) acrylate, 2-hydroxy-1,3-di (meth) acryloxypropane, etc. Data) acrylate;
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, dipentaerythritol poly (meth) acrylate, dipentaerythritol hexa ( Polyfunctional (meth) acrylates such as (meth) acrylate;
Examples include polyfunctional (meth) acrylate oligomers such as urethane (meth) acrylate oligomers.

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

  The weight average molecular weight of the compound (a2) is preferably 100 to 30000, and more preferably 300 to 10000.

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

[Polymer (b) having no energy ray curable group]
When the protective film-forming composition (IV-1) and the energy ray-curable protective film-forming film contain the compound (a2) as the energy ray-curable component (a), an energy ray-curable group is further added. It is also preferable to contain the polymer (b) that is not included.
The polymer (b) may be crosslinked at least partially by 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, or a copolymer of two or more acrylic monomers. Alternatively, it may be a copolymer of one or two or more acrylic monomers and a monomer (non-acrylic monomer) other than one or two or more acrylic monomers.

  Examples of the acrylic monomer constituting the acrylic polymer (b-1) include (meth) acrylic acid alkyl ester, (meth) acrylic acid ester having a cyclic skeleton, glycidyl group-containing (meth) acrylic acid ester, Examples include hydroxyl group-containing (meth) acrylic acid esters and substituted amino group-containing (meth) acrylic acid esters. Here, the “substituted amino group” is as described above.

  Examples of the (meth) acrylic acid alkyl ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylic acid n-. Butyl, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, (meth ) 2-ethylhexyl acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) acrylic Undecyl acid, dodecyl (meth) acrylate (lauryl (meth) acrylate), (meth ) Tridecyl acrylate, tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate, ( Examples include (meth) acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester, such as octadecyl (meth) acrylate (stearyl (meth) acrylate), has a chain structure having 1 to 18 carbon atoms.

Examples of the (meth) acrylic acid ester having a cyclic skeleton include (meth) acrylic acid cycloalkyl esters such as isobornyl (meth) acrylate and dicyclopentanyl (meth) acrylate;
(Meth) acrylic acid aralkyl esters such as (meth) acrylic acid benzyl;
(Meth) acrylic acid cycloalkenyl esters such as (meth) acrylic acid dicyclopentenyl ester;
Examples include (meth) acrylic acid cycloalkenyloxyalkyl esters such as (meth) acrylic acid dicyclopentenyloxyethyl ester.

Examples of the glycidyl group-containing (meth) acrylic 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. Examples include propyl, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like.
Examples of the substituted amino group-containing (meth) acrylic acid ester include N-methylaminoethyl (meth) acrylate.

  Examples of the non-acrylic monomer constituting the acrylic polymer (b-1) include olefins such as ethylene and norbornene; vinyl acetate; styrene.

Examples of the polymer (b) that is at least partially crosslinked by a crosslinking agent and does not have an energy ray-curable group include those in which a reactive functional group in the polymer (b) has reacted with a crosslinking agent. Can be mentioned.
The reactive functional group may be appropriately selected according to the type of the 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 carboxy group, and an amino group. Among these, a hydroxyl group having high reactivity with an isocyanate group is preferable. In addition, when the crosslinking agent is an epoxy compound, examples of the reactive functional group include a carboxy group, an amino group, an amide group, and the like. Among these, a carboxy group having high reactivity with an epoxy group is preferable. . However, the reactive functional group is preferably a group other than a carboxy group in terms of preventing corrosion of a circuit of a semiconductor wafer or a semiconductor chip.

  Examples of the polymer (b) having the reactive functional group and not having the energy ray-curable group include those obtained by polymerizing at least the monomer having the reactive functional group. In the case of the acrylic polymer (b-1), those having the reactive functional group as one or both of the acrylic monomer and the non-acrylic monomer mentioned as monomers constituting the polymer. Use it. 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. Examples thereof include those obtained by polymerizing a monomer in which one or two or more hydrogen atoms are substituted with the reactive functional group in a non-acrylic monomer or a non-acrylic monomer.

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

  The weight average molecular weight (Mw) of the polymer (b) having no energy ray curable group is 10,000 to 2,000,000 from the point that the film-forming property of the protective film-forming composition (IV-1) becomes better. It is preferable and it is more preferable that it is 100,000-1500,000. Here, the “weight average molecular weight” is as described above.

  The polymer (b) having no energy ray-curable group contained in the protective film-forming composition (IV-1) and the energy ray-curable protective film-forming film may be only one kind, or two or more kinds. However, when there are two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  Examples of the protective film-forming composition (IV-1) include those containing either one or both of the polymer (a1) and the compound (a2). And when the composition (IV-1) for protective film formation contains the said compound (a2), it is preferable to also contain the polymer (b) which does not have an energy-beam curable group further, in this case, It is also preferable to contain (a1). Moreover, the composition (IV-1) for forming a protective film does not contain the compound (a2), and contains both the polymer (a1) and the polymer (b) having no energy ray curable group. It may be.

  When the protective film-forming composition (IV-1) contains the polymer (a1), the compound (a2) and the polymer (b) having no energy ray-curable group, the protective film-forming composition In (IV-1), the content of the compound (a2) is 10 to 10 parts by mass with respect to 100 parts by mass of the total content of the polymer (a1) and the polymer (b) having no energy beam curable group. The amount is preferably 400 parts by mass, and more preferably 30 to 350 parts by mass.

  In the protective film-forming composition (IV-1), the total content of the energy beam curable component (a) and the polymer (b) having no energy beam curable group with respect to the total content of components other than the solvent. (Ie, the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group) of the energy ray-curable protective film-forming film) is 5 to 90% by mass. It is preferable that it is 10-80 mass%, and it is especially preferable that it is 20-70 mass%. When the ratio of the content of the energy ray curable component is within such a range, the energy ray curable film of the energy ray curable protective film forming film becomes more favorable.

  In addition to the energy ray curable component, the protective film-forming composition (IV-1) includes a thermosetting component, a photopolymerization initiator, a filler, a coupling agent, a crosslinking agent, a colorant, and a coloring agent. You may contain 1 type, or 2 or more types selected from the group which consists of a general purpose additive. For example, by using the protective film forming composition (IV-1) containing the energy ray curable component and the thermosetting component, the formed energy ray curable protective film forming film is deposited by heating. The adhesive force to the body is improved, and the strength of the protective film formed from this energy ray-curable protective film-forming film is also improved.

  As the thermosetting component, photopolymerization initiator, filler, coupling agent, cross-linking agent, colorant and general-purpose additive in the protective film-forming composition (IV-1), the protective film-forming composition, respectively. Thermosetting component (B), photopolymerization initiator (H), filler (D), coupling agent (E), crosslinking agent (F), colorant (I) and general-purpose additive in (III-1) The same thing as (J) is mentioned.

In the protective film-forming composition (IV-1), each of the thermosetting component, the photopolymerization initiator, the filler, the coupling agent, the crosslinking agent, the colorant, and the general-purpose additive is used alone. Alternatively, two or more types may be used in combination, and when two or more types are used in combination, their combination and ratio can be arbitrarily selected.
The contents of the thermosetting component, photopolymerization initiator, filler, coupling agent, crosslinking agent, colorant and general-purpose additive in the protective film-forming composition (IV-1) are appropriately adjusted according to the purpose. There is no particular limitation.

The protective film-forming composition (IV-1) preferably further contains a solvent since its handleability is improved by dilution.
Examples of the solvent contained in the protective film-forming composition (IV-1) include the same solvents as those in the protective film-forming composition (III-1).
Only 1 type may be sufficient as the solvent which the composition for protective film formation (IV-1) contains, and 2 or more types may be sufficient as it.

<< Method for producing composition for forming energy ray-curable protective film >>
The composition for forming an energy ray-curable protective film such as the protective film-forming composition (IV-1) can be obtained by blending each component for constituting the composition.
The order of addition at the time of blending each component is not particularly limited, and two or more components may be added simultaneously.
When a solvent is used, it may be used by mixing the solvent with any compounding component other than the solvent and diluting the compounding component in advance, or by diluting any compounding component other than the solvent in advance. You may use it by mixing a solvent with these compounding ingredients, without leaving.
The method of mixing each component at the time of compounding is not particularly limited, from a known method such as a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by applying ultrasonic waves What is necessary is just to select suitably.
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 adjusted as appropriate, but the temperature is preferably 15 to 30 ° C.

