JP6659308B2 - Sheet for forming first protective film - Google Patents

Description

  The present invention relates to a curable resin film and a first protective film forming sheet using the same.

  Conventionally, when a multi-pin LSI package used for an MPU, a gate array, or the like is mounted on a printed wiring board, a convex electrode (bump) made of eutectic solder, high-temperature solder, gold, or the like is used as a semiconductor chip on a connection pad portion thereof. ) Is formed, and a so-called face-down method has been adopted in which a flip-chip mounting method is employed in which the bumps are brought into face-to-face contact with corresponding terminal portions on a chip mounting substrate, and fusion / diffusion bonding is performed. .

  The semiconductor chip used in this mounting method is obtained, for example, by grinding or dicing a surface of a semiconductor wafer having a bump formed on a circuit surface, the surface being opposite to the circuit surface. In the process of obtaining such a semiconductor chip, usually, for the purpose of protecting the circuit surface and the bump of the semiconductor wafer, a curable resin film is attached to the bump forming surface, and the film is cured to protect the bump forming surface. Form a film. This curable resin film is typically attached to a bump-forming surface and then heated to increase the fluidity, so that the upper region including the top of the bump and its vicinity is exposed through the bump, and The bumps are buried so as to cover the surface of the bump, in particular, the surface near the circuit surface, while being in close contact with the circuit surface. The protective film formed by curing the curable resin film in this state protects the bump on the circuit surface in a state of being in close contact with the surface.

By the way, in the whole manufacturing process of a semiconductor device, by covering any part of a semiconductor element such as a semiconductor chip with a cured product of a resin composition, a target part such as the above-described protective film can be protected, It is common to seal. In this case, if chloride ions (Cl ⁻ ) are present as impurities in the cured product, a conductive portion such as a circuit may be corroded, or a metal may be deposited between circuits and short-circuited. It is presumed that the deposition of the metal is caused by the precipitation of the metal constituting the electrode and the wiring in the cured product due to the presence of chloride ions, and is particularly likely to occur under high temperature and high humidity conditions. Then, reduction of the content of chloride ions in the cured product of the resin composition has been studied.

  Examples of the resin composition that provides such a cured product include a specific thermosetting resin and a compound having a sulfide bond and an alkoxysilyl group, and include a halogen ion such as a chloride ion in the cured product. An adhesive composition for semiconductors having a concentration of at least 15 ppm (see Patent Document 1) and an epoxy resin composition for a sealing material containing an epoxy resin and having a minimum concentration of 3 ppm of chloride ions in a cured product (patent) Reference 2) is disclosed.

Japanese Patent No. 4352282 Japanese Patent No. 5393207

  However, none of the resin compositions disclosed in Patent Literatures 1 and 2 are intended to protect the bump-formed surface. There is no disclosure of a resin composition capable of forming a resin having reduced content. On the bump formation surface, the bump is formed on the circuit surface, and the shape of the bump is a convex shape, for example, a shape similar to a sphere, and the proportion of the bump surface in the region on the circuit surface is high. Has become. Accordingly, the protection film on the bump formation surface is more likely to be short-circuited than the protection film on the normal circuit surface where no bump exists. Therefore, it is unclear whether short-circuiting can be prevented even when a curable resin film made of a conventional resin composition as disclosed in Patent Documents 1 and 2 is used as it is for forming a protective film on a bump formation surface. However, use of such a curable resin film is not desirable from the viewpoint of preventing short circuit.

  Therefore, an object of the present invention is to provide a curable resin film capable of forming a protective film having a reduced chloride ion content on a bump forming surface of a semiconductor wafer, and a protective film forming sheet using the same. And

In order to solve the above-mentioned problem, the present invention is directed to a curable resin film for forming a first protective film on the surface by attaching and curing the surface of a semiconductor wafer having bumps, When the resin film is cured to form a cured product, chloride ions are extracted with hot water from the cured product at 125 ° C. for 20 hours, and the concentration of chloride ions in the obtained extracted water is measured. A curable resin film having a chloride ion content of 6 ppm or less based on the mass of the cured product.
Further, the present invention provides a first protective film forming sheet provided with the thermosetting resin film on one surface of a first support sheet.

  According to the present invention, there is provided a curable resin film capable of forming a protective film having a reduced chloride ion content on a bump forming surface of a semiconductor wafer, and a protective film forming sheet using the same.

It is sectional drawing which shows typically an example of the state in which the 1st protective film was formed in the bump formation surface using the curable resin film of this invention. It is sectional drawing which shows typically one Embodiment of the sheet | seat for 1st protective film formation of this invention. FIG. 4 is a cross-sectional view schematically showing another embodiment of the first protective film forming sheet of the present invention. It is sectional drawing which shows further another embodiment of the sheet | seat for 1st protective film formation of this invention typically.

The curable resin film of the present invention is a curable resin film for forming a first protective film on the surface by sticking and curing on a surface of a semiconductor wafer having bumps, wherein the curable resin film Was cured to obtain a cured product, and at 125 ° C. for 20 hours, chloride ions were extracted from the cured product with hot water, and the concentration of chloride ions in the obtained extracted water was measured. The content of chloride ions is 6 ppm or less based on the mass of the cured product.
Further, a sheet for forming a first protective film of the present invention is provided with the curable resin film of the present invention on one surface of a first support sheet. In the first protective film forming sheet, the “curable resin film” may be referred to as a “curable resin layer”.

The first protective film forming sheet of the present invention is used by being attached to the surface of a semiconductor wafer having bumps via the curable resin layer (curable resin film). Then, the curable resin layer after application increases the fluidity by heating, spreads between the bumps so as to cover the bumps, and adheres to the circuit surface, and also reduces the surface of the bump, particularly the surface of the portion near the circuit surface. Cover and embed bumps. The curable resin layer in this state is further cured by heating or irradiation with energy rays to finally form a first protective film, and protects the bumps on the circuit surface in a state of being in close contact with the surface. The semiconductor wafer after the first protective film forming sheet is attached, for example, after the surface opposite to the circuit surface is ground, the first support sheet is removed, and then, by heating the curable resin layer. Then, the burying of the bumps and the formation of the first protective film are performed, and finally, the semiconductor device is incorporated into the semiconductor device with the first protective film provided.
In this specification, the surface of the bump and the circuit surface of the semiconductor wafer may be collectively referred to as a “bump forming surface”.

By using the curable resin film of the present invention, the first protective film sufficiently protects the circuit surface of the semiconductor wafer and the portion of the bump near the circuit surface, that is, the base.
The curable resin film (curable resin layer) of the present invention does not contain chloride ions (Cl ⁻ ) or has a very small content of chloride ions. No chloride ion (Cl ⁻ ) is contained, or the content of chloride ion is significantly reduced. Therefore, by forming the first protective film on the bump formation surface using the curable resin film of the present invention, corrosion of conductive portions such as bumps and circuits on the bump formation surface is suppressed. Further, the protective film on the bump forming surface is usually short-circuited more easily than the protective film on the circuit surface where no bump exists, but by forming the first protective film, short-circuiting may occur even under high temperature and high humidity conditions. Is suppressed. This is because the content of chloride ions in the first protective film is reduced as described above, so that the deposition of the metal constituting the bumps and the wirings can be performed even under high temperature and high humidity conditions. Is assumed to be suppressed.

The easiness of occurrence of short circuit in the protective film such as the first protective film can be determined, for example, by using a semiconductor wafer or a semiconductor chip provided with a protective film on the bump formation surface, by using a highly accelerated life test under high temperature and high humidity conditions ( The evaluation can be made by confirming whether or not a short circuit occurs in the protective film after performing Highly Accelerated Stress Test (HAST).
Further, the easiness of occurrence of a short circuit in the protective film may be determined by a method other than this method, for example, by arranging the protective film in contact with a pair of electrodes, and placing the protective film with electrodes under high temperature and high humidity conditions. It can also be evaluated by applying a voltage to and confirming whether or not a short circuit has occurred in the protective film.
In the present invention, all units of the content “ppm” are based on the mass ratio unless otherwise specified.

  FIG. 1 is a cross-sectional view schematically showing an example of a state in which a first protective film is formed on a bump forming surface using the curable resin film of the present invention. In the drawings used in the following description, in order to facilitate understanding of the features of the present invention, for the sake of convenience, the main portions may be enlarged, and the dimensional ratios and the like of the respective components may be the same as actual ones. Is not always the case.

A plurality of bumps 91 are provided on the circuit surface 90a of the semiconductor wafer 90 shown here. The bump 91 has a shape in which a part of a sphere is cut out by a flat surface, and a flat surface corresponding to the cut and exposed portion is in contact with the circuit surface 90 a of the semiconductor wafer 90.
The first protective film 12 ′ is formed using the curable resin film of the present invention, covers the circuit surface 90 a of the semiconductor wafer 90, and further has a top surface 91 a of the bump 91 and a top surface of the bump 91. A region other than the vicinity is covered. As described above, the first protective film 12 ′ is in close contact with the top surface of the bump 91 and the surface 91 a other than the vicinity thereof and also in close contact with the circuit surface 90 a of the semiconductor wafer 90, and embeds the bump 91.
The substantially spherical shape of the bump 91 as described above is particularly advantageous for forming the first protective film using the curable resin film of the present invention.

In addition, the semiconductor wafer to which the curable resin film of the present invention is used is not limited to the one shown in FIG. 1, and some configurations may be changed, deleted, or added within a range that does not impair the effects of the present invention. May be used. For example, FIG. 1 shows a bump having a substantially spherical shape as described above (a shape in which a part of the sphere is cut off by a plane). In FIG. 1, the shape is elongated in a direction perpendicular to the circuit surface 90 a of the semiconductor wafer 90, that is, the shape of the spheroid which is almost an ellipse (in the major axis direction of the spheroid which is an ellipse). A shape obtained by crushing a bump having a shape including one end cut by a plane) or a substantially spherical shape as described above in the height direction, that is, a substantially spheroidal spheroid (oblate spheroid) A bump having a shape in which a portion including one end in the minor axis direction of a certain spheroid is cut out by a plane) is also exemplified as a bump having a preferable shape. Such a substantially spheroidal bump is also particularly advantageous for forming the first protective film using the curable resin film of the present invention, similarly to the above-mentioned substantially spherical bump.
In addition, the shape of the bump described so far is only an example of a preferable example when the curable resin film of the present invention is applied, and the shape of the bump is not limited to these in the present invention.
Hereinafter, the configuration of the present invention will be described in detail.

The first support sheet may be composed of one layer (single layer) or may be composed of two or more layers. When the support sheet includes a plurality of layers, the constituent materials and thicknesses of the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited as long as the effects of the present invention are not impaired.
In addition, in this specification, not only the case of the first support sheet, but “a plurality of layers may be the same or different from each other” means “all layers may be the same or all layers may be the same. May be different, and only some of the layers may be the same. "Further," the plurality of layers are different from each other "means that at least one of the constituent material and the thickness of each layer is different from each other. "Means.

  Preferred first support sheets include, for example, a laminate in which a first pressure-sensitive adhesive layer is laminated on a first substrate, a first intermediate layer laminated on a first substrate, and a first intermediate layer laminated on the first intermediate layer. One in which one pressure-sensitive adhesive layer is laminated, one in which only the first base material is used, and the like are exemplified.

  Examples of the first protective film forming sheet of the present invention will be described below for each type of the first support sheet with reference to the drawings. In the drawings used in the following description, in order to facilitate understanding of the features of the present invention, for the sake of convenience, the main portions may be enlarged, and the dimensional ratios and the like of the respective components may be the same as actual ones. Is not always the case.

FIG. 2 is a cross-sectional view schematically showing one embodiment of the first protective film forming sheet of the present invention. The first protective film forming sheet 1 shown here uses, as a first support sheet, a sheet in which a first pressure-sensitive adhesive layer is laminated on a first base material. That is, the first protective film forming sheet 1 includes the first adhesive layer 13 on the first base material 11 and the curable resin layer (curable resin film) 12 on the first adhesive layer 13. ,It is configured. The first support sheet 101 is a laminate of the first base material 11 and the first pressure-sensitive adhesive layer 13, and is on one surface 101 a of the first support sheet 101, that is, on one surface 13 a of the first pressure-sensitive adhesive layer 13. Is provided with a curable resin layer 12.
In the first protective film forming sheet 1, the curable resin layer 12 has a reduced chloride ion content, and the cured first protective film also has a chloride ion (Cl ⁻ ) content. Is reduced, and as described above, the chloride ion content of the first protective film is 6 ppm or less with respect to the mass of the first protective film.

FIG. 3 is a cross-sectional view schematically showing another embodiment of the first protective film forming sheet of the present invention. In FIG. 3, the same components as those shown in FIG. 2 are denoted by the same reference numerals as in FIG. 2, and detailed description thereof will be omitted. This is the same in FIGS.
The first protective film forming sheet 2 shown here is a first support sheet in which a first intermediate layer is laminated on a first base material, and a first adhesive layer is laminated on the first intermediate layer. It is a thing using a thing. That is, the first protective film forming sheet 2 includes the first intermediate layer 14 on the first base material 11, the first adhesive layer 13 on the first intermediate layer 14, and the first adhesive layer 13 on the first adhesive layer 13. And a curable resin layer (curable resin film) 12. The first support sheet 102 is a laminate in which the first base material 11, the first intermediate layer 14, and the first pressure-sensitive adhesive layer 13 are laminated in this order, and on one surface 102a of the first support sheet 102, The curable resin layer 12 is provided on one surface 13 a of the first pressure-sensitive adhesive layer 13.
In other words, in the first protective film forming sheet 1 shown in FIG. 2, the first protective film forming sheet 2 is further provided between the first base material 11 and the first pressure-sensitive adhesive layer 13 and further between the first intermediate layer 14 and the first intermediate layer 14. It is provided with.
In the first protective film forming sheet 2, the curable resin layer 12 has a reduced content of chloride ions, and the content of chloride ions in the cured first protective film is as described above. In addition, the content is 6 ppm or less based on the mass of the first protective film.

FIG. 4 is a cross-sectional view schematically showing still another embodiment of the first protective film forming sheet of the present invention.
The first protective film forming sheet 3 shown here uses a sheet made of only the first base material as the first support sheet. That is, the first protective film forming sheet 3 is configured to include the curable resin layer (curable resin film) 12 on the first base material 11. The first support sheet 103 is composed of only the first base material 11, and the curable resin layer 12 is directly formed on one surface 103 a of the first support sheet 103, that is, on one surface 11 a of the first base material 11. It is provided in contact.
In other words, the first protective film forming sheet 3 is obtained by removing the first pressure-sensitive adhesive layer 13 from the first protective film forming sheet 1 shown in FIG.
In the first protective film forming sheet 3, the curable resin layer 12 has a reduced content of chloride ions, and the content of chloride ions in the cured first protective film is as described above. In addition, the content is 6 ppm or less based on the mass of the first protective film.
Next, the configuration of the first support sheet will be described in detail.

