TWI783920B - Composite sheet for forming protective film - Google Patents

Abstract

A composite sheet for forming a protective film of the present invention includes a supporting sheet and a protective film forming film on one side of a surface of the supporting sheet and a coating layer on a surface opposite to the surface that is provided with the protective film forming film of the supporting sheet, wherein the surface roughness Ra of the surface opposite to the surface that contacts the supporting sheet of the coating layer is less than that of the surface that is provided with the coating layer of the suppoting sheet.

Description

Composite sheet for protective film formation

The present invention relates to a protective film forming composite sheet for forming a protective film on the back surface of a semiconductor wafer.

This application claims priority based on Japanese Patent Application No. 2016-042689 filed in Japan on March 4, 2016, and the content of this application is incorporated herein.

In recent years, semiconductor devices have been manufactured in the industry using a mounting method called a so-called face down method. In the flip-chip method, a semiconductor wafer having electrodes such as bumps on the circuit surface is used, and the electrodes are bonded to the substrate. Therefore, the back surface of the wafer, which is opposite to the circuit surface, may be exposed.

Sometimes a resin film made of organic material is formed as a protective film on the back surface of the bare wafer, and it is incorporated into a semiconductor device in the form of a semiconductor wafer with a protective film. The protective film is used to prevent chip cracking after the dicing step or packaging.

When forming this kind of protective film, use the protective film formation on the support sheet A composite sheet for forming a protective film with a film. As the support sheet, for example, a resin base material or a laminated structure of the base material and an adhesive layer is used, and the laminated surface of the protective film forming film of the base material or the adhesive layer is sometimes subjected to surface treatment. In the composite sheet for forming a protective film, the film for forming a protective film has the function of forming a protective film, and the support sheet can function as a dicing sheet. It can be said that the film for forming a protective film and the dicing sheet are integrally formed. A composite sheet for forming a protective film.

Usually, one side or both sides of the said base material before the processing of a support sheet have uneven|corrugated shape. The reason is that if the base material does not have such a concavo-convex shape, when the base material is wound up into a roll, the contact surfaces of the base materials adhere to each other to cause blocking (blocking), so that it is difficult to use. When at least one of the contact surfaces between the base materials has a concave-convex shape, the area of the contact surface becomes small, so that sticking is suppressed.

Typically, the conventional composite sheet for protective film formation using the base material which has such an uneven surface has a structure as shown in FIG. 4. Fig. 4 is a cross-sectional view schematically showing an example of a conventional composite sheet for forming a protective film. In addition, in the drawing used for the following description, for example, in order to understand the characteristics of the composite sheet for protective film formation easily, the part which becomes a main part may be enlarged and shown for convenience, and the size of each component is not limited. Ratio etc. are the same as actual.

The conventional protective film forming composite sheet 9 shown here is placed on the support sheet The film 13 for forming a protective film is provided on 90 , the support sheet 90 is constituted by a laminated structure of a base material 91 and an adhesive layer 12 , and the film 13 for forming a protective film is provided on the adhesive layer 12 . The film 13 for protective film formation becomes a protective film by hardening. The composite sheet 9 for protective film formation is further equipped with the release film 15 on the film 13 for protective film formation, and when using the composite sheet 9 for protective film formation, the release film 15 is removed. In the composite sheet 9 for forming a protective film, the surface (back surface) 90b of the support sheet 90 opposite to the surface (surface) 90a provided with the film 13 for forming a protective film, that is, the surface (back surface) 90b of the substrate 91 that is provided with the adhesive layer The surface (front surface) 91a of 12 is a surface (back surface) 91b on the opposite side, which is a concave-convex surface. When the composite sheet 9 for protective film formation makes the back surface 91b of the base material 91 into an uneven|corrugated surface in this way, when it winds up into a roll, blocking is suppressed. That is, the adhesion of the laminated composite sheets 9 for forming a protective film, more specifically, the adhesion between the back surface 91b of the substrate 91 and the exposed surface (surface) 15a of the release film 15 is suppressed.

On the other hand, for the composite sheet for protective film formation, printing may be performed by irradiating laser light on the surface of the support sheet side of the protective film formed of the film for protective film formation (hereinafter, sometimes referred to as "laser printing"). ). In laser printing, it irradiates from the side opposite to the side where the protective film was formed of the support sheet. At this time, for example, in the case of the composite sheet 9 for forming a protective film, the protective film is irradiated with laser light through the support sheet 90 from the back surface 91b side of the base material 91, but since the back surface 91b of the base material 91 is a concave-convex surface, the The light on the concave-convex surface will reflect diffusely, and there is a problem that the laser printing is not clear.

As a composite sheet for protective film formation which can prevent diffuse reflection of such light, the composite sheet 8 for protective film formation which has a structure as shown in FIG. 5 is known (for example, refer patent document 1). Fig. 5 is a cross-sectional view schematically showing another example of the conventional composite sheet for forming a protective film.

The conventional composite sheet 8 for forming a protective film shown here is similar to the composite sheet 9 for forming a protective film. The film 13 for forming a protective film is provided on a support sheet 80, and the support sheet 80 is composed of a base material 81 and an adhesive layer 12. A laminated structure comprising a protective film forming film 13 on the adhesive layer 12 . However, in the support sheet 80 , the arrangement of the concave-convex 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 a protective film, the surface (surface) 81a provided with the adhesive layer 12 of the base material 81 is a concave-convex surface, and the surface (back surface) 81b of the base material 81 opposite to the surface 81a is a smooth surface. Base material 81 , protective film forming film 13 , and release film 15 in support sheet 80 are the same as base material 91 , protective film forming film 13 , and release film 15 in 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 (surface) 80a provided with the adhesive layer 12 in the support sheet 80 becomes smooth. On the other hand, when the composite sheet 8 for forming a protective film is wound into a roll, the adhesion between the back surface 81b of the substrate 81 and the exposed surface (surface) 15a of the release film 15, that is, blocking, cannot be suppressed. If blocking occurs, wrinkles will be generated in the composite sheet 8 for protective film formation, and when the composite sheet 8 for protective film formation is rolled out from the roll, the peeling film 15 will be removed from the composite sheet 8 for protective film formation. The film 13 is peeled off. Furthermore, in order to eliminate the concave-convex shape, the adhesive layer 12 must have a sufficient thickness on the surface 81 a of the base material 81 . If the thickness of the adhesive layer 12 is not sufficient, there is a problem that the surface (back surface) 13b of the film 13 for forming a protective film on the support sheet 80 side has a concave-convex shape reflecting the concave-convex shape of the base material 81. The surface of the protective film formed by the film 13 for formation on the support sheet side was not clearly marked by laser printing applied thereto.

In this way, the actual situation is that there has been no composite sheet for forming a protective film that can achieve both the suppression of blocking and clear laser printing on the protective film.

[Prior Art Literature] [Patent Document]

Patent Document 1: Japanese Patent No. 5432853.

An object of the present invention is to provide a protective film-forming composite sheet for forming a protective film on the back surface of a semiconductor wafer, wherein the protective film-forming composite sheet can suppress sticking and can clearly perform laser printing on the protective film.

The present invention provides a composite sheet for forming a protective film, comprising a support sheet, a film for forming a protective film is provided on one surface of the support sheet, and a side of the support sheet opposite to the film for forming the protective film is provided. There is a coating on the surface; the part of the aforementioned coating that is in contact with the aforementioned supporting sheet The surface roughness Ra of the surface on the opposite side is smaller than the surface roughness Ra of the surface of the support sheet on the side provided with the coating layer.

In the composite sheet for forming a protective film of the present invention, the composite sheet for forming a protective film is further provided with a release film on the film for forming a protective film, and the peeling force of the release film measured by the following method may be 10 mN/50mm the following.

(Measuring method of peeling force of peeling film)

On the protective film forming composite sheet having a release film width of 50 mm and a length of 100 mm, a plurality of sheets are stacked so that all the coating layers face the same direction and the total thickness of the coating layers is 10 μm to 60 μm. In this way, a laminate in which one outermost layer is a coating layer and the other outermost layer is a release film is produced, and the aforementioned laminate is placed in a state where a force of 980.665 mN is applied in the lamination direction of the aforementioned protective film-forming composite sheet. After standing at 40°C for 3 days, the peeling film closest to the outermost coating in the lamination direction is peeled off from the adjacent coating at a peeling speed of 300mm/min and a peeling angle of 180°. The peel force at this time.

In the composite sheet for forming a protective film of the present invention, the support sheet may be formed by laminating the base material and the adhesive, and the composite sheet for forming the protective film may be formed by the coating, the base material, the adhesive layer, and the layer for forming the protective film. The membranes are sequentially laminated.

In the protective film forming composite sheet of the present invention, the adhesive layer may be an energy ray curable layer or a non-energy ray curable layer.

In the composite sheet for forming a protective film of the present invention, the film for forming a protective film may be a thermosetting layer or an energy ray curable layer.

The composite sheet for forming a protective film of the present invention is used to form a protective film on the back surface of a semiconductor wafer, and by using the composite sheet for forming a protective film, adhesion of the composite sheet for forming a protective film can be suppressed, and the protective film can be clearly observed. laser printing.

1, 2, 8, 9‧‧‧Composite sheet for protective film formation

10, 80, 90‧‧‧support sheet

10a, 80a, 90a‧‧‧The surface of the supporting sheet

10b, 80b, 90b‧‧‧The back of the support sheet

11, 81, 91‧‧‧substrate

11a, 81a, 91a‧‧‧The surface of the substrate

11b, 81b, 91b‧‧‧The back of the substrate

12‧‧‧adhesive layer

12a‧‧‧The surface of the adhesive layer

13.23‧‧‧Film for protective film formation

13a, 23a‧‧‧The surface of the protective film forming film

13b‧‧‧The back side of the protective film forming film

14‧‧‧Coating

14a‧‧‧coated surface

14b‧‧‧coated backside

15‧‧‧Peeling film

15a‧‧‧The surface of the release film

16‧‧‧adhesive layer for jig

16a‧‧‧The surface of the adhesive layer for jigs

121‧‧‧curved peripheral portion of the adhesive layer

122‧‧‧Planar Periphery of Adhesive Layer

d ₁ , d ₂ ‧‧‧diameter

w ₁ , w ₂ ‧‧‧width

Fig. 1 is a cross-sectional view schematically showing one embodiment of the protective film-forming composite sheet of the present invention.

Fig. 2 is a cross-sectional view schematically showing another embodiment of the composite sheet for forming a protective film of the present invention.

Fig. 3 is a plan view showing a composite sheet for forming a protective film produced in Examples.

Fig. 4 is a cross-sectional view schematically showing an example of a conventional composite sheet for forming a protective film.

Fig. 5 is a cross-sectional view schematically showing another example of the conventional composite sheet for forming a protective film.

◎Composite sheet for protective film formation

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

In the composite sheet for forming a protective film, the surface roughness Ra of the surface of the coating layer opposite to the side in contact with the support sheet is smaller than the surface roughness Ra of the surface of the support sheet provided with the coating layer Ra. That is, the surface of the coating layer on the opposite side to the side in contact with the support sheet is a smooth surface or a surface in which unevenness is suppressed. Therefore, when laser light is irradiated, diffuse reflection of laser light on the aforementioned surface having a small surface roughness Ra of the coating layer can be 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 side, laser printing can be clearly performed on the protective film.

Moreover, the coating layer in the said composite sheet for protective film formation is easy to slide moderately with respect to the contact thing with a coating layer, and has antistatic property. Therefore, when the composite sheet for protective film formation is wound up into a roll, the adhesion|attachment of the composite sheet for protective film formation laminated|stacked, that is, blocking, can be suppressed.

In addition, in the present specification, among the above-mentioned composite sheets for protective film formation, the film for protective film formation is hardened by heating or irradiation of energy rays to form a protective film, as long as the laminated structure of the aforementioned support sheet and protective film can be maintained. ,but It is called "composite sheet for protective film formation". In addition, in the aforementioned composite sheet for forming a protective film, when the aforementioned support sheet is a laminated structure of a base material and an adhesive layer, the sheet after hardening the adhesive layer can also maintain the relationship between the aforementioned base material and the adhesive layer. The laminated structure of the cured product, the film for forming a protective film, or the protective film is called a "composite sheet for forming a protective film".

Fig. 1 is a cross-sectional view schematically showing one embodiment of the protective film-forming composite sheet of 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 is provided on one surface 10a of the support sheet 10, and a film 13 is provided on the other surface (back surface) 10b of the support sheet 10. Coating14. Furthermore, the support sheet 10 is formed by laminating a base material 11 and an adhesive layer 12, the adhesive layer 12 is provided on one surface 11a of the base material 11, and the adhesive layer 12 is provided on the other surface (back surface) 11b of the base material 11. The coating layer 14 is provided with the film 13 for protective film formation on the adhesive layer 12 . Moreover, the composite sheet 1 for protective film formation is equipped with the release film 15 further on the film 13 for protective film formation, and when using the composite sheet 1 for protective film formation, the release film 15 is removed. The film 13 for protective film formation becomes a protective film by hardening.

In the composite sheet 1 for protective film formation, the adhesive layer 12 is laminated|stacked on the said surface 11a of the base material 11, and the film 13 for protective film formation is laminated|stacked on a part of the surface 12a of the adhesive layer 12. In addition, on the exposed surface of the surface 12a of the adhesive layer 12 where the protective film forming film 13 is not laminated, and the surface 13a (in other words, the upper surface and the side surface) of the protective film forming film 13, a peeling layer is laminated. From the membrane 15.

In addition, a gap part may exist between the peeling film 15 and the surface 12a of the adhesive layer 12, or the surface 13a of the film 13 for protective film formation. For example, the aforementioned voids are likely to be formed on the side surface of the protective film forming film 13 or in the vicinity of the protective film forming film 13 on the surface 12 a of the adhesive layer 12 .

In the composite sheet 1 for forming a protective film, the surface (back surface) 10b of the support sheet 10 opposite to the surface (surface) 10a provided with the film 13 for forming a protective film is a concave-convex surface. The surface (surface) 11a of the agent layer 12 is the opposite surface (rear surface) 11b to form a concave-convex surface. Further, the coating layer 14 is provided to cover the uneven surface. In the coating layer 14, the surface roughness Ra of the surface (back surface) 14b on the opposite side to the surface (surface) 14a in contact with the support sheet 10 (substrate 11) is smaller than that of the aforementioned back surface 10b of the support sheet 10 (in other words, the substrate 10). The surface roughness Ra of the aforementioned rear surface 11b) of 11. When performing laser printing on a protective film (not shown) formed of the film 13 for protective film formation, laser light is irradiated from the coating layer 14 side to the surface of the protective film on the support sheet 10 side. At this time, as described above, the surface roughness Ra of the back surface 14 b of the coating 14 becomes smaller, thereby suppressing diffuse reflection of the laser light on the coating 14 . Therefore, laser printing can be clearly performed on the protective film.

In addition, in this specification, "surface roughness Ra" means the so-called arithmetic mean roughness prescribed|regulated by JISB0601:2001 unless there is a notice especially.

Moreover, since the composite sheet 1 for protective film formation is equipped with the coating layer 14, it can suppress that the composite sheet 1 for protective film formation laminated|stacked mutually sticks, that is, sticks, even when it is wound up into a roll. More specifically, adhesion between the aforementioned back surface 11b of the substrate 11 and the exposed surface (surface) 15a of the release film 15 can be suppressed.

In the composite sheet 1 for protective film formation, although the surface 11a of the base material 11 becomes a smooth surface here, it may be the uneven surface with low smoothness. However, as will be described later, the base material 11 is preferable in that it is easier to suppress the generation of voids between the base material 11 and the adhesive layer 12, and to make the protective film forming composite sheet 1 have better characteristics. The surface 11a is a smooth surface.

When using the protective film forming composite sheet 1 shown in FIG. 1 , the release film 15 is removed, and the back surface of a semiconductor wafer (not shown) is attached to the surface 13 a of the protective film forming film 13 . Furthermore, the exposed surface which is not laminated|stacked the film 13 for protective film formation among the surface 12a of the adhesive layer 12 is stuck to jigs, 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 of the present invention. In addition, in FIG. 2, the same code|symbol as the case of FIG. 1 is attached|subjected to the same component shown in FIG. 1, and detailed description of this component is abbreviate|omitted. The same applies to the figures after FIG. 2 .

In the protective film forming composite sheet 2 shown here, in the adhesive layer The film 23 for protective film formation is layered on the entire surface 12a of 12, and the adhesive agent layer 16 for jigs is laminated|stacked on a part of the surface 23a of the film 23 for protective film formation. Furthermore, in the protective film forming composite sheet 2, the exposed surface of the jig adhesive layer 16 and the surface 16a of the jig adhesive layer 16 are not laminated on the surface 23a of the protective film forming film 23 (in other words, A release film 15 is laminated on the upper surface and the side surface. Except for these points, the composite sheet 2 for protective film formation is the same as the composite sheet 1 for protective film formation shown in FIG.

In addition, a gap part may exist between the peeling film 15 and the surface 23a of the film 23 for protective film formation, or the surface 16a of the adhesive agent layer 16 for jigs. For example, the aforementioned voids are likely to occur in the side surface of the jig adhesive layer 16 and in the vicinity of the jig adhesive layer 16 on the surface 23 a of the protective film forming film 23 .

In the composite sheet 2 for forming a protective film, as in the case of the composite sheet 1 for forming a protective film, the back surface 10b of the support sheet 10 (the back surface 11b of the base material 11 ) has an uneven surface, and the coating layer 14 covers the uneven surface. And set. Therefore, the surface roughness Ra of the aforementioned rear surface 14 b of the coating layer 14 is smaller than the surface roughness Ra of the aforementioned rear surface 10 b of the support sheet 10 . Therefore, laser printing can be clearly performed on the protective film formed from the film 23 for protective film formation.

Moreover, since the composite sheet 2 for protective film formation is equipped with the coating layer 14, it can suppress that the composite sheet 2 for protective film formation laminated|stacked mutually sticks, that is, sticks even when it is wound up into a roll.

When using the protective film forming composite sheet 2 shown in FIG. 2 , the release film 15 is removed, and the back surface of a semiconductor wafer (not shown) is attached to the surface 23 a of the protective film forming film 23 . In addition, the upper surface among the surface 16a of the adhesive agent layer 16 for jigs is stuck to jigs, such as a ring frame.

The protective film forming composite sheet of the present invention is not limited to the protective film forming composite sheet shown in FIGS. 1 to 2 , and the protective film shown in FIGS. Some configurations of the composite sheet for film formation are changed or deleted, or other configurations are further added to the composite sheet for protective film formation described above.

Hereinafter, each structure of the composite sheet for protective film formation of this invention is demonstrated in more detail.

○Support sheet

The said support sheet will not be specifically limited as long as the said film for protective film formation can be provided. Examples of the support sheet include a release sheet for preventing dust and the like from adhering to the surface of the protective film forming film, and a dicing sheet for protecting the surface of the protective film forming film in the dicing process and the like. The supporting film.

Preferred examples of the aforementioned support sheet include a support sheet composed of only a base material and a support sheet formed by laminating a base material and an adhesive, which are generally used in the field of semiconductor wafer processing sheets.