-Coating layer If the surface of the said coating layer on the opposite side to the side which is contacting the support sheet has surface roughness Ra smaller than the surface of the side provided with the coating layer of a support sheet, There is no particular limitation.
As the coating layer, for example, a coating containing a cured product obtained by curing by irradiation with energy rays is preferable, and a coating composition containing an energy beam polymerizable compound that is polymerized by irradiation with energy rays is cured. What was obtained was preferable. And it is preferable that the said energy-beam polymeric compound is (meth) acrylic acid or its derivative (s).

  The protective sheet-forming composite sheet has not only a function of forming a protective film for protecting the back surface of the semiconductor chip obtained by dicing, but also a function as a dicing sheet when dicing a semiconductor wafer, for example. It can be combined. When the semiconductor wafer is diced, the semiconductor wafer to which the protective film-forming composite sheet is attached may be expanded. In that case, the protective film-forming composite sheet is required to have appropriate flexibility. In order to impart appropriate flexibility to the composite sheet for forming a protective film, for example, a flexible resin such as polypropylene may be selected as a material constituting the support sheet. On the other hand, such a flexible resin may be deformed by heating or may have wrinkles. Therefore, it can be said that the coating layer is preferably one that can be formed by curing the composition as a raw material not by heat curing but by irradiation with energy rays.

The thickness of the coating layer is not particularly limited, but is preferably 0.1 to 20 μm, more preferably 0.4 to 15 μm, and particularly preferably 0.8 to 10 μm. When the thickness of the coating layer is equal to or more than the lower limit value, it becomes easier to reduce the surface roughness Ra on the surface of the coating layer opposite to the side in contact with the support sheet. The effect of suppressing blocking of the forming composite sheet is further increased. In addition, when the thickness of the coating layer is equal to or less than the upper limit value, the state of the semiconductor wafer after the protective film-forming composite sheet is pasted is examined by an infrared camera or the like through the sheet. A clearer inspection image can be acquired, and further, dicing of the semiconductor wafer with expansion can be performed more easily.
The coating layer covers the uneven surface of the support sheet as described above, so that the contact surface with the support sheet can be an uneven surface, but the thickness of the coating layer is the convex portion on the uneven surface of the coating layer. In a region including, the tip of the convex portion can be calculated as one starting point.

The surface roughness Ra on the surface of the coating layer opposite to the side in contact with the support sheet is preferably 0.5 μm or less, more preferably 0.4 μm or less, and 0.3 μm. More preferably, it is more preferably 0.2 μm or less. When the surface roughness Ra of the coating layer is not more than the upper limit value, laser printing can be performed more clearly on the protective film.
Moreover, the lower limit value of the surface roughness Ra on the surface of the coating layer on the side opposite to the side in contact with the support sheet is not particularly limited, but may be 0.005 μm, for example.
That is, the surface roughness Ra is, for example, preferably 0.005 to 0.5 μm, more preferably 0.005 to 0.4 μm, still more preferably 0.005 to 0.3 μm, particularly preferably 0.005. It can be 0.2 μm or less.
The surface roughness Ra of the coating layer is, for example, the surface roughness Ra of the surface of the support sheet provided with the coating layer, the thickness of the coating layer, and the application of a coating composition to be described later for forming the coating layer. It can be adjusted by the construction method.

  The coating layer has a value of [thickness of coating layer (μm)] / [surface roughness Ra (μm) of the surface of the support sheet provided with the coating layer] of 0.1 to 30. Is preferable, 0.3 to 20 is more preferable, and 0.5 to 10 is particularly preferable. When the value is equal to or more than the lower limit value, the surface roughness Ra on the surface of the coating layer opposite to the side in contact with the support sheet becomes smaller. Therefore, laser printing can be performed more clearly on the protective film, and the effect of suppressing blocking of the protective film-forming composite sheet is further enhanced. Moreover, it is avoided that the thickness of a coating layer becomes excessive because the said value is below the said upper limit.

The gloss value of the surface of the coating layer opposite to the side in contact with the support sheet (the support sheet side) is preferably 32-95, more preferably 40-90, 45 It is especially preferable that it is -85, for example, 50-80 may be sufficient. When the gloss value of the coating layer is in such a range, laser printing can be performed more clearly on the protective film. Furthermore, when the gloss value of the coating layer is equal to or more than the lower limit value, the state of the semiconductor wafer after the protective film-forming composite sheet is pasted is inspected with an infrared camera or the like through the sheet. A clearer inspection image can be acquired. And since the gloss value of the coating layer is less than or equal to the upper limit value, the phenomenon that the coating layer shines is similarly suppressed when inspecting the state of the semiconductor wafer, and the inspection image can be more visually recognized by an infrared camera or the like. It becomes easy.
The gloss value is a value obtained by measuring the 20 ° specular gloss of the surface of the coating layer from the side opposite to the support sheet side of the coating layer in accordance with JIS K 7105.

The measured value of haze from the coating layer side of the composite sheet for forming a protective film is preferably 47% or less, more preferably 1 to 47%, further preferably 2 to 40%, 3 to 30% is particularly preferable. When the haze of the composite sheet for forming a protective film is less than or equal to the upper limit value, light scattering is suppressed, and laser printing can be performed more clearly on the protective film. Further, when the state of the semiconductor wafer after the protective film-forming composite sheet is attached is inspected with an infrared camera or the like through the sheet, a clearer inspection image can be acquired. Here, the measured value of the haze of the protective film-forming composite sheet was measured from the direction of the surface opposite to the side of the coating layer in contact with the support sheet in the protective film-forming composite sheet. Mean haze value.
The haze is a value obtained by measurement according to JIS K 7136.

Various characteristics such as the gloss value of the coating layer can be adjusted by, for example, the thickness of the coating layer, the components of the coating composition to be described later for forming the coating layer, and the like.
The measured value of the haze from the coating layer side of the protective film-forming composite sheet is, for example, the thickness of each layer constituting the protective film-forming composite sheet, such as a coating layer or a support sheet, for forming these layers. It can be adjusted by the components contained in the composition (for example, a coating composition described later).

<< Coating composition >>
The coating composition is either one or both of silica sol and silica fine particles to which a radical polymerizable unsaturated group-containing organic compound is bonded (α) (hereinafter sometimes abbreviated as “component (α)”). , One or more selected from the group consisting of a polyfunctional acrylate monomer and an acrylate prepolymer (β) (hereinafter sometimes abbreviated as “component (β)”) Is preferred.

[Component (α)]
The component (α) lowers the refractive index of the coating layer and lowers the curing shrinkage and the heat-and-humidity shrinkage of the protective film-forming composite sheet. This is to suppress the occurrence of curling in the sheet.

  Examples of the silica sol in the component (α) include colloidal silica in which silica fine particles are suspended in a colloidal state in an organic solvent such as alcohol or ether derived from ethylene glycol (cellosolve). The average particle diameter of the suspended silica fine particles is preferably 0.001 to 1 μm, and more preferably 0.03 to 0.05 μm.

The silica fine particles bonded with the radical polymerizable unsaturated group-containing organic compound in the component (α) are crosslinked and cured by irradiation with energy rays.
As the silica fine particles to which the radical polymerizable unsaturated group-containing organic compound is bonded, for example, a silanol group present on the surface of the silica fine particles reacts with a functional group in the radical polymerizable unsaturated group-containing organic compound. The average particle diameter of the silica fine particles is preferably 0.005 to 1 μm. The functional group in the radical polymerizable unsaturated group-containing organic compound is not particularly limited as long as it can react with the silanol group in the silica fine particles.

  Examples of the radical polymerizable unsaturated group-containing organic compound having the functional group include compounds represented by the following general formula (1).

（式中、Ｒ^１は水素原子又はメチル基であり；Ｒ^２はハロゲン原子又は下記式（２ａ）〜（２ｆ）のいずれかで表される基である。）

(In the formula, R ¹ is a hydrogen atom or a methyl group; R ² is a halogen atom or a group represented by any of the following formulas (2a) to (2f)).

Examples of the halogen atom in R ^2, for example, elemental chlorine, bromine atom, and an iodine atom.

