TW201938725A - Composite sheet for forming protective film and method of manufacturing semiconductor chip having protective film - Google Patents

Abstract

A composite sheet for forming a protective film (1) of the present application includes a substrate (11), an adhesive layer (12), and a film for forming a heat-curable protective layer (13) in this order, wherein the storage elastic modulus at 70 DEG C (G' (70)) of the adhesive layer (12) is 0.16 MPa or less, and the storage elastic modulus at 23 DEG C (G' (23)) of the adhesive layer (12) is 0.10 MPa or more.

Description

Protective film forming composite sheet and method for manufacturing semiconductor wafer with protective film

The present invention relates to a method for manufacturing a protective film-forming composite sheet and a semiconductor wafer with a protective film.
This application claims priority based on Japanese Patent Application No. 2018-043566 filed in Japan on March 9, 2018, and the contents thereof are incorporated herein by reference.

In recent years, a semiconductor device has been manufactured by applying a so-called face-down packaging method. In the flip-chip method, a semiconductor wafer having electrodes such as bumps on a circuit surface is used, and the electrodes are bonded to a substrate. Therefore, the back surface of the semiconductor wafer opposite to the circuit surface may be exposed.

There is a case where a resin film containing an organic material is formed on the back surface of the exposed semiconductor wafer as a protective film, and is stored in a semiconductor device as a semiconductor wafer with a protective film.
The protective film is used to prevent cracks in the semiconductor wafer after the dicing step and packaging.

To form such a protective film, for example, a composite sheet for forming a protective film is used, and the composite sheet for forming a protective film is provided with a thin film for forming a protective film for forming a protective film on a support sheet having a base material. In the protective film forming composite sheet, a protective film can be formed by curing the thin film for protective film formation, and the supporting sheet can be used as a dicing sheet and can be formed by integrating the protective film forming film and the dicing sheet. (See Patent Document 1). In the method of manufacturing a semiconductor wafer using a composite sheet for forming a resin film, since the semiconductor wafer is attached together with a protective film-forming film and a dicing sheet, it can be reduced compared to the previous method of separately performing these methods. The number of steps can reduce costs. As a method of dividing a semiconductor wafer and a protective film together, a method of dicing a semiconductor wafer using a dicing blade is widely used.

In contrast, in recent years, various semiconductor wafer singulation methods without using a dicing blade have been performed. For example, it is known to form a modified layer inside a semiconductor wafer by irradiating laser light so as to focus on a focus set inside the semiconductor wafer. Secondly, the modified layer is formed and attached to the back surface. A method for obtaining a semiconductor wafer by expanding a semiconductor wafer with a resin film in the plane direction of the resin film together with the resin film, cutting the resin film, and singulating the semiconductor wafer at the modified layer portion. The expansion of the resin film in a planar direction at a normal temperature of 15 to 25 ° C may result in poor division of the resin film. In order to divide the semiconductor wafer and the resin film together well, for example, it has been studied at- Cold expansion was performed at a low temperature of 15 ° C.

The division method using cold expansion is different from the method using a dicing blade. In a semiconductor wafer, a cutting portion caused by the dicing blade is not accompanied, and a large number of semiconductor wafers can be obtained from the semiconductor wafer. advantage. A thin film adhesive is used as a material for wafer bonding of a semiconductor wafer to a circuit formation surface of a substrate. In the past, when the thin film adhesive was used, the above-mentioned division method mainly used the aforementioned resin film (see Patent Document 2). 3)

When the composite sheet for forming a resin film is cold-expanded in a planar direction, the semiconductor wafers are expanded and the semiconductor wafers can be picked up more easily. At this time, a deviation occurs between the resin film-forming film and the support sheet, so that the adhesion between the resin film-forming film and the support sheet is reduced and the suitability for picking up a semiconductor wafer is improved. It is also known that when picking up a semiconductor wafer in this manner, the cut resin web-forming film can be fixedly left on the back surface of the semiconductor wafer and peeled from the support sheet (see Patent Document 1).

Therefore, the above-mentioned resin film can be used as a protective film when a semiconductor wafer including a thin film for forming a thermosetting protective film or a protective film of a cured product thereof can be applied by the method of cold expansion as described above. The method of manufacturing a semiconductor wafer is very useful.
Prior art literature patent literature

[Patent Document 1] Japanese Patent Laid-Open No. 2016-027655
[Patent Document 2] Japanese Patent Laid-Open No. 2012-222002
[Patent Document 3] Japanese Patent Laid-Open No. 2017-183705

Problems to be solved by the invention

However, in the manufacture of semiconductor wafers, when the protective film-forming composite sheet capable of realizing pick-up suitability is cold-expanded in a planar direction, the semiconductor wafer gap is expanded and a deviation occurs between the protective film-forming film and the support sheet. The part is momentarily peeled off, and a trace is left on the boundary between the part where the peeling occurs and the part where the peeling does not occur (in this specification, there is a case called "floating trace"), and the design of the pattern is low. In addition, after the semiconductor wafer is divided, the wafer and the protective film are inspected for cracks and defects by visual inspection or infrared laser.

Therefore, an object of the present invention is to provide a composite sheet for forming a protective film, and a method for manufacturing a semiconductor wafer and a semiconductor device using the protective sheet. The composite sheet for forming a protective film is applied at a temperature lower than normal temperature. When the semiconductor film with a protective film is manufactured by using a method of dividing by cold expansion and using a thin film for forming a thermosetting protective film, the floating between the adhesive layer generated after the cold expansion and the film for forming a hardening protective film. Traces disappear and the semiconductor wafer with the protective film can be picked up well.
Means to solve the problem

In order to solve the above-mentioned problems, the present inventors and others have conducted intensive studies and found that in the composite sheet for forming a protective film, the storage elastic modulus (G '(70)) at 70 ° C is less than or equal to a predetermined value by using an adhesive layer. And the storage elastic modulus (G '(23)) at 23 ° C is a predetermined value or more, and a thermosetting film is used as a protective film forming film, although the adhesive layer and the thermosetting protection are protected after cold expansion. The film for film formation is partially peeled off and a floating mark is generated. However, by the subsequent thermal curing step, the elastic modulus of the adhesive layer is reduced and the adhesive layer and the protective film are re-closed, so that the floating mark can be made. It disappears, and the semiconductor wafer with the protective film can be picked up well, and the aforementioned object can be achieved.

That is, the present invention is as follows.
[1] A composite sheet for forming a protective film, comprising a substrate, an adhesive layer, and a film for forming a thermosetting protective film in this order. The storage elastic modulus of the adhesive layer at 70 ° C. (G '(70) ) Is 0.16 MPa or less, and the storage elastic modulus (G '(23)) at 23 ° C is 0.10 MPa or more.
[2] The composite sheet for forming a protective film according to the above [1], wherein the storage elastic modulus (G '(70)) of the adhesive layer at 70 ° C is 0.01 MPa or more.
[3] The composite sheet for forming a protective film according to the above [1] or [2], wherein the storage elastic modulus (G '(23)) of the adhesive layer at 23 ° C is 0.45 MPa or less.
[4] The composite sheet for forming a protective film according to the above [3], wherein the adhesive layer is non-energy-ray-curable or energy-ray-curable.
[5] The composite sheet for forming a protective film according to the above [3] or [4], wherein a thickness of the adhesive layer is 3 to 20 μm.

[6] A method for manufacturing a semiconductor wafer with a protective film, comprising the following steps:
A step of laminating a semiconductor wafer on the side of the thin film for forming a thermosetting protective film of the composite sheet for forming a protective film as described in any one of the items [1] to [5] above to form a laminate;
A step of irradiating laser light inside the semiconductor wafer to form a modified layer inside the semiconductor wafer;
The step of cold-expanding the laminated body at a temperature lower than normal temperature to divide the heat-cured semiconductor wafer and the thermosetting protective film into thin films;
The step of forming the thin film for forming a thermosetting protective film of the laminated body into a protective film.
Invention effect

According to the present invention, it is possible to provide a composite sheet for forming a protective film, and a method for manufacturing a semiconductor wafer and a semiconductor device using the protective film. The composite sheet for forming a protective film is applied for cold expansion due to a temperature lower than normal temperature. In the division method, when a semiconductor film with a protective film is manufactured using the thin film for forming a thermosetting protective film, the adhesive layer generated after cold expansion and the thin film for forming a thermosetting protective film can be made. The floating traces of the substrate do not remain, and the semiconductor wafer with the protective film can be picked up well.

Forms used to implement the invention

◎ Composite sheet for forming protective film The composite sheet for forming protective film of the present invention comprises a substrate, an adhesive layer, and a film for forming a thermosetting protective film in this order. The storage elastic modulus of the adhesive layer at 70 ° C ( G '(70)) is 0.16 MPa or less, and the storage elastic modulus (G' (23)) at 23 ° C is 0.10 MPa or more.

The adhesive layer of the protective film-forming composite sheet of the present invention has a storage elastic modulus (G '(70)) at 70 ° C of 0.16 MPa or less, preferably 0.15 MPa or less, and more preferably 0.10 MPa or less, Particularly preferred is 0.06 MPa or less. When the storage elastic modulus (G '(70)) is equal to or less than the aforementioned upper limit ，, partial peeling between the adhesive layer and the film for forming a thermosetting protective film generated after cold expansion at a temperature lower than normal temperature, Under the conditions of subsequent thermal hardening, it is easy to disappear due to the low elastic modulus of the adhesive layer, and it is possible to prevent the floating trace from remaining. The storage elastic modulus (G '(23)) of the adhesive layer at 23 ° C is 0.10 MPa or more, preferably 0.15 MPa or more, more preferably 0.20 MPa or more, and particularly preferably 0.25 MPa or more. When the storage elastic modulus (G '(23)) is equal to or more than the aforementioned lower limit, the semiconductor wafer with the protective film is not excessively adhered to the adhesive layer after the film for forming a thermosetting protective film is thermally cured. Moreover, the semiconductor wafer with a protective film can be picked up satisfactorily.

The composite sheet for forming a protective film of the present invention is designed to prevent the adhesive layer from overflowing from the ends during thermal curing. The storage elastic modulus (G '(70)) of the adhesive layer at 70 ° C is 0.01. MPa or more is preferable, and 0.02 MPa or more is particularly preferable.
That is, the storage elastic modulus (G '(70)) of the adhesive layer at 70 ° C is preferably 0.16 MPa or less, preferably 0.01 MPa or more and 0.16 MPa or less. It is preferably 0.01 MPa or more and 0.15 MPa or less, more preferably 0.01 MPa or more and 0.10 MPa or less, particularly preferably 0.01 MPa or more and 0.06 MPa or less, and most preferably 0.02 MPa or more and 0.06 MPa or less.
In addition, in order to ensure the adhesion between the adhesive layer of the protective film forming composite sheet and the thermosetting protective film forming film, it is possible to suppress the protection from being attached to the pickup target when the semiconductor wafer with the protective film is picked up. Film semiconductor wafer, which can prevent wafer scattering, and can pick up the target semiconductor wafer with a protective film with high selectivity. The storage elastic modulus (G '(23)) of the adhesive layer at 23 ° C is less than 1.0MPa. Preferably, 0.7 MPa or less is preferable, and 0.4 MPa or less is particularly preferable.
That is, the storage elastic modulus (G '(23)) of the adhesive layer at 23 ° C is 0.10 MPa or more, preferably 0.10 MPa or more and 1.0 MPa or less, and preferably 0.15 MPa or more and 0.7 MPa or less. 0.20 MPa to 0.4 MPa is more preferable, and 0.25 MPa to 0.4 MPa is particularly preferable.

In the present specification, the "thin film for forming a thermosetting protective film" means a thing before the thermosetting, and the "protective film" means a thing after curing the thin film for the thermosetting protective film.
In this specification, a case in which at least the aforementioned substrate and the aforementioned adhesive layer are laminated is referred to as a "support sheet".

Further, in this specification, even after the thermosetting protective film-forming film is thermally cured, as long as the laminated structure of the support sheet and the thermosetting protective film-forming film (in other words, the supporting sheet and the protective film) can be maintained, This laminated structure is called a "composite sheet for forming a protective film".

In this specification, the term "normal temperature" means a temperature that is not normally cooled or heated, that is, a normal temperature, and includes, for example, a temperature of 15 to 25 ° C.
The so-called "cold expansion" refers to applying a spreading force in a direction parallel to the surface of the semiconductor wafer at a temperature lower than normal temperature (for example, -20 to 10 ° C).
In this specification, "storage elastic modulus" refers to a laminated body of an adhesive layer having a thickness of 200 μm as a sample and a dynamic viscoelasticity measuring device in a tensile mode, a frequency of 11 Hz, a heating rate of 3 ° C./min, and a measurement temperature range. Radon measured under the conditions of -20 ° C to 150 ° C and a measurement interval of 1 ° C.

FIG. 1 is a cross-sectional view schematically showing an embodiment of a composite sheet for forming a protective film of the present invention.
The protective film-forming composite sheet 1 shown here includes a substrate 11, an adhesive layer 12, and a thermosetting protective film-forming film 13 in this order. The storage elastic modulus (G '(70)) of the adhesive layer 12 at 70 ° C is 0.16 MPa or less, and the storage elastic modulus (G' (23)) at 23 ° C is 0.10 MPa or more. The composite sheet 1 for forming a protective film is further provided with a release film 15 on the thin film 13 for forming a thermosetting protective film, and the release film 15 is removed during use of the composite sheet 1 for forming a protective film. The thin film 13 for forming a thermosetting protective film becomes a protective film by thermosetting.

In the protective film forming composite sheet 1, an adhesive layer 12 is laminated on the aforementioned surface 11 a of the substrate 11, and a thermosetting protective film forming film 13 is laminated on a part of the surface 12 a of the adhesive layer 12. Further, among the surface 12a of the adhesive layer 12, the exposed surface on which the film 13 for forming a thermosetting protective film is not laminated, and the surface 13a (upper and side surfaces) of the film 13 for forming a thermosetting protective film are formed. A release film 15 is laminated.

The support sheet of the composite sheet for forming a protective film is preferably transparent to laser light of laser printing, and can protect the film for forming a thermosetting protective film or the film after forming the film for forming a thermosetting protective film by heat curing. The film is irradiated with laser light and laser light from the side of the support sheet, and performs laser printing through the support sheet.

In the process of manufacturing a semiconductor wafer with a protective film, the supporting sheet is preferably transparent to laser light. The semiconductor wafer can be irradiated with laser light in the infrared region from the side of the supporting sheet (in the case of SD). In addition, a modified layer can be formed inside the semiconductor wafer via a support sheet.

In addition, by subjecting the composite film for forming a protective film with a semiconductor wafer to cold expansion (CE), the semiconductor wafer can be divided into individual pieces using the formation site of the modified layer of the semiconductor wafer as a starting point. . In this case, it is preferable that the support sheet is transmissive to laser light during infrared inspection and the film for forming a thermosetting protective film is colored, so that it can be easily checked whether the film or film for forming a thermosetting protective film can be reliably cut off. 2. Whether there is a defect in the semiconductor wafer, and laser light can pass through the support sheet during infrared inspection to easily check the state of the semiconductor wafer, and to suppress the decline in manufacturing efficiency of the semiconductor device. This makes it possible to easily check whether the thin film or the protective film for forming the thermosetting protective film can be reliably cut and the state, and to suppress a decrease in the manufacturing efficiency of the semiconductor device.

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 FIG. 2, the same elements as those in FIG. 1 are shown, and the same reference numerals as those in FIG. 1 are added and detailed descriptions thereof are omitted. The same applies to the drawings after FIG. 2.
The protective film-shaped composite sheet 2 shown here, the thermosetting protective film forming film 23 is laminated on the entire surface 12a of the adhesive layer 12, and the jig adhesive layer 16 is laminated on the thermosetting layer. A part of the surface 23a of the thin film 23 for forming a protective film, and the surface 23a of the thin film 23 for forming a thermosetting film, the exposed surface of the adhesive layer 16 for jigs and the adhesive layer 16 for jigs are not laminated. The release film 15 is laminated on the surface 16a (upper surface and side surface), and is the same as the composite film 1 for forming a protective film shown in FIG. 1 except for the above points.

