CN109791887B - First protective film-forming sheet - Google Patents

Abstract

A first protective film forming sheet comprising a first base material, a buffer layer formed on the first base material, and a curable resin film formed on the buffer layer, wherein the buffer layer and the curable resin film are each produced into test pieces having a diameter of 8mm and a thickness of 1mm, the test pieces are strained under conditions of 90 ℃ and 1Hz, and when strain distribution measurement is performed for measuring shear elastic modulus G ' of the test pieces, the relationship between shear elastic modulus Gb300' of the test pieces of the buffer layer when strain of the test pieces of the buffer layer is 300% and shear elastic modulus Gc300' of the test pieces of the curable resin film when strain of the test pieces of the curable resin film is 300% is satisfied Gb300 '. Gtoreq.Gc 300 '.

Description

First protective film forming sheet

technical field

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

This application claims priority based on Japanese Patent Application No. 2016-197523 for which it applied in Japan on October 5, 2016, and uses the content here.

Background technique

So far, when mounting multi-pin LSI packages for MPUs or gate arrays on printed wiring boards, the flip chip (Flip chip) mounting method has been used. A semiconductor chip having protruding electrodes (hereinafter, referred to as "bumps" in this specification) formed of eutectic solder, high-temperature solder, gold, etc., these bumps are connected to the chip mounting substrate by the so-called flip-chip method. The corresponding terminal parts on the top face each other and contact each other for fusion/diffusion connection.

The semiconductor chip using this mounting method is formed, for example, by grinding, dicing, or singulating the surface of the semiconductor wafer on which bumps are formed on the circuit surface, which is opposite to the circuit surface (in other words, the bump formation surface). get. In the process of obtaining such a semiconductor chip, usually, for the purpose of protecting the bump forming surface of the semiconductor wafer and the bumps, a curable resin film is attached to the bump forming surface, the film is cured, and the surface of the bump is formed. A protective film is formed on the surface.

On the other hand, semiconductor devices are expected to have higher functions, and the size of semiconductor chips tends to increase. However, bumps are likely to be deformed due to warping of semiconductor chips mounted on a substrate in an enlarged size, and cracks are likely to occur particularly on bumps located at or near the ends of the semiconductor chip. It is also desired that the protective film formed on the bump formation surface suppress such breakage of the bumps.

A method of forming a protective film on a bump formation surface of a semiconductor wafer will be described with reference to FIG. 6 .

The sheet|seat 8 for protective film formation shown to Fig.6 (a) was used for formation of a protective film. The protective film forming sheet 8 is formed by sequentially laminating a buffer layer 83 and a curable resin film 82 on a base material 81 . The buffer layer 83 has a buffering effect on forces applied to the buffer layer 83 and layers adjacent thereto.

First, the protective film forming sheet 8 is disposed so that the curable resin film 82 of the protective film forming sheet 8 faces the bump forming surface 9 a of the semiconductor wafer 9 .

Next, the sheet 8 for forming a protective film is crimped on the semiconductor wafer 9, and as shown in FIG. The blocks form the face 9a. The bonding of the curable resin film 82 at this time is performed while heating the curable resin film 82 . Thus, the curable resin film 82 is in close contact with the bump formation surface 9a of the semiconductor wafer 9 and the surface 91a of the bump 91. A buffer layer 83 is also adhered to a part.

After bonding of such curable resin film 82, if necessary, after further grinding the surface (back surface) 9b of the semiconductor wafer 9 opposite to the bump formation surface 9a, the surface (back surface) 9b of the semiconductor wafer 9 is further bonded to the back surface 9b of the semiconductor wafer 9. A protective film forming sheet (illustration omitted) for protecting the rear surface 9b is attached.

Next, as shown in FIG. 6( c ), the base material 81 and the buffer layer 83 are peeled off from the curable resin film 82 .

Next, the curable resin film 82 is cured to form a protective film 82' as shown in Fig. 6(d) .

In such a method of forming the protective film, the upper portion 910 of the bump 91 must penetrate the protective film 82' and protrude. Therefore, at the stage of peeling the base material 81 and the buffer layer 83, as described above, the upper part 910 of the bump 91 penetrates the curable resin film 82 and protrudes, and the upper part 910 of the bump 91 does not remain on the curable resin film 82. status is important. On the other hand, FIG. 7 shows an example of a state where the curable resin film 82 remains on the upper portion 910 of the bump 91 . Here, an example in which the entire surface 91a of the bump 91 is covered with the curable resin film 82 is shown, but this is an example of a state where the curable resin film 82 remains. In 910 , a part of the surface 91 a is exposed without being covered with the curable resin film 82 .

As described above, the following sheet for forming a protective film is disclosed as a sheet for forming a protective film that does not leave a curable resin film on the upper portion of the bump and can form a protective film: Attaching the sheet to a semiconductor wafer A sheet for forming a protective film in which the elastic ratio of the shear storage modulus of the curable resin film to the shear storage modulus of the buffer layer at a temperature is specified within a specific range (refer to Patent Document 1). A sheet for forming a protective film in which the melt viscosity of the curable resin film is specified within a specific range at the attaching temperature of the semiconductor wafer (refer to Patent Document 2).

The sheets for forming a protective film disclosed in Patent Documents 1 and 2 all specify the physical properties of the curable resin film at the temperature when the sheet is attached to a semiconductor wafer. However, the degree of strain of the buffer layer and curable resin film constituting the sheet greatly differs between the initial stage of attachment to the semiconductor wafer and the intermediate stage. This point is obvious from FIG. 6( a ) and FIG. 6( b ). And if the degree of strain differs in this way, the physical property of a part of a buffer layer and a curable resin film will change greatly. The inventors of the present application conducted research focusing on this point, and as a result obtained the following insight: In order to suppress the residue of the curable resin film on the upper part of the bump, in the attaching stage, especially the upper part of the bump is about to be through-cured. It is important to properly adjust the physical properties of the curable resin film and the like in the middle and post-attachment stages where the curable resin film protrudes. On the other hand, none of the sheets for forming a protective film disclosed in Patent Documents 1 and 2 are configured in consideration of such a point, and there is a possibility that the effect of suppressing the residue of the curable resin film on the upper portion of the bump is insufficient.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2015-206006

Patent Document 2: Japanese Patent No. 5666335

Contents of the invention

The technical problem to be solved in the present invention

The object of the present invention is to provide a novel sheet for forming a protective film, which is provided with a curable resin film, and is used for When the protective film is formed on the surface and the curable resin film is attached to the surface, it is possible to suppress the curable resin film from remaining on the upper portion of the bump.

Technical means to solve technical problems

The present invention provides a first protective film-forming sheet comprising a first base material, a buffer layer formed on the first base material, and a curable resin film formed on the buffer layer, wherein the curable A resin film is attached to the surface of the semiconductor wafer with bumps and cured to form a first protective film on the surface. The temperature is 90° C. and the frequency is 1 Hz, so that the diameter is 8 mm and the thickness is 1 mm of the test piece of the cushioning layer is strained, and when the strain distribution measurement of the shear elastic modulus G' of the test piece of the cushioning layer is measured, the strain of the test piece of the cushioning layer is 300%. The shear elastic modulus of the test piece of the cushioning layer is Gb300', with the temperature of 90 ° C and the condition of frequency 1 Hz, the test piece of the curable resin film with a diameter of 8 mm and a thickness of 1 mm is strained and measured. When measuring the strain distribution of the shear elastic modulus G' of the test piece of the curable resin film, the shear of the test piece of the curable resin film when the strain of the test piece of the curable resin film is 300% The elastic modulus is Gc300', and the Gb300' and the Gc300' satisfy the following relationship,

Formula (w1): Gb300'≥Gc300'.

In the first sheet for forming a protective film of the present invention, the shear elastic modulus Gb200' of the test piece of the cushion layer when the strain of the test piece of the cushion layer is 200% is different from that of the curable resin film. The shear elastic modulus Gc200' of the test piece of the curable resin film when the strain of the test piece is 200% can satisfy the following relationship,

Formula (w2): Gb200'≥Gc200'.

In the first sheet for forming a protective film of the present invention, the shear elastic modulus Gb400' of the test piece of the cushion layer when the strain of the test piece of the cushion layer is 400% is different from that of the curable resin film. The shear elastic modulus Gc400' of the test piece of the curable resin film when the strain of the test piece is 400% can satisfy the following relationship,

Formula (w3): Gb400'≥Gc400'.

In the first sheet for forming a protective film of the present invention, in the function of the strain of the test piece of the buffer layer obtained by the strain distribution measurement and the shear elastic modulus Gb' of the test piece of the buffer layer , there is a region where the shear elastic modulus Gb' is not constant, and the shear elastic modulus Gb' when the strain of the test piece of the buffer layer is 300% may be included in the region.

In the first protective film-forming sheet of the present invention, the strain of the test piece of the curable resin film obtained by the strain distribution measurement and the shear modulus Gc of the test piece of the curable resin film are In the function of ', there is a region where the shear elastic modulus Gc' is not constant, and the shear elastic modulus Gc' when the strain of the test piece of the curable resin film is 300% can be included in the in the area.

In the first sheet for forming a protective film of the present invention, the curable resin film contains a resin component, the content of the filler in the curable resin film is 45% by mass or less, and the weight average molecular weight of the resin component may be Below 30000.

Invention effect

The first protective film can be formed on the surface of the semiconductor wafer by attaching the first protective film-forming sheet of the present invention to the surface having the bumps and curing the curable resin film. In addition, when the curable resin film is attached to the surface, it is possible to suppress the curable resin film from remaining on the upper portion of the bump.

Description of drawings

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

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

FIG. 3 is a cross-sectional view schematically showing an example of a method of using the first sheet for forming a protective film shown in FIG. 1 .

FIG. 4 is a cross-sectional view schematically showing an example of a method of using the first sheet for forming a protective film shown in FIG. 2 .

Fig. 5 is a graph showing the measurement results of the shear elastic modulus G' of test pieces of cushion layers and thermosetting resin films of Examples and Comparative Examples.

6 is a cross-sectional view schematically illustrating a method of forming a protective film on a bump formation surface of a semiconductor wafer.

FIG. 7 is a cross-sectional view schematically showing an example of a state where a curable resin film remains on top of a bump.

Detailed ways

◇The first protective film forming sheet

The first protective film-forming sheet of the present invention includes a first base material, a buffer layer formed on the first base material, and a curable resin film formed on the buffer layer.

The curable resin film is used to form a first protective film on the surface of the semiconductor wafer by attaching and curing the curable resin film on the surface having the bumps.

And the 1st sheet|seat for protective film formation of this invention satisfies the relationship of following formula (w1).

Gb300’≥Gc300’····(w1)

Here, Gb300' is the shear elastic modulus of the test piece of the cushion layer when the strain distribution of the test piece of the cushion layer is measured at 300%. The measurement of the strain distribution at this time is carried out in the following manner: under the conditions of a temperature of 90° C. and a frequency of 1 Hz, the test piece of the buffer layer having a diameter of 8 mm and a thickness of 1 mm is strained, and the strain of the test piece of the buffer layer is measured. Shear modulus of elasticity G'.

In addition, Gc300' is the shear elasticity of the test piece of the curable resin film when the strain distribution of the test piece of the curable resin film is measured at 300%. modulus. The strain distribution measurement at this time was performed by the same method as the case of the test piece of the said buffer layer. That is, the test piece of the curable resin film having a diameter of 8 mm and a thickness of 1 mm is strained under conditions of a temperature of 90° C. and a frequency of 1 Hz, and the shear modulus G of the test piece of the curable resin film is measured. ', from which the strain distribution measurement is performed.

As described above, all the test pieces for measuring the strain distribution are in the shape of a circular film.

The first sheet for forming a protective film of the present invention is used by affixing its curable resin film to a surface having bumps (in this specification, sometimes referred to as a "bump formation surface") of a semiconductor wafer. At this time, by attaching the curable resin film to the bump forming surface while heating, the softened curable resin film spreads between the bumps so as to cover the bumps, closely adheres to the bump forming surface, and simultaneously covers the bumps. The surface of the bump, especially the surface of the vicinity of the bump forming surface is covered to fill the bump. Thereafter, the curable resin film in this state is finally cured to form a first protective film. In addition, the first protective film protects the bump forming surface and the bumps in a state of being in close contact with the bump forming surface and the surface of the bump. For the semiconductor wafer on which the sheet for forming the first protective film is attached, for example, after grinding the surface opposite to the bump formation surface, the first base material and the buffer layer are removed, and further, after forming the first protective film, Finally, it is mounted in a semiconductor device in the state of a semiconductor chip provided with the first protective film.

By using the first protective film forming sheet of the present invention, when the curable resin film is attached to the bump formation surface of the semiconductor wafer, it is possible to suppress the curable resin film remaining on the bump upper portion. This is because the curable resin film and the buffer layer satisfy the relationship of the above formula (w1). After the middle stage of attaching the first protective film forming sheet to the semiconductor wafer, by making them (cured The shear modulus of elasticity of the curable resin film and cushion layer) has the specific relationship as described above, and the upper portion of the bump can easily penetrate through the curable resin film and protrude.

The first sheet for forming a protective film satisfies the relationship of the above formula (w1). That is, the buffer layer and the curable resin film constituting the first protective film forming sheet were each prepared as a test piece with a diameter of 8 mm and a thickness of 1 mm, and these test pieces were made under the conditions of a temperature of 90° C. and a frequency of 1 Hz. Strain was generated, and strain distribution measurement for measuring the shear elastic modulus G' of these test pieces was performed. At this time, in the present invention, the shear elastic modulus Gb300′ of the test piece of the cushion layer when the strain of the test piece of the cushion layer is 300% and the curable resin when the strain of the test piece of the curable resin film is 300% The shear elastic modulus Gc300' of the film test piece satisfies the relationship of Gb300'≥Gc300'.