-1st base material The 1st base material is a sheet form or a film form, and as a constituent material, various resins are mentioned, for example.
Examples of the resin include polyethylenes such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); and polyethylenes other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin. Polyolefins: ethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylate copolymer, ethylene-norbornene copolymer (ethylene as a monomer) Vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer (resins obtained using vinyl chloride as a monomer); polystyrene; polycycloolefin; polyethylene terephthalate, polyethylene Naphtha Polyesters such as polyesters, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and wholly aromatic polyesters in which all structural units have an aromatic cyclic group; Polyurethane; Polyurethane acrylate; Polyimide; Polyamide; Polycarbonate; Fluororesin; Polyacetal; Modified polyphenylene oxide; Polyphenylene sulfide; Polysulfone;
Examples of the resin include a polymer alloy such as a mixture of the polyester and another resin. The polymer alloy of the polyester and the other resin preferably has a relatively small amount of the resin other than the polyester.
Further, as the resin, for example, a cross-linked resin obtained by cross-linking one or more of the above-listed resins; a modification of an ionomer or the like using one or more of the above-listed resins; Resins are also included.

  In this specification, “(meth) acrylic acid” is a concept including both “acrylic acid” and “methacrylic acid”. The same applies to terms similar to (meth) acrylic acid. For example, “(meth) acrylate” is a concept that includes both “acrylate” and “methacrylate”, and “(meth) acryloyl group” Is a concept including both “acryloyl group” and “methacryloyl group”.

  The resin constituting the first base material may be only one kind, or two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  The first base material may be only one layer (single layer), or may be two or more layers, and in the case of a plurality of layers, these layers may be the same or different from each other. Is not particularly limited.

The thickness of the first base material is preferably 5 to 1000 μm, more preferably 10 to 500 μm, further preferably 15 to 300 μm, and particularly preferably 20 to 150 μm.
Here, the “thickness of the first base material” means the thickness of the entire first base material. For example, the thickness of the first base material having a plurality of layers means all the thicknesses of the first base material. Means the total thickness of the layers.

  It is preferable that the first base material has a high thickness accuracy, that is, a material in which the variation in thickness is suppressed regardless of the position. Among the constituent materials described above, examples of a material that can be used to form the first base material having such high thickness accuracy include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, and ethylene-vinyl acetate copolymer. Coalescence and the like.

  The first base material contains known additives such as a filler, a colorant, an antistatic agent, an antioxidant, an organic lubricant, a catalyst, and a softener (plasticizer), in addition to the main constituent materials such as the resin. It may be.

The first substrate may be transparent or opaque, may be colored according to the purpose, or may have another layer deposited.
When a first pressure-sensitive adhesive layer or a curable resin layer described later has energy ray curability, the first base material preferably transmits energy rays.

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

-First pressure-sensitive adhesive layer The first pressure-sensitive adhesive layer has a sheet shape or a film shape and contains a pressure-sensitive adhesive.
Examples of the adhesive include an acrylic resin (an adhesive made of a resin having a (meth) acryloyl group), a urethane-based resin (an adhesive made of a resin having a urethane bond), and a rubber-based resin (a resin having a rubber structure). Adhesives), silicone resins (adhesives comprising a resin having a siloxane bond), epoxy resins (adhesives comprising a resin having an epoxy group), and adhesive resins such as polyvinyl ether and polycarbonate. Based resins are preferred.

  In the present invention, the "adhesive resin" is a concept that includes both a resin having adhesiveness and a resin having adhesiveness. Resins that exhibit tackiness when used in combination with other components such as additives, and resins that exhibit adhesiveness due to the presence of a trigger such as heat or water are also included.

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

The thickness of the first pressure-sensitive adhesive layer is preferably from 1 to 1000 μm, more preferably from 5 to 500 μm, and particularly preferably from 10 to 100 μm.
Here, “the thickness of the first pressure-sensitive adhesive layer” means the thickness of the entire first pressure-sensitive adhesive layer. For example, the thickness of the first pressure-sensitive adhesive layer including a plurality of layers is the first pressure-sensitive adhesive layer. Means the total thickness of all the layers constituting

The first pressure-sensitive adhesive layer may be formed using an energy-ray-curable pressure-sensitive adhesive, or may be formed using a non-energy-ray-curable pressure-sensitive adhesive. The first pressure-sensitive adhesive layer formed by using the energy ray-curable pressure-sensitive adhesive can easily adjust physical properties before and after curing.
In the present invention, the “energy beam” means an electromagnetic wave or a charged particle beam having an energy quantum, and examples thereof include an ultraviolet ray and an electron beam.
The ultraviolet light can be emitted by using, for example, a high-pressure mercury lamp, a fusion H lamp, a xenon lamp, or the like as an ultraviolet light source. The electron beam can be emitted from an electron beam generated by an electron beam accelerator or the like.
In the present invention, “energy ray-curable” means a property of being cured by irradiation with an energy ray, and “non-energy ray-curable” means a property of not being cured even by irradiation of an energy ray. .

<<< First adhesive composition >>>
The first pressure-sensitive adhesive layer can be formed using a first pressure-sensitive adhesive composition containing a pressure-sensitive adhesive. For example, the first pressure-sensitive adhesive composition is applied to the surface on which the first pressure-sensitive adhesive layer is to be formed and, if necessary, dried, so that the first pressure-sensitive adhesive layer can be formed at a target portion. A more specific method of forming the first pressure-sensitive adhesive layer will be described later in detail together with the method of forming the other layers. In the first pressure-sensitive adhesive composition, the content ratio of components that do not vaporize at room temperature is usually the same as the content ratio of the components in the first pressure-sensitive adhesive layer. In this specification, “normal temperature” means a temperature at which cooling or heating is not particularly performed, that is, a normal temperature, and includes, for example, a temperature of 15 to 25 ° C.

  The application of the first pressure-sensitive adhesive composition may be performed by a known method, for example, an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater, Examples include a method using various coaters such as a screen coater, a Meyer bar coater, and a kiss coater.

  The drying condition of the first pressure-sensitive adhesive composition is not particularly limited. However, when the first pressure-sensitive adhesive composition contains a solvent described below, it is preferable to dry by heating. In this case, for example, 70 to 130 ° C. For 10 seconds to 5 minutes.

  When the first pressure-sensitive adhesive layer is energy-curable, the first pressure-sensitive adhesive composition containing the energy-ray-curable pressure-sensitive adhesive, that is, the energy-ray-curable first pressure-sensitive adhesive composition includes, for example, non-energy First pressure-sensitive adhesive composition containing a radiation-curable pressure-sensitive adhesive resin (I-1a) (hereinafter sometimes abbreviated as “pressure-sensitive resin (I-1a)”) and an energy-ray-curable compound (I-1); an energy ray-curable adhesive resin (I-2a) having an unsaturated group introduced into a side chain of the non-energy ray-curable adhesive resin (I-1a) (hereinafter referred to as "adhesive Resin (I-2a) "), comprising: a first pressure-sensitive adhesive composition (I-2) containing the pressure-sensitive adhesive resin (I-2a) and an energy-ray-curable low-molecular compound. The first pressure-sensitive adhesive composition (I-3) to be contained.

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

[Adhesive resin (I-1a)]
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 structural unit of the acrylic resin may be only one type, or two or more types. When two or more types are used, their combination and ratio can be arbitrarily selected.

Examples of the alkyl (meth) acrylate include those in which the alkyl group constituting the alkyl ester has 1 to 20 carbon atoms, and the alkyl group is linear or branched. Is preferred.
As the alkyl (meth) acrylate, more specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylic acid n-butyl, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) ) Undecyl acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), ( (T) tridecyl acrylate, tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate, Octadecyl (meth) acrylate (stearyl (meth) acrylate), nonadecyl (meth) acrylate, and icosyl (meth) acrylate are exemplified.

  From the viewpoint of improving the adhesive strength of the first adhesive layer, the acrylic polymer preferably has a structural unit derived from an alkyl (meth) acrylate having 4 or more carbon atoms in the alkyl group. The alkyl group preferably has 4 to 12 carbon atoms, and more preferably 4 to 8 carbon atoms, from the viewpoint of further improving the adhesive strength of the first pressure-sensitive adhesive layer. The alkyl (meth) acrylate having 4 or more carbon atoms in the alkyl group is preferably an alkyl acrylate.

It is preferable that the acrylic polymer further has a constituent unit derived from a functional group-containing monomer in addition to the constituent unit derived from the alkyl (meth) acrylate.
As the functional group-containing monomer, for example, the functional group becomes a starting point of crosslinking by reacting with a crosslinking agent described below, or the functional group reacts with the unsaturated group in the unsaturated group-containing compound, Those which can introduce an unsaturated group into the side chain of the acrylic polymer are exemplified.

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

  Examples of the hydroxyl group-containing monomer include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) Hydroxyalkyl (meth) acrylates such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; non- (meth) acrylic resins such as vinyl alcohol and allyl alcohol; And saturated alcohols (unsaturated alcohols having no (meth) acryloyl skeleton).

  Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth) acrylic acid and crotonic acid; fumaric acid, itaconic acid, maleic acid, citracone Ethylenically unsaturated dicarboxylic acids such as acids (dicarboxylic acids having an ethylenically unsaturated bond); anhydrides of the above-mentioned ethylenically unsaturated dicarboxylic acids; and carboxyalkyl (meth) acrylates such as 2-carboxyethyl methacrylate. Can be

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

  The functional group-containing monomer constituting the acrylic polymer may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  In the acrylic polymer, the content of the constituent unit derived from the functional group-containing monomer is preferably from 1 to 35% by mass, more preferably from 3 to 32% by mass, based on the total amount of the constituent unit. , 5 to 30% by mass.

The acrylic polymer may have a constituent unit derived from another monomer in addition to the constituent unit derived from the alkyl (meth) acrylate and the constituent unit derived from the functional group-containing monomer.
The other monomer is not particularly limited as long as it is copolymerizable with an alkyl (meth) acrylate or the like.
Examples of the other monomer include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide and the like.

  The other monomer constituting the acrylic polymer may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

The acrylic polymer can be used as the non-energy radiation curable adhesive resin (I-1a).
On the other hand, when the functional group in the acrylic polymer is reacted with an unsaturated group-containing compound having an energy ray polymerizable unsaturated group (energy ray polymerizable group), the above-mentioned energy ray curable adhesive is used. It can be used as a resin (I-2a).
In the present invention, “energy beam polymerizable” means a property of being polymerized by irradiation with an energy beam.

  The pressure-sensitive adhesive resin (I-1a) contained in the first pressure-sensitive adhesive composition (I-1) may be only one kind, or two or more kinds, and when two or more kinds are used, their combination and ratio are You can choose any.

  In the first pressure-sensitive adhesive composition (I-1), the content of the pressure-sensitive adhesive resin (I-1a) is preferably from 5 to 99% by mass, more preferably from 10 to 95% by mass, and It is particularly preferable that the content be from 90 to 90% by mass.

[Energy ray-curable compound]
Examples of the energy ray-curable compound contained in the first pressure-sensitive adhesive composition (I-1) include a monomer or oligomer having an energy ray-polymerizable unsaturated group and curable by irradiation with energy rays.
Among the energy ray-curable compounds, monomers include, for example, trimethylolpropane tri (meth) acrylate, pentaerythritol (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4 Polybutyl (meth) acrylates such as butylene glycol di (meth) acrylate and 1,6-hexanediol (meth) acrylate; urethane (meth) acrylate; polyester (meth) acrylate; polyether (meth) acrylate; epoxy ( (Meth) acrylate and the like.
Among the energy ray-curable compounds, examples of the oligomer include oligomers obtained by polymerizing the monomers exemplified above.
The energy ray-curable compound is preferably a urethane (meth) acrylate or a urethane (meth) acrylate oligomer in that the molecular weight is relatively large and the storage elastic modulus of the first pressure-sensitive adhesive layer is not easily reduced.

  The energy ray-curable compound contained in the first pressure-sensitive adhesive composition (I-1) may be only one kind, or two or more kinds, and when two or more kinds, the combination and ratio thereof are optional. You can choose.

  In the first pressure-sensitive adhesive composition (I-1), the content of the energy ray-curable compound is preferably from 1 to 95% by mass, more preferably from 5 to 90% by mass, and more preferably from 10 to 90% by mass. Particularly preferred is 85% by mass.

[Crosslinking agent]
When the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the alkyl (meth) acrylate as the pressure-sensitive adhesive resin (I-1a), the first pressure-sensitive adhesive composition The product (I-1) preferably further contains a crosslinking agent.

The cross-linking agent reacts with the functional group to cross-link the adhesive resins (I-1a).
Examples of the crosslinking agent include isocyanate-based crosslinking agents (crosslinking agents having an isocyanate group) such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy-based crosslinking agents such as ethylene glycol glycidyl ether ( A crosslinker having a glycidyl group); an aziridine-based crosslinker such as hexa [1- (2-methyl) -aziridinyl] trifosphatriazine (a crosslinker having an aziridinyl group); a metal chelate-based crosslinker such as aluminum chelate (metal Crosslinking agents having a chelate structure); isocyanurate crosslinking agents (crosslinking agents having an isocyanuric acid skeleton);
The crosslinking agent is preferably an isocyanate-based crosslinking agent in terms of improving the cohesive force of the pressure-sensitive adhesive to improve the pressure-sensitive adhesive strength of the first pressure-sensitive adhesive layer, and being easily available.

  The crosslinking agent contained in the first pressure-sensitive adhesive composition (I-1) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  In the first pressure-sensitive adhesive composition (I-1), the content of the crosslinking agent is 0.01 to 50 parts by mass with respect to 100 parts by mass of the pressure-sensitive resin (I-1a). Preferably, it is more preferably 0.1 to 20 parts by mass, particularly preferably 1 to 10 parts by mass.