The composite film 2 for forming a protective film shown in FIG. 2 is in a state where the release film 15 is removed and the back surface of the semiconductor wafer (not shown) is attached to the surface 23a of the film 23 for forming a thermosetting protective film. A jig such as a ring frame is attached to the upper surface 16a of the jig adhesive layer 16 and used.

The composite sheet for forming a protective film of the present invention is not limited by the objects shown in Figs. 1 and 2, and a part of the structure of the objects shown in Figs. It can be deleted, and other structures can be further added to those previously described.

The film for forming a thermosetting protective film is cured by heating and becomes a protective film. The protective film is used to protect a semiconductor wafer or a back surface of the semiconductor wafer (a surface opposite to an electrode formation surface). The thin film for forming a protective film is soft and can be easily attached to an object to be attached. For example, the tensile elastic modulus (also referred to as the Young's modulus) of the protective film-forming film is about 1 × 10 ⁶ to 1 × 10 ⁸ Pa at 23 ± 2 ° C.
In contrast, the tensile elastic modulus (also referred to as the Young's modulus) of the protective film obtained by heat curing is hardened at 23 ± 2 ° C. and is about 1 × 10 ⁸ to 5.4 × 10 ⁹ pa.
The tensile elastic modulus (also referred to as the Young's modulus) of the protective film-forming film or the protective film can be measured in accordance with JIS K7161: 1994.

In the method for manufacturing a semiconductor wafer with a protective film described later, the protective film-forming composite sheet of the present invention is attached to a semiconductor wafer and is used to prepare a supporting film and a thermosetting protective film-forming film in this order. And semiconductor wafers.
Hereinafter, each structure of the composite sheet for protective film formation of this invention is demonstrated in detail.

○ Substrate The aforementioned substrate is in the form of a sheet or film. As a constituent material, a polymer having excellent cold resistance selected at a loss of -15 ° C (tanδ) of 0.05 or more, and stored at 80 ° C A polymer having excellent heat resistance having an elastic modulus (G ') of 35.0 MPa or more is preferred. For example, as a polymer having excellent heat resistance, a polymer having a higher Tg is considered to be good, and as a polymer having excellent cold resistance, a polymer having a lower Tg is considered to be soft The polymer is good.
The loss front (tan δ) at -15 ° C can be determined using the same conditions as in the measurement of the storage elastic modulus.

As a constituent material of a base material that satisfies both cold resistance and heat resistance at a loss of -15 ° C (tanδ) of 0.05 or more and a storage elastic modulus (G ') of 80 ° C of 35.0 MPa or more, there may be mentioned A product obtained by adding a soft component such as a resin having a low Tg for imparting cold resistance to various heat-resistant resins; a product obtained by adding and modifying a rubber component for imparting cold resistance; and a product having heat resistance The resin layer and the resin layer having cold resistance are laminated to form two or three layers. As the heat-resistant resin, a storage elastic modulus (G ') at 80 ° C is preferably 35.0 MPa or more, and examples thereof include polypropylene (PP), polybutylene terephthalate (PBT), and the like. As the resin having cold resistance, it is only necessary that the loss direct connection (tanδ) at -15 ° C is 0.05 or more, and examples thereof include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene ( HDPE) and other polyethylene (PE).

In addition, as the resin that can be used as a base material of a resin having cold resistance, polyolefins other than polyethylene such as polybutene, polybutadiene, polymethylpentene, and norbornene resin can be mentioned ; Ethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene-norbornene copolymer, etc. (that is, using ethylene as a monomer Copolymers obtained from the polymer); vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers (that is, resins obtained by using vinyl chloride as a monomer); polystyrene; polycyclic olefins; polyterephthalene Ethylene formate, polyethylene naphthalate, polyethylene isophthalate, polyethylene-2,6-naphthalene dicarboxylate, fully aromatic with all structural units being aromatic cyclic groups Polyesters such as polyesters; copolymers of two or more of the foregoing polyesters; poly (meth) acrylates; polyurethanes; polyurethane acrylates; polyimide; polyimide; polycarbonate; fluororesin; polycondensation Aldehyde; Modified polyphenylene ether; Polyphenylene sulfide; Polyfluorene; Polyetherketone.

In the present specification, the term "(meth) acrylic acid" refers to a concept including both "acrylic acid" and "methacrylic acid". The same applies to terms similar to (meth) acrylic acid.

The resin constituting the substrate may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of these can be arbitrarily selected.

The thickness of the substrate is preferably 15 to 300 μm, preferably 50 to 200 μm, and more preferably 60 to 150 μm. When the thickness of the substrate is within this range, the flexibility of the aforementioned protective film-forming composite sheet and the adhesion to the semiconductor wafer or semiconductor wafer are further improved.
Here, the "substrate thickness" means the thickness of the entire substrate, for example, the thickness of the substrate composed of a plurality of layers, and the total thickness of all the layers constituting the substrate.

The substrate may be composed of one layer (single layer), or may be composed of a plurality of layers. When composed of a plurality of layers, the plurality of layers may be the same as or different from each other. The combination system of equal plural layers is not particularly limited.
When the substrate is composed of a plurality of layers, the total thickness of each layer may be set to the above-mentioned preferred substrate thickness.

The surface roughness Ra of the surface (surface) of the base material having the adhesive layer is preferably 0.001 to 0.1 μm, more preferably 0.005 to 0.08 μm, and particularly preferably 0.01 to 0.04 μm. When the surface roughness Ra of the substrate surface is equal to or smaller than the upper limit value, laser printing can be performed more clearly on the protective film.
The aforementioned surface roughness Ra of the substrate surface means a so-called arithmetic average roughness obtained in accordance with JIS B0601: 2001.
The surface roughness Ra of the substrate surface can be adjusted, for example, as a substrate forming condition, a surface treatment condition, and the like.

As a method of singulating a semiconductor wafer into semiconductor wafers, an example is to irradiate laser light in the infrared region and form a modified layer inside the semiconductor wafer in such a way that it is focused on the focus set inside the semiconductor wafer. A method of dividing a semiconductor wafer into individual pieces by applying force to the semiconductor wafer and using the formation site of the modified layer as a starting point.
When the surface roughness Ra of the substrate surface is, for example, 0.01 to 0.2 μm, a composite film for forming a protective film having such a substrate is suitable for forming a reforming layer inside the semiconductor wafer and singulating the semiconductor wafer. When using.

On the other hand, the surface roughness Ra of the substrate (the surface (front surface) having the adhesive layer) is opposite to the surface (back surface), in other words, the surface of the support sheet and the surface provided with the film for forming a thermosetting protective film The (surface) is the surface roughness Ra of the opposite surface (back surface), preferably 0.001 to 4 μm, more preferably 0.005 to 3.7 μm, more preferably 0.01 to 3.4 μm, and particularly 0.02 to 3.1 μm. good. Since the surface roughness Ra of the back surface of the substrate is equal to or less than the upper limit 値, it is possible to more easily reduce the surface roughness Ra of the surface on the side opposite to the support sheet, and to face the semiconductor wafer from the support sheet side. When the laser light (SD) in the infrared region is irradiated, the laser light in the infrared region can pass through the support sheet to form a modified layer inside the semiconductor wafer, and it is easier to perform laser printing on the protective film more clearly.
The aforementioned surface roughness Ra of the back surface of the substrate can be adjusted, for example, by the molding conditions, surface treatment conditions, and the like of the substrate.

The resin of the material of the base material may also be a crosslinked material.
In addition, the resin of the material of the base material may be a thin film obtained by extrusion molding of a thermoplastic resin, or may be an extended product, or may be a hardening resin. Means thinning and hardening and thinning.
The substrate may be a colored article or a printed article.

In terms of having excellent heat resistance and appropriate flexibility, having good cold expansion properties and good picking properties, the base material preferably contains polypropylene.
The base material containing polypropylene may be, for example, a base material consisting of a single layer or a plurality of layers made of polypropylene, or a base material having a plurality of layers formed by laminating a polypropylene layer and a resin layer other than polypropylene. .
The composite sheet for forming a protective film has heat resistance in the base material, and can effectively suppress the occurrence of warping of the supporting sheet even under conditions where the film for forming a thermosetting protective film is heat-hardened.

The base material is a material having a high degree of thickness accuracy, that is, a material that can suppress variations in thickness regardless of the location. Among the above-mentioned constituent materials, examples of materials that can be used to form such a substrate having a high thickness accuracy include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, and ethylene-acetic acid. Vinyl ester copolymers and the like.

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

The optical characteristics of the substrate need only satisfy the optical characteristics of the support sheet described above. That is, the substrate may be transparent or opaque, and may be colored according to the purpose, or other layers may be vapor-deposited.

The base material is used to improve the adhesion with other layers such as an adhesive layer provided thereon. The substrate may be subjected to a sandblasting treatment on the surface, a roughening treatment by a solvent treatment, a corona discharge treatment, or an electron beam irradiation. Oxidation treatment such as plasma treatment, plasma treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment, etc.
In addition, the substrate may be a surface treated with a primer.
In addition, when the base material is a laminate of an antistatic coating layer and a plurality of protective film-forming composite sheets for storage, it may be a material having a layer that prevents the base material from adhering to other sheets and the base material to the adsorption table. .

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

○ Adhesive layer The aforementioned adhesive layer is in the form of a sheet or film, and the physical properties of the contained adhesive are adjusted to a storage elastic modulus (G '(70)) at 70 ° C of 0.16 MPa or less, at 23 ° C. The storage elastic modulus (G '(23)) is 0.10 MPa or more.
Examples of the adhesive include acrylic resin, urethane resin, rubber resin, silicone resin, epoxy resin, polyvinyl ether, polycarbonate, and ester resin. The adhesive resin is preferably an acrylic resin.

In addition, in the present invention, the "adhesive resin" is a concept including both a resin having adhesive properties and a resin having adhesive properties. For example, not only a resin having adhesive properties but also a combination of additives Resins that exhibit adhesiveness with other components such as resins, and resins that exhibit adhesiveness with the presence of triggers such as heat or water.

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

The thickness of the adhesive layer is preferably 1 to 100 μm, more preferably 1 to 60 μm, more preferably 1 to 30 μm, and particularly preferably 3 to 20 μm.
Here, the "thickness of the adhesive layer" means the thickness of the entire adhesive layer, for example, the thickness of the adhesive layer composed of a plurality of layers means the total thickness of all the layers constituting the adhesive layer.

The optical characteristics of the adhesive layer need only satisfy the optical characteristics of the support sheet described above. That is, the adhesive layer may be transparent or opaque, and may be colored according to the purpose.

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

In the present invention, the "energy ray" means a substance having an energy molecule among electromagnetic waves or charged particle rays, and examples thereof include ultraviolet rays, radiation, and electron rays.
The ultraviolet rays can be irradiated by using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet source. The electron beam is a substance that can be generated by an electron beam accelerator or the like by irradiation.
In the present invention, "energy ray hardenability" means a property that is hardened by irradiating energy rays, and "non-energy ray hardenability" means a property that does not harden even when energy rays are irradiated.

＜ Adhesive composition ＞
As the adhesive layer, an adhesive composition can be used. For example, an adhesive layer can be formed in a target part by apply | coating an adhesive composition on the formation target surface of an adhesive layer, and drying it as needed. A more specific method for forming the adhesive layer will be described in detail later along with the method for forming other layers. In the adhesive composition, the content ratio of the components that do not vaporize at normal temperature is usually the same as the content ratio of the aforementioned components in the adhesive layer. In this specification, the term "normal temperature" is as described above.

The application of the adhesive composition may be performed using a known method, and examples thereof include an air blade coater, a blade coater, a rod coater, a gravure coater, and a roll coater. , Roll coater, curtain flow coater, die coater, blade coater, screen coater, winding bar coater, roll coater, etc. method.

The drying conditions of the adhesive composition are not particularly limited. When the adhesive composition contains a solvent to be described later, it is preferable to heat and dry it. At this time, for example, the temperature is 70 to 130 ° C. for 10 seconds to 5 minutes. Drying is preferred.

When the adhesive layer is energy ray-curable, as the energy ray-curable adhesive composition containing the energy ray-curable adhesive, that is, the energy ray-curable adhesive composition includes, for example, a non-energy-ray-curable adhesive resin (I -1a) (hereinafter referred to as "adhesive resin (I-1a)") and an adhesive composition (I-1) of an energy ray hardening compound; an energy ray containing an unsaturated group The curable adhesive resin (I-2a) is introduced into the side chain of the non-energy ray curable adhesive resin (I-1a) (hereinafter, it may be referred to as "adhesive resin (I-2a)"). An adhesive composition (I-2); and an adhesive composition (I-3) containing the aforementioned adhesive resin (I-2a) and an energy ray-curable compound.

＜ Adhesive composition (I-1) ＞
The said adhesive composition (I-1) is a non-energy-ray-curable adhesive resin (I-1a) and an energy-ray-curable compound as mentioned above.

[Adhesive resin (I-1a)]
The adhesive resin (I-1a) is preferably an acrylic resin.
Examples of the acrylic resin include an acrylic polymer having at least a structural unit derived from an alkyl (meth) acrylate.
The acrylic resin may have only one structural unit or two or more structural units. When the acrylic resin has two or more kinds of structural units, the combination and ratio of these can be arbitrarily selected.

Examples of the alkyl (meth) acrylate include those having 1 to 20 carbon atoms in the alkyl group constituting the alkyl ester, and the alkyl group is preferably linear or branched.
Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, N-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 (also known as lauryl (meth) acrylate), (formyl Tridecyl acrylate, tetradecyl (meth) acrylate (also known as myristyl (meth) acrylate), pentadecyl (meth) acrylate, cetyl (meth) acrylate ((methyl) ) Palmyl acrylate is also known as), Heptadecyl (meth) acrylate, Octadecyl (meth) acrylate (also known as (meth) acrylic stearate), Nineteen (meth) acrylate, Eicosyl (meth) acrylate and the like.

In order to improve the adhesive force of the adhesive layer, the acrylic polymer is preferably a structural unit having an alkyl (meth) acrylate having a carbon number of 4 or more derived from the alkyl group. Moreover, in terms of further improving the adhesive force of the adhesive layer, the carbon number of the aforementioned alkyl group is preferably 4-12, and more preferably 4-8. The alkyl (meth) acrylate having a carbon number of 4 or more is preferably an alkyl acrylate.

The acrylic polymer is preferably a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from an alkyl (meth) acrylate.
Examples of the functional group-containing monomer include the functional group which is a starting point of cross-linking by reacting with a cross-linking agent described later, or the functional group-containing monomer in a compound not containing an unsaturated group described later. An unsaturated group reacts to introduce an unsaturated group into a side chain of an acrylic polymer.

Examples of the functional group in the functional group-containing monomer include a hydroxyl group, a carboxyl group, an amine group, and an epoxy group.
That is, examples of the functional group-containing monomer include a hydroxyl-containing monomer, a carboxyl-containing monomer, an amine-containing monomer, and an epoxy-containing monomer.

Examples of the hydroxyl-containing monomer include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 3 (meth) acrylate. -Hydroxyalkyl (meth) acrylate, such as hydroxypropyl, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc .; vinyl alcohol And non- (meth) acrylic unsaturated alcohols such as allyl alcohols (also referred to as unsaturated alcohols without a (meth) acrylfluorenyl skeleton) and the like.

Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids (that is, monocarboxylic acids having ethylenically unsaturated bonds) such as (meth) acrylic acid and crotonic acid; fumaric acid, Ethylene unsaturated dicarboxylic acids such as itaconic acid, maleic acid, citraconic acid (ie, dicarboxylic acids having ethylenically unsaturated bonds); anhydrides of the aforementioned ethylenically unsaturated dicarboxylic acids; methyl Carboxyalkyl (meth) acrylate and the like such as 2-carboxyethyl acrylate and the like.

The functional group-containing monosystem is preferably a hydroxyl-containing monomer or a carboxyl-containing monomer, and more preferably a hydroxyl-containing monomer.