When the first sheet for forming a protective film is attached to the bump formation surface of the semiconductor wafer, the degree of strain of the buffer layer constituting the sheet and the curable resin The degree of strain of the membranes varies widely. This is the reason why the values (Gb300', Gc300') at the strain of 300% of these test pieces are used as the shear elastic modulus G' of the test pieces of the buffer layer and the curable resin film in order to define the present invention. If the degree of strain of the buffer layer is different, some of its physical properties will change greatly. Similarly, if the degree of strain of the curable resin film is different, some of its physical properties will also greatly change. When attaching the curable resin film to the bump forming surface, in order to suppress the residue of the curable resin film on the upper part of the bump, in the step of attaching the curable resin film, especially just before the upper part of the bump In the stage where the curable resin film protrudes (in other words, the stage after the middle stage of attachment, or the stage where the degree of strain of the buffer layer and the curable resin film increases to some extent), the buffer layer and the curable resin film are specified. The relationship of the shear modulus G' is important. Therefore, the present invention satisfies the relationship of the above formula (w1). Gb300' and Gc300' are the shear elastic modulus G' at the stage where the degree of strain of the buffer layer and the curable resin film has become large, respectively.

The first sheet for forming a protective film only needs to satisfy the relationship of the above formula (w1), in other words, the value of Gb300'/Gc300' is 1 or more. From the viewpoint of further enhancing the above-mentioned effects of the present invention, the value of Gb300'/Gc300' is preferably greater than 1, more preferably 10 or more, still more preferably 100 or more, for example, may be 1000 or more.

In the first sheet for forming a protective film, both the shear modulus G' of the buffer layer and the shear modulus G' of the test piece of the buffer layer can be adjusted by adjusting the type or composition of the buffer layer. content and easily adjusted. Therefore, it is only necessary to adjust the types or contents of components contained in the composition for forming a buffer layer described later for forming a buffer layer. For example, it is preferable to adjust the polyα-olefin in the composition (V) for forming a buffer layer described later. Such as the type or content of the main ingredients.

In the sheet for forming the first protective film, both the shear modulus G' of the curable resin film and the shear modulus G' of the test piece of the curable resin film can be adjusted by adjusting the It is easy to adjust the type or content of the ingredients contained in it. Therefore, what is necessary is just to adjust the kind and content of the component contained in the curable resin film forming composition mentioned later for forming a curable resin film. For example, when using the resin layer-forming composition (III) described later, it is preferable to adjust the polymer component (A), thermosetting component (B), curing accelerator (C) or filler (D) in the composition. The type or content of the main ingredients.

When performing the strain distribution measurement, it is more preferable that the first sheet for forming a protective film satisfies the relationship of the following formula (w2).

Gb200’≥Gc200’····(w2)

Here, Gb200' is the shear elastic modulus of the test piece of the cushion layer when the strain of the test piece of the cushion layer is 200%. In addition, Gc200' is the shear elastic modulus of the curable resin film test piece when the strain of the curable resin film test piece is 200%.

When the curable resin film of the first protective film forming sheet satisfying the relationship of the above formula (w2) is attached to the bump forming surface, the effect of suppressing the residue of the curable resin film on the upper part of the bump is further improved. be improved.

The first sheet for forming a protective film preferably satisfies the relationship of the above formula (w2), in other words, the value of Gb200'/Gc200' is preferably 1 or more. From the viewpoint of further enhancing the above-mentioned effects of the present invention, the value of Gb200'/Gc200' is more preferably greater than 1, still more preferably 10 or more, particularly preferably 100 or more, for example, may be 1000 or more.

When performing the strain distribution measurement, it is more preferable that the first sheet for forming a protective film satisfies the relationship of the following formula (w3).

Gb400’≥Gc400’····(w3)

Here, Gb400' is the shear elastic modulus of the test piece of the cushion layer when the strain of the test piece of the cushion layer is 400%. In addition, Gc400' is the shear elastic modulus of the curable resin film test piece when the strain of the curable resin film test piece is 400%.

When the curable resin film of the first protective film forming sheet satisfying the relationship of the above formula (w3) is attached to the bump forming surface, the effect of suppressing the residue of the curable resin film on the upper part of the bump is further improved. be improved.

The first sheet for forming a protective film preferably satisfies the relationship of the above formula (w3), in other words, the value of Gb400'/Gc400' is preferably 1 or more. From the viewpoint of further enhancing the above-mentioned effects of the present invention, the value of Gb400'/Gc400' is more preferably greater than 1, still more preferably 10 or more, particularly preferably 100 or more, for example, may be 1000 or more.

From the viewpoint of further enhancing the above-mentioned effects of the present invention, it is preferable that the first protective film-forming sheet satisfies the relationship of the above-mentioned formula (w1) and satisfies at least one of the above-mentioned formulas (w2) and (w3). It is more preferable to satisfy the relationship of the above formulas (w1), (w2) and (w3) at the same time.

For the first protective film forming sheet, the strain of the test piece of the buffer layer obtained by the strain distribution measurement and the function of the shear elastic modulus Gb' of the test piece of the buffer layer (in this specification , sometimes referred to as "function Fb"), preferably there is a region where the shear elastic modulus Gb' is not constant (in this specification, sometimes referred to as "fluctuation region Rb"), more preferably the strain of the test piece of the cushioning layer is The shear elastic modulus Gb' at 300% is included in the region (variation region Rb). When the curable resin film of such a 1st protective film forming sheet is attached to the said bump formation surface, the effect of suppressing the curable resin film remaining on the upper part of a bump is further enhanced.

For the first protective film forming sheet, the strain of the test piece of the curable resin film obtained by the strain distribution measurement is a function of the shear modulus Gc' of the test piece of the curable resin film ( In this specification, it may be referred to as "function Fc"), preferably there is a region where the shear modulus Gc' is not constant (in this specification, it may be referred to as "fluctuation region Rc"), and it is more preferable that the curable resin film The shear elastic modulus Gc' when the strain of the test piece is 300% is included in the above region (fluctuation region Rc). When the curable resin film of such a 1st protective film forming sheet is attached to the said bump formation surface, the effect of suppressing the curable resin film remaining on the upper part of a bump is further enhanced.

From the viewpoint of further enhancing the above-mentioned effects of the present invention, the first sheet for forming a protective film preferably has a fluctuation region Rb in the function Fb and a fluctuation region Rc in the function Fc, More preferably, the shear modulus Gb' when the strain of the test piece of the buffer layer is 300% is included in the fluctuation region Rb, and the shear modulus Gc' when the strain of the test piece of the curable resin film is 300% Included in the change region Rc.

In addition, in this specification, "the shear elastic modulus is not constant" means that "the minimum value (Pa) of the shear elastic modulus is less than 90% of the maximum value (Pa) of the shear elastic modulus" in the target area. (The value of [the minimum value of the shear elastic modulus (Pa)]/[the maximum value of the shear elastic modulus (Pa)]×100 is less than 90)”. In other words, "the shear modulus is constant" means that "the minimum value (Pa) of the shear modulus is 90% or more of the maximum value (Pa) of the shear modulus" in the target region.

In the function Fb of the first protective film-forming sheet, the presence or absence of the fluctuation region Rb can be easily adjusted by adjusting the type or content of the components contained in the buffer layer, as in the case of the above-mentioned shear elastic modulus G'.

In the function Fc of the first protective film-forming sheet, as in the case of the above-mentioned shear modulus G', the presence or absence of the variable region Rb can be easily adjusted by adjusting the type or content of the components contained in the curable resin film. .

FIG. 1 is a cross-sectional view schematically showing one embodiment of a first sheet for forming a protective film of the present invention. In addition, in order to make the features of the present invention easier to understand, important parts of the drawings used in the following description may be shown enlarged for convenience, and the dimensional ratios of the respective components may not necessarily be the same as the actual ones.

The first sheet for forming a protective film shown in FIG. 1 includes a first base material 11 , a buffer layer 13 formed on the first base material 11 , and a curable resin film 12 formed on the buffer layer 13 .

More specifically, in the first sheet 1 for forming a protective film, a cushion layer 13 is laminated on one surface (hereinafter, sometimes referred to as "first surface") 11a of the first base material 11. Curable resin film 12 is laminated on surface (hereinafter, sometimes referred to as "first surface") 13a opposite to the side on which first base material 11 is provided. As mentioned above, the 1st sheet|seat 1 for protective film formation is laminated|stacked sequentially along the thickness direction of the 1st base material 11, the buffer layer 13, and the curable resin film 12. In FIG. 1 , reference numeral 12 a denotes a surface (hereinafter, sometimes referred to as "first surface") of the curable resin film 12 opposite to the side on which the buffer layer 13 is provided.

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

In addition, in the figures after FIG. 2 , the same reference numerals as those shown in the already-described figures are assigned to the same components as those shown in the already-described figures, and detailed description thereof will be omitted.

The sheet 2 for forming a first protective film shown in FIG. Except for the buffer layer 13 on the lamination layer 14), it is the same as the first protective film forming sheet 1 shown in FIG. 1 .

That is, in the first sheet 2 for forming a protective film, the adhesive layer 14 is laminated on the first surface 11a of the first base material 11, and the side of the adhesive layer 14 on which the first base material 11 is provided is the opposite side. A cushion layer 13 is laminated on the surface (hereinafter, sometimes referred to as "first surface") 14a, and the first protective film forming sheet 2 is composed of a first base material 11, an adhesive layer 14, a cushion layer 13 and a curable resin film. 12 are stacked sequentially along their thickness direction.

The sheet for forming the first protective film of the present invention is not limited to the sheet for forming shown in FIGS. 1 and 2 , and the sheet for forming shown in FIGS. Changes, deletions or additions are made to a part of the composition.

For example, the first sheet for forming a protective film of the present invention may have a release layer on the outermost layer (the curable resin film 12 in the sheet for forming a first protective film shown in FIGS. 1 and 2 ) on the side opposite to the substrate. membrane.

Next, each layer which comprises the 1st sheet|seat for protective film formation of this invention is demonstrated.

◎The first substrate

The first base material is in the form of a sheet or a film, and various resins are exemplified as its constituent material.

Examples of the resin include polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polypropylene, polybutene, polybutadiene, Polymethylpentene, norbornene resin and other polyolefins other than polyethylene; ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer, ethylene- Ethylene-based copolymers such as norbornene copolymers (copolymers obtained by using ethylene as a monomer); vinyl chloride-based resins such as polyvinyl chloride and vinyl chloride copolymers (resins obtained by using vinyl chloride as a monomer); Styrene; Polycycloolefin; Polyethylene terephthalate, Polyethylene naphthalate, Polybutylene terephthalate, Polyethylene isophthalate, Polyethylene 2,6 -Polyesters such as ethylene naphthalate and wholly aromatic polyesters whose structural units have aromatic ring groups; copolymers of two or more of the above-mentioned polyesters; poly(meth)acrylates; polyurethanes ; Polyurethane acrylate; Polyimide; Polyamide; Polycarbonate; Fluorine resin; Polyacetal; Modified polyphenylene ether; Polyphenylene sulfide; Polysulfone;

Moreover, as said resin, polymer alloys, such as the mixture of the said polyester and resin other than it, are mentioned, for example. It is preferable that the amount of the resin other than the polyester in the polymer alloy of the polyester and the other resin is relatively small.

In addition, as the above-mentioned resin, for example, a cross-linked resin obtained by cross-linking one or two or more of the above-mentioned resins; using one or two of the above-mentioned resins Modified resins such as ionomers above.

In addition, in this specification, "(meth)acryl" is a concept including both "acryl" and "methacryl". Terms similar to (meth)acrylic acid are also the same, for example, "(meth)acrylate" is a concept that includes both "acrylate" and "methacrylate", and "(meth)acryloyl" is a general formula Contains the concepts of "acryloyl" and "methacryloyl".

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

The first substrate may be one layer (single layer), or multiple layers of two or more layers. When multiple layers are used, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited. .

In addition, in this specification, not limited to the case of the first base material, "a plurality of layers may be the same or different" means "all the layers may be the same, all the layers may be different, or only a part of the layers may be The same", and "a plurality of layers are different from each other" means "at least one of the constituent materials and thicknesses of the respective layers are different from each other".

The thickness of the first substrate is preferably 5 to 1000 μm, more preferably 10 to 500 μm, still more preferably 15 to 300 μm, particularly preferably 20 to 150 μm.

Here, the "thickness of the first base material" means the thickness of the entire first base material, for example, the thickness of the first base material composed of a plurality of layers means the total thickness of all the layers constituting the first base material.

It is preferable that the first base material is a base material with high thickness accuracy, that is, a base material in which variation in thickness can be suppressed at any point. Among the above constituent materials, materials that can be used as the first base material with high thickness accuracy include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, ethylene terephthalate, etc. - vinyl acetate copolymers and the like.

The first base material may contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, softeners (plasticizers), and the like in addition to the main constituent materials such as the above-mentioned resins.

The first base material may be transparent or opaque, may be colored according to the purpose, and may have other layers deposited thereon.

When the curable resin film is energy ray curable, it is preferable that the first base material transmits energy ray.

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

◎Buffer layer

The buffer layer acts as a buffer against forces applied to the buffer layer and layers adjacent thereto. Here, the "layer adjacent to the buffer layer" mainly refers to the curable resin film and the first protective film corresponding to its cured product.

