TWI736196B - Sheet for forming resin film, composite sheet for forming resin film, and method for regenerating silicon wafer - Google Patents

Abstract

The present invention provides a sheet for forming a resin film, which is used to attach to a silicon wafer and form a sheet of resin film on the silicon wafer, and meets the reworkability of the following requirements (I) to (III) And excellent end adhesion,

Requirement (I): The surface roughness (Ra) of the surface (α) on the side where the resin film forming sheet is attached to the silicon wafer is 50 nm or less,

Requirement (II): The adhesion force (α 1) of the surface (α) of the aforementioned resin film forming sheet to the silicon wafer is 1.0~7.0N/25mm,

Requirement (III): The surface (β ) of the aforementioned resin film forming sheet opposite to the silicon wafer attaching side is an adhesive for an adhesive sheet formed of a specific adhesive with an adhesive layer with a thickness of 10-50μm The layer adhesion ( β 1) is above 4.0N/25mm.

Description

Sheet for forming resin film, composite sheet for forming resin film, and method for regenerating silicon wafer

The present invention relates to a sheet for forming a resin film, a composite sheet for forming a resin film having the sheet for forming the resin film laminated on a support sheet, and a method for regenerating a silicon wafer.

In recent years, the manufacture of semiconductor devices using a so-called flip-chip packaging method has been proceeding. In the flip-chip method, a semiconductor chip with electrodes such as bumps mounted on the circuit surface of the substrate (hereinafter also referred to as "chip"), and the electrodes of the chip are bonded to the substrate. Therefore, there are cases where the surface (hereinafter also referred to as "the back surface of the chip") on the opposite side where the chip and the substrate are bonded is exposed.

A resin film made of an organic material is formed on the back surface of the exposed chip, and a chip with a resin film may be packaged in a semiconductor device. The resin film can perform the following functions: as a protective film to prevent cracks after the dicing step or encapsulation, or to follow the obtained chip on a backing board or another semiconductor chip or other substrate Then the function of the film.

Generally, the resin film-attached wafer is coated with a resin-containing composition solution on the back of the wafer by a spin coating method to form a coating film, and the coating film is dried and hardened to form a resin film and cut The obtained wafer with resin film is manufactured.

In addition, a curable resin film forming sheet can be attached to the back of the wafer, and the resin film forming sheet can be cured by curing the resin film forming sheet before and after the wafer is diced to obtain a resin film. And to manufacture wafers with resin film or chips with resin film.

As a resin film material that is formed on the back surface of such a wafer or the back surface of the wafer and also functions as a protective film or an adhesive film, various sheets for forming a resin film have been proposed.

For example, Patent Document 1 discloses that an energy-ray-curable protective film forming layer containing a polymer component composed of an acrylic copolymer, an energy-ray-curable component, a dye or pigment, an inorganic filler, and a photopolymerization initiator has a A wafer protection film sandwiched by two release sheets.

According to Patent Document 1, the chip protection film is irradiated with energy rays to form a protective film with good laser mark visibility, hardness, and adhesion to the wafer, and is compatible with conventional chip protection. Compared with thin films, the steps can be simplified.

In addition, Patent Document 2 discloses that a dicing tape with a substrate and an adhesive layer is colored on the adhesive layer of the dicing tape and has a dicing tape integrated crystal with a wafer backside protective film with a specific elasticity. Round back protective film.

According to Patent Document 2, the protective film for the backside of the wafer is a semiconductor In the dicing step of the bulk wafer, the holding force with the semiconductor wafer is good.

[Prior technical literature]

〔Patent Documents〕

[Patent Document 1] JP 2009-138026 A

[Patent Document 2] JP 2010-199543 A

Sometimes, in the step of attaching the protective film described in Patent Documents 1 and 2 to the wafer, when the position of the protective film attached to the wafer is shifted, foreign matter is attached to the wafer, such as A protective film is attached to the wafer with foreign matter. Under these conditions, it is difficult to reprocess (re-peel) the protective film once attached to the wafer from the wafer.

In particular, the protective film disclosed in Patent Documents 1 and 2 aims to improve the adhesion to the wafer during attachment or the retention of the wafer after attachment. Once attached to the wafer, it interacts with the wafer The round has high adhesion, so it is very difficult to reprocess.

That is, when force is applied to forcibly peel off the protective film attached to the wafer, the wafer may be damaged, or even when the protective film is peeled off without damaging the wafer, a part of the protective film may remain on the wafer.

The protective films described in Patent Documents 1 and 2 have been reviewed from the viewpoint of adhesion to the wafer at the time of attachment or retention of the wafer after attachment, but nothing has been done. Once attached to the wafer Review of the reworkability of the protective film.