The functional group-containing monomer constituting the acrylic polymer may be only one type, or may be two or more types. When there are two or more kinds of functional group-containing monomers, the combination and ratio of these can be arbitrarily selected.

In the aforementioned acrylic polymer, the content of the structural unit derived from the functional group-containing monomer is preferably 1 to 35% by mass relative to the total amount of the structural unit (total mass), and more preferably 2 to 32% by mass. It is particularly good to be 3 to 30% by mass.

The acrylic polymer may include a structural unit derived from an alkyl (meth) acrylate and a structural unit derived from a functional group-containing monomer, and may further have a structural unit derived from another monomer.
The other single system is not particularly limited as long as it can be copolymerized with an alkyl (meth) acrylate or the like.
Examples of the other monomer include styrene, α-methylstyrene, vinyl toluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

The other monomers constituting the acrylic polymer may be only one kind, or two or more kinds. When there are two or more other monomers, the combination and ratio of these can be arbitrarily selected.

The acrylic polymer can be used as the non-energy-ray-curable adhesive resin (I-1a).
On the other hand, the functional group in the acrylic polymer is a product obtained by reacting an unsaturated group-containing compound having an energy ray polymerizable unsaturated group (energy ray polymerizable group), which can be used as the energy. Linear hardening adhesive resin (I-2a).

The adhesive resin (I-1a) contained in the adhesive composition (I-1) may be only one type, or may be two or more types. When there are two or more types of the adhesive resin (I-1a), the combination and ratio of these can be arbitrarily selected.

In the adhesive composition (I-1), the content of the adhesive resin (I-1a) is preferably 5 to 99% by mass relative to the total mass of the adhesive composition (I-1), and 10 to 95%. Mass% is preferred, and 15 to 90 mass% is particularly preferred.

[Energy ray hardening compound]
Examples of the energy ray-curable compound contained in the adhesive composition (I-1) include a monomer or oligomer having an energy ray polymerizable unsaturated group and capable of being cured by irradiating the energy ray.
Among the energy ray-curable compounds, examples of the monomer include trimethylolpropane tri (meth) acrylate, neopentaerythritol (meth) acrylate, and neopentaerythritol tetra (meth) acrylic acid. Poly (meth) esters such as esters, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol (meth) acrylate, etc. Acrylates; urethane (meth) acrylates; polyester (meth) acrylates; polyether (meth) acrylates; epoxy (meth) acrylates, and the like.
Among the energy ray curable compounds, examples of the oligomer include oligomers obtained by polymerizing the monomers exemplified above.
In view of the large molecular weight, which makes it difficult to reduce the storage elastic modulus of the adhesive layer, the energy ray hardening compound is oligomerized with urethane (meth) acrylate and urethane (meth) acrylate. Good thing.

The energy ray-curable compound contained in the adhesive composition (I-1) may be one kind, or two or more kinds. When the energy ray-curable compound is two or more kinds, the combination and ratio of these can be arbitrarily set. To choose.

In the adhesive composition (I-1), the content of the energy ray-curable compound is preferably 1 to 95% by mass, and 5 to 90% relative to the total mass of the adhesive composition (I-1). Mass% is preferred, and 10 to 85 mass% is particularly preferred.

[Crosslinking agent]
As the adhesive resin (I-1a), when the aforementioned acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from an alkyl (meth) acrylate is used, an adhesive combination is used. The substance (I-1) preferably further contains a crosslinking agent.

The crosslinking agent is, for example, a substance that reacts with the functional group to crosslink the adhesive resin (I-1a) with each other.
Examples of the crosslinking cleavage include isocyanate-based crosslinking agents (such as isocyanate-containing isocyanates) such as toluene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates. Group-based cross-linking agent); epoxy-based cross-linking agents such as ethylene glycol glycidyl ether (that is, a cross-linking agent having an epoxy-propyl group); hexa [1- (2-methyl) -acyl ring Propane] acrylpropane-based cross-linking agents such as triphosphatriazine (also referred to as cross-linking agents with acrylpropane-alkyl); metal clamp-based cross-linkers such as aluminum clamp compounds (ie A cross-linking agent having a metal clamp structure); an isocyanurate-based cross-linking agent (also referred to as a cross-linking agent having an iso-cyanuric acid skeleton), and the like.
The isocyanate-based cross-linking agent is preferably used as the cross-linking agent to improve the cohesive force of the adhesive and to improve the cohesiveness of the adhesive layer.

The crosslinking agent contained in the adhesive composition (I-1) may be one kind, or two or more kinds, and when two or more kinds of crosslinking agents are used, the combination and ratio of these can be arbitrarily selected.

In the aforementioned adhesive composition (I-1), the content of the cross-linking agent is preferably 0.01 to 50 parts by mass relative to 100 parts by mass of the content of the adhesive resin (I-1a), and 0.1 to 20 parts by mass is preferred. Good, especially 0.3 ~ 15 parts by mass.

[Photopolymerization initiator]
The adhesive composition (I-1) may further contain a photopolymerization initiator. The adhesive composition (I-1) containing a photopolymerization initiator sufficiently undergoes a curing reaction even when irradiated with a low energy energy beam such as ultraviolet rays.

Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, and benzoin Benzoin compounds such as methyl benzoate, benzoin dimethyl ketal; acetophenone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 2,2-dimethyl Acetophenone compounds such as oxy-1,2-diphenylethane-1-one; bis (2,4,6-trimethylbenzyl) phenylphosphine oxide, 2,4,6- Fluorenylphosphine oxide compounds such as trimethylbenzylidene diphenylphosphine oxide; thioether compounds such as benzylphenyl sulfide, tetramethylthiuram monosulfide; 1-hydroxycyclohexylphenyl ketone Α-keto alcohol compounds; azo compounds such as azobisisobutyronitrile; titanocene compounds such as titanocene; 9-oxysulfur (thioxanthone) Compounds; peroxide compounds; diketone compounds such as diethylhydrazone; benzil; dibenzyl; diphenyl ketone; 2,4-diethyl 9-oxosulfide ; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane; 2-chloroanthraquinone and the like.
In addition, as the photopolymerization initiator, for example, a quinone compound such as 1-chloroanthraquinone; a photosensitizer such as an amine can also be used.

The photopolymerization initiator contained in the adhesive composition (I-1) may be one type or two or more types. When the photopolymerization initiator is two or more types, the combination and ratio of these can be arbitrarily selected. To choose.

The content of the photopolymerization initiator in the adhesive composition (I-1) is 100 parts by mass with respect to the content of the aforementioned energy ray-curable compound, preferably 0.01 to 20 parts by mass, and 0.03 to 10 parts by mass Preferably, 0.05 to 5 parts by mass is particularly preferred.

[Other additives]
The adhesive composition (I-1) is within a range that does not impair the effects of the present invention, and may contain other additives that do not conform to any of the above-mentioned components.
Examples of the other additives include antistatic agents, antioxidants, softeners (plasticizers), fillers (also referred to as fillers), rust inhibitors, colorants (pigments, dyes, etc.), sensitizers, and adhesives. Conventional additives such as an imparting agent, a reaction delaying agent, and a crosslinking accelerator (also referred to as a catalyst).
In addition, the so-called reaction delaying agent suppresses the unintended crosslinking of the adhesive composition (I-1) during storage by the action of a catalyst mixed into the adhesive composition (I-1). Reactions. Examples of the reaction delaying agent include a compound that forms a clamp complex by a clamp to a catalyst, and more specifically, a compound having two or more carbonyl groups (-C in one molecule) (= O)-).

The other additives contained in the adhesive composition (I-1) may be only one kind, or may be two or more kinds. When the other additives are two or more, the combination and ratio of these can be arbitrarily selected.

The content of the other additives in the adhesive composition (I-1) is not particularly limited, and may be appropriately selected depending on the type thereof.

[Solvent]
The adhesive composition (I-1) may contain a solvent. The adhesive composition (I-1) improves the coating suitability to the surface to be coated by containing a solvent.

The solvent is preferably an organic solvent. Examples of the organic solvent include ketones such as methyl ethyl ketone and acetone; esters such as ethyl acetate (that is, carboxylic acid esters); tetrahydrofuran and dioxane. Ethers; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; alcohols such as 1-propanol and 2-propanol.

As the solvent, for example, a solvent used in the production of the adhesive resin (I-1a) may be used in the adhesive composition (I- 1) In the production of the adhesive composition (I-1), a solvent that is the same as or different from the solvent used in the production of the adhesive resin (I-1a) may be added.

The solvent contained in the adhesive composition (I-1) may be one kind, or two or more kinds may be used. When there are two or more solvents, the combination and ratio of these can be arbitrarily selected.

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

＜ Adhesive composition (I-2) ＞
The adhesive composition (I-2) is, as described above, an energy-ray-curable adhesive resin (I) containing an unsaturated group introduced into a side chain of the non-energy-ray-curable adhesive resin (I-1a). -2a).

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

The unsaturated group-containing compound, in addition to the energy ray polymerizable unsaturated group, is capable of reacting with the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a). Bonded base compound.
Examples of the energy ray polymerizable unsaturated group include a (meth) acrylfluorenyl group, a vinyl group (also referred to as an ethenyl group), an allyl group (also referred to as a 2-propenyl group), and the like (a Preferably, it is acryl).
Examples of the group capable of bonding with a functional group in the adhesive resin (I-1a) include an isocyanate group and an epoxy group capable of bonding to a hydroxyl group or an amino group, and a group capable of bonding to a carboxyl group or an epoxy group. Bonded hydroxyl and amine groups.

Examples of the unsaturated group-containing compound include (meth) acrylic acid isocyanate, (meth) acrylic acid isocyanate, and propylene oxide (meth) acrylate.

The adhesive resin (I-2a) contained in the adhesive composition (I-2) may be only one kind, or two or more kinds. When there are two or more types of the adhesive resin (I-2a), the combination and ratio of these can be arbitrarily selected.

In the adhesive composition (I-2), the content of the adhesive resin (I-2a) is preferably 5 to 99% by mass relative to the total mass of the adhesive composition (I-2), and 10 to 95%. Mass% is preferred, and 10 to 90 mass% is particularly preferred.

[Crosslinking agent]
As the adhesive resin (I-2a), for example, similar to the adhesive resin (I-1a), when the aforementioned acrylic polymer having a structural unit derived from a functional group-containing monomer is used, an adhesive combination is used. (I-2) may further contain a crosslinking agent.

Examples of the crosslinking agent in the adhesive composition (I-2) include the same as the crosslinking agent in the adhesive composition (I-1).
The crosslinking agent contained in the adhesive composition (I-2) may be one kind, or two or more kinds. When there are two or more kinds of crosslinking agents, the combination and ratio of these can be arbitrarily selected.

In the aforementioned adhesive composition (I-2), the content of the adhesive resin (I-2a) is equivalent to 100 parts by mass, and the content of the cross-linking agent is preferably 0.01 to 50 parts by mass, and 0.1 to 20 parts by mass as Preferably, 0.3 to 15 parts by mass is particularly preferred.

[Photopolymerization initiator]
The adhesive composition (I-2) may further contain a photopolymerization initiator. The adhesive composition (I-2) containing a photopolymerization initiator is a hardening reaction that fully progresses even if it irradiates a low energy energy ray such as ultraviolet rays.

Examples of the photopolymerization initiator in the adhesive composition (I-2) include the same as the photopolymerization initiator in the adhesive composition (I-1).
The photopolymerization initiator contained in the adhesive composition (I-2) may be only one type, and may also be two or more types. When there are two or more photopolymerization initiators, the combination and ratio of these can be arbitrarily selected.

In the adhesive composition (I-2), the content of the adhesive resin (I-2a) is equivalent to 100 parts by mass. The content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass, and 0.03 to 10 parts by mass. Preferably, 0.05 to 5 parts by mass is particularly preferred.

[Other additives]
The pressure-sensitive adhesive composition (I-2) is within a range that does not impair the effects of the present invention, and may contain other additives that do not meet any of the above-mentioned components.
Examples of the other additives in the adhesive composition (I-2) include the same as the other additives in the adhesive composition (I-1).
The other additives contained in the adhesive composition (I-2) may be only one kind, or may be two or more kinds. When there are two or more other additives, the combination and ratio of these can be arbitrarily selected.

The content of the other additives in the adhesive composition (I-2) is not particularly limited, and may be appropriately selected depending on the type thereof.

[Solvent]
The adhesive composition (I-2) may contain a solvent for the same purpose as in the case of the adhesive composition (I-1).
Examples of the solvent in the adhesive composition (I-2) include the same solvents as those in the adhesive composition (I-1).
The solvent contained in the adhesive composition (I-2) may be one kind or two or more kinds. When the solvent is two or more kinds, the combination and ratio of these can be arbitrarily selected.
The content of the solvent in the adhesive composition (I-2) is not particularly limited, and it may be adjusted appropriately.

＜ Adhesive composition (I-3) ＞
The adhesive composition (I-3) is as described above, and contains the adhesive resin (I-2a) and an energy ray-curable compound.

In the adhesive composition (I-3), the content of the adhesive resin (I-2a) is preferably 5 to 99% by mass relative to the total mass of the adhesive composition (I-3), and 10 to 95%. Mass% is preferred, and 15 to 90 mass% is particularly preferred.

[Energy ray hardening compound]
Examples of the energy ray-curable compound contained in the adhesive composition (I-3) include monomers and oligomers that have an energy ray polymerizable unsaturated group and can be hardened by irradiating energy rays; The same thing as the energy-ray-curable compound contained in the adhesive composition (I-1) is mentioned.
The energy ray-curable compound contained in the adhesive composition (I-3) may be one kind, or two or more kinds. When the energy ray-curable compound is two or more kinds, the combination and ratio of these may be Choose arbitrarily.

The content of the adhesive composition (I-3) is equivalent to 100 parts by mass of the adhesive resin (I-2a), and the content of the energy ray-curable compound is preferably 0.01 to 300 parts by mass, and 0.03 to 200. Part by mass is preferred, and 0.05 to 100 parts by mass is particularly preferred.

[Photopolymerization initiator]
The adhesive composition (I-3) may further contain a photopolymerization initiator. The adhesive composition (I-3) containing a photopolymerization initiator sufficiently undergoes a hardening reaction even when irradiated with low energy energy rays such as ultraviolet rays.

Examples of the photopolymerization initiator in the adhesive composition (I-3) include the same as the photopolymerization initiator in the adhesive composition (I-1).
The photopolymerization initiator contained in the adhesive composition (I-3) may be one kind or two or more kinds. When the photopolymerization starter is two or more kinds, the combination and ratio of these can be arbitrarily selected. select.

In the adhesive composition (I-3), the content of the photopolymerization initiator is 0.01 to 20 parts by mass based on 100 parts by mass of the total content of the adhesive resin (I-2a) and the energy ray-curable compound. Preferably, 0.03 to 10 parts by mass is preferred, and 0.05 to 5 parts by mass is particularly preferred.

[Other additives]
The adhesive composition (I-3) is within a range that does not impair the effects of the present invention, and may contain other additives that do not conform to any of the above-mentioned components.
Examples of the other additives include the same as the other additives in the adhesive composition (I-1).
The other additives contained in the adhesive composition (I-3) may be only one kind, or may be two or more kinds. When there are two or more other additives, the combination and ratio of these can be arbitrarily selected.

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

[Solvent]
The adhesive composition (I-3) is for the same purpose as in the case of the adhesive composition (I-1), and may contain a solvent.
Examples of the solvent in the adhesive composition (I-3) include the same solvents as those in the adhesive composition (I-1).
The solvent contained in the adhesive composition (I-3) may be only one kind, or two or more kinds may be used. When there are two or more solvents, the combination and ratio of these can be arbitrarily selected.
The content of the solvent in the adhesive composition (I-3) is not particularly limited, and it may be adjusted appropriately.

<Adhesive composition other than adhesive composition (I-1) to (I-3)>
So far, the adhesive composition (I-1), the adhesive composition (I-2), and the adhesive composition (I-3) have mainly been explained in terms of the way in which the components are contained. All adhesive compositions other than these three adhesive compositions (in this specification, they are referred to as "adhesive compositions other than adhesive compositions (I-1) to (I-3)"). Can be used in the same way.