[Photopolymerization initiator]
The first pressure-sensitive adhesive composition (I-1) may further contain a photopolymerization initiator. The curing reaction of the first pressure-sensitive adhesive composition (I-1) containing a photopolymerization initiator sufficiently proceeds even when irradiated with a relatively low energy ray 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, benzoin compounds such as benzoin benzoate, benzoin dimethyl ketal, and the like; acetophenone, 2-hydroxy Acetophenone compounds such as -2-methyl-1-phenyl-propan-1-one and 2,2-dimethoxy-1,2-diphenylethan-1-one; bis (2,4,6-trimethylbenzoyl) phenylphosphine Acylphosphine oxide compounds such as oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; sulfidation such as benzylphenyl sulfide and tetramethylthiuram monosulfide Α-ketol compound such as 1-hydroxycyclohexylphenyl ketone; azo compound such as azobisisobutyronitrile; titanocene compound such as titanocene; thioxanthone compound such as thioxanthone; peroxide compound; diketone compound such as diacetyl; Dibenzyl; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone; 2-chloroanthraquinone.
Further, as the photopolymerization initiator, for example, a quinone compound such as 1-chloroanthraquinone; a photosensitizer such as an amine can be used.

  The photopolymerization initiator contained in the first pressure-sensitive adhesive composition (I-1) may be only one kind, two or more kinds, and when two or more kinds, the combination and the ratio thereof can be arbitrarily selected. .

  In the first pressure-sensitive adhesive composition (I-1), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the energy ray-curable compound. , 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass.

[Other additives]
The first pressure-sensitive adhesive composition (I-1) may contain other additives that do not correspond to any of the above-mentioned components, as long as the effects of the present invention are not impaired.
Examples of the other additives include an antistatic agent, an antioxidant, a softener (plasticizer), a filler (filler), a rust inhibitor, a colorant (pigment, dye), a sensitizer, and a tackifier. And known additives such as a reaction retarder and a crosslinking accelerator (catalyst).
In addition, the reaction retarder is, for example, by the action of the catalyst mixed in the first pressure-sensitive adhesive composition (I-1), the purpose of the first pressure-sensitive adhesive composition (I-1) during storage is This prevents the progress of a crosslinking reaction that does not occur. Examples of the reaction retarder include those which form a chelate complex by chelation with a catalyst, and more specifically, those having two or more carbonyl groups (-C (= O)-) in one molecule. No.

  The other additives contained in the first pressure-sensitive adhesive composition (I-1) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

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

[solvent]
The first pressure-sensitive adhesive composition (I-1) may contain a solvent. Since the first pressure-sensitive adhesive composition (I-1) contains a solvent, the suitability for coating on the surface to be coated is improved.

  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 (carboxylic acid esters); ethers such as tetrahydrofuran and dioxane; cyclohexane and n-hexane. Aliphatic hydrocarbons; aromatic hydrocarbons such as toluene and xylene; and alcohols such as 1-propanol and 2-propanol.

  As the solvent, for example, the solvent used in the production of the adhesive resin (I-1a) is not removed from the adhesive resin (I-1a), and is used as it is in the first adhesive composition (I-1). Alternatively, a solvent of the same or different type as that used in the production of the pressure-sensitive adhesive resin (I-1a) may be separately added during the production of the first pressure-sensitive adhesive composition (I-1).

  The solvent contained in the first pressure-sensitive adhesive composition (I-1) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

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

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

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

The unsaturated group-containing compound can bond to the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a) in addition to the energy ray polymerizable unsaturated group. It is a compound having a group.
Examples of the energy ray polymerizable unsaturated group include a (meth) acryloyl group, a vinyl group (ethenyl group), an allyl group (2-propenyl group) and the like, and a (meth) acryloyl group is preferable.
Examples of the group capable of binding to the functional group in the adhesive resin (I-1a) include an isocyanate group and a glycidyl group capable of binding to a hydroxyl group or an amino group, and a hydroxyl group and amino group capable of binding to a carboxy group or an epoxy group. And the like.

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

  The pressure-sensitive adhesive resin (I-2a) contained in the first pressure-sensitive adhesive composition (I-2) may be only one kind, or two or more kinds, and when two or more kinds are used, their combination and ratio are You can choose any.

  In the first pressure-sensitive adhesive composition (I-2), the content of the pressure-sensitive adhesive resin (I-2a) is preferably from 5 to 99% by mass, more preferably from 10 to 95% by mass, and more preferably from 10 to 95% by mass. It is particularly preferable that the content be from 90 to 90% by mass.

[Crosslinking agent]
When the acrylic polymer having a structural unit derived from a functional group-containing monomer similar to that in the adhesive resin (I-1a) is used as the adhesive resin (I-2a), for example, the first adhesive composition Product (I-2) may further contain a crosslinking agent.

As the crosslinking agent in the first pressure-sensitive adhesive composition (I-2), the same crosslinking agent as in the first pressure-sensitive adhesive composition (I-1) can be used.
The crosslinking agent contained in the first pressure-sensitive adhesive composition (I-2) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  In the first pressure-sensitive adhesive composition (I-2), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass with respect to 100 parts by mass of the pressure-sensitive resin (I-2a). Preferably, it is more preferably 0.1 to 20 parts by mass, particularly preferably 1 to 10 parts by mass.

[Photopolymerization initiator]
The first pressure-sensitive adhesive composition (I-2) may further contain a photopolymerization initiator. The curing reaction of the first pressure-sensitive adhesive composition (I-2) containing a photopolymerization initiator sufficiently proceeds even when irradiated with a relatively low energy ray such as ultraviolet rays.

As the photopolymerization initiator in the first pressure-sensitive adhesive composition (I-2), the same photopolymerization initiator as in the first pressure-sensitive adhesive composition (I-1) can be used.
The photopolymerization initiator contained in the first pressure-sensitive adhesive composition (I-2) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

  In the first pressure-sensitive adhesive composition (I-2), the content of the photopolymerization initiator is 0.01 to 20 parts by mass based on 100 parts by mass of the pressure-sensitive resin (I-2a). Is preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass.

[Other additives]
The first pressure-sensitive adhesive composition (I-2) may contain other additives that do not correspond to any of the above-mentioned components, as long as the effects of the present invention are not impaired.
Examples of the other additives in the first pressure-sensitive adhesive composition (I-2) include the same as the other additives in the first pressure-sensitive adhesive composition (I-1).
The other additives contained in the first pressure-sensitive adhesive composition (I-2) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

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

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

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

  In the first pressure-sensitive adhesive composition (I-3), the content of the pressure-sensitive adhesive resin (I-2a) is preferably from 5 to 99% by mass, more preferably from 10 to 95% by mass, and It is particularly preferable that the content be from 90 to 90% by mass.

[Energy beam-curable low molecular weight compound]
Examples of the energy ray-curable low molecular weight compound contained in the first pressure-sensitive adhesive composition (I-3) include monomers and oligomers having an energy ray-polymerizable unsaturated group and curable by irradiation with energy rays. And the same energy ray-curable compound contained in the first pressure-sensitive adhesive composition (I-1).
The energy ray-curable low molecular weight compound contained in the first pressure-sensitive adhesive composition (I-3) may be only one kind, or two or more kinds, and when two or more kinds are used, their combination and ratio are You can choose any.

  In the first pressure-sensitive adhesive composition (I-3), the content of the energy ray-curable low molecular weight compound is 0.01 to 300 with respect to 100 parts by mass of the pressure-sensitive resin (I-2a). It is preferable that it is a mass part, it is more preferable that it is 0.03-200 mass parts, and it is especially preferable that it is 0.05-100 mass parts.

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

Examples of the photopolymerization initiator in the first pressure-sensitive adhesive composition (I-3) include the same as the photopolymerization initiator in the first pressure-sensitive adhesive composition (I-1).
The photopolymerization initiator contained in the first pressure-sensitive adhesive composition (I-3) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

  In the first pressure-sensitive adhesive composition (I-3), the content of the photopolymerization initiator was determined based on the total content of the pressure-sensitive adhesive resin (I-2a) and the energy ray-curable low-molecular compound of 100 parts by mass. The amount is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass.

[Other additives]
The first pressure-sensitive adhesive composition (I-3) may contain other additives that do not correspond to any of the above-mentioned components, as long as the effects of the present invention are not impaired.
Examples of the other additives include the same as the other additives in the first pressure-sensitive adhesive composition (I-1).
The other additives contained in the first pressure-sensitive adhesive composition (I-3) may be only one kind, two or more kinds, and when two or more kinds, the combination and the ratio thereof can be arbitrarily selected. .

  In the first pressure-sensitive adhesive composition (I-3), the content of the other additives is not particularly limited, and may be appropriately selected depending on the type.

[solvent]
The first pressure-sensitive adhesive composition (I-3) may contain a solvent for the same purpose as in the case of the first pressure-sensitive adhesive composition (I-1).
Examples of the solvent in the first pressure-sensitive adhesive composition (I-3) include the same solvents as those in the first pressure-sensitive adhesive composition (I-1).
The solvent contained in the first pressure-sensitive adhesive composition (I-3) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.
In the first pressure-sensitive adhesive composition (I-3), the content of the solvent is not particularly limited, and may be appropriately adjusted.

<First pressure-sensitive adhesive composition other than first pressure-sensitive adhesive compositions (I-1) to (I-3)>
So far, the first pressure-sensitive adhesive composition (I-1), the first pressure-sensitive adhesive composition (I-2), and the first pressure-sensitive adhesive composition (I-3) have been mainly described. Described as a general first pressure-sensitive adhesive composition other than these three first pressure-sensitive adhesive compositions (in the present specification, "first pressure-sensitive adhesive compositions (I-1) to (I- The first pressure-sensitive adhesive composition other than 3) may be used in the same manner.

As the first pressure-sensitive adhesive composition other than the first pressure-sensitive adhesive compositions (I-1) to (I-3), in addition to the energy-ray-curable pressure-sensitive adhesive composition, a non-energy-ray-curable pressure-sensitive adhesive composition Are also mentioned.
Examples of the non-energy radiation curable pressure-sensitive adhesive composition include an acrylic resin (a resin having a (meth) acryloyl group), a urethane resin (a resin having a urethane bond), and a rubber resin (a resin having a rubber structure). And a resin containing an adhesive resin such as a silicone resin (a resin having a siloxane bond), an epoxy resin (a resin having an epoxy group), polyvinyl ether, or polycarbonate, and a resin containing an acrylic resin is preferable. .

  The first pressure-sensitive adhesive composition other than the first pressure-sensitive adhesive compositions (I-1) to (I-3) preferably contains one or more crosslinking agents, and the content thereof is as described above. It can be the same as in the case of the first pressure-sensitive adhesive composition (I-1) and the like.

<<< Production method of first pressure-sensitive adhesive composition >>
The first pressure-sensitive adhesive composition such as the first pressure-sensitive adhesive compositions (I-1) to (I-3) includes a first pressure-sensitive adhesive such as the pressure-sensitive adhesive and, if necessary, a component other than the pressure-sensitive adhesive. It is obtained by blending each component for constituting the composition.
The order of addition of each component 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 of the components other than the solvent, and may be used by previously diluting the components, or may be used by diluting any of the components other than the solvent in advance. Alternatively, a solvent may be used by mixing with these components.
The method of mixing each component at the time of blending is not particularly limited, and a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by adding ultrasonic waves, and the like. What is necessary is just to select suitably.
The temperature and time at the time of addition and mixing of each component are not particularly limited as long as each component is not deteriorated, and may be appropriately adjusted, but the temperature is preferably 15 to 30 ° C.

-1st intermediate | middle layer The said 1st intermediate | middle layer is a sheet form or a film form, The constituent material should just be suitably selected according to the objective, and is not specifically limited.
For example, in the case where the protection film covering the semiconductor surface is intended to suppress the deformation of the protection film by reflecting the shape of the bumps existing on the semiconductor surface, a preferable constituent material of the first intermediate layer Examples thereof include urethane (meth) acrylate and the like from the viewpoint of further improving the sticking property of the first intermediate layer.

  The first intermediate layer may be only one layer (single layer) or two or more layers. When the first intermediate layer is a plurality of layers, the plurality of layers may be the same or different from each other. Is not particularly limited.

The thickness of the first intermediate layer can be appropriately adjusted according to the height of the bump on the semiconductor surface to be protected. However, the thickness is 5 to 600 μm because the influence of the bump having a relatively high height can be easily absorbed. The thickness is more preferably 5 to 500 μm, and particularly preferably 5 to 400 μm.
Here, the “thickness of the first intermediate layer” means the thickness of the entire first intermediate layer. For example, the thickness of the first intermediate layer including a plurality of layers means all of the thicknesses of the first intermediate layer. Means the total thickness of the layers.

<<< First intermediate layer forming composition >>>
The first intermediate layer can be formed using the first intermediate layer forming composition containing the constituent material. For example, the first intermediate layer forming composition is applied to the surface on which the first intermediate layer is to be formed, and then dried or cured by irradiation with energy rays as necessary, so that the first intermediate layer is applied to the target portion. Layers can be formed. A more specific method of forming the first intermediate layer will be described later in detail together with the method of forming the other layers. In the composition for forming the first intermediate layer, the content ratio of the components that do not vaporize at room temperature is usually the same as the content ratio of the components in the first intermediate layer. Here, “normal temperature” is as described above.

  The application of the composition for forming the first intermediate layer may be performed by a known method, for example, an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife Examples thereof include a method using various coaters such as a coater, a screen coater, a Meyer bar coater, and a kiss coater.

The drying conditions of the first intermediate layer forming composition are not particularly limited. However, when the first intermediate layer forming composition contains a solvent described below, it is preferable to dry by heating. In this case, for example, It is preferable to dry at 70 to 130 ° C. for 10 seconds to 5 minutes.
When the composition for forming the first intermediate layer has energy ray curability, it is preferable that the composition is dried and further cured by irradiation with energy rays.

  Examples of the first intermediate layer forming composition include a first intermediate layer forming composition (II-1) containing urethane (meth) acrylate.

<First intermediate layer forming composition (II-1)>
The first intermediate layer forming composition (II-1) contains urethane (meth) acrylate as described above.

[Urethane (meth) acrylate]
Urethane (meth) acrylate is a compound having at least a (meth) acryloyl group and a urethane bond in one molecule, and has energy ray polymerizability.
The urethane (meth) acrylate may be a monofunctional one (having only one (meth) acryloyl group in one molecule) or a bifunctional or higher functional (the (meth) acryloyl group in one molecule) ), That is, polyfunctional ones, but it is preferable to use at least monofunctional ones.

  The urethane (meth) acrylate contained in the first intermediate layer-forming composition includes, for example, a hydroxyl group and a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound and a polyvalent isocyanate compound. Examples thereof include those obtained by reacting a (meth) acrylic compound having a (meth) acryloyl group. Here, the “terminal isocyanate urethane prepolymer” means a prepolymer having a urethane bond and having an isocyanate group at the terminal of the molecule.