The buffer layer is in the form of a sheet or a film, and its constituent material is not particularly limited as long as it satisfies the relationship of the above formula (w1).

As a preferable cushion layer, the cushion layer containing various resins, such as poly-alpha-olefin, is mentioned, for example.

The buffer layer may be one layer (single layer) or multiple layers of two or more layers. When multiple layers are used, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

The thickness of the buffer layer is preferably 150 to 1000 μm, more preferably 150 to 800 μm, still more preferably 200 to 600 μm, particularly preferably 250 to 500 μm.

Here, the "thickness of the buffer layer" refers to the thickness of the entire buffer layer, for example, the thickness of a buffer layer composed of a plurality of layers refers to the total thickness of all the layers constituting the buffer layer.

＜＜Composition for buffer layer＞＞

The buffer layer can be formed using a composition for forming a buffer layer containing a constituent material of the buffer layer such as the resin described above. For example, a cushion layer can be formed at a target site by extrusion-molding the cushion layer-forming composition on the surface to be formed of the cushion layer. A more specific method of forming the buffer layer will be described in detail later together with methods of forming other layers. The content ratio of the components which do not vaporize at normal temperature in the composition for forming a buffer layer is usually the same as the content ratio of the above-mentioned components of the buffer layer. In addition, in this specification, "normal temperature" means the temperature which does not perform cooling or heating in particular, that is, normal temperature, For example, the temperature of 15-25 degreeC, etc. are mentioned.

<Composition for buffer layer formation (V)>

As a buffer layer forming composition, the buffer layer forming composition (V) etc. which contain poly (alpha)-olefin are mentioned, for example.

The polyα-olefin may be a polyα-olefin having a structural unit derived from an α-olefin.

The structural unit of polyα-olefin may be only one kind, or may be two or more kinds, and when there are two or more kinds, their combination and ratio can be selected arbitrarily. That is, the polyα-olefin may be a homopolymer obtained by polymerizing one type of monomer, or may be a copolymer obtained by copolymerizing two or more types of monomers.

Preferably the polyalphaolefin is an ethylene-alpha-olefin copolymer.

The density of polyα-olefin is preferably 890 kg/m ³ or less, more preferably 830-890 kg/m ³ , particularly preferably 850-875 kg/m ³ . In addition, in this specification, unless otherwise stated, "the density of a polyα-olefin" means the value measured based on ASTM D1505.

The polyα-olefin has a melting point of preferably 55°C or lower, more preferably 50°C or lower.

The melt flow rate (MFR) of the polyα-olefin at 190° C. is preferably 1 to 6 g/10 minutes, more preferably 2.5 to 4.5 g/10 minutes.

In addition, the melt flow rate (MFR) at 230° C. of the polyα-olefin is preferably 2 to 12 g/10 minutes, more preferably 4 to 9 g/10 minutes.

In addition, in this specification, "the melt flow rate of a polyα-olefin" means the value measured based on ASTMD1238 unless otherwise stated.

It is preferable that content of the polyα-olefin of the composition (V) for buffer layer formation and a buffer layer is 80-100 mass %.

[other ingredients]

The buffer layer-forming composition (V) and the buffer layer may contain components other than polyα-olefin as long as the effects of the present invention are not impaired.

These other components are not particularly limited and may be appropriately selected according to purposes.

The buffer layer-forming composition (V) and the other components contained in the buffer layer may be one type only, or two or more types may be used. When there are two or more types, their combination and ratio may be selected arbitrarily.

The content of the composition (V) for buffer layer formation and the said other component of a buffer layer is not specifically limited, What is necessary is just to select suitably according to the objective.

◎Curable resin film

The curable resin film is a layer for protecting the bump formation surface (in other words, the circuit surface) of the semiconductor wafer and the bumps provided on the bump formation surface, and is a thermosetting resin film in the first embodiment, and is a thermosetting resin film in the second embodiment. In an embodiment, it is an energy ray curable resin film. The curable resin film is cured to form a first protective film.

The curable resin film is in the form of a sheet or a film, and its constituent material is not particularly limited as long as it satisfies the relationship of the above formula (w1).

The curable resin may be either thermosetting or energy ray curable, but is preferably thermosetting.

In addition, in this specification, an "energy ray" means a ray having energy quanta in an electromagnetic wave or a charged particle beam, and examples thereof include ultraviolet rays, radiation, electron beams, and the like.

Ultraviolet rays can be irradiated by using, for example, a high-pressure mercury lamp, a fusion H lamp, a xenon lamp, a black light lamp, an LED lamp, or the like as an ultraviolet light source. The electron beam can be irradiated with an electron beam generated by an electron beam accelerator or the like.

In the present specification, "energy ray curability" refers to the property of curing by irradiation of energy rays, and "non-energy ray curability" refers to the property of not curing even when irradiated with energy rays.

The curable resin film contains a resin component, may contain fillers other than the resin component, or may not contain fillers other than the resin component, and the content of the filler is preferably 45% by mass or less.

In the curable resin film, the weight average molecular weight of the resin component is preferably 1,000,000 or less, and may be, for example, 800,000 or less, 500,000 or less, 300,000 or less, 200,000 or less, 100,000 or less, 50,000, or 30,000 or less.

On the other hand, in the curable resin film, the lower limit of the weight average molecular weight of the resin component is not particularly limited, and may be either 5,000 or 8,000, for example.

When the above-mentioned resin component satisfies these respective conditions, the effect of suppressing the curable resin film remaining on the upper portion of the bump by the first sheet for forming a protective film is further enhanced.

In addition, in this specification, unless otherwise stated, a weight average molecular weight is the polystyrene conversion value measured by the gel permeation chromatography (GPC) method.

The weight average molecular weight of the resin component can be appropriately adjusted so that the weight average molecular weight of the resin component becomes a value within a range set by arbitrarily combining the above-mentioned preferable lower limit and upper limit.

As a preferable example of the said weight average molecular weight, 5000-1000000, 5000-800000, 5000-500000, 5000-300000, 5000-200000, 5000-100000, 5000-50000, and 5000-30000 are mentioned, for example.

As another preferable example of the said weight average molecular weight, 8000-1000000, 8000-800000, 8000-500000, 8000-300000, 8000-200000, 8000-100000, 8000-50000, and 8000-30000 are mentioned, for example.

However, the weight average molecular weight is not limited thereto.

The content of the filler in the curable resin film is more preferably 40% by mass or less, particularly preferably 30% by mass or less.

On the other hand, the lower limit of the content of the filler in the curable resin film is not particularly limited. For example, the content of the filler in the curable resin film may be any one of 0% by mass or more, 5% by mass or more, and 10% by mass or more.

The content of the filler in the curable resin film can be appropriately adjusted so that the content of the filler in the curable resin film becomes a value within a range set by arbitrarily combining the above-mentioned preferred lower limit and upper limit.

As a preferable example of content of the filler of a curable resin film, 0-45 mass %, 0-40 mass %, and 0-30 mass % etc. are mentioned.

However, content of the filler of a curable resin film is not limited to this.

It is particularly preferable that the curable resin film contains a resin component, the content of the filler is 45% by mass or less, and the weight average molecular weight of the resin component is 30000 or less. By satisfying such a condition, the effect of suppressing the curable resin film remaining on the bump upper part by the 1st sheet|seat for protective film formation becomes more high.

The types of the resin component and filler are not particularly limited.

Such a curable resin film includes, for example, a resin component, and the content of the filler is preferably 0 to 45% by mass, more preferably 0 to 40% by mass, and even more preferably 0 to 30% by mass. A curable resin film having a weight average molecular weight of 30,000 or less (for example, 5,000 to 30,000, 8,000 to 30,000, etc.).

A curable resin film can be formed using the composition for curable resin film formation containing the constituent material. For example, all the components corresponding to the resin in the thermosetting resin film forming composition and the energy ray curable resin film forming composition mentioned later are contained in the said resin component.

○Thermosetting resin film

As a preferable thermosetting resin film, the thermosetting resin film which contains a polymer component (A) as said resin component, and further contains a thermosetting component (B) is mentioned, for example.

The thermosetting resin film may be only one layer (single layer), or may be multiple layers of two or more layers. When multiple layers are used, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited. .

The thickness of the thermosetting resin film is preferably 1 to 100 μm, more preferably 5 to 75 μm, particularly preferably 5 to 50 μm. By making the thickness of a thermosetting resin film more than the said lower limit, the 1st protective film with higher protective ability can be formed. Moreover, it can suppress that thickness becomes excessive thickness by making the thickness of a thermosetting resin film below the said upper limit.

Here, the "thickness of the thermosetting resin film" refers to the thickness of the entire thermosetting resin film, for example, the thickness of a thermosetting resin film composed of a plurality of layers refers to the total thickness of all the layers constituting the thermosetting resin film.

＜＜Thermosetting resin film forming composition＞＞

A thermosetting resin film can be formed using the composition for forming a thermosetting resin film containing the constituent material. For example, a thermosetting resin film can be formed on a target site by applying the composition for forming a thermosetting resin film on a surface to be formed of a thermosetting resin film and drying as necessary. A more specific method of forming the thermosetting resin film will be described in detail later together with methods of forming other layers. The content ratio of the components which do not vaporize at normal temperature in the thermosetting resin film forming composition is normally the same as the content ratio of the said components of a thermosetting resin film.

Coating of the composition for forming a thermosetting resin film may be performed by a known method, for example, use of an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife Various coating methods such as coater, curtain coater, die coater, knife coater, screen coater, Meyer rod coater, kiss coater (kiss coater).

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

<Resin layer forming composition (III)>

As a thermosetting resin film-forming composition, for example, a thermosetting resin film-forming composition (III) containing a polymer component (A) and a thermosetting component (B) (in this specification, sometimes abbreviated as "resin layer forming With composition (III)") and the like.

[Polymer component (A)]

The polymer component (A) is a polymer compound for imparting film-forming properties, flexibility, etc. to a thermosetting resin film, and is regarded as a component formed by polymerizing a polymerizable compound. In addition, polycondensation reaction is also included in the polymerization reaction in this specification.

The polymer component (A) contained in the resin layer forming composition (III) and the thermosetting resin film may be only one kind, or may be two or more kinds. When there are two or more kinds, their combination and ratio can be selected arbitrarily.

As a polymer component (A), an acrylic resin (resin which has a (meth)acryloyl group), polyvinyl acetal, etc. are mentioned, for example.

Examples of the acrylic resin in the polymer component (A) include known acrylic polymers.

The weight average molecular weight (Mw) of an acrylic resin becomes like this. Preferably it is 5,000-1,000,000, More preferably, it is 8,000-800,000. When the weight average molecular weight of the acrylic resin is in such a range, when the curable resin film is attached to the bump formation surface, the effect of suppressing the curable resin film remaining on the bump upper portion is further enhanced.

The glass transition temperature (Tg) of the acrylic resin is preferably -50 to 70°C, more preferably -30 to 60°C. By setting the Tg of the acrylic resin in such a range, the effect of suppressing the curable resin film remaining on the bump upper portion when the curable resin film is attached to the bump formation surface is further enhanced.

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

As the acrylic resin, for example, one or more polymers of (meth)acrylates can be cited;

A copolymer of two or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide;

One or two or more (meth)acrylates and one or two selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene and N-methylolacrylamide, etc. Copolymers of more than one monomer, etc.

Examples of the (meth)acrylate constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso(meth)acrylate, Propyl ester, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, (methyl) ) hexyl acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate ester, isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), Tridecyl (meth)acrylate, Myristyl (meth)acrylate (myristyl (meth)acrylate), Pentadecyl (meth)acrylate, Cetyl (meth)acrylate Alkyl esters (palm (meth)acrylate), heptadecyl (meth)acrylate, stearyl (meth)acrylate (stearyl (meth)acrylate), etc. The alkyl group of the base ester is an alkyl (meth)acrylate with a chain structure of 1 to 18 carbon atoms;

Cycloalkyl (meth)acrylates such as isobornyl (meth)acrylate and dicyclopentyl (meth)acrylate;

Aralkyl (meth)acrylates such as benzyl (meth)acrylate;

Cycloalkenyl (meth)acrylate such as dicyclopentenyl (meth)acrylate;

Cycloalkenyloxyalkyl (meth)acrylates such as dicyclopentenyloxyethyl (meth)acrylate;

(meth)acrylimide;

Glycidyl (meth)acrylate and other glycidyl-containing (meth)acrylates;

Hydroxymethyl (meth)acrylate, 2-Hydroxyethyl (meth)acrylate, 2-Hydroxypropyl (meth)acrylate, 3-Hydroxypropyl (meth)acrylate, 2-Hydroxy (meth)acrylate Butyl, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and other hydroxyl-containing (meth)acrylates;

Substituted amino group-containing (meth)acrylates such as N-methylaminoethyl (meth)acrylate, etc. Here, the "substituted amino group" refers to a group in which one or two hydrogen atoms of the amino group are replaced by groups other than hydrogen atoms.

Acrylic resins may have functional groups such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups that can be bonded to other compounds. The functional group of the acrylic resin may be bonded to another compound through a crosslinking agent (F) described later, or may be bonded directly to another compound without passing through a crosslinking agent (F). The acrylic resin is bonded to another compound through the functional group, and the reliability of the package obtained by using the first sheet for forming a protective film tends to be improved.

Examples of the polyvinyl acetal in the polymer component (A) include known polyvinyl acetals.