In addition, not only the need to re-attach the protective film was noticed immediately after attaching the protective film and the wafer, but also the state of the laminated body with the protective film attached to the wafer after the attaching was noticed after being allowed to stand for about 24 hours. many.

After the protective film is attached to the wafer, the adhesion between the wafer and the protective film is improved as time passes, so it is generally difficult to reprocess the protective film.

In addition, we can also think about the reworkability after attaching to the silicon wafer, and use a rough-designed protective film on the surface of the wafer attaching side, so that the end of the protective film is easy to attach to the wafer. Floating or peeling occurs, resulting in deterioration of end adhesion.

The present invention was made in view of the above-mentioned problems, and the object is to provide a resin film forming sheet with excellent reworkability and end adhesion, and a support sheet having the resin film forming sheet laminated to form a resin film forming sheet Composite wafers, and methods for regenerating silicon wafers.

The inventors have found that the resin film forming sheet with adjusted adhesive force is related to the surface roughness of the surface attached to the silicon wafer and the adhesive force of the silicon wafer, as well as to the opposite to the surface. The adhesive force of the adhesive layer of the general adhesive sheet on the other surface of the side can solve the above-mentioned problems and complete the present invention.

That is, the present invention provides the following [1] to [10].

[1] A sheet for forming a resin film, which is used to attach to a silicon crystal Round, and form a thin sheet of resin film on the silicon wafer, and meet the following requirements (I) ~ (III),

Requirement (I): The surface roughness (Ra) of the surface (α) of the aforementioned resin film forming sheet on the side where the silicon wafer is attached is 50 nm or less,

Requirement (II): The adhesion force (α 1) of the surface (α) of the aforementioned resin film forming sheet to the silicon wafer is 1.0~7.0N/25mm,

Requirement (III): The surface ( β ) of the aforementioned resin film forming sheet is the opposite side of the silicon wafer attaching side to the adhesive layer of the adhesive layer formed by the adhesive with the adhesive layer ( β 1) is 4.0N/25mm or more,

The aforementioned adhesive contains 100 parts by mass of acrylic resin having structural units derived from butyl acrylate and acrylic acid and a mass average molecular weight of 600,000 to 1 million, and 0.01 to 10 parts by mass of a crosslinking agent,

The aforementioned adhesive sheet has an adhesive layer with a thickness of 10-50 μm.

[2] The sheet for forming a resin film as in [1], wherein the storage elastic modulus at 23°C is 0.10-20 GPa.

[3] The resin film forming sheet of [1] or [2], wherein the contact angle of the surface (β ) of the resin film forming sheet with respect to water is 70 to 110°.

[4] The resin film forming sheet according to any one of [1] to [3], which contains a polymer component (A) and a curable component (B).

[5] The sheet for forming a resin film according to [4], wherein the polymer component (A) contains an acrylic polymer (A1).

[6] The resin film forming sheet according to [5], wherein the acrylic polymer (A1) has a structural unit (a1) derived from an alkyl (meth)acrylate and a structural unit derived from a nitrile monomer (a2) The acrylic copolymer.

[7] The resin film forming sheet according to any one of [1] to [6], wherein it is used to form a protective film on a silicon wafer.

[8] A composite sheet for forming a resin film, which has a structure in which the resin film forming sheet according to any one of [1] to [7] is laminated on a support sheet.

[9] The composite sheet for forming a resin film according to [8], wherein the sheet for forming a resin film has a structure sandwiched by two supporting sheets.

[10] A method for regenerating silicon wafers, which is to directly attach a laminate of the surface (α) of the resin film forming sheet as in any one of [1] to [7] from the silicon wafer, and then process The method for regenerating a silicon wafer by using a sheet for forming a resin film has the following steps (1) to (2),

Step (1): a step of attaching the adhesive layer of the adhesive sheet having the base material and the adhesive layer on the surface (β) of the resin film forming sheet of the aforementioned laminate,

Step (2): Stretching the adhesive sheet attached to the surface ( β ) of the resin film forming sheet in the stretching step (1), and then processing the resin film attached to the silicon wafer for forming The step of thin slices.

Reworkability and fineness of the sheet for forming a resin film of the present invention Excellent adhesion.

Therefore, once the resin film forming sheet of the present invention is attached to a silicon wafer, when there is a need for reattachment, the silicon wafer is not damaged, and the remaining attachment can be suppressed while adhering to the silicon wafer. There is a part of the resin film forming sheet, and the resin film forming sheet can be reprocessed from the silicon wafer. As a result, the silicon wafer after reprocessing the resin film forming sheet can be reused.

