TWI885091B - Sheet for forming protective film, method for manufacturing semiconductor wafer with protective film, method for manufacturing semiconductor chip with protective film, and method for manufacturing semiconductor package - Google Patents

Abstract

The subject is to provide a protective film forming sheet that can suppress short circuits between bumps with narrow pitches. The subject is solved by making a protective film forming sheet having a laminated structure of a curable resin film (x) and a supporting sheet (Y), which is used to form a protective film (X) on the bump forming surface of a semiconductor wafer having a plurality of bumps and satisfying a specific requirement of showing bumps with narrow pitches, and satisfies a specific requirement specified by a tensile elastic modulus E'.

Description

Sheet for forming protective film, method for manufacturing semiconductor wafer with protective film, method for manufacturing semiconductor chip with protective film, and method for manufacturing semiconductor package

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

In the past, when a multi-pin LSI package used in an MPU or gate array is mounted on a printed wiring board, a semiconductor chip with a convex electrode (hereinafter also referred to as a "bump") formed on the connection pad has been used. In addition, a flip chip mounting method has been adopted, which is to make the bumps face the corresponding terminal part on the chip mounting substrate in a so-called face-down manner and make them contact, and perform fusion bonding or diffusion bonding.

In recent years, as electronic devices have become smaller, lighter, thinner, and more functional, high-density mounting is required even for built-in electronic components. Patent documents 1 to 3 propose solder materials with low α-radiation levels in order to avoid the problem associated with high-density mounting, namely, the problem of soft errors in which the memory content is overwritten due to the penetration of α-radiation into the memory cells of semiconductor integrated circuits. [Prior technical document] [Patent document]

[Patent Document 1] Japanese Patent Publication No. 4472752 [Patent Document 2] Japanese Patent Publication No. 2011-214040 [Patent Document 3] International Publication No. 2012/120982

[The problem that the invention wants to solve]

In addition, as the demand for high-density mounting of electronic components increases, the demand for narrower pitches of bumps on semiconductor chips is also gradually increasing. However, if the bumps on semiconductor chips are pitched narrower, new problems will arise. For example, in the step of electrically connecting the semiconductor chip to the wiring substrate via the spherical bumps, the spherical bumps may collapse and expand laterally, and the spherical bumps may contact each other and cause a short circuit. In addition, in order to meet the demand for higher-density mounting, there is also a review of three-dimensional high-density mounting that stacks semiconductor packages in the height direction, but in this case, the spherical bumps may gradually collapse due to the weight of the semiconductor package itself, resulting in a short circuit.

The inventors of the present invention have carefully examined the above problems and have achieved the goal of creating a thin sheet for forming a protective film that can suppress the lateral expansion of ball bumps due to collapse. In addition, it is believed that in semiconductor chips with columnar bumps, there may be a situation where the columnar bumps contact each other due to bending of the columnar bumps, etc., causing short circuits. It is known that the created thin sheet is also effective in solving this problem of columnar bumps.

Therefore, the subject of the present invention is to provide a thin sheet for forming a protective film, which can suppress short circuits between bumps with narrow pitches. [Means for solving the subject]

The inventors of the present invention have found that the above-mentioned problems can be solved by the following invention. That is, the present invention relates to the following [1] to [9]. [1] A protective film forming sheet having a laminated structure of a curable resin film (x) and a supporting sheet (Y), the protective film forming sheet being used to form a protective film (X) on a bump forming surface of a semiconductor wafer having a plurality of bumps and satisfying the following requirements (α1) to (α2), and satisfying the following requirements (β1) to (β3). Requirement (α1): The width ( _BMw ) of the aforementioned bump (unit: μm) is 20 μm to 350 μm.・Requirement (α2): The bump pitch (BM _P ) (unit: μm) and the bump width (BM _w ) (unit: μm) satisfy the following formula (I).・Requirement (β1): The tensile modulus E'(23°C) of the protective film (X) formed by curing the curable resin film (x) at 23°C is 1×10 ⁷ Pa to 1×10 ¹⁰ Pa. ・Requirement (β2): The tensile modulus E'(260°C) of the protective film (X) formed by curing the curable resin film (x) at 260°C is 1×10 ⁵ Pa to 1×10 ⁸ Pa. ・Requirement (β3): The thickness (XT) (unit: μm) of the protective film (X) formed by curing the curable resin film ( _x ) at 23°C and the height ( _BMh ) (unit: μm) of the bump satisfy the following formula (II). [2] The protective film forming sheet as described in [1], wherein the sheet further satisfies the following requirement (α3a); Requirement (α3a): the height (BM _h ) of the bump and the width (BM _w ) of the bump satisfy the following formula (IIIa): [3] The protective film forming sheet as described in [1], further satisfying the following requirement (α3b); Requirement (α3b): the height (BM _h ) of the bump and the width (BM _w ) of the bump satisfy the following formula (IIIb): [4] A protective film forming sheet as in any one of [1] to [3], wherein the following requirement (α4) is further satisfied; Requirement (α4): the height (BM _h ) of the bump is 15 μm to 300 μm [5] A protective film forming sheet as in any one of claims [1] to [4], wherein the support sheet (Y) is a back grinding tape. [6] A method for manufacturing a semiconductor wafer with a protective film, comprising the following steps (S1) to (S3).・Step (S1): A step of preparing a semiconductor wafer having a bump forming surface on which a plurality of bumps are provided. ・Step (S2): A step of pressing a curable resin film (x) of a protective film forming sheet as described in any one of claims 1 to 5 as an attachment surface onto the aforementioned bump forming surface of the aforementioned semiconductor wafer and attaching the same. ・Step (S3): A step of curing the curable resin film (x) to form a protective film (X). In the aforementioned step (S1), the aforementioned semiconductor wafer prepared satisfies the following requirements (α1) to (α2).・Condition (α1): The width of the bump ( _BMw ) (unit: μm) is 20μm to 350μm ・Condition (α2): The pitch of the bump ( _BMp ) (unit: μm) and the width of the bump ( _BMw ) (unit: μm) satisfy the following formula (I): [7] A method for manufacturing a semiconductor chip with a protective film, comprising the following steps (T1) to (T2). ・Step (T1): A step of obtaining a semiconductor wafer with a protective film by implementing the manufacturing method of [6]. ・Step (T2): A step of singulating the semiconductor wafer with a protective film. [8] A method for manufacturing a semiconductor package, comprising the following steps (U1) to (U2). ・Step (U1): A step of obtaining a semiconductor chip with a protective film by implementing the manufacturing method of [7]. ・Step (U2): A step of electrically connecting a wiring substrate and the semiconductor chip with a protective film via the bump. [9] The method for manufacturing a semiconductor package as in [8] further comprises a step (U3).・Step (U3): A step of filling the bottom filling material between the wiring substrate and the semiconductor chip with the protective film. [Effect of the invention]

According to the present invention, a protective film forming sheet can be provided, which can suppress short circuits between bumps with narrowed pitches.

In this specification, "active ingredient" means a component after removing a diluent such as water or an organic solvent from the components contained in the composition of interest. In addition, in this specification, "(meth)acrylic acid" means both "acrylic acid" and "methacrylic acid", and other similar terms are the same. In addition, in this specification, the weight average molecular weight and the number average molecular weight are polystyrene conversion values measured by gel permeation chromatography (GPC). In addition, in this specification, regarding the preferred numerical range (for example, the range of content, etc.), the lower limit value and the upper limit value described in stages can be combined independently. For example, from the record "10~90 is preferred, 30~60 is preferred", "preferably the lower limit value (10)" and "preferably the upper limit value (60)" can be combined to create "10~60".

[Profile of the protective film forming sheet] The protective film forming sheet of the present invention has a laminated structure of a curable resin film (x) and a supporting sheet (Y). The protective film forming sheet of the present invention is used to form a protective film (X) on the bump forming surface of a semiconductor wafer having a plurality of bumps and satisfying the following requirements (α1) to (α2). ・Requirement (α1): The width ( _BMw ) (unit: μm) of the aforementioned bump is 20μm to 350μm. ・Requirement (α2): The pitch ( _BMp ) (unit: μm) of the aforementioned bump and the width ( _BMw ) (unit: μm) of the aforementioned bump satisfy the following formula (I). Furthermore, the protective film forming sheet of the present invention satisfies the following requirements (β1) to (β3). ・Requirement (β1): The protective film (X) formed by curing the curable resin film (x) has a tensile elastic modulus E'(23°C) of 1×10 ⁷ Pa to 1×10 ¹⁰ Pa at 23°C. ・Requirement (β2): The protective film (X) formed by curing the curable resin film (x) has a tensile elastic modulus E'(260°C) of 1×10 ⁵ Pa to 1×10 ⁸ Pa at 260°C.・Requirement (β3): The thickness (XT) (unit: μm) of the protective film (X) formed by curing the curable resin film ( _x ) at 23°C and the height ( _BMh ) (unit: μm) of the bump satisfy the following formula (II).

That is, the protective film forming sheet of the present invention is used for the bump forming surface of a semiconductor wafer having bumps with narrow pitches satisfying the above requirements (α1) to (α2). Furthermore, the protective film forming sheet of the present invention specifically comprises a laminated structure of a curable resin film (x) and a support sheet (Y), and satisfies the above requirements (β1) to (β3) regarding the curable resin film (x).

The inventors of the present invention have found that by using a protective film forming sheet having a laminated structure of a curable resin film (x) and a support sheet (Y) and satisfying the above-mentioned requirements (β1) to (β3) regarding the curable resin film (x), a protective film (X) is formed on the bump forming surface of a semiconductor wafer having narrow-pitch bumps satisfying the above-mentioned requirements (α1) to (α2), thereby suppressing the collapse and deformation of the bumps and suppressing short circuits between the narrow-pitch bumps. The following describes the above-mentioned requirements (β1) to (β3) regarding the protective film (X) specified in the protective film forming sheet of the present invention.

<Requirement (β1)> Requirement (β1) stipulates that the tensile modulus E'(23℃) of the protective film (X) formed by curing the curable resin film (x) at 23℃ is 1×10 ⁷ Pa to 1×10 ¹⁰ Pa. If the tensile modulus E'(23℃) is less than 1×10 ⁷ Pa, there is a concern that the protective film (X) cannot suppress the collapse and deformation of the bumps, and the bumps may contact each other and short-circuit. On the other hand, if the tensile modulus E'(23℃) exceeds 1×10 ¹⁰ Pa, the stress during heating and cooling becomes high, which will cause a load on the bumps and reduce reliability. Here, from the viewpoint of making it easier to suppress the collapse and deformation of the bump and suppressing the load on the bump during heating and cooling, the tensile modulus E' (23°C) of the protective film (X) formed by curing the curable resin film (x) at 23°C is preferably 3×10 ⁷ Pa to 8×10 ⁹ Pa, more preferably 5×10 ⁷ Pa to 7×10 ⁹ Pa, and even more preferably 7×10 ⁷ Pa to 6×10 ⁹ Pa. The protective film (X) having the tensile modulus E' (23°C) specified in the requirement (β1) is formed by curing the curable resin film (x). The preparation method of the curable resin film (x) for forming the protective film (X) is described below.

<Requirement (β2)> Requirement (β2) stipulates that the tensile modulus E'(260°C) of the protective film (X) formed by curing the curable resin film (x) at 260°C is 1×10 ⁵ Pa to 1×10 ⁸ Pa. If the tensile modulus E'(260°C) is less than 5×10 ⁵ Pa, there is a concern that the protective film (X) cannot suppress the collapse and deformation of the bumps, and the bumps may contact each other and cause a short circuit, especially in the heating temperature range (e.g., 250°C to 270°C) in the step of electrically bonding a wiring substrate and a semiconductor wafer having bumps via the bumps. On the other hand, if the tensile modulus E'(260°C) exceeds 5×10 ⁷ Pa, stress during heating and cooling becomes high and a load is applied to the bump, resulting in reduced reliability and bonding. Here, from the viewpoint of making it easier to suppress the collapse and deformation of the bump and suppressing the load on the bump during heating and cooling, the tensile modulus E'(260°C) of the protective film (X) formed by curing the curable resin film (x) at 260°C is preferably 7×10 ⁵ Pa~3×10 ⁷ Pa, more preferably 9×10 ⁵ Pa~2×10 ⁷ Pa, and even more preferably 1×10 ⁶ Pa~1.5×10 ⁷ Pa. Furthermore, the protective film (X) having the tensile elastic modulus E' (260°C) specified in the requirement (β2) is formed by curing the curable resin film (x). The method for preparing the curable resin film (x) for forming the protective film (X) is described below.