  The urethane (meth) acrylate contained in the first intermediate layer-forming composition (II-1) may be only one kind, or two or more kinds, and when two or more kinds, the combination and ratio thereof are arbitrary. Can be selected.

(Polyol compound)
The polyol compound is not particularly limited as long as it is a compound having two or more hydroxyl groups in one molecule.
One of the polyol compounds may be used alone, or two or more may be used in combination. When two or more are used in combination, their combination and ratio can be arbitrarily selected.

Examples of the polyol compound include an alkylene diol, a polyether type polyol, a polyester type polyol, and a polycarbonate type polyol.
The polyol compound may be any of a difunctional diol, a trifunctional triol, and a tetrafunctional or higher polyol, but a diol is preferred because it is easily available and has excellent versatility and reactivity. .

-Polyether polyol The polyether polyol is not particularly limited, but is preferably a polyether diol. Examples of the polyether diol include compounds represented by the following general formula (1). Can be

（式中、ｎは２以上の整数であり；Ｒは２価の炭化水素基であり、複数個のＲは互いに同一であっても異なっていてもよい。）

(In the formula, n is an integer of 2 or more; R is a divalent hydrocarbon group, and a plurality of Rs may be the same or different.)

  In the formula, n represents the number of repeating units of the group represented by the general formula “—RO—”, and is not particularly limited as long as it is an integer of 2 or more. Among them, n is preferably from 10 to 250, more preferably from 25 to 205, and particularly preferably from 40 to 185.

  In the formula, R is not particularly limited as long as it is a divalent hydrocarbon group, but is preferably an alkylene group, more preferably an alkylene group having 1 to 6 carbon atoms, and ethylene, propylene or tetra It is more preferably a methylene group, particularly preferably a propylene group or a tetramethylene group.

  The compound represented by the formula (1) is preferably polyethylene glycol, polypropylene glycol or polytetramethylene glycol, more preferably polypropylene glycol or polytetramethylene glycol.

  By reacting the polyether-type diol with the polyvalent isocyanate compound, a product having an ether bond represented by the following general formula (1a) is obtained as the terminal isocyanate urethane prepolymer. Then, by using such an isocyanate-terminated urethane prepolymer, the urethane (meth) acrylate has a structure having the ether bond, that is, a structure having a structural unit derived from the polyether diol. .

（式中、Ｒ及びｎは前記と同じである。）

(In the formula, R and n are the same as described above.)

-Polyester type polyol The polyester type polyol is not particularly limited, and examples thereof include those obtained by performing an esterification reaction using a polybasic acid or a derivative thereof. In this specification, the term "derivative" means a compound obtained by substituting one or more groups of an original compound with other groups (substituents), unless otherwise specified. Here, the “group” includes not only an atomic group formed by bonding a plurality of atoms but also one atom.

Examples of the polybasic acids and derivatives thereof include polybasic acids and derivatives thereof which are generally used as a raw material for producing polyester.
Examples of the polybasic acid include a saturated aliphatic polybasic acid, an unsaturated aliphatic polybasic acid, an aromatic polybasic acid, and the like, and a dimer acid corresponding to any of these may be used.

Examples of the saturated aliphatic polybasic acids include saturated aliphatic dibasic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. .
Examples of the unsaturated aliphatic polybasic acids include unsaturated aliphatic dibasic acids such as maleic acid and fumaric acid.
Examples of the aromatic polybasic acid include aromatic dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid and 2,6-naphthalenedicarboxylic acid; aromatic tribasic acids such as trimellitic acid; And the like.

  Examples of the derivatives of the polybasic acids include the above-mentioned saturated aliphatic polybasic acids, acid anhydrides of unsaturated aliphatic polybasic acids and aromatic polybasic acids, and hydrogenated dimer acids.

  One of the polybasic acids or derivatives thereof may be used alone, or two or more may be used in combination. When two or more are used in combination, their combination and ratio can be arbitrarily selected. .

  The polybasic acid is preferably an aromatic polybasic acid in that it is suitable for forming a coating film having an appropriate hardness.

In the esterification reaction for obtaining the polyester type polyol, a known catalyst may be used as necessary.
Examples of the catalyst include tin compounds such as dibutyltin oxide and stannous octylate; and alkoxy titanium such as tetrabutyl titanate and tetrapropyl titanate.

-Polycarbonate-type polyol The polycarbonate-type polyol is not particularly limited, and examples thereof include those obtained by reacting the same glycol as the compound represented by the formula (1) with an alkylene carbonate.
Here, any one of glycol and alkylene carbonate may be used alone, or two or more may be used in combination. When two or more are used in combination, their combination and ratio can be arbitrarily selected. .

The number average molecular weight calculated from the hydroxyl value of the polyol compound is preferably from 1,000 to 10,000, more preferably from 2,000 to 9000, and particularly preferably from 3,000 to 7000. When the number average molecular weight is 1000 or more, excessive generation of urethane bonds is suppressed, and control of the viscoelastic properties of the first intermediate layer becomes easier. Moreover, when the number average molecular weight is 10,000 or less, excessive softening of the first intermediate layer is suppressed.
The number average molecular weight calculated from the hydroxyl value of the polyol compound is a value calculated from the following equation.
[Number average molecular weight of polyol compound] = [number of functional groups of polyol compound] × 56.11 × 1000 / [hydroxyl value of polyol compound (unit: mgKOH / g)]

  The polyol compound is preferably a polyether type polyol, and more preferably a polyether type diol.

(Polyvalent isocyanate compound)
The polyvalent isocyanate compound to be reacted with the polyol compound is not particularly limited as long as it has two or more isocyanate groups.
As the polyvalent isocyanate compound, one type may be used alone, or two or more types may be used in combination. When two or more types are used in combination, their combination and ratio can be arbitrarily selected.

Examples of the polyvalent isocyanate compound include linear aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate; isophorone diisocyanate, norbornane diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, and dicyclohexylmethane-2. 4,4'-diisocyanate, cycloaliphatic diisocyanate such as ω, ω'-diisocyanate dimethylcyclohexane; 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tolidine diisocyanate, tetramethylene xylylene diisocyanate, naphthalene-1, And aromatic diisocyanates such as 5-diisocyanate.
Among these, the polyvalent isocyanate compound is preferably isophorone diisocyanate, hexamethylene diisocyanate or xylylene diisocyanate from the viewpoint of handling properties.

((Meth) acrylic compound)
The (meth) acrylic compound to be reacted with the terminal isocyanate urethane prepolymer is not particularly limited as long as the compound has at least a hydroxyl group and a (meth) acryloyl group in one molecule.
The (meth) acrylic compounds may be used alone or in combination of two or more. When two or more are used in combination, their combination and ratio can be arbitrarily selected.

Examples of the (meth) acrylic compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxy (meth) acrylate. Butyl, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 5-hydroxycyclooctyl (meth) acrylate, 2- (meth) acrylate Hydroxy group-containing (meth) acrylates such as hydroxy-3-phenyloxypropyl, pentaerythritol tri (meth) acrylate, polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate; N-methylol (meth) acrylamide Hydroxyl group-containing (meth) acrylamide and the like; vinyl alcohol, vinyl phenol or bisphenol A diglycidyl ether (meth) reaction products obtained by reacting acrylic acid.
Among these, the (meth) acrylic compound is preferably a hydroxyl group-containing (meth) acrylic acid ester, more preferably a hydroxyl group-containing (meth) acrylic acid alkyl ester, and (meth) acrylic acid 2- Particularly preferred is hydroxyethyl.

  The reaction between the terminal isocyanate urethane prepolymer and the (meth) acrylic compound may be performed using a solvent, a catalyst, or the like, if necessary.

  Conditions for reacting the terminal isocyanate urethane prepolymer with the (meth) acrylic compound may be appropriately adjusted. For example, the reaction temperature is preferably from 60 to 100 ° C., and the reaction time is from 1 to 1. Preferably, it is 4 hours.

The urethane (meth) acrylate may be any of an oligomer, a polymer, and a mixture of an oligomer and a polymer, but is preferably an oligomer.
For example, the urethane (meth) acrylate preferably has a weight average molecular weight of 1,000 to 100,000, more preferably 3,000 to 80,000, and particularly preferably 5,000 to 65,000. When the weight average molecular weight is 1000 or more, in the polymer of urethane (meth) acrylate and a polymerizable monomer described below, the first intermediate is generated due to the intermolecular force between the urethane (meth) acrylate-derived structures. It is easy to optimize the hardness of the layer.
In the present specification, the weight average molecular weight is a value in terms of polystyrene measured by a gel permeation chromatography (GPC) method unless otherwise specified.

[Polymerizable monomer]
The first intermediate layer forming composition (II-1) may contain a polymerizable monomer in addition to the urethane (meth) acrylate from the viewpoint of further improving the film forming property.
The polymerizable monomer is a compound having energy ray polymerizability and excluding oligomers and polymers having a weight average molecular weight of 1,000 or more, and having at least one (meth) acryloyl group in one molecule. Is preferred.

  Examples of the polymerizable monomer include (meth) acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester is a chain having 1 to 30 carbon atoms; a hydroxyl group, an amide group, an amino group, an epoxy group, or the like. Functional group-containing (meth) acrylic compound having a functional group of (meth) acrylic acid ester having an aliphatic cyclic group; (meth) acrylic acid ester having an aromatic hydrocarbon group; having a heterocyclic group ( (Meth) acrylic acid esters; compounds having a vinyl group; compounds having an allyl group.

  Examples of the alkyl (meth) acrylate having a chain alkyl group having 1 to 30 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and ( Isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, (meth) Hexyl acrylate, heptyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, (meth) acrylic acid Isononyl, decyl (meth) acrylate, undecyl (meth) acrylate, dode (meth) acrylate (Lauryl (meth) acrylate), tridecyl (meth) acrylate, tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate ((meth)) Palmityl acrylate), heptadecyl (meth) acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate), isooctadecyl (meth) acrylate (isostearyl (meth) acrylate), nonadecyl (meth) acrylate And icosyl (meth) acrylate.

  Examples of the functional group-containing (meth) acrylic acid derivative include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) acrylic acid. Hydroxyl-containing (meth) acrylates such as 2-hydroxybutyl, 3-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, (Meth) acrylamides such as N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide and the like Derivatives having an amino group (meth ) Acrylates (hereinafter sometimes referred to as “amino group-containing (meth) acrylates”) having a monosubstituted amino group in which one hydrogen atom of an amino group is substituted with a group other than a hydrogen atom (Meth) acrylic acid ester (hereinafter sometimes referred to as "monosubstituted amino group-containing (meth) acrylic acid ester"); disubstitution in which two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom (Meth) acrylic acid ester having an amino group (hereinafter, may be referred to as "(2-) substituted amino group-containing (meth) acrylic acid ester"); epoxy such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate (Meth) acrylic acid ester having a group (hereinafter, may be referred to as “epoxy group-containing (meth) acrylic acid ester”).

Here, “amino group-containing (meth) acrylate” means a compound in which one or two or more hydrogen atoms of (meth) acrylate are substituted with an amino group (—NH ₂ ). . Similarly, “monosubstituted amino group-containing (meth) acrylate” means a compound in which one or more hydrogen atoms of (meth) acrylate are substituted with monosubstituted amino groups, “Disubstituted amino group-containing (meth) acrylate” means a compound obtained by substituting one or more hydrogen atoms of (meth) acrylate with a disubstituted amino group.
In the “monosubstituted amino group” and the “disubstituted amino group”, examples of the group other than the hydrogen atom to be substituted with a hydrogen atom (that is, a substituent) include an alkyl group.

  Examples of the (meth) acrylate having an aliphatic cyclic group include, for example, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and (meth) acrylic acid. Dicyclopentenyloxyethyl, cyclohexyl (meth) acrylate, adamantyl (meth) acrylate and the like.

  Examples of the (meth) acrylate having an aromatic hydrocarbon group include phenylhydroxypropyl (meth) acrylate, benzyl (meth) acrylate, and 2-hydroxy-3-phenoxypropyl (meth) acrylate. No.

The heterocyclic group in the (meth) acrylate having a heterocyclic group may be any of an aromatic heterocyclic group and an aliphatic heterocyclic group.
Examples of the (meth) acrylate having a heterocyclic group include tetrahydrofurfuryl (meth) acrylate and (meth) acryloylmorpholine.

  Examples of the compound having a vinyl group include styrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, N-vinylformamide, N-vinylpyrrolidone, and N-vinylcaprolactam.

  Examples of the compound having an allyl group include allyl glycidyl ether.

  The polymerizable monomer preferably has a relatively bulky group from the viewpoint of good compatibility with the urethane (meth) acrylate, and such a polymerizable monomer has an aliphatic cyclic group (meth ) Acrylates, (meth) acrylates having an aromatic hydrocarbon group, and (meth) acrylates having a heterocyclic group, and (meth) acrylates having an aliphatic cyclic group are more preferable. preferable.

  The polymerizable monomer contained in the first intermediate layer forming composition (II-1) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof are arbitrarily selected. it can.

  In the first intermediate layer forming composition (II-1), the content of the polymerizable monomer is preferably from 10 to 99% by mass, more preferably from 15 to 95% by mass, and more preferably from 20 to 90% by mass. %, More preferably 25 to 80% by mass.

[Photopolymerization initiator]
The first intermediate layer forming composition (II-1) may contain a photopolymerization initiator in addition to the urethane (meth) acrylate and the polymerizable monomer. The curing reaction of the first intermediate layer-forming composition (II-1) containing a photopolymerization initiator sufficiently proceeds even when irradiated with relatively low energy rays such as ultraviolet rays.

  As the photopolymerization initiator in the first intermediate layer forming composition (II-1), the same photopolymerization initiator as in the first pressure-sensitive adhesive composition (I-1) can be used.

  The photopolymerization initiator contained in the first intermediate layer forming composition (II-1) may be only one kind, or two or more kinds, and when two or more kinds, the combination and ratio thereof are optional. You can choose.

  In the first intermediate layer forming composition (II-1), the content of the photopolymerization initiator is 0.01 to 20 with respect to 100 parts by mass of the total content of the urethane (meth) acrylate and the polymerizable monomer. It is preferable that it is mass part, it is more preferable that it is 0.03-10 mass parts, and it is especially preferable that it is 0.05-5 mass parts.

[Resin components other than urethane (meth) acrylate]
The first intermediate layer forming composition (II-1) may contain a resin component other than the urethane (meth) acrylate as long as the effects of the present invention are not impaired.
The type of the resin component and its content in the first intermediate layer forming composition (II-1) may be appropriately selected depending on the purpose, and are not particularly limited.