Among these, polyvinyl formal, polyvinyl butyral, etc. are mentioned as preferable polyvinyl acetal, and polyvinyl butyral is more preferable.

Examples of polyvinyl butyral include polyvinyl butyral having structural units represented by the following formulas (i)-1, (i)-2, and (i)-3.

[chemical formula 1]

In the formula, l, m and n are each independently an integer of 1 or more.

The weight average molecular weight (Mw) of polyvinyl acetal is preferably 5,000 to 200,000, more preferably 8,000 to 100,000. When the weight-average molecular weight of polyvinyl acetal is within such a range, when the curable resin film is attached to the bump formation surface, the effect of suppressing the residue of the curable resin film on the upper portion of the bump is further enhanced. .

The glass transition temperature (Tg) of polyvinyl acetal is preferably 40 to 80°C, more preferably 50 to 70°C. When the Tg of polyvinyl acetal falls within such a range, the effect of suppressing the curable resin film remaining on the bump upper portion when the curable resin film is attached to the bump formation surface is further enhanced.

The ratio of three or more monomers constituting polyvinyl acetal can be selected arbitrarily.

In the composition (III) for forming a resin layer, regardless of the type of the polymer component (A), the ratio of the content of the polymer component (A) to the total content of all components except the solvent (ie, thermosetting The polymer component (A) content) of the resin film is preferably 5 to 25% by mass, more preferably 5 to 15% by mass.

[Thermosetting component (B)]

The thermosetting component (B) is a component for forming a hard first protective film by curing the thermosetting resin film using heat as a reaction trigger.

The thermosetting component (B) contained in the resin layer-forming composition (III) and the thermosetting resin film may be one kind only, or two or more kinds. When there are two or more kinds, their combination and ratio can be selected arbitrarily.

Preferably, the thermosetting component (B) is an epoxy-based thermosetting resin.

(epoxy thermosetting resin)

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

The epoxy-based thermosetting resin contained in the resin layer forming composition (III) and the thermosetting resin film may be only one kind, or may be two or more kinds. When there are two or more kinds, their combination and ratio can be selected arbitrarily.

·Epoxy resin (B1)

Examples of the epoxy resin (B1) include known epoxy resins, such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydride, o-cresol novolak ring Oxygen resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin, etc. compound.

The epoxy resin (B1) may be an epoxy resin having an unsaturated hydrocarbon group. An epoxy resin having an unsaturated hydrocarbon group has higher compatibility with an acrylic resin than an epoxy resin not having an unsaturated hydrocarbon group. Therefore, by using the epoxy resin which has an unsaturated hydrocarbon group, the reliability of the package obtained using the 1st sheet|seat for protective film formation improves.

As an epoxy resin which has an unsaturated hydrocarbon group, the compound which converted some epoxy groups of a polyfunctional epoxy resin to the group which has an unsaturated hydrocarbon group is mentioned, for example. Such a compound can be obtained, for example by making (meth)acrylic acid or its derivative(s) add-react with an epoxy group.

Moreover, as an epoxy resin which has an unsaturated hydrocarbon group, the compound etc. which the group which has an unsaturated hydrocarbon group directly bonded to the aromatic ring etc. which comprise an epoxy resin are mentioned, for example.

The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include ethylene (vinyl), 2-propenyl (allyl), (meth)acryloyl, (methyl) Acrylamide group etc., preferably acryloyl group.

The number average molecular weight of the epoxy resin (B1) is not particularly limited, but is preferably 300 to 30000, more preferably 400 to 10000, from the viewpoint of the curability of the thermosetting resin film and the strength and heat resistance of the first protective film, Especially preferably, it is 500-3000.

The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1000 g/eq, more preferably 300 to 800 g/eq.

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

·Heat curing agent (B2)

The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1).

As a thermosetting agent (B2), the compound which has two or more functional groups which can react with an epoxy group in 1 molecule is mentioned, for example. As said functional group, for example, a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, a group obtained by acid anhydride of an acid group, etc. are mentioned, Preferably it is a group obtained by an acid anhydride of a phenolic hydroxyl group, an amino group or an acid group, More preferably, it is a phenolic hydroxyl group or amino group.

Examples of the phenolic curing agent having a phenolic hydroxyl group in the thermosetting agent (B2) include polyfunctional phenolic resins, biphenol, novolak-type phenolic resins, dicyclopentadiene-based phenolic resins, arane phenolic resin, etc.

As an amine hardening agent which has an amino group in a thermosetting agent (B2), dicyandiamide (it may abbreviate as "DICY" below) etc. are mentioned, for example.

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

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

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

The number average molecular weight of resin components such as polyfunctional phenol resin, novolak type phenol resin, dicyclopentadiene type phenol resin, aralkylphenol resin, etc. in the thermosetting agent (B2) is preferably 300 to 30000, more preferably 400-10000, particularly preferably 500-3000.

The molecular weight of non-resin components, such as biphenol and dicyandiamide, in a thermosetting agent (B2) is not specifically limited, For example, 60-500 are preferable.

One type of thermosetting agent (B2) may be used alone, or two or more types may be used in combination, and when two or more types are used in combination, their combination and ratio can be selected arbitrarily.

In the resin layer forming composition (III) and the thermosetting resin film, the content of the thermosetting agent (B2) is preferably 0.1 to 500 parts by mass, more preferably 1-200 mass parts, For example, any one of 1-150 mass parts, 1-100 mass parts, and 1-75 mass parts may be sufficient. Hardening of a thermosetting resin film will progress more easily by making the said content of a thermosetting agent (B2) more than the said lower limit. Moreover, the moisture absorption rate of a thermosetting resin film will fall by making the said content of a thermosetting agent (B2) below the said upper limit, and the reliability of the package obtained using the 1st sheet|seat for protective film formation will improve further.

In the resin layer forming composition (III) and the thermosetting resin film, the content of the thermosetting component (B) (for example, epoxy resin (B1) and thermosetting The total content of the agent (B2)) is preferably 600 to 1000 parts by mass. By setting the content of the thermosetting component (B) in such a range, the effect of suppressing the curable resin film remaining on the bump upper portion is further enhanced, and a hard first protective film can be formed.

Furthermore, it is preferable to appropriately adjust the content of the thermosetting component (B) according to the type of the polymer component (A) from the viewpoint that such an effect can be obtained more remarkably.

For example, when the polymer component (A) is the acrylic resin, in the resin layer forming composition (III) and the thermosetting resin film, the thermosetting component ( The content of B) is preferably 700 to 1000 parts by mass, more preferably 750 to 1000 parts by mass, particularly preferably 750 to 900 parts by mass.

For example, when the polymer component (A) is the above-mentioned polyvinyl acetal, in the resin layer forming composition (III) and the thermosetting resin film, with respect to the content of the polymer component (A) of 100 parts by mass, the thermosetting property The content of the component (B) is preferably 600 to 1000 parts by mass, more preferably 650 to 1000 parts by mass, particularly preferably 650 to 950 parts by mass.

[Curing Accelerator (C)]

The resin layer forming composition (III) and the thermosetting resin film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of the resin layer forming composition (III).

As a preferred curing accelerator (C), for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol; Imidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethyl Imidazoles such as imidazole (imidazole with more than one hydrogen atom replaced by groups other than hydrogen atoms); organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (more than one hydrogen atom replaced by Phosphine substituted with organic groups); tetraphenylboron tetraphenylphosphine, triphenylphosphinetetraphenylborate and other tetraphenylboron salts, etc.

The curing accelerator (C) contained in the resin layer forming composition (III) and the thermosetting resin film may be only one kind, or may be two or more kinds. When there are two or more kinds, their combination and ratio can be selected arbitrarily.

When using a curing accelerator (C), the content of the curing accelerator (C) is preferably 0.01 to 100 parts by mass of the content of the thermosetting component (B) in the resin layer forming composition (III) and the thermosetting resin film. 10 parts by mass, more preferably 0.1 to 5 parts by mass. By making the said content of a hardening accelerator (C) more than the said lower limit, the effect by using a hardening accelerator (C) can be acquired more notably. In addition, by making the content of the curing accelerator (C) below the above-mentioned upper limit, for example, the highly polar curing accelerator (C) can be suppressed from disintegrating into the thermosetting resin film and the substrate under the conditions of high temperature and high humidity. The effect of moving and segregating the adhesive interface side of the sticky substance is improved, and the reliability of the package obtained by using the first sheet for forming a protective film is further improved.

[Filler (D)]

The resin layer forming composition (III) and the thermosetting resin film may contain a filler (D). By making a thermosetting resin film contain a filler (D), adjustment of the thermal expansion coefficient of the 1st protective film obtained by hardening a thermosetting resin film becomes easy. For example, by optimizing the coefficient of thermal expansion of the first protective film with respect to the object to be formed of the first protective film, the reliability of the package obtained by using the first protective film forming sheet is further improved. Moreover, by making a thermosetting resin film contain a filler (D), the moisture absorption rate of a 1st protective film can also be reduced, or heat dissipation can be improved.

The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler.

Examples of preferred inorganic fillers include powders such as silica, alumina, talc, calcium carbonate, titanium dioxide, iron oxide, silicon carbide, and boron nitride; beads obtained by spheroidizing these inorganic fillers; Surface modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers, etc.

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

The resin layer-forming composition (III) and the filler (D) contained in the thermosetting resin film may be one type only, or two or more types may be used. When there are two or more types, their combination and ratio can be selected arbitrarily.

In the composition (III) for forming a resin layer, the ratio of the content of the filler (D) to the total content of all components except the solvent (that is, the content of the filler (D) of the thermosetting resin film) is preferably It is 45 mass % or less (0-45 mass %). By setting the content of the filler (D) within such a range, the effect of suppressing the curable resin film remaining on the bump upper portion is further enhanced.

On the other hand, when the filler (D) is used, in the composition (III) for forming a resin layer, the ratio of the content of the filler (D) to the total content of all components except the solvent (ie, thermosetting The content of the filler (D) of the resin film is more preferably 5 to 45% by mass, still more preferably 5 to 40% by mass, particularly preferably 10 to 30% by mass. By setting the content of the filler (D) within such a range, the effect of suppressing the residue of the curable resin film on the upper portion of the bump is further enhanced, and the adjustment of the coefficient of thermal expansion becomes easier.

[Coupling agent (E)]

The resin layer forming composition (III) and the thermosetting resin film may contain a coupling agent (E). By using what has a functional group reactive with an inorganic compound or an organic compound as a coupling agent (E), the adhesiveness and adhesiveness of a thermosetting resin film to an adherend can be improved. In addition, by using the coupling agent (E), the water resistance of the first protective film obtained by curing the thermosetting resin film is improved without impairing heat resistance.

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

Examples of preferred silane coupling agents include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyl ether Oxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyl Oxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propylmethyl Diethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureapropyltriethoxysilane, 3-mercaptopropyltrimethoxy Silane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane Oxysilane, vinyltriacetoxysilane, imidazole silane, etc.

The coupling agent (E) contained in the resin layer forming composition (III) and the thermosetting resin film may be only one kind, or two or more kinds may be used. When there are two or more kinds, their combination and ratio can be selected arbitrarily.

When using the coupling agent (E), in the resin layer forming composition (III) and the thermosetting resin film, the coupling agent ( The content of E) is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, particularly preferably 0.1 to 5 parts by mass. By making the above-mentioned content of the coupling agent (E) more than the above-mentioned lower limit value, the improvement of the dispersibility of a filler (D) in a resin, and the adhesiveness of a thermosetting resin film and an adherend can be obtained more remarkably. The effect brought by the use of coupling agent (E) such as the improvement of Moreover, generation|occurrence|production of outgassing can be suppressed further by making the said content of a coupling agent (E) below the said upper limit.

[Crosslinking agent (F)]

When a polymer component (A) having functional groups such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups that can be bonded to other compounds is used, the composition for forming a resin layer (III) And the thermosetting resin film may contain a crosslinking agent (F). The crosslinking agent (F) is a component for bonding and crosslinking the functional group in the polymer component (A) with another compound, and by performing crosslinking in this way, the initial adhesive force of the thermosetting resin film can be adjusted and cohesion.

Examples of the crosslinking agent (F) include organic polyisocyanate compounds, organic polyimine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), aziridine crosslinking agents, etc. agent (crosslinking agent with aziridine group), etc.

Examples of the organic polyisocyanate compound include aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, and alicyclic polyisocyanate compounds (hereinafter, these compounds may be collectively abbreviated as "aromatic polyisocyanate compounds, etc."); Trimers, isocyanurate bodies, and adducts of the above-mentioned aromatic polyisocyanate compounds and the like; terminal isocyanate urethane prepolymers obtained by reacting the above-mentioned aromatic polyisocyanate compounds and the like with polyol compounds wait. The "adduct" refers to the aromatic polyisocyanate compound, aliphatic polyisocyanate compound or alicyclic polyisocyanate compound and ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil, etc. Reactants of low molecular weight active hydrogen compounds. As an example of the said adduct, the xylylene diisocyanate adduct of trimethylolpropane mentioned later etc. are mentioned. In addition, the "terminated isocyanate urethane prepolymer" is the same as that described above.

As the organic polyisocyanate compound, more specifically, for example, 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; 1,3-xylylene diisocyanate; 1,4-benzene Diphenylmethylene diisocyanate; Diphenylmethane-4,4'-diisocyanate; Diphenylmethane-2,4'-diisocyanate; 3-Methyldiphenylmethane diisocyanate; Hexamethylene diisocyanate ; Isophorone diisocyanate; Dicyclohexylmethane-4,4'-diisocyanate; Form any one or more compounds of toluene diisocyanate, hexamethylene diisocyanate and xylylene diisocyanate; lysine diisocyanate, etc.