In addition, the "sheet for forming a reprocessed resin film" in this specification means a sheet for forming a resin film that is once attached to a silicon wafer by peeling off again.

In addition, the "reworkability of the resin film forming sheet" means that after being attached to the silicon wafer, the silicon wafer is not damaged during reprocessing, and there is no part of the resin film forming sheet remaining on the silicon wafer. The nature of peeling.

1a, 1b, 1c, 1d: composite sheet for resin film formation

10: Sheets for resin film formation

11, 11’: Support sheet

12: Fixture then layer

[Fig. 1] A cross-sectional view of a composite sheet for forming a resin film according to an aspect of the present invention.

In the description of this specification, the values of the mass average molecular weight (Mw) and number average molecular weight (Mn) of each component are calculated by the standard polystyrene conversion value measured by the gel permeation chromatography (GPC) method, specifically based on Record the value measured by the method in the examples.

In addition, in this specification, for example, "(meth)acrylate" means the term used for both "acrylate" and "methacrylate". Use, and other similar terms are also the same.

Furthermore, "energy ray" in this specification means, for example, ultraviolet rays or electron beams, and ultraviolet rays are preferred.

〔Sheet for resin film formation〕

The resin film forming sheet of the present invention is used for attaching to a silicon wafer and forming a resin film on the silicon wafer, and satisfies the following requirements (I) to (III),

Requirement (I): The surface roughness (Ra) of the surface (α) of the aforementioned resin film forming sheet that is attached to the silicon wafer is 50 nm or less (hereinafter also simply referred to as "surface (α) surface roughness ( Ra)”),

Requirement (II): The adhesive force (α 1) of the surface (α) of the aforementioned resin film forming sheet to the silicon wafer is 1.0~7.0N/25mm (hereinafter also simply referred to as "the adhesive force of the surface (α) ( α 1)”),

Requirement (III): The surface ( β ) of the aforementioned resin film forming sheet is the opposite side of the silicon wafer attaching side to the adhesive layer of the adhesive layer formed by the adhesive with the adhesive layer ( β 1) (hereinafter also only referred to as "the adhesion force ( β 1) of the surface (β )") is 4.0N/25mm or more,

The aforementioned adhesive contains 100 parts by mass of acrylic resin having structural units derived from butyl acrylate and acrylic acid, a mass average molecular weight of 600,000 to 1 million, and 0.01 to 10 parts by mass of a crosslinking agent,

The aforementioned adhesive sheet has an adhesive layer with a thickness of 10-50 μm.

The surface (α) of the resin film forming sheet of the present invention is the surface on the side where the silicon wafer is attached, and the surface ( β ) is used to form the resin film from the silicon wafer after attaching it to the silicon wafer The adhesive surface that is reprocessed and attached to the adhesive layer of the general-purpose adhesive sheet.

In addition, the form of the sheet for forming a resin film of the present invention is not particularly limited. For example, it may be in the form of a long adhesive tape-like label, a leaf label, and the like.

In addition, the resin film forming sheet of one aspect of the present invention may be a single-layer sheet composed of one layer formed of one type of composition, or may be composed of two or more layers formed of two or more types of composition. The multi-layer sheet.

In addition, when the resin film forming sheet of one aspect of the present invention is a multi-layer sheet composed of two or more layers, the composition (α') and the surface ( β ) of the layer forming material on the surface (α) side The composition (β ') of the forming material of the side layer should meet the above-mentioned requirements (I) to (III) by adjusting the types or blending amounts of the contained components. Therefore, it is preferable that the composition (α') and the composition ( β ') are different from each other.

<Requirements (I)>

By satisfying the above-mentioned requirement (I), after the resin film forming sheet of the present invention is attached to the wafer, the floating or peeling of the end of the wafer can be suppressed, and the end adhesion is excellent.

That is, when the surface roughness (Ra) of the surface (α) exceeds 50 nm, when the obtained resin film forming sheet is attached to the silicon wafer, the adhesion to the silicon wafer is insufficient, and it becomes particularly The end of silicon wafer is easy to produce Floating or peeling, deteriorating end adhesion. Such a decrease in adhesion, especially when the end adhesion decreases, will also cause the washing water used during dicing to penetrate into the interface between the resin film forming sheet and the silicon wafer, causing contamination of the silicon wafer. The surface may be the cause of chipping during cutting.

From the above viewpoint, the surface roughness (Ra) of the surface (α) of the resin film forming sheet as one aspect of the present invention is preferably 40 nm or less, preferably 35 nm or less, more preferably 30 nm or less, most preferably It is 25nm or less.

In addition, from the viewpoint of setting the sheet for forming a resin film that improves reworkability, the surface roughness (Ra) of the surface (α) is preferably 5 nm or more, preferably 10 nm or more, and more preferably 15 nm or more .