  Preferred examples of the radical polymerizable unsaturated group-containing organic compound include (meth) acrylic acid, (meth) acrylic acid chloride, (meth) acrylic acid 2-isocyanatoethyl, (meth) acrylic acid glycidyl, ( Examples include 2,3-iminopropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (3- (meth) acryloyloxypropyl) trimethoxysilane, and the like.

  In this invention, the said radically polymerizable unsaturated group containing organic compound may be used individually by 1 type, and may use 2 or more types together.

  In the component (α), the silica fine particles to which the silica sol and the radical polymerizable unsaturated group-containing organic compound are bonded may be each one kind or two kinds or more.

  As the component (α), only silica sol may be used, or only silica fine particles combined with the radical polymerizable unsaturated group-containing organic compound may be used. The silica sol and the radical polymerizable unsaturated group-containing organic compound may be used. You may use together the silica fine particle which the compound couple | bonded.

The content of the component (α) of the coating composition is preferably selected according to the refractive index of the support sheet, but usually the content of silica derived from the component (α) of the coating layer is 20. The amount is preferably 60% by mass. When the content of silica is not less than the lower limit, the effect of reducing the refractive index of the coating layer and the effect of suppressing the occurrence of curling in the protective film-forming composite sheet are further enhanced. Moreover, while the said content of a silica is below the said upper limit, while the formation of a coating layer becomes easier, the effect which suppresses the fall of the hardness of a coating layer becomes higher.
The content of silica derived from the component (α) of the coating layer because the refractive index of the coating layer, ease of formation and hardness, and curling generation suppression in the composite sheet for forming a protective film become better. Is more preferably 20 to 45% by mass.

[Component (β)]
The component (β) is a main photocurable component that forms the coating layer.

The polyfunctional acrylate monomer in the component (β) is not particularly limited as long as it is a (meth) acrylic acid derivative having two or more (meth) acryloyl groups in one molecule.
Preferred examples of the polyfunctional acrylate monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di ( (Meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate phosphate, allylated cyclohexyl Di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipe Taerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol penta (meth) acrylate, propionic acid modified di Examples include pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate.

The acrylate prepolymer in the component (β) is not particularly limited as long as it is a polymer or oligomer that is a (meth) acrylic ester and has photocurability.
Preferred examples of the acrylate prepolymer include polyester acrylate prepolymer, epoxy acrylate prepolymer, urethane acrylate prepolymer, polyol acrylate prepolymer, and the like.

As the polyester acrylate prepolymer, for example, the hydroxyl group of a polyester oligomer having a hydroxyl group at both ends of a molecule obtained by condensation reaction of a polyvalent carboxylic acid and a polyhydric alcohol is esterified with (meth) acrylic acid. And those obtained by esterifying a hydroxyl group at the terminal of an oligomer obtained by addition reaction of an alkylene oxide with a polyvalent carboxylic acid with (meth) acrylic acid.
Examples of the epoxy acrylate prepolymer include those obtained by reacting an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolac type epoxy resin with (meth) acrylic acid for esterification. .
As said urethane acrylate type prepolymer, what is obtained by esterifying the polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol, and polyisocyanate with (meth) acrylic acid is mentioned, for example.
As said polyol acrylate type prepolymer, what is obtained by esterifying the hydroxyl group of polyether polyol with (meth) acrylic acid is mentioned, for example.

  In the component (β), each of the polyfunctional acrylate monomer and acrylate prepolymer may be one kind or two kinds or more.

  As the component (β), only the polyfunctional acrylate monomer may be used, or only the acrylate prepolymer may be used, and the polyfunctional acrylate monomer and acrylate prepolymer are used in combination. Also good.

[solvent]
The coating composition preferably further contains a solvent in addition to the component (α) and the component (β). When the coating composition contains a solvent, as will be described later, the coating composition can be applied and dried to form a coating film for forming the coating layer more easily.
The said solvent may be used individually by 1 type, and may use 2 or more types together.

  Examples of the solvent include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; methanol, ethanol, propanol, butanol, 1 -Alcohols such as methoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone and cyclohexanone; esters such as ethyl acetate and butyl acetate; cellosolves such as 2-ethoxyethanol (ethyl cellosolve) and the like.

[Optional ingredients]
In addition to the component (α) and the component (β), the coating composition has a monofunctional acrylate-based monomer, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, as long as the effects of the present invention are not impaired. Various optional components such as a crosslinking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a leveling agent, and an antifoaming agent may be contained.
The said arbitrary component may be used individually by 1 type, and may use 2 or more types together.

(Monofunctional acrylate monomer)
The monofunctional acrylate monomer as an optional component is a photocurable component and is not particularly limited as long as it is a (meth) acrylic acid derivative having only one (meth) acryloyl group in one molecule.
Preferred examples of the monofunctional acrylate monomer include cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), and octadecyl (meth) acrylate. (Stearyl (meth) acrylate), isobornyl (meth) acrylate and the like.

(Photopolymerization initiator)
As said photoinitiator as an arbitrary component, the well-known thing conventionally used with respect to radical polymerization is mentioned.
Preferred examples of the photopolymerization initiator include acetophenone compounds, benzophenone compounds, alkylaminobenzophenone compounds, benzyl compounds, benzoin compounds, benzoin ether compounds, benzyldimethylacetal compounds, benzoylbenzoate compounds, α -Aryl ketone photopolymerization initiators such as acyloxime ester compounds; sulfur-containing photopolymerization initiators such as sulfide compounds and thioxanthone compounds; acylphosphine oxide compounds such as acyl diarylphosphine oxides; anthraquinone compounds Can be mentioned.
In addition, when the said coating composition is hardened by irradiation of an electron beam, a photoinitiator is unnecessary.

  In the coating composition, the content of the photopolymerization initiator is preferably 0.2 to 10 parts by mass, and 0.5 to 7 parts by mass with respect to 100 parts by mass of the total content of the photocurable components. It is more preferable that

(Photosensitizer)
Examples of the photosensitizer include tertiary amines, p-dimethylaminobenzoate, and thiol sensitizers.
In the coating composition, the content of the photosensitizer is preferably 1 to 20 parts by mass, and preferably 2 to 10 parts by mass with respect to 100 parts by mass of the total content of the photocurable components. More preferred.

(Antioxidant, UV absorber, light stabilizer)
The antioxidant, the ultraviolet absorber and the light stabilizer may be known ones, but may be a reactive antioxidant having a (meth) acryloyl group in the molecule, an ultraviolet absorber and a light stabilizer. preferable. These antioxidants, UV absorbers and light stabilizers bind to the polymer chain formed by irradiation with energy rays, so that dissipation from the cured layer over time is suppressed, and the functions of these components over a long period of time. Is demonstrated.

The coating composition preferably contains a silica sol as the component (α), and more preferably contains a silica sol having an average particle size of silica fine particles suspended in a colloidal state of 0.03 to 0.05 μm. .
When the coating layer contains such a silica sol, the effect of suppressing blocking of the protective sheet-forming composite sheet is further enhanced. And, in the coating layer, such a silica sol is present more and more unevenly on the surface on the side opposite to the support sheet side and in the vicinity thereof than in other regions, thereby forming the protective film. The effect of suppressing the blocking of the composite sheet is further increased. In order to make the component components such as silica sol unevenly distributed in the coating layer, the coating conditions of the coating composition may be adjusted.

<< Method for producing coating composition >>
The coating composition is, for example, by blending energy ray polymerizable compounds such as the component (α) and the component (β) and other components for constituting the coating composition as necessary, other components. can get. A coating composition is obtained by the method similar to the case of the above-mentioned adhesive composition except the point from which a compounding component differs, for example.
When a solvent is used, it may be used by mixing the solvent with any compounding component other than the solvent and diluting the compounding component in advance, or by diluting any compounding component other than the solvent in advance. You may use it by mixing a solvent with these compounding ingredients, without leaving.
Components other than the solvent in the coating composition may be dissolved, or may be dispersed without dissolving. The concentration and viscosity of each component of the coating composition are not particularly limited as long as the coating composition can be applied.

◎ Method for Producing Protective Film Forming Composite Sheet A protective film forming composite sheet according to the present invention forms a protective film-forming film using the protective film-forming composition, and uses the coating composition to form a coating layer. Can be manufactured by laminating a coating layer, a support sheet, and a protective film-forming film in this order. When the support sheet is composed of a plurality of layers, the support sheet may be produced by laminating these layers. For example, when the support sheet is a laminate of a substrate and a pressure-sensitive adhesive layer, a pressure-sensitive adhesive layer may be formed using the pressure-sensitive adhesive composition.