The support sheet may be composed of one layer (single layer), or may be composed of multiple layers of two or more layers. When the support sheet is composed of plural layers, these plural layers may be the same as or different from each other. That is, all layers may be the same, all layers may be different, or only some layers may be the same. Also, when the plural layers are different from each other, the combination of the plural layers is not particularly limited. Here, the plural layers are different from each other, which 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 can be appropriately selected according to the purpose, and laser printing can be performed on the protective film more clearly. In addition, sufficient flexibility can be given to the composite sheet for forming the protective film, and the adhesion to the semiconductor wafer can be improved. On the good side, it is preferably 10 μm to 500 μm, more preferably 20 μm to 350 μm, especially preferably 30 μm to 200 μm, for example, any one of 40 μm to 175 μm and 50 μm to 150 μm.

Here, the "thickness of the support sheet" means the total thickness of the layers constituting the support sheet. The total value of the layer thickness.

In addition, at least one side of the support sheet may be a concave-convex surface, and the thickness of the support sheet can be calculated at a portion including a convex portion on the concave-convex surface of the support sheet by taking the tip of the convex portion as a starting point.

‧Substrate

The material of the aforementioned base material is preferably various resins.

Specific examples of the aforementioned resins include: polyethylene (low-density polyethylene (LDPE; Low-density Polyethylene), linear low-density polyethylene (LLDPE; Linear Low-density Polyethylene), high-density polyethylene (HDPE; High -density Polyethylene, etc.)), polypropylene, ethylene-propylene copolymer, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyethylene terephthalate, poly Ethylene naphthalate, polybutylene terephthalate, polyurethane, polyacrylate urethane, polyimide, ethylene-vinyl acetate copolymer, ionomer resin, vinyl -(meth)acrylic acid copolymers, ethylene-(meth)acrylate copolymers, polystyrene, polycarbonate, fluororesins, and hydrogenated, modified, cross-linked or copolymerized products of any of these resins things etc.

In addition, in this specification, the concept of "(meth)acryl" includes both "acryl" and "methacryl".

In the case where the support sheet is formed of other lamination layers such as a base material and an adhesive layer, the thickness of the base material can be appropriately selected according to the purpose, preferably 15 μm to 300 μm, more preferably 20 μm to 200 μm, for example, 30 μm to 175 μm , any of 40 μm to 150 μm, and 50 μm to 125 μm. When the thickness of the base material is in such a range, the flexibility of the composite sheet for forming a protective film and the adhesiveness to a semiconductor wafer or a semiconductor wafer are further improved.

The substrate may be composed of one layer (single layer), or may be composed of multiple layers of two or more layers. When the base material is composed of multiple layers, these multiple layers can mutually The same or different. Here, "plurality of layers may be the same or different from each other" means the same meaning as in the case of the above-mentioned support sheet.

When the base material is composed of a plurality of layers, the total thickness of each layer may be the thickness of the above-mentioned preferable base material.

The surface roughness Ra of the surface (surface) provided with the adhesive layer in the substrate is preferably from 0.001 μm to 0.1 μm, more preferably from 0.005 μm to 0.08 μm, especially preferably from 0.01 μm to 0.04 μm. When the said surface roughness Ra of the base material surface is below the said upper limit, laser printing can be performed more clearly on a protective film.

The aforementioned 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.

Furthermore, as a method of singulating a semiconductor wafer into semiconductor wafers by dicing, for example, a method using the following dicing: blade dicing using a blade to cut into a semiconductor wafer, laser irradiation to cut into a semiconductor wafer Jet cutting, or water cutting that cuts into semiconductor wafers by blowing water containing abrasives, etc.

On the other hand, as a method of singulating a semiconductor wafer into semiconductor wafers, in addition to the above-mentioned dicing methods, the method of irradiating infrared region The laser light forms a modified layer inside the semiconductor wafer, and then exerts force on the semiconductor wafer, thereby dividing and singulating the semiconductor wafer at the part where the modified layer is formed.

When the above-mentioned surface roughness Ra of the substrate surface is, for example, 0.01 μm to 0.2 μm, the composite sheet for forming a protective film having such a substrate is preferably used to form a modified layer inside the semiconductor wafer and separate the semiconductor wafer. Used for circular singulation.

On the other hand, the surface roughness Ra of the surface (back surface) opposite to the surface (surface) provided with the adhesive layer in the substrate, in other words, the surface (surface) provided with the film for forming a protective film in the support sheet is The surface roughness Ra of the opposite side (back surface) is preferably 0.001 μm to 4 μm, more preferably 0.005 μm to 3.7 μm, further preferably 0.01 μm to 3.4 μm, and particularly preferably 0.02 μm to 3.1 μm. By making the aforementioned surface roughness Ra of the backside of the substrate below the aforementioned upper limit, it is easier to reduce the surface roughness Ra of the surface of the coating opposite to the side in contact with the support sheet, thereby making it easier to The protective film is clearly laser printed.

The above-mentioned surface roughness Ra of the back surface of the substrate can be adjusted by, for example, molding conditions of the substrate, surface treatment conditions of the substrate, and the like.

The resin used as the material of the base material may also be cross-linked.

In addition, the base material made of resin may be formed into a sheet by extrusion of a thermoplastic resin, stretched, or formed into a sheet by thinning and curing of a curable resin by known means.

In addition, the substrate can be colored or printed.

It is excellent in heat resistance and has elongation by having moderate flexibility In terms of good suitability and pick-up suitability, the base material preferably contains polypropylene.

The base material containing polypropylene may be, for example, a single-layer or multi-layer base material composed of only polypropylene, or a multi-layer (more than two layers) layer composed of a polypropylene layer and a resin layer other than polypropylene. Substrate.

When the film for forming a protective film is thermosetting, since the base material has heat resistance, the degradation of the base material due to heat can be suppressed, and it is possible to effectively suppress occurrence of defects in the manufacturing process of semiconductor devices.

In order to improve the adhesion between the base material and the adhesive layer or protective film forming film provided on the base material, the surface of the base material can also be subjected to roughening treatment such as sandblasting treatment, solvent treatment, etc.; corona discharge treatment, electronic Beam irradiation treatment, plasma treatment, ozone/ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment and other oxidation treatments. In addition, a primer treatment may be performed on the surface of the substrate.

‧Adhesive layer

A well-known adhesive layer can be used suitably for the said adhesive layer.

The adhesive layer can be formed using an adhesive composition that constitutes the adhesive layer and contains various components such as an adhesive. The content ratio of the components that do not vaporize at normal temperature in the adhesive composition is usually the same as the content ratio of the aforementioned components in the adhesive layer. Furthermore, in this specification, "normal temperature" means a temperature that is neither particularly cold nor particularly hot, that is, an ordinary temperature, for example, a temperature of 15° C. to 25° C. can be mentioned.

The thickness of the adhesive layer can be appropriately selected according to the purpose, preferably 1 μm to 100 μm, more preferably 2 μm to 80 μm, especially preferably 3 μm to 50 μm, for example, any one of 3 μm to 35 μm, 3 μm to 20 μm, and 3 μm to 10 μm .

The adhesive layer may consist of one layer (single layer), or may consist of multiple layers of two or more layers. When the adhesive layer is composed of plural layers, these plural layers may be the same as or different from each other. Here, "a plurality of layers may be the same as or different from each other" means the same meaning as in the case of the above-mentioned support sheet.

When the adhesive layer is composed of a plurality of layers, the total thickness of each layer may be the thickness of the above-mentioned preferred adhesive layer.

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

In addition, in this specification, the term "energy ray" means an electromagnetic wave or a charged particle beam having an energy quantum, and examples of the energy ray include ultraviolet rays, radiation rays, electron beams, and the like. Ultraviolet rays can be irradiated by using high-pressure mercury lamps, fusion (Fusion) H-type lamps, xenon lamps, black light lamps, or LED (Light Emitting Diode; Light Emitting Diode) lamps, etc. as ultraviolet light sources. shoot. The electron beam may be irradiated with an electron beam generated by an electron beam accelerator or the like.

In addition, in this specification, "energy ray curability" means the property of being cured by irradiation of energy ray, and "non-energy ray curability" means the property of not being cured even when irradiated with energy ray.

Examples of the aforementioned energy ray curable resin include resins having polymerizable groups such as (meth)acryl groups and vinyl groups.

The aforementioned adhesive resin is preferably an acrylic resin, more preferably a (meth)acrylate copolymer containing a structural unit derived from (meth)acrylate.

When the above-mentioned adhesive layer contains a component that is polymerized by energy ray irradiation, such as an energy ray curable resin, it becomes energy ray curable, and the adhesiveness of the adhesive layer is lowered by irradiation of energy ray, and it is easy to Pick up the semiconductor wafer with protective film mentioned later. Such an adhesive layer can be formed using, for example, various adhesive compositions containing components polymerized by irradiation of energy rays.

<<Adhesive composition>>

As a preferable said adhesive composition, the adhesive composition containing the component which polymerizes by irradiating an energy ray is mentioned. As such an adhesive composition, for example, a composition containing an acrylic resin and an energy ray polymerizable compound (hereinafter, sometimes simply referred to as "adhesive composition (i)"), a composition containing a hydroxyl group and a side chain having The composition of the aforementioned acrylic resin and isocyanate-based crosslinking agent with a polymeric group (hereinafter sometimes referred to simply as "adhesive") Agent composition (ii)"), etc. As an acrylic resin which has the said hydroxyl group and has a polymeric group in a side chain, the acrylic resin etc. which have a hydroxyl group and have a polymeric group in a side chain via a urethane bond are mentioned, for example.

<Adhesive composition (i)>

The adhesive composition (i) contains the aforementioned acrylic resin and energy ray polymerizable compound as essential components.

Hereinafter, each component is demonstrated.

[acrylic resin]

As a preferable acrylic resin in the adhesive composition (i), for example, one obtained by polymerizing (meth)acrylate and, if necessary, a monomer other than (meth)acrylate is mentioned. The obtained (meth)acrylate copolymer.

Examples of the (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylic acid Pentyl ester, hexyl (meth)acrylate, heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ( n-nonyl methacrylate, isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate ((meth)acrylate ) lauryl acrylate), tridecyl (meth)acrylate, myristyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, ( Meth)acrylic cetyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, stearyl (meth)acrylate (stearyl (meth)acrylate), (meth)acrylate Base) isostearyl acrylate (isostearyl (meth)acrylate) and other alkyl (meth)acrylates in which the alkyl group constituting the alkyl ester is a chain structure with 1 to 18 carbon atoms; Cycloalkyl (meth)acrylates such as isobornyl methacrylate and dicyclopentanyl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; (meth) Cycloalkenyl (meth)acrylates such as dicyclopentenyl acrylate; Cycloalkenyloxyalkyl (meth)acrylates such as dicyclopentenyloxyethyl (meth)acrylate; (meth)acrylic acid Imine; glycidyl (meth)acrylate and other glycidyl-containing (meth)acrylates; hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid 2 -Hydroxypropyl, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc. Hydroxyl (meth)acrylate, etc.

As a monomer other than the said (meth)acrylate, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylol acrylamide etc. are mentioned, for example.

Various monomers, such as the said (meth)acrylate which comprises an acrylic resin, and monomers other than the said (meth)acrylate, may be only 1 type, and may be 2 or more types.

The acrylic resin contained in the adhesive composition (i) can be only 1 species, or more than two species.

The content of the acrylic resin in the adhesive composition (i) is preferably 40% by mass to 99% by mass, more preferably 50% by mass relative to the total amount of all components other than the solvent in the adhesive composition (i). % by mass to 91% by mass.

[Energy Ray Polymer Compound]

The aforementioned energy ray polymerizable compound is a compound that is polymerized and cured by irradiation with energy ray, and examples of the compound include compounds having energy ray polymerizable groups such as energy ray curable double bonds in the molecule.

Examples of the aforementioned energy ray polymerizable compound include low molecular weight compounds (monofunctional or polyfunctional monomers and oligomers) having an energy ray polymerizable group.

More specifically, examples of the energy ray polymerizable compound include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol Hexaacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate and other acrylates; dicyclopentadiene dimethoxy diacrylate and other acrylic acid containing cycloaliphatic skeleton esters; acrylate compounds such as polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy-modified acrylate, polyether acrylate, itaconic acid oligomer, etc.

The molecular weight of the aforementioned energy ray polymerizable compound is preferably from 100 to 30,000, more preferably from 300 to 10,000.

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

The content of the energy ray polymerizable compound in the adhesive composition (i) is preferably 1 to 125 parts by mass, more preferably 10 to 125 parts by mass relative to 100 parts by mass of the acrylic resin content.

[Photopolymerization Initiator]

The adhesive composition (i) may contain a photopolymerization initiator in addition to the aforementioned acrylic resin and energy ray polymerizable compound.

The aforementioned photopolymerization initiator may be a known photopolymerization initiator.

Specific examples of the photopolymerization initiator include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α′-di Methylacetophenone, 2-methyl-2-hydroxypropiophenone, 1-hydroxycyclohexyl phenylketone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl Base)-benzyl]phenyl}-2-methyl-propan-1-one and other α-ketol compounds; methoxyacetophenone, 2,2-dimethoxy-2-phenylphenethyl Acetophenones such as ketones, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholine propan-1-one Benzoin ether, benzoin isopropyl ether, anisoin methyl ether and other benzoin ether compounds; benzoyl dimethyl ketal and other ketal compounds; 2-naphthalenesulfonyl chloride and other aromatic sulfonyl chlorides Compound; 1-Benzone-1,1- Photoactive oxime compounds such as propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone Benzophenone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2, 4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone and other thioxanthone compounds; camphorquinone; halogenated ketones; acyl phosphine oxide; acyl Phosphonates/esters etc.

The photopolymerization initiator contained in the adhesive composition (i) may be only one type, or may be two or more types.

When using a photopolymerization initiator, the content of the photopolymerization initiator in the adhesive composition (i) is preferably 0.1 to 10 parts by mass relative to 100 parts by mass of the energy ray polymerizable compound. parts, more preferably 1 to 5 parts by mass. When the said content of a photoinitiator is more than the said lower limit, the effect by using a photoinitiator sufficient can be acquired. Moreover, when the said content of a photoinitiator is below the said upper limit, generation|occurrence|production of by-product components by an excess photoinitiator can be suppressed, and an adhesive layer can be hardened more favorably.

[Crosslinking agent]

The adhesive composition (i) may contain a crosslinking agent in addition to the aforementioned acrylic resin and energy ray polymerizable compound.

Examples of the aforementioned crosslinking agent include: organic polyvalent isocyanate Compounds, organic polyimine compounds, etc.

Examples of the organic polyvalent isocyanate compound include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, and trimers, isocyanurate bodies, and adducts of these compounds; An isocyanate-terminated urethane prepolymer obtained by reacting the aforementioned aromatic polyvalent isocyanate compound, aliphatic polyvalent isocyanate compound, or alicyclic polyvalent isocyanate compound with a polyol compound. The aforementioned adduct means that the aforementioned aromatic polyisocyanate compound, aliphatic polyisocyanate compound or alicyclic polyisocyanate compound is mixed with ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil, etc. Reactant of active hydrogen compounds.

As the aforementioned organic polyvalent isocyanate compound, more specifically, for example, 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylene diisocyanate; Isocyanate; Diphenylmethane-4,4'-diisocyanate; Diphenylmethane-2,4'-diisocyanate; 3-Methyldiphenylmethane diisocyanate; Hexamethylene diisocyanate; Isophorone Diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; all or part of the hydroxyl groups of polyols such as trimethylolpropane, addition of toluene diisocyanate and Any one or two compounds of hexamethylene diisocyanate; lysine diisocyanate, etc.

Examples of the aforementioned organic polyimine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-nitrogen Pyridylpropionate, tetramethylolmethane-tris-β-aziridinylpropionate, N,N'-toluene-2,4-bis(1-aziridinecarboxamide) triethylene base melamine etc.

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

The crosslinking agent contained in the adhesive composition (i) may be only one type, or may be two or more types.

When using a crosslinking agent, the content of the crosslinking agent in the adhesive composition (i) is preferably 0.01 to 20 parts by mass, more preferably 0.1 Parts by mass to 16 parts by mass.

[solvent]

The adhesive composition (i) preferably further contains a solvent in addition to the aforementioned acrylic resin and energy ray polymerizable compound.

The aforementioned solvent is not particularly limited.

Examples of preferable solvents include: hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropan-1-ol), and 1-butanol; acetic acid Esters such as ethyl esters; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds with amide bonds) such as dimethylformamide and N-methylpyrrolidone, etc.

The solvent contained in the adhesive composition (i) may be only one type, or may be two or more types.

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

[other ingredients]

In the adhesive composition (i), in addition to the above-mentioned acrylic resin and energy ray polymerizable compound, it may also contain substances other than the above-mentioned photopolymerization initiator, crosslinking agent, and solvent within the range that does not impair the efficacy of the present invention. other ingredients.

The aforementioned other components may be known components, and may be arbitrarily selected according to the purpose, and are not particularly limited. Examples of preferable other components include various additives such as dyes, pigments, anti-deterioration agents, antistatic agents, flame retardants, silicone compounds, and chain transfer agents.

The aforementioned other components contained in the adhesive composition (i) may be only one type, or may be two or more types.

<Adhesive composition (ii)>

The adhesive composition (ii) contains an acrylic resin and an isocyanate crosslinking agent as essential components, and the acrylic resin has a hydroxyl group and a polymerizable group in a side chain. Here, as said acrylic resin, the acrylic resin which has a hydroxyl group and has a polymeric group in a side chain via a urethane bond, etc. are mentioned, for example.

In the case of using the adhesive composition (ii), since the acrylic resin has a polymerizable group in the side chain, compared to the case of the adhesive composition (i), using an energy ray polymerizable compound, by When the polymerization reaction is carried out by irradiating energy rays, since the adhesiveness of the adhesive layer after the polymerization reaction (hardening) is lowered, the detachability from the adherend is improved, and the pick-up performance of the semiconductor wafer with a protective film is improved.

In addition, in this specification, description about the "acrylic resin" in the adhesive composition (ii) means "an acrylic resin having a polymerizable group in a side chain" unless otherwise specified.

[acrylic resin]

Examples of the aforementioned acrylic resin having a polymerizable group in the side chain include acrylic resins obtained by making a (meth)acrylate (in this specification, sometimes referred to as "Hydroxyl-free (meth)acrylates"), and hydroxyl-containing (meth)acrylates (in this specification, sometimes referred to as "hydroxyl-containing (meth)acrylates"), etc. The compound is copolymerized to obtain a hydroxyl-containing copolymer, and the hydroxyl group of the obtained hydroxyl-containing copolymer reacts with the isocyanate group of the compound having an isocyanate group and a polymerizable group to form a carbamate bond to obtain an acrylic resin.

Examples of the (meth)acrylates not containing a hydroxyl group include (meth)acrylic acid esters other than hydroxyl group-containing (meth)acrylates among the (meth)acrylates in the adhesive composition (i). ester.