In addition, the surface roughness (Ra) of the surface (α) in this specification is a value measured in accordance with JIS B0601:2001, and more specifically means a value measured by the method described in the examples.

In addition, the surface roughness (Ra) of the surface (α) can be adjusted by appropriately setting the type, average particle size, and content of fine particles such as inorganic fillers or colorants contained in the resin film forming sheet. . In addition, it can also be adjusted by a method of bonding the uneven surface of the release film with rough uneven surface on the surface (α) of the resin film forming sheet, and transferring the uneven shape.

<Requirements (II)>

The sheet for forming a resin film of the present invention satisfies the requirement (II), and can maintain good adhesion to the silicon wafer after being attached, especially at the ends Adhesion, which can be processed even after 24 hours.

For example, as disclosed in Patent Documents 1 and 2, the conventional resin film forming sheet used to improve the adhesion and retention of the silicon wafer in many cases, and the improvement is performed as specified in the requirement (II) The material design of the value of the adhesion of the surface (α).

However, when the adhesive force (α 1) of the surface (α) exceeds 7.0N/25mm, it tends to be difficult to reprocess the obtained resin film forming sheet after attaching it to the silicon wafer. In particular, as the time elapsed after being attached to the silicon wafer, the adhesion between the silicon wafer and the resin film forming sheet is improved. Therefore, when the resin film forming sheet is forcibly reprocessed from the silicon wafer, the The force of reprocessing may damage the silicon wafer.

On the other hand, when the adhesive force (α 1) of the surface (α) is less than 1.0N/25mm, the adhesion to the silicon wafer is insufficient, especially when the obtained resin film forming sheet is attached to the silicon wafer When it is round, it is easy to float or peel off at the end of the silicon wafer, which deteriorates the adhesion of the end.

Therefore, in the resin film forming sheet of the present invention, the adhesive force (α 1) of the surface (α) is adjusted to the range specified by the requirement (II).

The adhesive force (α 1) of the surface (α) of the resin film forming sheet of one aspect of the present invention is to improve the adhesion with the silicon wafer, especially from the end after being attached to the silicon wafer From the viewpoint of the setting of the adhesive resin film forming sheet, it is preferably 1.3N/25mm or more, preferably 1.5N/25mm or more, more preferably 1.8N/25mm or more, most preferably 2.0N/25mm or more From the viewpoint of setting the sheet for forming a resin film to improve reworkability, it is preferably 6.8N/25mm or less, preferably 6.5N/25mm or less, more preferably 6.0N/25mm or less, most preferably 5.5N/25mm or less.

In addition, the adhesive force (α 1) of the surface (α) in this specification means the value measured by the method described in the examples.

In addition, the adhesive force (α 1) of the surface (α) is an appropriate selection of polymer components, curable components, and inorganic fillers contained in the composition of the layer forming material on the surface (α) side of the resin film forming sheet. The type or content of additives and additives can be adjusted as long as they fall within the above-mentioned range. Specifically, it can be easily adjusted if consideration is given to appropriately combining the items of each component contained in the sheet for forming a resin film.

<Requirement (III)>

The sheet for forming a resin film of the present invention satisfies the requirement (III) and becomes reworkable even after about 24 hours have passed.

After attaching the resin film forming sheet of the present invention to a silicon wafer, when the resin film forming sheet needs to be peeled off again, attach a general-purpose adhesive sheet to the surface (β) of the resin film forming sheet The agent layer can reprocess the resin film forming sheet from the silicon wafer by stretching the adhesive sheet.

At this time, when the adhesive force ( β 1) of the surface (β ) is less than 4.0N/25mm, even if the adhesive layer of the adhesive sheet is attached to the surface (β ), the resin film formation is peeled off together with the adhesive sheet Flake, a part of the resin film forming flake has a high tendency to remain on the silicon wafer, and the reprocessed silicon wafer cannot be reused.

From the above viewpoint, the adhesive force ( β 1) of the surface (β ) of the resin film forming sheet of one aspect of the present invention is preferably 4.5 N/25 mm or more, more preferably 5.0 N/25 mm or more.

In addition, although the upper limit of the adhesive force of the surface (β ) is not particularly limited, the adhesive force ( β 1) of the surface (β ) is usually 20 N/25 mm or less.

The adhesive force ( β 1) of the surface (β ) of the resin film forming sheet specified in the requirement (III) is the adhesive force of the adhesive sheet with the adhesive layer formed by the adhesive to the adhesive layer,

The adhesive system contains 100 parts by mass of acrylate resin having structural units derived from butyl acrylate and acrylic acid, with a mass average molecular weight of 600,000 to 1 million, and 0.01 to 10 parts by mass of a crosslinking agent,

The adhesive sheet has an adhesive layer with a thickness of 10-50μm.