Examples of the organic polyimine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridine carboxamide), trimethylolpropane-tri-β-nitrogen Pyridyl propionate, tetramethylolmethane-tris-β-aziridinyl propionate, N,N'-toluene-2,4-bis(1-aziridine carboxamide)triethylenemelamine wait.

When using an organic polyisocyanate compound as a crosslinking agent (F), it is preferable to use a hydroxyl group-containing polymer as a polymer component (A). When the crosslinking agent (F) has an isocyanate group and the polymer component (A) has a hydroxyl group, a crosslinked structure can be easily introduced into the thermosetting resin film by the reaction of the crosslinking agent (F) and the polymer component (A).

The crosslinking agent (F) contained in the resin layer forming composition (III) and the thermosetting resin film may be only one kind, or may be two or more kinds. When there are two or more kinds, their combination and ratio can be selected arbitrarily.

When using a crosslinking agent (F), the content of the crosslinking agent (F) in the resin layer forming composition (III) is preferably 0.01 to 20 parts by mass based on 100 parts by mass of the content of the polymer component (A), More preferably, it is 0.1-10 mass parts, Especially preferably, it is 0.5-5 mass parts. By making the said content of a crosslinking agent (F) more than the said lower limit, the effect by using a crosslinking agent (F) can be acquired more notably. Moreover, excessive use of a crosslinking agent (F) can be suppressed by making the said content of a crosslinking agent (F) below the said upper limit.

[other ingredients]

The composition (III) for forming a resin layer and the thermosetting resin film may contain, in addition to the above-mentioned polymer component (A), thermosetting component (B), curing accelerator (C), Components other than filler (D), coupling agent (E) and crosslinking agent (F).

As said other component, an energy ray curable resin, a photoinitiator, a general-purpose additive, etc. are mentioned, for example. The general-purpose additives are well-known additives, can be arbitrarily selected according to the purpose, and are not particularly limited, but examples of preferred additives include plasticizers, antistatic agents, antioxidants, colorants (dyes, pigments), and trapping agents. (gettering agent) and so on.

The other components contained in the resin layer forming composition (III) and the thermosetting resin film may be only one kind, or may be two or more kinds, and when there are two or more kinds, their combination and ratio can be selected arbitrarily.

The content of the composition (III) for resin layer formation and the said other component of a thermosetting resin film is not specifically limited, What is necessary is just to select suitably according to the objective.

[solvent]

It is preferable that the resin layer forming composition (III) further contains a solvent. The handling property of the composition (III) for resin layer formation containing a solvent becomes favorable.

The solvent is not particularly limited, but examples of preferred solvents include hydrocarbons such as toluene and xylene; methanol, ethanol, 2-propanol, isobutanol (2-methylpropan-1-ol), 1- Alcohols such as 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 contained in the composition (III) for resin layer formation may be only 1 type, and may be 2 or more types, and when it is 2 or more types, the combination and ratio of these can be arbitrarily selected.

It is preferable that the solvent contained in the composition (III) for resin layer formation is methyl ethyl ketone etc. from a point which can mix the component contained in the composition (III) for resin layer formation more uniformly.

The content of the solvent in the composition (III) for resin layer formation is not specifically limited, For example, what is necessary is just to select suitably according to the kind of components other than a solvent.

＜<Method for producing thermosetting resin film-forming composition>>

The thermosetting resin film forming composition, such as the resin layer forming composition (III), can be obtained by blending each component for constituting it.

The order of addition when blending each component is not specifically limited, Two or more components may be added simultaneously.

When a solvent is used, it may be used by mixing the solvent with any blended ingredients other than the solvent and diluting the blended ingredients beforehand, or may be used without diluting any blended ingredients other than the solvent in advance by blending the solvent with these The synthetic ingredients are mixed for use.

The method of mixing the components at the time of blending is not particularly limited, and may be appropriately selected from the following known methods: a method of mixing by rotating a stirrer or a stirring blade; a method of mixing by using a stirrer; and mixing by applying ultrasonic waves. method etc.

The temperature and time at the time of adding and mixing each component are not particularly limited as long as each blending component does not deteriorate, and may be appropriately adjusted, but the temperature is preferably 15 to 30°C.

○Energy ray curable resin film

The energy ray curable resin film contains an energy ray curable component (a).

In the energy ray-curable resin film, the energy ray-curable component (a) is preferably uncured and preferably has tackiness, and more preferably uncured and has tackiness.

The energy ray curable resin film may be only one layer (single layer), or may be multiple layers of two or more layers. When multiple layers are used, these multiple layers may be the same or different from each other. The combination of these multiple layers Not particularly limited.

The thickness of the energy ray curable resin film is preferably 1 to 100 μm, more preferably 5 to 75 μm, particularly preferably 5 to 50 μm. By making the thickness of an energy-beam curable resin film more than the said lower limit, the 1st protective film with higher protective ability can be formed. Moreover, it can suppress that thickness becomes excessive thickness by making the thickness of an energy-beam curable resin film below the said upper limit.

Here, the "thickness of the energy ray curable resin film" refers to the thickness of the entire energy ray curable resin film, for example, the thickness of the energy ray curable resin film composed of a plurality of layers refers to the thickness of the energy ray curable resin film. The total thickness of all the layers.

Curing when the first protective film is formed by attaching the energy ray-curable resin film to the bump formation surface of the semiconductor wafer and curing it, as long as the first protective film has a degree of curing sufficient to perform its function The conditions are not particularly limited, and may be appropriately selected according to the type of the thermosetting resin film.

For example, the irradiance of energy rays when curing the energy ray-curable resin film is preferably 180 to 280 mW/cm ² . In addition, the light quantity of the energy rays at the time of curing is preferably 450 to 1000 mJ/cm ² .

＜<Energy Beam Curable Resin Film Forming Composition＞＞

The energy ray curable resin film can be formed using the composition for energy ray curable resin film formation containing the constituent material. For example, an energy ray curable resin film can be formed on a target site by applying the composition for forming an energy ray curable resin film on a surface to be formed with an energy ray curable resin film and drying as necessary. The content ratio of the components which do not vaporize at normal temperature in the composition for energy ray-curable resin film formation is normally the same as the content ratio of the said components of an energy ray-curable resin film.

The coating of the composition for forming an energy ray-curable resin film may be performed by a known method, for example, an air knife coater, a blade coater, a bar coater, a gravure coater, and a roll coater may be used. , roller knife coater, curtain coater, die coater, knife coater, screen coater, Meyer rod coater, kiss coater and other coating machine methods.

The drying conditions of the energy ray-curable resin film-forming composition are not particularly limited, but when the energy-ray-curable resin film-forming composition contains a solvent described later, heat drying is preferred. It is preferable to dry the composition for energy ray-curable resin film formation containing a solvent, for example at 70-130 degreeC, and 10 second - 5 minute conditions.

<Resin layer forming composition (IV)>

Examples of the energy ray-curable resin film-forming composition include the energy ray-curable resin film-forming composition (IV) containing the energy ray-curable component (a) (in this specification, sometimes abbreviated as "resin layer-forming composition (IV)") and the like.

[Energy ray curable component (a)]

The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and is also a component for imparting film-forming properties, flexibility, and the like to the energy ray-curable resin film.

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

(Polymer (a1) having an energy ray curable group and having a weight average molecular weight of 80,000 to 2,000,000)

Examples of the polymer (a1) having an energy ray-curable group and having a weight-average molecular weight of 80,000 to 2,000,000 include acrylic resins obtained by polymerizing an acrylic polymer (a11) and an energy ray-curable compound (a12). (a1-1), the acrylic polymer (a11) has a functional group capable of reacting with a group of another compound, the energy ray-curable compound (a12) has a group reactive with the functional group, and An energy ray curable group such as an energy ray curable double bond.

Examples of functional groups capable of reacting with groups possessed by other compounds include hydroxyl, carboxyl, amino, and substituted amino groups (groups in which one or two hydrogen atoms of the amino group are replaced by groups other than hydrogen atoms) ), epoxy, etc. However, from the viewpoint of preventing corrosion of circuits such as semiconductor wafers or semiconductor chips, it is preferable that the functional group is a group other than a carboxyl group.

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

・Acrylic polymer with functional groups (a11)

Examples of the acrylic polymer (a11) having the functional group include polymers obtained by copolymerization of an acrylic monomer having the functional group and an acrylic monomer not having the functional group. A polymer in which a monomer other than an acrylic monomer (non-acrylic monomer) is further copolymerized in addition to the monomer.

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

As an acrylic monomer which has the said functional group, a hydroxyl group containing monomer, a carboxyl group containing monomer, an amino group containing monomer, a substituted amino group containing monomer, an epoxy group containing monomer etc. are mentioned, for example.

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

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; fumaric acid, itaconic acid, Ethylenically unsaturated dicarboxylic acids (dicarboxylic acids with ethylenically unsaturated bonds) such as toric acid and citraconic acid; anhydrides of said ethylenically unsaturated dicarboxylic acids; 2-carboxyethyl methacrylate, etc. (methacrylic acid) base) carboxyalkyl acrylate, etc.

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

The acrylic monomers having the functional groups constituting the acrylic polymer (a11) may be one type only, or two or more types may be used. When there are two or more types, their combination and ratio may be selected arbitrarily.

Examples of acrylic monomers that do not have the 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 ester, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, ( Isononyl methacrylate, Decyl (meth)acrylate, Undecyl (meth)acrylate, Lauryl (meth)acrylate (Lauryl (meth)acrylate), (Meth) ) tridecyl acrylate, myristyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate Constituting alkyl esters such as (palm (meth)acrylate), heptadecyl (meth)acrylate, stearyl (meth)acrylate (stearyl (meth)acrylate), etc. The alkyl group is an alkyl (meth)acrylate or the like having a chain structure having 1 to 18 carbon atoms.

Moreover, as an acrylic monomer which does not have the said functional group, the methoxymethyl (meth)acrylate, the methoxyethyl (meth)acrylate, the ethoxymethyl (meth)acrylate, etc. are mentioned, for example. Alkoxyalkyl-containing (meth)acrylates such as esters, ethoxyethyl (meth)acrylates, etc.; aromatic (meth)acrylic acid esters; non-crosslinking (meth)acrylamide and its derivatives; (meth)acrylic acid N,N-dimethylaminoethyl ester, (meth)acrylic acid N,N - Non-crosslinkable (meth)acrylates having a tertiary amino group such as dimethylaminopropyl ester, etc.

The acrylic monomers that do not have the functional groups constituting the acrylic polymer (a11) may be one type or two or more types. When there are two or more types, their combination and ratio can be selected arbitrarily.

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

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

In the acrylic polymer (a11), the ratio (content) of the amount of the structural unit derived from the acrylic monomer having the functional group to the total amount of the structural units constituting it is preferably 0.1 to 50 mass %, more preferably 1 to 40% by mass, particularly preferably 3 to 30% by mass. By setting the ratio in such a range, in the acrylic resin (a1-1) obtained by copolymerization of the acrylic polymer (a11) and the energy ray-curable compound (a12), energy The content of the radiation curable group can easily adjust the degree of curing of the first protective film to a preferred range.

The said acrylic polymer (a11) which comprises the said acrylic resin (a1-1) may be only 1 type, and may be 2 or more types, and when there are 2 or more types, their combination and ratio can be chosen arbitrarily.

In the composition (IV) for resin layer formation, content of an acrylic resin (a1-1) becomes like this. Preferably it is 1-40, More preferably, it is 2-30, Especially preferably, it is 3-20.

・Energy ray curable compound (a12)

The energy ray-curable compound (a12) preferably has one or more types selected from the group consisting of isocyanate group, epoxy group, and carboxyl group as functional groups that can interact with the acrylic polymer (a11). The reactive group more preferably has an isocyanate group as the group. For example, when the energy ray curable compound (a12) has an isocyanate group as the group, the isocyanate group easily reacts with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the functional group.

The energy ray curable compound (a12) preferably has 1 to 5 energy ray curable groups per 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, alkene Propyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate;

Acryloyl monoisocyanate compounds obtained by reacting diisocyanate compounds or polyisocyanate compounds with hydroxyethyl (meth)acrylate;

Acryloyl monoisocyanate compound obtained by reaction of diisocyanate compound or polyisocyanate compound, polyol compound, and hydroxyethyl (meth)acrylate, etc.

Among them, it is preferable that the energy ray curable compound (a12) is 2-methacryloyloxyethyl isocyanate.

The said energy ray curable compound (a12) which comprises the said acrylic resin (a1-1) may be only 1 type, and may be 2 or more types, and when there are 2 or more types, their combination and ratio can be chosen arbitrarily.

In the acrylic resin (a1-1), the content of the energy ray curable group derived from the energy ray curable compound (a12) relative to the content of the functional group derived from the acrylic polymer (a11) The ratio of the content is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, particularly preferably 50 to 100 mol%. By making the ratio of the said content into such a range, the adhesive force of a 1st protective film will become larger. In addition, when the energy ray curable compound (a12) is a monofunctional (having one of the above groups in one molecule) compound, the upper limit of the ratio of the content is 100 mol%, and when the energy ray curable compound (a12) is When the radiation curable compound (a12) is a polyfunctional (having 2 or more of said groups in 1 molecule) compound, the upper limit of the ratio of the said content may exceed 100 mol%.