[Other additives]
The first intermediate layer-forming composition (II-1) may contain other additives that do not correspond to any of the above-mentioned components as long as the effects of the present invention are not impaired.
Examples of the other additives include known agents such as a crosslinking agent, an antistatic agent, an antioxidant, a chain transfer agent, a softening agent (plasticizer), a filler, a rust inhibitor, and a coloring agent (pigment, dye). Additives may be mentioned.
For example, the chain transfer agent includes a thiol compound having at least one thiol group (mercapto group) in one molecule.

  Examples of the thiol compound include nonylmercaptan, 1-dodecanethiol, 1,2-ethanedithiol, 1,3-propanedithiol, triazinethiol, triazinedithiol, triazinetrithiol, 1,2,3-propanetrithiol, Tetraethylene glycol-bis (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakisthioglucolate, dipentaerythritol hexa Kis (3-mercaptopropionate), tris [(3-mercaptopropionyloxy) -ethyl] -isocyanurate, 1,4-bis (3-mercaptobutyryloxy) butane, penta Risritol tetrakis (3-mercaptobutyrate), 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione And the like.

  The other additive contained in the first intermediate layer forming composition (II-1) may be only one kind, or two or more kinds, and when two or more kinds, the combination and ratio thereof are optional. You can choose.

  In the first intermediate layer forming composition (II-1), the content of other additives is not particularly limited, and may be appropriately selected according to the type.

[solvent]
The first intermediate layer forming composition (II-1) may contain a solvent. Since the first intermediate layer forming composition (II-1) contains a solvent, the suitability for coating on the surface to be coated is improved.

<< Production method of first intermediate layer forming composition >>
The first intermediate layer-forming composition such as the first intermediate layer-forming composition (II-1) is obtained by blending each component for constituting the first intermediate layer-forming composition.
The order of addition of each component 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 of the components other than the solvent, and may be used by previously diluting the components, or may be used by diluting any of the components other than the solvent in advance. Alternatively, a solvent may be used by mixing with these components.
The method of mixing each component at the time of blending is not particularly limited, and a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by adding ultrasonic waves, and the like. What is necessary is just to select suitably.
The temperature and time at the time of addition and mixing of each component are not particularly limited as long as each component is not deteriorated, and may be appropriately adjusted, but the temperature is preferably 15 to 30 ° C.

◎ Curable Resin Layer The curable resin layer (curable resin film) is a layer for protecting the circuit surface of the semiconductor wafer and the bumps provided on the circuit surface, and includes a thermosetting resin layer (thermosetting resin layer). Curable resin film) or an energy ray-curable resin layer (energy ray-curable resin film). The curable resin layer forms a first protective film by curing.

  In the present invention, the curable resin layer is cured to form a cured product, and under conditions of 125 ° C. and 20 hours, chloride ions are extracted from the cured product with hot water. When the concentration is measured, the content of chloride ions in the cured product is 6 ppm or less based on the mass of the cured product. That is, the first protective film, which is a cured product of the curable resin layer, is obtained by measuring the concentration of chloride ions in the extracted water by the above-described hot water extraction method and using the measured value. Has a chloride ion content of 6 ppm or less. When the chloride ion content of the first protective film is equal to or less than the upper limit, not only corrosion of conductive portions such as bumps and circuits on the bump formation surface is suppressed, but also under high temperature and high humidity conditions. Even with this, occurrence of a short circuit in the first protective film is suppressed. In this specification, the “content of chloride ions in the first protective film (cured product)” means the content obtained by using the above-described hot water extraction method, unless otherwise specified. .

From the viewpoint that the above-mentioned effects of the present invention can be more remarkably obtained, the chloride ion content of the first protective film is preferably 5 ppm or less, for example, 3 ppm or less, 1 ppm or less. is there.
The lower limit of the chloride ion content of the first protective film is not particularly limited, and may be 0 ppm (that is, lower than the detection limit).

In the hot water extraction of chloride ions from various samples such as the first protective film (the cured product of the curable resin layer), for example, a sample and 20 mL of distilled water per 1 g of the sample are sealed in a container. , 125 ° C. for 20 hours, and after cooling, obtaining extracted water from which the solid content has been removed from the obtained heat-treated product.
The container may be made of any material as long as its constituent material does not contain chlorine atoms and has heat resistance.
As a method of obtaining an extraction water by removing the solid content from the heat-treated product, for example, a method of leaving the heat-treated product to stand, and then obtaining a supernatant after sedimentation of the solid content, subjecting the heat-treated product to centrifugation, A method of obtaining a supernatant after sedimentation of a solid content, a method of removing a solid content by filtering a heat-treated substance with a filter, and a method of obtaining a filtrate, etc., and any one of the above supernatants is further filtered with a filter to obtain a filtrate May be obtained.

The chloride ion concentration of the obtained extraction water can be measured by a known method such as ion chromatography.
If the chloride ion concentration of the extraction water is determined, the chloride ion content of the sample is determined from the amount of the sample used in the hot water extraction.

  In the present invention, the content of chloride ions in the first protective film can be adjusted by the content of chloride ions in the curable resin layer. On the other hand, the curable resin layer can be formed by using a curable resin layer forming composition containing the constituent material. Therefore, the content of chloride ions in the curable resin layer can be adjusted, for example, by using a reduced content of chloride ions as a component of the composition for forming a curable resin layer, and It can also be adjusted by performing a treatment for removing chloride ions from the composition for forming a curable resin layer. The method for producing the curable resin layer forming composition (thermosetting resin layer forming composition, energy ray-curable resin layer forming composition) will be described in detail later.

The chloride ions contained in the curable resin layer and the cured product are derived, for example, from impurities of the components contained in the composition for forming a curable resin layer. For example, it is known that an epoxy resin (B1) described later easily contains chloride ions as impurities due to its manufacturing method.
On the other hand, the curable resin layer and the cured product may also contain anions other than chloride ions. Examples of such anions include fluoride ions (F ⁻ ) and sulfate ions (SO ₄ ²⁻ ). However, usually, the content of anions other than chloride ions in the curable resin layer and the cured product is significantly smaller than the content of chloride ions. Therefore, usually, in order to reduce the short circuit in the first protective film, the content of chloride ions may be reduced.

○ Thermosetting resin layer Preferred examples of the thermosetting resin layer include those containing a polymer component (A) and a thermosetting component (B). The polymer component (A) is a component that can be regarded as formed by a polymerization reaction of the polymerizable compound. The thermosetting component (B) is a component that can be cured (polymerized) by using heat as a trigger of the reaction. In the present invention, the polymerization reaction includes a polycondensation reaction.

  The thermosetting resin layer may be only one layer (single layer), or may be two or more layers, and in the case of a plurality of layers, these layers may be the same or different from each other. Is not particularly limited.

The thickness of the thermosetting resin layer is preferably from 1 to 100 μm, more preferably from 5 to 75 μm, and particularly preferably from 5 to 50 μm. When the thickness of the thermosetting resin layer is equal to or larger than the lower limit, the first protective film having higher protection ability can be formed. Further, when the thickness of the thermosetting resin layer is equal to or less than the upper limit, an excessive thickness is suppressed.
Here, the “thickness of the thermosetting resin layer” means the thickness of the entire thermosetting resin layer. For example, the thickness of the thermosetting resin layer composed of a plurality of layers refers to the thickness of the thermosetting resin layer. Means the total thickness of all the layers constituting

The thermosetting resin layer is adhered to the bump forming surface of the semiconductor wafer and cured to form a first protective film. The curing condition is such that the first protective film sufficiently exhibits its function. It is not particularly limited as long as it is satisfied, and may be appropriately selected according to the type of the thermosetting resin layer.
For example, the heating temperature at the time of curing the thermosetting resin layer is preferably 140 to 180 ° C. The heating time during the curing is preferably 50 minutes to 2 hours.

<< thermosetting resin layer forming composition >>
The thermosetting resin layer can be formed by using a thermosetting resin layer forming composition containing the constituent material. For example, a thermosetting resin layer-forming composition is applied to the surface on which the thermosetting resin layer is to be formed, and dried if necessary, whereby the thermosetting resin layer can be formed at a target portion. In the composition for forming a thermosetting resin layer, the content ratio of components that do not vaporize at room temperature is usually the same as the content ratio of the components in the thermosetting resin layer. Here, “normal temperature” is as described above.

  The coating of the composition for forming a thermosetting resin layer may be performed by a known method, for example, an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, Examples thereof include a method using various coaters such as a knife coater, a screen coater, a Meyer bar coater, and a kiss coater.

  The drying conditions of the composition for forming a thermosetting resin layer are not particularly limited, and the composition for forming a thermosetting resin layer, when containing a solvent described below, is preferably dried by heating. For example, it is preferable to dry at 70 to 130 ° C. for 10 seconds to 5 minutes.

<Composition for forming resin layer (III-1)>
Examples of the thermosetting resin layer-forming composition include, for example, a thermosetting resin layer-forming composition (III-1) containing a polymer component (A) and a thermosetting component (B) (in the present specification). May be simply abbreviated as “resin layer-forming composition (III-1)”).

[Polymer component (A)]
The polymer component (A) is a polymer compound for imparting a film forming property, flexibility, and the like to the thermosetting resin layer.
The polymer component (A) contained in the resin layer forming composition (III-1) and the thermosetting resin layer may be used alone or in combination of two or more. Combinations and ratios can be arbitrarily selected.

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

The acrylic resin in the polymer component (A) includes a known acrylic polymer.
The weight average molecular weight (Mw) of the acrylic resin is preferably from 10,000 to 2,000,000, and more preferably from 100,000 to 1500,000. When the weight average molecular weight of the acrylic resin is equal to or more than the lower limit, the shape stability of the thermosetting resin layer (stability during storage) is improved. In addition, since the weight average molecular weight of the acrylic resin is equal to or less than the upper limit, the thermosetting resin layer easily follows the uneven surface of the adherend, and between the adherend and the thermosetting resin layer. Generation of voids and the like is further suppressed.

  The glass transition temperature (Tg) of the acrylic resin is preferably −60 to 70 ° C., and more preferably −30 to 50 ° C. When the Tg of the acrylic resin is equal to or greater than the lower limit, the adhesive force between the first protective film and the first support sheet is suppressed, and the releasability of the first support sheet is improved. Further, when the Tg of the acrylic resin is equal to or less than the upper limit, the adhesive strength between the thermosetting resin layer and the first protective film with the adherend is improved.

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

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

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

  The monomer constituting the acrylic resin may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  The acrylic resin may have a functional group that can bind to other compounds such as a vinyl group, a (meth) acryloyl group, an amino group, a hydroxyl group, a carboxy group, and an isocyanate group. The functional group of the acrylic resin may be bonded to another compound via a cross-linking agent (F) described later, or may be directly bonded to another compound without using a cross-linking agent (F). . When the acrylic resin is bonded to another compound by the functional group, the reliability of the package obtained using the first protective film forming sheet tends to be improved.

  In the present invention, as the polymer component (A), a thermoplastic resin other than an acrylic resin (hereinafter, may be simply abbreviated as “thermoplastic resin”) is used alone without using an acrylic resin. And may be used in combination with an acrylic resin. By using the thermoplastic resin, the releasability of the first protective film from the first support sheet is improved, and the thermosetting resin layer easily follows the uneven surface of the adherend. Occurrence of voids and the like with the curable resin layer may be further suppressed.

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

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

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

  The thermoplastic resin contained in the resin layer forming composition (III-1) and the thermosetting resin layer may be used alone or in combination of two or more. The ratio can be arbitrarily selected.

  In the resin layer forming composition (III-1), the ratio of the content of the polymer component (A) to the total content of all components other than the solvent (that is, the polymer component (A) of the thermosetting resin layer) Is preferably 5 to 85% by mass, more preferably 5 to 80% by mass, irrespective of the type of the polymer component (A).

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

[Thermosetting component (B)]
The thermosetting component (B) is a component for curing the thermosetting resin layer to form a hard first protective film.
The composition (III-1) for forming a resin layer and the thermosetting component (B) contained in the thermosetting resin layer may be used alone or in combination of two or more. And the ratio can be arbitrarily selected.

  Examples of the thermosetting component (B) include an epoxy thermosetting resin, thermosetting polyimide, polyurethane, unsaturated polyester, and silicone resin, and an epoxy thermosetting resin is preferable.

(Epoxy thermosetting resin)
The epoxy-based thermosetting resin comprises an epoxy resin (B1) and a thermosetting agent (B2).
The epoxy-based thermosetting resin contained in the resin layer-forming composition (III-1) and the thermosetting resin layer may be used alone or in combination of two or more. Combinations and ratios can be arbitrarily selected.

・ Epoxy resin (B1)
Examples of the epoxy resin (B1) include known ones, for example, a polyfunctional epoxy resin, a biphenyl compound, bisphenol A diglycidyl ether and its hydrogenated product, orthocresol novolak epoxy resin, dicyclopentadiene type epoxy resin, Biphenyl or higher functional epoxy compounds such as biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin and the like.

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

Examples of the epoxy resin having an unsaturated hydrocarbon group include compounds in which a part of the epoxy group of a polyfunctional epoxy resin is converted into a group having an unsaturated hydrocarbon group. Such a compound can be obtained, for example, by adding (meth) acrylic acid or a derivative thereof to an epoxy group.
Examples of the epoxy resin having an unsaturated hydrocarbon group include compounds in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring or the like constituting the epoxy resin.
The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include an ethenyl group (vinyl group), a 2-propenyl group (allyl group), a (meth) acryloyl group, and a (meth) group. An acrylamide group is exemplified, and an acryloyl group is preferable.

The number average molecular weight of the epoxy resin (B1) is not particularly limited, but is preferably from 300 to 30,000 from the viewpoint of the curability of the thermosetting resin layer, and the strength and heat resistance of the first protective film after curing. , More preferably from 400 to 10,000, and particularly preferably from 500 to 3,000.
The epoxy equivalent of the epoxy resin (B1) is preferably from 100 to 1000 g / eq, and more preferably from 300 to 800 g / eq.

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

・ Thermosetting agent (B2)
The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1).
Examples of the thermosetting agent (B2) include compounds having two or more functional groups capable of reacting with an epoxy group in one molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxy group, a group in which an acid group has been converted to an anhydride, and a phenolic hydroxyl group, an amino group, or an acid group in which an acid group has been converted to an anhydride. It is preferably a phenolic hydroxyl group or an amino group.