The order of forming each layer (coating layer, support sheet, protective film forming film) constituting the protective film forming composite sheet is not particularly limited. Furthermore, the formation of each of these layers from the composition may be performed directly on the surface of the adjacent layer in the state of the protective sheet-forming composite sheet, or may be performed on this surface using a separate release film (release sheet). The formed layer may be bonded to the surface of the adjacent layer in the state of the protective film-forming composite sheet. However, in order to suppress the formation of voids between the coating layer and the uneven surface (back surface) of the support sheet, the coating layer is formed by coating the coating composition directly on the uneven surface of the support sheet. It is preferable.
Hereinafter, an example of the preferable manufacturing method of the composite sheet for protective film formation is demonstrated.

  The coating layer was formed as necessary by applying the coating composition to the uneven surface of the support sheet (in FIGS. 1 and 2, the back surface 10b of the support sheet 10, that is, the back surface 11b of the base material 11), and drying. It is preferably formed by curing the coating film.

  Coating of the coating composition on the target surface may be performed by a known method, for example, an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater. And a method using various coaters such as a screen coater, a Meyer bar coater, and a kiss coater.

When the coating composition is applied to the uneven surface of the support sheet, it is preferable to suppress the generation of voids between the coating layer and the uneven surface of the support sheet. By suppressing the generation of the voids, irregular reflection of light at the boundary between the coating layer and the uneven surface of the support sheet is suppressed, and laser printing can be performed more clearly on the surface of the protective film.
In order to suppress the generation of the voids, for example, it is preferable to use a coating composition having a low viscosity. Moreover, the coating composition containing an energy beam polymerizable compound is usually suitable for suppressing the generation of the voids.

  Although the drying conditions of a coating composition are not specifically limited, It is preferable to heat-dry a coating composition, and it is preferable to dry on the conditions for 0.5 to 5 minutes at 70-130 degreeC in this case, for example.

The curing conditions for the coating film formed from the coating composition are not particularly limited, and may be performed by a known method.
In the case of curing by irradiation with energy rays, for example, in the case of irradiation with ultraviolet rays, a high pressure mercury lamp, a fusion H lamp, a xenon lamp, a black light, an LED lamp or the like is used as the ultraviolet ray source, and the irradiation amount is preferably May be irradiated as 100 to 500 mJ / cm ² . On the other hand, in the case of irradiation with an electron beam, the electron beam is generated by an electron beam accelerator or the like, and the irradiation amount is preferably set to 150 to 350 kV. In particular, the coating layer is preferably formed by ultraviolet irradiation.

  For example, when the support sheet is formed by laminating the base material and the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is the surface of the base material provided with the coating layer (the surface 11a of the base material 11 in FIGS. 1 and 2). It can be formed by directly coating the pressure-sensitive adhesive composition. However, usually, for example, a pressure-sensitive adhesive layer formed by applying a pressure-sensitive adhesive composition to a release-treated surface of a release sheet and drying it is bonded to the surface of a substrate, and the release sheet is removed. It is preferable to adopt a method in which a layer is formed separately and this is bonded to the surface of the substrate.

  The pressure-sensitive adhesive composition can be applied to the target surface in the same manner as in the case of the coating composition.

  The applied pressure-sensitive adhesive composition may be cross-linked by heating, and the cross-linking by heating may also be performed for drying. The heating conditions can be, for example, 100 to 130 ° C. for 1 to 5 minutes, but are not limited thereto.

  When the support sheet is composed of one layer (single layer) such as a substrate only, or when the support sheet is composed of a plurality of layers, for example, a substrate and a pressure-sensitive adhesive layer are laminated. In any case, the composition for forming a protective film is directly applied to the surface of the support sheet provided with the coating layer (in FIGS. 1 and 2, the surface 10a of the support sheet 10, that is, the surface 12a of the pressure-sensitive adhesive layer 12). It is possible to form a protective film-forming film. However, normally, as in the case of the above-mentioned pressure-sensitive adhesive layer, the protective film-forming film formed by applying the protective film-forming composition to the release-treated surface of the release sheet and drying it is applied to the surface of the support sheet. It is preferable to adopt a method in which a protective film-forming film is separately formed and bonded to the surface of the support sheet, for example, such that the release sheet is removed if necessary.

The composition for forming a protective film can be applied to the target surface in the same manner as in the case of the coating composition.
Although the drying conditions of the composition for protective film formation are not specifically limited, It can be dried by the method similar to the case of a coating composition.

When the support sheet is formed by laminating the base material and the pressure-sensitive adhesive layer, the protective film-forming composite sheet according to the present invention can be produced by methods other than those described above. For example, a pressure-sensitive adhesive layer is formed using the pressure-sensitive adhesive composition, a protective film-forming film is formed using the protective film-forming composition, and then the pressure-sensitive adhesive layer and the protective film-forming film are overlapped. The surface of the base material (in FIGS. 1 and 2) provided with a coating layer on the surface of the pressure-sensitive adhesive layer of the laminated body (the surface on which the protective film-forming film of the pressure-sensitive adhesive layer is not provided). A composite sheet for forming a protective film can also be produced by laminating the surface 11a) of the substrate 11.
In this case, the conditions for forming the pressure-sensitive adhesive layer and the protective film-forming film are the same as in the above-described method.

  For example, when the protective film-forming composite sheet has a smaller surface area than the pressure-sensitive adhesive layer when the protective film-forming composite sheet is viewed from above and viewed in plan, as shown in FIG. In the manufacturing method described above, a protective film-forming film previously cut into a predetermined size and shape may be provided on the pressure-sensitive adhesive layer.

◎ Method of using composite sheet for forming protective film The method of using the composite sheet for forming a protective film according to the present invention is as follows, for example.
First, the usage method of the composite sheet for protective film formation in case the film for protective film formation is thermosetting is demonstrated.
In this case, first, the back surface of the semiconductor wafer is attached to the protective film forming film of the protective film forming composite sheet, and the protective film forming composite sheet is fixed to the dicing apparatus.
Next, the protective film-forming film is cured by heating to form a protective film. When a back grind tape is affixed to the surface (electrode formation surface) of the semiconductor wafer, the protective film is usually formed after removing the back grind tape from the semiconductor wafer.

  Next, the semiconductor wafer is diced into semiconductor chips. From the formation of the protective film to the time of dicing, printing can be performed on the surface of the protective film by irradiating the protective film with laser light from the coating layer side of the protective film-forming composite sheet. In this case, as described above, the surface roughness Ra of the surface (back surface) opposite to the side in contact with the support sheet of the coating layer is sufficiently small, and the back surface of the coating layer is smooth. It is a surface or a surface in which the degree of unevenness is suppressed. Therefore, when laser light is irradiated, irregular reflection of the laser light on the back surface of the coating layer is suppressed, and laser printing can be clearly performed on the protective film.

In addition, for the semiconductor wafer before dicing and the semiconductor chip obtained by dicing, by observing from the back surface (the surface on which the protective film-forming composite sheet is attached) side with an infrared camera or the like, The condition may be checked. For example, in the case of a semiconductor chip, the presence or absence of breakage such as chipping or cracking may be inspected.
On the other hand, in the semiconductor chip with a protective film according to the present invention, as described above, the surface roughness Ra of the surface (back surface) opposite to the side in contact with the support sheet of the coating layer is sufficiently small. Furthermore, the generation of voids is suppressed between the coating layer and the uneven surface (back surface) of the support sheet. Therefore, when a semiconductor wafer or a semiconductor chip is observed from the coating layer side through the protective film forming composite sheet with an infrared camera or the like, a clear inspection image can be obtained, so that the inspection can be performed with high accuracy. .

  Next, the semiconductor chip is peeled off from the support sheet together with the protective film stuck on the back surface thereof and picked up, thereby obtaining a semiconductor chip with a protective film. For example, when the support sheet is formed by laminating a base material and an adhesive layer, and the adhesive layer is energy ray curable, the adhesive layer is cured by irradiation of energy rays, A semiconductor chip with a protective film can be more easily obtained by picking up the semiconductor chip from the adhesive layer together with the protective film attached to the back surface thereof.