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

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

When the polymer (a1) is at least partly cross-linked by a cross-linking agent, the polymer (a1) may not be a monomer that constitutes the acrylic polymer (a11). Any one of the above-mentioned monomers described above, and a monomer having a group reactive with a crosslinking agent is copolymerized and crosslinked at the group reactive with the crosslinking agent , may be a polymer obtained by crosslinking at a group derived from the energy ray curable compound (a12) that reacts with the functional group.

The polymer (a1) contained in the composition for forming a resin layer (IV) and the energy ray-curable resin film may be only one kind, or may be two or more kinds, and when there are two or more kinds, their combination and ratio You can choose arbitrarily.

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

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

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

Examples of the low-molecular-weight compound having an energy ray-curable group in the compound (a2) include polyfunctional monomers or oligomers, and acrylate compounds having a (meth)acryloyl group are preferred.

Examples of the acrylate compounds include 2-hydroxy-3-(meth)acryloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethylene Oxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di( Meth)acrylate, 2,2-bis[4-((meth)acryloxydiethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloyl Oxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloxypolypropoxy)phenyl]propane, tricyclodecane dimethanol di(meth)acrylate , 1,10-decanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di( Meth)acrylate, Tripropylene Glycol Di(meth)acrylate, Polypropylene Glycol Di(meth)acrylate, Polytetramethylene Glycol Di(meth)acrylate, Ethylene Glycol Di(meth)acrylate ester, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxyethoxy)phenyl] Difunctional ( Meth)acrylate;

Tris(2-(meth)acryloyloxyethyl)isocyanurate, ε-caprolactone modified tris-(2-(meth)acryloyloxyethyl)isocyanurate, ethoxy Glyceryl tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxy Polyfunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, dipentaerythritol hexa(meth)acrylate;

Polyfunctional (meth)acrylate oligomers such as urethane (meth)acrylate oligomers, etc.

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

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

The above-mentioned compound (a2) contained in the resin layer forming composition (IV) and the energy ray-curable resin film may be only one kind, or two or more kinds, and when there are two or more kinds, their combination and ratio may be Arbitrary choice.

[Polymer (b) having no energy ray curable group]

When the resin layer-forming composition (IV) and the energy ray-curable resin film contain the compound (a2) as the energy ray-curable component (a), it is preferable to further contain a polymer compound (a2) that does not have an energy ray-curable group. thing (b).

The polymer (b) may be at least partially crosslinked by a crosslinking agent, or may be uncrosslinked.

As a polymer (b) which does not have an energy-beam curable group, an acrylic polymer, a phenoxy resin, a urethane resin, a polyester, a rubber resin, an acrylic urethane resin, etc. are mentioned, for example.

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

The acrylic polymer (b-1) can be a known acrylic polymer, for example, it can be a homopolymer of one acrylic monomer, or it can be a copolymer of two or more acrylic monomers, or it can be A copolymer of one or two 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, glycidyl group-containing ( Meth)acrylates, hydroxyl-containing (meth)acrylates, substituted amino-containing (meth)acrylates, and the like. Here, the "substituted amino group" is the same as described above.

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 ester, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, ( Isononyl methacrylate, Decyl (meth)acrylate, Undecyl (meth)acrylate, Lauryl (meth)acrylate (Lauryl (meth)acrylate), (Meth) ) tridecyl acrylate, myristyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate Constituting alkyl esters such as (palm (meth)acrylate), heptadecyl (meth)acrylate, stearyl (meth)acrylate (stearyl (meth)acrylate), etc. The alkyl group is an alkyl (meth)acrylate or the like having a chain structure having 1 to 18 carbon atoms.

Examples of the (meth)acrylate having a cyclic skeleton include cycloalkyl (meth)acrylates such as isobornyl (meth)acrylate and dicyclopentyl (meth)acrylate;

Aralkyl (meth)acrylates such as benzyl (meth)acrylate;

Cycloalkenyl (meth)acrylate such as dicyclopentenyl (meth)acrylate;

Cycloalkenyloxyalkyl (meth)acrylate, such as dicyclopentenyloxyethyl (meth)acrylate, etc.

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

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

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

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

As the polymer (b) having no energy ray-curable group that is at least partly cross-linked by a cross-linking agent, for example, reactive functional groups in the polymer (b) react with a cross-linking agent. the obtained polymer.

The reactive functional group may be appropriately selected according to the type of crosslinking agent and the like, and is not particularly limited. For example, when the crosslinking agent is a polyisocyanate compound, the reactive functional group includes a hydroxyl group, a carboxyl group, an amino group, and the like, and among them, a hydroxyl group having high reactivity with an isocyanate group is preferable. Moreover, when a crosslinking agent is an epoxy compound, a carboxyl group, an amino group, an amide group etc. are mentioned as said reactive functional group, Among them, the carboxyl group with high reactivity with an epoxy group is preferable. However, from the viewpoint of preventing corrosion of circuits of semiconductor wafers or semiconductor chips, it is preferable that the reactive functional group is a group other than a carboxyl group.

As a polymer (b) which has the said reactive functional group and does not have an energy-beam curable group, the polymer obtained by polymerizing the monomer which has the said reactive functional group at least is mentioned, for example. In the case of the acrylic polymer (b-1), the above acrylic monomers and non- Any one or two of the acrylic monomers will suffice. Examples of the polymer (b) having a hydroxyl group as a reactive functional group include polymers obtained by polymerizing a hydroxyl group-containing (meth)acrylate, and in addition, the above-mentioned A polymer obtained by polymerizing monomers in which one or more hydrogen atoms in the acrylic monomer or non-acrylic monomer are substituted with the reactive functional groups.

In the polymer (b) having a reactive functional group, the ratio (content) of the amount of structural units derived from monomers having a reactive functional group to the total amount of structural units constituting it is preferably 1 to 20 mass %, more preferably 2 to 10% by mass. By making the said ratio into such a range, in the said polymer (b), the degree of crosslinking becomes a more preferable range.

The weight average molecular weight (Mw) of the polymer (b) not having an energy ray curable group is preferably 10,000 to 2,000,000, more preferably 100000～1500000. Here, the "weight average molecular weight" is the same as described above.

The polymer (b) not having an energy ray curable group contained in the resin layer forming composition (IV) and the energy ray curable resin film may be only one kind, or may be two or more kinds, and may be two kinds In the above cases, combinations and ratios of these can be selected arbitrarily.

As the composition (IV) for resin layer formation, the composition for resin layer formation containing either one or both of the said polymer (a1) and the said compound (a2) is mentioned. Furthermore, when the resin layer forming composition (IV) contains the compound (a2), it is preferable that it further contains a polymer (b) not having an energy ray curable group. In this case, it is also preferable that it further contains the compound (a2). (a1). Moreover, the composition (IV) for resin layer formation may contain the said polymer (a1) and the polymer (b) which does not have an energy-ray curable group together, without containing the said compound (a2).

When the composition (IV) for forming a resin layer contains the polymer (a1), the compound (a2) and the polymer (b) not having an energy ray curable group, the composition (IV) for forming a resin layer ), the content of the compound (a2) is preferably 10 to 400 parts by mass relative to 100 parts by mass of the total content of the polymer (a1) and the polymer (b) not having an energy-ray-curable group, More preferably, it is 30-350 mass parts.

In the resin layer-forming composition (IV), the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group relative to the total content of components other than the solvent The ratio of the total content (that is, the total content of the energy ray curable component (a) and the polymer (b) having no energy ray curable group) of the energy ray curable resin film is preferably 5 to 90% by mass , more preferably 10 to 80% by mass, particularly preferably 20 to 70% by mass. By making the said ratio of content of an energy ray curable component into such a range, the energy ray curability of an energy ray curable resin film becomes more favorable.

In addition to the above-mentioned energy ray curable components, the composition for forming a resin layer (IV) may contain, according to the purpose, a compound selected from a thermosetting component, a photopolymerization initiator, a filler, a coupling agent, a crosslinking agent, and a general-purpose additive. One or more of the group. For example, by using the resin layer-forming composition (IV) containing the energy ray-curable component and the thermosetting component, the adhesive force of the formed energy ray-curable resin film to the adherend is improved by heating. The strength of the first protective film formed of the energy ray curable resin film is also improved.

Examples of the thermosetting component, photopolymerization initiator, filler, coupling agent, crosslinking agent, and general-purpose additives in the resin layer-forming composition (IV) include the resin layer-forming composition (III) The thermosetting component (B), the photopolymerization initiator, the filler (D), the coupling agent (E), the crosslinking agent (F) and the general additives are the same.

In the resin layer forming composition (IV), each of the thermosetting component, photopolymerization initiator, filler, coupling agent, crosslinking agent and general additive may be used alone or in combination of two or more, When using two or more kinds at the same time, their combination and ratio can be selected arbitrarily.

The content of the thermosetting component, photopolymerization initiator, filler, coupling agent, crosslinking agent, and general additives in the composition (IV) for forming a resin layer may be appropriately adjusted according to the purpose and is not particularly limited.

Since the handleability of the composition (IV) for resin layer formation improves by dilution, it is preferable to further contain a solvent.

As a solvent contained in the composition (IV) for resin layer formation, the thing similar to the solvent in the composition (III) for resin layer formation is mentioned, for example.

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

＜<Manufacturing method of energy ray-curable resin film-forming composition>>

Compositions for energy ray-curable resin film formation, such as the composition for resin layer formation (IV), can be obtained by blending each component for constituting it.

The order of addition when blending each component is not specifically limited, Two or more components may be added simultaneously.

When a solvent is used, it may be used by mixing the solvent with any blended ingredients other than the solvent and diluting the blended ingredients beforehand, or may be used without diluting any blended ingredients other than the solvent in advance by blending the solvent with these The synthetic ingredients are mixed for use.

The method of mixing the components at the time of blending is not particularly limited, and may be appropriately selected from the following known methods: a method of mixing by rotating a stirrer or a stirring blade; a method of mixing by using a stirrer; and mixing by applying ultrasonic waves. method etc.

The temperature and time at the time of adding and mixing each component are not particularly limited as long as each blending component does not deteriorate, and may be appropriately adjusted, but the temperature is preferably 15 to 30°C.

◎Adhesive layer

The adhesive layer improves the adhesiveness between the first base material and the cushion layer, and highly suppresses peeling of the first base material and the cushion layer in the first sheet for forming a protective film. Therefore, when using the 1st sheet|seat for protective film formation provided with an adhesive layer, the laminated structure of a 1st base material, an adhesive layer, and a buffer layer can be maintained more stably.

The adhesive layer is sheet or film.

As a preferable adhesive layer, the adhesive layer containing ethylene-vinyl acetate copolymer resin (EVA) etc. is mentioned, for example.

The adhesive layer may be only one layer (single layer), or may be multiple layers of two or more layers. When multiple layers are used, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited. .

The thickness of the adhesive layer is preferably 10 to 100 μm, more preferably 25 to 85 μm, particularly preferably 40 to 70 μm.

Here, the "thickness of the adhesive layer" refers to the thickness of the entire adhesive layer, for example, the thickness of the adhesive layer composed of a plurality of layers refers to the total thickness of all the layers constituting the adhesive layer.

＜＜Adhesive layer forming composition＞＞

The adhesive layer can be formed using the composition for adhesive layer formation containing the constituent material. For example, an adhesive layer can be formed at a target site by extrusion-molding the composition for forming an adhesive layer on a surface to be formed of an adhesive layer. A more specific method of forming the adhesive layer will be described in detail later together with methods of forming other layers. The content ratio of the components which do not vaporize at normal temperature in the composition for forming an adhesion layer is usually the same as the content ratio of the above-mentioned components of the adhesion layer.

<Adhesive layer forming composition (VI)>

As a composition for adhesive layer formation, the composition (VI) etc. for adhesive layer formation containing ethylene-vinyl acetate copolymer resin (EVA) are mentioned, for example.

The density of the ethylene-vinyl acetate copolymer resin is preferably 1100 kg/m ³ or less, more preferably 850-1100 kg/m ³ , particularly preferably 900-1000 kg/m ³ . In addition, in this specification, unless otherwise stated, "the density of an ethylene-vinyl acetate copolymer resin" means the value measured based on JISK7112:1999.

The melting point of the ethylene-vinyl acetate copolymer resin is preferably 50 to 95°C, more preferably 65 to 85°C.

The melt flow rate (MFR) at 190° C. of the ethylene-vinyl acetate copolymer resin is preferably 1 to 10 g/10 minutes, more preferably 3 to 8 g/10 minutes.

In addition, in this specification, "the melt flow rate of an ethylene-vinyl acetate copolymer resin" means the value measured based on JISK7210:1999 unless otherwise stated.

It is preferable that content of the ethylene-vinyl acetate copolymer resin of the adhesive layer forming composition (VI) and an adhesive layer is 80-100 mass %.

[other ingredients]

The composition for forming an adhesion layer (VI) and the adhesion layer may contain other components than the ethylene-vinyl acetate copolymer resin within the range that does not impair the effect of the present invention.

These other components are not particularly limited and may be appropriately selected according to purposes.

The composition (VI) for forming an adhesion layer and the said other components contained in an adhesion layer may be only 1 type, and may be 2 or more types, and when it is 2 or more types, the combination and ratio of these can be arbitrarily selected.

The content of the composition (VI) for forming an adhesion layer and the said other component of an adhesion layer is not specifically limited, What is necessary is just to select suitably according to the objective.

◇Manufacturing method of the first protective film forming sheet

The first sheet for forming a protective film can be produced by sequentially laminating the above-mentioned layers so that the above-mentioned layers are in a corresponding positional relationship. The method of forming each layer is the same as described above.