Moreover, as the said hydroxyl-containing compound, the compound similar to the hydroxyl-containing (meth)acrylate in adhesive composition (i) is mentioned.

The (meth)acrylate which does not contain a hydroxyl group and the compound which contains a hydroxyl group which comprise the said acrylic resin may each be only 1 type, and may be 2 or more types.

Examples of the compound having an isocyanate group and a polymerizable group include isocyanate group-containing (meth)acrylates such as 2-methacryloxyethyl isocyanate.

The compound which has the said isocyanate group and a polymeric group which comprises the said acrylic resin may be only 1 type, and may be 2 or more types.

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

The content of the acrylic resin in the adhesive composition (ii) is preferably 80% by mass to 99% by mass, more preferably 90% by mass relative to the total amount of all components other than the solvent in the adhesive composition (ii). % by mass to 97% by mass.

[Isocyanate crosslinking agent]

As said isocyanate crosslinking agent, the compound similar to the said organic polyvalent isocyanate compound which is a crosslinking agent in adhesive composition (i) is mentioned, for example.

The isocyanate-based crosslinking agent contained in the adhesive composition (ii) may be only one type, or may be two or more types.

The number of moles of isocyanate groups contained in the isocyanate-based crosslinking agent in the adhesive composition (ii) relative to the number of moles of hydroxyl groups contained in the acrylic resin in the adhesive composition (ii) is preferably 0.2 times to 3 times. When the said molar number of an isocyanate group is more than the said lower limit, since the adhesiveness of the adhesive layer after hardening falls, the detachability from an adherend improves, and the pick-up property of the semiconductor wafer with a protective film improves. Moreover, when the said number of moles of an isocyanate group is below the said upper limit, generation|occurrence|production of by-products by reaction of isocyanate type crosslinking agents can be suppressed further.

The content of the isocyanate-based crosslinking agent in the adhesive composition (ii) is preferably adjusted appropriately so that the number of moles of isocyanate groups falls within the above range.

Furthermore, the content of the isocyanate-based crosslinking agent in the adhesive composition (ii) satisfies the condition of the number of moles of such isocyanate groups, and is preferably 0.01 parts by mass to 100 parts by mass of the content of the acrylic resin. 20 parts by mass, more preferably 0.1 to 15 parts by mass, more preferably 0.3 to 12 parts by mass.

[Photopolymerization Initiator]

The adhesive composition (ii) may contain a photopolymerization initiator in addition to the above-mentioned acrylic resin and isocyanate crosslinking agent.

As said photoinitiator, the photoinitiator similar to the case of the adhesive composition (i), for example is mentioned.

The photopolymerization initiator contained in the adhesive composition (ii) may be only one type, or may be two or more types.

When using a photopolymerization initiator, the content of the photopolymerization initiator in the adhesive composition (ii) is preferably 0.05 to 20 parts by mass relative to 100 parts by mass of the content of the acrylic resin. When the said content of a photoinitiator is more than the said lower limit, the effect by using a photoinitiator sufficient can be acquired. Moreover, when the said content of a photoinitiator is below the said upper limit, generation|occurrence|production of by-product components by an excess photoinitiator can be suppressed, and an adhesive layer can be hardened more favorably.

[solvent]

The adhesive composition (ii) preferably further contains a solvent in addition to the aforementioned acrylic resin and isocyanate crosslinking agent.

As said solvent, the thing similar to the case of the adhesive composition (i) is mentioned, for example.

The solvent contained in the adhesive composition (ii) may be only one kind, or may be two or more kinds.

When the adhesive composition (ii) contains a solvent, the content of the solvent in the adhesive composition (ii) is preferably from 40% by mass to 90% by mass, more preferably from 50% by mass to 80% by mass.

[other ingredients]

In the adhesive composition (ii), in addition to the above-mentioned acrylic resin and isocyanate-based crosslinking agent, other components that do not meet the above-mentioned photopolymerization initiator and solvent may also be contained within the range that does not impair the efficacy of the present invention.

As said other component, the thing similar to the case of the adhesive agent composition (i) is mentioned, for example.

The aforementioned other components contained in the adhesive composition (ii) may be only one type, or two or more types.

So far, the adhesive composition containing the component that polymerizes by irradiating energy rays has been described, but when forming the adhesive layer, an adhesive composition that does not contain a component that polymerizes by irradiating energy rays can also be used. That is, the adhesive layer may be non-energy ray curable without energy ray curability.

Such a preferable non-energy ray-curable adhesive composition includes, for example, a composition containing an acrylic resin and a crosslinking agent (hereinafter, may be simply referred to as "adhesive composition (iii)") and the like. The adhesive composition (iii) may contain optional components such as solvents and other components not compatible with solvents.

<Adhesive composition (iii)>

The aforementioned 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).

The content of the acrylic resin in the adhesive composition (iii) is preferably 40% by mass to 99% by mass, more preferably 50% by mass relative to the total amount of all components other than the solvent in the adhesive composition (iii). % by mass to 93% by mass.

The content of the crosslinking agent in the adhesive composition (iii) is preferably 3 to 30 parts by mass, more preferably 5 to 25 parts by mass relative to 100 parts by mass of the content of the acrylic resin.

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

<<Manufacturing method of adhesive composition>>

The aforementioned adhesive compositions such as the adhesive composition (i) to the adhesive composition (iii) can be obtained by using the aforementioned adhesive, components other than the aforementioned adhesive, etc. as necessary to constitute each The components of the adhesive composition are formulated.

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

There are no particular limitations on the method of mixing the ingredients during preparation, and it may be appropriately selected from the following known methods: rotating a stirring bar or a stirring blade, etc. Method of mixing; method of mixing using a mixer; method of mixing by applying ultrasonic waves, etc.

The temperature and time for adding and mixing the components are not particularly limited as long as the components are not degraded, and may be adjusted appropriately. The temperature is preferably 15°C to 30°C.

○Film for protective film formation

The film for forming a protective film may be any of thermosetting properties and energy ray curing properties. The film for protective film formation finally becomes a protective film with high impact resistance through curing. The protective film prevents, for example, cracks from occurring in the semiconductor wafer after the dicing step.

The film for forming a protective film can be formed using a composition for forming a thermosetting protective film or a composition for forming an energy ray curable protective film (hereinafter, these may be collectively referred to as "composition for forming a protective film") which will be described later. .

The film for protective film formation may be only one layer (single layer), or may be multiple layers of two or more layers. In the case of multiple layers, these multiple layers may be the same or different from each other. The combination of these multiple layers No particular limitation.

Although the thickness of the film for protective film formation is not specifically limited, Preferably it is 1 micrometer - 100 micrometers, More preferably, it is 5 micrometers - 75 micrometers, Most preferably, it is 5 micrometers - 50 micrometers. When the thickness of the film for protective film formation is more than the said lower limit, the adhesive force with respect to the semiconductor wafer which is an adherend, and a semiconductor wafer becomes larger. In addition, when the thickness of the film for protective film formation is the aforementioned upper limit Next, when picking up a semiconductor wafer, the protective film which is a cured product can be cut more easily by utilizing shearing force.

‧Film for thermosetting protective film formation

As a preferable film for thermosetting protective film formation, the film containing a polymer component (A) and a thermosetting component (B) is mentioned, for example. The polymer component (A) is regarded as a component formed by polymerizing a polymerizable compound. Moreover, a thermosetting component (B) is a component which can perform a hardening (polymerization) reaction using heat as a reaction trigger (trigger). Furthermore, in the present invention, the polycondensation reaction is also included in the polymerization reaction.

<<Thermosetting protective film forming composition>>

The film for forming a thermosetting protective film can be formed using a composition for forming a thermosetting protective film containing a constituent material of the film for forming a thermosetting protective film. For example, a thermosetting protective film-forming film can be formed on a target portion by applying a thermosetting protective film-forming composition to a surface to be formed of a thermosetting protective film-forming film and drying it if necessary. The content ratio of the components which do not vaporize at normal temperature in the composition for forming a thermosetting protective film is generally the same as the content ratio of the above-mentioned components in the film for forming a thermosetting protective film. Here, the term "normal temperature" is as described above.

What is necessary is to apply the composition for forming a thermosetting protective film by a known method, for example, the method of using the following various coating machines: air knife coating Machine, Blade Coater, Rod Coater, Gravure Coater, Roll Coater, Roller Knife Coater, Curtain Coater, Die Coater, Knife Coater, Screen Coater Coater, Meyer rod coater, contact coater, etc.

The drying conditions of the composition for forming a thermosetting protective film are not particularly limited, but when the composition for forming a thermosetting protective film contains a solvent described later, it is preferable to perform heat drying. The composition for forming a thermosetting protective film containing a solvent is, for example, preferably dried at 70° C. to 130° C. for 10 seconds to 5 minutes.

<Protective film forming composition (III-1)>

As a 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) can be mentioned (in this specification, there is sometimes referred to simply as "protective film-forming composition (III-1)") and the like.

[Polymer component (A)]

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

The polymer component (A) contained in the composition for forming a protective film (III-1) and the film for forming a thermosetting protective film may be only one kind, or may be two or more kinds, and in the case of two or more kinds , the combination and ratio of these can be chosen arbitrarily.

As the polymer component (A), for example, acrylic resin (with Resins with (meth)acryl groups), polyesters, urethane resins (resins with urethane bonds), acrylic urethane resins, polysiloxane resins (with silicon oxyalkylene bonds), rubber-based resins (resins with a rubber structure), phenoxy resins, thermosetting polyimides, etc., preferably acrylic resins.

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 from 10,000 to 2,000,000, more preferably from 100,000 to 1,500,000. When the weight average molecular weight of an acrylic resin is more than the said lower limit, the shape stability (time-dependent stability at the time of storage) of the film for thermosetting protective film formation improves. In addition, when the weight-average molecular weight of the acrylic resin is not more than the above-mentioned upper limit, the film for forming a thermosetting protective film becomes easy to follow the uneven surface of the adherend, and the adhesion between the adherend and the thermosetting protective film can be further suppressed. Voids and the like are generated between the films for formation.

The glass transition temperature (Tg) of the acrylic resin is preferably -60°C to 70°C, more preferably -30°C to 50°C. When Tg of an acrylic resin is more than the said lower limit, the adhesive force of a protective film and a support sheet can be suppressed, and the peelability of a support sheet improves. Moreover, when Tg of an acrylic resin is below the said upper limit, the adhesive force of the film for thermosetting protective film formation, a protective film, and an adherend improves.

As the acrylic resin, for example, one or more polymers of (meth)acrylates; selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene and N- Copolymers of two or more monomers such as methylolacrylamide, etc.

Examples of the (meth)acrylate constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate. ester, n-butyl (meth)acrylate, isobutyl (meth)acrylate, second-butyl (meth)acrylate, third-butyl (meth)acrylate, amyl (meth)acrylate, (meth)acrylate base) hexyl acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-(meth)acrylate Nonyl, isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate (lauryl (meth)acrylate) , Tridecyl (meth)acrylate, Myristyl (meth)acrylate (Myristyl (meth)acrylate), Pentadecyl (meth)acrylate, Decadecyl (meth)acrylate Hexaalkyl ester (palm (meth)acrylate), heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), etc. (meth)acrylic acid alkyl ester whose alkyl group is a chain structure with 1 to 18 carbon atoms; (meth)acrylic cycloalkane aralkyl (meth)acrylates such as benzyl (meth)acrylate; cycloalkenyl (meth)acrylates such as dicyclopentenyl (meth)acrylate; dicyclopentanyl (meth)acrylate Cycloalkenyloxyalkyl (meth)acrylates, etc.; (meth)acrylimide; (meth) Glycidyl acrylate and other glycidyl-containing (meth)acrylates; hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, (meth)acrylate Base) 3-hydroxypropyl acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and other hydroxyl-containing (meth)acrylic acid Esters; (meth)acrylates containing substituted amino groups such as N-methylaminoethyl (meth)acrylate, etc. Here, the "substituted amino group" means a group in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom.

The acrylic resin, for example, other than the aforementioned (meth)acrylates, may also be selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide. A resin obtained by copolymerizing one or more than two monomers.

The monomer which comprises an acrylic resin may be only 1 type, and may be 2 or more types, and when it is 2 or more types, the combination and ratio of these can be arbitrarily selected.

Acrylic resins may also have functional groups such as vinyl groups, (meth)acryl groups, amine groups, hydroxyl groups, carboxyl groups, and isocyanate groups that can bond with other compounds. The aforementioned functional groups in the acrylic resin may be bonded to other compounds via a crosslinking agent (F) described later, or may be directly bonded to other compounds without using a crosslinking agent (F). By bonding the acrylic resin to other compounds via the aforementioned functional groups, it is possible to obtain encapsulation using the composite sheet for forming a protective film. Tendency to improve reliability.

In the present invention, as the polymer component (A), thermoplastic resins other than acrylic resins (hereinafter, sometimes simply referred to as "thermoplastic resins") may be used in combination with acrylic resins. By using the above-mentioned thermoplastic resin, the release property of the protective film from the support sheet may be improved, or the film for forming a thermosetting protective film may easily follow the uneven surface of the adherend, thereby further suppressing the adhesion between the adherend and thermosetting. Pores and the like are generated between films for forming a protective film.

The weight average molecular weight of the aforementioned thermoplastic resin is preferably from 1,000 to 100,000, more preferably from 3,000 to 80,000.

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

As said thermoplastic resin, polyester, polyurethane, a phenoxy resin, polybutene, polybutadiene, polystyrene, etc. are mentioned, for example.

The aforementioned thermoplastic resin contained in the composition for forming a protective film (III-1) and the film for forming a thermosetting protective film may be only one kind, or may be two or more kinds. The combination and ratio can be chosen arbitrarily.

In the protective film forming composition (III-1), regardless of the polymer component (A) Regardless of the type, the ratio of the content of the polymer component (A) (that is, the content of the polymer component (A) in the film for forming a thermosetting protective film) to the total content of all components other than the solvent is preferable. 5% by mass to 50% by mass, more preferably 10% by mass to 40% by mass, most preferably 15% by mass to 35% by mass.

The polymer component (A) may also correspond to the thermosetting component (B). In the present invention, when the composition (III-1) for forming a protective film contains such a component corresponding to both the polymer component (A) and the thermosetting component (B), the composition for forming a protective film ( III-1) can be considered to contain a polymer component (A) and a thermosetting component (B).

[Thermosetting component (B)]

The thermosetting component (B) is a component for hardening the film for thermosetting protective film formation, and forming 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, or may be two or more types, and in the case of two or more types , the combination and ratio of these can be chosen arbitrarily.

Examples of the thermosetting component (B) include: epoxy-based thermosetting resins, thermosetting polyimides, polyurethanes, unsaturated polyesters, silicone resins, etc., preferably Epoxy based thermosetting resin.

(Epoxy Thermosetting Resin)

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

The epoxy-based thermosetting resin contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one type, or may be two or more types, and in the case of two or more types , the combination and ratio of these can be chosen arbitrarily.

‧Epoxy resin (B1)

Examples of the epoxy resin (B1) include known epoxy resins, such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and hydrogenated products thereof, o-cresol novolac epoxy resins, and polyfunctional epoxy resins. Resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin, etc. compound.

An epoxy resin having an unsaturated hydrocarbon group can also be used as the epoxy resin (B1). Epoxy resins with unsaturated hydrocarbon groups are more compatible with acrylic resins than epoxy resins without unsaturated hydrocarbon groups. Therefore, by using the epoxy resin which has an unsaturated hydrocarbon group, the reliability of the package obtained using the composite sheet for protective film formation improves.

As an epoxy resin having an unsaturated hydrocarbon group, for example, a polyfunctional epoxy resin in which a part of the epoxy group is replaced with an unsaturated hydrocarbon group based compounds. Such a compound is obtained, for example, by adding (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 bonded to 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 of the unsaturated hydrocarbon group include ethylene (vinyl), 2-propenyl (allyl), (meth)acryl, (Meth)acrylamide group etc., Preferably it is acryl group.

In addition, in this specification, a "derivative" means a compound in which one or more hydrogen atoms of the original compound are substituted with a group (substituent) other than a hydrogen atom.

The number average molecular weight of the epoxy resin (B1) is not particularly limited, but is preferably 300 to 30,000 in terms of the curability of the film for forming a thermosetting protective film, and the strength and heat resistance of the cured protective film. , more preferably 300 to 10000, especially preferably 300 to 3000.

The epoxy equivalent of the epoxy resin (B1) is preferably from 100 g/eq to 1100 g/eq, more preferably from 150 g/eq to 1000 g/eq.

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

‧Thermal curing 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 functional groups which can react with an epoxy group in 1 molecule is mentioned, for example. Examples of the aforementioned functional groups include: phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, groups formed by anhydrided acid groups, etc., preferably phenolic hydroxyl groups, amino groups, or groups formed by anhydrided acid groups. The base is 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, novolak-type phenolic resins, dicyclopentadiene-based phenolic resins, and aralkylphenolic resins. resin etc.

Among the thermosetting agents (B2), dicyandiamine (hereinafter, may be abbreviated as "DICY" in some cases) etc. are mentioned as an amine-type hardening agent which has an amino group, for example.

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

Examples of the thermosetting agent (B2) having an unsaturated hydrocarbon group include: a compound in which a part of the hydroxyl groups of a phenol resin is substituted by a group having an unsaturated hydrocarbon group; a group having an unsaturated hydrocarbon group directly bonded to the aromatic ring of the phenol resin; Compounds etc.

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

When using a phenolic hardener as a thermal hardener (B2), it is The thermosetting agent (B2) is preferably a phenolic curing agent having a high softening point or glass transition temperature from the viewpoint of improving the peelability of the cover sheet from the support sheet.

The thermosetting agent (B2) is preferably solid at normal temperature and does not show hardening activity to the epoxy resin (B1), on the other hand, it is dissolved by heating and shows hardening activity to the epoxy resin (B1). Thermosetting agent (hereinafter, sometimes simply referred to as "thermoactive latent epoxy resin curing agent").

The aforementioned thermally active latent epoxy resin hardener is stably dispersed in the epoxy resin (B1) in the film for forming a thermosetting protective film at normal temperature, but is compatible with the epoxy resin (B1) by heating, and Reacts with epoxy resins (B1). The storage stability of the composite sheet for protective film formation is remarkably improved by using the said thermally active latent epoxy resin hardener. For example, the transfer of the curing agent from the film for forming a protective film to the adjacent support sheet can be suppressed, and a decrease in the thermosetting properties of the film for forming a thermosetting protective film can be effectively suppressed. And since the thermosetting degree of the film for thermosetting protective film formation becomes higher by heating, the pick-up property of the semiconductor wafer with a protective film mentioned later improves further.

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

In the thermosetting agent (B2), the number average molecular weight of resin components such as polyfunctional phenol resins, novolak-type phenol resins, dicyclopentadiene-based phenol resins, and aralkylphenol resins is preferably from 300 to 30,000, more preferably 400 to 10000, preferably 500 to 3000.

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

The thermosetting agent (B2) may be used individually by 1 type, and may use 2 or more types together, and when using 2 or more types together, the combination and ratio of these can be chosen arbitrarily.