<Requirement (β3)> Requirement (β3) defines the relationship between the thickness (XT) (unit: μm) of the protective film (X) formed by curing the curable resin film ( _x ) at 23°C and the height ( _BMh ) (unit: μm) of the bump. Specifically, the following formula (II) is satisfied. If [( _XT )/( _BMh )] < 0.2, the covering height of the protective film (X) is insufficient for the height ( _BMh ) of the bump, and there is a concern that the protective film (X) cannot suppress the collapse and deformation of the bump, and the bumps may contact each other and short-circuit. The upper limit of [( _XT )/( _BMh )] is not particularly limited, but from the viewpoint of causing the top of the bump to be exposed from the protective film (X), it is preferably 1.0 or less, and more preferably less than 1.0. Here, from the viewpoint of making it easier to suppress the collapse and deformation of the bump, and from the viewpoint of causing the top of the bump to be exposed from the protective film (X), the requirement (β3) preferably satisfies the following formula (IIa).

In formula (IIa), P is 0.2, preferably 0.30, more preferably 0.40, and more preferably 0.50. In formula (IIa), Q is preferably 1.0, more preferably 0.90, and more preferably 0.80.

Furthermore, the thickness of the curable resin film (x) satisfying the relationship specified in requirement (β3) can be adjusted based on the relationship between the thickness of the curable resin film (x) and the thickness of the protective film (X) formed by curing the curable resin film (x), and information such as the height of the bumps possessed by the semiconductor wafer to be used. FIG11 shows the relationship between the height of the bump (BM _h ) and the thickness (XT) (unit: μm) of the protective film (X) formed by curing the curable resin film ( _x ) at 23°C. The thickness (XT) (unit: μm) of the protective film (X) formed by curing the curable resin film ( _x ) at 23°C means the height of the bump (bump _BM ) at the position 50 farthest from the bump forming surface 41a in the contact portion between the bump and the protective film (X) as shown in FIG11. However, the position 50 farthest from the bump forming surface 41a is determined within the region where the protective film (X) formed on the bump forming surface 41a continuously exists. Therefore, for example, the position 50 farthest from the bump forming surface 41a is not determined from the contact portion between the protective film (X) which is partially present on the top of the bump and is removed by the exposure treatment (plasma etching treatment) described later and the bump. Furthermore, in the case of performing the exposure treatment (plasma etching treatment) described later, the thickness of the protective film (X) after the exposure treatment must satisfy the above formula (II) (0.2 μm or more). That is, regardless of whether the exposure treatment described later is performed or not, the thickness of the protective film (X) must satisfy the above formula (II) (0.2 μm or more) just before the step of electrically connecting the semiconductor chip and the wiring substrate via the spherical bump. The height of the bump (BM _h ) and the thickness of the protective film (X) ( _XT ) can be measured, for example, by cutting a semiconductor wafer with the protective film (X) in a direction perpendicular to the bump formation surface and passing through the center of the bump, and observing the cut cross section with an optical microscope.

Hereinafter, the protective film-forming sheet of the present invention will be described in detail with reference to a method for preparing a curable resin film (x) for forming a protective film (X) satisfying the requirements (β1) and (β2).

<<Constitution of the protective film forming sheet>> An example of the constitution of the protective film forming sheet of the present invention is shown in FIG1. A protective film forming sheet of one embodiment of the present invention is a protective film forming sheet 1 shown in FIG1, wherein a curable resin film (x) is provided on one side of a support sheet (Y). By providing the curable resin film (x) on one side of the support sheet (Y), the curable resin film (x) is stably supported and protected when the curable resin film (x) is transported as a product package or when the curable resin film (x) is transported within a step.

In addition, an example of the structure of a protective film forming sheet of one embodiment of the present invention is shown in Figures 2 to 4. The protective film forming sheet of one embodiment of the present invention is a protective film forming sheet 1a as shown in Figure 2, and the supporting sheet (Y) is a substrate 11, and a curable resin film (x) is provided on one side of the substrate 11. In addition, a protective film forming sheet of one embodiment of the present invention is a protective film forming sheet 1b as shown in Figure 3, and the supporting sheet (Y) is an adhesive sheet formed by laminating the substrate 11 and the adhesive layer 21, and the adhesive layer 21 of the adhesive sheet and the curable resin film (x) can also be bonded. In addition, the protective film forming sheet of one aspect of the present invention is a protective film forming sheet 1c shown in FIG4, wherein the support sheet (Y) is an adhesive sheet formed by laminating the substrate 11, the intermediate layer 31, and the adhesive layer 21 in the order of the substrate 11, the intermediate layer 31, and the adhesive layer 21 of the adhesive sheet and the curable resin film (x) can also be laminated. The adhesive sheet formed by laminating the substrate 11, the intermediate layer 31, and the adhesive layer 21 in the order of the substrate 11 can be suitably used as a back grinding tape. That is, since the protective film forming sheet 1c shown in FIG. 4 has a back grinding tape as a supporting sheet (Y), it can be suitably used in the case of grinding the surface opposite to the bump forming surface of the semiconductor wafer (hereinafter, also referred to as the "back side of the semiconductor wafer") to thin the semiconductor wafer after the curable resin film (x) of the protective film forming sheet 1c is bonded to the bump forming surface of the semiconductor wafer having a plurality of bumps.

Hereinafter, the curable resin film (x) and the supporting sheet (Y) used in the protective film-forming sheet of the present invention will be described.

<<Curing resin film (x)>> The curing resin film (x) is a film used to protect the bump forming surface of a semiconductor wafer having a plurality of bumps, and is formed into a protective film (X) by curing by heating or energy ray irradiation. That is, the curing resin film (x) can be a thermosetting resin film (x1) that is cured by heating, or an energy ray curing resin film (x2) that is cured by energy ray irradiation. In addition, in this specification, "energy ray" means an energy quanta in an electromagnetic wave or a charged particle beam. As examples thereof, ultraviolet rays, electron beams, etc. can be cited, and ultraviolet rays are preferably cited.

The physical properties of the curable resin film (x) can be adjusted by adjusting either or both of the type and amount of the components contained in the curable resin film (x).

The following describes the thermosetting resin film (x1) and the energy ray-curing resin film (x2).

<Thermosetting resin film (x1)> Thermosetting resin film (x1) contains a polymer component (A) and a thermosetting component (B). Thermosetting resin film (x1) is formed, for example, by a thermosetting resin composition (x1-1) containing a polymer component (A) and a thermosetting component (B). The polymer component (A) is a component formed by a polymerization reaction of a polymerizable compound. In addition, the thermosetting component (B) is a component that can undergo a curing (polymerization) reaction using heat as a reaction trigger. Moreover, the curing (polymerization) reaction also includes a condensation polymerization reaction. Furthermore, in the following descriptions of this specification, "the content of each component in the total amount of effective components of the thermosetting resin composition (x1-1)" is synonymous with "the content of each component in the thermosetting resin film (x1) formed by the thermosetting resin composition (x1-1)".

(Polymer component (A)) The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) contain a polymer component (A). The polymer component (A) is a polymer compound for imparting film-forming properties or flexibility to the thermosetting resin film (x1). The polymer component (A) may be used alone or in combination of two or more. When two or more polymer components (A) are used in combination, the combination and ratio may be arbitrarily selected.

As the polymer component (A), for example, polyvinyl acetal, acrylic resin (resin having a (meth)acryl group), polyester, urethane resin (resin having a urethane bond), acrylic urethane resin, silicone resin (resin having a siloxane bond), rubber resin (resin having a rubber structure), phenoxy resin, and thermosetting polyimide can be cited. These can be used alone or in combination of two or more. Among them, one or more selected from polyvinyl acetal and acrylic resin is preferred. The following description is given by taking polyvinyl acetal and acrylic resin as preferred polymer components (A) as examples.

・Polyvinyl acetal The polyvinyl acetal used as the polymer component (A) is not particularly limited, and for example, a known polyvinyl acetal can be used. Here, among the polyvinyl acetals, for example, polyvinyl formaldehyde, polyvinyl butyral, etc. can be cited, and polyvinyl butyral is preferred. As polyvinyl butyral, from the viewpoint of improving the adhesion between the bump formation surface of the semiconductor wafer and the protective film (X), it is preferred to have the constituent units represented by the following formulas (i-1), (i-2), and (i-3).

In the above formulae (i-1), (i-2), and (i-3), p, q, and r are the content ratios (mol %) of the respective constituent units.

The weight average molecular weight (Mw) of polyvinyl acetal is preferably 5,000-200,000, more preferably 8,000-100,000, more preferably 9,000-80,000, and even more preferably 10,000-50,000. When the weight average molecular weight of polyvinyl acetal is within this range, the adhesion between the bump forming surface of the semiconductor wafer and the protective film (X) is easily improved. In addition, the effect of suppressing the residual protective film (X) on the upper part of the bump (the top of the bump and the area near it) becomes higher.

The content ratio p (butyralization degree) of the constituent units of the butyraldehyde group represented by the above formula (i-1) is preferably 40 to 90 mol %, more preferably 50 to 85 mol %, and even more preferably 60 to 76 mol %, based on the total constituent units of the polymer component (A).

The content ratio q of the constituent unit having an acetyl group represented by the above formula (i-2) is preferably 0.1 to 9 mol %, more preferably 0.5 to 8 mol %, and even more preferably 1 to 7 mol %, based on the total constituent units of the polymer component (A).

The content ratio r of the constituent unit having a hydroxyl group represented by the above formula (i-3) is preferably 10 to 60 mol %, more preferably 10 to 50 mol %, and even more preferably 20 to 40 mol %, based on the total constituent units of the polymer component (A).

The glass transition temperature (Tg) of polyvinyl acetal is preferably 40-80°C, more preferably 50-70°C. When the Tg of polyvinyl acetal is within this range, when the thermosetting resin film (x1) is attached to the bump forming surface of the wafer with bumps, the effect of suppressing the residual protective film (X) on the upper part of the bumps becomes higher, and the hardness of the protective film formed by thermally curing the thermosetting resin layer can be made sufficient. In addition, in this specification, the glass transition temperature (Tg) of the polymer (resin) is a value measured by the method described in the embodiment described later.

The content ratio of the above three constituent units constituting polyvinyl butyral can be arbitrarily adjusted according to the desired physical properties. In addition, polyvinyl butyral may also have constituent units other than the above three constituent units. The content of the above three constituent units is preferably 80-100 mol%, preferably 90-100 mol%, and more preferably 100 mol%, based on the total amount of polyvinyl butyral.

・Acrylic resin As the acrylic resin, there can be cited well-known acrylic polymers. The weight average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000. When the weight average molecular weight of the acrylic resin is above the above lower limit, the shape stability (time stability during storage) of the thermosetting resin film (x1) can be easily improved. Furthermore, when the weight average molecular weight of the acrylic resin is below the above upper limit, the thermosetting resin film (x1) can easily follow the uneven surface of the adherend, for example, it is easy to suppress the occurrence of voids between the adherend and the thermosetting resin film (x1).

The glass transition temperature (Tg) of the acrylic resin is preferably -60~70℃, and more preferably -30~50℃. When the glass transition temperature (Tg) of the acrylic resin is above the lower limit, the adhesion between the protective film (X) and the support sheet (Y) is suppressed, and the peeling property of the support sheet (Y) is improved. In addition, when the glass transition temperature (Tg) of the acrylic resin is below the upper limit, the adhesion between the thermosetting resin film (x1) and the protective film (X) and the adherend is improved.

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

Examples of the (meth)acrylates constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, 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, 2-oct ... Ester, 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), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate), etc., the alkyl group constituting the alkyl ester is a chain structure of alkyl (meth)acrylate with a carbon number of 1 to 18; Cycloalkyl (meth)acrylates such as isoborneol (meth)acrylate and dicyclopentanyl (meth)acrylate; Aryl (meth)acrylates such as benzyl (meth)acrylate; Cycloalkyl (meth)acrylates such as dicyclopentenyl (meth)acrylate; Cycloalkyl (meth)acrylates such as dicyclopentenyl (meth)acrylate; Cycloalkyl (meth)acrylates such as dicyclopentenyl (meth)acrylate; Cycloalkyl (meth)acrylates such as dicyclopentenyloxyethyl (meth)acrylate; Amido (meth)acrylate; Glycyrrhetinyl (meth)acrylates such as glycyrrhetinyl (meth)acrylate; (Meth)acrylates containing hydroxyl groups such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; (meth)acrylates containing substituted amino groups such as N-methylaminoethyl (meth)acrylate, etc. In this specification, "substituted amino group" means a group in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom.

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

The monomers constituting the acrylic resin may be a single type or two or more types. When the monomers constituting the acrylic resin are two or more types, the combination and ratio thereof may be arbitrarily selected.

The acrylic resin may also have functional groups such as vinyl, (meth)acryl, amino, hydroxyl, carboxyl, and isocyanate that can bond with other compounds. The aforementioned functional groups of the acrylic resin can bond with other compounds via the crosslinking agent (F) described below, or can directly bond with other compounds without the crosslinking agent (F). Since the acrylic resin bonds with other compounds via the aforementioned functional groups, the reliability of the package obtained by using the thermosetting resin film (x1) tends to be improved.