For example, a first protective film-forming sheet in which a first base material, a buffer layer, and a curable resin film are sequentially laminated in the thickness direction thereof can be produced by the method shown below. That is, the buffer layer is laminated on the first base material by extrusion molding the buffer layer-forming composition on the first base material. In addition, the curable resin film-forming composition described above is applied on the release-treated surface of the release film, and dried as necessary to laminate the curable resin film. And, by laminating the curable resin film on the peeling film and the buffer layer on the first base material, the first protective layer formed by sequentially laminating the buffer layer, the curable resin film, and the release film on the first base material is obtained. Sheet for film formation. What is necessary is just to remove a peeling film when using the sheet|seat for 1st protective film formation.

In the above-mentioned manufacturing method, any one or both of the formation step and the lamination step of the other layer are appropriately added in such a manner that the lamination position of the other layer is at an appropriate position, it is possible to manufacture a The sheet|seat for 1st protective film formation of layers other than each layer.

For example, the first protective film-forming sheet in which the first base material, the adhesive layer, the buffer layer, and the curable resin film are sequentially laminated in the thickness direction can be produced by the method shown below. That is, by co-extruding the composition for forming an adhesion layer and the composition for forming a buffer layer on a 1st base material, an adhesion layer and a buffer layer are sequentially laminated|stacked on a 1st base material. Furthermore, the curable resin film was laminated|stacked on the peeling film separately using the method similar to the above. Next, the curable resin film on the peeling film is bonded to the buffer layer on the first substrate and the adhesive layer, thereby obtaining an adhesive layer, a buffer layer, and a curable resin film sequentially laminated on the first substrate. And the sheet|seat for 1st protective film formation which peeled a film. What is necessary is just to remove the peeling film on a curable resin film when using the sheet|seat for 1st protective film formation.

◇How to use the first protective film forming sheet

The sheet|seat for 1st protective film formation of this invention can be used as follows, for example.

That is, first, the first protective film forming sheet is bonded to the bump forming surface of the semiconductor wafer via the curable resin film. At this time, by bonding the curable resin film while heating, the curable resin film is softened, and the curable resin film is closely bonded to the bump formation surface.

Next, if necessary, after grinding the surface (i.e., the back surface) of the semiconductor wafer opposite to the bump formation surface, a sheet for forming a protective film (described in this specification) for protecting the back surface is attached to the back surface. , referred to as "the sheet for forming a second protective film"). As the second protective film forming sheet, for example, a second protective film forming sheet having a second protective film forming film that can be formed to protect semiconductor wafers and semiconductors by curing the second protective film forming film can be used. A second protective film on the back of the chip. The sheet for forming a second protective film may be a sheet for forming formed by including a dicing sheet in addition to the second protective film forming film.

Next, only the curable resin film in the first sheet for forming a protective film bonded to the bump forming surface of the semiconductor wafer remains on the bump forming surface, and the other layers are peeled off from the curable resin film. Here, for example, in the case of the first protective film forming sheet 1 shown in FIG. When forming the sheet 2 , "other layers to be peeled" refers to the first base material 11 , the adhesive layer 14 , and the buffer layer 13 .

Next, by curing the curable resin film, a first protective film is formed on the bump formation surface of the semiconductor wafer.

Thereafter, it is possible to proceed up to the manufacture of the semiconductor device by the same method as the conventional method. That is, the semiconductor wafer in the state provided with the first protective film is diced to form semiconductor chips, and the semiconductor chip in the state provided with the first protective film is picked up. The second protective film forming film may be cured at an appropriate timing according to its type to form a second protective film. The picked up semiconductor chip is flip-chip mounted on a wiring board to finally constitute a semiconductor device.

By using the first sheet for forming a protective film of the present invention, at least the upper portion of the bump penetrates the curable resin film and protrudes at the stage of attaching the sheet to the bump formation surface of the semiconductor wafer, and the upper portion of the bump is suppressed Residue of curable resin film. As a result, at least the upper portion of the bump penetrates the first protective film and protrudes. When a semiconductor chip including such a first protective film and bumps is flip-chip mounted on a wiring board, the electrical connection between the semiconductor chip and the wiring board becomes favorable.

Hereinafter, the process from bonding the first protective film forming sheet of the present invention to the bump formation surface of the semiconductor wafer to forming the first protective film will be described in more detail with reference to the drawings.

FIG. 3 is a cross-sectional view schematically showing an example of a method of using the first protective film forming sheet 1 shown in FIG. 1 .

When using the sheet 1 for forming the first protective film, first, as shown in (a) of FIG. The first sheet 1 for forming a protective film was arranged in such a manner.

The height of the bump 91 is not particularly limited, but is preferably 120 to 300 μm, more preferably 150 to 270 μm, particularly preferably 180 to 240 μm. The function of the bump 91 can be further improved by making the height of the bump 91 more than the said lower limit. Moreover, the effect of suppressing the curable resin film 12 remaining on the upper part of the bump 91 is further enhanced by making the height of the bump 91 below the said upper limit.

In addition, in this specification, "the height of a bump" means the height from a bump formation surface to the part which exists in the highest position among a bump.

The width of the bump 91 is not particularly limited, but is preferably 170 to 350 μm, more preferably 200 to 320 μm, particularly preferably 230 to 290 μm. The function of the bump 91 can be further improved by making the width|variety of the bump 91 more than the said lower limit. Moreover, the effect of suppressing the curable resin film 12 remaining on the upper part of the bump 91 is further enhanced by making the height of the bump 91 below the said upper limit.

In addition, in this specification, the "bump width" refers to a line segment obtained by connecting two different points on the surface of the bump with a straight line when the bump is viewed from above in a direction perpendicular to the bump forming surface. the maximum value.

The distance between adjacent bumps 91 is not particularly limited, but is preferably 250-800 μm, more preferably 300-600 μm, particularly preferably 350-500 μm. By making the distance equal to or greater than the lower limit, the function of the bump 91 can be further improved. Moreover, the effect of suppressing the curable resin film 12 remaining on the upper part of the bump 91 is further enhanced by making the said distance below the said upper limit.

In addition, in this specification, "the distance between adjacent bumps" means the minimum value of the distance between the surfaces of adjacent bumps.

Next, the curable resin film 12 is brought into contact with the bumps 91 on the semiconductor wafer 9 , and the first protective film forming sheet 1 is pressed against the semiconductor wafer 9 . Thereby, the first surface 12 a of the curable resin film 12 is sequentially pressure-bonded to the surface 91 a of the bump 91 and the bump formation surface 9 a of the semiconductor wafer 9 . At this time, by heating the curable resin film 12, the curable resin film 12 softens, spreads between the bumps 91 to cover the bumps 91, closely adheres to the bump forming surface 9a, and simultaneously covers the bumps 91. The surface 91a of the surface 91a, especially the surface 91a of the vicinity of the bump forming surface 9a, is filled with the bump 91.

In this manner, as shown in FIG. 3( b ), the curable resin film 12 of the first protective film forming sheet 1 is bonded to the bump forming surface 9 a of the semiconductor wafer 9 .

As a method of crimping the first protective film forming sheet 1 on the semiconductor wafer 9 as described above, known methods of crimping and sticking various sheets to the object can be applied, for example, using a layer A method of a laminate roller, etc.

The heating temperature of the first protective film forming sheet 1 when pressure-bonded to the semiconductor wafer 9 may be a temperature at which the curable resin film 12 does not cure at all or a temperature at which the curable resin film 12 does not cure excessively, and is preferably 80 to 80 ℃. 100°C, more preferably 85 to 95°C.

The pressure when the first protective film forming sheet 1 is pressure-bonded to the semiconductor wafer 9 is not particularly limited, but is preferably 0.1 to 1.5 MPa, more preferably 0.3 to 1 MPa.

When the first protective film forming sheet 1 is pressure-bonded to the semiconductor wafer 9 as described above, the pressure from the bumps 91 is applied to the curable resin film 12 and buffer layer 13 in the first protective film forming sheet 1 . In the initial stage, the first surface 12a of the curable resin film 12 and the first surface 13a of the buffer layer 13 are deformed into concave shapes. And, cracks occur in the curable resin film 12 to which the pressure from the bump 91 is always applied. Finally, when first surface 12 a of curable resin film 12 is pressure-bonded to bump formation surface 9 a of semiconductor wafer 9 , upper portion 910 of bump 91 penetrates curable resin film 12 and protrudes. In addition, at this final stage, generally, the upper portion 910 of the bump 91 does not penetrate the buffer layer 13 . This is because the buffer layer 13 has a buffering effect on the pressure applied by the bump 91 .

As shown in FIG. 3( b ), at the stage of attaching the first protective film forming sheet 1 to the bump forming surface 9 a of the semiconductor wafer 9 , there is no or almost no curability remaining on the upper portion 910 of the bump 91 . Resin film 12. In addition, in this specification, unless otherwise specified, "the curable resin film hardly remains on the upper part of the bump" means that the curable resin film slightly remains on the upper part of the bump, but the remaining amount is the When the semiconductor chip of the bump is flip-chip mounted on the wiring board, the electrical connection between the semiconductor chip and the wiring board is not hindered.

As described above, the reason why the curable resin film 12 can be suppressed from remaining on the upper portion 910 of the bump 91 is that, as described above, when the curable resin film 12 is deformed by applying pressure from the bump 91 , the curable resin film 12 will be deformed. The resin film 12 is designed to be particularly easy to break. That is, in the first sheet 1 for forming a protective film, by making the curable resin film 12 and the buffer layer 13 satisfy the relationship of the above-mentioned formula (w1), these (the curable resin film 12 and the buffer layer 13) generate a large When strained, the buffer layer 13 exhibits an appropriate buffer function, and the curable resin film 12 is broken in an appropriate state.

After attaching the first protective film forming sheet 1 to the bump forming surface 9a of the semiconductor wafer 9, further, if necessary, apply the sheet 1 to the surface (back surface) 9b of the semiconductor wafer 9 opposite to the bump forming surface 9a. After grinding, the sheet|seat (illustration omitted) for 2nd protective film formation is affixed to this back surface 9b.

Next, as shown in FIG. 3( c ), the first base material 11 and the buffer layer 13 are peeled off from the curable resin film 12 .

Next, by curing the curable resin film 12, a first protective film 12' is formed on the bump forming surface 9a as shown in FIG. 3(d).

In addition, here, the case where the sheet 1 for forming a first protective film shown in FIG. 1 is used has been described, and the sheet 2 for forming a first protective film shown in FIG. When using a sheet, this first sheet for forming a protective film exhibits the same effect as when using the sheet 1 for forming a first protective film.

FIG. 4 is a cross-sectional view schematically showing an example of a method of using the first protective film forming sheet 2 shown in FIG. 2 .

When using the sheet 2 for forming a first protective film, first, as shown in (a) of FIG. The sheet|seat 2 for 1st protective film formation is arrange|positioned so that 9a may oppose.

Next, the curable resin film 12 is brought into contact with the bumps 91 on the semiconductor wafer 9 while being heated, and the first protective film forming sheet 2 is pressed against the semiconductor wafer 9 . Thereby, the first surface 12 a of the curable resin film 12 is sequentially pressure-bonded to the surface 91 a of the bump 91 and the bump formation surface 9 a of the semiconductor wafer 9 . As shown in FIG. 4( b ), curable resin film 12 of first protective film forming sheet 2 is bonded to bump forming surface 9 a of semiconductor wafer 9 as described above.

At this time, the first protective film forming sheet 2 can be pressure-bonded to the semiconductor wafer 9 by the same method as when the first protective film forming sheet 1 is used.

When the first protective film forming sheet 2 is pressure-bonded to the semiconductor wafer 9 as described above, the pressure from the bumps 91 is applied to the curable resin film 12 and buffer layer 13 in the first protective film forming sheet 2 . In the initial stage, the first surface 12a of the curable resin film 12 and the first surface 13a of the buffer layer 13 are deformed into concave shapes. And, cracks occur in the curable resin film 12 to which the pressure from the bump 91 is always applied. Finally, when first surface 12 a of curable resin film 12 is pressure-bonded to bump formation surface 9 a of semiconductor wafer 9 , upper portion 910 of bump 91 penetrates curable resin film 12 and protrudes. In this final stage, typically, the upper portion 910 of the bump 91 does not penetrate the buffer layer 13 .

In addition, by using the first protective film forming sheet 2, as described above, in the process of bonding the curable resin film 12 to the bump formation surface 9a of the semiconductor wafer 9, the adhesive layer 14 highly suppresses the first protective film formation. The peeling of the base material 11 and the buffer layer 13 more stably maintains the laminated structure of the first base material 11 , the adhesive layer 14 and the buffer layer 13 .

As shown in FIG. 4( b ), at the stage of attaching the first protective film forming sheet 2 to the bump forming surface 9 a of the semiconductor wafer 9 , the same process as that of the first protective film forming sheet 1 is performed. As a result, no or almost no curable resin film 12 remains on the upper portion 910 of the bump 91 .

After attaching the first protective film forming sheet 2 to the bump forming surface 9a of the semiconductor wafer 9, further, if necessary, apply a protective film to the surface (back surface) 9b of the semiconductor wafer 9 opposite to the bump forming surface 9a. After grinding, the sheet|seat (illustration omitted) for 2nd protective film formation is affixed to this back surface 9b.

Next, as shown in FIG. 4( c ), the first base material 11 , the adhesive layer 14 , and the buffer layer 13 are peeled off from the curable resin film 12 .