In the composition (III-1) for forming a protective film and the film for forming a thermosetting protective film, the content of the thermosetting agent (B2) is preferably 0.1 parts by mass relative to 100 parts by mass of the content of the epoxy resin (B1). to 500 parts by mass, more preferably 1 to 200 parts by mass. When the said content of a thermosetting agent (B2) is more than the said lower limit, it becomes easy to harden|cure the film for thermosetting protective film formation. Moreover, when the said content of a thermosetting agent (B2) is below the said upper limit, the moisture absorption rate of the film for thermosetting protective film formation falls, and the reliability of the package obtained using the composite sheet for protective film formation improves further. .

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) ) is preferably 1 to 100 parts by mass, more preferably 1.5 to 85 parts by mass, and especially preferably 2 to 70 parts by mass relative to 100 parts by mass of the polymer component (A). When the said content of a thermosetting component (B) is such a range, the adhesive force of a protective film and a support sheet is suppressed, and the peelability of a support sheet improves.

[Hardening Accelerator (C)]

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

Examples of preferred hardening accelerators (C) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5- Imidazoles such as hydroxymethylimidazole (imidazoles in which more than one hydrogen atom is replaced by a group other than hydrogen atoms); organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (more than one hydrogen atom Phosphine in which the hydrogen atom is replaced by an organic group); tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate and other tetraphenylboron salts, etc.

The curing accelerator (C) contained in the composition for forming a protective film (III-1) and the film for forming a thermosetting protective film may be only one kind, or may be two or more kinds, and in the case of two or more kinds , the combination and ratio of these can be chosen arbitrarily.

When the hardening accelerator (C) is used, in the protective film forming composition (III-1) and the thermosetting protective film forming film, the content of the hardening accelerator (C) relative to the thermosetting component (B ) content of 100 parts by mass, preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass. When the said content of a hardening accelerator (C) is more than the said lower limit, the remarkable effect by using a hardening accelerator (C) can be acquired. Other In addition, when the content of the hardening accelerator (C) is not more than the above-mentioned upper limit, for example, the high-polarity hardening accelerator (C) is suppressed from forming a thermosetting protective film in the film for forming a thermosetting protective film. The effect of segregation by transfer of the adherend to the interface side becomes higher, and the reliability of the package obtained by using the composite sheet for forming a protective film is further improved.

[Filler (D)]

The composition (III-1) for protective film formation and the film for thermosetting protective film formation may contain a filler (D). When the film for forming a thermosetting protective film contains the filler (D), the thermal expansion coefficient of the protective film obtained by curing the film for forming a thermosetting protective film can be easily adjusted. And by making this coefficient of thermal expansion optimal for the object to which a protective film is formed, the reliability of the package obtained using the composite sheet for protective film formation improves further. Moreover, when the film for thermosetting protective film formation contains a filler (D), the moisture absorption rate of a protective film can also be reduced, and heat dissipation can be improved.

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

As preferred inorganic fillers, for example, powders of silicon dioxide, alumina, talc, calcium carbonate, titanium dioxide, iron oxide, silicon carbide, boron nitride, etc. can be listed; these inorganic fillers are spheroidized beads; surface modified products of such inorganic fillers; single crystal fibers of such inorganic fillers; glass fibers, etc.

Among them, the inorganic filler is preferably silica or alumina.

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

In the case of using the filler (D), the content of the filler (D) in the protective film forming composition (III-1) (that is, the filler (D) in the thermosetting protective film forming film content) relative to the total content of all components other than the solvent is preferably 5% by mass to 80% by mass, more preferably 7% by mass to 60% by mass. When the content of the filler (D) is within such a range, it becomes easier to adjust the above-mentioned coefficient of thermal expansion.

[Coupling agent (E)]

The composition (III-1) for protective film formation and the film for thermosetting protective film formation may contain coupling agent (E). By using the compound which has the functional group which can react with an inorganic compound or an organic compound as a coupling agent (E), the adhesiveness and adhesiveness of the film for thermosetting protective film formation to an adherend can be improved. Moreover, water resistance improves the protective film obtained by hardening the film for thermosetting protective film formation by using a coupling agent (E) without impairing heat resistance.

The coupling agent (E) is preferably a compound having a functional group capable of reacting with a functional group possessed by the polymer component (A) or the thermosetting component (B), more preferably a silane coupling agent.

As a preferred aforementioned silane coupling agent, for example, 3-glycidyl Oleoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxymethyldiethoxysilane Oxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3 -(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyl Trimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane , bis(3-triethoxysilylpropyl) tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole Silane etc.

The coupling agent (E) contained in the composition for forming a protective film (III-1) and the film for forming a thermosetting protective film may be only one kind, or may be two or more kinds, and in the case of two or more kinds, The combination and ratio of these can be selected arbitrarily.

In the case of using the coupling agent (E), in the protective film forming composition (III-1) and the thermosetting protective film forming film, the content of the coupling agent (E) relative to the polymer component (A) and thermal The total content of the hardening component (B) is 100 parts by mass, preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, especially preferably 0.1 to 5 parts by mass. When the aforementioned content of the coupling agent (E) is above the aforementioned lower limit value, the following effect brought by the use of the coupling agent (E) can be obtained more significantly: the dispersibility of the filler (D) in the resin is improved, or Between film for thermosetting protective film formation and adherend Adherence improvement, etc. Moreover, when the said content of a coupling agent (E) is below the said upper limit, generation|occurrence|production of outgassing can be further suppressed.

[Crosslinking agent (F)]

In the case of using the above-mentioned acrylic resin having a functional group that can bond with other compounds, such as vinyl group, (meth)acryl group, amine group, hydroxyl group, carboxyl group, isocyanate group, etc., as the polymer component (A) In this case, the composition (III-1) for forming a protective film and the film for forming a thermosetting protective film may also contain a crosslinking agent (F). The crosslinking agent (F) is a component for crosslinking the above-mentioned functional group in the polymer component (A) with other compounds, and by crosslinking in this way, the film for forming a thermosetting protective film can be adjusted initial adhesion and cohesion.

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 agent (crosslinking agent with aziridine group), etc.

Examples of the above-mentioned organic polyvalent isocyanate compounds include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, and alicyclic polyvalent isocyanate compounds (hereinafter, these compounds may be collectively referred to as "aromatic polyvalent isocyanate compounds, etc.") ; trimers, isocyanurate bodies and adducts of the aforementioned aromatic polyisocyanate compounds, etc.; making the aforementioned aromatic polyisocyanate compounds, etc. The terminal isocyanate urethane prepolymer obtained by reaction, etc. The aforementioned "adduct" means that the aforementioned aromatic polyisocyanate compound, aliphatic polyisocyanate compound or alicyclic polyisocyanate compound is mixed with ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil, etc. Reactant of low molecular weight active hydrogen compounds. As an example of the said adduct, the xylylene diisocyanate adduct of trimethylolpropane mentioned later etc. are mentioned. In addition, the "terminated isocyanate urethane prepolymer" is as described above.

As the aforementioned organic polyvalent isocyanate compound, more specifically, for example, 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylene diisocyanate; Isocyanate; Diphenylmethane-4,4'-diisocyanate; Diphenylmethane-2,4'-diisocyanate; 3-Methyldiphenylmethane diisocyanate; Hexamethylene diisocyanate; Isophorone Diisocyanate; Dicyclohexylmethane-4,4'-diisocyanate; Dicyclohexylmethane-2,4'-diisocyanate; Toluene diisocyanate, Compounds of any one or two or more of hexamethylene diisocyanate and xylylene diisocyanate; lysine diisocyanate, etc.

Examples of the aforementioned organic polyimine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-nitrogen Pyridylpropionate, tetramethylolmethane-tris-β-aziridinylpropionate, N,N'-toluene-2,4-bis(1-aziridinecarboxamide) triethylene base melamine Wait.

When using an organic polyvalent isocyanate compound as a crosslinking agent (F), it is preferable to use a hydroxyl group-containing polymer as the polymer component (A). When the crosslinking agent (F) has an isocyanate group and the polymer component (A) has a hydroxyl group, the crosslinking structure can be easily introduced into the In the film for thermosetting protective film formation.

The crosslinking agent (F) contained in the composition for forming a protective film (III-1) and the film for forming a thermosetting protective film may be only one kind, or may be two or more kinds, and in the case of two or more kinds , the combination and ratio of these can be chosen arbitrarily.

When using a crosslinking agent (F), in the protective film forming composition (III-1), the content of the crosslinking agent (F) is preferably 100 parts by mass relative to the content of the polymer component (A). 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, most preferably 0.5 to 5 parts by mass. When the said content of a crosslinking agent (F) is more than the said lower limit, the more remarkable effect by using a crosslinking agent (F) can be acquired. Moreover, when the said content of a crosslinking agent (F) is below the said upper limit, the adhesive force of the film for thermosetting protective film formation and a support sheet, or the film for thermosetting protective film formation and a semiconductor wafer or The adhesive force of the semiconductor wafer is excessively reduced.

In the present invention, even without using a crosslinking agent (F), the effects of the present invention can be sufficiently obtained.

[energy ray curable resin (G)]

The composition (III-1) for protective film formation may contain energy ray curable resin (G). The film for thermosetting protective film formation can change a characteristic by irradiating an energy ray by containing an energy ray curable resin (G).

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

Examples of the energy ray-curable compound include compounds having at least one polymerizable double bond in the molecule, preferably acrylate compounds having a (meth)acryl group.

Examples of the acrylate-based compounds include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and pentaerythritol tetra(meth)acrylate. base) acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate (Meth)acrylates containing chain aliphatic skeletons such as (meth)acrylates; (meth)acrylates containing cycloaliphatic skeletons such as dicyclopentanyl di(meth)acrylate; polyethylene glycol Polyalkylene glycol (meth)acrylates such as di(meth)acrylates; Oligoester (meth)acrylates; Urethane (meth)acrylate oligomers; Epoxy modified (meth)acrylates base) acrylates; polyether (meth)acrylates other than the aforementioned polyalkylene glycol (meth)acrylates; itaconic acid oligomers, etc.

The weight average molecular weight of the aforementioned energy ray curable compound is preferably from 100 to 30,000, more preferably from 300 to 10,000.

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

The energy ray-curable resin (G) contained in the composition for forming a protective film (III-1) may be only one type, or may be two or more types. In the case of two or more types, the combination and ratio of these Optional.

In the case of using the energy ray curable resin (G), the content of the energy ray curable resin (G) in the protective film forming composition (III-1) is preferably from 1% by mass to 95% by mass, more preferably It is 2% by mass to 90% by mass, more preferably 3% by mass to 85% by mass.

[Photopolymerization initiator (H)]

When the protective film forming composition (III-1) contains the energy ray curable resin (G), a photopolymerization initiator may be included in order to efficiently polymerize the energy ray curable resin (G) (H).

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

The photopolymerization initiator (H) contained in the protective film forming composition (III-1) may be only one type, or may be two or more types, and in the case of two or more types, the combination and ratio of these Optional.

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

[Color (I)]

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

As a coloring agent (I), well-known coloring agents, such as an inorganic pigment, an organic pigment, and an organic dye, are mentioned, for example.

Examples of the aforementioned organic pigments and organic dyes include ammonium-based dyes, cyanine-based dyes, merocyanine-based dyes, croconium-based dyes, squalilium-based dyes, azulenium-based Pigments, polymethine pigments, naphthoquinone pigments, pyrylium pigments, phthalocyanine pigments, naphthalocyanine pigments, naphtholactamide pigments, azo pigments, condensed azo pigments, indigo pigments , Perinone-based pigments, perylene-based pigments, dioxane-based pigments, quinacridone-based pigments, isoindolinone-based colors Pigments, quinophthalone pigments, pyrrole pigments, thioindigo pigments, metal complex pigments (metal complex salt dyes), dithiol metal complex pigments, indoxyl pigments, Triallylmethane dyes, anthraquinone dyes, naphthol dyes, methine azo dyes, benzimidazolone dyes, pyranthrone dyes, threne dyes, and the like.

Examples of the inorganic pigments include carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO (Indium Tin Oxide; Indium Tin Oxide) pigments, ATO (Antimony Tin Oxide; Antimony Tin Oxide) pigments, etc.

The colorant (I) contained in the composition (III-1) for forming a protective film and the film for forming a thermosetting protective film may be only one kind, or may be two or more kinds, and in the case of two or more kinds, The combination and ratio of these can be selected arbitrarily.

When using a coloring agent (I), what is necessary is just to adjust content of the coloring agent (I) in the film for thermosetting protective film formation suitably according to the objective. For example, sometimes printing is performed on a protective film by laser irradiation, and by adjusting the content of the colorant (I) in the film for forming a thermosetting protective film and adjusting the light transmittance of the protective film, the visibility of printed characters can be adjusted. Moreover, by adjusting content of the coloring agent (I) in the film for thermosetting protective film formation, the design property of a protective film can be improved, and the grinding trace of the back surface of a semiconductor wafer can also be made difficult to see. Considering this aspect, in the protective film forming composition (III-1), the content of the colorant (I) (also That is, the ratio of the content of the coloring agent (I) in the film for forming a thermosetting protective film) to the total content of all components other than the solvent is preferably 0.1% by mass to 10% by mass, more preferably 0.1% by mass to 10% by mass. 7.5% by mass, preferably 0.1% by mass to 5% by mass, for example, any one of 0.1% by mass to 3% by mass and 0.1% by mass to 1% by mass. When the said content of a coloring agent (I) is more than the said lower limit, the more remarkable effect by using a coloring agent (I) can be acquired. Moreover, when the said content of a coloring agent (I) is below the said upper limit, it can suppress that the translucency of the film for thermosetting protective film formation falls too much.

[General additive (J)]

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

The general-purpose additive (J) can be a known additive, which can be arbitrarily selected according to the purpose, and is not particularly limited. Preferred general-purpose additives (J) include, for example, plasticizers, antistatic agents, antioxidants, and getters. (gettering agent) and so on.

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, or may be two or more types, and in the case of two or more types, The combination and ratio of these can be selected arbitrarily.

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 according to the purpose.

[solvent]

It is preferable that the composition (III-1) for protective film formation further contains a solvent. The composition (III-1) for forming a protective film containing a solvent has good handleability.

The aforementioned solvent is not particularly limited.

Examples of preferable solvents include: hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropan-1-ol), and 1-butanol; acetic acid Esters such as ethyl ester and butyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds with amide bonds) such as dimethylformamide and N-methylpyrrolidone, etc.

The solvent contained in the composition (III-1) for protective film formation may be only 1 type, and may be 2 or more types, and in the case of 2 or more types, the combination and ratio of these can be chosen arbitrarily.

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

<<Manufacturing method of thermosetting protective film forming composition>>

A composition for thermosetting protective film formation, such as composition for protective film formation (III-1), is obtained by preparing each component which comprises this composition.

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

In the case of using a solvent, it can be used by using The solvent is mixed with any of the formulated components other than the solvent and diluted in advance; it can also be used by mixing the solvent with the formulated components without pre-diluting any of the formulated components other than the solvent.

There are no particular limitations on the method of mixing the ingredients during preparation, and it is sufficient to select from the following known methods: a method of mixing by rotating a stirring bar or a stirring blade; a method of mixing by using a mixer; and mixing by applying ultrasonic waves. method etc.

The temperature and time for adding and mixing the components are not particularly limited as long as the components are not degraded, and may be appropriately adjusted. The temperature is preferably 15°C to 30°C.

‧Film for forming energy ray curable protective film

The film for forming an energy ray curable protective film contains an energy ray curable component (a).

The energy ray curable component (a) is preferably uncured, preferably adhesive, more preferably uncured and adhesive. Here, the "energy ray" and "energy ray curability" are as described above.

<<Composition for forming energy ray curable protective film>>

The film for forming an energy ray curable protective film can be formed using a composition for forming an energy ray curable protective film containing a constituent material of the film. For example, the composition for forming an energy ray curable protective film is applied to the surface to be formed of the film for forming an energy ray curable protective film, and dried as necessary to form an energy ray curable protective film on the target site. membrane. energy line The content ratio of the components that do not vaporize at normal temperature in the composition for forming a curable protective film is generally the same as the content ratio of the above-mentioned components in the film for forming an energy ray curable protective film. Here, the term "normal temperature" is as described above.

It is sufficient to apply the composition for forming an energy ray curable protective film by a known method, for example, the method using the following various coaters: air knife coater, knife coater, rod coater, gravure coater, etc. Cloth machine, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, wire wound rod coater, contact coater Cloth machines, etc.

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

<Protective film forming composition (IV-1)>

Examples of the composition for forming an energy ray curable protective film include, for example, the composition for forming an energy ray curable protective film (IV-1) containing the aforementioned energy ray curable component (a) (in this specification, sometimes referred to simply as "Composition for Forming a Protective Film (IV-1)") and the like.

[energy ray hardening ingredient (a)]

The energy ray curable component (a) is a component that is converted by irradiation of energy ray, and is used to impart film formability, flexibility, etc. to the film for forming an energy ray curable protective film.

Examples of the energy ray-curable component (a) include polymer (a1) having an energy ray-curable group and having a weight average molecular weight of 80,000 to 2,000,000, and compounds having an energy ray-curable group and having a molecular weight of 100 to 80,000 (a2). The aforementioned polymer (a1) may be at least partly crosslinked by 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)

As the polymer (a1) having an energy ray curable group and having a weight-average molecular weight of 80,000 to 2,000,000, for example, an acrylic resin (a1-1) made of an acrylic polymer ( a11) is formed by addition reaction with an energy ray-curable compound (a12), the acrylic polymer (a11) has a functional group capable of reacting with groups of other compounds, and the energy ray-curable compound (a12) has An energy ray curable group such as a group reactive with the aforementioned functional group and an energy ray curable double bond.

Examples of the functional groups that can react with groups of other compounds include hydroxyl, carboxyl, amino, and substituted amino groups (one or two hydrogen atoms of the amino group are replaced by groups other than hydrogen atoms) group), epoxy group, etc. However, the aforementioned functional group is preferably a group other than a carboxyl group from the viewpoint of preventing corrosion of a semiconductor wafer or a circuit of a semiconductor wafer or the like.

Among them, the aforementioned functional group is preferably a hydroxyl group.

‧Acrylic polymer with functional groups (a11)

The aforementioned acrylic polymer (a11) having a functional group includes, for example, a polymer obtained by copolymerizing the aforementioned acrylic monomer having a functional group and the aforementioned acrylic monomer having no functional group. In addition to these monomers, a polymer obtained by further copolymerizing monomers other than acrylic monomers (non-acrylic monomers).

In addition, the aforementioned acrylic polymer (a11) may be a random copolymer or a block copolymer.

Examples of the aforementioned acrylic monomers having functional groups include: hydroxyl-containing monomers, carboxyl-containing monomers, amine-containing monomers, substituted amino-containing monomers, epoxy-containing monomers, etc. .

Examples of the hydroxyl group-containing monomer include: hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxy (meth)acrylate Hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and other hydroxyalkyl (meth)acrylates; vinyl alcohol, Non-(meth)acrylic unsaturated alcohols (unsaturated alcohols not having a (meth)acryl skeleton) such as allyl alcohol, and the like.