The composition of this adhesive is a specific commercially available general acrylic adhesive, and the requirement (III) is the adhesion of the specific surface ( β ) to the adhesive layer formed by the general acrylic adhesive.

In addition, the adhesive that satisfies the requirement (III) is a very general acrylic adhesive that is widely circulated in the market.

Therefore, when the resin film forming sheet of the present invention is reprocessed from a silicon wafer, the selectivity of the adhesive sheet used is very wide, and the adhesive sheet can be used with an adhesive layer composed of a general acrylic adhesive. Reprocessing.

And, more specifically, the adhesive force ( β 1) of the surface (β ) means the value measured by the method described in the examples.

Further, the adhesion surface (beta]) of (β 1) is suitably selected based resin film-forming polymer component with a surface of the sheet to form a layer of the composition (beta]) side of the material contained, the curable component, an inorganic filler, and The type or content of additives and the like can be adjusted to the above-mentioned range. Specifically, it can be easily adjusted if consideration is given to appropriately combining the items of each component contained in the sheet for forming a resin film.

One aspect of the present invention is formed of a resin film sheet, so that the resin film is then further processed to enhance the viewpoint of forming the sheet, the adhesion surface (beta]) of (β 1) than the surface-based ([alpha]) of Adhesive force (α 1) has a higher value of adhesion.

From the above point of view, the difference between the adhesive force ( β 1) and the adhesive force (α 1) [( β 1)-(α 1)] is preferably 0~8.0N/25mm, more preferably 0.1~7.0N /25mm, more preferably 0.5~6.0N/25mm, most preferably 1.5~5.5N/25mm.

The storage elastic modulus at 23°C of the resin film forming sheet of one aspect of the present invention is preferably 0.10-20 GPa, preferably 0.15-15 GPa, more preferably 0.20-10 GPa, most preferably 0.30-5.0 GPa.

If the storage modulus of elasticity is 0.10GPa or more, after attaching the resin film forming sheet to the silicon wafer, when peeling it off again, the resin film forming sheet is prevented from being deformed such as wire drawing, and no part remains on the silicon wafer The sheet for forming a resin film can be peeled off the sheet for forming a resin film.

On the other hand, if the storage elastic modulus is 20 GPa or less, the adhesion to the silicon wafer can be set well.

In addition, the storage elastic modulus of the resin film forming sheet in this specification means the value measured by the method described in the examples.

The contact angle of the surface (β ) of the resin film forming sheet of the present invention with respect to water is preferably 70 to 110° from the viewpoint of the resin film forming sheet for improving reworkability, which is more Preferably it is 75~100°, more preferably 80~95°, most preferably 83~93°.

In addition, in this specification, the contact angle of the surface (β ) of the resin film forming sheet with respect to water means the value measured by the method described in the examples.

<Components of sheet for forming resin film>

The sheet for forming a resin film of one aspect of the present invention is not particularly limited as long as it satisfies the requirements (I) to (III) and has a surface (α) and a surface ( β ), but it contains a polymer component (A) and The curable component (B) is preferable.

Furthermore, the resin film forming sheet of one aspect of the present invention does not impair the effects of the present invention from the viewpoint of satisfying the formation surface (α) and surface (β) of the requirements (I) to (III) While the above-mentioned components (A) and (B) are contained within the range, it may also contain inorganic fillers (C), colorants (D), coupling agents (E), leveling agents (F), and general additives ( G) One or more types.

Hereinafter, the above-mentioned components (A) to (G) which can be the constituent components of the resin film forming sheet of one aspect of the present invention will be explained.

〔Polymer component (A)〕

In this specification, "polymer component" means a compound having a mass average molecular weight (Mw) of 20,000 or more and having at least one type of repeating unit.

The resin film forming sheet used in one aspect of the present invention contains the polymer component (A) to impart warpability and film forming properties, and has good sheet-like shape maintenance. As a result, the storage elastic modulus at 23°C of the resin film forming sheet can be adjusted to the above-mentioned range.

As the mass average molecular weight (Mw) of the polymer component (A), from the viewpoint of adjusting the storage elastic modulus at 23°C of the obtained resin film forming sheet to the above-mentioned range, it is preferably 20,000 or more. Preferably, it is 20,000 to 3 million, more preferably 50,000 to 2 million, and most preferably 100,000 to 1.5 million.