Next, by curing the curable resin film 12, a first protective film 12' is formed on the bump forming surface 9a as shown in FIG. 4(d).

For example, by obtaining SEM imaging data of the bump, it can be confirmed whether or not a curable resin film or a protective film remains on the upper portion of the bump.

Example

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

The components used for preparation of the composition for thermosetting resin film formation are shown below.

· Polymer composition

Polymer component (A)-1: polyvinyl butyral (manufactured by SEKISUICHEMICAL Co., Ltd.) having structural units represented by the following formulas (i)-1, (i)-2, and (i)-3 "S-LEC BL-10", weight average molecular weight 25000, glass transition temperature 59℃)

Polymer component (A)-2: butyl acrylate (hereinafter, abbreviated as "BA") (55 parts by mass), methyl acrylate (hereinafter, abbreviated as "MA") (10 parts by mass), glycidyl methacrylate Acrylic resin (weight average molecular weight 800000, glass transition temperature -28°C).

[chemical formula 1]

In the formula, l ₁ is about 28, m ₁ is 1-3, and n ₁ is an integer of 68-74.

·Epoxy resin

Epoxy resin (B1)-1: Liquid bisphenol F type epoxy resin ("YL983U" manufactured by Mitsubishi Chemical Corporation)

Epoxy resin (B1)-2: polyfunctional aromatic epoxy resin ("EPPN-502H" manufactured by Nippon Kayaku Co., Ltd.)

Epoxy resin (B1)-3: Dicyclopentadiene type epoxy resin ("EPICLON HP-7200" manufactured by DIC CORPORATION)

·Thermal curing agent

Thermosetting agent (B2)-1: Novolak type phenolic resin (manufactured by SHOWA DENKO K.K. "BRG-556")

·Curing Accelerator

Curing accelerator (C)-1: 2-phenyl-4,5-dihydroxymethylimidazole ("CUREZOL 2PHZ-PW" manufactured by SHIKOKU CHEMICALSCORPORATION)

·Filler

Filler (D)-1: Epoxy-modified spherical silica (“ADMANANOYA050C-MKK” manufactured by Admatechs Corporation)

[Example 1]

<Manufacture of the first protective film forming sheet>

(Preparation of thermosetting resin film-forming composition)

To make polymer component (A)-1, epoxy resin (B1)-1, epoxy resin (B1)-2, epoxy resin (B1)-3, thermosetting agent (B2)-1 and curing accelerator (C)-1 is dissolved or dispersed in methyl ethyl ketone so that the ratio of the content of (C)-1 becomes the value shown in Table 1, and stirred at 23°C to obtain a composition for forming a thermosetting resin film. The resin layer forming composition (III) whose solid content concentration is 55 mass %. In addition, the description of "-" in the column of the component contained in Table 1 shows that the composition for thermosetting resin film formation does not contain this component.

(Manufacture of the first protective film forming sheet)

The density 950kg/m ³ , melting point less than 72°C, melt flow rate (190°C) 6g/10 minutes), ethylene-α-olefin copolymer (manufactured by Mitsui Chemicals "TAFMER DF640", density 864kg/m ³ , melting point less than 50 ℃, melt flow rate (190°C) 3.6g/10 minutes, melt flow rate (230°C) 6.7g/10 minutes) co-extruded into polyethylene terephthalate (PET) film ( "lumirror (registered trademark)" manufactured by TORAY INDUSTRIES, INC., thickness 100 μm), so that the adhesive layer composed of ethylene-vinyl acetate copolymer resin and the buffer layer composed of ethylene-α-olefin copolymer (thickness 400 μm) It was laminated on the first base material composed of the above-mentioned PET film.

In addition, the composition for forming a thermosetting resin film obtained above was coated on a release film (manufactured by Lintec Corporation. -PET381031", thickness 38 μm) on the peeling treated surface, and heat and dry at 120° C. for 2 minutes to form a thermosetting resin film with a thickness of 30 μm.

Next, the thermosetting resin film on the release film is bonded to the buffer layer formed on the first base material to obtain an adhesive layer, a buffer layer, a thermosetting resin film, and a release film that are sequentially laminated on the first base material. The first sheet for forming a protective film having the configuration shown in FIG. 2 .

<Evaluation of the first protective film forming sheet>

(Measurement of shear elastic modulus G' of buffer layer and thermosetting resin film)

A buffer layer having a thickness of 1000 μm was formed by the same method as above except that the coating amount of the buffer layer forming composition was changed. Next, this buffer layer was cut into a disc shape with a diameter of 8 mm to obtain a test piece of the buffer layer.

A thermosetting resin film having a thickness of 1000 μm was formed by the same method as above except for changing the coating amount of the composition for forming a thermosetting resin film. Next, this thermosetting resin film was cut into a disc shape with a diameter of 8 mm to obtain a test piece of the thermosetting resin film.

The installation position of the test piece of the shear viscosity measuring device is kept warm at 90°C in advance, the test piece of the buffer layer and the thermosetting resin film obtained above is placed on the installation position, and the measurement jig is pressed against the upper surface of the test piece, Thereby, the test piece is fixed and installed in the said installation position.

Next, under the conditions of a temperature of 90°C and a measurement frequency of 1 Hz, the generated strain was gradually increased to 0.01% to 1000%, and the shear modulus G' of the test piece was measured when the strain was applied. The results are shown in Figure 5. In FIG. 5, the measured value shown as "Example 1" is the measured value of the test piece of a thermosetting resin film.

(Confirmation of whether there is a thermosetting resin film remaining on the upper part of the bump)

The thermosetting resin film of the first protective film forming sheet obtained above was brought into contact with the bumps of the semiconductor wafer, and the first protective film forming sheet was pressure-bonded to the semiconductor wafer while heating. As the semiconductor wafer, a semiconductor wafer having a bump height of 210 μm, a bump width of 250 μm, and a distance between bumps of 400 μm was used. Moreover, the heating temperature of the sheet|seat for 1st protective film formation was 90 degreeC, and the pressure was 0.5 MPa. In this way, the thermosetting resin film is bonded to the bump formation surface of the semiconductor wafer.

Next, the first substrate, the adhesive layer and the buffer layer are peeled off from the thermosetting resin film to expose the thermosetting resin film.

Next, using a scanning electron microscope (SEM, "VE-9700" manufactured by KEYENCE CORPORATION.), the bumps on the semiconductor wafer were observed from a direction at an angle of 60° to the direction perpendicular to the bump formation surface of the semiconductor wafer. On the surface, check whether there is any residue of the thermosetting resin film on the upper part of the bump. The results are shown in Table 1.

[Examples 2-3, Comparative Examples 1-2]

<Manufacturing and evaluation of the first protective film forming sheet>

When preparing a composition for forming a thermosetting resin film, except that one or both of the types and content ratios of the components are set as shown in Table 1, and the shear elastic modulus of the test piece of the buffer layer is not adjusted Except for measuring the quantity G', the 1st sheet|seat for protective film formation was manufactured and evaluated by the method similar to Example 1. The results are shown in FIG. 5 and Table 1. In FIG. 5, the measured values shown as "Example 2", "Example 3", "Comparative Example 1", and "Comparative Example 2" are the measurements of the test pieces of the thermosetting resin films in these Examples and Comparative Examples, respectively. value.

[Table 1]

As is clear from FIG. 5 , in Examples 1 to 3, the buffer layer and the thermosetting resin film satisfy the relationship of formula (w1). In Examples 1 and 2, although Gc300' could not be directly measured, the relationship of Gb300'>Gc300' was satisfied.

Furthermore, in Examples 1 and 2, although Gc200' and Gc400' cannot be directly measured, it is also obvious that the relationship of Gb200'>Gc200' and Gb400'>Gc400' is satisfied, and the formulas (w2) and (w3) are also satisfied. Relationship. On the other hand, in Example 3, although the relationship of the expression (w2) is satisfied, the relationship of the expression (w3) is not satisfied.

In addition, as is clear from FIG. 5, in Examples 1 to 3, in the function (function Fb) of the strain of the buffer layer and the shear modulus G' (Gb'), there is a difference in the shear modulus Gb'. A constant region (fluctuating region Rb), and the shear modulus Gb′ of the buffer layer at a strain of 300% is included in the region (fluctuating region Rb).

Furthermore, in Examples 1 to 3, in the function (function Fc) of the strain of the thermosetting resin film and the shear elastic modulus G' (Gc'), there is a region where the shear elastic modulus Gc' is not constant (maybe variable region Rc). In addition, in Examples 1 and 2, although the strain such as 300% of the thermosetting resin film was not directly observed, in Example 3, the shear elastic modulus Gc' when the strain of the thermosetting resin film is 300% is included in In the above region (variation region Rc).

In addition, when the first protective film-forming sheets of Examples 1 to 3 were used, it was confirmed from the imaging data of the SEM that no thermosetting resin film remained on the bump upper portion of the semiconductor wafer.

On the other hand, as is clear from FIG. 5 , in Comparative Examples 1 and 2, the buffer layer and the thermosetting resin film did not satisfy the relationship of the formula (w1). In Comparative Examples 1 and 2, although the relation of the formula (w2) was satisfied, the relation of the formula (w3) was not satisfied.

In addition, when the first protective film-forming sheets of Comparative Examples 1 and 2 were used, it was confirmed that the thermosetting resin film remained on the bump upper portion of the semiconductor wafer. In the SEM imaging data of these comparative examples, there is a stripe-like pattern in the entire area including the upper surface of the bump, and furthermore, it is clearly confirmed that the size of the bump is significantly larger than that of the examples in terms of appearance. Until the thermosetting resin film remains on the surface of the bump. The thickness of the thermosetting resin film remaining on the bump was calculated from the imaging data of the SEM. As a result, Comparative Example 1 was about 9.4 μm, and Comparative Example 2 was about 4.8 μm.

Industrial Applicability

The present invention is applicable to the manufacture of a semiconductor chip or the like having bumps on the connection pads used in the flip-chip mounting method.

Explanation of reference signs

1, 2: first protective film forming sheet, 11: first base material, 11a: first surface of first base material, 12: curable resin film, 12a: first surface of curable resin film, 12' : first protective film, 13: buffer layer, 13a: first surface of buffer layer, 14: adhesive layer, 14a: first surface of adhesive layer, 9: semiconductor wafer, 9a: bump of semiconductor wafer Forming surface, 91: bump, 91a: surface of bump, 910: upper part of bump.

Claims (6)

1. A sheet for forming a first protective film comprising a first base material, a buffer layer formed on the first base material, and a curable resin film formed on the buffer layer, forming a first protective film on the surface of the semiconductor wafer by attaching the curable resin film to the surface having the bump and curing it, Under the conditions of temperature 90°C and frequency 1 Hz, the test piece of the buffer layer with a diameter of 8 mm and a thickness of 1 mm is strained, and the strain distribution measurement of the shear elastic modulus G' of the test piece of the buffer layer is measured. , the shear elastic modulus of the test piece of the buffer layer when the strain of the test piece of the buffer layer is 300% is Gb300', Under the conditions of a temperature of 90°C and a frequency of 1 Hz, the test piece of the curable resin film with a diameter of 8 mm and a thickness of 1 mm is strained, and the shear modulus G' of the test piece of the curable resin film is measured. During the strain distribution measurement, the shear elastic modulus of the test piece of the curable resin film when the strain of the test piece of the curable resin film is 300% is Gc300′, The Gb300' and the Gc300' satisfy the following relationship, Formula (w1): Gb300'≥Gc300'. 2. The sheet for forming a first protective film according to claim 1, wherein the shear modulus Gb200' of the test piece for the cushion layer when the strain of the test piece for the cushion layer is 200% is the same as the The shear elastic modulus Gc200' of the test piece of the curable resin film when the strain of the test piece of the curable resin film is 200% satisfies the following relationship, Formula (w2): Gb200'≥Gc200'. 3. The first sheet for forming a protective film according to claim 1 or 2, wherein the shear elastic modulus Gb of the test piece of the cushion layer when the strain of the test piece of the cushion layer is 400% is 400′ The shear elastic modulus Gc400' of the test piece of the curable resin film when the strain of the test piece of the curable resin film is 400% satisfies the following relationship, Formula (w3): Gb400'≥Gc400'. 4. The sheet for forming a first protective film according to claim 1 or 2, wherein the strain of the test piece of the cushion layer obtained by the strain distribution measurement and the shear of the test piece of the cushion layer In the function of the elastic modulus Gb', there is a region where the shear modulus of elasticity Gb' is not constant, and the region where the shear modulus of elasticity Gb' is not constant means that the shear modulus of elasticity Gb' is A region where the minimum value is less than 90% of the maximum value of the shear modulus of elasticity Gb', the shear modulus of elasticity Gb' when the strain of the test piece of the buffer layer is 300% is included in the region . 5. The sheet for forming a first protective film according to claim 1 or 2, wherein the strain of the test piece of the curable resin film obtained by the strain distribution measurement is related to the test piece of the curable resin film. In the function of the shear elastic modulus Gc' of the sheet, there is a region where the shear elastic modulus Gc' is not constant, and the region where the shear elastic modulus Gc' is not constant means that the shear elastic modulus In the area where the minimum value of the amount Gc' is less than 90% of the maximum value of the shear modulus of elasticity Gc', the shear modulus of elasticity Gc' when the strain of the test piece of the curable resin film is 300% included in the region. 6. The sheet for forming a first protective film according to claim 1 or 2, wherein the curable resin film contains a resin component, The filler content of the curable resin film is 45% by mass or less, The weight average molecular weight of the resin component is 30000 or less.

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