Examples of the aforementioned carboxyl group-containing monomers include (meth)acrylic Ethylenically unsaturated monocarboxylic acids (monocarboxylic acids with ethylenically unsaturated bonds) such as acid and crotonic acid; ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid and citraconic acid ( dicarboxylic acids having ethylenically unsaturated bonds); anhydrides of the aforementioned ethylenically unsaturated dicarboxylic acids; carboxyalkyl (meth)acrylates such as 2-carboxyethyl methacrylate, and the like.

The aforementioned acrylic monomers having functional groups are preferably hydroxyl-containing monomers and carboxyl-containing monomers, more preferably hydroxyl-containing monomers.

The aforementioned acrylic monomers having functional groups constituting the aforementioned acrylic polymer (a11) may be only one type, or may be two or more types, and in the case of two or more types, the combination and ratio of these can be selected arbitrarily .

Examples of the acrylic monomer having no functional group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, Butyl (meth)acrylate, isobutyl (meth)acrylate, second-butyl (meth)acrylate, third-butyl (meth)acrylate, amyl (meth)acrylate, (meth) Hexyl 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, Undecyl (meth)acrylate, Dodecyl (meth)acrylate (Lauryl (meth)acrylate), ( Tridecyl Methacrylate, Myristyl (Meth)acrylate (Myristyl (Meth)acrylate), Pentadecyl (Meth)acrylate, Acrylic (Meth) Hexadecyl (meth)acrylate palmityl, heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate) and other constituent alkanes The alkyl group of the base ester is an alkyl (meth)acrylate with a chain structure of 1 to 18 carbon atoms.

In addition, examples of the above-mentioned acrylic monomer having no functional group include methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, etc. (meth)acrylic acid esters containing alkoxyalkyl groups such as ethoxyethyl (meth)acrylate; (meth)acrylate; non-cross-linked (meth)acrylamide and its derivatives; (meth)acrylate N,N-dimethylaminoethyl ester, (meth)acrylate N,N- Non-crosslinked (meth)acrylates with tertiary amino groups such as dimethylaminopropyl ester, etc.

The aforementioned acrylic monomers having no functional groups constituting the aforementioned acrylic polymer (a11) may be only one type, or may be two or more types, and in the case of two or more types, the combinations and ratios may be arbitrary choose.

Examples of the non-acrylic monomers include olefins such as ethylene and norbornene; vinyl acetate; and styrene.

The said non-acrylic monomer which comprises the said acrylic polymer (a11) may be only 1 type, and may be 2 or more types, and when it is 2 or more types, the combination and ratio of these can be chosen arbitrarily.

In the aforementioned acrylic polymer (a11), the ratio (content) of the amount of structural units derived from the aforementioned acrylic monomer having a functional group to the total amount of structural units constituting the aforementioned acrylic polymer (a11) is preferable 0.1% by mass to 50% by mass, more preferably 1% by mass to 40% by mass, most preferably 3% by mass to 30% by mass. With the aforementioned ratio in such a range, the energy ray-curable group in the aforementioned acrylic resin (a1-1) obtained by copolymerization of the aforementioned acrylic polymer (a11) and the aforementioned energy ray-curable compound (a12) can be The content of is easily adjusted to a range where the degree of hardening of the protective film is better.

The above-mentioned acrylic polymer (a11) constituting the above-mentioned acrylic resin (a1-1) may be only one type, or two or more types. In the case of two or more types, the combination and ratio of these can be selected arbitrarily .

In the composition for forming a protective film (IV-1), the content of the acrylic resin (a1-1) is preferably from 1% by mass to 40% by mass, more preferably from 2% by mass to 30% by mass, most preferably 3% by mass % to 20% by mass.

‧Energy ray hardening compound (a12)

The energy ray-curable compound (a12) preferably has one or more kinds selected from the group consisting of an isocyanate group, an epoxy group, and a carboxyl group as a compound that can be combined with the acrylic polymer (a11) The functional group-reactive group preferably has an isocyanate group as the aforementioned group. In the aforementioned energy ray-curable compound (a12), for example, one having an isocyanate group as the aforementioned group In some cases, the isocyanate group easily reacts with the hydroxyl group of the aforementioned acrylic polymer (a11) having a hydroxyl group as a functional group.

The aforementioned energy ray curable compound (a12) preferably has 1 to 5 aforementioned energy ray curable groups in 1 molecule, more preferably has 1 to 2 groups.

Examples of the energy ray-curing compound (a12) include 2-methacryloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryl isocyanate, allyl isocyanate, 1,1-(bisacryloxymethyl)ethyl isocyanate; by reaction of diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth)acrylate Acryl monoisocyanate compound obtained; acryl monoisocyanate compound obtained by reaction of diisocyanate compound or polyisocyanate compound, polyol compound and hydroxyethyl (meth)acrylate, etc.

Among them, the aforementioned energy ray-curable compound (a12) is preferably 2-methacryloxyethyl isocyanate.

The aforementioned energy ray-curable compound (a12) constituting the aforementioned acrylic resin (a1-1) may be only one type, or may be two or more types. choose.

Among the aforementioned acrylic resins (a1-1), those derived from the aforementioned energy ray curability The ratio of the content of the energy ray-curable group in the compound (a12) to the content of the functional group derived from the acrylic polymer (a11) is preferably 20 mol% to 120 mol%, more preferably 35 mol%. mol% to 100 mol%, especially preferably 50 mol% to 100 mol%. When the ratio of the said content is such a range, the adhesive force of the protective film after hardening becomes larger further. Furthermore, in the case where the aforementioned energy ray-curable compound (a12) is a functional compound (having one of the aforementioned groups in 1 molecule), the upper limit of the ratio of the aforementioned content is 100 mol%. When the line-curing compound (a12) is a polyfunctional (having two or more of the above-mentioned groups in one molecule) compound, the upper limit of the ratio of the above-mentioned content may exceed 100 mol%.

The weight average molecular weight (Mw) of the aforementioned polymer (a1) is preferably from 100,000 to 2,000,000, more preferably from 300,000 to 1,500,000.

Here, the "weight average molecular weight" is as described above.

When at least a part of the aforementioned polymer (a1) is cross-linked by a cross-linking agent, the aforementioned polymer (a1) may contain any monomer constituting the aforementioned acrylic polymer (a11) that does not meet the above description and A monomer having a group reactive with a crosslinking agent is polymerized to perform crosslinking in the group reactive with the crosslinking agent, or a group derived from the energy ray-curable compound (a12) that reacts with the functional group can be crosslinked. in cross-linking.

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

(Compound (a2) having an energy ray curable group and having a molecular weight of 100 to 80000)

Examples of the aforementioned energy ray curable group in the compound (a2) having an energy ray curable group and a molecular weight of 100 to 80000 include a group containing an energy ray curable double bond, and preferable examples of the group include (a base) acryl, vinyl, etc.

As long as the above-mentioned compound (a2) satisfies the above conditions, it is not particularly limited, and examples thereof include: low-molecular-weight compounds having energy ray-curable groups, epoxy resins having energy ray-curable groups, and phenol resins having energy ray-curable groups Wait.

Among the aforementioned compounds (a2), examples of low-molecular-weight compounds having energy-ray-curable groups include polyfunctional monomers or oligomers, and acrylate compounds having (meth)acryl groups are preferred.

Examples of the aforementioned acrylate-based compounds include: 2-hydroxy-3-(meth)acryloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxy bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A bis(methyl) ) acrylate, 2,2-bis[4-((meth)acryloxydiethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloxy Ethoxy) benzene base] fennel, 2,2-bis[4-((meth)acryloxypolypropoxy)phenyl]propane, tricyclodecane dimethanol di(meth)acrylate, 1,10-decanedi Alcohol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tri Propylene Glycol Di(meth)acrylate, Polypropylene Glycol Di(meth)acrylate, Polybutylene Glycol Di(meth)acrylate, Ethylene Glycol Di(meth)acrylate, Diethylene Glycol Di(meth)acrylate ) acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloxyethoxy)phenyl]propane, neopentyl glycol di(methyl) ) acrylates, ethoxylated polypropylene glycol di(meth)acrylates, 2-hydroxy-1,3-di(meth)acryloxypropane and other bifunctional (meth)acrylates; isocyanuric acid Tris(2-(meth)acryloxyethyl)ester, ε-caprolactone modified tris-(2-(meth)acryloxyethyl)isocyanurate, ethoxylated Glyceryl tri(meth)acrylate, Pentaerythritol tri(meth)acrylate, Trimethylolpropane tri(meth)acrylate, Di-trimethylolpropane tetra(meth)acrylate, Ethoxylated Multifunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, dipentaerythritol hexa(meth)acrylate; ) polyfunctional (meth)acrylate oligomers such as urethane acrylate oligomers, etc.

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

The weight average molecular weight of the aforementioned compound (a2) is preferably from 100 to 30,000, more preferably from 300 to 10,000.

The aforementioned compound (a2) contained in the composition for forming a protective film (IV-1) and the film for forming an energy ray curable protective film may be only one kind, or may be two or more kinds, and in the case of two or more kinds , the combination and ratio of these can be chosen arbitrarily.

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

When the composition (IV-1) for forming a protective film and the film for forming an energy ray curable protective film contain the aforementioned compound (a2) as the aforementioned energy ray curable component (a), it is preferable to further contain Energy ray curable polymer (b).

The aforementioned polymer (b) may be at least partially cross-linked by a cross-linking agent, or may not be cross-linked.

Examples of the polymer (b) not having an energy ray curable group include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber-based resins, and acrylic urethane resins. Wait.

Among them, the aforementioned polymer (b) is preferably an acrylic polymer (hereinafter, may be simply referred to as "acrylic polymer (b-1)").

The acrylic polymer (b-1) can be a known polymer, for example, it can be 1 A homopolymer of acrylic monomers, or a copolymer of two or more acrylic monomers, or one or more acrylic monomers and one or more acrylic monomers Copolymers of monomers (non-acrylic monomers).

Examples of the acrylic monomers constituting the acrylic polymer (b-1) include alkyl (meth)acrylates, (meth)acrylates having a cyclic skeleton, glycidyl group-containing (meth)acrylates, base) acrylates, hydroxyl-containing (meth)acrylates, substituted amino-containing (meth)acrylates, etc. Here, the "substituted amino group" is as described above.

Examples of the aforementioned alkyl (meth)acrylates include: methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, ( n-butyl methacrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, third butyl (meth)acrylate, amyl (meth)acrylate, (meth)acrylic acid Hexyl ester, heptyl (meth)acrylate, 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 (lauryl (meth)acrylate), (meth)acrylate base) tridecyl acrylate, myristyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate Alkyl esters such as palmityl (meth)acrylate), heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate) etc. The alkyl group is an alkyl (meth)acrylate with a chain structure having 1 to 18 carbon atoms.

Examples of (meth)acrylates having a cyclic skeleton include cycloalkyl (meth)acrylates such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; Aralkyl (meth)acrylate such as benzyl acrylate; cycloalkenyl (meth)acrylate such as dicyclopentenyl (meth)acrylate; dicyclopentenyloxyethyl (meth)acrylate, etc. Cycloalkenyloxyalkyl (meth)acrylate, etc.

As said glycidyl group containing (meth)acrylate, glycidyl (meth)acrylate etc. are mentioned, for example.

Examples of the aforementioned hydroxyl group-containing (meth)acrylate include: hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, (meth)acrylate ) 3-hydroxypropyl acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.

As said substituted amino group containing (meth)acrylate, N-methylamino ethyl (meth)acrylate etc. are mentioned, for example.

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

Examples of the polymer (b) that is at least partly crosslinked by a crosslinking agent and does not have the aforementioned energy ray-curable groups include, for example, polymerization in which the reactive functional group in the aforementioned polymer (b) reacts with a crosslinking agent. thing.

The aforementioned reactive functional group may be appropriately selected according to the type of crosslinking agent and the like, and is not particularly limited. For example, when the crosslinking agent is a polyisocyanate compound, the reactive functional group includes a hydroxyl group, a carboxyl group, an amino group, and the like, and among them, a hydroxyl group having high reactivity with an isocyanate group is preferable. In addition, when the crosslinking agent is an epoxy-based compound, examples of the reactive functional group include carboxyl groups, amine groups, and amido groups. Among them, those with high reactivity with epoxy groups are preferred. The carboxyl group. However, the aforementioned reactive functional group is preferably a group other than a carboxyl group from the viewpoint of preventing corrosion of a semiconductor wafer or a circuit of a semiconductor wafer.

As a polymer (b) which has the said reactive functional group and does not have an energy-ray curable group, the polymer obtained by polymerizing at least the monomer which has the said reactive functional group is mentioned, for example. In the case of the acrylic polymer (b-1), any one or both of the aforementioned acrylic monomers and non-acrylic monomers listed as monomers constituting the acrylic polymer (b-1) , the monomers having the aforementioned reactive functional groups can be used. As the aforementioned polymer (b) having a hydroxyl group as a reactive functional group, for example, a polymer obtained by polymerizing a hydroxyl-containing (meth)acrylate is exemplified. A polymer obtained by polymerizing a monomer in which one or more hydrogen atoms of the aforementioned acrylic monomer or non-acrylic monomer are replaced by the aforementioned reactive functional group.

In the aforementioned polymer (b) having a reactive functional group, the ratio (content) of the amount of structural units derived from a monomer having a reactive functional group relative to the total amount of structural units constituting the polymer (b) is relatively small. Preferably, it is 1 mass % to 20 mass %, More preferably, it is 2 mass % to 10 mass %. When the ratio is in such a range, the degree of crosslinking in the polymer (b) is in a more preferable range.

The weight average molecular weight (Mw) of the polymer (b) not having an energy ray curable group is preferably 10,000 to 2,000,000 in terms of better film-forming properties of the protective film-forming composition (IV-1), More preferably, it is 100,000 to 1,500,000. Here, the "weight average molecular weight" is as described above.

The polymer (b) not having an energy ray curable group contained in the composition (IV-1) for forming a protective film and the film for forming an energy ray curable protective film may be only one kind, or may be two or more kinds, In the case of two or more types, the combination and ratio of these can be selected arbitrarily.

Examples of the composition (IV-1) for forming a protective film include a composition containing either or both of the aforementioned polymer (a1) and the aforementioned compound (a2). In addition, when the composition for forming a protective film (IV-1) contains the aforementioned compound (a2), it is preferable to further contain a polymer (b) not having an energy ray curable group. In this case, it is also less It is preferable to further contain the aforementioned (a1). In addition, the composition for forming a protective film (IV-1) may not contain the aforementioned compound (a2), and may also contain the aforementioned polymer (a1) and a polymer having no energy ray curable group. Polymer (b).

When the protective film forming composition (IV-1) contains the aforementioned polymer (a1), the aforementioned compound (a2) and the polymer (b) having no energy ray curable group, the protective film forming composition ( In IV-1), the content of the aforementioned compound (a2) is preferably 10 to 400 parts by mass relative to 100 parts by mass of the total content of the polymer (a1) and the polymer (b) not having an energy-ray-curable group. parts by mass, more preferably 30 to 350 parts by mass.

In the protective film forming composition (IV-1), the total content of the aforementioned energy ray curable component (a) and the polymer (b) not having an energy ray curable group (that is, energy ray curable protective film formation The ratio of the total content of the energy ray curable component (a) and the polymer (b) not having an energy ray curable group) in the film to the total content of the components other than the solvent is preferably 5% by mass to 90% by mass. % by mass, more preferably 10% by mass to 80% by mass, especially preferably 20% by mass to 70% by mass. The energy ray curability of the film for energy ray curable protective film formation becomes more favorable by making the said ratio of content of an energy ray curable component into such a range.

The composition for forming a protective film (IV-1) may contain, in addition to the aforementioned energy ray curable components, a group selected from thermosetting components, photopolymerization initiators, fillers, coupling agents, and crosslinking agents according to purposes. 1 or more of the group consisting of , coloring agent and general-purpose additives. For example, by using a protective film containing the aforementioned energy ray curable components and thermosetting components Forming composition (IV-1), the formed film for forming an energy ray curable protective film has improved adhesive force to an adherend by heating, and the protective film formed of the film for forming an energy ray curable protective film strength is also increased.

Examples of the aforementioned thermosetting components, photopolymerization initiators, fillers, coupling agents, crosslinking agents, colorants, and general additives in the protective film forming composition (IV-1) include: With the thermosetting component (B), photopolymerization initiator (H), filler (D), coupling agent (E), crosslinking agent (F), colorant (I) in the composition (III-1) ) and the same compound as the general additive (J).

In the protective film forming composition (IV-1), the aforementioned thermosetting components, photopolymerization initiators, fillers, coupling agents, crosslinking agents, colorants, and general additives may be used alone or in combination. Two or more, and when two or more are used together, the combination and ratio of these can be selected arbitrarily.

The contents of the thermosetting components, photopolymerization initiators, fillers, coupling agents, crosslinking agents, colorants, and general-purpose additives in the protective film forming composition (IV-1) may be appropriately adjusted according to the purpose, and No particular limitation.

It is preferable that the composition for protective film formation (IV-1) further contains a solvent in order to improve the handleability of this composition 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).

The solvent contained in the composition (IV-1) for protective film formation may be only 1 type, and may be 2 or more types.

<<Manufacturing method of energy ray curable protective film forming composition>>

An energy ray-curable protective film-forming composition such as the protective film-forming composition (IV-1) can be obtained by preparing each component constituting the composition.

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

In the case of using a solvent, it can be used by mixing the solvent with any formulation component other than the solvent and diluting the formulation component in advance; it can also be used by not using the solvent Any one of the other formulation components is diluted in advance and the solvent is mixed with the formulation components.

There are no particular limitations on the method of mixing the ingredients during preparation, and it is sufficient to select from the following known methods: a method of mixing by rotating a stirring bar or a stirring blade; a method of mixing by using a mixer; and mixing by applying ultrasonic waves. method etc.

The temperature and time for adding and mixing the components are not particularly limited as long as the components are not degraded, and may be appropriately adjusted. The temperature is preferably 15°C to 30°C.

○ Coating

Regarding the aforementioned coating, as long as the surface roughness Ra of the surface of the coating on the side opposite to the side in contact with the support sheet is smaller than that of the support sheet with the coating The surface roughness Ra of the surface on the side of the layer is not particularly limited.

As the aforementioned coating layer, for example, a coating layer containing a cured product obtained by curing by irradiating energy rays is preferable, and a coating composition containing an energy ray polymerizable compound that is polymerized by irradiating energy rays is preferably cured and obtain the coating. Furthermore, the aforementioned energy ray polymerizable compound is preferably (meth)acrylic acid or a derivative thereof.

The above-mentioned composite sheet for forming a protective film not only has the function of being formed to protect the back surface of the diced semiconductor wafer, but also has a function as a dicing sheet when dicing the semiconductor wafer, for example. In addition, when dicing a semiconductor wafer, the semiconductor wafer to which the composite sheet for forming a protective film is attached may be stretched. In this case, the composite sheet for forming a protective film is required to have moderate flexibility. In order to impart appropriate flexibility to the composite sheet for protective film formation, for example, a soft resin such as polypropylene may be selected as a material constituting the support sheet. On the other hand, such soft resins and the like may be deformed or wrinkled by heating. Therefore, it can be said that the coating is preferably formed by hardening the composition used as a raw material by irradiating energy rays, rather than thermally hardening.