・Other resins Here, in one aspect of the present invention, instead of using an acrylic resin, a thermoplastic resin other than polyvinyl acetal and an acrylic resin (hereinafter, simply referred to as "thermoplastic resin") may be used alone as the polymer component (A), or it may be used in combination with polyvinyl acetal and/or an acrylic resin. By using a thermoplastic resin, the peeling property of the protective film (X) from the supporting sheet (Y) is improved, the thermosetting resin film (x1) becomes easier to follow the uneven surface of the adherend, and the generation of voids between the adherend and the thermosetting resin film (x1) is further suppressed.

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

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

As the thermoplastic resin, there can be cited, for example, polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

The thermoplastic resin may be used alone or in combination of two or more. When two or more thermoplastic resins are used, the combination and ratio thereof may be arbitrarily selected.

・Content of polymer component (A) From the perspective of easily obtaining a protective film (X) that satisfies requirements (β1) and (β2), the content of polymer component (A) is preferably 5 to 85 mass %, more preferably 10 to 80 mass %, more preferably 15 to 70 mass %, more preferably 15 to 60 mass %, and even more preferably 15 to 50 mass %, based on the total amount of the effective components of the thermosetting resin composition (x1-1).

・Preferred aspects of polymer component (A) As described above, as polymer component (A), it is preferred to select at least one selected from polyvinyl acetal and acrylic resin. From the perspective of easily obtaining a protective film (X) that satisfies requirements (β1) and (β2), polymer component (A) is preferably polyvinyl acetal. Moreover, polymer component (A) may also correspond to thermosetting component (B). In the present invention, when thermosetting resin composition (x1-1) contains such a component corresponding to both polymer component (A) and thermosetting component (B), thermosetting resin composition (x1-1) is regarded as containing both polymer component (A) and thermosetting component (B).

(Thermosetting component (B)) The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) contain a thermosetting component (B). The thermosetting component (B) is a component used to form a hard protective film (X) from the thermosetting resin film (x1). The thermosetting component (B) can be used alone or in combination of two or more. When there are two or more thermosetting components (B), the combination and ratio of the components can be arbitrarily selected.

Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyimide, polyurethane, unsaturated polyester, and silicone resins, among which epoxy-based thermosetting resins are preferred.

The epoxy-based thermosetting resin is composed of an epoxy resin (B1) and a thermosetting agent (B2). The epoxy-based thermosetting resin may be used alone or in combination of two or more. When there are two or more epoxy-based thermosetting resins, the combination and ratio thereof may be selected arbitrarily.

・Epoxy resin (B1) As the epoxy resin (B1), known ones can be cited, for example, polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydride, o-cresol novolac epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin, and epoxy compounds having two or more functional groups can be cited.

As the epoxy resin (B1), an epoxy resin having an unsaturated hydrocarbon group can be used. An epoxy resin having an unsaturated hydrocarbon group has a 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 the package obtained by using the thermosetting resin film (x1) is improved.

As an epoxy resin having an unsaturated hydrocarbon group, for example, a compound in which a part of the epoxy groups of a multifunctional epoxy resin is converted into a group having an unsaturated hydrocarbon group can be cited. Such a compound is obtained, for example, by subjecting an epoxy group to an addition reaction with (meth) acrylic acid or a derivative thereof. Furthermore, as an epoxy resin having an unsaturated hydrocarbon group, for example, a compound in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring constituting the epoxy resin can be cited. The unsaturated hydrocarbon group is an unsaturated group having polymerizability, and specific examples thereof include vinyl (vinyl), 2-propenyl (allyl), (meth)acrylamide, and (meth)acrylamide. Among these, acryl is preferred.

The number average molecular weight of the epoxy resin (B1) is not particularly limited. From the perspective of the curability of the thermosetting resin film (x1) and the strength and heat resistance of the cured protective film (X), it is preferably 300-30,000, more preferably 400-10,000, and even more preferably 500-3,000. The epoxy equivalent of the epoxy resin (B1) is preferably 100-1,000 g/eq, and more preferably 300-800 g/eq.

The epoxy resin (B1) may be used alone or in combination of two or more. When two or more epoxy resins (B1) are used in combination, the combination and ratio may be arbitrarily selected.

・Thermosetting agent (B2) Thermosetting agent (B2) functions as a hardener for epoxy resin (B1). As the thermosetting agent (B2), for example, a compound having two or more functional groups that can react with an epoxy group in one molecule can be cited. As the functional group, for example, a phenolic hydroxyl group, an alcoholic hydroxyl group, an amine group, a carboxyl group, and an acid group anhydride-treated group can be cited. A phenolic hydroxyl group, an amine group, or an acid group anhydride-treated group is preferred, and a phenolic hydroxyl group or an amine group is more preferred.

Among the thermosetting agents (B2), examples of phenolic curing agents having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac phenolic resins, dicyclopentadiene phenolic resins, and aralkyl phenolic resins. Among the thermosetting agents (B2), examples of amine curing agents having an amine group include dicyandiamide (hereinafter, abbreviated as "DICY"), etc.

Thermosetting agent (B2) may also be one having an unsaturated hydrocarbon group. As the thermosetting agent (B2) having an unsaturated hydrocarbon group, for example, there can be cited a compound in which a part of the hydroxyl group of a phenol resin is replaced by a group having an unsaturated hydrocarbon group, or a compound in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of a phenol resin. The unsaturated hydrocarbon group mentioned above in the thermosetting agent (B2) is the same as the unsaturated hydrocarbon group in the above-mentioned epoxy resin having an unsaturated hydrocarbon group.

When a phenolic curing agent is used as the thermosetting agent (B2), from the viewpoint of facilitating the peeling property of the protective film (X) from the supporting sheet (Y), the thermosetting agent (B2) preferably has a high softening point or glass transition temperature.

The number average molecular weight of the resin components of the thermosetting agent (B2), for example, multifunctional phenol resins, novolac phenol resins, dicyclopentadiene phenol resins, and aralkyl phenol resins, is preferably 300 to 30,000, more preferably 400 to 10,000, and even more preferably 500 to 3,000. The molecular weight of the non-resin components of the thermosetting agent (B2), for example, biphenol, dicyandiamide, etc., is not particularly limited, and is preferably 60 to 500, for example.

The thermosetting agent (B2) may be used alone or in combination of two or more. When two or more thermosetting agents (B2) are used, the combination and ratio thereof may be arbitrarily selected.

In the thermosetting resin composition (x1-1), the content of the thermosetting agent (B2) is preferably 0.1 to 500 parts by mass, and more preferably 1 to 200 parts by mass, relative to 100 parts by mass of the epoxy resin (B1). When the content of the thermosetting agent (B2) is above the lower limit, the curing of the thermosetting resin film (x1) becomes easier. In addition, when the content of the thermosetting agent (B2) is below the upper limit, the moisture absorption rate of the thermosetting resin film (x1) is reduced, and the reliability of the package obtained using the thermosetting resin film (x1) is further improved.

In the thermosetting resin composition (x1-1), the content of the thermosetting component (B) (the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is preferably 50 to 1000 parts by mass, preferably 70 to 800 parts by mass, more preferably 80 to 600 parts by mass, more preferably 90 to 500 parts by mass, and even more preferably 100 to 400 parts by mass relative to 100 parts by mass of the content of the polymer component (A). When the content of the thermosetting component (B) is within this range, the adhesion between the protective film (X) and the supporting sheet (Y) is suppressed, and the releasability of the supporting sheet (Y) is improved. In addition, a protective film (X) that satisfies the requirements (β1) and (β2) can be easily obtained. Furthermore, the more the amount of the thermosetting component (B) relative to the polymer component (A) increases, the more the tensile modulus E' tends to increase. Conversely, the less the amount of the thermosetting component (B) relative to the polymer component (A) decreases, the more the tensile modulus E' tends to decrease.

(Hardening accelerator (C)) The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may also contain a hardening accelerator (C). The hardening accelerator (C) is a component for adjusting the hardening speed of the thermosetting resin composition (x1-1). Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles (imidazoles in which one or more hydrogen atoms are replaced by groups other than hydrogen atoms) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines (phosphines in which one or more hydrogen atoms are replaced by organic groups) such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylborates such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

The hardening accelerator (C) may be used alone or in combination of two or more. When two or more hardening accelerators (C) are used, the combination and ratio thereof may be arbitrarily selected.

In the thermosetting resin composition (x1-1), the content of the curing accelerator (C) when using the curing accelerator (C) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the content of the thermosetting component (B). When the content of the curing accelerator (C) is above the above lower limit, the effect obtained by using the curing accelerator (C) can be more significantly achieved. Furthermore, by keeping the content of the curing accelerator (C) below the above-mentioned upper limit, for example, under high temperature and high humidity conditions, the effect of suppressing the migration and segregation of the highly polar curing accelerator (C) in the thermosetting resin film (x1) to the bonding interface side with the adherend is enhanced, and the reliability of the package obtained using the thermosetting resin film (x1) is further improved.

(Filler (D)) The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may also contain a filler (D). By containing the filler (D), it becomes easier to adjust the thermal expansion coefficient of the protective film (X) obtained by curing the thermosetting resin film (x1) to an appropriate range, and the reliability of the package obtained using the thermosetting resin film (x1) is further improved. In addition, by containing the filler (D), the thermosetting resin film (x1) can also reduce the moisture absorption rate of the protective film (X) and improve the heat dissipation.

The filler (D) may be any of an organic filler and an inorganic filler, and an inorganic filler is preferred. Preferred inorganic fillers include, for example, powders of silicon dioxide, alumina, talc, calcium carbonate, titanium dioxide, red iron oxide (Bengala), silicon carbide, boron nitride, etc.; beads obtained by sphericalizing the inorganic fillers; surface-modified products of the inorganic fillers; single crystal fibers of the inorganic fillers; glass fibers, etc. Among the inorganic fillers, silicon dioxide or alumina is preferred.

The filler (D) may be used alone or in combination of two or more. When there are two or more fillers (D), the combination and ratio thereof may be selected arbitrarily.

When the filler (D) is used, the content of the filler (D) is preferably 5 to 80% by mass, more preferably 7 to 60% by mass, based on the total amount of the effective components of the thermosetting resin composition (x1-1). When the content of the filler (D) is within this range, it becomes easier to adjust the above-mentioned thermal expansion coefficient.

The average particle size of the filler (D) is preferably 5nm~1,000nm, more preferably 5nm~500nm, and even more preferably 10nm~300nm. The above average particle size is the average value of the outer diameter of a particle measured at multiple locations.

(Coupling agent (E)) The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may also contain a coupling agent (E). By using a coupling agent (E) having a functional group that can react with an inorganic compound or an organic compound, the adhesion and tightness of the thermosetting resin film (x1) to the adherend can be easily improved. In addition, by using a coupling agent (E), the heat resistance of the protective film (X) obtained by curing the thermosetting resin film (x1) will not be impaired, and the water resistance can be easily improved.

The coupling agent (E) is preferably a compound having a functional group that can react with the functional groups of the polymer component (A) and the thermosetting component (B), and a silane coupling agent is more preferred. Preferred silane coupling agents include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, and the like. )propyl trimethoxysilane, 3-(2-aminoethylamino)propyl methyldiethoxysilane, 3-(phenylamino)propyl trimethoxysilane, 3-anilinopropyl trimethoxysilane, 3-ureidopropyl triethoxysilane, 3-butylenepropyl trimethoxysilane, 3-butylenepropyl methyldimethoxysilane, bis(3-triethoxysilylpropyl) tetrasulfane, methyl trimethoxysilane, methyl triethoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane, and imidazole silane.

The coupling agent (E) may be used alone or in combination of two or more. When there are two or more coupling agents (E), the combination and ratio thereof may be arbitrarily selected.

In the thermosetting resin composition (x1-1), the content of the coupling agent (E) when the coupling agent (E) is used is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the total content of the polymer component (A) and the thermosetting component (B). When the content of the coupling agent (E) is above the lower limit, the effects of using the coupling agent (E), such as improving the dispersibility of the filler (D) in the resin or improving the adhesion of the thermosetting resin film (x1) to the adherend, can be more significantly achieved. In addition, when the content of the coupling agent (E) is below the upper limit, the generation of released gas can be further suppressed.

(Crosslinking agent (F)) When the above-mentioned acrylic resin or the like having a functional group such as a vinyl group, a (meth)acryl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group that can bond with other compounds is used as the polymer component (A), the thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may also contain a crosslinking agent (F) for crosslinking the aforementioned functional group with other compounds. By crosslinking with the crosslinking agent (F), the initial adhesion and cohesion of the thermosetting resin film (x1) can be adjusted.

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

Examples of the organic polyvalent isocyanate compound include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds and alicyclic polyvalent isocyanate compounds (hereinafter, these compounds may be collectively referred to as "aromatic polyvalent isocyanate compounds, etc."); trimers, isocyanurates and adducts of the aforementioned aromatic polyvalent isocyanate compounds, etc.; terminal isocyanate urethane prepolymers obtained by reacting the aforementioned aromatic polyvalent isocyanate compounds, etc. with a polyol compound, etc.; The aforementioned "adduct" refers to the reaction product of the aforementioned aromatic polyvalent isocyanate compound, aliphatic polyvalent isocyanate compound or alicyclic polyvalent isocyanate compound with a low molecular weight active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trihydroxymethylpropane or castor oil, and examples thereof include the xylene diisocyanate adduct of trihydroxymethylpropane.