Examples of the adhesive composition other than the adhesive compositions (I-1) to (I-3) include non-energy ray curable adhesive compositions in addition to energy ray curable adhesive compositions.
Examples of the non-energy-ray-curable adhesive composition include acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyvinyl ethers, and polycarbonates. The adhesive composition (I-4) containing a non-energy-ray-curable adhesive resin (I-1a) such as an ester-based resin is preferably an acrylic resin.

The adhesive composition other than the adhesive composition (I-1) to (I-3) is preferably one or two or more kinds of cross-linking agents, and the content can be set to the same as the above-mentioned adhesive composition. (I-1) Isochronous.

＜ Adhesive composition (I-4) ＞
As a preferable thing in an adhesive composition (I-4), the thing containing the said adhesive resin (I-1a) and a crosslinking agent is mentioned, for example.

[Adhesive resin (I-1a)]
Examples of the adhesive resin (I-1a) in the adhesive composition (I-4) include the same as the adhesive resin (I-1a) in the adhesive composition (I-1).
The adhesive resin (I-1a) contained in the adhesive composition (I-4) may be one type or two or more types, and when the adhesive resin (I-1a) is two or more types, such The combination and ratio can be arbitrarily selected.

In the adhesive composition (I-4), the content of the adhesive resin (I-1a) is preferably 5 to 99% by mass relative to the total mass of the adhesive composition (I-4), and 10 to 95%. Mass% is preferred, and 15 to 90 mass% is particularly preferred.

[Crosslinking agent]
As the adhesive resin (I-1a), when the aforementioned acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from an alkyl (meth) acrylate is used, an adhesive combination is used. The substance (I-4) preferably contains a crosslinking agent.

Examples of the crosslinking agent in the adhesive composition (I-4) include the same as the crosslinking agent in the adhesive composition (I-1).
There may be only one type of crosslinking agent contained in the adhesive composition (I-4), and two or more types may be sufficient. When there are two or more kinds of crosslinking agents, the combination and ratio of these can be arbitrarily selected.

In the aforementioned adhesive composition (I-4), the content of the cross-linking agent is preferably 0.01 to 50 parts by mass, and 0.1 to 20 parts by mass with respect to 100 parts by mass of the content of the adhesive resin (I-1a). Preferably, 0.3 to 15 parts by mass is particularly preferred.

[Other additives]
The adhesive composition (I-4) is within a range that does not impair the effect of the present invention, and may contain other additives that do not conform to any of the above-mentioned components.
Examples of the other additives include the same as the other additives in the adhesive composition (I-1).
The other additives contained in the adhesive composition (I-4) may be only one kind, or may be two or more kinds. When there are two or more other additives, the combination and ratio of these can be arbitrarily selected.

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

[Solvent]
The adhesive composition (I-4) may contain a solvent for the same purpose as in the case of the adhesive composition (I-1).
Examples of the solvent in the adhesive composition (I-4) include the same solvents as those in the adhesive composition (I-1).
The solvent contained in the adhesive composition (I-4) may be only one kind, or two or more kinds may be used. When there are two or more solvents, the combination and ratio of these can be arbitrarily selected.
The content of the solvent in the adhesive composition (I-4) is not particularly limited, and it may be adjusted appropriately.

<Manufacturing method of an adhesive composition>
Adhesive compositions other than the adhesive composition (I-1) to (I-3) and the adhesive composition (I-1) such as the adhesive composition (I-4), It can be obtained by compounding each component which comprises the said adhesive agent, the component other than the said adhesive agent, etc. which are necessary to comprise an adhesive composition.
The order in which the components are added is not particularly limited, and two or more components may be added simultaneously.
When a solvent is used, the solvent may be mixed with any formulation component other than the solvent, and the formulation component may be diluted and used beforehand, or any formulation component other than the solvent may be prepared without dilution, and the solvent may be blended with these formulations. The ingredients are mixed and used.
The method of mixing the ingredients at the time of preparation is not particularly limited, and conventional methods such as a method of mixing using a stirrer or a stirring blade, a method of mixing using a mixer, and a method of mixing by applying an ultrasonic wave are appropriately used. Just select it.
The temperature and time during the addition and mixing of the components are not particularly limited as long as the prepared components do not deteriorate, and may be appropriately adjusted. The temperature is preferably 15 to 30 ° C.

○ Support Sheet The support sheet is a product obtained by laminating a substrate and the adhesive layer, and is equivalent to a task such as a dicing sheet that can protect the surface of a film for forming a protective film in a cutting step or the like.

The thickness of the support sheet may be appropriately selected according to the purpose, and is based on the fact that sufficient flexibility can be imparted to the composite sheet for forming a protective film, adhesion to a semiconductor wafer, and operability during production of the composite sheet for forming a protective film. In the case, it is preferably 10 to 500 μm, preferably 20 to 350 μm, and particularly preferably 30 to 200 μm.
Here, the "thickness of the support sheet" means the total of the thickness of the base material and the thickness of the adhesive layer.
In addition, the support sheet can be an uneven surface on at least one surface. When the support sheet is included in the convex part of the uneven surface, the thickness of the support sheet can be calculated by setting the tips of the convex parts together. .
In addition, in this specification, "thickness" can be calculated | required by selecting thickness at arbitrary 5 places, for example, using a constant-pressure thickness measuring device, and calculating the average of a measurement gall.

For the reasons described above, the support sheet is preferably transparent. However, as long as it is in a range that can ensure the transmittance of a predetermined laser wavelength and the checkability that can be cut off, it may be opaque or colored according to the purpose.

Specifically, the transmittance of light with a wavelength of 532 nm on the support sheet is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. When the light transmittance is in this range, laser light can be irradiated to the thermosetting protective film-forming film or the protective film through the support sheet, and the printing can be performed more clearly when such printing is performed.
On the other hand, the upper limit of the transmittance of light having a wavelength of 532 nm in the support sheet is not particularly limited, and it can be set to 95%, for example.
That is, the transmittance of light with a wavelength of 532 nm on the support sheet is preferably 30% or more and 95% or less, more preferably 50% or more and 95% or less, and particularly preferably 70% or more and 95% or less.

In addition, the transmittance of light having a wavelength of 1064 nm on the supporting sheet is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. Similarly, the transmittance of light with a wavelength of 1342 nm on the support sheet is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. With the aforementioned light transmittance in such a range, when the semiconductor wafer is irradiated with laser light (SD) in the infrared region from the side of the support sheet, the laser light in the infrared region can pass through the support sheet and satisfactorily inside the semiconductor wafer. The modified layer is formed, and the thermosetting protective film-forming film or the protective film is irradiated with laser light through the support sheet, and during such printing, the characters can be printed more clearly.
On the other hand, the upper limit of the transmittance of the support sheet with a wavelength of 1064 nm is not particularly limited, and it can be set to 95%, for example. Similarly, the upper limit of the transmittance of light having a wavelength of 1342 nm in the support sheet is not particularly limited, and it can be set to 95%, for example.
That is, the transmittance of light having a wavelength of 1064 nm on the support sheet is preferably 30% or more and 95% or less, more preferably 50% or more and 95% or less, and particularly preferably 70% or more and 95% or less. Similarly, the transmittance of light with a wavelength of 1342 nm on the supporting sheet is preferably 30% or more and 95% or less, more preferably 50% or more and 95% or less, and particularly preferably 70% or more and 95% or less.

○ Film for forming thermosetting protective film The film for forming thermosetting protective film is thermosetting, and after heat curing, it finally becomes a protective film with high impact resistance. This protective film prevents, for example, cracking of the semiconductor wafer after the dicing step.
The thin film for protective film formation can be formed from the composition for thermosetting protective film formation mentioned later.

The film for forming a thermosetting protective film may be a single layer (single layer) or a plurality of layers. When the film for forming a thermosetting protective film is a plurality of layers, the plural layers may be the same as or different from each other. In addition, the combination of the plural layers is not particularly limited.

The thickness of the film for forming a thermosetting protective film is not particularly limited, but is preferably 1 to 100 μm, more preferably 5 to 75 μm, and particularly preferably 5 to 50 μm. When the thickness of the thin film for forming a thermosetting protective film is not less than the aforementioned lower limit, the adhesion force to the semiconductor wafer and the semiconductor wafer to be adhered becomes large. In addition, since the thickness of the film for forming a thermosetting protective film is equal to or less than the aforementioned upper limit ，, it is possible to more easily cut the protective film of the cured product by using a shear force during cold expansion.

As a preferable film for thermosetting protective film formation, the thing containing a polymer component (A) and a thermosetting component (B) is mentioned, for example. The polymer component (A) is a component which can be considered as a polymerized compound formed by a polymerization reaction. The thermosetting component (B) is a component capable of curing (polymerizing) a reaction using heat as a trigger for the reaction. The polymerization reaction of the present invention also includes a polycondensation reaction. Hereinafter, the “film for forming a thermosetting protective film” is also simply referred to as a “film for forming a protective film”.

In the present invention, the adhesive force between the protective film and the adhesive layer obtained by curing the protective film-forming film is preferably 50 to 1500 mN / 25 mm, more preferably 52 to 1450 mN / 25 mm, and 53 to 1430 mN / 25mm is particularly good. When the adhesive force is equal to or more than the lower limit 値, when a semiconductor wafer with a protective film is picked up, the semiconductor wafer with a protective film other than the target can be picked up and the semiconductor wafer with a protective film can be picked up with high selectivity. In addition, when the adhesive force is equal to or less than the upper limit 値, when a semiconductor wafer with a protective film is picked up, cracks and defects in the semiconductor wafer can be suppressed. In this way, with the aforementioned adhesive force being within a specific range, the composite sheet system for forming a protective film has good pickup suitability.

The adhesive force between a protective film and an adhesive layer can be measured using the following method.
That is, a protective film-forming composite sheet having a width of 25 mm and an arbitrary length is attached to the adherend by the protective film-forming film.
Next, the protective film-forming film is thermally cured to form a protective film, and then the support sheet is peeled from the protective film attached to the adherend at a peeling speed of 300 mm / min. The peeling at this time is a so-called 180 in which the supporting sheet is peeled in the longitudinal direction (the longitudinal direction of the protective sheet-forming composite sheet) so that the angle between the protective film and the supporting sheet contacting each other is 180 °. ∘ Peel. Then, the load (peeling force) at the time of peeling at 180∘ was measured, and the measured 値 was used as the aforementioned adhesive force (mN / 25mm).

The length of the composite sheet for forming a protective film to be measured is not particularly limited as long as it can stably detect the adhesive force, and it is preferably 100 to 300 mm. The measurement is performed in a state where the adherend is attached to the protective film-forming composite sheet, and it is preferable to stabilize the attached state of the protective film-forming composite sheet in advance.

In the present invention, the adhesive force between the protective film-forming film and the support sheet is not particularly limited. For example, it may be 80 mN / 25 mm or more, preferably 100 mN / 25 mm or more, and more preferably 150 mN / 25 mm or more. Particularly preferred is 200mN / 25mm or more. With the aforementioned adhesive force of 100 mN / 25 mm or more, peeling of the protective film-forming film from the support sheet during dicing can be suppressed, and for example, scattering of a semiconductor wafer including the protective film-forming film on the back surface from the support sheet can be suppressed.

On the other hand, the upper limit of the adhesive force between the protective film-forming film and the support sheet is not particularly limited, and may be any of 4000 mN / 25 mm, 3000 mN / 25 mm, 2000 mN / 25 mm, and the like.
That is, the adhesion between the protective film-forming film and the support sheet is preferably 80 to 4000 mN / 25 mm, more preferably 100 to 4000 mN / 25 mm, more preferably 150 to 3000 mN / 25 mm, and 200 to 2000 mN. / 25mm is particularly good.

The adhesive force between the protective film-forming film and the adhesive layer is the same as the adhesive force between the protective film and the support sheet except that the protective film-forming film provided for measurement is not cured by heating. Method.

The adhesive force between the protective film and the adhesive layer, and the adhesive force between the protective film-forming film and the adhesive layer can be adjusted, for example, by the type and amount of the components contained in the protective film-forming film and the amount of the adhesive. The material of the layer, the surface state of the adhesive layer, and the like can be appropriately adjusted.

For example, the type and amount of the component contained in the protective film-forming film can be adjusted by the type and amount of the component contained in the protective film-forming composition described later. In addition, the type and content of the polymer (b), the content of the filler (d), or the content of the cross-linking agent (f) can be adjusted by adjusting the content and content of the polymer (b) among the components contained in the composition for forming a protective film. The adhesive force between the protective film or the film for forming a protective film and the support sheet can be easily adjusted.

In addition, for example, when the layer on which the protective film-forming film is provided on the support sheet is an adhesive layer, the constituent material thereof can be appropriately adjusted by adjusting the type and amount of the components contained in the adhesive layer. The types and amounts of the components contained in the adhesive layer can be adjusted by the types and amounts of the components contained in the above-mentioned adhesive composition.
On the other hand, when the layer on which the protective film-forming film is provided on the support sheet is used as the base material, the adhesive force between the protective film or the protective film-forming film and the support sheet can be adjusted in addition to the constituent material of the substrate Wood surface state. In addition, the surface state of the substrate can be subjected to, for example, surface treatments for improving the adhesion between the substrate and other layers and the aforementioned surface treatments, that is, roughening treatments such as sandblasting, solvent treatment, etc .; Oxidation treatments such as halo discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment, etc .; and primer treatment are adjusted.

The thin film for forming a protective film may be thermosetting and energy ray-curable, and may be, for example, a substance containing an energy ray-curable component (a).
The energy ray-curable component (a) is preferably uncured, preferably has adhesiveness, and is preferably uncured and has adhesiveness.

The protective film forming film may be a single layer (single layer) or a plurality of layers. When the protective film forming film is a plurality of layers, the plurality of layers may be the same as or different from each other. The combination system is not particularly limited.

The thickness of the protective film-forming film is preferably 1 to 100 μm, more preferably 5 to 75 μm, and particularly preferably 5 to 50 μm. When the thickness of the thin film for forming a protective film is not less than the aforementioned lower limit, a protective film having a high protective ability can be formed. In addition, when the thickness of the protective film-forming film is equal to or less than the aforementioned upper limit 値, an excessive thickness can be suppressed.
Here, the "thickness of the thin film for forming a protective film" means the thickness of the entire thin film for forming a protective film. For example, the thickness of the thin film for forming a protective film composed of a plurality of layers means forming a protective film. The total thickness of all layers of the film is used.

The curing conditions for curing the thin film for forming a protective film to form a protective film are not particularly limited as long as the degree of hardening of the protective film sufficiently performs its function, and may be appropriately selected according to the type of the thin film for forming a protective film .
For example, the heating temperature when the film for forming a thermosetting protective film is cured is preferably 100 ° C or higher and 200 ° C or lower, 110 ° C or higher and 180 ° C or lower, or 120 ° C or 170 ° C or lower. In addition, the heating time during the hardening is preferably 0.5 hours to 5 hours, more preferably 0.5 hours to 3 hours, and 1 hour to 2 hours.

＜ Composition for forming thermosetting protective film ＞＞
The thin film for forming a thermosetting protective film can be formed of a composition for forming a thermosetting protective film containing its constituent material. For example, the film for forming a thermosetting protective film can be formed on a target by applying the composition for forming a thermosetting protective film to the formation target surface of the film for forming a thermosetting protective film and drying it as necessary. Parts. The content ratio of the components which are not vaporized at room temperature in the composition for forming a thermosetting protective film is usually the same as the content ratio of the components in the film for forming a thermosetting protective film. Here, the so-called "normal temperature" is as described above.

The application of the composition for forming a thermosetting protective film can be performed using, for example, the same method as in the case of applying the above-mentioned adhesive composition.