The thickness of the aforementioned coating is not particularly limited, and is preferably 0.1 μm to 20 μm, more preferably 0.4 μm to 15 μm, and most preferably 0.8 μm to 10 μm. When the thickness of the coating layer is equal to or greater than the aforementioned lower limit value, the surface roughness Ra of the surface of the coating layer opposite to the side in contact with the aforementioned support sheet becomes easier to reduce, further suppressing the aforementioned composite sheet for protective film formation. The effect of adhesion becomes higher. In addition, by the thickness of the coating being below the aforementioned upper limit, When the state of the semiconductor wafer to which the protective film forming composite sheet is attached is inspected by an infrared camera or the like through the sheet, a clearer inspection image can be obtained, and the semiconductor wafer can be more easily diced along with stretching.

Furthermore, since the coating covers the concave-convex surface of the support sheet as described above, the contact surface with the support sheet can become a concave-convex surface, and the thickness of the coating layer can be as large as The tip of the convex portion is calculated as a common point.

The surface roughness Ra of the surface of the coating layer opposite to the side in contact with the support sheet is preferably at most 0.5 μm, more preferably at most 0.4 μm, further preferably at most 0.3 μm, and most preferably at most 0.2 μm. the following. When the said surface roughness Ra of a coating layer is below the said upper limit, laser printing can be performed more clearly on a protective film.

In addition, the lower limit value of the surface roughness Ra of the surface of the coating layer on the side opposite to the side in contact with the support sheet is not particularly limited, and may be 0.005 μm or the like, for example.

That is, the above-mentioned surface roughness Ra can be, for example, preferably set at 0.005 μm to 0.5 μm, more preferably at 0.005 μm to 0.4 μm, further preferably at 0.005 μm to 0.3 μm, and most preferably at 0.005 μm to 0.2 μm or less.

The above-mentioned surface roughness Ra of the coating layer can be determined by, for example, the surface roughness Ra of the surface of the support sheet having the coating layer, the thickness of the coating layer, the coating method of the coating composition described later for forming the coating layer, etc. Make adjustments.

Regarding the aforementioned coating, the value of [thickness of coating (μm)]/[surface roughness Ra (μm) of the surface of the side having the coating in the support sheet] is preferably from 0.1 to 30, more preferably from 0.3 to 20, preferably 0.5 to 10. The surface roughness Ra of the surface on the opposite side to the side in contact with the said support sheet in a coating layer becomes smaller by the said value being more than the said lower limit value. Therefore, laser printing can be performed on the protective film more clearly, and the effect of suppressing the blocking of the above-mentioned composite sheet for forming a protective film becomes higher. Moreover, since the said value is below the said upper limit, it can avoid that the thickness of a coating layer becomes too thick.

The gloss value of the surface of the coating layer opposite to the side in contact with the aforementioned support sheet (the aforementioned support sheet side) is preferably 32 to 95, more preferably 40 to 90, particularly preferably 45 to 85, for example, 50 to 80. When the above-mentioned 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 aforementioned gloss value of the coating layer is greater than the aforementioned lower limit value, when the state of the semiconductor wafer to which the aforementioned protective film forming composite sheet is pasted is detected by an infrared camera or the like through the aforementioned sheet, a clearer image can be obtained. Detect images. In addition, when the gloss value of the coating is below the upper limit, similarly detecting the state of the semiconductor wafer can prevent the coating from shining, making it easier to visually recognize the detection image using an infrared camera or the like.

In addition, the aforementioned gloss value is a value obtained by measuring the 20° specular gloss of the coating surface from the side opposite to the support sheet side of the coating according to JIS K 7105.

Measurement of Haze from the Coating Side of the Composite Sheet for Protective Film Formation The value is preferably 47% or less, more preferably 1% to 47%, further preferably 2% to 40%, especially preferably 3% to 30%. When the said haze of the composite sheet for protective film formation is below the said upper limit, scattering of light can be suppressed, and laser printing can be performed on a protective film more clearly. In addition, when the state of the semiconductor wafer to which the protective film forming composite sheet is attached is detected by an infrared camera or the like through the sheet, a clearer detection image can be obtained. Here, the measured value of the aforementioned haze of the composite sheet for protective film formation means that, with respect to the composite sheet for protective film formation, it is measured from the direction of the surface of the coating layer opposite to the side in contact with the support sheet. the haze value.

In addition, the said haze is the value measured based on JISK7136.

Various properties such as the gloss value of the aforementioned coating layer can be adjusted by, for example, the thickness of the coating layer, the ingredients contained in the coating composition described below for forming the coating layer, and the like.

The measured value of the haze from the coating side of the composite sheet for forming a protective film can be measured, for example, from the thickness of each layer constituting the composite sheet for forming a protective film, such as a coating layer or a support sheet, and the composition used to form these layers ( For example, the components contained in the coating composition (described later) are adjusted.

<<Coating composition>>

The aforementioned coating composition is preferably any one or both of silica sol and silica microparticles (α) (hereinafter, sometimes referred to as is "ingredient (α)"), And one or more (β) selected from the group consisting of polyfunctional acrylate monomers and acrylate prepolymers (hereinafter, may be simply referred to as “component (β)”).

[ingredient (α)]

The above-mentioned component (α) is used to reduce the refractive index of the above-mentioned coating layer, and to reduce the curing shrinkage and heat-moisture shrinkage of the above-mentioned protective film-forming composite sheet, thereby suppressing the damage of the protective-film-forming composite sheet due to such shrinkage. produces curls.

Examples of the silica sol in the component (α) include colloidal silica-based silica microparticles dissolved in organic solvents such as alcohols and glycol-derived ethers (cellosolves). The colloidal state is suspended. The average particle size of the above-mentioned suspended silica particles is preferably from 0.001 μm to 1 μm, more preferably from 0.03 μm to 0.05 μm.

The silica microparticles in the component (α) to which the radically polymerizable unsaturated group-containing organic compound is bonded are crosslinked and hardened by irradiation with energy rays.

Examples of the silica fine particles to which a radically polymerizable unsaturated group-containing organic compound is bonded include, for example, silanol groups existing on the surface of the silica fine particle and a radically polymerizable unsaturated group-containing organic compound. The particles formed by reacting the functional groups of the silica particles preferably have an average particle diameter of 0.005 μm to 1 μm. Contains free radically polymerizable unsaturated The above-mentioned functional group in the organic compound of the group is not particularly limited as long as it can react with the above-mentioned silanol group in the silica fine particles.

As a radically polymerizable unsaturated group-containing organic compound which has the said functional group, the compound etc. which are represented by following General formula (1) are mentioned, for example.

(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 one of the following formula (2a) to formula (2f))

Examples of the halogen atom in R ² include a chlorine atom, a bromine atom, and an iodine atom.

Examples of preferable organic compounds containing radically polymerizable unsaturated groups include (meth)acrylic acid, (meth)acryl chloride, 2-isocyanatoethyl (meth)acrylate, (meth) ) glycidyl acrylate, 2,3-iminopropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, (3-(meth)acryloxypropyl)trimethoxysilane, etc.

In the present invention, the above-mentioned radically polymerizable unsaturated group-containing organic compound may be used alone or in combination of two or more.

In the component (α), the silica sol and the silica fine particles to which the organic compound containing a radically polymerizable unsaturated group is bonded may be only one type, or two or more types.

As the component (α), only silica sol may be used, or only the above-mentioned silica fine particles bonded with an organic compound containing a radically polymerizable unsaturated group may be used, or silica sol and the above-mentioned bond may be used in combination. Silica microparticles containing organic compounds containing radically polymerizable unsaturated groups.

The content of the component (α) in the aforementioned coating composition is preferably selected according to the refractive index of the aforementioned support sheet, and it is generally preferred that the content of silicon dioxide derived from the component (α) in the aforementioned coating layer be 20 % by mass to 60% by mass. When the said content of silicon dioxide is more than the said lower limit, the effect of reducing the refractive index of a coating layer and the effect of suppressing generation|occurrence|production of curl in the said composite sheet for protective film formation become higher. In addition, when the aforementioned content of silicon dioxide is not more than the aforementioned upper limit, it becomes easier to form a coating, and the effect of suppressing a decrease in the hardness of the coating becomes higher.

Regarding the refractive index, easiness of formation and hardness of the above-mentioned coating, and inhibition The content of the silicon dioxide derived from the component (α) in the coating layer is more preferably 20% by mass to 45% by mass in order to improve the property of curling in the composite sheet for forming a protective film.

[Ingredient (β)]

The aforementioned component (β) is a main photocurable component that forms the aforementioned coating layer.

The polyfunctional acrylate monomer in the said component ((beta)) will not be specifically limited if it is a (meth)acrylic acid derivative which has 2 or more (meth)acryloyl groups in 1 molecule.

Examples of preferable polyfunctional acrylate monomers 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, dicyclopentyl di(meth)acrylate, hexyl Lactone modified dicyclopentenyl di(meth)acrylate, Ethylene oxide modified phosphate di(meth)acrylate, Allylated cyclohexyl di(meth)acrylate, Isocyanurate Di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate ) acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, tri(acryloxyethyl)isocyanurate, dipentaerythritol penta(meth)acrylate, propionic acid modified Dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone modified dipentaerythritol Alcohol hexa(meth)acrylate, etc.

The acrylate-based prepolymer in the component (β) is not particularly limited as long as it is a photocurable polymer or oligomer using (meth)acrylate.

Examples of preferred acrylate prepolymers include polyester acrylate prepolymers, epoxy acrylate prepolymers, urethane acrylate prepolymers, polyol acrylate prepolymers, and polyol acrylate prepolymers. prepolymers, etc.

As the aforementioned polyester acrylate prepolymer, for example, a prepolymer obtained by obtaining a polyester having hydroxyl groups at both ends of the molecule through a condensation reaction of a polycarboxylic acid and a polyhydric alcohol is exemplified. polymer, using (meth)acrylic acid to esterify the aforementioned hydroxyl groups of the polyester oligomers obtained; to obtain oligomers by adding polycarboxylic acids and alkylene oxides, using (meth)acrylic acid to obtain The terminal hydroxyl groups of the obtained oligomers were esterified.

As the aforementioned epoxy acrylate prepolymer, for example, a prepolymer obtained by making a relatively low molecular weight bisphenol-type epoxy resin or a novolac-type epoxy resin ethylene oxide A ring (oxirane ring) reacts with (meth)acrylic acid to perform esterification.

As the above-mentioned urethane acrylate prepolymer, for example, a prepolymer obtained by obtaining polyurethane by reacting polyether polyol or polyester polyol with polyisocyanate is exemplified. Ester oligomers, using (meth)acrylic acid to esterify the obtained polyurethane oligomers.

As the aforementioned polyol acrylate prepolymer, for example, the A prepolymer obtained by esterifying hydroxyl groups of polyether polyols with (meth)acrylic acid.

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

As the component (β), the aforementioned polyfunctional acrylate monomer may be used alone, or the aforementioned acrylate prepolymer may be used alone, or the aforementioned polyfunctional acrylate monomer and acrylate prepolymer may be used in combination. .

[solvent]

The aforementioned 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 more easily applied and dried to form a coating film for forming a coating layer.

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 dichloride; methanol, ethanol, and propanol. , butanol, 1-methoxy-2-propanol and other alcohols; acetone, methyl ethyl ketone, 2-pentanone, isophorone, cyclohexanone and other ketones; ethyl acetate, butyl acetate and other esters ; 2-ethoxyethanol (ethyl cellosolve) and other cellosolves.

[optional ingredient]

In the above-mentioned coating composition, in addition to the component (α) and the component (β), it may also contain a monofunctional acrylate monomer, a photopolymerization initiator, a photosensitizer Various optional ingredients such as additives, polymerization inhibitors, crosslinking agents, antioxidants, UV absorbers, light stabilizers, leveling agents, and defoamers.

The said arbitrary components may be used individually by 1 type, and may use 2 or more types together.

(Monofunctional acrylate monomer)

The aforementioned monofunctional acrylate-based 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)acryl group in one molecule. .

Examples of preferred monofunctional acrylate monomers include cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate ( Lauryl (meth)acrylate), stearyl (meth)acrylate (stearyl (meth)acrylate), isobornyl (meth)acrylate, and the like.

(photopolymerization initiator)

As the said photoinitiator of an arbitrary component, the well-known photoinitiator conventionally used for a radical polymerization is mentioned.

Examples of preferable photopolymerization initiators include acetophenone-based compounds, benzophenone-based compounds, alkylaminobenzophenone-based compounds, benzoyl-based compounds, benzoin-based compounds, and benzoin-based compounds. Ether compound aryl ketone photopolymerization initiators such as compounds, benzoyl dimethyl ketal compounds, benzoyl benzoate compounds, α-acyl oxime ester compounds, etc.; thioether compounds, thioxanthone Sulfur-containing photopolymerization initiators, such as sulfur-based compounds; acyl-based phosphine oxide-based compounds such as acyl-diarylphosphine oxides; anthraquinone-based compounds, etc.

In addition, when hardening the said coating composition by irradiating an electron beam, a photoinitiator is unnecessary.

In the aforementioned coating composition, the content of the photopolymerization initiator is preferably 0.2 to 10 parts by mass, more preferably 0.5 to 7 parts by mass relative to 100 parts by mass of the total content of the photocurable components.

(photosensitizer)

Examples of the photosensitizer include tertiary amines, p-dimethylaminobenzoate, and thiol-based sensitizers.

In the aforementioned coating composition, the content of the photosensitizer is preferably 1 to 20 parts by mass, more preferably 2 to 10 parts by mass relative to 100 parts by mass of the total content of the photocurable components.

(antioxidant, UV absorber, light stabilizer)

The aforementioned antioxidant, ultraviolet absorber, and light stabilizer may be known compounds, but are preferably reactive antioxidants, ultraviolet absorbers, and light stabilizers having (meth)acryl groups in the molecule. These antioxidants, UV absorbers and photostabilizers are bonded to the On the polymer chain of the composition, it can inhibit the escape from the hardening layer over time, so that the function of these components can be exerted for a long time.

The aforementioned coating composition preferably contains silica sol as the component (α), more preferably a silica sol containing silica microparticles suspended in a colloidal state and having an average particle diameter of 0.03 μm to 0.05 μm.

When the coating layer contains such a silica sol, the effect of suppressing the blocking of the protective film-forming composite sheet becomes higher. In addition, in the above-mentioned coating layer, such silica sol is more concentrated on the surface opposite to the support sheet side or its vicinity than in other regions, thereby suppressing the formation of the protective film-forming composite sheet. The effect of adhesion becomes higher. In the above-mentioned coating layer, the coating conditions of the above-mentioned coating composition may be adjusted so that the components such as silica sol and the like are segregated.

<<Manufacturing method of coating composition>>

The coating composition can be obtained, for example, by using energy ray polymerizable compounds such as component (α) and component (β), and components other than these energy ray polymerizable compounds, etc., as necessary to form a coating. The components of the cloth composition are formulated. The coating composition can be obtained, for example, by the same method as that of the above-mentioned adhesive composition except that the ingredients are different.

In the case of using a solvent, it can be used by mixing the solvent with any formulation component other than the solvent and diluting the formulation component in advance; it can also be used by not using the solvent Any one of the other formulation components is diluted in advance and the solvent is mixed with the formulation components.

Components other than the solvent in the coating composition may be dissolved or dispersed without being dissolved. In addition, the concentration and viscosity of each component in the coating composition are not particularly limited as long as the coating composition can be applied.

◎Manufacturing method of composite sheet for protective film formation

The composite sheet for forming a protective film of the present invention can be produced by forming a film for forming a protective film using the above-mentioned composition for forming a protective film, forming a coating layer using the above-mentioned coating composition, and laminating the coating layers in this order. , a support sheet, and a film for forming a protective film. When the support sheet is composed of plural layers, the support sheet may be produced by laminating these plural layers. For example, when the support sheet is formed by laminating a substrate and an adhesive, the adhesive layer may be formed using the aforementioned adhesive composition.

The formation order of each layer (coating layer, support sheet, film for protective film formation) which comprises the composite sheet for protective film formation is not specifically limited. Furthermore, when these layers are formed from the composition, they may be formed directly on the surface of the adjacent layer in the state of the composite sheet for forming a protective film, or a release film (release sheet) may be used separately on the release film (release sheet). ) is formed on the surface of the film, and the formed layer is bonded to the surface of the adjacent layer in the state of the composite sheet for forming a protective film. However, in order to suppress the formation of voids between the coating layer and the concave-convex surface (back surface) of the support sheet, it is preferable to directly apply the coating composition to the concave-convex surface of the support sheet to form the coating layer.

Hereinafter, an example of a preferable manufacturing method of the composite sheet for protective film formation is demonstrated.

The coating is preferably formed by applying a coating composition to the concave-convex surface of the support sheet (the back surface 10b of the support sheet 10 in FIGS. and dry it, and if necessary, harden the formed coating film.

What is necessary is to apply the coating composition to the target surface by a known method, for example, the method of using the following various coating machines: air knife coater, knife coater, rod coater, gravure coater, Roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, wire rod coater, contact coater, etc. .

When the coating composition is applied to the concave-convex surface of the support sheet, it is preferable to suppress generation of voids between the coating layer and the concave-convex surface of the support sheet. By suppressing the occurrence of the aforementioned voids, diffuse reflection of light at the boundary between the coating layer and the concave-convex surface of the support sheet can be suppressed, and laser printing can be performed on the surface of the protective film more clearly.

In order to suppress the occurrence of the aforementioned voids, for example, it is preferable to use a coating composition with low viscosity. In addition, a coating composition containing an energy ray polymerizable compound is generally suitable for suppressing the generation of the aforementioned voids.

The drying conditions of the coating composition are not particularly limited, but the coating composition is preferably heat-dried, and in this case, for example, it is preferably dried under the conditions of 70° C. to 130° C. for 0.5 minutes to 5 minutes.

The curing conditions of the coating film formed from the coating composition are not particularly limited, and may be performed by known methods.

In the case of hardening by irradiating energy rays, such as when irradiating ultraviolet rays, use a high-pressure mercury lamp, a fusion H-type lamp, a xenon lamp, a black light lamp, or an LED lamp as an ultraviolet source, and set the irradiation amount to preferably 100mJ/ cm ² to 500mJ/cm ² can be irradiated. On the other hand, when irradiating electron beams, an electron beam is generated by an electron beam accelerator or the like, and the irradiation amount may be preferably 150 kV to 350 kV and irradiated. Among them, it is preferable to form a coating layer by irradiating ultraviolet rays.