More specifically, the organic polyvalent isocyanate compound includes, for example, 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylene diisocyanate; diisocyanate); diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; any one or more compounds of toluene diisocyanate, hexamethylene diisocyanate and xylene diisocyanate added to all or part of the hydroxyl groups of polyols such as trihydroxymethylpropane; lysine diisocyanate, etc.

Examples of the organic polyvalent imine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trihydroxymethylpropane-tri-β-aziridine propionate, tetrahydroxymethylmethane-tri-β-aziridine propionate, and N,N'-toluene-2,4-bis(1-aziridinecarboxamide)triethylmelamine.

When an organic polyvalent isocyanate compound is used as the crosslinking agent (F), it is preferred 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 crosslinking structure can be easily introduced into the thermosetting resin film (x1) by the reaction between the crosslinking agent (F) and the polymer component (A).

The crosslinking agent (F) may be used alone or in combination of two or more. When two or more crosslinking agents (F) are used, the combination and ratio thereof may be arbitrarily selected.

In the thermosetting resin composition (x1-1), when the crosslinking agent (F) is used, the content of the crosslinking agent (F) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the content of the polymer component (A). When the content of the crosslinking agent (F) is above the lower limit, the effect obtained by using the crosslinking agent (F) can be more significantly obtained. In addition, when the content of the crosslinking agent (F) is below the upper limit, excessive use of the crosslinking agent (F) can be suppressed.

(Energy ray curing resin (G)) Thermosetting resin film (x1) and thermosetting resin composition (x1-1) may also contain energy ray curing resin (G). Thermosetting resin film (x1) can change its properties due to irradiation with energy rays by containing energy ray.

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

Examples of the acrylate compound include trihydroxymethylpropane tri(meth)acrylate, tetrahydroxymethylmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxy penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and the like. (meth)acrylates having a (meth) skeleton; (meth)acrylates having a cyclic aliphatic skeleton such as dicyclopentyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates; urethane (meth)acrylate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the aforementioned polyalkylene glycol (meth)acrylates; itaconic acid oligomers, etc.

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

The energy ray-curable compound used for polymerization may be used alone or in combination of two or more. When two or more energy ray-curable compounds are used for polymerization, the combination and ratio thereof may be arbitrarily selected.

When the energy ray curing resin (G) is used, the content of the energy ray curing resin (G) is preferably 1 to 95 mass %, more preferably 5 to 90 mass %, and even more preferably 10 to 85 mass %, based on the total amount of the active ingredients in the thermosetting resin composition (x1-1).

(Photopolymerization initiator (H)) When the thermosetting resin film (x1) and the thermosetting resin composition (x1-1) contain the energy ray-curing resin (G), the thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may also contain a photopolymerization initiator (H) in order to efficiently perform the polymerization reaction of the energy ray-curing resin (G).

Examples of the photopolymerization initiator (H) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin benzoic acid methyl, benzoin dimethyl ketal, 2,4-diethylthione, 1-hydroxycyclohexylphenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, 1,2-diphenylmethane, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2,4,6-trimethylbenzyldiphenylphosphine oxide, and 2-chloroanthraquinone.

The photopolymerization initiator (H) may be used alone or in combination of two or more. When two or more photopolymerization initiators (H) are used, the combination and ratio thereof may be arbitrarily selected.

In the thermosetting resin composition (x1-1), the content of the photopolymerization initiator (H) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass, relative to 100 parts by mass of the energy ray-curable resin (G).

(General-purpose additive (I)) The thermosetting resin film (x1) and the thermosetting resin composition (x1-1) may also contain a general-purpose additive (I) within the scope of not impairing the effect of the present invention. The general-purpose additive (I) is well-known and can be arbitrarily selected according to the purpose without particular limitation. Preferred general-purpose additives (I) include, for example, plasticizers, antistatic agents, antioxidants, colorants (dyes, pigments), and gettering agents, etc.

The general-purpose additive (I) may be used alone or in combination of two or more. When there are two or more general-purpose additives (I), the combination and ratio thereof may be arbitrarily selected. The content of the general-purpose additive (I) is not particularly limited and may be appropriately selected according to the purpose.

(Solvent) It is preferable that the thermosetting resin composition (x1-1) further contains a solvent. The thermosetting resin composition (x1-1) containing a solvent has good operability. The solvent is not particularly limited, and preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropane-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, etc. The solvent may be used alone or in combination of two or more. When there are two or more solvents, the combination and ratio of the solvents can be selected arbitrarily. Methyl ethyl ketone is preferred from the viewpoint of being able to more evenly mix the components contained in the thermosetting resin composition (x1-1).

(Preparation method of thermosetting resin composition (x1-1)) The thermosetting resin composition (x1-1) is prepared by blending the components constituting the composition. The order of addition of the components when blending is not particularly limited, and two or more components may be added at the same time. When using a solvent, the solvent may be mixed with any blending component other than the solvent and the blending component may be diluted in advance before use, or the solvent may be mixed with the blending components without diluting any blending component other than the solvent in advance. There is no particular limitation on the method of mixing the ingredients during blending. You can choose from the known methods such as mixing by rotating a stirring rod or a stirring blade, mixing by using a mixer, and mixing by applying ultrasound. The temperature and time for adding and mixing the ingredients are not particularly limited as long as the blending ingredients do not deteriorate. They can be adjusted appropriately. The temperature is preferably 15~30℃.

<Energy ray curable resin film (x2)> The energy ray curable resin film (x2) contains an energy ray curable component (a). The energy ray curable resin film (x2) is formed, for example, from an energy ray curable resin composition (x2-1) containing an energy ray curable component (a). The energy ray curable component (a) is preferably uncured, preferably has adhesiveness, and more preferably is uncured and has adhesiveness. In the following description of this specification, "the content of each component based on the total amount of the effective components of the energy ray curable resin composition (x2-1)" is synonymous with "the content of each component of the energy ray curable resin film (x2) formed from the energy ray curable resin composition (x2-1)".

(Energy ray curing component (a)) The energy ray curing component (a) is a component that is cured by irradiation with energy rays, and is also a component used to impart film-forming properties or flexibility to the energy ray curing resin film (x2). As the energy ray curing component (a), for example, a polymer (a1) having an energy ray curing group with a weight average molecular weight of 80,000 to 2,000,000 and a compound (a2) having an energy ray curing group with a molecular weight of 100 to 80,000 can be cited. The polymer (a1) may be one in which at least a portion is crosslinked by a crosslinking agent, or may be one that is not crosslinked.

(Polymer (a1)) As the polymer (a1) having a weight average molecular weight of 80,000 to 2,000,000 and having an energy ray-curable group, for example, an acrylic resin (a1-1) obtained by polymerizing an acrylic polymer (a11) and an energy ray-curable compound (a12), wherein the acrylic polymer (a11) has a functional group that can react with a group possessed by another compound, and the energy ray-curable compound (a12) has an energy ray-curable group having a group that reacts with the aforementioned functional group and an energy ray-curable double bond.

As functional groups that can react with groups possessed by other compounds, for example, hydroxyl groups, carboxyl groups, amino groups, substituted amino groups (groups formed by replacing one or two hydrogen atoms of an amino group with groups other than hydrogen atoms), and epoxy groups can be cited. However, in order to prevent circuit corrosion of semiconductor wafers or semiconductor chips, the functional groups are preferably groups other than carboxyl groups. Among these, the functional groups are preferably hydroxyl groups.

・Acrylic polymer (a11) having a functional group Examples of the acrylic polymer (a11) having a functional group include a copolymer of an acrylic monomer having a functional group and an acrylic monomer having no functional group, or a copolymer of these monomers and a monomer other than the acrylic monomer (non-acrylic monomer). 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 carboxyl group-containing monomer, an amino group-containing monomer, a substituted amino group-containing monomer, and an epoxy group-containing monomer.

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

Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as fumaric acid, itaconic acid, maleic acid, citric acid; anhydrides of the aforementioned ethylenically unsaturated dicarboxylic acids; (meth)acrylic acid carboxylalkyl esters such as 2-carboxyethyl methacrylate, and the like.

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

The acrylic monomer having a functional group constituting the acrylic polymer (a11) may be used alone or in combination of two or more. When there are two or more acrylic monomers having a functional group constituting the acrylic polymer (a11), the combination and ratio thereof may be arbitrarily selected.

Examples of acrylic monomers having no functional group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, 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, 2-oct ... The alkyl group constituting the alkyl esters such as isononyl (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), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate) is a chain-like structure alkyl (meth)acrylate having 1 to 18 carbon atoms.

Examples of acrylic monomers without functional groups include (meth)acrylates containing alkoxyalkyl groups such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate; (meth)acrylates containing aromatic groups such as aryl (meth)acrylate such as phenyl (meth)acrylate; non-crosslinking (meth)acrylamide and its derivatives; and non-crosslinking (meth)acrylates containing tertiary amine groups such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

The acrylic monomer having no functional group constituting the acrylic polymer (a11) may be used alone or in combination of two or more. When there are two or more acrylic monomers having no functional group constituting the acrylic polymer (a11), the combination and ratio thereof may be arbitrarily 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 used alone or in combination of two or more. When there are two or more non-acrylic monomers constituting the acrylic polymer (a11), the combination and ratio thereof may be arbitrarily selected.

In the acrylic polymer (a11), the ratio (content) of the amount of the constituent units derived from the acrylic monomer having a functional group to the total mass of the constituent units constituting the acrylic polymer (a11) is preferably 0.1 to 50 mass %, more preferably 1 to 40 mass %, and even more preferably 3 to 30 mass %. The aforementioned ratio can be easily adjusted to a preferred range by adjusting the content of the energy ray-curable group in the acrylic resin (a1-1) obtained by copolymerizing the acrylic polymer (a11) and the energy ray-curable compound (a12) within such a range to adjust the curing degree of the protective film (X) to a preferred range.

The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be used alone or in combination of two or more. When there are two or more acrylic polymers (a11) constituting the acrylic resin (a1-1), the combination and ratio thereof may be arbitrarily selected.

The content of the acrylic resin (a1-1) is preferably 1 to 60 mass %, more preferably 3 to 50 mass %, and even more preferably 5 to 40 mass %, based on the total amount of the effective components of the energy ray-curable resin composition (x2-1).

・Energy ray curing compound (a12) The energy ray curing compound (a12) preferably has one or more selected from the group consisting of isocyanate group, epoxy group, and carboxyl group as a group capable of reacting with the functional group possessed by the acrylic polymer (a11), and more preferably has an isocyanate group as the aforementioned group. For example, when the energy ray curing compound (a12) has an isocyanate group as the aforementioned group, the isocyanate group is likely to react with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the aforementioned functional group.

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

Examples of the energy ray-curable compound (a12) include 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1-(diacryloyloxymethyl)ethyl isocyanate, acryl monoisocyanate compounds obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate, and acryl monoisocyanate compounds obtained by reacting a diisocyanate compound or a polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate. 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 used alone or in combination of two or more. When the energy ray-curable compound (a12) constituting the acrylic resin (a1-1) is two or more, the combination and ratio thereof may be arbitrarily selected.

In the acrylic resin (a1-1), the ratio of the content of the energy ray curable group derived from the energy ray curable compound (a12) to the content of the aforementioned functional group derived from the acrylic polymer (a11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and even more preferably 50 to 100 mol%. When the aforementioned content ratio is within such a range, the adhesion of the protective film (X) after curing becomes greater. Moreover, when the energy ray curable compound (a12) is a monofunctional compound (having one aforementioned group in one molecule), the upper limit of the aforementioned content ratio will become 100 mol%, but when the aforementioned energy ray curable compound (a12) is a polyfunctional compound (having two or more aforementioned groups in one molecule), the upper limit of the aforementioned content ratio may exceed 100 mol%.

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

When at least a part of the polymer (a1) is crosslinked by a crosslinking agent, the polymer (a1) may be a monomer which is not required to be polymerized with any of the monomers described above as constituting the acrylic polymer (a11) and which has a group reactive with the crosslinking agent, and may be a polymer crosslinked on a group reactive with the crosslinking agent, or may be a polymer crosslinked on a group reactive with the functional group derived from the energy ray-curable compound (a12).

The polymer (a1) may be used alone or in combination of two or more. When two or more polymers (a1) are used, the combination and ratio thereof may be arbitrarily selected.

(Compound (a2)) As the energy ray-hardening group possessed by the compound (a2) having a weight average molecular weight of 100 to 80,000, a group including an energy ray-hardening double bond can be cited, and as a comparative group, a (meth)acryl group or a vinyl group can be cited.