The drying conditions of the composition for forming a thermosetting protective film are not particularly limited. When the composition for forming a thermosetting protective film contains a solvent to be described later, it is preferable to dry by heating. In this case, for example, the temperature is 70 ° C to 130 ° C. And it is better to dry it under the condition of 10 seconds to 5 minutes.

<Protective film forming composition (III-1)>
Examples of the composition for forming a thermosetting protective film include a composition (III-1) for forming a thermosetting protective film containing a polymer component (A) and a thermosetting component (B) (in this specification , "The protective film-forming composition (III-1)" may be referred to as the case).

[Polymer component (A)]
The polymer component (A) is a polymer compound for imparting film-forming properties and handleability to a film for forming a thermosetting protective film.
The composition (III-1) for forming a protective film and the polymer component (A) contained in the film for forming a thermosetting protective film may be only one kind, or two or more kinds. When the polymer component (A) is two or more kinds, the combination and ratio of these can be arbitrarily selected.

Examples of the polymer component (A) include an acrylic resin (for example, a resin having a (meth) acryl group), a polyester, a urethane resin (for example, a resin having a urethane bond), Acrylic urethane resin, polysiloxane resin (for example, a resin having a siloxane bond), rubber resin (for example, a resin having a rubber structure), a phenoxy resin, a thermosetting polyimide, etc. An acrylic resin is preferred.

Examples of the acrylic resin in the polymer component (A) include conventional acrylic polymers.
The weight average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000. When the weight average molecular weight of the acrylic resin is at least the aforementioned lower limit 値, the shape stability (time-dependent stability during storage) of the film for forming a thermosetting protective film is improved. In addition, since the weight average molecular weight of the acrylic resin is equal to or less than the aforementioned upper limit ，, the film for forming a thermosetting protective film can easily follow the uneven surface of the adherend and can further suppress the formation of the film for forming the adherend and the thermosetting protective film. Gap and the like.
In addition, in this specification, "weight average molecular weight" means polystyrene conversion 値 measured using a gel permeation chromatography (GPC) method unless it is notified in advance.

The glass transition temperature (Tg) of the acrylic resin is preferably -60 to 70 ° C, and more preferably -30 to 50 ° C. When the Tg of the acrylic resin is at least the aforementioned lower limit 値, it is possible to suppress the adhesion between the protective film and the support sheet and to improve the peelability of the support sheet. In addition, when the Tg of the acrylic resin is equal to or less than the aforementioned upper limit 値, the adhesion between the film for forming a thermosetting protective film and the protective film and the adherend is improved.
In this specification, the "glass transition temperature (Tg)" means the DSC curve of a sample measured using a differential scanning calorimeter, and it is represented by the temperature of the inflection point of the obtained DSC curve.

Examples of the acrylic resin include one or more (meth) acrylic acid ester polymers; selected from (meth) acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-hydroxyl A copolymer of two or more kinds of monomers such as methacrylamide.

Examples of the (meth) acrylate constituting the acrylic resin 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, undecy (meth) acrylate, (meth) acrylic acid dodecanoic acid (also known as lauryl (meth) acrylate), (methyl Tridecyl acrylate, tetradecyl (meth) acrylate (also known as myristyl (meth) acrylate), pentadecyl (meth) acrylate, cetyl (meth) acrylate ((meth) The number of alkyl-based carbons that make up alkyl esters, such as palm acrylate (also known as palmitate), heptadecyl (meth) acrylate, and octadecyl (meth) acrylate (also known as (meth) acrylate stearate) (Methyl) of 1 ~ 18 chain structure Alkyl acrylate
(Meth) acrylic acid naphthyl (meth) acrylate, dicyclopentyl (meth) acrylate, and the like;
Aryl (meth) acrylate, such as benzyl (meth) acrylate;
Cyclo (meth) acrylate, such as dicyclopentenyl (meth) acrylate;
(Meth) acrylic cycloalkenyloxyalkyl esters such as dicyclopentenyloxyethyl (meth) acrylate;
(Meth) acrylic acid imine;
(Meth) acrylic acid-containing (meth) acrylates such as (meth) acrylic acid propylene;
Hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxy (meth) acrylate Hydroxyl groups such as butyl ester, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate contain (meth) acrylates;
Substituted amino group-containing (meth) acrylates such as N-methylamine ethyl (meth) acrylate and the like. Here, the "substituted amino group" means a group in which one or two hydrogen atoms of an amine group are substituted with a group other than a hydrogen atom.

The acrylic resin may be selected from (meth) acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methyl methacrylamide, in addition to the (meth) acrylic acid ester, for example. A product obtained by copolymerizing one or more monomers.

The monomer constituting the acrylic resin may be only one kind, or two or more kinds. When there are two or more monomers constituting the acrylic resin, the combination and ratio of these can be arbitrarily selected.

The acrylic resin may have a functional group capable of bonding to another compound such as a vinyl group, a (meth) acrylfluorenyl group, an amine group, a hydroxyl group, a carboxyl group, or an isocyanate group. The functional group of the acrylic resin may be bonded to another compound through a cross-linking agent (F) described later, or may be directly bonded to another compound without passing through the cross-linking agent (F). The acrylic resin is bound to another compound by the above-mentioned functional group, and the reliability of a component obtained by using a composite sheet for forming a protective film tends to be improved.

In the present invention, a thermoplastic resin other than the acrylic resin (hereinafter referred to as a "thermoplastic resin") may be used in combination with the acrylic resin as the polymer component (A).
By using the aforementioned thermoplastic resin, the peelability of the protective film from the support sheet is improved, or the film for forming a thermosetting protective film easily follows the uneven surface of the adherend, and further suppresses the adherend and the thermosetting protective film. When voids are formed between the forming films.

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

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

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

The thermoplastic resin contained in the composition (III-1) for forming a protective film and the film for forming a thermosetting protective film may be one type, or two or more types. When the thermoplastic resin is two or more kinds, the combination and ratio of these can be arbitrarily selected.

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

The polymer component (A) may be compatible with the thermosetting component (B). In the present invention, when the composition (III-1) for forming a protective film contains a component that meets both of such a polymer component (A) and a thermosetting component (B), the composition (III-1) for forming a protective film ) Is considered to contain a polymer component (A) and a thermosetting component (B).

[Thermosetting component (B)]
The thermosetting component (B) is a component for curing a film for forming a thermosetting protective film to form a hard protective film.
The composition (III-1) for forming a protective film and the thermosetting component (B) contained in the film for forming a thermosetting protective film may be only one kind, or two or more kinds. When the thermosetting component (B) is two or more, the combination and ratio of these can be arbitrarily selected.

Examples of the thermosetting component (B) include an epoxy-based thermosetting resin, a thermosetting polyimide, a polyurethane, an unsaturated polyester, and a silicone resin. Resin is preferred.

(Epoxy-based 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 two or more types. When there are two or more epoxy-based thermosetting resins, the combination and ratio of these can be arbitrarily selected.

･ Epoxy resin (B1)
Examples of the epoxy resin (B1) include conventional ones, and examples thereof include polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl esters and hydrogenated products thereof, and o-cresol novolac rings. Epoxy resin, bicyclopentadiene epoxy resin, biphenyl epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, phenylene skeleton epoxy resin, etc. Compound.

As the epoxy resin (B1), an epoxy resin having an unsaturated hydrocarbon group can also be used. Compared with epoxy resins without unsaturated hydrocarbon groups, the compatibility of epoxy resins with unsaturated hydrocarbon groups and acrylic resins is higher. Therefore, the reliability of a module obtained by using an epoxy resin having an unsaturated hydrocarbon group and using a composite sheet for forming a protective film is improved.

Examples of the epoxy resin having an unsaturated hydrocarbon group include compounds obtained by converting a part of an epoxy group of a polyfunctional epoxy resin into a group having an unsaturated hydrocarbon group. Such a compound system can be obtained, for example, by addition reaction of an epoxy group with (meth) acrylic acid or its derivative.
Moreover, as an epoxy resin which has an unsaturated hydrocarbon group, the compound etc. which have a structure in which the group which has an unsaturated hydrocarbon group has the direct bond structure, and the aromatic ring of an epoxy resin etc. are mentioned, for example.
The unsaturated hydrocarbon group is a polymerizable unsaturated group. Specific examples thereof include vinyl (also referred to as vinyl), 2-propenyl (also referred to as allyl), (meth) acrylfluorenyl, The (meth) acrylfluorenyl group and the like are preferably an acrylfluorenyl group.
In the present specification, "derivative" means a substance in which at least one hydrogen atom of the original compound is substituted with a group (substituent) other than a hydrogen atom.

The number average molecular weight of the epoxy resin (B1) is not particularly limited. The curability of the film for forming a thermosetting protective film, and the strength and heat resistance of the cured protective film are preferably 300 to 30,000. 300 ~ 10000 is preferred, and 300 ~ 3000 is particularly preferred.
In this specification, "quantity average molecular weight" means the number average molecular weight represented by 値 in standard polystyrene conversion measured using a gel permeation chromatography (GPC) method unless previously notified.
The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1100 g / eq, and more preferably 150 to 1000 g / eq.
In this specification, the "epoxy equivalent" means the number of grams (g / eq) of an epoxy compound containing 1 equivalent of an epoxy group, and it can be measured according to the method of JISK7236: 2001.

The epoxy resin (B1) may be used singly or in combination of two or more types and in combination of two or more types of the epoxy resin (B1). These combinations and ratios can be arbitrarily selected.

･ Heat hardener (B2)
The thermosetting agent (B2) can function as a curing agent for the epoxy resin (B1).
Examples of the thermosetting agent (B2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the functional group include, for example, a phenolic hydroxyl group, an alcoholic hydroxyl group, an amine group, a carboxyl group, and an acidified group, and preferably a phenolic hydroxyl group, an amine group, or an acidified group is an anhydrous group. Of these, phenolic hydroxyl or amine groups are preferred.

Among the thermal hardeners (B2), examples of the phenolic hardener having a phenolic hydroxyl group include polyfunctional phenol resins, biphenyls, novolac-type phenol resins, dicyclopentadiene-based phenol resins, and aralkyl groups. Phenol resin and so on.
Among the thermal curing agents (B2), examples of the amine-based curing agent having an amine group include dicyanodiamide (hereinafter, "DICY" may be abbreviated as "the case").

The thermosetting agent (B2) may have an unsaturated hydrocarbon group.
Examples of the thermosetting agent (B2) having an unsaturated hydrocarbon group include compounds in which a part of hydroxyl groups of a phenol resin is substituted with a group having an unsaturated hydrocarbon group, and a group having an unsaturated hydrocarbon group directly bonded to the phenol resin. Compounds such as aromatic rings.
The unsaturated hydrocarbon group in the thermosetting agent (B2) is the same as the unsaturated hydrocarbon group of the epoxy resin having an unsaturated hydrocarbon group.

When a phenol-based hardener is used as the thermal hardener (B2), in terms of improving the peelability of the protective film from the support sheet, the thermal hardener (B2) preferably has a higher softening point or a higher glass transition temperature.

The heat curing agent (B2) is preferably a solid at room temperature and does not show hardening activity to the epoxy resin (B1). On the other hand, it is a heat that dissolves by heating and shows hardening activity to the epoxy resin (B1). A hardening agent (hereinafter sometimes referred to as a "thermally active latent epoxy resin hardener") is preferred.
The thermoactive latent epoxy resin hardener is a film for forming a thermosetting protective film at room temperature, which is stably dispersed in the epoxy resin (B1), but is compatible with the epoxy resin (B1) by heating. And it reacts with epoxy resin (B1). By using the aforementioned thermally active latent epoxy resin hardener, the storage stability of the protective film-forming composite sheet is significantly improved. For example, the curing agent can be prevented from moving from the film for forming a protective film to an adjacent supporting sheet, and the degradation of the thermosetting property of the film for forming a thermosetting protective film can be effectively suppressed. In addition, since the film for forming a thermosetting protective film has a high degree of thermosetting by heating, the pick-up property of the semiconductor wafer with a protective film described later is further improved.

Examples of the thermally active latent epoxy resin hardener include onium salts, hydrazine dibasic acid, dicyandiamine, and amine adducts of hardeners.

Among the thermal hardeners (B2), for example, the number average molecular weight of resin components such as polyfunctional phenol resin, novolac phenol resin, dicyclopentadiene-based phenol resin, and aralkylphenol resin is preferably 300 to 30,000. It is better to use 400 ~ 10000, especially 500 ~ 3000.
Among the thermosetting agents (B2), the molecular weight of non-resin components such as biphenol and dicyandiamine is not particularly limited, but is preferably 60 to 500, for example.

The thermosetting agent (B2) may be used singly or in combination of two or more kinds and in combination of two or more kinds of the thermosetting agent (B2). These combinations and ratios can be arbitrarily selected.

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 0.1 to 500 mass based on 100 parts by mass of the content of the epoxy resin (B1). Is preferably 1 to 200 parts by mass. When the content of the thermosetting agent (B2) is at least the aforementioned lower limit 値, the curing system of the film for forming a thermosetting protective film becomes easier. In addition, when the content of the thermosetting agent (B2) is equal to or less than the upper limit 値, the moisture absorption rate of the film for forming a thermosetting protective film can be reduced, and the reliability of a module obtained by using the composite sheet for forming a protective film is Further improvement.

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

[Hardening accelerator (C)]
The composition for forming a protective film (III-1) and the film for forming a thermosetting protective film may contain a hardening accelerator (C). The hardening accelerator (C) is a component for adjusting the hardening speed of the protective film-forming composition (III-1).
Examples of the preferred hardening accelerator (C) include third ethylene glycol, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and gins (dimethylaminomethyl) phenol. Primary amines; 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dimethylol imidazole, 2-phenyl-4-methyl Imidazoles such as -5-hydroxymethylimidazole (i.e., imidazole substituted with at least one hydrogen atom by a group other than a hydrogen atom); organic phosphines such as tributylphosphine, diphenylphosphine, triphenylphosphine ( That is, at least one hydrogen atom is substituted with an organic group as a phosphine); a triphenylphosphonium tetraphenylborate, a tetraphenylboron salt of a triphenylphosphine tetraphenylborate, and the like.

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

When the hardening accelerator (C) is used, the content of the hardening accelerator (C) in the composition (III-1) for forming a protective film and the thin film for forming a thermosetting protective film is relative to that of the thermosetting component (B). The content is 100 parts by mass, preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass. When the content of the hardening accelerator (C) is at least the aforementioned lower limit, the effect obtained by using the hardening accelerator (C) can be more significant. In addition, when the content of the hardening accelerator (C) is equal to or less than the aforementioned upper limit, for example, the high-polarity hardening accelerator (C) is inhibited from adhering to the film for forming a thermosetting protective film under high temperature and high humidity conditions. The effect of segregation of the object on the interface side is increased, and the reliability of the module obtained by using the composite sheet for forming a protective film is further improved.

[Filling material (D)]
The composition for forming a protective film (III-1) and the film for forming a thermosetting protective film may contain a filler (D). When the film for thermosetting protective film formation contains a filler (D), the protective film system obtained by curing the film for thermosetting protective film formation is easy to adjust the coefficient of thermal expansion, and the coefficient of thermal expansion The object to be formed is optimized, and the reliability of the module obtained by using the composite sheet for forming a protective film is further improved. In addition, when the film for forming a thermosetting protective film contains a filler (D), the moisture absorption rate of the protective film can be reduced or the heat release property can be improved.

The filler (D) may be either an organic filler or an inorganic filler, and an inorganic filler is preferred.
Examples of preferred inorganic fillers include powders of silicon oxide, aluminum oxide, talc, calcium carbonate, titanium white, iron oxide red, silicon carbide, boron nitride, and the like; and spheroidizing these inorganic fillers Surface beads of these inorganic fillers; single crystal fibers of these inorganic fillers; and glass fibers.
Among these, the inorganic filler is preferably silicon oxide or aluminum oxide.

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 kind, or two or more kinds. When there are two or more fillers (D), the combination and ratio of these can be arbitrarily selected.