Among the thermal curing agents (B2), examples of the phenolic curing agent having a phenolic hydroxyl group include a polyfunctional phenol resin, biphenol, a novolak phenol resin, a dicyclopentadiene phenol resin, and an aralkyl phenol resin.
Among the thermosetting agents (B2), examples of the amine-based curing agent having an amino group include dicyandiamide (hereinafter sometimes abbreviated as “DICY”).

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

  When a phenolic curing agent is used as the thermal curing agent (B2), the thermal curing agent (B2) has a softening point or a glass transition temperature because the releasability of the first protective film from the first support sheet is improved. Tall ones are preferred.

Among the thermosetting agents (B2), for example, the number average molecular weight of the resin component such as a polyfunctional phenol resin, a novolak phenol resin, a dicyclopentadiene phenol resin, and an aralkyl phenol resin is preferably 300 to 30,000, It is more preferably from 400 to 10,000, and particularly preferably from 500 to 3,000.
Among the thermosetting agents (B2), for example, the molecular weight of non-resin components such as biphenol and dicyandiamide is not particularly limited, but is preferably, for example, 60 to 500.

  As the thermosetting agent (B2), one type may be used alone, or two or more types may be used in combination. When two or more types are used in combination, their combination and ratio can be arbitrarily selected.

  In the resin layer forming composition (III-1) and the thermosetting resin layer, the content of the thermosetting agent (B2) is 0.1 to 500 parts by mass based on 100 parts by mass of the epoxy resin (B1). The amount is preferably part by mass, more preferably from 1 to 200 parts by mass. When the content of the thermosetting agent (B2) is equal to or more than the lower limit, the thermosetting resin layer is more easily cured. In addition, when the content of the thermosetting agent (B2) is equal to or less than the upper limit, the moisture absorption of the thermosetting resin layer is reduced, and the content of the package obtained using the first protective film forming sheet is reduced. Reliability is further improved.

  In the resin layer forming composition (III-1) and the thermosetting resin layer, the content of the thermosetting component (B) (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is The amount is preferably 50 to 1000 parts by mass, more preferably 100 to 950 parts by mass, and particularly preferably 150 to 900 parts by mass, based on 100 parts by mass of the polymer component (A). preferable. When the content of the thermosetting component (B) is in such a range, the adhesion between the first protective film and the first support sheet is suppressed, and the releasability of the first support sheet is improved.

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

  The curing accelerator (C) contained in the composition (III-1) for forming a resin layer and the thermosetting resin layer may be used alone or in combination of two or more. Combinations and ratios can be arbitrarily selected.

  When the curing accelerator (C) is used, the content of the curing accelerator (C) in the composition (III-1) for forming a resin layer and the thermosetting resin layer is determined by the content of the thermosetting component (B). The amount is preferably from 0.01 to 10 parts by mass, more preferably from 0.1 to 5 parts by mass, per 100 parts by mass. When the content of the curing accelerator (C) is equal to or more than the lower limit, the effect of using the curing accelerator (C) is more remarkably obtained. When the content of the curing accelerator (C) is equal to or less than the upper limit, for example, a highly polar curing accelerator (C) adheres to the thermosetting resin layer in a high-temperature and high-humidity condition. The effect of suppressing segregation by moving to the bonding interface side with the body is increased, and the reliability of the package obtained using the first protective film forming sheet is further improved.

[Filler (D)]
The resin layer forming composition (III-1) and the thermosetting resin layer may contain a filler (D). When the thermosetting resin layer contains the filler (D), the first protective film obtained by curing the thermosetting resin layer can easily adjust the coefficient of thermal expansion. By optimizing the object for forming the first protective film, the reliability of the package obtained using the first protective film forming sheet is further improved. In addition, when the thermosetting resin layer contains the filler (D), the moisture absorption of the first protective film can be reduced and the heat dissipation can be improved.

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

  The filler (D) contained in the resin layer forming composition (III-1) and the thermosetting resin layer may be used alone or in combination of two or more. And the ratio can be arbitrarily selected.

  When the filler (D) is used, in the resin layer forming composition (III-1), the ratio of the content of the filler (D) to the total content of all components other than the solvent (that is, the thermosetting resin The content of the filler (D) in the layer) is preferably from 5 to 80% by mass, and more preferably from 7 to 60% by mass. When the content of the filler (D) is in such a range, the adjustment of the above-described coefficient of thermal expansion becomes easier.

[Coupling agent (E)]
The resin layer forming composition (III-1) and the thermosetting resin layer may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesiveness and the adhesiveness of the thermosetting resin layer to an adherend can be improved. Further, by using the coupling agent (E), the first protective film obtained by curing the thermosetting resin layer has improved water resistance without impairing heat resistance.

The coupling agent (E) is preferably a compound having a functional group capable of reacting with a functional group of the polymer component (A), the thermosetting component (B0), or the like, and is preferably a silane coupling agent. More preferred.
Preferred silane coupling agents include, for example, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-amino Ethylamino) propylmethyldiethoxysilane, 3- (phenylamino) propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyl Trimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolesilane and the like. Can be

  The coupling agent (E) contained in the resin layer forming composition (III-1) and the thermosetting resin layer may be used alone or in combination of two or more. Combinations and ratios can be arbitrarily selected.

  When the coupling agent (E) is used, the content of the coupling agent (E) in the resin layer forming composition (III-1) and the thermosetting resin layer is determined by adjusting the content of the polymer component (A) and the thermosetting resin. It is preferably from 0.03 to 20 parts by mass, more preferably from 0.05 to 10 parts by mass, and preferably from 0.1 to 5 parts by mass, based on 100 parts by mass of the total content of the component (B). It is particularly preferred that there is. When the content of the coupling agent (E) is equal to or more than the lower limit, the dispersibility of the filler (D) in the resin and the adhesion of the thermosetting resin layer to the adherend are improved. For example, the effect of using the coupling agent (E) is more remarkably obtained. Further, when the content of the coupling agent (E) is equal to or less than the upper limit, generation of outgas is further suppressed.

[Crosslinking agent (F)]
As the polymer component (A), one having a functional group such as a vinyl group, a (meth) acryloyl group, an amino group, a hydroxyl group, a carboxy group, or an isocyanate group, which can be bonded to another compound, such as the above-mentioned acrylic resin. When used, the resin layer forming composition (III-1) and the thermosetting resin layer may contain a crosslinking agent (F) for bonding the functional group to another compound to crosslink. By performing crosslinking using the crosslinking agent (F), the initial adhesive strength and cohesive strength of the thermosetting resin layer can be adjusted.

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

  Examples of the organic polyvalent isocyanate compound include an aromatic polyvalent isocyanate compound, an aliphatic polyvalent isocyanate compound, and an alicyclic polyvalent isocyanate compound (hereinafter, these compounds are collectively referred to as an “aromatic polyvalent isocyanate compound or the like”). May be abbreviated); trimers, isocyanurates, and adducts of the aromatic polyvalent isocyanate compound and the like; terminal isocyanate urethane prepolymer obtained by reacting the aromatic polyvalent isocyanate compound and the like with a polyol compound And the like. The "adduct body" is a mixture of the aromatic polyvalent isocyanate compound, the aliphatic polyvalent isocyanate compound or the alicyclic polyvalent isocyanate compound, and ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil. It means a reaction product with a compound having a molecular active hydrogen, and examples thereof include an adduct of xylylene diisocyanate of trimethylolpropane as described later. The term "terminal isocyanurethane prepolymer" is as described above.

  More specifically, as the organic polyvalent isocyanate compound, for example, 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylene diisocyanate; diphenylmethane-4 Diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; trimethylol To all or some of the hydroxyl groups of a polyol such as propane, any one of tolylene diisocyanate, hexamethylene diisocyanate and xylylene diisocyanate Like lysine diisocyanate and the like; the compound or two or more are added.

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

  When an organic polyvalent isocyanate compound is used as the crosslinking agent (F), it is preferable to use a hydroxyl group-containing polymer as the polymer component (A). When the crosslinking agent (F) has an isocyanate group and the polymer component (A) has a hydroxyl group, a reaction between the crosslinking agent (F) and the polymer component (A) causes a crosslinked structure to be formed in the thermosetting resin layer. It can be easily introduced.

  The crosslinking agent (F) contained in the resin layer forming composition (III-1) and the thermosetting resin layer may be used alone or in combination of two or more. And the ratio can be arbitrarily selected.

  When the cross-linking agent (F) is used, the content of the cross-linking agent (F) in the resin layer forming composition (III-1) is 0.1 to 100 parts by mass of the polymer component (A). It is preferably from 01 to 20 parts by mass, more preferably from 0.1 to 10 parts by mass, and particularly preferably from 0.5 to 5 parts by mass. When the content of the crosslinking agent (F) is equal to or more than the lower limit, the effect of using the crosslinking agent (F) is more remarkably obtained. When the content of the crosslinking agent (F) is equal to or less than the upper limit, the excessive use of the crosslinking agent (F) is suppressed.

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

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

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

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

  The energy ray-curable compound used in the polymerization may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  The energy ray-curable resin (G) contained in the resin layer forming composition (III-1) may be only one type, or two or more types, and when two or more types are used, their combination and ratio are You can choose any.

  In the composition (III-1) for forming a resin layer, the content of the energy ray-curable resin (G) is preferably from 1 to 95% by mass, more preferably from 2 to 90% by mass, and 3 It is particularly preferred that the content be 85% by mass.

[Photopolymerization initiator (H)]
When the composition (III-1) for forming a resin layer contains the energy ray-curable resin (G), in order to efficiently promote the polymerization reaction of the energy ray-curable resin (G), the photopolymerization initiator (H ) May be contained.

  As the photopolymerization initiator (H) in the composition (III-1) for forming a resin layer, the same photopolymerization initiator as in the first pressure-sensitive adhesive composition (I-1) can be used.

  The photopolymerization initiator (H) contained in the composition (III-1) for forming a resin layer may be only one type, or two or more types, and when two or more types are used, their combination and ratio are arbitrary. Can be selected.

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

[General purpose additive (I)]
The resin layer forming composition (III-1) and the thermosetting resin layer may contain the general-purpose additive (I) as long as the effects of the present invention are not impaired.
The general-purpose additive (I) may be a known one and can be arbitrarily selected according to the purpose, and is not particularly limited. Preferred examples include a plasticizer, an antistatic agent, an antioxidant, and a coloring agent (dye). , Pigments) and gettering agents.

The composition (III-1) for forming a resin layer and the general-purpose additive (I) contained in the thermosetting resin layer may be used alone or in combination of two or more. Combinations and ratios can be arbitrarily selected.
The contents of the resin layer forming composition (III-1) and the general-purpose additive (I) in the thermosetting resin layer are not particularly limited, and may be appropriately selected according to the purpose.

[solvent]
The composition (III-1) for forming a resin layer preferably further contains a solvent. The resin layer-forming composition (III-1) containing a solvent has good handleability.
The solvent is not particularly limited, but preferred are, for example, hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol) and 1-butanol. Esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone.
The solvent contained in the resin layer forming composition (III-1) may be only one kind, two or more kinds, and when two or more kinds, the combination and the ratio thereof can be arbitrarily selected.

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

<< Production method of composition for forming thermosetting resin layer >>
The composition for forming a thermosetting resin layer such as the composition for forming a resin layer (III-1) is obtained by blending each component for constituting the composition.
The order of addition of each component 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 of the components other than the solvent, and may be used by previously diluting the components, or may be used by diluting any of the components other than the solvent in advance. Alternatively, a solvent may be used by mixing with these components.
The method of mixing each component at the time of blending is not particularly limited, and a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by adding ultrasonic waves, and the like. What is necessary is just to select suitably.
The temperature and time during addition and mixing of each component are not particularly limited as long as each component is not deteriorated, and may be appropriately adjusted, but the temperature is preferably 15 to 30 ° C.

○ Energy ray-curable resin layer The energy ray-curable resin layer contains an energy ray-curable component (a).
The energy ray-curable component (a) is preferably uncured, and preferably has tackiness, and more preferably is uncured and has tackiness. Here, “energy ray” and “energy ray curability” are as described above.

  The energy ray-curable resin layer may be only one layer (single layer), or two or more layers, and in the case of a plurality of layers, these layers may be the same or different from each other. The combination of layers is not particularly limited.

The thickness of the energy ray-curable resin layer is preferably from 1 to 100 μm, more preferably from 5 to 75 μm, and particularly preferably from 5 to 50 μm. When the thickness of the energy ray-curable resin layer is equal to or more than the lower limit, the first protective film having higher protection ability can be formed. When the thickness of the energy ray-curable resin layer is equal to or less than the upper limit, an excessive thickness is suppressed.
Here, “the thickness of the energy ray-curable resin layer” means the thickness of the entire energy ray-curable resin layer. For example, the thickness of the energy ray-curable resin layer composed of a plurality of layers is It means the total thickness of all the layers constituting the curable resin layer.

The energy ray-curable resin layer is adhered to the bump forming surface of the semiconductor wafer and cured to form a first protective film under such curing conditions that the first protective film sufficiently exhibits its function. The temperature is not particularly limited as long as the temperature is high, and may be appropriately selected according to the type of the thermosetting resin layer.
For example, the illuminance of the energy beam during curing of the energy beam-curable resin layer is preferably from 180 to 280 mW / cm ² . It is preferable that the amount of energy rays during the curing is 450 to 1000 mJ / cm ² .

<< energy ray-curable resin layer forming composition >>
The energy ray-curable resin layer can be formed using an energy ray-curable resin layer-forming composition containing the constituent material. For example, an energy ray-curable resin layer composition is applied to the surface on which the energy ray-curable resin layer is to be formed, and dried as necessary to form an energy ray-curable resin layer at a target portion. it can. In the composition for forming an energy beam-curable resin layer, the content ratio of components that do not vaporize at room temperature is usually the same as the content ratio of the components of the energy beam-curable resin layer. Here, “normal temperature” is as described above.

  The application of the composition for forming an energy ray-curable resin layer may be performed by a known method, for example, an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, and a die coater. , A knife coater, a screen coater, a Meyer bar coater, a kiss coater and the like.

  The drying conditions of the energy ray-curable resin layer forming composition are not particularly limited, but when the energy ray-curable resin layer forming composition contains a solvent described below, it is preferable to heat and dry the composition. In this case, for example, drying at 70 to 130 ° C. for 10 seconds to 5 minutes is preferable.

<Composition for forming resin layer (IV-1)>
Examples of the composition for forming an energy-ray-curable resin layer include, for example, a composition for forming an energy-ray-curable resin layer (IV-1) containing the energy-ray-curable component (a) (in this specification, simply "The composition for forming a resin layer (IV-1)" is sometimes abbreviated).