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

Among the compounds (a2), examples of low molecular weight compounds having an energy ray-curable group include polyfunctional monomers or oligomers, and preferably acrylate compounds having a (meth)acryloyl group. Examples of acrylate compounds include 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxydiethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]propane, )phenyl]fluorene, 2,2-bis[4-((meth)acryloyloxypolypropoxy)phenyl]propane, tricyclodecanedimethanol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate , diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxyethoxy)phenyl]propane, neopentyl glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, 2-hydroxy-1,3-di(meth)acryloyloxypropane and other bifunctional (meth)acrylates; tris(2-(meth)acryloyloxyethyl)isocyanurate, ε-caprolactone-modified tris(2-(meth)acryloyloxyethyl)isocyanurate esters, ethoxylated glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trihydroxymethylpropane tri(meth)acrylate, ditrihydroxymethylpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, dipentaerythritol hexa(meth)acrylate and the like; and polyfunctional (meth)acrylate oligomers such as urethane (meth)acrylate oligomers.

Among the compounds (a2), as the epoxy resin having an energy ray-curable group and the phenol resin having an energy ray-curable group, for example, those described in paragraph 0043 of "Japanese Patent Application Laid-Open No. 2013-194102" can be used.

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

The compound (a2) may be used alone or in combination of two or more. When two or more compounds (a2) are used, the combination and ratio thereof may be arbitrarily selected.

(Polymer (b) without energy ray curing group) When the energy ray curing resin composition (x2-1) and the energy ray curing resin film (x2) contain the compound (a2) as the energy ray curing component (a), it is preferred that they further contain: a polymer (b) without energy ray curing group. The polymer (b) without energy ray curing group may be at least partially crosslinked by a crosslinking agent or may be uncrosslinked.

Examples of the polymer (b) not having an energy ray-hardening group include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber resins, and acryl urethane resins. Among them, the polymer (b) is preferably an acrylic polymer (hereinafter, abbreviated as "acrylic polymer (b-1)").

The acrylic polymer (b-1) may be a known one, for example, a homopolymer of one acrylic monomer, or a copolymer of two or more acrylic monomers. In addition, the acrylic polymer (b-1) 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 alkyl (meth)acrylates, (meth)acrylates having a cyclic skeleton, (meth)acrylates containing a glycidyl group, (meth)acrylates containing a hydroxyl group, and (meth)acrylates containing a substituted amino group.

Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 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, Alkyl (meth)acrylates such as 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), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate) are alkyl (meth)acrylates having a chain structure with 1 to 18 carbon atoms in the alkyl group.

Examples of the (meth)acrylate having a cyclic skeleton include cycloalkyl (meth)acrylates such as isoborneol (meth)acrylate and dicyclopentyl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; cycloalkenyl (meth)acrylates such as dicyclopentenyl (meth)acrylate; and cycloalkenyloxyalkyl (meth)acrylates such as dicyclopentenyloxyethyl (meth)acrylate.

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

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

As the polymer (b) having no energy ray curable group which is at least partially crosslinked by a crosslinking agent, for example, a polymer (b) formed by reacting a reactive functional group with a crosslinking agent can be cited. The reactive functional group can be appropriately selected according to the type of the crosslinking agent, etc., and is not particularly limited. For example, when the crosslinking agent is a polyisocyanate compound, as the aforementioned reactive functional group, hydroxyl group, carboxyl group, and amino group can be cited, and among these, hydroxyl group with high reactivity with isocyanate group is preferred. Furthermore, when the crosslinking agent is an epoxy compound, as the aforementioned reactive functional group, carboxyl group, amino group, and amide group can be cited, and among these, carboxyl group with high reactivity with epoxy group is preferred. However, in order to prevent the circuit corrosion of semiconductor wafers or semiconductor chips, the above-mentioned reactive functional groups are preferably groups other than carboxyl groups.

As the polymer (b) having a reactive functional group but not having an energy ray-hardening group, for example, there can be cited a polymer obtained by polymerizing a monomer having at least a reactive functional group. In the case of an acrylic polymer (b-1), it is sufficient to use one or both of the acrylic monomer and the non-acrylic monomer cited as monomers constituting the same as the reactive functional group. For example, as the polymer (b) having a hydroxyl group as a reactive functional group, there can be cited a polymer obtained by polymerizing a hydroxyl-containing (meth)acrylate. In addition, there can be cited a monomer obtained by polymerizing a monomer in which one or two or more hydrogen atoms in the acrylic monomer or the non-acrylic monomer cited above are replaced by the reactive functional group.

In the polymer (b) having a reactive functional group, the ratio (content) of the amount of the constituent unit derived from the monomer having a reactive functional group to the total mass of the constituent unit is preferably 1-20 mass %, more preferably 2-10 mass %. When the ratio is within this range, the crosslinking degree in the polymer (b) becomes a preferred range.

From the viewpoint that the film-forming property of the energy ray-curable resin composition (x2-1) will be better, the weight average molecular weight (Mw) of the polymer (b) not having an energy ray-curable group is preferably 10,000 to 2,000,000, more preferably 100,000 to 1,500,000.

The polymer (b) not having an energy ray curable group may be used alone or in combination of two or more. When two or more polymers (b) not having an energy ray curable group are used, the combination and ratio thereof may be arbitrarily selected.

As the energy ray-curable resin composition (x2-1), there can be cited one containing either or both of the polymer (a1) and the compound (a2). Furthermore, when the energy ray-curable resin composition (x2-1) contains the compound (a2), it is also preferred to further contain a polymer (b) having no energy ray-curable group. In this case, it is also preferred to contain the polymer (a1). Furthermore, the energy ray-curable resin composition (x2-1) may not contain the compound (a2) but may contain both the polymer (a1) and the polymer (b) having no energy ray-curable group.

When the energy ray-curable resin composition (x2-1) contains a polymer (a1), a compound (a2), and a polymer (b) having no energy ray-curable group, the content of the compound (a2) is preferably 10 to 400 parts by mass, more preferably 30 to 350 parts by mass, relative to 100 parts by mass of the total content of the polymer (a1) and the polymer (b) having no energy ray-curable group.

The total content of the energy ray curable component (a) and the polymer (b) having no energy ray curable group is preferably 5 to 90 mass %, more preferably 10 to 80 mass %, and even more preferably 20 to 70 mass %, based on the total amount of the active ingredients of the energy ray curable resin composition (x2-1). When the content of the energy ray curable component is within this range, the energy ray curability of the energy ray curable resin film (x2) becomes better.

In addition to the energy ray curing component, the energy ray curing resin composition (x2-1) may also contain one or more selected from the group consisting of a thermosetting component, a photopolymerization initiator, a filler, a coupling agent, a crosslinking agent, and a general additive according to the purpose. For example, by using the energy ray curing resin composition (x2-1) containing the energy ray curing component and the thermosetting component, the formed energy ray curing resin film (x2) will improve the adhesion to the adherend by heating, and the strength of the protective film (X) formed by the energy ray curing resin film (x2) will also be improved.

The thermosetting component, photopolymerization initiator, filler, coupling agent, crosslinking agent, and general additive in the energy ray-curing resin composition (x2-1) may be the same as the thermosetting component (B), photopolymerization initiator (H), filler (D), coupling agent (E), crosslinking agent (F), and general additive (I) in the energy ray-curing resin composition (x2-1).

In the energy ray curable resin composition (x2-1), the thermosetting component, photopolymerization initiator, filler, coupling agent, crosslinking agent and general-purpose additive can be used alone or in combination of two or more. When two or more are used in combination, the combination and ratio of the thermosetting component, photopolymerization initiator, filler, coupling agent, crosslinking agent and general-purpose additive in the energy ray curable resin composition (x2-1) can be appropriately adjusted according to the purpose and is not particularly limited.

Since the energy ray-curable resin composition (x2-1) improves its operability by dilution, it is better to contain more solvent. As the solvent contained in the energy ray-curable resin composition (x2-1), for example, the same solvent as the solvent in the thermosetting resin composition (x1-1) can be cited. The solvent contained in the energy ray-curable resin composition (x2-1) can be used alone or in combination of two or more. When two or more kinds are used in combination, the combination and ratio of the solvents can be arbitrarily selected.

(Other components) In addition to the above-mentioned energy-ray-curing components, the energy-ray-curing resin composition (x2-1) may also contain appropriate amounts of components other than the curing components, such as a curing accelerator (C) or a filler (D), a coupling agent (E), etc., similar to the case of the previously described thermosetting resin film (x1).

(Production method of energy ray-hardening resin composition (x2-1)) The energy ray-hardening resin composition (x2-1) is obtained by blending the components for this purpose. The order of addition of the components when blending is not particularly limited, and two or more components may be added at the same time. When using a solvent, the solvent may be mixed with any blending component other than the solvent and the blending component may be diluted in advance before use, or the solvent may be mixed with the blending components without diluting any blending component other than the solvent in advance. There is no particular limitation on the method of mixing the ingredients during blending. You can choose from the known methods such as mixing by rotating a stirring rod or a stirring blade, mixing by using a mixer, and mixing by applying ultrasound. The temperature and time for adding and mixing the ingredients are not particularly limited as long as the blending ingredients do not deteriorate. They can be adjusted appropriately. The temperature is preferably 15~30℃.

＜＜Support sheet (Y)＞＞ The support sheet (Y) functions as a support for supporting the curable resin film (x). The support sheet (Y) may be composed of only the substrate 11 as shown in FIG. 2, may be a laminate of the substrate 11 and the adhesive layer 21 as shown in FIG. 3, or may be a laminate formed by laminating the substrate 11, the intermediate layer 31, and the adhesive layer 21 in this order as shown in FIG. 4. The laminate formed by laminating the substrate 11, the intermediate layer 31, and the adhesive layer 21 in this order is suitable for use as a back grinding tape.

The following describes the base material of the support sheet (Y), the adhesive layer and the intermediate layer that the support sheet (Y) may also have.

<Base material> The base material is in the form of a sheet or a film, and as its constituent material, for example, the following various resins can be cited. As the resin constituting the base material, for example, polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylate copolymers, ethylene-norbornene copolymers, and other ethylene-based copolymers (copolymers obtained using ethylene as a monomer); polyvinyl chloride, vinyl chloride copolymers, and other vinyl chloride copolymers. Olefin resin (resin obtained by using vinyl chloride as a monomer); polystyrene; polycycloolefin; polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalene dicarboxylate, polyesters such as fully aromatic polyesters having aromatic cyclic groups as all constituent units; copolymers of two or more of the aforementioned polyesters; poly(meth)acrylate; polyurethane; polyurethane acrylate; polyimide; polyamide; polycarbonate; fluororesin; polyacetal; modified polyphenylene ether; polyphenylene sulfide; polysulfone; polyether ketone, etc. In addition, as the resin constituting the substrate, for example, a polymer alloy such as a mixture of the aforementioned polyester and a resin other than the aforementioned polyester can also be cited. The polymer alloy of the aforementioned polyester and other resins is preferably one in which the amount of the resin other than the polyester is relatively small. In addition, as the resin constituting the substrate, for example, one or more of the above-mentioned resins exemplified so far are cross-linked cross-linked resins; and modified resins using one or more of the above-mentioned resins exemplified so far are ionic polymers.

The resin constituting the substrate may be used alone or in combination of two or more. When there are two or more resins constituting the substrate, the combination and ratio thereof may be arbitrarily selected.

The substrate may be a single layer or a plurality of layers including two or more layers. When the substrate is a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited.

The thickness of the substrate is preferably 5μm~1,000μm, more preferably 10μm~500μm, more preferably 15μm~300μm, and more preferably 20μm~150μm. Here, "the thickness of the substrate" means the thickness of the entire substrate. For example, the thickness of a substrate composed of multiple layers refers to the total thickness of all layers constituting the substrate.

The substrate is preferably one with high thickness accuracy, that is, one with no thickness difference depending on the location and with suppressed thickness deviation. Among the above-mentioned constituent materials, materials with high thickness accuracy that can be used as such a constituent substrate include, for example, polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, ethylene-vinyl acetate copolymer, and the like.

In addition to the main constituent materials such as the aforementioned resin, the substrate may also contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, softeners (plasticizers), etc.

The substrate may be transparent or opaque, and may be colored according to the purpose, or may be deposited with other layers. In addition, when the curable resin film (x) is an energy ray curable resin film (x2), and when the adhesive layer is an energy curable adhesive layer, the substrate is preferably one that allows energy rays to penetrate.

The substrate can be manufactured by a known method. For example, a substrate containing a resin can be manufactured by molding a resin composition containing the above-mentioned resin.

<Adhesive layer> The adhesive layer is in the form of a sheet or a film and contains an adhesive. Examples of adhesives include acrylic resins (adhesives composed of resins having a (meth)acrylic group), urethane resins (adhesives composed of resins having a urethane bond), rubber resins (adhesives composed of resins having a rubber structure), silicone resins (adhesives composed of resins having a siloxane bond), epoxy resins (adhesives composed of resins having an epoxy group), polyvinyl ether, polycarbonate, and other adhesive resins. Among these, acrylic resin is preferred.

Furthermore, in the present invention, "adhesive resin" refers to a concept including both resins having adhesive properties and resins having bonding properties. For example, it includes not only resins having adhesive properties themselves, but also resins that exhibit adhesive properties by using other components such as additives, or resins that exhibit bonding properties by the presence of a trigger such as heat or water.