  For example, in the case of using the protective film forming composite sheet 1 shown in FIG. 1, the back surface of the semiconductor wafer is attached to the protective film forming film 13 of the protective film forming composite sheet 1 and the exposed support sheet 10 is exposed. (Adhesive layer 12) is affixed to a dicing jig (not shown) such as a ring frame to fix the protective film-forming composite sheet 1 to the dicing apparatus. Next, after the protective film forming film 13 is cured to form a protective film, laser printing is performed on the protective film, then dicing is performed, and energy beam irradiation is applied to the jig of the adhesive layer 12 as necessary. After curing the region other than the pasted portion, a semiconductor chip with a protective film may be picked up. As described above, when the protective film-forming composite sheet 1 in which the pressure-sensitive adhesive layer 12 is energy ray curable is used, the protective film-forming composite sheet 1 is not peeled off from the jig. It is necessary to adjust the specific area of the pressure-sensitive adhesive layer 12 so as not to be cured. On the other hand, when the composite sheet 1 for forming a protective film is used, there is no need to separately provide a configuration for attaching the composite sheet 1 to the jig.

  On the other hand, when the protective film forming composite sheet 2 shown in FIG. 2 is used, the back surface of the semiconductor wafer is attached to the protective film forming film 23 of the protective film forming composite sheet 2 and the jig bonding The agent layer 16 is attached to a dicing jig (not shown) such as a ring frame, and the protective film forming composite sheet 2 is fixed to a dicing apparatus. Next, after the protective film-forming film 23 is cured to form a protective film, laser printing is performed on the protective film, then dicing is performed, and if necessary, the adhesive layer 12 is cured by irradiation with energy rays, A semiconductor chip with a protective film may be picked up. Thus, when the protective film-forming composite sheet 2 in which the adhesive layer 12 is energy ray curable is used, the adhesive layer 12 is different from the case where the protective film-forming composite sheet 1 is used. It is not necessary to adjust so as not to cure the specific region. On the other hand, unlike the protective film-forming composite sheet 1, the protective film-forming composite sheet 2 is required to have a jig adhesive layer 16. By having the adhesive layer 16 for jig | tool, the thing of a wide composition can be selected as the adhesive layer 12 according to the objective.

Next, a method for using the composite sheet for forming a protective film when the protective film-forming film is energy ray curable will be described.
In this case, first, as in the case where the above-described protective film forming film is thermosetting, the back surface of the semiconductor wafer is attached to the protective film forming film of the protective film forming composite sheet, and the protective film is formed. Fix the composite sheet to the dicing machine.
Next, the protective film-forming film is cured by irradiation with energy rays to form a protective film. When a back grind tape is affixed to the surface (electrode formation surface) of the semiconductor wafer, the protective film is usually formed after removing the back grind tape from the semiconductor wafer.

  Next, the semiconductor wafer is diced into semiconductor chips. From the formation of the protective film to the time of dicing, printing can be performed on the surface of the protective film by irradiating the protective film with laser light from the coating layer side of the protective film-forming composite sheet. From this printing to dicing, it can be carried out in the same manner as the above-mentioned film for forming a protective film is thermosetting, and in that case, laser printing can be clearly performed on the protective film, Inspection can be performed with high accuracy by an infrared camera or the like.

Next, the semiconductor chip is peeled off from the support sheet together with the protective film stuck on the back surface thereof and picked up, thereby obtaining a semiconductor chip with a protective film.
This method is particularly suitable when, for example, a composite sheet for forming a protective film is used in which a support sheet is formed by laminating a base material and a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is non-energy ray curable. It is. Here, the case where the protective film-forming film is cured by irradiation with energy rays and then the semiconductor wafer is diced and a semiconductor chip with a protective film is picked up is described. However, the adhesive layer is a non-energy ray. When it is curable, the protective film-forming film can be cured by irradiation with energy rays at any stage until the semiconductor chip is picked up.

For example, when a support sheet is formed by laminating a base material and a pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer is an energy ray-curable composite sheet, a method described below is preferable. .
That is, first, as in the above case, the back surface of the semiconductor wafer is attached to the protective film forming film of the protective film forming composite sheet, and the protective film forming composite sheet is fixed to the dicing apparatus.
Next, the protective film is irradiated with laser light from the coating layer side of the protective film-forming composite sheet, printing is performed on the surface of the protective film, and the semiconductor wafer is diced into semiconductor chips. From this printing to dicing, it can be carried out in the same manner as the above-mentioned film for forming a protective film is thermosetting, and in that case, laser printing can be clearly performed on the protective film, Inspection can be performed with high accuracy by an infrared camera or the like.

  Next, by irradiating energy rays, the protective film-forming film is cured to form a protective film, and the adhesive layer is cured, and from this cured adhesive layer, the semiconductor chip is adhered to the back surface thereof By picking up with the film, a semiconductor chip with a protective film is obtained.

  On the other hand, when winding up a long protective film-forming composite sheet, the protective film usually has a release film (release film 15 in FIGS. 1 and 2) laminated on the exposed surface of the protective film-forming film. A film-forming composite sheet is used. The protective film-forming composite sheet according to the present invention has any configuration (for example, any of the protective film-forming composite sheet 1 shown in FIG. 1 and the protective film-forming composite sheet 2 shown in FIG. 2). Even if the protective sheet-forming composite sheet is wound into a roll, the lamination unit in which the coating layer, the support sheet, the protective film-forming film, and the release film are laminated in this order is sequentially formed in the radial direction of the roll. It will be stacked. As a result, between the laminated units that are in contact with each other in the radial direction of the roll, the surface of the release film of one laminated unit (the surface opposite to the side on which the protective film-forming film is provided), The back surface of the coating layer of the other laminated unit (the surface opposite to the side in contact with the base material) is in contact and pressed, and in this state, the roll of the protective film-forming composite sheet is Saved. However, the provision of the coating layer suppresses the sticking of the release film and the coating layer between the laminated units, so that the protective film-forming composite sheet according to the present invention is inhibited from blocking. The

  The composite sheet for protective film formation according to the present invention having a width of 50 mm and a length of 100 mm in a state in which a release film is provided on the protective film forming film, so that the coating layers are all directed in the same direction, and the total of the coating layers By stacking a plurality of sheets so as to have a thickness of 10 to 60 μm, one outermost layer is a coating layer and the other outermost layer is a release film, and this laminate is a composite sheet for forming a protective film The film was left to stand at 40 ° C. for 3 days while applying a force (external force) of 980.665 mN (ie, 100 gf) in the laminating direction, and then the release film closest to the outermost coating layer in the laminating direction was peeled off at a rate of 300 mm / Minute, at a peeling angle of 180 °, adjacent coating layers (the coating layer closest to the outermost coating layer in the stacking direction). The peeling force when peeled from the adhesive layer is preferably 10 mN / 50 mm or less, more preferably 7.5 mN / 50 mm or less, and particularly preferably 5 mN / 50 mm or less. Here, all the composite sheets for forming a protective film to be stacked are assumed to have the same configuration. Moreover, it is preferable that the number of the protective sheet-forming composite sheets to be stacked is ten. From the peeling force of such a release film, the height of the blocking suppression effect (blocking resistance) of the protective film-forming composite sheet according to the present invention can be confirmed.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the following examples.

<Manufacture of composite sheet for forming protective film>
[Example 1]
A composite sheet for forming a protective film having the structure shown in FIG. 1 was produced. A plan view of this protective film-forming composite sheet is shown in FIG. More specifically, it is as follows.

[Production of first laminate]
(Preparation of composition for forming thermosetting protective film)
The following components were blended in the following amounts (solid content), and methyl ethyl ketone was blended to obtain a protective film-forming composition (III-1) having a solid content concentration of 51% by mass.