[Energy ray-curable component (a)]
The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and is also a component for imparting film forming properties, flexibility, and the like to the energy ray-curable resin layer.
Examples of the energy ray-curable component (a) include a polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000, and a polymer having an energy ray-curable group and a molecular weight of 100 to 80,000. Compound (a2) is mentioned. The polymer (a1) may be at least partially cross-linked by a cross-linking agent, or may be non-cross-linked.

(Polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000)
Examples of the polymer (a1) having an energy ray-curable group and having a weight average molecular weight of 80,000 to 2,000,000 include, for example, an acrylic polymer (a11) having a functional group capable of reacting with a group of another compound; An acrylic resin (a1-1) obtained by performing an addition reaction with a group that reacts with a functional group and an energy ray-curable compound (a12) having an energy ray-curable group such as an energy ray-curable double bond. Can be

Examples of the functional group capable of reacting with a group possessed by another compound include a hydroxyl group, a carboxy group, an amino group, and a substituted amino group (in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom. And an epoxy group. However, from the viewpoint of preventing corrosion of circuits such as semiconductor wafers and semiconductor chips, the functional groups are preferably groups other than carboxy groups.
Among them, the functional group is preferably a hydroxyl group.

Acrylic polymer having functional group (a11)
Examples of the acrylic polymer having a functional group (a11) include those obtained by copolymerizing an acrylic monomer having the functional group and an acrylic monomer having no functional group. In addition to the monomer, a monomer (non-acrylic monomer) other than the acrylic monomer may be copolymerized.
Further, the acrylic polymer (a11) may be a random copolymer or a block copolymer.

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

  Examples of the hydroxyl group-containing monomer include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) Hydroxyalkyl (meth) acrylates such as 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; non- (meth) acrylic resins such as vinyl alcohol and allyl alcohol; And saturated alcohols (unsaturated alcohols having no (meth) acryloyl skeleton).

  Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth) acrylic acid and crotonic acid; fumaric acid, itaconic acid, maleic acid, citracone Ethylenically unsaturated dicarboxylic acids such as acids (dicarboxylic acids having an ethylenically unsaturated bond); anhydrides of the above-mentioned ethylenically unsaturated dicarboxylic acids; and carboxyalkyl (meth) acrylates such as 2-carboxyethyl methacrylate. Can be

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

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

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

  Examples of the acrylic monomer having no functional group include methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, and ethoxyethyl (meth) acrylate. (Meth) acrylic esters having an aromatic group, including (meth) acrylic esters containing alkyl groups; aryl (meth) acrylates such as phenyl (meth) acrylate; non-crosslinkable (meth) acrylamide; Derivatives thereof; (meth) acrylates having a non-crosslinkable tertiary amino group such as N, N-dimethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate; .

  The acrylic monomer having no functional group that constitutes the acrylic polymer (a11) may be only one kind, or two or more kinds, and when two or more kinds, the combination and ratio thereof are arbitrary. Can be selected.

Examples of the non-acrylic monomer include olefins such as ethylene and norbornene; vinyl acetate; and styrene.
The non-acrylic monomer constituting the acrylic polymer (a11) may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

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

  The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be one type alone, or two or more types in combination, and when two or more types are used, the combination and ratio thereof are arbitrary. You can choose.

  In the composition (IV-1) for forming a resin layer, the content of the acrylic resin (a1-1) is preferably 1 to 40% by mass, more preferably 2 to 30% by mass, and 3% by mass. It is particularly preferable that the content is from 20 to 20% by mass.

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

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

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

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

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

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

  When at least a part of the polymer (a1) is cross-linked by a cross-linking agent, the polymer (a1) is described above as constituting the acrylic polymer (a11). A monomer that does not correspond to any of the monomers and has a group that reacts with the cross-linking agent may be polymerized and cross-linked at the group that reacts with the cross-linking agent, or the energy ray-curable compound ( A group derived from a12) that reacts with the functional group may be crosslinked.

  The polymer (a1) contained in the resin layer forming composition (IV-1) and the energy ray-curable resin layer may be used alone or in combination of two or more. And the ratio can be arbitrarily selected.

(Compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80000)
As the energy ray-curable group of the compound (a2) having an energy ray-curable group and having a molecular weight of 100 to 80,000, a group containing an energy ray-curable double bond is mentioned, and (meth) is preferred. Examples include an acryloyl group and a vinyl group.

  The compound (a2) is not particularly limited as long as it satisfies the above conditions, and includes a low molecular weight compound having an energy ray-curable group, an epoxy resin having an energy ray-curable group, and an energy ray-curable group. Phenol resins and the like can be mentioned.

Among the compounds (a2), examples of the low molecular weight compound having an energy ray-curable group include polyfunctional monomers or oligomers, and an acrylate compound having a (meth) acryloyl group is preferable.
Examples of the acrylate compound include 2-hydroxy-3- (meth) acryloyloxypropyl methacrylate, polyethylene glycol di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, and 2,2-bis [4 -((Meth) acryloxypolyethoxy) phenyl] propane, ethoxylated bisphenol A di (meth) acrylate, 2,2-bis [4-((meth) acryloxydiethoxy) phenyl] propane, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene, 2,2-bis [4-((meth) acryloxypolypropoxy) phenyl] propane, tricyclodecanedimethanol di (meth) acrylate, 1 , 10-Decandiol di (meth) acryle 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) ) Acrylate, polytetramethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 2,2-bis [4-((meth) acrylic) Roxyethoxy) phenyl] propane, neopentyl glycol di (meth) acrylate, ethoxylated polypropylene glycol di (meth) acrylate, 2-hydroxy-1,3-di (meth) acryloxypropane, etc. Data) acrylate;
Tris (2- (meth) acryloxyethyl) isocyanurate, ε-caprolactone-modified tris- (2- (meth) acryloxyethyl) isocyanurate, ethoxylated glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, Trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol poly (meth) acrylate, dipentaerythritol hexa ( Polyfunctional (meth) acrylates such as (meth) acrylate;
Examples include polyfunctional (meth) acrylate oligomers such as urethane (meth) acrylate oligomers.

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

  The compound (a2) preferably has a weight average molecular weight of 100 to 30,000, more preferably 300 to 10,000.

  The compound (a2) contained in the resin layer forming composition (IV-1) and the energy ray-curable resin layer may be used alone or in combination of two or more. Combinations and ratios can be arbitrarily selected.

[Polymer (b) having no energy beam-curable group]
When the composition (IV-1) for forming a resin layer and the energy-ray-curable resin layer contain the compound (a2) as the energy-ray-curable component (a), the resin having no energy-ray-curable group. It is also preferable to contain the coalescence (b).
The polymer (b) may be at least partially cross-linked by a cross-linking agent, or may be non-cross-linked.

Examples of the polymer (b) having no energy ray-curable group include an acrylic polymer, a phenoxy resin, a urethane resin, a polyester, a rubber resin, and an acrylic urethane resin.
Among these, the polymer (b) is preferably an acrylic polymer (hereinafter may be abbreviated as “acrylic polymer (b-1)”).

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

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

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

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

Examples of the glycidyl group-containing (meth) acrylate include glycidyl (meth) acrylate.
Examples of the hydroxyl group-containing (meth) acrylate include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 3-hydroxy (meth) acrylate. Propyl, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like.
Examples of the substituted amino group-containing (meth) acrylate include N-methylaminoethyl (meth) acrylate.

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

Examples of the polymer (b) having at least a part thereof crosslinked by a crosslinking agent and having no energy ray-curable group include those in which a reactive functional group in the polymer (b) has reacted with a crosslinking agent. No.
The reactive functional group may be appropriately selected according to the type of the crosslinking agent and the like, and is not particularly limited. For example, when the cross-linking agent is a polyisocyanate compound, examples of the reactive functional group include a hydroxyl group, a carboxy group, and an amino group. Among these, a hydroxyl group having high reactivity with the isocyanate group is preferable. When the crosslinking agent is an epoxy-based compound, examples of the reactive functional group include a carboxy group, an amino group, and an amide group. Among these, a carboxy group having high reactivity with an epoxy group is preferable. . However, it is preferable that the reactive functional group is a group other than a carboxy group from the viewpoint of preventing corrosion of a circuit of a semiconductor wafer or a semiconductor chip.

  As the polymer (b) having the reactive functional group and not having the energy ray-curable group, for example, a polymer obtained by polymerizing at least the monomer having the reactive functional group may be mentioned. In the case of the acrylic polymer (b-1), those having the reactive functional group as one or both of the acrylic monomer and the non-acrylic monomer, which are listed as the monomer constituting the acrylic polymer (b-1), It may be used. For example, as the polymer (b) having a hydroxyl group as a reactive functional group, for example, a polymer obtained by polymerizing a hydroxyl group-containing (meth) acrylic acid ester may be mentioned. Examples of the acrylic monomer or non-acrylic monomer include those obtained by polymerizing a monomer in which one or more hydrogen atoms are substituted with the reactive functional group.

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

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

  The polymer (b) having no energy ray-curable group contained in the resin layer-forming composition (IV-1) and the energy ray-curable resin layer may be used alone or in combination of two or more kinds. When two or more kinds are used, their combination and ratio can be arbitrarily selected.

  Examples of the resin layer-forming composition (IV-1) include those containing one or both of the polymer (a1) and the compound (a2). When the composition (IV-1) for forming a resin layer contains the compound (a2), the composition (IV-1) preferably further contains a polymer (b) having no energy ray-curable group. It is also preferable to contain the above (a1). The resin layer forming composition (IV-1) does not contain the compound (a2), and contains both the polymer (a1) and the polymer (b) having no energy ray-curable group. May be.

  When the composition (IV-1) for forming a resin layer contains the polymer (a1), the compound (a2), and the polymer (b) having no energy ray-curable group, the composition for forming a resin layer In (IV-1), the content of the compound (a2) is 10 to 10 parts by mass based on 100 parts by mass of the total content of the polymer (a1) and the polymer (b) having no energy ray-curable group. The amount is preferably 400 parts by mass, more preferably 30 to 350 parts by mass.

  In the resin layer forming composition (IV-1), the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group with respect to the total content of components other than the solvent. (That is, the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group in the energy ray-curable resin layer) is 5 to 90% by mass. Is preferably 10 to 80% by mass, more preferably 20 to 70% by mass. When the content of the energy ray-curable component is in such a range, the energy ray curability of the energy ray-curable resin layer is further improved.

  The resin layer-forming composition (IV-1) may contain, in addition to the energy ray-curable component, a thermosetting component, a photopolymerization initiator, a filler, a coupling agent, a crosslinking agent, and a general-purpose additive, depending on the purpose. Or one or more selected from the group consisting of: For example, by using the resin layer forming composition (IV-1) containing the energy ray-curable component and the thermosetting component, the formed energy ray-curable resin layer is bonded to the adherend by heating. The force is improved, and the strength of the first protective film formed from the energy ray-curable resin layer is also improved.

  The thermosetting component, the photopolymerization initiator, the filler, the coupling agent, the crosslinking agent, and the general-purpose additive in the resin layer forming composition (IV-1) are respectively the resin layer forming composition (III- The same as the thermosetting component (B), the photopolymerization initiator (H), the filler (D), the coupling agent (E), the cross-linking agent (F) and the general-purpose additive (I) in 1) can be mentioned. .

In the resin layer-forming composition (IV-1), the thermosetting component, the photopolymerization initiator, the filler, the coupling agent, the crosslinking agent, and the general-purpose additive may each be used alone. However, two or more kinds may be used in combination, and when two or more kinds are used in combination, their combination and ratio can be arbitrarily selected.
The content of the thermosetting component, the photopolymerization initiator, the filler, the coupling agent, the crosslinking agent, and the general-purpose additive in the resin layer forming composition (IV-1) may be appropriately adjusted depending on the purpose. Is not particularly limited.

The composition (IV-1) for forming a resin layer preferably further contains a solvent since the handleability is improved by dilution.
Examples of the solvent contained in the resin layer forming composition (IV-1) include the same solvents as those in the resin layer forming composition (III-1).
The solvent contained in the resin layer forming composition (IV-1) may be only one kind or two or more kinds.

<<< Method for producing composition for forming energy ray-curable resin layer >>>
The composition for forming an energy ray-curable resin layer such as the composition for forming a resin layer (IV-1) is obtained by blending each component for constituting the composition.
The order of addition of each component 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 of the components other than the solvent, and may be used by previously diluting the components, or may be used by diluting any of the components other than the solvent in advance. Alternatively, a solvent may be used by mixing with these components.
The method of mixing each component at the time of blending is not particularly limited, and a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by adding ultrasonic waves, and the like. What is necessary is just to select suitably.
The temperature and time during addition and mixing of each component are not particularly limited as long as each component is not deteriorated, and may be appropriately adjusted, but the temperature is preferably 15 to 30 ° C.

製造 Method of Manufacturing First Protective Film Forming Sheet The first protective film forming sheet can be manufactured by sequentially laminating the above-described respective layers in a corresponding positional relationship. The method for forming each layer is as described above.
For example, when manufacturing the first support sheet, when laminating the first pressure-sensitive adhesive layer or the first intermediate layer on the first base material, the first pressure-sensitive adhesive composition or the above-described first pressure-sensitive adhesive composition on the first base material The first pressure-sensitive adhesive layer or the first intermediate layer can be laminated by applying the composition for forming the first intermediate layer and drying it as necessary, or by irradiating it with energy rays.

  On the other hand, for example, when a curable resin layer is further laminated on the first pressure-sensitive adhesive layer already laminated on the first base material, the composition for forming a thermosetting resin layer is formed on the first pressure-sensitive adhesive layer. The composition or the composition for forming an energy-ray-curable resin layer can be applied to directly form the curable resin layer. Similarly, when further laminating the first pressure-sensitive adhesive layer on the first intermediate layer already laminated on the first base material, the first pressure-sensitive adhesive composition is applied on the first intermediate layer. It is possible to directly form the first pressure-sensitive adhesive layer. As described above, when a continuous two-layer structure is formed using any one of the compositions, the composition is further applied on the layer formed from the composition to form a new layer. Can be formed. However, a layer to be laminated later of these two layers is formed in advance on another release film using the composition, and the layer that has been formed is in contact with the release film in contact with the release film. It is preferable to form a continuous two-layer laminated structure by bonding the exposed surface on the opposite side to the exposed surface of the remaining layer already formed. At this time, the composition is preferably applied to a release-treated surface of a release film. The release film may be removed as necessary after the formation of the laminated structure.