When the filler (D) is used, the filler (the total mass of the protective film-forming composition (III-1)) in the protective film-forming composition (III-1) with respect to the total content of all components except the solvent (the total mass of the protective film-forming composition (III-1)) The content ratio of (D) (that is, the content of the filler (D) relative to the total mass of the thermosetting protective film-forming film) is preferably 5 to 80% by mass, and 7 to 60% by mass is preferred. good. When the content of the filler (D) is in such a range, it is easier to adjust the above-mentioned thermal expansion coefficient.

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

The coupling agent (E) is preferably a compound having a functional group capable of reacting with a functional group such as a polymer component (A), a thermosetting component (B), and the like, and a silane coupling agent is more preferable.
Examples of the preferable silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxy Propyltriethoxysilane, 3-glycidoxymethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloxy Propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-aminoethylamino) propylmethyl Diethoxysilane, 3- (aniline) propyltrimethoxysilane, 3-anilinepropyltrimethoxysilane, 3-uretyltriethoxysilane, 3-mercaptopropyltrimethoxysilane , 3-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxy Silane, vinyltriethoxysilane, imidazole silane, etc.

The coupling agent (E) contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be one type, or two or more types, and when the coupling agent (E) is two or more types The combination and ratio of these can be arbitrarily selected.

When the coupling agent (E) is used, the content of the coupling agent (E) in the protective film-forming composition (III-1) and the thermosetting protective film-forming film is based on the polymer component (A) and the thermosetting property. When the total content of the component (B) is set to 100 parts by mass, 0.03 to 20 parts by mass are preferred, 0.05 to 10 parts by mass is more preferred, and 0.1 to 5 parts by mass is particularly preferred. When the content of the coupling agent (E) is at least the aforementioned lower limit, the dispersibility of the filler (D) in the resin is improved, and the adhesion between the film for forming a thermosetting protective film and the adherend is improved. (E) The effect obtained can be more significant. In addition, when the content of the coupling agent (E) is equal to or less than the upper limit 値, generation of exhaust gas can be further suppressed.

[Crosslinking agent (F)]
As the polymer component (A), when a functional group such as a vinyl group, a (meth) acryl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group, such as the above-mentioned acrylic resin, which can be bonded to other compounds is used The composition for forming a protective film (III-1) and the film for forming a thermosetting protective film may contain a cross-linking agent (F) for bonding the functional group to another compound to crosslink. By crosslinking using a crosslinking agent (F), the initial adhesive force and cohesive force of the film for thermosetting protective film formation can be adjusted.

Examples of the cross-linking agent (F) include an organic polyisocyanate compound, an organic polyimide compound, a metal clamp compound-based cross-linking agent (that is, a cross-linking agent having a metal clamp compound structure), and acridine.糸 Crosslinking agent (that is, a crosslinking agent having an acryl propane group) and the like.

Examples of the organic polyisocyanate compound include an aromatic polyisocyanate compound, an aliphatic polyisocyanate compound, and an alicyclic polyisocyanate compound (hereinafter, these compounds are collectively referred to as an aromatic polyisocyanate compound, etc.) ); Terpolymers, isotricyanate bodies, and adducts of the aromatic polyisocyanate compounds; terminal isocyanate urethanes obtained by reacting the aromatic polyisocyanate compounds and the like with polyol compounds Things. The "adduct" means the aforementioned aromatic polyisocyanate compound, aliphatic polyisocyanate compound or alicyclic polyisocyanate compound, and ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil, etc. Examples of the reactant of the low-molecular active hydrogen-containing compound include benzyl diisocyanate adducts of trimethylolpropane as described below. The "terminal isocyanate urethane prepolymer" is as described above.

Specific examples of the organic polyisocyanate compound include 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; 1,3-benzenedimethyldiisocyanate; 1,4-xylene diisocyanate ; Diphenylmethane-4,4'-diisocyanate; Diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone di Isocyanates; Dicyclohexylmethane-4,4'-diisocyanate; Dicyclohexylmethane-2,4'-diisocyanate; Toluene diisocyanates such as trimethylolpropane, hexamethylene diisocyanate, and xylylene didimethyl Any one or two or more isocyanates are compounds obtained by adding all or part of the hydroxyl groups of a polyol; diamine diisocyanates and the like.

Examples of the organic polyimide compound include N, N'-diphenylmethane-4,4'-bis (1-acylcyclopropanecarboxamide), and trimethylolpropane-tri-β-acryl Cyclopropanyl propionate, tetramethylol methane-tri-β-acylcyclopropanyl propionate, N, N'-toluene-2,4-bis (I-acylcyclopropanecarboxamide) triethylene glycol Melamine and the like.

When an organic polyisocyanate compound is used as the crosslinking agent (F), it is preferable to use a polymer containing a hydroxyl group as the polymer component (A). When the cross-linking agent (F) has an isocyanate group and the polymer component (A) has a hydroxyl group, the cross-linking agent (F) can react with the polymer component (A) to easily introduce the cross-linked structure into the thermosetting protection. Film for film formation.

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

When using a cross-linking agent (F), the content of the cross-linking agent (F) in the protective film-forming composition (III-1) is based on 100 parts by mass of the content of the polymer component (A) and ranges from 0.01 to 20 Part by mass is preferred, 0.1 to 10 parts by mass is preferred, and 0.5 to 5 parts by mass is particularly preferred. When the content of the crosslinking agent (F) is at least the aforementioned lower limit 値, the effect obtained by using the crosslinking agent (F) can be more significant. In addition, when the content of the cross-linking agent (F) is equal to or less than the upper limit 値, the adhesion between the film for forming a thermosetting protective film and a support sheet, and the film for forming a thermosetting protective film and a semiconductor wafer or the like can be suppressed. The adhesive force of the semiconductor wafer is excessively low.
In the present invention, the effects of the present invention can be sufficiently obtained without using a crosslinking agent (F).

[Energy ray hardening resin (G)]
The protective film-forming composition (III-1) may contain an energy ray-curable resin (G). The thin film for forming a thermosetting protective film contains an energy ray-curable resin (G), and the characteristics can be changed by irradiating the energy ray.

The energy ray-curable resin (G) is a substance obtained by polymerizing (hardening) an energy ray-curable compound.
Examples of the energy ray-curable compound include a compound having at least one polymerizable double bond in the molecule, and an acrylate-based compound having a (meth) acrylfluorenyl group is preferable.

Examples of the acrylate-based compound include trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, neopentaerythritol tri (meth) acrylate, and Pentaerythritol tetra (meth) acrylate, dinepentaerythritol monohydroxypenta (meth) acrylate, dinepentaerythritol hexa (meth) acrylate, 1,4-butanediol di (methyl) ) (Meth) acrylic acid esters containing chain aliphatic skeletons such as acrylate, 1,6-hexanediol di (meth) acrylate; cyclic aliphatic skeletons including dicyclopentyl di (meth) acrylate (Meth) acrylates; polyalkylene glycol (meth) acrylates such as polyethylene glycol di (meth) acrylates; oligopolyester (meth) acrylates; urethanes (meth) Acrylate oligomers; epoxy-modified (meth) acrylates; polyether (meth) acrylates other than the aforementioned polyalkylene glycol (meth) acrylates; Iconic acid oligomers; and the like.

The weight-average molecular weight of the reenergy ray-curable compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

The energy ray-curable compound used in the polymerization may be one kind, or two or more kinds. When the energy ray-curable compound is two or more kinds, the combination and ratio of these can be arbitrarily selected.

The energy ray-curable resin (G) contained in the protective film-forming composition (III-1) may be one type, or two or more types. When the energy ray-curable resin (G) is two or more, the combination and ratio of these can be arbitrarily selected.

The content of the energy ray-curable resin (G) in the protective film-forming composition (III-1) is preferably 1 to 95% by mass based on the total mass of the protective film-forming composition (III-1). 2 to 90% by mass is preferred, and 3 to 85% by mass is particularly preferred.

[Photopolymerization initiator (H)]
When the protective film-forming composition (III-1) contains an energy ray-curable resin (G), a photopolymerization initiator may be contained in order to efficiently perform the polymerization reaction of the energy ray-curable resin (G). (H).

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

The photopolymerization initiator (H) contained in the protective film-forming composition (III-1) may be one type, or two or more types. When the photopolymerization initiator (H) is two or more, the combination and ratio of these can be arbitrarily selected.

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

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

Examples of the organic pigments and organic dyes include amine-based pigments, anthocyanin-based pigments, merocyanin-based pigments, croconium-based pigments, and squalium-based pigments. , Azulenium-based pigments, polymethine-based pigments, naphthoquinone-based pigments, pyranium-based pigments, phthalocyanine-based pigments, naphthalocyanine-based pigments, naphtholide ( (naphtholactam) pigments, azo pigments, condensed azo pigments, indigo pigments, perinone pigments, saccharine pigments, dioxazine pigments, quinacridone pigments, isoindoles Indolone pigments, quinophthalone pigments, pyrrole pigments, thioindigo pigments, metal complex pigments (metal salt dyes), dithiol metal complex pigments, Indole-type pigment, triallyl methane-type pigment, anthraquinone-type pigment, dixazine-type pigment, naphthol-type pigment, methylimine-type pigment, benzimidazolone-type pigment, pyranthron It is a pigment and a threne color.

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

The coloring agent (I) contained in the composition (III-1) for forming a protective film and the film for forming a thermosetting protective film may be one type, or two or more types. When there are two or more colorants (I), the combination and ratio of these can be arbitrarily selected.

When the colorant (I) is used, the content of the coloring agent (I) in the film for forming a thermosetting protective film may be appropriately adjusted according to the purpose. For example, the protective film may be printed by laser irradiation, and the visibility of the printing can be adjusted by adjusting the content of the coloring agent (I) of the film for forming a thermosetting protective film and adjusting the light transmittance of the protective film. . In addition, by adjusting the content of the coloring agent (I) of the thin film for forming a thermosetting protective film, it is possible to improve the pattern design of the protective film or to make it hard to see the grinding marks on the back surface of the semiconductor wafer. In consideration of this point, the content ratio of the colorant (I) to the total content of all components other than the solvent of the protective film-forming composition (III-1) (that is, the coloring agent for the film for forming a thermosetting protective film) The content of (I) is preferably 0.1 to 10% by mass, more preferably 0.1 to 7.5% by mass, and particularly preferably 0.1 to 5% by mass. When the content of the colorant (I) is at least the aforementioned lower limit 値, the effect obtained by using the colorant (I) can be more significant. In addition, when the content of the colorant (I) is equal to or less than the upper limit ，, it is possible to suppress an excessively low light transmittance of the film for forming a thermosetting protective film.

[General additives (J)]
The composition for forming a protective film (III-1) and the film for forming a thermosetting protective film are within a range not to impair the effects of the present invention, and may contain a general-purpose additive (J).
The general-purpose additive (J) may be a conventional one, and may be arbitrarily selected according to the purpose, and is not particularly limited. Preferred examples include plasticizers, antistatic agents, antioxidants, and deaerators.

The general-purpose additive (1) contained in the protective film-forming composition (III-1) and the thermosetting protective film-forming film may be only one kind, or two or more kinds. When there are two or more general-purpose additives (J), the combination and ratio of these can be arbitrarily selected.
The content of the protective film-forming composition (III-1) and the general-purpose additive (J) of the film for forming a thermosetting protective film is not particularly limited, and may be appropriately selected depending on the purpose.

[Solvent]
It is preferable that the composition (III-1) for forming a protective film further contains a solvent. The composition (III-1) for forming a protective film containing a solvent can improve the operability.
The solvent system is not particularly limited, and preferred examples include hydrocarbons such as toluene and xylene; methanol, ethanol, 2-propanol, isobutanol (2-methylpropane-1-ol), 1- Alcohols such as butanol; esters such as ethyl acetate and butyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; dimethylformamide and N-methylpyrrolidone Amido (a compound having an amido bond) and the like.
The solvent contained in the protective film-forming composition (III-1) may be only one kind, or two or more kinds. When there are two or more solvents, the combination and ratio of these can be arbitrarily selected.

In order to allow the contained components in the protective film-forming composition (III-1) to be more uniformly mixed, the solvent contained in the protective film-forming composition (III-1) is preferably methyl ethyl ketone or the like. .

<The manufacturing method of the composition for thermosetting protective film formation>
A composition for forming a thermosetting protective film such as the protective film-forming composition (III-1) can be obtained by blending each component constituting the composition.
The order in which the components are added is not particularly limited, and two or more components may be added simultaneously.
When a solvent is used, the solvent may be mixed with any formulation component other than the solvent, and the formulation component may be diluted before use, or any formulation component other than the solvent may not be diluted in advance, and the solvent may be mixed with the formulation component. Use for mixing.
The method of mixing the ingredients at the time of preparation is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or a stirring blade, a method of mixing using a mixer, and a method of mixing by applying an ultrasonic wave. Just fine.
The temperature and time during the addition and mixing of the components are not particularly limited as long as the prepared components do not deteriorate, and may be adjusted appropriately. The temperature is preferably 15 to 30 ° C.

In the same manner as the composite film for forming a protective film of the present invention, in order to be attached to a semiconductor wafer or a back surface of the semiconductor wafer opposite to the circuit surface, a dicing wafer is used as a composite sheet having a layer showing adhesiveness on a support sheet. Bonding sheet.
However, after the adhesive layer included in the dicing wafer bonding sheet is picked up from the supporting sheet together with the semiconductor wafer, it functions as an adhesive when mounting the semiconductor wafer on a substrate, lead frame, or other semiconductor wafer. On the other hand, the protective film-forming film of the protective film-forming composite sheet of the present invention is the same as the aforementioned adhesive layer in terms of being picked up from the supporting sheet together with the semiconductor wafer, but is finally protected by curing. The film has a function of protecting the back surface of the attached semiconductor wafer. As described above, the film for forming a protective film of the present invention and the adhesive layer for dicing a wafer bonding sheet have different applications and naturally require different properties. In addition, reflecting the difference in use, the film for forming a protective film is generally harder and more difficult to pick up than the adhesive layer for dicing a wafer bonding sheet. Therefore, it is generally difficult to directly transfer the adhesive layer of the dicing wafer bonding sheet as a thin film for forming a protective film on a composite sheet for forming a protective film. The composite sheet for forming a protective film of the present invention is one having a thin film for forming a thermosetting protective film, and is required to have excellent pick-up suitability for a semiconductor wafer with a protective film.

◇ Method for producing a composite sheet for forming a protective film The composite sheet for forming a protective film of the present invention can be produced by laminating sequentially in such a manner as to correspond to the positional relationship of the above-mentioned layers. The method of forming each layer is as described above.
For example, when manufacturing an adhesive layer on a base material when manufacturing a support sheet, the said adhesive composition may be apply | coated to a base material, and it may just dry as needed.

On the other hand, for example, when a film for forming a protective film is further laminated on an adhesive layer that has been laminated on a substrate, a composition for forming a protective film is applied on the adhesive layer to directly form a protective film. With film. A layer other than the thin film for forming a protective film may be formed on the adhesive layer by using a composition for forming the layer and using the same method. In this way, when a continuous two-layer laminated structure is formed by using any one of the compositions, a new layer can be formed by further applying the composition to a layer formed of the composition.
However, among these two layers, it is preferable that the later laminated layer is formed on another release film using the aforementioned composition in advance, and the side of the formed layer that is in contact with the release film is opposite The exposed surface on the side is bonded to the exposed surfaces of the remaining layers that have already been formed to form a continuous two-layer laminated structure. In this case, the composition is preferably applied on a release-treated surface of a release film. After the release film is formed into a laminated structure, it may be removed as necessary.

For example, a protective film-forming composite sheet (a support sheet is a laminate of a substrate and an adhesive layer) is produced by laminating an adhesive layer on a base material and laminating a protective film-forming film on the adhesive layer. (Composite sheet for forming a protective film), the adhesive composition is coated on the substrate and dried as necessary, and the adhesive layer is laminated on the substrate in advance, and the protective film The formation composition is applied to a release film, and if necessary, dried, a protective film-forming film is formed on the release film in advance. Then, the exposed surface of the protective film-forming film is bonded to the exposed surface of the adhesive layer laminated on the base material to laminate the protective film-forming film on the adhesive layer to obtain a protective film. Formation composite sheet.