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

The thickness of the adhesive layer is preferably 1 μm to 1,000 μm, more preferably 5 μm to 500 μm, and even more preferably 10 μm to 100 μm. Here, "the thickness of the adhesive layer" refers to the thickness of the entire adhesive layer. For example, the thickness of an adhesive layer composed of multiple layers refers to the total thickness of all layers constituting the adhesive layer.

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

<Intermediate layer> The intermediate layer is in the form of a sheet or a film, and its constituent material can be appropriately selected according to the purpose, and is not particularly limited. For example, when the purpose is to suppress the deformation of the protective film (X) covering the semiconductor surface due to the reflection of the shape of the bumps on the semiconductor surface, as a better constituent material for the intermediate layer, from the perspective of improving the uneven tracking performance, the perspective of making the bump penetration good, and the perspective of further improving the adhesion of the intermediate layer, urethane (meth) acrylate can be cited.

The intermediate layer may be a single layer or a plurality of layers of two or more. When the intermediate layer is a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited.

The thickness of the interlayer can be adjusted appropriately according to the height of the bumps on the semiconductor surface to be protected. On the surface that can easily absorb the impact of the bumps with high relative height, 50μm~600μm is preferred, 70μm~500μm is more preferred, and 80μm~400μm is more preferred. Here, "the thickness of the interlayer" refers to the thickness of the entire interlayer. For example, the thickness of the interlayer composed of multiple layers refers to the total thickness of all layers constituting the interlayer.

Next, a method for producing a protective film-forming sheet will be described.

[Manufacturing method of protective film forming sheet] The protective film forming sheet can be manufactured by laminating in order in a manner corresponding to the positional relationship of each layer described above. For example, when laminating an adhesive layer or an intermediate layer on a substrate during the manufacture of a support sheet, an adhesive composition or an intermediate layer forming composition can be applied to the substrate and dried as necessary, or the adhesive layer or the intermediate layer can be laminated by irradiating energy rays. As coating methods, for example, rotary coating, spray coating, rod coating, knife coating, roller coating, knife-roll coating, scraper coating, die coating, gravure coating, etc. can be cited.

On the other hand, for example, when a curable resin film (x) is laminated on an adhesive layer laminated on a substrate, a thermosetting resin composition (x1-1) or an energy ray curable resin composition (x2-1) can be applied on the adhesive layer to directly form the curable resin film (x). Similarly, when an adhesive layer is laminated on an intermediate layer laminated on a substrate, an adhesive composition can be applied on the intermediate layer to directly form the adhesive layer.

In this way, when forming a laminated structure of two consecutive layers using any composition, a new layer can be formed by coating a composition on the layer formed by the aforementioned composition. However, of the two layers, the layer to be laminated later is preferably formed by using the aforementioned composition on another release film in advance, and the exposed surface of the formed layer opposite to the side in contact with the aforementioned release film is bonded to the exposed surface of the remaining layer that has been formed, thereby forming a laminated structure of two consecutive layers. At this time, the aforementioned composition is preferably coated on the release-treated surface of the release film. The release film can be removed as necessary after the formation of the laminated structure.

[Method for manufacturing a semiconductor wafer with a protective film using a protective film forming sheet] The method for manufacturing a semiconductor wafer with a protective film of the present invention is implemented using the protective film forming sheet of the present invention. Specifically, it includes the following steps (S1) to (S3). ・Step (S1): preparing a semiconductor wafer having a bump forming surface on which a plurality of bumps are provided ・Step (S2): pressing the curable resin film (x) of the protective film forming sheet of the present invention as an attachment surface onto the aforementioned bump forming surface of the aforementioned semiconductor wafer and attaching the same; ・Step (S3): curing the curable resin film (x) to form a protective film (X) Below, the semiconductor wafer as an applicable object and the method for manufacturing the semiconductor wafer with a protective film of the present invention are described in detail.

<Step (S1)> Step (S1) is a step of preparing a semiconductor wafer having a bump forming surface on which a plurality of bumps are provided An example of a semiconductor wafer having a bump forming surface on which a plurality of bumps are provided, which is used in the method for manufacturing a semiconductor wafer with a protective film of the present invention, is shown in FIG5. The semiconductor wafer 40 having bumps has a plurality of bumps BM on the bump forming surface (electrical surface) 41a of the semiconductor wafer 41. In the following description, the "semiconductor wafer having bumps" is also referred to as a "wafer with bumps". The "semiconductor wafer" is also simply referred to as a "wafer".

The wafer 41 has circuits such as wiring, capacitors, diodes, and transistors formed on its surface. The material of the wafer is not particularly limited, and examples thereof include silicon wafers, silicon carbide wafers, compound semiconductor wafers, sapphire wafers, and glass wafers.

The size of the wafer 41 is not particularly limited. From the perspective of improving batch processing efficiency, it is usually 8 inches (200 mm in diameter) or larger, preferably 12 inches (300 mm in diameter) or larger. Moreover, the shape of the wafer is not limited to a circle, and may be a square or rectangular shape, for example. In the case of an angular wafer, from the perspective of improving batch processing efficiency, the length of the longest side of the wafer 41 is preferably larger than the above-mentioned size (diameter).

The thickness of the wafer 41 is not particularly limited, but is preferably 100 μm to 1,000 μm, more preferably 200 μm to 900 μm, and even more preferably 300 μm to 800 μm from the viewpoint of easily suppressing the warping of the wafer 41 accompanying the curing of the curable resin film (x).

The shape of the bump BM is not particularly limited. It can be any shape as long as it can contact and fix with the electrode on the substrate for chip mounting. For example, although the bump BM is made into a spherical shape in FIG5, the bump BM can also be a rotation ellipse. The rotation ellipse can be, for example, a rotation ellipse extending in the vertical direction of the bump forming surface 41a of the wafer 41, or a rotation ellipse extending in the horizontal direction of the bump forming surface 41a of the wafer 41. In addition, the bump BM can also be a pillar shape as shown in FIG6. Moreover, as the material of the bump BM, for example, solder can be cited.

Here, the object of application of the present invention is a semiconductor wafer having bumps with narrow pitches as specified by the requirements described below. That is, in the present invention, by using a protective film forming sheet, a protective film (X) is formed on the bump forming surface of a semiconductor wafer having bumps with narrow pitches, so that the collapse or deformation of the bumps with narrow pitches can be suppressed and short circuits between the bumps can be prevented. In other words, the semiconductor wafer to which the present invention is applied is a semiconductor wafer having bumps with narrow pitches, which has concerns about short circuits caused by collapse or deformation of the bumps when the protective film (X) is not formed. The semiconductor wafer described below is a semiconductor wafer with narrow-pitch bumps, which may cause short circuits due to collapse or deformation of the bumps, if a protective film (X) is not formed.

＜＜Semiconductor wafer＞＞ The protective film forming sheet of the present invention is used to form a protective film (X) on the bump forming surface of a semiconductor wafer that satisfies the following requirements (α1) to (α2). Furthermore, the manufacturing method of a semiconductor wafer with a protective film of the present invention is implemented using a semiconductor wafer that satisfies the following requirements (α1) to (α2). ・Requirement (α1): The width ( _BMw ) (unit: μm) of the aforementioned bump is 20μm to 350μm. ・Requirement (α2): The pitch ( _BMp ) (unit: μm) of the aforementioned bump and the width ( _BMw ) (unit: μm) of the aforementioned bump satisfy the following formula (I).

The above-mentioned requirements (α1) to (α2) are indicators of a semiconductor wafer having bumps with narrow pitches. That is, they are indicators that a short circuit caused by collapse or deformation of the bumps is likely to occur. In order to illustrate the definition of the bump pitch ( _BMP ) (unit: μm) and the bump width ( _BMw ) (unit: μm), FIG. 7 shows an enlarged top view of three bumps BM_a, BM_b, and BM_c formed on the bump forming surface of the wafer 41. The bump pitch ( _BMP ) is the shortest distance between bumps at two points. In FIG. 7, the shortest distance between bump BM_a and bump BM_b is _P1 . Furthermore, the shortest distance between the bump BM_b and the bump BM_c is _P2 . The width of the bump ( _BMw ) is the length of _{the straight line b1-b2 connecting the} contact _b1 and the contact b2, wherein the contact _b1 is the contact point of the straight line _P1 connecting the bump BM_a and the bump BM_b with the bump BM_b, and the contact _b2 is the contact point of the straight line _P2 connecting the bump BM_b and the bump BM_c with the bump BM_b. Moreover, the bump pitch ( _BMp ) (unit: μm) and the bump width ( _BMw ) (unit: μm) are based on the above definition, and can be measured, for example, by observation under an optical microscope.

Furthermore, when the above requirements (α1) to (α2) are satisfied between at least one of the plurality of bumps on the wafer, there is a concern that short circuits may occur between the bumps because the pitch between the bumps is narrow. Therefore, the wafer to which the present invention is applicable is a wafer that satisfies the above requirements (α1) to (α2) between at least one of the plurality of bumps on the wafer.

Here, requirement (α1) stipulates that the width ( _BMw ) of the bump (unit: μm) is 20μm~350μm. That is, according to the present invention, a wafer having a plurality of bumps with a small width ( _BMw ) of 20μm or more and less than 150μm (especially 20μm~100μm) can also be used as an object. In other words, a wafer having a plurality of narrow pitch and tiny bumps can also be used as an object. In addition, a wafer having a plurality of bumps with a large width ( _BMw ) of 150μm~350μm can also be used as an object. In other words, a wafer having a plurality of narrow pitch and large width bumps can also be used as an object. A wafer having a plurality of narrow pitch and large width bumps is particularly prone to short circuits between the bumps. The present invention can suppress short circuits between the bumps of such a wafer.

Here, the value of [(BM _P )/(BM _w )] specified in the requirement (α2) is one of the indicators of the susceptibility of short circuits between bumps, and the value may be 0.9 or less, or 0.8 or less.

Here, the wafer may further satisfy the following requirement (α3a) or the following requirement (α3b). Requirement (α3a): The height (BM _h ) of the bump and the width (BM _w ) of the bump satisfy the following formula (IIIa):・Requirement (α3b): The height (BM _h ) of the bump and the width (BM _w ) of the bump satisfy the following formula (IIIb):

The above-mentioned requirement (α3a) is an indicator showing that the bump is a spherical bump. The closer the value of [(BM _h )/(BM _w )] is to 1.0, the closer it is to a true sphere. The closer it is to 0.2, the wafer 41 is a rotational ellipse extending in the horizontal direction with respect to the bump forming surface 41a. When a semiconductor wafer having such a spherical bump is singulated to form a semiconductor chip, and the semiconductor chip is electrically connected to a wiring substrate via the spherical bump, the spherical bump may collapse and expand laterally, and the spherical bumps may contact each other and cause a short circuit. In order to meet the requirements of higher density packaging, three-dimensional high-density packaging in which semiconductor packages are stacked in the height direction is also considered. In this case, the ball bumps may gradually collapse due to the weight of the semiconductor package itself, thereby causing a short circuit. The present invention can suppress the short circuit caused by the contact between the ball bumps.

The above requirement (α3b) is an indicator of whether the bump is a columnar bump. The closer the value of [(BM _h )/(BM _w )] is to 5.0, the higher the aspect ratio of the columnar bump. The closer it is to 0.5, the lower the aspect ratio of the columnar bump. When a semiconductor wafer having such a columnar bump is singulated to form a semiconductor chip, the columnar bump may be deformed and bent during the step of electrically connecting the semiconductor chip to a wiring board via the columnar bump, and the columnar bumps may contact each other and cause a short circuit. In addition, the columnar bump may be deformed and bent, which may cause a poor connection. In order to meet the requirements of higher density packaging, three-dimensional high-density packaging in which semiconductor packages are stacked in the height direction is also considered. In this case, the columnar bumps may gradually deform due to the weight of the semiconductor package itself, thereby causing short circuits. The present invention can suppress short circuits caused by contact between columnar bumps. In addition, it can also suppress poor connections caused by deformation of columnar bumps.

Furthermore, the bump height (BM _h ) means the distance of a straight line connecting the contact point of the bump forming surface with the bump and the part of the bump located farthest from the bump forming surface when focusing on one bump. Specifically, the bump height (BM _h ) may be a value specified by the following requirement (α4). Requirement (α4): The aforementioned bump height (BM _h ) is 15 μm to 300 μm. That is, one aspect of the present invention is that a wafer having a plurality of bumps having a bump height (BM _h ) of 20 μm or more and less than 150 μm (particularly 20 μm to 100 μm) may be used as an object. Alternatively, a wafer having a plurality of bumps with a height (BM _h ) of 150 μm to 350 μm may be used as an object. The height (BM _h ) of the bump may be measured, for example, by observing a cross section through an optical microscope, the cross section being a cross section obtained by cutting the semiconductor wafer with the bumps in a direction perpendicular to the bump formation surface and passing through the center of the bump.