The content of the polymer component (A) in the resin film forming sheet of one aspect of the present invention is relative to the total amount (100% by mass) of the resin film forming sheet, preferably 5-50% by mass, more preferably 8-40% by mass, more preferably 10-35% by mass, most preferably 15-30% by mass.

In addition, in this specification, "the content of the component (A) relative to the total amount of the resin film forming sheet" is the same as the "component relative to the total amount of active ingredients in the composition of the resin film forming sheet ( The content of A)" has the same meaning, and the content of other ingredients explained below is also synonymous.

That is, the phrase "relative to the total amount of the resin film forming sheet (100% by mass)" with respect to the content of each component specified can be replaced with "relative to the composition of the forming material of the resin film forming sheet" Of the active ingredients The phrase "total amount (100% by mass)" is synonymous with the specific content.

Furthermore, the above-mentioned "active ingredient" means the removal of components that directly and indirectly react with solvents in the composition or that do not affect the physical properties of the formed flakes, and specifically means solvents such as water and organic solvents. Other ingredients.

As the polymer component (A), it is preferable to contain an acrylic polymer (A1), and it may also contain polyester, phenoxy resin, polycarbonate, polyether, polyurethane, and polysilicon other than the acrylic polymer (A1). Non-acrylic polymers such as oxanes and rubber polymers (A2).

These polymer components can be used individually or in combination of 2 or more types.

As for the total amount (100% by mass) of the polymer component (A) contained in the resin film forming sheet of one aspect of the present invention, the content of the acrylic polymer (A1) is preferably 50-100% by mass, It is preferably from 60 to 100% by mass, more preferably from 70 to 100% by mass, and most preferably from 80 to 100% by mass.

(Acrylic polymer (A1))

The mass average molecular weight (Mw) of the acrylic polymer (A1) is based on imparting warpability and film forming properties to the resin film forming sheet, and adjusting the storage elastic modulus of the resin film forming sheet at 23°C to the above range From a standpoint, it is preferably 20,000 to 3 million, preferably 100,000 to 1.5 million, more preferably 150,000 to 1.2 million, and most preferably 250,000 to 1 million.

The acrylic polymer (A1) has a structural unit derived from an alkyl (meth)acrylate from the viewpoint of adjusting the adhesive force (α 1) and ( β 1) of the resin film forming sheet to the above range The acrylic polymer of (a1) is preferable, especially from the viewpoint of adjusting the adhesive force (α 1) of the resin film forming sheet to the above range, it has the structural unit (a1) and a nitrile-based monomer The acrylic copolymer of the structural unit (a2) is more preferable.

In addition, the acrylic polymer (A1) used in one aspect of the present invention may have, in addition to the structural units (a1) and (a2), an alkyl (meth)acrylate and a monomer that is not equivalent to a nitrile It is derived from the structural unit (a3) of other monomers.

In addition, the acrylic polymer (A1) can be used alone or in combination of two or more kinds.

In addition, when the acrylic polymer (A1) is a copolymer, the morphology of the copolymer may be any of a block copolymer, a random copolymer, an alternating copolymer, and a graft copolymer.

(Structural unit (a1))

As the carbon number of the alkyl group of the alkyl (meth)acrylate constituting the structural unit (a1), from the viewpoint of imparting warpability and film forming properties to the resin film forming sheet, it is preferably 1 to 18, which is more Preferably it is 1-12, more preferably 1-8.

Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate Acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, etc.

Moreover, these alkyl (meth)acrylates can be used individually or in combination of 2 or more types.

Among these, alkyl (meth)acrylates having an alkyl group having 1 to 3 carbon atoms are preferred, and methyl (meth)acrylates are more preferred.

The content of structural units (a1-1) derived from alkyl alkyl (meth)acrylates with carbon numbers of 1 to 3 in the acrylic polymer (A1) is relative to the total content of the acrylic polymer (A1) The structural unit (100% by mass) is preferably 5 to 99% by mass, preferably 10 to 98% by mass, more preferably 20 to 97% by mass, and most preferably 25 to 97% by mass.

The content of the structural unit (a1) in the acrylic polymer (A1) is relative to the total structural unit (100% by mass) of the acrylic polymer (A1), preferably 50% by mass or more, more preferably 50~99% by mass %, more preferably 55 to 98% by mass, most preferably 60 to 97% by mass.

(Structural unit (a2))

Examples of the nitrile monomer constituting the structural unit (a2) include (meth)acrylonitrile, α-chloro(meth)acrylonitrile, α-ethoxy(meth)acrylonitrile, fumaronitrile, and the like.

In addition, these nitrile-based single systems can be used alone or in combination of two or more types.

Among these, (meth)acrylonitrile is preferred.