For example, a first protective film forming sheet in which a first pressure-sensitive adhesive layer is laminated on a first base material and a curable resin layer is laminated on the first pressure-sensitive adhesive layer (the first support sheet is a first base material). In the case of producing a first protective film forming sheet which is a laminate of the material and the first pressure-sensitive adhesive layer), the first pressure-sensitive adhesive composition is applied on the first base material, and dried if necessary. By laminating the first pressure-sensitive adhesive layer on the first base material, a composition for forming a thermosetting resin layer or a composition for forming an energy ray-curable resin layer is separately coated on a release film. By drying as necessary, a curable resin layer is formed on the release film, and the exposed surface of the curable resin layer is exposed to the first adhesive layer already laminated on the first base material. The first protective film forming sheet is obtained by laminating the curable resin layer on the first pressure-sensitive adhesive layer by bonding to the surface.
Further, for example, when manufacturing a first support sheet in which a first intermediate layer is laminated on a first base material and a first pressure-sensitive adhesive layer is laminated on the first intermediate layer, the first base material is used. The first intermediate layer forming composition is applied thereon, and is dried or irradiated with energy rays as necessary, thereby laminating the first intermediate layer on the first base material. The first pressure-sensitive adhesive composition is applied on the release film, and dried as necessary to form a first pressure-sensitive adhesive layer on the release film, and the exposed surface of the first pressure-sensitive adhesive layer is The first support sheet is obtained by laminating the first pressure-sensitive adhesive layer on the first intermediate layer by bonding the first pressure-sensitive adhesive layer to the exposed surface of the first intermediate layer already laminated on the first base material. In this case, for example, further separately, by coating the composition for forming a thermosetting resin layer or the composition for forming an energy-ray-curable resin layer on a release film, and drying the composition as necessary, on the release film. A curable resin layer is formed, and the exposed surface of the curable resin layer is bonded to the exposed surface of the first pressure-sensitive adhesive layer already laminated on the first intermediate layer. By laminating on the agent layer, a first protective film forming sheet is obtained.

When the first pressure-sensitive adhesive layer or the first intermediate layer is laminated on the first substrate, as described above, the first pressure-sensitive adhesive composition or the first intermediate layer-forming composition is formed on the first substrate. Instead of the method of coating the object, the first pressure-sensitive adhesive composition or the first intermediate layer forming composition is coated on a release film, and dried or irradiated with energy rays as necessary. First, the first pressure-sensitive adhesive layer or the first intermediate layer is formed on the release film, and the exposed surface of these layers is bonded to one surface of the first base material to form the first pressure-sensitive adhesive layer or the first pressure-sensitive adhesive layer. An intermediate layer may be laminated on the first substrate.
In any method, the release film may be removed at an arbitrary timing after the formation of the desired laminated structure.

  As described above, any layer other than the first base material constituting the first protective film forming sheet can be formed in advance on a release film and laminated by a method of bonding to a surface of a target layer. The first protective film forming sheet may be manufactured by appropriately selecting a layer adopting such a process as needed.

  Note that the first protective film forming sheet is usually stored in a state where a release film is bonded to the surface of the outermost layer (for example, a curable resin layer) on the side opposite to the first support sheet. Therefore, on this release film (preferably, the release-treated surface), a layer for forming the outermost layer, such as a composition for forming a thermosetting resin layer or a composition for forming an energy ray-curable resin layer, is formed. By coating the composition and drying if necessary, a layer constituting the outermost layer is formed on the release film, and the exposed surface on the side opposite to the side in contact with the release film of this layer The first protective film forming sheet can also be obtained by laminating the remaining layers on any one of the above-mentioned methods and keeping the laminated state without removing the release film.

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

The components used in the production of the composition for forming a thermosetting resin layer are shown below.
Polymer component Polymer component (A) -1: butyl acrylate (hereinafter abbreviated as “BA”) (55 parts by mass), methyl acrylate (hereinafter abbreviated as “MA”) (10 parts by mass) Acrylic resin obtained by copolymerizing glycidyl methacrylate (hereinafter abbreviated as "GMA") (20 parts by mass) and 2-hydroxyethyl acrylate (hereinafter abbreviated as "HEA") (15 parts by mass) Resin (weight average molecular weight 800,000, glass transition temperature -28 ° C).
Polymer component (A) -2: an acrylic resin obtained by copolymerizing MA (85 parts by mass) and HEA (15 parts by mass) (weight average molecular weight 370000, glass transition temperature 4 ° C).
Epoxy resin Epoxy resin (B1) -1: mixture of liquid bisphenol A type epoxy resin and fine particles of acrylic rubber ("BPA328" manufactured by Nippon Kayaku Co., Ltd.)
Epoxy resin (B1) -2: o-cresol novolak type epoxy resin ("EOCN104S" manufactured by Nippon Kayaku Co., Ltd.)
Epoxy resin (B1) -3: dicyclopentadiene type epoxy resin ("HP-7200HH" manufactured by Nippon Kayaku Co., Ltd.)
-Thermal curing agent Thermal curing agent (B2) -1: DICY ("EH-3636AS" manufactured by ADEKA, active hydrogen amount 21 g / eq)
・ Curing accelerator Curing accelerator (C) -1: 2-phenyl-4,5-dihydroxymethylimidazole (“Curesol 2PHZ-PW” manufactured by Shikoku Chemicals)
-Filler Filler (D) -1: spherical silica modified with an epoxy group ("SC2050-MA" manufactured by Admatechs)
Coupling agent Coupling agent (E) -1: a silicate compound to which γ-glycidoxypropyltrimethoxysilane is added (“MKC silicate MSEP2” manufactured by Mitsubishi Chemical Corporation)
-Energy ray-curable resin Energy ray-curable resin (G) -1: dicyclopentanyl acrylate ("KAYARAD R-684" manufactured by Nippon Kayaku Co., Ltd., ultraviolet curable resin)
-Photopolymerization initiator Photopolymerization initiator (H) -1: 1-hydroxycyclohexyl phenyl ketone ("IRGACURE 184" manufactured by BASF)

[Production Example 1]
(Production of adhesive resin (I-2a))
An acrylic polymer was obtained by performing a polymerization reaction using 2-ethylhexyl acrylate (hereinafter abbreviated as "2EHA") (80 parts by mass) and HEA (20 parts by mass) as a raw material of the copolymer. .
To this acrylic polymer, 2-methacryloyloxyethyl isocyanate (hereinafter abbreviated as “MOI”) (22 parts by mass, about 80 mol% based on HEA) is added, and added at 50 ° C. for 48 hours in an air stream. The target adhesive resin (I-2a) was obtained by carrying out the reaction.

[Example 1]
<Manufacture of sheet for forming first protective film>
(Production of a composition for forming a thermosetting resin layer)
Polymer component (A) -1, epoxy resin (B1) -1, epoxy resin (B1) -2, epoxy resin (B1) -3, thermosetting agent (B2) -1, curing accelerator (C) -1 , A filler (D) -1, a coupling agent (E) -1, an energy ray-curable resin (G) -1, and a photopolymerization initiator (H) -1. By dissolving or dispersing in methyl ethyl ketone so as to have the value shown in Table 1, and stirring the mixture at 23 ° C, the composition for forming a thermosetting resin layer has a resin layer composition having a solid content concentration of 50% by mass ( III-1) was obtained. In addition, the description of "-" in the column of the contained component in Table 1 means that the composition for forming a thermosetting resin layer does not contain the component.

(Production of First Adhesive Composition)
To the adhesive resin (I-2a) (100 parts by mass) obtained in Production Example 1, as a isocyanate-based cross-linking agent, a trimethylolpropane tolylene diisocyanate trimer adduct (“Coronate L” manufactured by Tosoh Corporation) ) (0.5 parts by mass) and stirred at 23 ° C. to obtain a first pressure-sensitive adhesive composition (I-2) having a solid concentration of 30% by mass as the first pressure-sensitive adhesive composition. . Note that all of the blending parts in “Production of the first pressure-sensitive adhesive composition” are values in terms of solid content.

(Production of sheet for forming first protective film)
The first pressure-sensitive adhesive composition obtained above was applied to the release-treated surface of a release film (“SP-PET381031” manufactured by Lintec Corporation, thickness 38 μm) in which one surface of a polyethylene terephthalate film was subjected to release treatment by silicone treatment. Then, by heating and drying at 120 ° C. for 2 minutes, a first pressure-sensitive adhesive layer having a thickness of 60 μm was formed.
Next, on the exposed surface of the first pressure-sensitive adhesive layer, as a first base material, a polyolefin film (thickness: 25 μm), an adhesive layer (thickness: 2.5 μm), a polyethylene terephthalate film (thickness: 50 μm), an adhesive layer (Thickness 2.5 μm) and a polyolefin film (thickness 25 μm) were laminated in this order, and a laminated film having a thickness of 105 μm was laminated to obtain a first support sheet.

  The composition for forming a thermosetting resin layer obtained above on the release-treated surface of a release film (“SP-PET381031” manufactured by Lintec Co., Ltd., thickness 38 μm) in which one surface of a polyethylene terephthalate film is release-treated by silicone treatment. The product was applied and dried at 100 ° C. for 2 minutes to prepare a thermosetting resin film (thermosetting resin layer) having a thickness of 40 μm.

  Next, the release film is removed from the first pressure-sensitive adhesive layer of the first support sheet obtained above, and the exposed surface of the thermosetting resin film obtained above is bonded to the exposed surface of the first pressure-sensitive adhesive layer. Thus, a first protective film forming sheet was obtained in which the first base material, the first pressure-sensitive adhesive layer, the thermosetting resin layer, and the release film were laminated in this thickness direction in this order.

<Evaluation of cured product of thermosetting resin film>
(Measurement of chloride ion content)
The composition for forming a thermosetting resin layer obtained above on the release-treated surface of a release film (“SP-PET381031” manufactured by Lintec Co., Ltd., thickness 38 μm) in which one surface of a polyethylene terephthalate film is release-treated by silicone treatment. The product was applied and dried at 100 ° C. for 2 minutes to prepare a thermosetting resin film (thermosetting resin layer) having a thickness of 50 μm. Four such thermosetting resin films are prepared by laminating a thermosetting resin film on a release film, and these thermosetting resin films are bonded to each other to form a 200-μm-thick thermosetting resin film having a four-layer structure. Produced.
Next, the thermosetting resin film having the four-layer structure was heated at 160 ° C. for 1 hour to perform thermosetting to obtain a cured product (that is, a first protective film).
Next, in a vessel made of polytetrafluoroethylene for measuring ion concentration, the obtained cured product is mixed with 20 mL of pure water per 1 g of the cured product, and the mixture is heated at 125 ° C. for 20 hours to obtain an extracted water. Was.
The chloride ion concentration of the obtained extraction water was measured by ion chromatography (measurement apparatus: “DX-320” manufactured by Nippon Dionex). Table 1 shows the results.

(Confirmation of insulation durability)
Two comb-shaped electrodes having a comb-like shape and having a two-layer structure in which a copper layer having a thickness of 100 μm and a titanium layer having a thickness of 30 μm were laminated were prepared. The width of many convex portions corresponding to the comb teeth of these comb electrodes was 80 μm. Then, with one comb-shaped electrode serving as a cathode and the other comb-shaped electrode serving as an anode, these terminal portions are directed in the same direction, and the convex portions corresponding to these comb teeth are such that the cathode and the anode are alternated. Then, a comb-shaped electrode was arranged on a glass plate so as to face each other with an interval of 20 μm. At this time, both of the comb electrodes were arranged with the titanium layer in contact with the glass plate.
Further, the thermosetting resin layer formed above was formed on the release-treated surface of a release film (“SP-PET381031” manufactured by Lintec Co., thickness 38 μm) in which one surface of a polyethylene terephthalate film was release-treated by silicone treatment. The composition for use was applied and dried at 100 ° C. for 2 minutes to prepare a thermosetting resin film (thermosetting resin layer) having a thickness of 60 μm.
Next, the thermosetting resin film obtained above was bonded on the comb-shaped electrodes arranged in combination on the glass plate (that is, on the copper layer of the comb-shaped electrodes). Thermal curing was performed by heating for a time to obtain a cured product (that is, a first protective film).
Next, the laminated structure of the comb-shaped electrode and the cured product is placed in an environment at a temperature of 130 ° C. and a relative humidity of 85%, and a DC voltage of 5 V is applied to the comb-shaped electrode to cause a short-circuit (short-circuit) in the cured product. The time until occurrence was measured to confirm the degree of insulation durability of the cured product. Table 1 shows the results.

<Production of first protective film forming sheet, evaluation of cured product of thermosetting resin film>
[Examples 2 and 3, Comparative Example 1]
A first protective film forming sheet was produced in the same manner as in Example 1 except that the components and contents of the composition for forming a thermosetting resin layer were as shown in Table 1, and a thermosetting resin film was formed. The cured product was evaluated. Table 1 shows the results.

As is clear from the above results, the cured products of Examples 1 to 3 in which the content of chloride ions is 5 ppm or less require a long time to cause short-circuit or do not cause short-circuit, and It was excellent.
On the other hand, in the cured product of Comparative Example 1 having a chloride ion content of more than 10 ppm, short-circuiting was observed in a short time, and insulation durability was poor.

  INDUSTRIAL APPLICATION This invention can be utilized for manufacture of the semiconductor chip etc. which have a bump in a connection pad part used by a flip-chip mounting method.

  1, 2, 3 ... first protective film forming sheet, 11 ... first substrate, 11a ... surface of first substrate, 12 ... curable resin layer (curable resin film) , 12 ': first protective film, 13: first adhesive layer, 13a: surface of first adhesive layer, 14: first intermediate layer, 101, 102, 103 ... First support sheet, 101a, 102a, 103a: Surface of first support sheet, 90: Semiconductor wafer, 90a: Circuit surface of semiconductor wafer, 91: Bump, 91a: Surface of bump

Claims (1)

A first protective sheet comprising, on one surface of a first support sheet, a curable resin film for forming a first protective film on the surface by attaching to a surface having bumps of a semiconductor wafer and curing the surface; A film forming sheet ,
The curable resin film includes an acrylic resin, an epoxy resin, and an amine curing agent,
For a content of 100 parts by mass of the acrylic resin, the total content of the epoxy resin and the amine-based curing agent is 150 to 900 parts by mass,
When the curable resin film is cured to form a cured product, and under conditions of 125 ° C. and 20 hours, chloride ions are extracted with hot water from the cured product, and the concentration of chloride ions in the obtained extracted water is measured. The first protective film forming sheet , wherein the content of chloride ions in the cured product is 6 ppm or less based on the mass of the cured product.

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