(Polymer component (A))
(A) -1: acrylic resin (weight average) obtained by copolymerizing 10 parts by mass of n-butyl acrylate, 70 parts by mass of methyl acrylate, 5 parts by mass of glycidyl methacrylate and 15 parts by mass of 2-hydroxyethyl acrylate 150 parts by mass (thermosetting component (B))
・ Epoxy resin (B1)
(B1) -1: Bisphenol A type epoxy resin (“JER828” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 183 to 194 g / eq, molecular weight 370) 60 parts by mass (B1) -2: Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation) "JER1055", epoxy equivalent 800-900 g / eq, molecular weight 1600) 10 parts by mass (B1) -3: dicyclopentadiene type epoxy resin ("Epiclon HP-7200HH" manufactured by DIC, epoxy equivalent 274-286 g / eq) 30 Part by mass / thermosetting agent (B2)
(B2) -1: Dicyandiamide (solid dispersion type latent curing agent, “ADEKA HARDNER EH-3636AS” manufactured by ADEKA, 21 g / eq of active hydrogen) 2 parts by mass (curing accelerator (C))
(C) -1: 2 parts by mass (filler (D)) of 2-phenyl-4,5-dihydroxymethylimidazole (“Curesol 2PHZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.)
(D) -1: Silica filler (Admatex “SC2050MA”, surface-modified with an epoxy compound, average particle size 0.5 μm) 320 parts by mass (coupling agent (E))
(E) -1: γ-glycidoxypropyltrimethoxysilane (silane coupling agent, “KBM403” manufactured by Shin-Etsu Chemical Co., Ltd., methoxy equivalent 12.7 mmol / g, molecular weight 236.3) 0.4 parts by mass (coloring Agent (I))
(I) -1: Carbon black (pigment, “MA600B” manufactured by Mitsubishi Chemical Corporation, average particle size 28 nm) 1.2 parts by mass

(Formation of protective film-forming film, production of first laminate)
The composition for protective film formation (III-1) obtained above was applied onto the release-treated surface of the first release film (“SP-P502010 *” manufactured by Lintec Corporation, thickness 50 μm) using a knife coater. And dried at 120 ° C. for 2 minutes to form a protective film-forming film (thickness: 25 μm).
Next, on the surface opposite to the surface on which the first release film of the protective film forming film is provided, the release treatment surface of the second release film (“SP-PET 381031C”, thickness 38 μm, manufactured by Lintec) is provided. By sticking together, the elongate laminated body by which the 1st peeling film, the film for protective film formation, and the 2nd peeling film were laminated | stacked in this order was obtained. Then, after winding up this long laminated body to make a roll, this laminated body was 300 mm in the width direction (the width direction indicated by the symbol w ₁ of the protective film-forming composite sheet 1 shown in FIG. 3). Cut only the size.

And with respect to this cut laminated body, in the width direction center part, it draws a circle with a diameter of 220 mm in plan view from the second release film side to the second release film and the protective film forming film. A half cut was made to make a cut. In the present specification, the “plan view” of the stacked body means that the stacked body is looked down from above in the stacking direction. Then, the second release film and the protective film-forming film are removed from the laminate so as to leave only the circular portion formed by the half cut, and on the release treatment surface of the first release film, As a result, a first laminated body in which a circular protective film-forming film and a second release film were laminated in this order was obtained. Film for circular protective film formation in the first laminate, the protective film forming composite sheet 1 shown in FIG. 3, the diameter d ₁ corresponds to the protective film forming film 13 of a circular 220 mm.

(Preparation of coating composition)
150 parts by mass of a silica sol dispersed in 2-ethoxyethanol (ethyl cellosolve) (catalyst chemical industry "OSCAL 1632", silica sol particle size 30-50 nm, solid content concentration 30% by mass), urethane acrylate and A hard coating agent composed of a polyfunctional acrylate monomer ("Arakawa Chemical Industries" Beam Set 575CB ", solid content concentration 100% by weight, containing a photopolymerization initiator) 100 parts by weight, and coating composition (solid content concentration 30% by mass) was obtained.

(Formation of coating layer)
Next, a polypropylene substrate (thickness 100 μm, melting point 140 to 160 ° C.) having a surface roughness Ra of 0.4 μm on the uneven surface and a surface roughness Ra of 0.02 μm on the surface opposite to the uneven surface. After applying the coating composition obtained above to the uneven surface of the film using a Mayer bar coater, drying at 80 ° C. for 1 minute, and then irradiating with ultraviolet light at a light intensity of about 230 mJ / cm ² The coating film was cured to form a coating layer (thickness 3 μm).

(Preparation of adhesive composition)
100 parts by weight of (meth) acrylic acid alkyl ester copolymer and 10 parts by weight (solid content) of aromatic polyisocyanate compound (crosslinking agent, “Takenate D110N” manufactured by Mitsui Chemicals) are blended, and methyl ethyl ketone is further blended. Thus, a pressure-sensitive adhesive composition (iii) having a solid content concentration of 30% by mass was obtained.
The (meth) acrylic acid alkyl ester copolymer is formed by copolymerizing 40 parts by mass of n-butyl acrylate, 55 parts by mass of 2-ethylhexyl acrylate, and 5 parts by mass of 2-hydroxyethyl acrylate. 600,000 acrylic resin.

(Formation of pressure-sensitive adhesive layer (support sheet), production of second laminate)
A knife coater is applied to the release-treated surface of a third release film (“SP-PET381031C” manufactured by Lintec Corporation) made of a polyethylene terephthalate film having a thickness of 38 μm, one side of which is released by forming a silicone release agent layer. The pressure-sensitive adhesive composition (iii) obtained above was applied and dried to form a pressure-sensitive adhesive layer (thickness 5 μm).
Next, the surface of the above-mentioned base material on which the coating layer is formed is subjected to corona treatment on the surface opposite to the concavo-convex surface, and then the above-mentioned pressure-sensitive adhesive layer is bonded to this corona-treated surface to form a coating layer, base material, and adhesive. The agent layer and the third release film were laminated in this order to obtain a long second laminate including a support sheet.
Next, after winding the long second laminated body into a roll, the second laminated body is formed in the width direction (the width direction indicated by the symbol w ₁ of the protective sheet-forming composite sheet 1 shown in FIG. 3). ) Was cut by a size of 300 mm.

(Manufacture of composite sheet for protective film formation)
The 2nd peeling film was removed from the 1st laminated body obtained above, and the circular film for protective film formation was exposed. Moreover, the 3rd peeling film was removed from the 2nd laminated body obtained above, and the adhesive layer was exposed. Then, by bonding the exposed surface of the protective film forming film to the exposed surface of the adhesive layer, the coating layer, the base material, the adhesive layer, the protective film forming film, and the first release film are in this order. A third laminated body corresponding to the composite sheet for forming a protective film was obtained.

A half cut is performed on the third laminate obtained above from the coating layer side so as to draw a circle having a diameter of 270 mm in a plan view on all of the coating layer, the base material and the adhesive layer. It was. In this half-cut, the coating layer, the base material, and the pressure-sensitive adhesive layer are formed so that the circle having a diameter of 270 mm is concentric with the circle having a diameter of 220 mm formed by the protective film-forming film in plan view. Cut everything into cuts.
Next, in a plan view, the width of the third laminate (in the protective sheet-forming composite sheet 1 shown in FIG. 3 of the composite sheet 1 shown in FIG. 3) is 20 mm away from the circle having a diameter of 270 mm. so as to draw a pair of arcuate opposite in direction) of the width indicated by reference numeral w _1, was carried out from the coating layer side, a coating layer, a half-cut to put cuts in all substrates and the pressure-sensitive adhesive layer. The notches corresponding to the pair of arcs form a curved peripheral portion of the pressure-sensitive adhesive layer denoted by reference numeral 121 in the protective film-forming composite sheet 1 shown in FIG. Then, a circle with a diameter of 270 mm, the distance between the arc (20 mm) is in the protective film forming composite sheet 1 shown in FIG. 3, it corresponds to the code _{w 2.}

Such an above-mentioned half cut draw two concentric circles and a pair of arc, with respect to the direction of the longitudinal (width indicated by reference numeral w ₁ of the protective film forming composite sheet 1 shown in Figure 3 for the third stack The coating layer, the base material, and the substrate from the coating layer side so as to draw two straight lines connecting the arcs in the longitudinal direction between the adjacent portions in a plan view. A half cut was made to cut all the pressure-sensitive adhesive layer. The notches corresponding to the two straight lines form a planar peripheral edge of the pressure-sensitive adhesive layer indicated by reference numeral 122 in the protective film-forming composite sheet 1 shown in FIG.
Next, in a plan view, a coating layer, a base material, and an adhesive in a portion between the circle having a diameter of 270 mm and a pair of arcs, and a portion sandwiched by two straight lines connecting the arcs By removing the layer, the composite sheet for forming a protective film shown in FIGS. 1 and 3 was obtained. Circular pressure-sensitive adhesive layer in the composite sheet for forming a protective film (support sheet), in FIG. 3, the diameter d ₂ corresponds to the circular pressure-sensitive adhesive layer 12 (support sheet 10) of 270 mm. Moreover, the 1st peeling film in this composite sheet for protective film formation corresponds to the peeling film 15 in FIG.