Acrylic polymer (A1) is derived from nitrile monomer The content of the structural unit (a2) is relative to the total structural unit (100% by mass) of the acrylic polymer (A1), preferably 1-50% by mass, preferably 5-45% by mass, more preferably 10~42 % By mass, more preferably 15-40% by mass, most preferably 20-35% by mass.

If the content of the structural unit (a2) is 1% by mass or more, it is easy to adjust the adhesive force (α 1) of the surface (α) of the obtained resin film forming sheet to the above-mentioned range. On the other hand, if the content of the structural unit (a2) is 50% by mass or less, it is easy to adjust the adhesive force ( β 1) of the surface (β ) of the resin film forming sheet to the above-mentioned range.

(Structural unit (a3))

Acrylic polymer (A1) is within the range that does not impair the effect of the present invention. In addition to the above-mentioned structural units (a1) and (a2), alkyl (meth)acrylate and nitrile monomers may also be derived from It is not equivalent to the structural unit (a3) of other monomers.

Examples of other monomers constituting the structural unit (a3) include functional group-containing monomers having functional groups such as hydroxyl group-containing monomers, carboxyl group-containing monomers, and epoxy group-containing monomers; vinyl acetate and vinyl propionate And other vinyl ester monomers; olefin monomers such as ethylene, propylene, and isobutylene; aromatic vinyl monomers such as styrene, methyl styrene, and vinyl toluene: diene monomers such as butadiene and isoprene体等。 Body and so on.

From the viewpoint of adjusting the adhesive force (α 1) and ( β 1) of the resin film forming sheet to the above range, the acrylic polymer (A1) used in one aspect of the present invention contains a monomer derived from a hydroxyl group. The structural unit (a3-1) of the body is preferable.

Examples of monomers containing hydroxyl groups include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl Hydroxyalkyl (meth)acrylates such as methyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.; vinyl alcohol, allyl alcohol, etc. Unsaturated alcohols, etc.

Among these, 2-hydroxyethyl (meth)acrylate is preferred.

The content of the structural unit (a3-1) derived from the hydroxyl-containing monomer in the acrylic polymer (A1) is based on the viewpoint of adjusting the adhesive force (α 1) and (β 1) of the resin film forming sheet to the above range In terms of the total structural unit (100% by mass) of the acrylic polymer (A1), it is preferably 0.5-30% by mass, preferably 1-25% by mass, more preferably 2-20% by mass, most preferably It is 3-15% by mass, particularly preferably 3.5-12% by mass.

Furthermore, when the content of the structural unit derived from the epoxy group-containing monomer in the acrylic polymer (A1) increases, the adhesion between the obtained resin film forming sheet and the silicon wafer is improved, and the adhesion is improved The tendency of the value of force (α 1). Therefore, the content of the structural unit derived from the epoxy group-containing monomer in the acrylic polymer (A1) is as small as possible.

The content of the structural unit (a3-2) derived from the epoxy group-containing monomer in the acrylic polymer (A1) used as one aspect of the present invention is based on the above-mentioned point of view, relative to the acrylic polymer ( The total structural unit (100% by mass) of A1) is preferably 0 to 15% by mass, preferably 0 to 10% by mass, more preferably 0 to 5% by mass, and most preferably 0 to 3.5% by mass.

Examples of epoxy group-containing monomers include glycidyl (meth)acrylate, β -methylglycidyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl(meth)acrylate, (Meth)acrylate containing epoxy groups such as acrylate and 3-epoxycyclo-2-hydroxypropyl (meth)acrylate; glycidyl crotonate, allyl glycidyl ether Containing non-propylene-based epoxy monomers, etc.

When an epoxy-based thermosetting component is used as the curable component (B) described later, the carboxyl group reacts with the epoxy group in the epoxy-based thermosetting component, so the acrylic polymer (A1) is derived from The content of the structural unit of the carboxyl group-containing monomer is as small as possible.

When an epoxy-based thermosetting component is used as the curable component (B), the content of the structural unit (a3-3) derived from the carboxyl group-containing monomer used in one aspect of the present invention is relative to the acrylic polymer ( The total structural unit (100% by mass) of A1) is preferably 0-10% by mass, preferably 0-5% by mass, more preferably 0-2% by mass, and most preferably 0% by mass (without structural unit ( a3-3)).

In addition, in this specification, the acrylic polymer system with a mass average molecular weight of 20,000 or more derived from the epoxy-containing monomer has a thermosetting property, but it is not a curable component (B) and is included in the polymer The concept of ingredient (A).

As a carboxyl group-containing monomer, (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid, etc. are mentioned, for example.

The content of the structural unit (a3) in the acrylic polymer (A1) used in one aspect of the present invention is relative to the total structural unit (100% by mass) of the acrylic polymer (A1), preferably 0-30 mass %, preferably 1-20% by mass, more preferably 2-10% by mass.