When the adhesive layer is laminated on the substrate, as described above, the adhesive composition may be applied to a release film instead of applying the adhesive composition to the substrate, and may be applied as necessary. The adhesive layer is formed on the release film in advance, and the exposed surface of the layer is adhered to one surface of the substrate to laminate the adhesive layer on the substrate.
In either method, the release film may be removed at any timing after the target laminated structure is formed.

As described above, any layer other than the base material constituting the protective film-forming composite sheet can be laminated using a method previously formed on the release film and bonded to the surface of the target layer, so it is appropriately selected as necessary. Such a layer may be used to produce a protective film-forming composite sheet.

In addition, the protective sheet-forming composite sheet system can usually be stored in a state where the release film is bonded to the surface of the outermost layer (for example, the film for protective film formation) on the side opposite to the support sheet. Therefore, a composition for forming the outermost layer, such as a composition for forming a protective film, is applied to the release film (preferably, the release-treated surface), and the release film is dried in advance as necessary. The uppermost layer is formed thereon, and the remaining layers are laminated on the exposed surface of the layer on the opposite side from the side in contact with the release film by any of the methods described above. Even if the release film is not removed, it can be applied on the surface. In the closed state, a composite sheet for forming a protective film was obtained.

◎ Method for manufacturing semiconductor wafer with protective film The method for manufacturing semiconductor wafer with protective film of the present invention includes the following steps:
A step of manufacturing a laminated body by laminating a semiconductor wafer on the side of the film for forming a thermosetting protective film of the composite sheet for forming a protective film;
A step of irradiating laser light inside the laminated semiconductor wafer to form a modified layer inside the semiconductor wafer;
Cold-expanding the laminate at a temperature lower than normal temperature to divide the semiconductor wafer and the thermosetting protective film-forming film or the protective film; and dividing the thermosetting protection of the laminate The film for forming a film is subjected to heat curing to form a protective film.

The method for manufacturing a semiconductor wafer with a protective film according to the present invention may include the following steps in order: a semiconductor wafer is laminated on the side of the thermosetting protective film-forming film of the protective film-forming composite sheet to form a laminate. A step of irradiating laser light to the inside of the semiconductor wafer of the multilayer body to form a modified layer inside the semiconductor wafer after the bulk step; cold expanding the multilayer body at a temperature lower than normal temperature to expand the layer A step of dividing a semiconductor wafer and the thin film for forming a thermosetting protective film; and a step of heating and hardening the thin film for forming a thermosetting protective film of the laminate to form a protective film. An example of a manufacturing method of the semiconductor wafer with a protective film will be described using FIG. 3.

FIG. 3 is a cross-sectional view schematically showing an example of a method for manufacturing a semiconductor wafer with a protective film.
First, after grinding the back surface of the semiconductor wafer 18 to a desired thickness, the back surface of the semiconductor wafer 18 after the back grinding is adhered to the thermosetting protective film-forming film 23 of the protective film-forming composite sheet 2. At the same time, the composite sheet 2 for forming a protective film is fixed to the ring frame 17 (FIG. 3 (a)). When the back surface polishing tape 20 is attached to the surface (electrode formation surface) of the semiconductor wafer 18, the semiconductor wafer 18 is removed from the back surface polishing tape 20.

Next, from the side of the protective film-forming composite sheet 2, laser light (SD) is irradiated so as to be focused on the focus set inside the semiconductor wafer 18, and a modified layer 18 c is formed inside the semiconductor wafer 18. (Figure 3 (b)). Furthermore, laser printing is performed by irradiating laser light from the side of the support sheet 10 as necessary.

Next, the semiconductor wafer 18 is moved to a low-temperature environment together with the protective film-forming composite sheet 2 attached to the back surface, and is cold-expanded (CE) in the planar direction of the protective film-forming composite sheet 2 to protect the hardenability. At the same time that the thin film for film formation is cut, the semiconductor wafer 18 is divided into individual pieces at the portion of the modified layer 18c (Fig. 3 (c)). The temperature condition of the cold expansion (CE) may be a temperature lower than normal temperature, preferably -20 to 10 ° C, and more preferably -15 to 5 ° C. As necessary, infrared light is irradiated from the side of the support sheet 10 for infrared inspection.

In addition, the sample can be mounted on the expanded support sheet 10 (that is, the base material 11 and the adhesive layer 12) as necessary, and fixed in a state where the support sheet 10 is expanded. Alternatively, it can also be used by imparting heat shrinkability to the base material 11. After the support sheet 10 is cold-expanded, the heat shrinkability of the base material 11 can be used to remove slack in the support sheet 10. The test piece is fixed without being attached to the support sheet 10 in an expanded state. When the adhesive layer 12 is an energy ray-curable substance, it is preferable to mount the sample and fix the expanded support sheet 10, and then irradiate the energy layer to harden the adhesive layer 12 to make the adhesive After the layer 12 is hardened, the process proceeds to a step of hardening the thin film 23 for forming a thermosetting protective film.

Then, the support sheet 10, the laminated body 23 of the thermosetting protective film forming sheet, and the laminated semiconductor wafer 19 are heated to heat the thermosetting protective film forming film 23 to form a protective film. 23 '(Figure 3 (d)).

The protective film-forming composite sheet 2 which is adjusted to be described later and has good pick-up suitability is usually caused by cold expansion (CE) at a temperature lower than normal temperature between the adhesive layer 12 and the thermosetting protective film-forming film 23. Floating. However, the storage elastic modulus (G '(70)) of the adhesive layer 12 of the protective film-forming composite sheet 2 of the present invention at 70 ° C is 0.16 MPa or less, preferably 0.15 MPa or less, and preferably 0.10 MPa or less. Especially preferably, it is 0.06 MPa or less. Under the thermal curing conditions of the thin film 23 for forming a thermosetting protective film, the floating easily disappears without leaving a floating mark.

Moreover, the storage elastic modulus (G '(70)) at 70 ° C of the adhesive layer of the protective film-forming composite sheet of the present invention is preferably 0.01 MPa or more, particularly preferably 0.02 MPa or more, and is protected by thermosetting properties. When the film-forming thin film 23 is thermally cured, the adhesive layer 12 does not overflow from the ends due to being too soft.

Finally, the semiconductor wafer 19 is peeled from the support sheet 10 together with the protective film 23 'attached to the back surface of the semiconductor wafer 19 and picked up to obtain the semiconductor wafer 19 with the protective film 23' (Fig. 3 (e)). When the adhesive layer 12 is an energy ray-curable substance, the adhesive layer 12 is hardened by irradiating energy rays as necessary, and from the cured adhesive layer 12, the semiconductor wafer 19 and a protective film attached to the back surface thereof When 23 'is picked up together, the semiconductor wafer 19 with the protective film 23' can be obtained more easily.

In FIG. 3, the example of the manufacturing method of the semiconductor wafer with a protective film using the protective film formation composite sheet 2 with the adhesive layer 16 for jigs was demonstrated, using the protection without the adhesive layer 16 for jigs The example of the manufacturing method of the semiconductor wafer with a protective film of the film formation composite sheet 1 is also the same.

In addition, in FIG. 3, laser light (SD) is irradiated from the side of the protective film-forming composite sheet 2 so as to be focused on a focus set inside the semiconductor wafer 18 to form a reformer inside the semiconductor wafer 18. The quality layer, but is not limited to this, and may be sequentially provided with a step of forming the aforementioned reforming layer; a step of becoming the aforementioned laminate; a step of dividing; and a step of becoming the aforementioned protective film. Specifically, for example, it may be A modified layer is formed inside the semiconductor wafer 18 to which the back-side polishing tape 20 is attached, and a protective film-forming composite sheet 2 is attached to the semiconductor wafer 18 where the modified layer is formed. Subsequently, laser light is irradiated from the side of the support sheet 10 to perform laser printing, and the semiconductor wafer 19 with the protective film 23 'can be obtained by cold expansion (CE), thermal curing, infrared inspection, and pickup.

◎ After the method of manufacturing a semiconductor device, the same method as in the previous method can be used to connect the obtained semiconductor wafer with a protective film to the flip chip on the circuit surface of the substrate with the protective film attached. (Flip Chip), as a semiconductor device. Furthermore, the semiconductor device may be used to manufacture a target semiconductor device.

In one aspect of the present invention, the protective sheet-forming composite sheet is a three-layer transparent film (thickness: 60) composed of a mixed resin of polypropylene (PP) and an olefin-based thermoplastic elastomer (TPO) as a base material. ~ 150μmm, 23 ° C Young's modulus 1 ~ 100MPa, matte surface / gloss two substrates; as an adhesive layer (thickness: 3 ~ 20μm, storage modulus at 70 ° C is 0.01 ~ 0.06MPa, and at 23 ° C) Adhesive composition (containing polymer components: 70-80 parts by mass of (meth) acrylate copolymer (2-ethylhexyl acrylate (2EHA), acrylic acid Copolymer obtained by copolymerizing 20 to 30 parts by mass of 2-hydroxyethyl ethyl ester (HEA), 100 parts by mass of weight average molecular weight: 700,000 to 900,000), and crosslinking agent component: trifunctional xylene diisocyanate-based crosslinking 20 parts by mass of a non-energy ray-curable adhesive composition); and a composition for forming a protective film (containing a polymer component: methyl acrylate) as a film (thickness: 5 to 50 μm) for forming a thermosetting protective film 80 to 90 parts by mass and 10 to 20 parts by mass of 2-hydroxyethyl acrylate copolymerized acrylic polymer (flat weight Molecular weight: 300,000 to 450,000, Tg: 1 to 10 ° C) 150 parts by mass, epoxy resin (bisphenol A type epoxy resin (epoxy equivalent 184 to 194 g / eq), 60 parts by mass, bisphenol A type epoxy resin (Epoxy equivalent 800 ~ 900g / eq) 10 parts by mass, dicyclopentadiene epoxy resin (epoxy equivalent 255 ~ 260g / eq) 30 parts by mass), hardener (dicyanodiamine (active hydrogen amount 21g / eq) 2 parts by mass, 2 parts by mass of a hardening accelerator (2-phenyl-4,5-dimethylol imidazole), 320 parts by mass of a filler (silica oxide filler (average particle diameter 0.5 μm)), a coupling agent ( A protective film-forming composition) containing 2 parts by mass of a silane coupling agent) and 18 parts by mass of a coloring agent (black pigment).

In another aspect of the present invention, the protective sheet-forming composite sheet is a three-layer transparent film (thickness: 80 μm, made of a mixed resin of polypropylene (PP) and olefin-based thermoplastic elastomer (TPO)) as a base material. Young's modulus at 23 ° C 50 MPa, matte surface / glossy substrate; as an adhesive layer (thickness: 5 μm, storage elastic modulus at 70 ° C. is 0.03 MPa, and storage elastic modulus at 23 ° C. is 0.31 MPa) An adhesive composition (containing a polymer component: (meth) acrylate copolymer (80 parts by mass of 2-ethylhexyl acrylate (2EHA) and 20 parts by mass of 2-hydroxyethyl acrylate (HEA)) was copolymerized. The copolymer obtained. Weight average molecular weight: 800,000) 100 parts by mass, and a crosslinking agent component: 20 parts by mass of a trifunctional xylene diisocyanate-based crosslinking agent (non-energy-ray-curable adhesive composition); and A composition for forming a protective film (containing a polymer component: 85 parts by mass of methyl acrylate and 15 parts by mass of 2-hydroxyethyl acrylate) as a composition for forming a thermosetting protective film (thickness: 25 μm) Acrylic polymer (weight average molecular weight: 370,000. Tg: 6 ° C) 150 mass 60 parts by mass of epoxy resin (bisphenol A type epoxy resin (epoxy equivalent 184 to 194 g / eq), 10 parts by mass of bisphenol A epoxy resin (epoxy equivalent 800 to 900 g / eq), bicyclic 30 parts by mass of pentadiene epoxy resin (epoxy equivalent 255 to 260g / eq), 2 parts by mass of hardener (dicyandiamine (active hydrogen amount 21g / eq)), hardening accelerator (2-phenyl -4,5-dimethylol imidazole) 2 parts by mass, filler (silica oxide filler (average particle size 0.5 μm)) 320 parts by mass, coupling agent (silane coupling agent) 2 parts by mass, and coloring agent (black pigment ) 18 parts by mass of the composition for forming a protective film).
[Example]

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

(Manufacture of a protective film-forming composition (III-1))
The components used in the production of the protective film-forming composition are shown below.
･ Polymer composition
(a): An acrylic polymer obtained by copolymerizing 85 parts by mass of methyl acrylate and 15 parts by mass of 2-hydroxyethyl acrylate (weight average molecular weight: 370,000. Tg: 6 ° C)
･ Epoxy resin
(b1) -1: Bisphenol A epoxy resin (jER828 manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 184 ~ 194g / eq)
(b1) -2: Bisphenol A epoxy resin (jER1055 manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 800 ~ 900g / eq)
(b1) -3: Dicyclopentadiene epoxy resin (Epiclon HP-7200HH, manufactured by DIC, epoxy equivalent 255 ~ 260g / eq)
·hardener
(b2): Dicyandiamine (manufactured by ADEKA, ADEKA HARDENER EH-3636AS, active hydrogen content 21g / eq))
Hardening accelerator
(c): 2-phenyl-4,5-dimethylol imidazole (CUREZOLE 2PHZ, manufactured by Shikoku Chemical Industries, Ltd.)
･ Filling agent
(d) Silica filler (average particle diameter of SC2050MA manufactured by ADMATECHS Co., 0.5 μm)
合 Couplings
(e): Silane coupling agent (manufactured by UNICAR of Japan, A-1110)
·Colorant
(i): Black pigment (manufactured by Daiichi SEIKI)

Polymer component (a), epoxy resin (b1) -1, epoxy resin (b1) -2, epoxy resin (b1) -3, hardener (b2), hardening accelerator (c), and filler (d), coupling agent (e) and coloring agent (i), so that the content (solid content, mass parts) becomes 150/60/10/30/2/2/320/2/18 or The composition (III-1) for protective film formation was dispersed in methyl ethyl ketone and stirred at 23 ° C. to prepare a solid content concentration of 52% by mass.

(Manufacture of an adhesive composition (I-4-1)).
･ Polymer composition
(A1): A copolymer obtained by copolymerizing 80 parts by mass of a (meth) acrylate copolymer (2-ethylhexyl acrylate (2EHA) and 20 parts by mass of 2-hydroxyethyl methacrylate (HEA). Weight (Average molecular weight: 800,000)
成分 crosslinker ingredients
(C): Trifunctional xylene diisocyanate-based crosslinking agent (Mitsui Takeda Chemical Co., Ltd., trade name "TAKENATE (registered trademark) D-110N")

A polymer component (A1) (100 parts by mass, solid content) and a crosslinker component (c) (25 parts by mass, solid content) were prepared, and methyl ethyl ketone was included as a solvent, and the solid content concentration was 30 masses % Non-energy ray hardening adhesive composition (I-4-1).

(Manufacturing of adhesive composition (I-4-2))
･ Polymer composition
(A1) A copolymer obtained by copolymerizing (mass) acrylate copolymer (80 parts by mass of 2-ethylhexyl acrylate (2EHA) and 20 parts by mass of 2-hydroxyethyl methacrylate (HEA). Weight average Molecular weight: 800,000)
成分 crosslinker ingredients
C): Trifunctional xylene diisocyanate crosslinking agent (Mitsui Takeda Chemical Co., Ltd., trade name "TAKENATE (registered trademark) D-110N")

A polymer component (A1) (100 parts by mass, solid content) and a crosslinker component (C) (1 part by mass, solid content) were prepared, and methyl ethyl ketone was included as a solvent, and the solid content concentration was 30 mass % Non-energy ray hardening adhesive composition (I-4-2).