<Step (S2)> The outline of step (S2) is shown in FIG8. In step (S2), the curable resin film (x) of the protective film forming sheet 1 of the present invention is pressed against the bump forming surface 41a of the semiconductor wafer 41 as an attachment surface and attached. In this way, the bump forming surface 41a of the semiconductor wafer 41 is covered with the curable resin film (x), and the curable resin film (x) is also filled between the plurality of bumps BM.

Furthermore, from the perspective of better filling the curable resin film (x) between the plurality of bumps BM, the pressing force when attaching the protective film forming sheet 1 to the bump forming surface 41a of the semiconductor wafer 41 is preferably 1kPa~200kPa, preferably 5kPa~150kPa, and more preferably 10kPa~100kPa. Furthermore, the pressing force when attaching the protective film forming sheet 1 to the bump forming surface 41a of the semiconductor wafer 41 can also be appropriately changed from the initial attachment to the final stage. For example, from the perspective of better filling the curable resin film (x) between the plurality of bumps BM, it is better to lower the pressing force at the initial attachment and then gradually increase the pressing force.

When the protective film forming sheet 1 is attached to the bump forming surface 41a of the semiconductor wafer 41, if the curable resin film (x) is a thermosetting resin film (x1), it is preferable to heat it from the viewpoint of better filling the curable resin film (x) between the plurality of bumps BM. If the curable resin film (x) is a thermosetting resin film (x1), the fluidity of the thermosetting resin film (x1) is temporarily improved by heating, and the curing is performed by continuing heating. Therefore, by heating the thermosetting resin film (x1) within a range where the fluidity of the thermosetting resin film (x1) is improved, the thermosetting resin film (x1) becomes easy to move between the plurality of bumps BM, thereby further improving the filling property of the thermosetting resin film (x1) between the plurality of bumps BM. As a specific heating temperature (sticking temperature), 50°C to 150°C is preferred, 60°C to 130°C is preferred, and 70°C to 110°C is more preferred. Moreover, the heat treatment of the thermosetting resin film (x1) is not included in the curing treatment of the thermosetting resin film (x1).

Furthermore, when the protective film forming sheet 1 is attached to the bump forming surface 41a of the semiconductor wafer 41, it can also be made to be carried out in a reduced pressure environment. Thereby, a negative pressure is formed between the multiple bumps BM, and the curable resin film (x) becomes easy to move between the multiple bumps BM. As a result, the filling property of the curable resin film (x) between the multiple bumps BM becomes easier and more improved. As a specific pressure of the reduced pressure environment, 0.001kPa~50kPa is preferred, 0.01kPa~5kPa is more preferred, and 0.05kPa~1kPa is more preferred.

<Step (S3)> After performing step (S2), perform step (S3). Specifically, as shown in FIG9, a semiconductor wafer with a protective film is obtained by forming a curable resin film (x). The protective film (X) formed by curing the curable resin film (x) becomes stronger than the curable resin film (x) at room temperature (23°C). Therefore, by forming the protective film (X), the bump neck is well protected. In addition, since the present invention uses a protective film forming sheet that satisfies the above requirements (β1) to (β3), as described above, for a semiconductor wafer with narrowed-pitch bumps that has concerns about short circuits caused by bump collapse or deformation, the bump collapse or deformation can be suppressed, and short circuits caused by contact between bumps can be avoided.

The curing of the curable resin film (x) can be performed by either thermal curing or curing by irradiation of energy rays, depending on the type of curable component contained in the curable resin film (x). As a condition for thermal curing, the curing temperature is preferably 90°C to 200°C, and the curing time is preferably 1 hour to 3 hours. As a condition for curing by irradiation of energy rays, it can be appropriately set according to the type of energy rays used. For example, when ultraviolet rays are used, the illumination is preferably 170mw/ ^cm2 to 250mw/ ^cm2 , and the light intensity is preferably 300mJ/ ^cm2 to 3000mJ/ ^cm2 .

Here, in the process of hardening the hardening resin film (x) to form the protective film (X), from the viewpoint of removing bubbles that may be mixed in when the hardening resin film (x) is used to fill the gaps between the plurality of bumps BM in step (S2), the hardening resin film (x) is preferably a thermosetting resin film (x1). That is, when the hardening resin film (x) is a thermosetting resin film (x1), the fluidity of the thermosetting resin film (x1) is temporarily improved due to heating, and the hardening is performed by continuing to heat. By utilizing this phenomenon, when the fluidity of the thermosetting resin film (x1) is improved, bubbles that may be mixed in when the thermosetting resin film (x1) is used to fill the space between the plurality of bumps BM are removed, thereby making it possible to make the thermosetting resin film (x1) fill the space between the plurality of bumps BM better, and harden the thermosetting resin film (x1). In addition, from the perspective of shortening the curing time, the curable resin film (x) is preferably an energy ray curable resin film (x2).

Furthermore, the support sheet (Y) is peeled off before the curable resin film (x) is cured, and the protective film (X) is formed by curing the curable resin film (x), thereby obtaining a semiconductor wafer with a protective film. However, the present invention is not limited to this embodiment, and a semiconductor wafer with a protective film can be obtained by peeling off the support sheet (Y) after the curable resin film (x) is cured to form a protective film (X). In addition, the semiconductor wafer 41 can be thinned by grinding (back grinding) the surface opposite to the bump forming surface 41a of the semiconductor wafer 41 (i.e., the back of the semiconductor wafer 41) without peeling off the support sheet (Y). The back grinding process can be performed before or after the curing of the curable resin film (x). In addition, when performing the back grinding process, from the perspective of performing the back grinding process well, the support sheet (Y) is preferably a back grinding tape.

In addition, after the curing of the curable resin film (x), the protective film (X) covering the top of the bump or the protective film (X) attached to a portion of the top of the bump can be removed to expose the top of the bump. As an exposure treatment for exposing the top of the bump, an etching treatment such as a wet etching treatment or a dry etching treatment can be cited. Here, as a dry etching treatment, a plasma etching treatment can be cited. Moreover, in the case where the top of the bump is not exposed on the surface of the protective film, the exposure treatment can be performed for the purpose of allowing the protective film to retreat and expose the top of the bump.

[Method for manufacturing a semiconductor wafer with a protective film] The method for manufacturing a semiconductor wafer with a protective film of the present invention comprises the following steps (T1) to (T2). ・Step (T1): A step of obtaining a semiconductor wafer with a protective film by implementing the method for manufacturing a semiconductor wafer with a protective film of the present invention ・Step (T2): A step of singulating the aforementioned semiconductor wafer with a protective film

<Step (T1)> Step (T1) is to implement the above-mentioned method for manufacturing a semiconductor wafer with a protective film of the present invention to obtain a semiconductor wafer with a protective film.

<Step (T2)> Step (T2) is to singulate the semiconductor wafer with the protective film obtained in step (T1). The singulation method is not particularly limited, and a known singulation method can be appropriately adopted. Specifically, for example, laser dicing, knife dicing, and stealth dicing (registered trademark) can be cited.

Furthermore, before performing step (T1), a step of forming a back side protective film on the back side (the side opposite to the bump forming side) of the semiconductor wafer with the protective film may be included.

[Manufacturing method of semiconductor package] The manufacturing method of the semiconductor package of the present invention includes the following steps (U1)~(U2). ・Step (U1): A step of obtaining a semiconductor chip with a protective film by implementing the manufacturing method of the semiconductor chip with a protective film of the present invention ・Step (U2): A step of electrically connecting the wiring substrate and the semiconductor chip with a protective film through the aforementioned bump

<Step (U1)> Step (U1) is to implement the manufacturing method of the semiconductor chip with a protective film of the present invention to obtain the semiconductor chip with a protective film.

<Step (U2)> Step (U2) is to electrically connect the wiring substrate (Z) having the wiring Z1 and the semiconductor chip CP with a protective film through the bump BM as shown in FIG. 10. More specifically, heating is performed in a state where the bump forming surface of the semiconductor chip CP with a protective film and the wiring Z1 forming surface of the wiring substrate (Z) are opposite to each other through the bump BM (hereinafter also referred to as "heating connection step"). In this way, the top of the bump BM and the wiring Z1 can be electrically connected well. Furthermore, in the present invention, although a semiconductor chip obtained from a semiconductor wafer having narrowed pitch bumps which has concerns about short circuits caused by bump collapse or deformation is used, the protective film forming sheet of the present invention can suppress contact between bumps caused by bump collapse or deformation in the heat connection step, and can avoid short circuits caused by contact between bumps by satisfying the above requirements (β1) to (β3), especially by satisfying the above requirement (β2). The conditions of the heat connection step are, for example, 30 seconds to 5 minutes at a temperature of 250°C to 270°C.

<Step (U3)> The method for manufacturing a semiconductor package according to one aspect of the present invention further includes the following step (U3). ・Step (U3): A step of filling a bottom filling material between the aforementioned wiring substrate and the aforementioned semiconductor chip with a protective film The present invention, as described above, can suppress the contact between bumps caused by the collapse or deformation of the bumps. In other words, it can suppress the approach of bumps caused by the collapse or deformation of the bumps. In the past, if the bumps were brought close to each other, even if an attempt was made to fill the bottom filling material, it was difficult to fill the gap with the bottom filling material because the gap between the bumps was narrow. However, in the present invention, since the approach of the bumps is also suppressed, the gaps between the protective film (X) and the wiring substrate (Z), including the gaps between the bumps, can also be well filled with the bottom filling material. [Example]

The present invention is specifically described by the following embodiments, but the present invention is not limited to the following embodiments.

[Measurement methods of various physical properties] The physical properties of the following examples and comparative examples are measured using the following methods.

<Weight average molecular weight> Measured using a gel permeation chromatograph (manufactured by Tosoh Corporation, product name "HLC-8020") under the following conditions, using the value measured after standard polystyrene conversion. (Measurement conditions) ・Column: "TSK guard column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL", "TSK gel G1000HXL" (all manufactured by Tosoh Corporation) connected in order ・Column temperature: 40°C ・Developing solvent: tetrahydrofuran ・Flow rate: 1.0mL/min

<Measurement of thickness of each layer> Thicknesses other than the thickness of the protective film (after curing) (X _T ) were measured using a constant pressure thickness gauge manufactured by Teclock Co., Ltd. (model: "PG-02J", standard specification: in accordance with JIS K6783, Z1702, Z1709).

<Glass transition temperature> The glass transition temperature (Tg) of the polymer component (A) described below was measured using a differential scanning calorimeter (PYRIS Diamond DSC) manufactured by Perkin Elmer Co., Ltd., at a temperature distribution of -70°C to 150°C at a heating and cooling rate of 10°C/min, and the inflection point was confirmed and obtained.

<Epoxy equivalent> Measured in accordance with JIS K 7236:2009.

<Average Particle Size> The particles to be measured were dispersed in water by ultrasound, and the particle size distribution was measured on a volume basis using a dynamic light scattering particle size distribution measurement device (manufactured by Horiba, Ltd., LB-550). The particle size distribution was measured, and the average particle size (D ₅₀ ) was taken as the average particle size.

[Example 1-4, Comparative Example 1-2] The thermosetting resin composition (x1-1) used to manufacture the thermosetting resin film (x1) used in the example is prepared by the following method.

<Raw materials for the thermosetting resin composition (x1-1)> (Polymer component (A)) Polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., Eslec (registered trademark) B BL-10, weight average molecular weight 25,000, glass transition temperature 59°C) having constituent units represented by the following formula (i-1), the following formula (i-2), and the following formula (i-3) is used. In the following formula, p is 68~74 mol%, q is 1~3 mol%, and r is about 28 mol%).

(Epoxy resin (B1)) The following two epoxy resins were used. ・Epoxy resin (B1-1): Liquid bisphenol A type epoxy resin (manufactured by DIC Corporation, EPICLON (registered trademark) EXA-4850-1000, epoxy equivalent 404~412g/eq) ・Epoxy resin (B1-2): Dicyclopentadiene type epoxy resin (manufactured by DIC Corporation, EPICLON (registered trademark) HP-7200, epoxy equivalent 254~264g/eq)

(Thermosetting agent (B2)) Novolac type phenolic resin (Showa Denko Co., Ltd., Shonol (registered trademark) BRG-556) was used.

(Curing accelerator (C)) 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemical Industries, Ltd., Curezol (registered trademark) 2PHZ) was used.

(Filling material (D)) Epoxy-modified spherical silica (Admanano (registered trademark) YA050C-MKK, manufactured by Admatex Co., Ltd., average particle size 0.05 μm) was used.