In the case where the support sheet is formed by laminating the substrate and the adhesive, the adhesive layer can be directly coated on the surface of the substrate with the coating (surface 11a of the substrate 11 in Figures 1 and 2). agent composition. However, it is generally preferable to use the method of forming an adhesive layer separately in advance and attaching the adhesive layer to the surface of the substrate: for example, applying an adhesive composition to the release-treated surface of the release sheet and drying it, Thereby, an adhesive layer is formed, the formed adhesive layer is bonded to the surface of the substrate, and the release sheet is removed.

The adhesive composition can be applied to the target surface by the same method as in the case of applying the composition.

The applied adhesive composition can be cross-linked by applying heat, which benefits Crosslinking by heating can also be carried out together with drying. The heating conditions may be, for example, 100° C. to 130° C. and 1 minute to 5 minutes, but are not limited thereto.

In either case where the support sheet is composed of only one layer (single layer) such as a base material, and in any case where the support sheet is composed of multiple layers such as a base material and an adhesive laminated, etc., the The surface of the coated support sheet (in FIGS. 1 and 2, the surface 10a of the support sheet 10, that is, the surface 12a of the adhesive layer 12) is directly coated with the composition for forming a protective film to form a film for forming a protective film. However, it is generally preferable to employ the following method of separately forming a protective film-forming film in advance and attaching the protective film-forming film to the surface of the support sheet in the same manner as in the case of the above-mentioned adhesive layer: peeling treatment of the release sheet The composition for forming a protective film is applied on the surface and dried to form a film for forming a protective film, the formed film for forming a protective film is bonded to the surface of the support sheet, and the release sheet is removed if necessary.

The composition for forming a protective film is applied to the target surface by the same method as in the case of applying the composition.

The drying conditions of the protective film forming composition are not particularly limited, and drying can be performed by the same method as in the case of the coating composition.

When the support sheet is formed by laminating a base material and an adhesive agent, the composite sheet for protective film formation of the present invention can also be produced by a method other than the above-mentioned method. For example, a composite sheet for forming a protective film can also be produced by forming an adhesive layer using the aforementioned adhesive composition and using After forming a film for forming a protective film with the composition for forming a protective film, the adhesive layer and the film for forming a protective film are laminated to form a laminate, and the surface of the adhesive layer of the laminate (not the surface of the adhesive layer) The surface on which the film for protective film formation is provided) is bonded to the surface of the base material provided with the coating layer (the surface 11a of the base material 11 in FIGS. 1 and 2 ).

The formation conditions of the pressure-sensitive adhesive layer and the film for protective film formation in this case are the same as the case of the said method.

For example, when manufacturing a composite sheet for forming a protective film as shown in FIG. 1 , that is, when the composite sheet for forming a protective film is viewed from above, the surface area of the film for forming a protective film is smaller than that of the adhesive layer. In the case of a sheet, in the above-mentioned production method, a film for forming a protective film cut into a predetermined size and shape in advance may be provided on the adhesive layer.

◎How to use the composite sheet for protective film formation

The usage method of the composite sheet for protective film formation of this invention is as follows, for example.

First, the usage method of the composite sheet for protective film formation when the film for protective film formation is thermosetting is demonstrated.

In this case, first, the film for protective film formation of the composite sheet for protective film formation is attached to the back surface of a semiconductor wafer, and the composite sheet for protective film formation is fixed to a dicing apparatus.

Next, the film for protective film formation is hardened by heating, and a protective film is produced. A back grinding tape is attached to the surface (electrode formation surface) of the semiconductor wafer In this case, usually the back grinding tape is removed from the semiconductor wafer to form a protective film.

Then, the semiconductor wafer is diced to produce semiconductor wafers. From the formation of the protective film to cutting, the protective film can be irradiated with laser light from the coating side of the composite sheet for protective film formation to print on the surface of the protective film. In this case, as described above, the surface roughness Ra of the surface (rear surface) of the coating layer opposite to the side in contact with the support sheet is sufficiently small, and the aforementioned rear surface of the coating layer is a smooth surface or has unevenness. suppressed face. Therefore, when laser light is irradiated, diffuse reflection of the laser light on the back surface of the coating layer can be suppressed, and laser printing can be clearly performed on the protective film.

In addition, with regard to the semiconductor wafer before dicing or the semiconductor wafer obtained after dicing, infrared camera or the like may be used to inspect the surface of the semiconductor wafer or semiconductor wafer from the back side (the surface to which the protective film forming composite sheet is attached) side. Make observations to detect status. For example, in the case of a semiconductor wafer, the semiconductor wafer may be inspected for damage such as a chip or a crack.

On the other hand, in the semiconductor wafer with a protective film of the present invention, as described above, the surface roughness Ra of the surface (back surface) of the coating layer opposite to the side in contact with the support sheet is sufficiently small to further suppress Voids are formed between the coating layer and the uneven surface (back surface) of the support sheet. Therefore, when a semiconductor wafer or a semiconductor wafer is observed from the coating side through the composite sheet for forming a protective film with an infrared camera or the like, a clear inspection image can be obtained, and thus inspection can be performed with high precision.

Then, the semiconductor wafer is peeled off and picked up together with the protective film attached to the back surface of the semiconductor wafer from the support sheet, whereby a semiconductor wafer with a protective film is obtained. For example, when the support sheet is formed by laminating a base material and an adhesive, and the adhesive layer is energy ray curable, the adhesive layer is cured by irradiating energy rays, and the cured adhesive layer The semiconductor wafer is picked up together with the protective film attached to the back surface of the semiconductor wafer, thereby obtaining the semiconductor wafer with the protective film more easily.

For example, in the case of using the protective film forming composite sheet 1 shown in FIG. (Adhesive layer 12 ) is attached to jigs (not shown) for dicing such as ring frames, and the composite sheet 1 for protective film formation is fixed to a dicing device. Next, after hardening the protective film forming film 13 to form a protective film, laser printing is performed on the protective film, and then cutting is performed. If necessary, by irradiating energy rays, the adhesive layer 12 is debonded to the aforementioned treatment. The area other than the part of the tool is hardened, and then the semiconductor chip with the protective film can be picked up. Thus, when the adhesive layer 12 is used as the energy ray curable protective film forming composite sheet 1, it is necessary to prevent the protective film forming composite sheet 1 from the aforementioned jig and to prevent the specific adhesive layer 12 from being peeled off. Adjustment is made in the form of area hardening. On the other hand, when using the composite sheet 1 for protective film formation, it is not necessary to separately provide the structure for sticking the composite sheet 1 for protective film formation to the said jig.

On the other hand, when using the composite sheet 2 for protective film formation shown in FIG. The adhesive 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 the dicing device. Next, after curing the protective film-forming film 23 to form a protective film, laser printing is performed on the protective film, and then cutting is performed. If necessary, the adhesive layer 12 is cured by irradiating energy rays, and then the protective film is picked up. semiconductor chips. In this way, when the adhesive layer 12 is used as the energy ray curable protective film forming composite sheet 2, unlike the case of using the protective film forming composite sheet 1, it is not necessary to prevent the specific region of the adhesive layer 12 from being cured. adjusted in a manner. On the other hand, unlike the composite sheet 1 for protective film formation, the composite sheet 2 for protective film formation must have the adhesive agent layer 16 for jigs. By providing the adhesive layer 16 for a jig, the adhesive layer 12 can select a composition from a wide range according to the objective.

Next, how to use the composite sheet for protective film formation when the film for protective film formation is energy ray curable is demonstrated.

In this case, first, as in the case where the film for forming a protective film is thermosetting, the back surface of the semiconductor wafer is attached to the film for forming a protective film of the composite sheet for forming a protective film, and the composite for forming a protective film is The sheet is secured to the cutting device.

Next, the film for protective film formation was hardened by irradiating an energy ray, and the protective film was produced. On the surface (electrode formation surface) of the semiconductor wafer, a backside grinding In the case of a grinding tape, a protective film is usually formed after the back grinding tape is removed from the semiconductor wafer.

Then, the semiconductor wafer is diced to produce semiconductor wafers. From the formation of the protective film to cutting, the protective film can be irradiated with laser light from the coating side of the composite sheet for protective film formation to print on the surface of the protective film. The process from printing to cutting can be carried out in the same manner as in the above-mentioned case where the film for forming a protective film is thermosetting, and similarly to this case, laser printing can be clearly performed on the protective film, and it is possible to use an infrared camera. and other high-precision detection.

Then, the semiconductor wafer is peeled off and picked up together with the protective film attached to the back surface of the semiconductor wafer from the support sheet, whereby a semiconductor wafer with a protective film is obtained.

This method is particularly preferable when, for example, a composite sheet for forming a protective film is used as a composite sheet in which a support sheet is laminated with a substrate and an adhesive, and the adhesive layer is non-energy ray curable. Furthermore, here, the case where the film for forming a protective film is cured by irradiating energy rays is described, and then the semiconductor wafer is diced and the semiconductor wafer with the protective film is picked up. However, the adhesive layer is not hardened by energy rays. In the specific case, the film for protective film formation may be cured by irradiating energy rays at any stage before picking up the semiconductor wafer.

For example, when using a support sheet laminated with a base material and an adhesive, and When the aforementioned adhesive layer is an energy ray curable protective film forming composite sheet, the method described below is preferable.

That is, first, similarly to the above case, the film for protective film formation of the composite sheet for protective film formation is attached to the back surface of the semiconductor wafer, and the composite sheet for protective film formation is fixed to the dicing apparatus.

Next, laser light was irradiated to the protective film from the coating side of the composite sheet for protective film formation, the surface of the protective film was printed, and the semiconductor wafer was further diced to obtain a semiconductor wafer. The process from printing to cutting can be carried out in the same manner as in the above-mentioned case where the film for forming a protective film is thermosetting, and similarly to this case, laser printing can be clearly performed on the protective film, and it is possible to use an infrared camera. and other high-precision detection.

Next, by irradiating energy rays to harden the film for forming a protective film to form a protective film, and harden the adhesive layer, the semiconductor wafer and the protective film attached to the back surface of the semiconductor wafer are bonded from the hardened adhesive layer. film together, thereby obtaining a semiconductor wafer with a protective film.

On the other hand, when winding up a long composite sheet for protective film formation, it is usually used in a state where a release film (release film 15 in FIGS. 1 and 2 ) is laminated on the exposed surface of the film for protective film formation. Composite sheet for protective film formation. And, regardless of the composition of the protective film forming composite sheet of the present invention (for example, any one of the protective film forming composite sheet 1 shown in FIG. 1 and the protective film forming composite sheet 2 shown in FIG. 2 ), The composite sheet for forming the protective film is rolled into a roll shape, and the coating layer, the support sheet, and the protective film are laminated in sequence. The lamination units of the forming film and the peeling film are stacked sequentially along the radial direction of the roller. 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 where the film for forming a protective film is provided) and the surface of the other laminated unit The back surface of the coating layer (the surface opposite to the side in contact with the substrate) is in contact with and pressed, and the roll of the composite sheet for forming a protective film is stored in this state as it is. However, since the adhesion of the release film and the coating layer between the laminated units can be suppressed by providing the coating layer, the adhesion of the composite sheet for protective film formation of the present invention is suppressed.

The composite sheet for forming a protective film of the present invention with a width of 50 mm and a length of 100 mm in a state where a release film is provided on the film for forming a protective film is stacked so that all the coatings face the same direction and the total thickness of the coatings becomes 10 μm to 60 μm A plurality of sheets, thereby making a laminate in which one outermost layer is a coating layer and the other outermost layer is a release film, and the laminate is applied with 980.665mN (that is, 100gf ) force (external force) after standing at 40°C for 3 days, peel off the film closest to the outermost coating in the lamination direction at the peeling speed of 300mm/min and the peeling angle of 180° , peeling from the adjacent coating (the coating closest to the outermost coating in the lamination direction), the peeling force at this time is preferably 10mN/50mm or less, more preferably 7.5mN/50mm or less, especially 5mN/50mm or less. In addition, all the composite sheets for protective film formation of the several sheets piled up here have the same structure. Moreover, it is preferable that the number of laminated composite sheets for protective film formation is 10 sheets. Formation of the protective film of the present invention can be confirmed from the peeling force of such a peeling film The level of anti-blocking effect (blocking resistance) of the composite sheet.

[Example]

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

<Manufacture of composite sheet for protective film formation> [Example 1]

The composite sheet for protective film formation of the structure shown in FIG. 1 was manufactured. A plan view of the composite sheet for forming a protective film is shown in FIG. 3 . More specifically, as follows.

[Manufacturing of the first laminate] (Preparation of thermosetting protective film-forming composition)

The following components were prepared in the following amounts (solid content), and methyl ethyl ketone was further prepared to obtain a composition (III-1) for forming a protective film with a solid content concentration of 51% by mass.

(polymer component (A))

(A)-1: Acrylic resin 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 (400000 weight average molecular weight, glass transition temperature -1 degreeC) 150 mass parts.

(thermosetting component (B)) ‧Epoxy resin (B1)

(B1)-1: 60 parts by mass of bisphenol A type epoxy resin ("JER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 183g/eq to 194g/eq, molecular weight 370).

(B1)-2: 10 parts by mass of bisphenol A type epoxy resin ("JER1055" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 800g/eq to 900g/eq, molecular weight 1600).

(B1)-3: 30 parts by mass of a dicyclopentadiene-type epoxy resin ("Epiclon HP-7200HH" manufactured by DIC Corporation, epoxy equivalent weight: 274 g/eq to 286 g/eq).

‧Thermal curing agent (B2)

(B2)-1: 2 parts by mass of dicyandiamide (solid dispersion type latent curing agent, "Adeka Hardener EH-3636AS" manufactured by ADEKA Corporation, active hydrogen content: 21 g/eq).

(hardening accelerator (C))

(C)-1: 2 parts by mass of 2-phenyl-4,5-dihydroxymethylimidazole ("Curezol 2PHZ" manufactured by Shikoku Chemical Industry Co., Ltd.).

(Filler (D))

(D)-1: 320 parts by mass of a silica filler ("SC2050MA" of Admatechs, surface-modified with an epoxy-based compound, average particle size: 0.5 μm).

(Coupling agent (E))

(E)-1: γ-glycidoxypropyltrimethoxysilane (silane coupling agent, "KBM403" manufactured by Shin-Etsu Chemical Co., Ltd., methoxy equivalent 12.7mmol/g, molecular weight 236.3) 0.4 parts by mass.

(colorant (I))

(I)-1: 1.2 parts by mass of carbon black (pigment, "MA600B" manufactured by Mitsubishi Chemical Corporation, average particle diameter: 28 nm).

(Formation of film for protective film formation, production of first laminate)

The protective film-forming composition (III-1) obtained above was coated on the release-treated surface of the first release film ("SP-P502010*" manufactured by Lintec Corporation, thickness 50 μm) using a knife coater, It dried at 120 degreeC for 2 minutes, and formed the film (thickness 25 micrometers) for protective film formation.

Next, the release-treated surface of the second release film ("SP-PET381031C" manufactured by Lintec Co., Ltd., thickness 38 μm) was attached to the surface opposite to the surface on which the first release film was provided in the film for forming a protective film. , A long laminate in which the first release film, the film for protective film formation, and the second release film were sequentially laminated was obtained. Next, after winding up the elongated laminated body into a roll, the laminated body is cut in the width direction of the laminated body (the width indicated by symbol w1 in the protective film forming composite sheet ₁ shown in FIG. 3 ). direction) is 300mm in size.

Then, with respect to the laminated body cut out, in the width direction central part of the laminated body, from the second peeling film side, the second peeling film and the protective film forming film are drawn together in a circular shape with a diameter of 220 mm in plan view. The half cut of the incision is performed in this way. In addition, the "plan view" of a laminate in this specification means looking down at the laminate from above in the lamination direction of a laminate. Then, the second release film and the film for forming a protective film are removed from the above-mentioned laminate so that only the circular portion formed by the half-cut remains, thereby obtaining sequentially on the release-treated surface of the first release film. The 1st laminated body which laminated|stacked the film for protective film formation which is circular in planar view, and the 2nd release film. The circular protective film forming film in this first laminate corresponds to the circular protective film forming film 13 having _a diameter d1 of 220 mm in the protective film forming composite sheet 1 shown in FIG. 3 .

(Preparation of coating composition)

Dispersion liquid obtained by dispersing silica sol in 2-ethoxyethanol (ethyl cellosolve) ("OSCAL1632" manufactured by Catalyst Chemical Industry Co., Ltd., the particle size of silica sol is 30nm to 50nm, solid 150 parts by mass of urethane acrylate and polyfunctional acrylate monomers ("BEAMSET 575CB" manufactured by Arakawa Chemical Industry Co., Ltd., solid content concentration 100 % by mass, containing a photopolymerization initiator) 100 parts by mass to obtain a coating composition (solid content concentration: 30% by mass).

(formation of coating)

Next, using a wire bar coater, the surface roughness Ra on the concave-convex surface was 0.4 μm, and the surface roughness Ra on the side opposite to the concave-convex surface was 0.02 μm. Polypropylene substrate (thickness 100 μm , with a melting point of 140°C to 160°C), apply the coating composition obtained above, dry at 80°C for 1 minute, and then irradiate ultraviolet light with a light intensity of about 230mJ/ ^cm2 to harden the dried coating film , forming a coating (thickness 3 μm).

(Preparation of Adhesive Composition)

Prepare 100 parts by mass of alkyl (meth)acrylate copolymer and 10 parts by mass (solid content) of aromatic polyisocyanate compound (crosslinking agent, "Takenate D110N" manufactured by Mitsui Chemicals Co., Ltd.), and further prepare methyl Ethyl ketone was used to obtain an adhesive composition (iii) with a solid content concentration of 30% by mass.

The aforementioned alkyl (meth)acrylate copolymer is made 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. The weight average molecular weight is 600000 Acrylic resin.

(Formation of adhesive layer (support sheet), production of second laminate)

A third release film made of polyethylene terephthalate film with a thickness of 38 μm (manufactured by Lintec Co. "SP-PET381031C") was coated with the adhesive composition (iii) obtained above and dried to form an adhesive layer (thickness: 5 μm) on the peeling-treated surface.

Next, corona treatment is performed on the surface opposite to the concave-convex surface of the above-mentioned substrate on which the coating is formed, and the above-mentioned adhesive layer is attached to the corona-treated surface to obtain a coating, a substrate, and an adhesive. The layer and the third release film are laminated in this order, and the second laminate includes a long strip of the support sheet.

Next, after winding up the elongated second laminated body into a roll, the second laminated body is cut into the width direction of the second laminated body (in the protective film forming composite sheet 1 shown in FIG. The direction of the width indicated by w ₁ ) is 300mm in size.

(Manufacture of composite sheets for protective film formation)

The 2nd release film was removed from the 1st laminate obtained above, and the circular film for protective film formation was exposed. Moreover, the 3rd peeling film was removed from the 2nd laminate obtained above, and the adhesive layer was exposed. Then, the exposed surface of the film for forming a protective film is bonded to the exposed surface of the adhesive layer to obtain a coating layer, a base material, an adhesive layer, a film for forming a protective film, and a first release film in this order. The third laminate of the laminated protective film forming composite sheet.