(Manufacture of adhesive composition (I-4-3))
･ Polymer composition
(A1) (Meth) acrylate copolymer (2-ethylhexyl acrylate (2EHA) 60 parts by mass, methyl methacrylate (MMA) 30 parts by mass, 2-hydroxyethyl methacrylate (HEA) 10 Copolymer obtained by copolymerizing parts by mass. Weight-average molecular weight: 800,000)
成分 crosslinker ingredients
(C): Trifunctional xylene diisocyanate-based crosslinking agent (Mitsui Takeda Chemical Co., Ltd., trade name "TAKENATE (registered trademark) D-110N")

A solid content concentration containing a polymer component (A1) (100 parts by mass, solid content) and a crosslinker component (C) (20 parts by mass, solid content) and containing methyl ethyl ketone as a solvent was prepared to 30 mass % Non-energy ray hardening adhesive composition (I-4-3).

[Example 1]
<Manufacture of a protective sheet-forming composite sheet>

(Manufacture of support sheet)
3-layer transparent film (thickness: 80 μm, Young's modulus of 23 MPa, 50 MPa, matte surface / glossy surface) composed of a mixed resin of polypropylene (PP) and olefin-based thermoplastic elastomer (TPO) as a base material Material) was coated on the matte side of the adhesive composition (I-4-1) obtained above and heated and dried at 100 ° C for 2 minutes to obtain a non-woven fabric having a thickness of 5 μm on one surface of the substrate. The transparent support sheet (10) -1 of the energy ray hardening adhesive layer. By applying the adhesive composition to the matte surface, the matte surface is buried, light scattering is reduced, and transparency is improved.

(Manufacture of protective film-forming composite sheet)
The obtained protective film-forming composition (III-1) was coated on a polyethylene terephthalate film-formed one side with a silicone coating and a peeling film (manufactured by LINTEC Corporation) with a die coater. ISP-PE1381031 "and a thickness of 38 µm) were dried at 100 ° C for 2 minutes to produce a film (13) -1 for forming a thermosetting protective film having a thickness of 25 µm.

Next, the release film is removed from the adhesive layer of the support sheet (10) -1 obtained above, and the exposed surface of the film (13) -1 for forming the thermosetting protective film obtained above is bonded to the adhesive The protective film of Example 1 was produced by laminating the substrate, the adhesive layer, the film (13) -1 for forming a thermosetting protective film, and the release film in this order in the thickness direction. Formation composite sheet.

(Measurement of thickness)
The measurement was performed using a constant-pressure thickness measuring device (manufactured by Teclock Corporation, product name "PG-02").

＜ Test of elastic modulus of adhesive layer ＞
The adhesive composition (I-4-1) is coated on the release surface of a release sheet to form an adhesive layer, and the release surface of a separately prepared release sheet is pressure-bonded to the exposed adhesive layer to produce a release sheet / adhesive Adhesive sheet consisting of a layer / release sheet. The peeling sheet was peeled from this adhesive sheet peeling sheet, and the multiple layer was laminated so that the adhesive layer might become 200 micrometers in thickness. From the obtained laminated body of the adhesive layer, a 30 mm × 4 mm rectangle (thickness: 200 μm) was punched out, and this was used as a measurement sample.

Using a dynamic viscoelasticity measuring device ("RheovibronD DV-II-EP1" manufactured by ORIENTEC Corporation) in a measurement mode: tensile mode, frequency: 11 Hz, measurement temperature range: -20 to 150 ° C, ascent speed: 3 The storage elastic modulus was measured under the condition of ℃ / min, and the readings of 23 ℃ and 70 ℃ were read.

<Test for measuring the adhesive force (before hardening) between the protective film-forming film and the adhesive layer>
After the composite sheet for forming a protective film was produced, and after aging at 23 ° C for one week, the adhesive force between the protective film-forming film and the support sheet (adhesive layer) was measured for the test piece by the following method.
The release film cut into a protective film-forming composite sheet with a width of 25 mm and a length of 250 mm was removed, and the exposed surface was attached to the mirror wafer with a 2 kg roller so that the protective film formation layer contacted the mirror wafer surface at a time. After standing still at 23 ° C. and 50 RH for 20 minutes, peeling was performed at a peeling speed of 300 mm / min between the protective film-forming film and the adhesive layer of the support sheet at an angle of 180 °. This peeling force (mN / 25mm) was used as the adhesive force (before hardening) between the protective film-forming film and the adhesive layer.

<Cold expansion test and test for floating marks>
The protective film-forming layer of the protective film-forming composite sheet was attached to a silicon wafer with a back-grinding tape (diameter) after heating at 70 ° C using a tape bonding machine (ADWILL RAD-2700 manufactured by LINTEC). : 8 inches, thickness: 150 μm, ground surface: # 2000). After peeling the back abrasive tape. A laser saw (DFF7361, manufactured by DISCO Corporation) was used to irradiate the silicon wafer with laser light having a wavelength of 1342 nm from the grinding surface side, and a modified layer was formed inside the silicon wafer so that the wafer size became 7 mm × 7 mm. Next, using an expander (DDS2300, manufactured by DISCO), cold expansion was performed under the conditions of a push-up height: 20mm, a push-up speed: 20mm / s, and a temperature: -15 ° C to form a silicon wafer into 7 × pieces. At the same time as the 7 mm wafer, the film for forming a thermosetting protective film was cut. Then, the jig (sample) is mounted on the support sheet and held in an expanded state, and the adhesive sheet is attached to the opposite side (that is, the wafer side) from the support sheet.

Subsequently, the wafer was peeled from the support sheet and observed for floating marks. With this adhesive sheet attaching operation, even if the support sheet is peeled off, it can be observed that the individual wafers are not scattered. By observing with a digital microscope from the grinding surface side of the silicon wafer, the color of the outer peripheral portion of the silicon wafer having a structure (floating) between the adhesive layer and the film for forming the thermosetting protective film changes. In this way, the presence or absence of floating marks before curing is evaluated.

No swelling was observed. Swelling (peeling) was not observed between the adhesive layer and the film for forming a thermosetting protective film.
There is a floating mark, and it can be observed that floating (peeling) occurs between the adhesive layer and the film for forming a thermosetting protective film.

<Cold expansion test and test for disappearance of floating marks>
Similarly, with the wafer size of 7 mm × 7 mm, a laser light is used to form a modified layer inside the silicon wafer after the back grinding with the back grinding tape is completed, and the protective film forming composite sheet is formed. The protective film is formed on a ground surface of a silicon wafer while being heated at 70 ° C. The expander (DISCO, DDS2300) was cold-expanded under the conditions of a push-up height: 20mm, a push-up speed: 20mm / s, and a temperature: -15 ° C to form individual silicon wafers into 7 × 7mm At the same time as the wafer, the film for forming a thermosetting protective film is cut. Then, the jig (sample) is mounted on the support sheet and held in an expanded state, and the adhesive sheet is attached on the opposite side (that is, the wafer side) from the support sheet. Subsequently, it heat-hardened on 130 degreeC and 2 hours conditions, and the thin film for thermosetting protective film formation became a protective film.

Subsequently, when the support sheet was peeled off and viewed from the grinding surface side of the silicon wafer with a digital microscope, the color of the outer peripheral portion of the system-type silicon wafer that floated (peeled) between the adhesive layer and the protective layer was changed. To evaluate whether there are traces of floating after hardening.
The non-floating surface was not observed to cause lifting (peeling) between the adhesive layer and the protective layer.
There is a floater, and it can be observed that a floater (peeling) occurs between the adhesive layer and the protective layer.

＜ Pick up test ＞
A silicon wafer (diameter: 6 inches, thickness 150 μm, ground surface: gauge # 2000) with a back grinding tape after back grinding was performed using a laser saw (DFF7361, manufactured by DISCO Corporation) with a wavelength of 1342 nm. The light is irradiated from the grinding surface side, and a modified layer is formed inside the silicon wafer so that the wafer size becomes 5 mm × 5 mm. Using a tape bonding machine (ADWI11RAD-2700 manufactured by LINTEC Corporation), the surface of the protective film-forming film of the protective film-forming composite sheet was attached to the silicon wafer grinding surface while heating at 70 ° C. Cold expansion was performed using an expander (manufactured by DISCO Corporation, DDS2300) under the conditions of a push-up height: 20mm, a push-up speed: 20mm / s, and a temperature: -15 ° C. The sample was mounted on a support sheet and fixed to the expanded status. Thereby, the silicon wafer is singulated into 5 × 5 mm wafers, and the thin film for forming a protective film is cut.

Then, heat-harden at 130 ° C for 2 hours. Use a No. 5 needle (number of needles: 1 needle, "No. 5 silk needle" specified in "JISS3008 Hand Stitch Needle") as the needle for push-up and attach it to The device of the PUSH-PULL GAUGE ("MODEL-RE" manufactured by AIKOH ENGINEERING Co., Ltd.) is a semiconductor with a protective film attached to it through a support sheet under the conditions of a push-up amount: 3.0 mm and a push-up speed: 1 mm / s Push the wafer up. From the support sheet side, push up with a needle, and visually evaluate the wafer defect and peeling of the protective layer from the wafer according to the following criteria.

○ ･ ･ ･ No wafer defect was observed in any of the 10 wafers during the test. The protective layer was peeled from the wafer.
× ･ ･ ･ For 10 wafers, during the test, wafer defects occurred in at least one wafer, and the protective layer was peeled from the wafer.

The measurement results of the storage elastic modulus (G '(70)) of the adhesive layer of the protective film-forming composite sheet of Example 1 at 70 ° C and the storage elastic modulus (G' (23)) at 23 ° C. Shown in Table 1. In the composite sheet for forming a protective film of Example 1, the observation after cold expansion was shown in a microscope image in FIG. 4 (a), and it was shown that the adhesive layer and the thermosetting protective film were near the cut-off boundary of the semiconductor wafer. Floating occurs between the forming films, but as shown in FIG. 4 (b), the floating disappears under the condition of subsequent thermal curing at 130 ° C. Furthermore, the semiconductor wafer with a protective film can be picked up satisfactorily. Table 1 shows the measurement results of the adhesion between the protective film-forming film and the adhesive layer (before curing).

[Comparative Example 1]
<Production and evaluation of protective film-forming composite sheet>
A protective film of Comparative Example 1 was produced in the same manner as in Example 1 except that the adhesive composition (I-4-1) used in Example 1 was changed to the adhesive composition (I-4-2). Formation composite sheet.

The adhesive layer of the protective film-forming composite sheet of Comparative Example 1 had a storage elastic modulus (G '(70)) at 70 ° C, a storage elastic modulus (G' (23)) at 23 ° C, and a floating mark. Table 1 shows the results of the generated test, the test for the disappearance of floating marks, the pick-up test, and the adhesion force (before hardening) between the film for forming a protective film and the adhesive layer.

[Comparative Example 2]
<Production and evaluation of protective film-forming composite sheet>
A protective film of Comparative Example 1 was produced in the same manner as in Example 1 except that the adhesive composition (I-4-1) used in Example 1 was changed to the adhesive composition (I-4-3). Formation composite sheet.

The adhesive layer of the protective film-forming composite sheet of Comparative Example 2 had a storage elastic modulus (G '(70)) at 70 ° C, a storage elastic modulus (G' (23)) at 23 ° C, and floating marks. Table 1 shows the results of the generated test, the test for the disappearance of floating marks, the pick-up test, and the adhesion force (before hardening) between the film for forming a protective film and the adhesive layer.

[Table 1]

As is clear from the results in Table 1, in the manufacture of the semiconductor wafer using the protective film-forming composite sheet of Example 1, the storage elastic modulus (G '(70)) of the adhesive layer at 70 ° C was 0.16 MPa. Hereinafter, the storage elastic modulus (G '(23)) at 23 ° C is 0.10 MPa or more, and the floating between the adhesive layer and the film for forming a thermosetting protective film generated after cold expansion, Under the condition of subsequent thermal curing at 130 ° C, the adhesive layer can be disappeared due to the low elastic modulus of the adhesive layer, and no floating marks can be left, and the semiconductor wafer with the protective film can be picked up well.
In the manufacture of a semiconductor wafer using the protective film-forming composite sheet of Comparative Example 1, the storage elastic modulus (G '(70)) of the adhesive layer at 70 ° C was 0.16 MPa or less, but because of the storage elasticity at 23 ° C The modulus (G '(23)) is less than 0.10 MPa, and the floating generated between the adhesive layer and the film for forming a thermosetting protective film after cold expansion disappears under the attaching condition of 70 ° C, but because The semiconductor wafer with a protective film is excessively adhered to the adhesive layer, so it cannot be picked up well.
The protective film-forming composite sheet of Comparative Example 2 is a composite sheet having a general composition in which a semiconductor wafer and a protective film are divided together using a dicing blade. In the manufacture of a semiconductor wafer using the protective film-forming composite sheet of Comparative Example 2, although the storage elastic modulus (G '(23)) of the adhesive layer at 23 ° C was 0.10 MPa or more, it was because of the storage elasticity at 70 ° C. The modulus (G '(70)) is greater than 0.16 MPa, so the floating between the adhesive layer and the thermosetting protective film-forming film generated after cold expansion, even under the conditions of subsequent 130 ° C heat curing It does not disappear and traces of floating remain.
Industrial availability

The protective film-forming composite sheet of the present invention is suitable for producing a semiconductor wafer with a protective film by a method of dividing by applying cold expansion.

1, 2‧‧‧ composite sheet for protective film formation

10‧‧‧ support sheet

10a‧‧‧ surface of support sheet

11‧‧‧ Substrate

11a‧‧‧ Substrate surface

12‧‧‧ Adhesive layer

12a‧‧‧ Surface of the adhesive layer

13, 23‧‧‧ Films for forming thermosetting protective films

13a, 23a ‧‧‧ film surface for forming thermosetting protective film

13 ’, 23’‧‧‧ protective film

15‧‧‧ peeling film

15a‧‧‧ peel film surface

16‧‧‧ Adhesive layer for fixture

17‧‧‧ ring frame

18‧‧‧Semiconductor wafer (silicon wafer)

18a‧‧‧Side of semiconductor wafer

18c‧‧‧Modified layer

19‧‧‧Semiconductor wafer

20‧‧‧Backside abrasive tape

SD‧‧‧laser light

CE‧‧‧Cold Expansion

FIG. 1 is a cross-sectional view schematically showing an embodiment of a composite sheet for forming a protective film 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 cross-sectional view schematically showing an example of a method for manufacturing a semiconductor wafer with a protective film.

FIG. 4 is (a) a microscope photograph of a semiconductor wafer with a protective film that is not hardened after cold expansion. (b) Micrograph of a semiconductor wafer with a protective film after heat curing.

Claims (6)

A composite sheet for forming a protective film comprises a substrate, an adhesive layer, and a film for forming a thermosetting protective film in this order, The storage elastic modulus (G '(70)) of the adhesive layer at 70 ° C is 0.16 MPa or less, and the storage elastic modulus (G' (23)) at 23 ° C is 0.10 MPa or more. The composite sheet for forming a protective film according to item 1 of the scope of the patent application, wherein the storage elastic modulus (G '(70)) of the aforementioned adhesive layer at 70 ° C is 0.01 MPa or more. The composite sheet for forming a protective film according to item 1 or 2 of the scope of the patent application, wherein the storage elastic modulus (G '(23)) of the aforementioned adhesive layer at 23 ° C is 0.45 MPa or less. The composite film for forming a protective film according to item 3 of the scope of the patent application, wherein the adhesive layer is non-energy ray-curable or energy ray-curable. The composite film for forming a protective film according to item 3 or 4 of the scope of patent application, wherein the thickness of the aforementioned adhesive layer is 3 to 20 μm. A method for manufacturing a semiconductor wafer with a protective film includes the following steps: A step of laminating a semiconductor wafer on the side of the film for forming a thermosetting protective film of the composite sheet for forming a protective film according to any one of claims 1 to 5 to form a laminate; A step of irradiating laser light inside the semiconductor wafer to form a modified layer inside the semiconductor wafer; Cold-expanding the laminated body at a temperature lower than normal temperature to divide the semiconductor wafer and the thin film for forming the thermosetting protective film; A step of heating and curing the thin film for forming a thermosetting protective film of the laminated body to form a protective film.