<Preparation of thermosetting resin composition (x1-1)> The polymer component (A), epoxy resin (B1-1), epoxy resin (B1-2), thermosetting agent (B2), curing accelerator (C), and filler (D) are dissolved or dispersed in methyl ethyl ketone in such a manner that the total amount (100% by mass) of the thermosetting resin composition (x1-1) becomes the content shown below, and stirred at 23°C to prepare a thermosetting resin composition (x1-1) having an active ingredient (solid component) concentration of 55% by mass. In Examples 1 and 2, the protective film (X) is formed using the thermosetting resin composition (x1-1) prepared by the blend 1 shown below. In addition, in Examples 3 and 4, the thermosetting resin composition (x1-1) prepared by the blend 2 shown below is used to form a protective film (X). (Blending 1) ・Polymer component (A): 41.4 mass% ・Epoxy resin (B1-1): 23.2 mass% ・Epoxy resin (B1-2): 15.2 mass% ・Thermosetting agent (B2): 11.2 mass% ・Curing accelerator (C): 0.2 mass% ・Filler (D): 8.8 mass% (Blending 2) ・Polymer component (A): 19.9 mass% ・Epoxy resin (B1-1): 33.1 mass% ・Epoxy resin (B1-2): 21.7 mass% ・Thermosetting agent (B2): 16.1 mass% ・Curing accelerator (C): 0.2 mass% ・Filling material (D): 9.0 mass%

<Production of thermosetting resin film (x1)> A release material made of polyethylene terephthalate (SP-PET381031 manufactured by Lintec Co., Ltd., thickness 38 μm) having a release surface treated with silicone was coated with the thermosetting resin composition (x1-1) prepared by blending 1, and dried at 120°C for 2 minutes to obtain a thermosetting resin film (x1: blending 1) with a thickness of 30 μm. In addition, a thermosetting resin film (x1: blending 2) with a thickness of 50 μm was obtained by the same method except that the thermosetting resin composition (x1-1) prepared by blending 2 was used.

<Manufacturing of protective film forming sheet> A laminating tape (E-8510HR manufactured by Lintec Co., Ltd.) in which a base material (thickness: 100 μm), an intermediate layer (thickness: 400 μm), and an adhesive layer (thickness: 10 μm) are laminated in this order is used as a supporting sheet (Y), and the adhesive layer of the laminating tape is laminated to a 30 μm thick thermosetting resin film (x1: blend 1) formed on a release material, thereby manufacturing a protective film forming sheet 1 in which a supporting sheet (Y), a thermosetting resin film (x1), and a release material are laminated in this order. Regarding the thermosetting resin film (x1: blending 2) with a thickness of 50μm, the protective film forming sheet 2 is also manufactured by the same operation sequence.

[Measurement of tensile modulus E' of protective film (X)] After curing the thermosetting resin film (x1), the tensile modulus E' of the protective film (X) was measured by the following method. First, 6 thermosetting resin films (x1: blend 1) with a thickness of 30 μm were stacked to produce a sample with a thickness of 0.18 mm, a width of 4.5 mm, and a length of 20.0 mm. The sample was heat-treated in a pressure oven (RAD-9100 manufactured by Lintec Co., Ltd.) at a temperature of 130°C, a time of 2 h, and an internal pressure of 0.5 MPa to obtain a protective film (X). Next, the protective film (X) was subjected to the tensile mode using a dynamic viscoelasticity measuring device (manufactured by TA Instruments, product name "DMA Q800"), and the tensile modulus E' (23°C) of the protective film (X) was measured at a frequency of 11 Hz, 23°C, and in an atmospheric environment. In addition, the tensile modulus E' (260°C) of the protective film (X) was measured under the same conditions except that the temperature during the measurement was set to 260°C. Regarding the thermosetting resin film (x1: blend 2), except for stacking 4 thermosetting resin films (x1: blend 2) with a thickness of 50μm and making it 0.20mm thick, the same operation sequence was used to obtain the protective film (X), and the tensile modulus of elasticity E' (23℃) and the tensile modulus of elasticity E' (260℃) of the protective film (X) were measured.

[Short circuit evaluation] The peeling material is removed from the protective film forming sheet obtained above, and the surface (exposed surface) of the thermosetting resin layer exposed thereby is pressed against the bump forming surface of the wafer with ball bumps, and the protective film forming sheet is attached to the bump forming surface of the semiconductor wafer. At this time, the attachment of the protective film forming sheet is performed using an attachment device (roller laminator, "RAD-3510 F/12" manufactured by Lintec Co., Ltd.) under the conditions of a workbench temperature of 90°C, an attachment speed of 2mm/sec, and an attachment pressure of 0.5MPa, while heating the thermosetting resin film (x1) and performing the attachment simultaneously. The details of the wafer with ball bumps to which the protective film forming sheets 1 and 2 were attached (elements (α1), (α2), (α3a), and (α4)) are shown in Table 1. Then, the support sheet (Y) of the protective film forming sheet was peeled off by ultraviolet irradiation using RAD-2700 manufactured by Lintec Co., Ltd. The wafer with bumps to which the thermosetting resin film (x1) was attached was heat-treated in a pressure oven (RAD-9100 manufactured by Lintec Co., Ltd.) under heating conditions of temperature: 130°C, time: 2h, and furnace internal pressure: 0.5MPa to thermally cure the thermosetting resin film (x1) to obtain a semiconductor wafer with a protective film (X) (Examples 1 to 4). The thickness ( _XT ) of the protective film (X) is measured by cutting the semiconductor wafer with the protective film (X) in a direction perpendicular to the bump formation surface and passing through the center of the bump, and observing the cut cross section with an optical microscope. In addition, the bump formation surface of the semiconductor wafer with the protective film (X) and the wiring formation surface of the wiring substrate are placed opposite to each other with the bumps interposed therebetween, and heat treatment is performed at 260°C for 1 minute (heat connection step) to evaluate the presence or absence of contact between the bumps (presence or absence of short circuit). Furthermore, as a comparative test, the same wafers with bumps as in Examples 1 and 3 and Examples 2 and 4 but without the protective film (X) were subjected to the heat connection step and evaluated for the presence of short circuits (Comparative Examples 1 and 2). The results are shown in Table 1.

The following can be learned from Table 1. It is known that Examples 1 to 4 can suppress bump short circuits regardless of whether or not a semiconductor wafer with bumps having narrow pitches is used. On the other hand, as shown in Comparative Examples 1 and 2, it is known that in the case where a protective film (X) is not provided, bump short circuits of a semiconductor wafer with bumps having narrow pitches cannot be suppressed.

1,1a,1b,1c: Sheet for forming protective film x: Curable resin film x1: Thermosetting resin film x2: Energy ray curing resin film X: Protective film Y: Support sheet 11: Substrate 21: Adhesive layer 31: Intermediate layer 40: Semiconductor wafer with bumps 41: Semiconductor wafer 41a: Bump forming surface BM: Bump CP: Semiconductor chip with protective film Z: Wiring board Z1: Wiring

[Figure 1] A schematic cross-sectional view showing the structure of a protective film forming sheet of the present invention. [Figure 2] A schematic cross-sectional view showing an example of the structure of a protective film forming sheet of one embodiment of the present invention. [Figure 3] A schematic cross-sectional view showing another example of the structure of a protective film forming sheet of one embodiment of the present invention. [Figure 4] A schematic cross-sectional view showing another example of the structure of a protective film forming sheet of one embodiment of the present invention. [Figure 5] A schematic cross-sectional view showing an example of a semiconductor wafer having a plurality of bumps. [Figure 6] A schematic cross-sectional view showing another example of a semiconductor wafer having a plurality of bumps. [Figure 7] A top view of three bumps on a semiconductor wafer enlarged to define the bump pitch (BM _P ) and the bump width (BM _w ). [Fig. 8] A schematic cross-sectional view illustrating step (S2) of a method for manufacturing a semiconductor wafer with a protective film according to one embodiment of the present invention. [Fig. 9] A schematic cross-sectional view illustrating step (S3) of a method for manufacturing a semiconductor wafer with a protective film according to one embodiment of the present invention. [Fig. 10] A schematic cross-sectional view illustrating step (U2) of a method for manufacturing a semiconductor package according to one embodiment of the present invention. [Fig. 11] A schematic cross-sectional view showing the relationship between the height ( _BMh ) of a bump and the thickness ( _XT ) (unit: μm) of a protective film (X) formed by curing a curable resin film (x) at 23°C.

1: Sheet for forming protective film x: Curable resin film Y: Support sheet

Claims (10)

A protective film forming sheet having a laminated structure of a curable resin film (x) and a supporting sheet (Y), wherein the curable resin film (x) is a thermosetting resin film (x1), and the thermosetting resin film (x1) contains a polymer component (A) including polyvinyl acetal and a thermosetting component including an epoxy resin (B1); the protective film forming sheet is used to form a protective film (X) on a bump forming surface of a semiconductor wafer having a plurality of bumps and satisfying the following requirements (α1) to (α2), and the protective film forming sheet satisfies the following requirements (β1) to (β3); Requirement (α1): the width ( _BMw ) (unit: μm) of the bump is 20 μm to 350 μm;・Requirement (α2): The bump pitch (BM _P ) (unit: μm) and the bump width (BM _w ) (unit: μm) satisfy the following formula (I):・Requirement (β1): The tensile modulus E'(23°C) of the protective film (X) formed by curing the curable resin film (x) at 23°C is 1×10 ⁷ Pa to 1×10 ¹⁰ Pa. ・Requirement (β2): The tensile modulus E'(260°C) of the protective film (X) formed by curing the curable resin film (x) at 260°C is 1×10 ⁵ Pa to 1×10 ⁸ Pa. ・Requirement (β3): The thickness (XT) (unit: μm) of the protective film (X) formed by curing the curable resin film ( _x ) at 23°C and the height ( _BMh ) (unit: μm) of the bump satisfy the following formula (II): A protective film forming sheet having a laminated structure of a curable resin film (x) and a supporting sheet (Y), the protective film forming sheet being used to form a protective film (X) on a bump forming surface of a semiconductor wafer having a plurality of bumps and satisfying the following requirements (α1) to (α2), and the protective film forming sheet satisfying the following requirements (β1) to (β3); Requirement (α1): the width ( _BMw ) (unit: μm) of the aforementioned bump is 20 μm to 350 μm; Requirement (α2): the pitch ( _BMp ) (unit: μm) of the aforementioned bump and the width ( _BMw ) (unit: μm) of the aforementioned bump satisfy the following formula (I) [( _BMp )/( _BMw )]≦0.70・・・・(I) ・Requirement (β1): The tensile modulus E'(23°C) of the protective film (X) formed by curing the curable resin film (x) at 23°C is 1×10 ⁷ Pa~1×10 ¹⁰ Pa; ・Requirement (β2): The tensile modulus E'(260°C) of the protective film (X) formed by curing the curable resin film (x) at 260°C is 1×10 ⁵ Pa~1×10 ⁸ Pa; ・Requirement (β3): The thickness (XT) (unit: μm) of the protective film (X) formed by curing the curable resin film ( _x ) at 23°C and the height ( _BMh ) (unit: μm) of the bump satisfy the following formula (II) The protective film forming sheet of claim 1 or 2, further satisfying the following requirement (α3a); Requirement (α3a): the height (BM _h ) of the bump and the width (BM _w ) of the bump satisfy the following formula (IIIa): The protective film forming sheet of claim 1 or 2, further satisfying the following requirement (α3b); Requirement (α3b): the height (BM _h ) of the bump and the width (BM _w ) of the bump satisfy the following formula (IIIb): The protective film forming sheet of claim 1 or 2, further satisfying the following requirement (α4); Requirement (α4): the height (BM _h ) of the bump is 15 μm to 300 μm. A sheet for forming a protective film as claimed in claim 1 or 2, wherein the supporting sheet (Y) is a back grinding tape. A method for manufacturing a semiconductor wafer with a protective film, comprising the following steps (S1) to (S3); ・Step (S1): preparing a semiconductor wafer having a bump forming surface on which a plurality of bumps are provided; ・Step (S2): pressing a curable resin film (x) of a protective film forming sheet as described in any one of claims 1 to 6 as an attachment surface onto the aforementioned bump forming surface of the aforementioned semiconductor wafer and attaching the same; ・Step (S3): curing the curable resin film (x) to form a protective film (X); wherein the aforementioned semiconductor wafer prepared in the aforementioned step (S1) satisfies the following requirements (α1) to (α2);・Condition (α1): the width of the aforementioned bump ( _BMw ) (unit: μm) is 20μm~350μm; ・Condition (α2): the pitch of the aforementioned bump ( _BMp ) (unit: μm) and the width of the aforementioned bump ( _BMw ) (unit: μm) satisfy the following formula (I): A method for manufacturing a semiconductor chip with a protective film, comprising the following steps (T1) to (T2); ・Step (T1): a step of implementing the manufacturing method of claim 7 to obtain a semiconductor wafer with a protective film; ・Step (T2): a step of singulating the semiconductor wafer with the protective film. A method for manufacturing a semiconductor package, comprising the following steps (U1) to (U2); ・Step (U1): a step of implementing the manufacturing method of claim 8 to obtain a semiconductor chip with a protective film; ・Step (U2): a step of electrically connecting a wiring substrate and the semiconductor chip with a protective film via the bump. The method for manufacturing a semiconductor package as claimed in claim 9 further comprises a step (U3); ・Step (U3): a step of filling a bottom filling material between the aforementioned wiring substrate and the aforementioned semiconductor chip with a protective film.

Images