[Example 2]
As shown in Table 1, a composite sheet for forming a protective film was obtained in the same manner as in Example 1 except that a substrate having a surface roughness Ra of the uneven surface of 1 μm instead of 0.4 μm was used.

[Example 3]
As shown in Table 1, the same as Example 1, except that a substrate having a surface roughness Ra of 1 μm instead of 0.4 μm was used, and the thickness of the coating layer was changed to 1 μm instead of 3 μm. By the method, a composite sheet for forming a protective film was obtained.

[Example 4]
As shown in Table 1, a composite sheet for forming a protective film was obtained in the same manner as in Example 1 except that the thickness of the coating layer was changed to 1 μm instead of 3 μm.

[Example 5]
As shown in Table 1, the same as Example 1 except that a substrate having a surface roughness Ra of 1 μm instead of 0.4 μm was used and the thickness of the coating layer was changed to 6 μm instead of 3 μm. By the method, a composite sheet for forming a protective film was obtained.

[Example 6]
As shown in Table 1, the same as Example 1 except that a substrate having a surface roughness Ra of 3 μm instead of 0.4 μm was used, and the thickness of the coating layer was changed to 6 μm instead of 3 μm. By the method, a composite sheet for forming a protective film was obtained.

[Comparative Example 1]
As shown in Table 1, a protective film was formed in the same manner as in Example 1 except that a substrate having a surface roughness Ra of 1 μm instead of 0.4 μm was used and a coating layer was not formed. A composite sheet was obtained.

[Comparative Example 2]
As shown in Table 1, the base material was arranged so that the uneven surface faced to the opposite side, that is, the pressure-sensitive adhesive layer side (inner side), and the coating layer was not formed (that is, the conventional configuration shown in FIG. Except for the points, a composite sheet for forming a protective film was obtained in the same manner as in Example 1.

[Comparative Example 3]
As shown in Table 1, a substrate having a surface roughness Ra of 1 μm instead of 0.4 μm is used, and this substrate is placed so that the surface of the uneven surface faces the opposite side, that is, the pressure-sensitive adhesive layer side (inner side). A composite sheet for forming a protective film was obtained in the same manner as in Example 1 except that the coating layer was not formed (that is, the conventional configuration shown in FIG. 5).

[Comparative Example 4]
Instead of the dispersion in which the silica sol is dispersed in 2-ethoxyethanol, the same amount of spherical silica surface-modified with an epoxy group (“Advertex“ SC2050MA ”, average particle size 0.5 μm) is used as the solid content. A coating composition was prepared in the same manner as in Example 1 except for the points used.
And the composite sheet for protective film formation was obtained by the same method as Example 1 except the point which used this coating composition.
In the obtained composite sheet for forming a protective film, the surface roughness Ra of the outermost surface on the substrate side was 0.8 μm as shown in Table 1.

<Evaluation of composite sheet for forming protective film>
[Laser printability]
In the composite sheet for protective film formation of each Example and Comparative Example obtained above, the first release film was removed, and a stainless steel ring frame was used using a sticking apparatus (“RAD-2700F / 12” manufactured by Lintec Corporation). While sticking an adhesive layer, the protective film formation film was stuck on the back surface of the silicon wafer (outer diameter 8 inches, thickness 100 micrometers) heated at 70 degreeC.
Next, the protective film-forming film was heat-treated at 130 ° C. for 2 hours, whereby the protective film-forming film was thermally cured to form a protective film.
Next, using a printing device (“VK9700” manufactured by KEYENCE, Inc.), a laser beam having a wavelength of 532 nm was irradiated from the substrate side to the protective film under the conditions of an output of 0.6 W, a frequency of 40 kHz, and a scanning speed of 100 mm / second. Then, laser printing was performed on the protective film with the following two patterns (pattern 1 and pattern 2).
(pattern)
Pattern 1: Character size 0.4 mm x 0.5 mm, character spacing 0.3 mm, number of characters 20
Pattern 2: Character size 0.2 mm x 0.5 mm, character spacing 0.3 mm, number of characters 20

Next, the visibility (laser printability) from the base material side of the characters formed on the protective film by the laser printing was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: All characters of patterns 1 and 2 were clear, and the characters of patterns 1 and 2 could be read without problems.
B: At least some characters were unclear in pattern 2, but all characters were clear in pattern 1, and the characters in pattern 1 could be read without problems.
C: In both patterns 1 and 2, at least some characters were unclear.

[Blocking resistance (1)]
The composite sheet for protective film formation of each Example and Comparative Example obtained above was wound around a 3-inch diameter ABS resin core with a length of 10 m, and left in this state at room temperature for 3 days.
Then, about the composite sheet for protective film formation of Examples 1-6 and Comparative Example 4, the lamination unit by which the coating layer, the base material, the adhesive layer, the film for protective film formation, and the 1st peeling film are laminated | stacked in this order. For the protective sheet-forming composite sheets of Comparative Examples 1 to 3, there are no coating layers, so the base material, the adhesive layer, the protective film-forming film, and the first release film are laminated in this order. Attempts to feed out the 10 laminated units, and at this time, if there was any sticking between the contact parts of the protective film forming composite sheet that were in contact with each other at the time of winding, and if there was sticking The degree was evaluated according to the following criteria. The results are shown in Table 1.
(Evaluation criteria)
A: No sticking between the contact portions was observed.
B: Although slight sticking between the contact portions was recognized, the composite sheet for forming a protective film could be fed out without any problem.
C: The contact portions were partly adhered to each other, and the first release film was peeled off from the pressure-sensitive adhesive layer when the protective film-forming composite sheet was fed out.

[Blocking resistance (2)]
The protective film-forming composite sheets obtained in the above examples and comparative examples were cut out to form a tape having a width of 50 mm and a length of 100 mm. When cutting out, the length direction of the tape was made to coincide with the application direction of the pressure-sensitive adhesive composition.
Ten tapes thus obtained were prepared, and these tapes were laminated to obtain test pieces. At this time, in Examples 1 to 6 and Comparative Example 4, the tapes were laminated so that the coating layer faced upward. And in the case of Comparative Examples 1-3, since the coating layer does not exist, in all, the said tape was laminated | stacked so that a base material might face upward. Next, the test piece is sandwiched between two glass plates (width 75 mm, length 15 mm, thickness 5 mm), and the entire laminate of the glass plate and the test piece is placed at a predetermined position with one glass plate as the lowermost layer. The test piece was pressurized by placing a weight on the other uppermost glass plate. At this time, the force applied to the test piece in the laminating direction of the tape was 980.665 mN (that is, 100 gf). In this state, the entire laminate of the glass plate and the test piece was stored at 40 ° C. for 3 days in a moist heat accelerator (manufactured by ESPEC), and a heating and pressing acceleration test was performed on the test piece.

Next, the test piece was taken out from the moist heat accelerator, and the lowermost first release film (the first release film in contact with the lowermost glass plate) and the protective film forming film adjacent thereto were removed and exposed. By sticking the pressure-sensitive adhesive layer to the support plate via a double-sided pressure-sensitive adhesive tape, only the lowermost first release film and the protective film-forming film adjacent thereto are removed from the test piece after the heat and pressure acceleration test. Was fixed to the support plate.
Next, in the case of Examples 1 to 6 and Comparative Example 4, among the above fixed ones, a laminate composed of the uppermost coating layer, the base material, the pressure-sensitive adhesive layer, and the protective film-forming film farthest from the support plate Things were removed, and the peeling force when the exposed first release film was peeled from the adjacent coating layer was measured using a tensile tester under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 °. In the case of Comparative Examples 1 to 3, among the above fixed ones, the laminate consisting of the uppermost base material, the adhesive layer and the protective film forming film farthest from the support plate is removed, and the exposed first peeling The peeling force when the film was peeled off from an adjacent substrate under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 ° was measured using a tensile tester. The measured value of the peeling force of the first release film thus obtained was used as an index of blocking resistance of the protective film-forming composite sheet.
In addition, when the peeling force of the 1st peeling film to be measured is sufficiently small, from the said test piece taken out from the moist heat accelerator, the lowermost 1st peeling film (lowermost glass plate and When trying to remove the protective film-forming film adjacent to the contacted first release film), the first release film, which is the target of measurement of the release force, first has its adjacent layer (Examples 1 to 6, In the case of the comparative example 4, it may peel from a coating layer, and in the case of the comparative examples 1-3, it may peel from. In that case, after removing the first release film of the lowermost layer from the test piece taken out from the wet heat accelerator, without removing the protective film forming film adjacent thereto, this protective film forming film, By sticking to a support plate via a double-sided adhesive tape, the one from which only the first release film of the lowermost layer is removed from the test piece is fixed to the support plate. The peel strength of the first release film was measured.
The results are shown in Table 1.