With respect to the third laminate obtained above, a half-cut was performed from the coating side to draw a circle with a diameter of 270 mm in plan view on all of the coating layer, base material, and adhesive layer. In this half-cut, the above-mentioned circle with a diameter of 270 mm in plan view is concentric with the circle with a diameter of 220 mm formed by the film for forming a protective film, and all of the coating layer, base material, and adhesive layer are notched.

Then, in a plan view, with respect to the above-mentioned circle with a diameter of 270 mm, at a position 20 mm away from the radially outer side of the circle, the width direction of the third laminate (the composite sheet for forming a protective film shown in FIG. 3 ) was drawn. In 1, in the way of a pair of circular arcs facing each other in the direction of the width indicated by the symbol w ₁ , from the coating side, the half-cut of the coating, the base material and the adhesive layer is all cut out. The notches corresponding to the pair of circular arcs form the curved peripheral portion of the adhesive layer indicated by reference numeral 121 in the protective film forming composite sheet 1 shown in FIG. 3 . And the distance (20mm) between the circle of diameter 270mm and the said circular arc corresponds to the code|symbol w2 in the composite sheet ₁ for protective film formation shown in FIG.

Such drawing is carried out at multiple locations in the longitudinal direction of the third laminate (the direction perpendicular to the width direction indicated by the symbol w1 in the protective film forming composite sheet ₁ shown in FIG. 3 ). The above-mentioned half-cut of two concentric circles and a pair of circular arcs is to draw two straight lines connecting the circular arcs in the aforementioned length direction between adjacent parts in a plan view, from the coating side to the coating, the base All materials and adhesive layers are cut in half. The notches corresponding to these two straight lines form the planar peripheral edge portion of the adhesive layer indicated by reference numeral 122 in the composite sheet 1 for protective film formation shown in FIG. 3 .

Then, transfer the coating layer, base material and adhesive layer in the portion between the above-mentioned circle with a diameter of 270 mm and the pair of arcs, and the portion sandwiched by the two straight lines connecting the above-mentioned arcs in a plan view. Thus, the composite sheet for protective film formation shown in FIG. 1 and FIG. 3 was obtained. The circular adhesive layer (support sheet) in this protective film forming composite sheet corresponds to the circular adhesive layer 12 (support sheet 10) whose diameter _d2 is 270 mm in FIG. 3 . In addition, the 1st release film in this composite sheet for protective film formation corresponds to the release film 15 in FIG.

[Example 2]

As shown in Table 1, the surface roughness Ra of the concave-convex surface is 1 μm The composite sheet for protective film formation was obtained by the method similar to Example 1 except the base material of 0.4 micrometers.

[Example 3]

As shown in Table 1, use the same method as in Example 1 except that the surface roughness Ra of the uneven surface is 1 μm instead of 0.4 μm, and the thickness of the coating is set to 1 μm instead of 3 μm. A composite sheet for forming a protective film was obtained.

[Example 4]

As shown in Table 1, the composite sheet for protective film formation was obtained by the method similar to Example 1 except having made the thickness of a coating layer into 1 micrometer instead of 3 micrometers.

[Example 5]

As shown in Table 1, the surface roughness Ra of the concave-convex surface is 1 μm instead of 0.4 μm, and the thickness of the coating is set to 6 μm instead of 3 μm. In the same way as in Example 1, A composite sheet for forming a protective film was obtained.

[Example 6]

As shown in Table 1, use the same method as in Example 1 except that the surface roughness Ra of the concave-convex surface is 3 μm instead of 0.4 μm, and the thickness of the coating is set to 6 μm instead of 3 μm. won A composite sheet for forming a protective film was obtained.

[Comparative example 1]

As shown in Table 1, except that the surface roughness Ra of the uneven surface is 1 μm instead of 0.4 μm, and no coating layer is formed, a composite for forming a protective film is obtained by the same method as in Example 1. piece.

[Comparative example 2]

As shown in Table 1, the base material was arranged so that the concave-convex surface faced the opposite side, that is, the adhesive layer side (inside), and no coating was formed (that is, the conventional configuration shown in FIG. 5 ), except Except for this point, the composite sheet for protective film formation was obtained by the method similar to Example 1.

[Comparative example 3]

As shown in Table 1, use a substrate with a surface roughness Ra of 1 μm instead of 0.4 μm on the concave-convex surface. The coating layer (that is, the conventional structure shown in FIG. 5) was obtained by the method similar to Example 1 except this point, and the composite sheet for protective film formation was obtained.

[Comparative example 4]

Use the same amount of spherical silica ("SC2050MA" manufactured by Admatechs, with an average particle size of 0.5 μm) surface-modified with epoxy groups in the solid content instead of the silica sol component. A coating composition was prepared in the same manner as in Example 1 except for the dispersion liquid dispersed in 2-ethoxyethanol.

And using this coating composition, the composite sheet for protective film formation was obtained by the method similar to Example 1 except this point.

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 Protective Film Formation> [laser printing characteristics]

In the protective film-forming composite sheets obtained above in each of the Examples and Comparative Examples, the first release film was removed, and the adhesive layer was attached using an attaching device ("RAD-2700F/12" manufactured by Lintec Corporation). On a ring frame made of stainless steel, a film for forming a protective film was attached to the back surface of a silicon wafer (8 inches in outer diameter, 100 μm in thickness) heated to 70°C.

Next, the film for protective film formation was heat-processed at 130 degreeC for 2 hours, and the film for protective film formation was thermally hardened and the protective film was formed.

Then, using a printing device ("VK9700" manufactured by KEYENCE Corporation), under the conditions of output 0.6W, frequency 40kHz, and scanning speed 100mm/sec, irradiate the protective film with laser light with a wavelength of 532nm from the substrate side, according to the following Two patterns (pattern 1, pattern 2) are used for laser printing on the protective film.

(pattern)

Pattern 1: The character size is 0.4mm×0.5mm, the character interval is 0.3mm, and the number of characters is 20.

Pattern 2: The character size is 0.2mm×0.5mm, the character interval is 0.3mm, and the number of characters is 20.

Next, the visibility (laser printing properties) from the base material side was evaluated on the characters formed on the protective film by the above-mentioned laser printing according to the following criteria. The results are shown in Table 1.

(evaluation criteria)

A: All the characters of pattern 1 and pattern 2 are clear, and the characters of pattern 1 and pattern 2 can be read without any problem.

B: At least part of the characters in pattern 2 are unclear, but all the characters in pattern 1 are clear, and the characters in pattern 1 can be read without any problem.

C: In either of pattern 1 and pattern 2, at least a part of characters is unclear.

[Blocking resistance (1)]

The protective film-forming composite sheets of the examples and comparative examples obtained above were wound up on ABS (Acrylonitrile-Butadiene-Styrene resin; Acrylonitrile-Butadiene-Styrene resin) resin with a length of 10 m and a diameter of 3 inches. The core material was made, and it left still at room temperature for 3 days in this state.

Next, with regard to the composite sheets for protective film formation of Examples 1 to 6, and Comparative Example 4, it was attempted to roll out a composite sheet in which a coating layer, a base material, an adhesive layer, a film for protective film formation, and a first release film were sequentially laminated. 10 pieces of laminated units, for the composite sheet for protective film formation of Comparative Example 1 to Comparative Example 3, because there is no There was a coating layer, so I tried to roll out 10 laminated units in which the substrate, the adhesive layer, the film for protective film formation, and the first release film were sequentially laminated. Whether or not the contact parts of the composite sheet adhered to each other, and when there was adhesion, the degree of adhesion was evaluated according to the following criteria. The results are shown in Table 1.

(evaluation criteria)

A: Adhesion between the aforementioned contact parts was not confirmed at all.

B: Slight adhesion between the aforementioned contact portions was confirmed, but the composite sheet for forming a protective film could be unwound without any problem.

C: Parts of the contact portions were completely adhered to each other, and when the composite sheet for forming a protective film was unrolled, the first release film was peeled from the adhesive layer.

[Blocking resistance (2)]

The composite sheet for protective film formation of each Example and the comparative example obtained above was cut|disconnected so that it might become the band of the size of width 50mm and length 100mm. Furthermore, when cutting out, the longitudinal direction of the tape is aligned with the application direction of the adhesive composition.

Ten tapes thus obtained were prepared, and these tapes were laminated to form test pieces. At this time, in the cases of Examples 1 to 6 and Comparative Example 4, the above-mentioned tapes were laminated with the coating facing upward. In addition, in the case of Comparative Example 1 to Comparative Example 3, since there was no coating layer, the above-mentioned tapes were laminated with the substrate facing upward. Next, sandwich the test piece between two glass plates (75 mm in width, 15 mm in length, and 5 mm in thickness), place the entire laminate of these glass plates and the test piece on a predetermined position with one glass plate as the lowest layer, and place on another party's most A plumb weight is placed on the upper glass plate to pressurize the aforementioned test piece. At this time, the force applied to the test piece in the lamination direction of the tape was 980.665mN (that is, 100gf). In this state, the entire laminate of these glass plates and the test piece was stored at 40° C. for 3 days in a humid heat accelerator (manufactured by ESPEC Co., Ltd.), and the heat and pressure acceleration test was performed on the test piece.

Then, the test piece was taken out from the humid heat accelerator, and the lowermost first peeling film (the lowermost first peeling film in contact with the glass plate) and the film for forming a protective film adjacent to the first peeling film were removed. , the exposed adhesive layer is attached to the support plate through the double-sided adhesive tape, so that only the first peeling film of the lowermost layer and the layer adjacent to the first peeling film are removed from the aforementioned test piece after the heat and pressure acceleration test. The obtained test piece of the film for protective film formation was fixed to the said support plate.

Then, in the case of Examples 1 to 6, and Comparative Example 4, among the above-mentioned fixtures, the uppermost layer, the base material, the adhesive layer, and the protective film forming film that are farthest from the aforementioned support plate After removing the formed laminate, use a tensile tester to peel the exposed first peeling film from the adjacent coating at a peeling speed of 300mm/min and a peeling angle of 180°, and measure the peeling force at this time. In the case of Comparative Example 1 to Comparative Example 3, among the above fixed objects, the laminated object consisting of the base material, the adhesive layer and the film for forming the protective film on the uppermost layer farthest from the aforementioned support plate was removed, and a pulley was used to remove the Tensile testing machine, peel the exposed first peeling film from the adjacent substrate under the conditions of peeling speed of 300mm/min and peeling angle of 180°, and measure the peeling force at this time. The measured value of the peeling force of the 1st peeling film thus obtained was used as the index of the blocking resistance of the composite sheet for protective film formation.

Furthermore, when the peeling force of the first peeling film to be measured is sufficiently small, the aforementioned test piece is taken out from the humid heat accelerator, and the first peeling film (lowest When removing the film for forming a protective film adjacent to the first release film in contact with the glass plate in the lower layer, the first release film that exists as the measurement object of the release force is first released from the layer adjacent to the first release film (in Example 1). In the case of 1 to Example 6 and Comparative Example 4, it was the coating layer, and in the case of Comparative Example 1 to Comparative Example 3, it was the case where the substrate) was peeled off. In this case, take out the test piece from the humid heat accelerator, remove the lowermost first peeling film from the test piece, and then remove the film for forming a protective film adjacent to the first peeling film. The film for formation was bonded to the support plate via a double-sided adhesive tape, thereby fixing the test piece obtained by removing only the lowermost first peeling film from the test piece to the support plate, and for the fixed object, the same as above The peeling force of the first peeling film was measured.

The results are shown in Table 1.

[Surface roughness Ra of the outermost surface on the substrate side]

For the protective film-forming composite sheets of Examples 1 to 6 and Comparative Example 4 obtained above, the critical value λc was set to 0.8 using a contact surface roughness meter ("SURFTEST SV-3000" manufactured by Mitutoyo Co., Ltd.). mm, the evaluation length Ln was set to 4 mm, and the surface roughness Ra of the outermost surface on the substrate side, that is, the surface opposite to the substrate side in the coating layer was measured in accordance with JIS B0601:2001. The results are shown in Table 1. In Table 1, for the composite sheets for protective film formation of Comparative Examples 1 to 3, the surface roughness Ra of the surface opposite to the adhesive layer side of the above-mentioned substrate is described as the maximum surface roughness on the substrate side. The surface roughness Ra of the surface.

[gloss value of the surface of the coating]

For the protective film-forming composite sheets of Examples 1 to 6 and Comparative Example 4 obtained above, a gloss meter (a gloss meter "VG 2000" manufactured by Nippon Denshoku Co., Ltd.) was used to measure the self-coated composite sheet according to JIS K 7105. On the side opposite to the substrate side, the 20° specular gloss of the surface of the coating was measured, and the measured value was defined as the gloss value of the surface of the coating. The results are shown in Table 1.

[Measured value of haze from the coating side]

For the protective film-forming composite sheets of Examples 1 to 6 and Comparative Example 4 obtained above, a haze meter ("NDH-2000" manufactured by Nippon Denshoku Kogyo Co., Ltd.) was used to self-coat according to JIS K 7136. Haze was measured side by side. The results are shown in Table 1.

The composite sheets for protective film formation of Examples 1 to 6 were provided with a coating layer on the outermost layer on the base material side, and both laser printing property and blocking resistance were good.

In particular, the composite sheets for protective film formation in Examples 1, 2, 4, and 5 are superior in laser printing properties compared to the composite sheets for protective film formation in Examples 3 and 6. , presumably because, in the protective film-forming composite sheet of Example 1, Example 2, Example 4, and Example 5, "[thickness of coating layer (μm)]/[surface roughness of uneven surface of substrate Ra (μm)]" is larger, and the relative thickness of the coating relative to the surface roughness Ra of the concave-convex surface of the substrate is thicker, whereby the most surface on the substrate side (the side opposite to the substrate side in the coating The surface roughness Ra (μm) of the surface) is smaller.

In addition, the composite sheets for protective film formation in Examples 1 to 4 are superior in blocking resistance compared to the composite sheets for protective film formation in Examples 5 and 6. The coating layer thickness of the composite sheet for protective film formation of Example 4 was thin.

In addition, about the composite sheet for protective film formation of Example 1 - Example 6, the void part was not confirmed between the base material and the adhesive layer.

On the other hand, the composite sheet for protective film formation of Comparative Example 1 is the same as the composite sheet for protective film formation shown in FIG. The surface (surface) on the side of the agent layer is uneven and the surface (back surface) on the opposite side is also not provided with a coating layer. Therefore, although the blocking resistance is excellent, the laser printing property is poor.

The composite sheet for protective film formation of Comparative Example 2 is the same as the composite sheet for protective film formation shown in FIG. It has a smooth surface and does not have a coating, so although the laser printing property is good, the blocking resistance is poor. The protective film-forming composite sheet of Comparative Example 3 also had the same configuration as the protective film-forming composite sheet of Comparative Example 2, but not only had poor blocking resistance but also poor laser printing properties. The cause is presumed to be that the surface (surface) on the side having the adhesive layer in the base material is an uneven surface, and the surface roughness Ra of the uneven surface is larger than the surface roughness Ra of the protective film forming composite sheet of Comparative Example 2. It is speculated that in Comparative Example 3, since the surface roughness Ra of the above-mentioned concave-convex surface is large, the shape of the concave-convex surface is also reflected on the surface of the protective film. Larger and less laser-printable. Furthermore, it is speculated that the protective film forming composite sheets of Comparative Example 2 and Comparative Example 3 all have gaps between the uneven surface of the base material and the adhesive layer, but due to the difference in the uneven surface of Comparative Example 3 compared with Comparative Example 2 Since the surface roughness Ra is large, the voids become large, and therefore the diffuse reflection of light in Comparative Example 3 is larger than in Comparative Example 2, and the laser printing property is worse.

The composite sheet for protective film formation of Comparative Example 4 is the same as the composite sheet for protective film formation of Example 1, and the surface (back surface) opposite to the surface (front surface) of the substrate having the adhesive layer is uneven. surface, and also has a coating, resistant to Excellent adhesion, but poor laser printing. The reason is presumed to be that, in the composite sheet for forming a protective film in Comparative Example 4, the outermost surface on the base material side (the surface opposite to the base material side in the coating layer) is lower than the side having the adhesive layer in the base material. The surface roughness Ra (μm) is larger when the surface (surface) is opposite to the surface (back surface).

(industry availability)

The present invention can be used to manufacture semiconductor wafers and the like whose backside is protected by a protective film.

1‧‧‧Composite sheet for protective film formation

10‧‧‧Support sheet

10a‧‧‧The surface of the support sheet

10b‧‧‧The back of the support sheet

11‧‧‧Substrate

11a‧‧‧The surface of the substrate

11b‧‧‧The back of the substrate

12‧‧‧adhesive layer

12a‧‧‧The surface of the adhesive layer

13‧‧‧Film for protective film formation

13a‧‧‧The surface of the protective film forming film

14‧‧‧Coating

14a‧‧‧coated surface

14b‧‧‧coated backside

15‧‧‧Peeling film

15a‧‧‧The surface of the release film

Claims (8)

A composite sheet for forming a protective film, comprising a support sheet, a film for forming a protective film on one surface of the support sheet, and a surface of the support sheet opposite to the side provided with the film for forming a protective film With a coating; the surface roughness (Ra) of the surface of the coating on the side opposite to the side in contact with the aforementioned support sheet is smaller than the surface roughness (Ra) of the surface of the aforementioned coating on the aforementioned support sheet . The composite sheet for forming a protective film as described in Claim 1, wherein the composite sheet for forming a protective film is further provided with a release film on the film for forming a protective film, and the peeling force of the release film measured by the following method is: 10mN/50mm or less; the method of measuring the peeling force of the peeling film is to make the protective film forming composite sheet with a peeling film width of 50mm and a length of 100mm on the protective film forming film, with the aforementioned coatings all facing the same direction and the aforementioned Laminate a plurality of sheets so that the total thickness of the coating layer becomes 10 μm to 60 μm, thereby producing a laminate in which one outermost layer is a coating layer and the other outermost layer is a release film, and the aforementioned laminate is used for the formation of the aforementioned protective film. After a force of 980.665mN is applied in the lamination direction of the composite sheet, after standing at 40°C for 3 days, the peeling film closest to the outermost coating layer in the lamination direction is peeled at a peeling speed of 300mm/min and a peeling angle Under the condition of 180°, peel off from the adjacent coating, and measure the peeling force at this time. The composite sheet for forming a protective film according to claim 1 or 2, wherein The support sheet is formed by laminating the substrate and the adhesive; the composite sheet for forming the protective film is formed by sequentially laminating the coating, the substrate, the adhesive layer, and the film for forming the protective film. The composite sheet for forming a protective film according to claim 3, wherein the adhesive layer is an energy ray curable layer or a non-energy ray curable layer. The composite sheet for forming a protective film according to claim 1 or 2, wherein the film for forming a protective film is a thermosetting layer or an energy ray curable layer. The composite sheet for forming a protective film according to claim 3, wherein the film for forming a protective film is a thermosetting layer or an energy ray curable layer. The composite sheet for forming a protective film according to claim 4, wherein the film for forming a protective film is a thermosetting layer or an energy ray curable layer. The composite sheet for forming a protective film according to claim 1 or 2, wherein the surface roughness (Ra) of the surface of the coating layer opposite to the side in contact with the support sheet is 0.5 μm or less.

Images