[Surface roughness Ra on the outermost surface of the substrate]
About the protective film-forming composite sheets of Examples 1 to 6 and Comparative Example 4 obtained above, the surface roughness Ra of the substrate-side outermost surface, that is, the surface opposite to the substrate side of the coating layer, Using a contact-type surface roughness meter (“SURFTEST SV-3000” manufactured by Mitutoyo Corporation), the cut-off value λc was 0.8 mm, the evaluation length Ln was 4 mm, and the measurement was performed according to JIS B0601: 2001. The results are shown in Table 1. In Table 1, for the protective film-forming composite sheets of Comparative Examples 1 to 3, as the surface roughness Ra of the substrate-side outermost surface, the surface roughness of the surface opposite to the adhesive layer side of the substrate described above Ra is described.

[Gloss value of coating layer surface]
About the composite sheet for protective film formation of Examples 1-6 and Comparative Example 4 obtained above, according to JIS K 7105, using a gloss meter (Nippon Denshoku Co., Ltd. gloss meter “VG 2000”) The 20 ° specular glossiness of the surface of the coating layer was measured from the side opposite to the substrate side, and the measured value was taken as the gloss value of the surface of the coating layer. The results are shown in Table 1.

[Measured value of haze from the coating layer side]
About the composite sheet for protective film formation of Examples 1-6 and Comparative Example 4 obtained above, according to JIS K 7136, using a haze meter (“NDH-2000” manufactured by Nippon Denshoku Industries Co., Ltd.), the coating layer side Haze was measured. The results are shown in Table 1.

The composite sheet for forming a protective film of Examples 1 to 6 was provided with a coating layer on the outermost layer on the base material side, so that both the laser printability and the blocking resistance were good.
In particular, the protective film-forming composite sheets of Examples 1, 2, 4, and 5 were superior in laser printability to the protective film-forming composite sheets of Examples 3 and 6, In the protective film forming composite sheets 4 and 5, the value of “[Thickness of coating layer (μm)] / [Surface roughness Ra (μm) of uneven surface of base material]” is larger. Since the relative thickness of the coating layer with respect to the surface roughness Ra of the uneven surface is larger, the surface roughness Ra (μm) of the substrate side outermost surface (surface opposite to the substrate side of the coating layer) is This is presumed to be due to the smaller size.
Moreover, the composite sheet for protective film formation of Examples 1-4 is excellent in blocking resistance than the composite sheet for protective film formation of Examples 5 and 6, and this is protective film formation of Examples 1-4. It is estimated that the composite sheet for use is because the thickness of the coating layer is thinner.
In addition, as for the composite sheet for protective film formation of Examples 1-6, the space | gap part was not recognized between all the base materials and the adhesive layer.

  On the other hand, the protective film-forming composite sheet of Comparative Example 1 has a surface (back surface) opposite to the surface (front surface) on the side having the adhesive layer of the base material, as shown in FIG. ) Is an uneven surface and does not have a coating layer, it was excellent in blocking resistance but inferior in laser printability.

  In the composite sheet for forming a protective film of Comparative Example 2, the surface (back surface) opposite to the surface (front surface) provided with the pressure-sensitive adhesive layer of the base material is a smooth surface, as shown in FIG. Although the laser printability was good because it was present and the coating layer was not provided, the blocking resistance was poor. The protective sheet-forming composite sheet of Comparative Example 3 also had the same configuration as the protective film-forming composite sheet of Comparative Example 2, but was inferior not only in blocking resistance but also in laser printability. This is presumed to be because the surface (surface) on the side having the pressure-sensitive adhesive layer of the base material is an uneven surface and the surface roughness Ra is larger than that of the protective sheet-forming composite sheet of Comparative Example 2. Is done. In Comparative Example 3, since the surface roughness Ra of the uneven surface is large, the shape of the uneven surface is reflected also on the surface of the protective film, and the degree of unevenness on the surface of the protective film is higher than in the case of Comparative Example 2. It is presumed that the larger the light, the greater the irregular reflection of light and the lower the laser printability. Furthermore, the protective sheet-forming composite sheets of Comparative Examples 2 and 3 both had voids between the uneven surface of the substrate and the pressure-sensitive adhesive layer, but Comparative Example 3 was more uneven than Comparative Example 2. Since the surface roughness Ra of the surface is large, the gap portion is large. Therefore, it is presumed that the comparative example 3 has a larger light irregular reflection than the comparative example 2 and the laser printability is inferior.

  The protective film-forming composite sheet of Comparative Example 4 is the same surface as the protective film-forming composite sheet of Example 1 (surface) opposite to the surface (front surface) provided with the pressure-sensitive adhesive layer. ) Is an uneven surface and has a coating layer, which is excellent in blocking resistance but inferior in laser printability. In the composite sheet for forming a protective film of Comparative Example 4, the substrate-side outermost surface (the surface opposite to the substrate side of the coating layer) is the surface on the side provided with the adhesive layer of the substrate ( This is presumably because the surface roughness Ra (μm) is larger than the surface (back surface) opposite to the front surface.

  The present invention can be used for manufacturing a semiconductor chip or the like whose back surface is protected by a protective film.

  DESCRIPTION OF SYMBOLS 1,2 ... Composite sheet for protective film formation, 10 ... Support sheet, 10a ... The surface of a support sheet, 10b ... The back surface of a support sheet, 11 ... Base material, 11a ... Base Material surface, 11b ... Back surface of substrate, 12 ... Adhesive layer, 12a ... Surface of adhesive layer, 13, 23 ... Protective film forming film, 13a, 23a ... Protection Surface of film forming film, 14 ... coating layer, 14a ... surface of coating layer, 14b ... back surface of coating layer, 15 ... release film, 15a ... surface of release film, 16. ..Jig adhesive layer, 16a ... Surface of jig adhesive layer

Claims (5)

A support sheet, a protective film-forming film on one surface of the support sheet, and a coating layer on the surface of the support sheet opposite to the side on which the protective film-forming film is provided. Become
The composite sheet for forming a protective film, wherein the surface of the coating layer opposite to the side in contact with the support sheet has a surface roughness Ra smaller than the surface of the support sheet on the side having the coating layer. . Furthermore, the peeling force of the said peeling film measured by the following method using the said composite film for protective film formation provided with the peeling film on the said film for protective film formation is 10 mN / 50mm or less, The Claim 1 Composite sheet for protective film formation.
(Measurement method of peel strength of release film)
The composite sheet for forming a protective film having a width of 50 mm and a length of 100 mm provided with a release film on the protective film-forming film, so that the coating layers are all directed in the same direction, and the total thickness of the coating layers Are laminated so that the outermost layer is a coating layer and the other outermost layer is a release film, and the laminate is laminated with the composite sheet for forming a protective film. The film was left to stand at 40 ° C. for 3 days while applying a force of 980.665 mN in the direction, and the release film closest to the outermost coating layer in the laminating direction was peeled off at 300 mm / min and at a peeling angle of 180 °. The peel force when peeled from the adjacent coating layer is measured. The support sheet is formed by laminating a base material and an adhesive layer,
The composite sheet for protective film formation according to claim 1 or 2, wherein the composite sheet for protective film formation is formed by laminating the coating layer, the substrate, the pressure-sensitive adhesive layer, and the film for protective film formation in this order.   The composite sheet for forming a protective film according to claim 3, wherein the pressure-sensitive adhesive layer is energy ray curable or non-energy ray curable.   The composite sheet for protective film formation as described in any one of Claims 1-4 whose said film for protective film formation is a thermosetting or energy-beam curable thing.

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