(Non-acrylic resin (A2))

The sheet for forming a resin film according to one aspect of the present invention may optionally contain a non-acrylic polymer (A2) as a polymer component other than the acrylic polymer (A1) described above.

Examples of the non-acrylic polymer (A2) include polyester, phenoxy resin, polycarbonate, polyether, polyurethane, polysiloxane, rubber-based polymer, and the like.

These non-acrylic polymers (A2) can be used alone or in combination of two or more kinds.

The mass average molecular weight (Mw) of the non-acrylic polymer (A2) is preferably 20,000 or more, preferably 20,000 to 100,000, and more preferably 20,000 to 80,000.

〔Sclerosing component (B)〕

The curable component (B) is a compound whose mass average molecular weight (Mw) is less than 20,000 by hardening the sheet for forming a resin film and sharing the task of forming a hard resin film.

The resin film forming sheet used in the present invention is preferably used as the curable component (B), and preferably contains at least one of a thermosetting component (B1) and an energy ray curable component (B2). From the viewpoint of coloring of the formed resin film, the viewpoint of allowing the curing reaction to proceed sufficiently, and the viewpoint of reducing the cost, it contains a thermosetting component (B1) is better.

As a thermosetting component (B1), it is preferable to contain the compound which has a functional group which reacts by heating at least, and it is more preferable to contain the compound (B11) which has an epoxy group.

In addition, the energy ray curable component (B2) preferably contains a compound (B21) having a functional group that reacts by energy ray irradiation.

The functional groups with these curable components react with each other, and harden is achieved by forming a three-dimensional mesh structure.

When used in combination with component (A), the mass average molecular weight (Mw) of the curable component (B) can suppress the viscosity of the composition of the forming material of the resin film forming sheet and improve the workability. From a viewpoint, it is preferably less than 20,000, preferably 10,000 or less, and more preferably 100 to 10,000.

(Thermosetting component (B1))

As the thermosetting component (B1), epoxy-based thermosetting components are preferred.

The epoxy-based thermosetting component is preferably a compound having an epoxy group (B11) in combination with a thermosetting agent (B12).

Examples of the compound (B11) having an epoxy group (hereinafter, also referred to as "epoxy compound (B11)") include, for example, polyfunctional epoxy resins, bisphenol A, diglycidyl ether and hydrogenated products thereof, Cresol novolac epoxy resin, novolac epoxy resin, dicyclopentadiene epoxy resin, biphenyl epoxy resin, bisphenol A epoxy resin, bisphenol F Type epoxy resins, phenylene skeleton type epoxy resins, and other epoxy compounds having two or more functions in the molecule.

These epoxy compounds (B11) can be used individually or in combination of 2 or more types.

Among them, from the viewpoint of adjusting the adhesive force (α 1) and ( β 1) of the resin film forming sheet to the above-mentioned range, they contain selected from novolak type epoxy resins and biphenyl type epoxy resins. One or more types are preferable, especially from the viewpoint of adjusting the adhesive force (α 1) of the resin film forming sheet to the above range, it is preferable to contain a biphenyl type epoxy resin, and a biphenyl arane type ring Oxygen resin is better.

The total content of one or more selected from novolak-type epoxy resins and biphenyl-type epoxy resins is based on the total amount (100% by mass) of the epoxy compound (B11), preferably 70-100% by mass, It is preferably from 80 to 100% by mass, more preferably from 90 to 100% by mass, and most preferably from 95 to 100% by mass.

In addition, from the viewpoint of adjusting the adhesive force (α 1) of the resin film forming sheet to the above range, the content of the biphenyl type epoxy resin is relative to the total amount (100% by mass) of the epoxy compound (B11) ), preferably 70-100% by mass, more preferably 80-100% by mass, more preferably 90-100% by mass, most preferably 95-100% by mass.

The content of the epoxy compound (B11) is relative to 100 parts by mass of the component (A), preferably 1 to 500 parts by mass, preferably 3 to 300 parts by mass, more preferably 5 to 150 parts by mass, and most preferably 10~ 100 parts by mass.

(Thermal hardener (B12))

The thermosetting agent (B12) functions as a curing agent for the epoxy compound (B11).

It is preferable as a compound which has 2 or more functional groups which can react with an epoxy group in 1 molecule of a thermosetting agent.

As this functional group, a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, acid anhydride, etc. are mentioned. Among these, a phenolic hydroxyl group, an amino group, or an acid anhydride is preferable, a phenolic hydroxyl group and an amino group are preferable, and an amino group is more preferable.

Examples of the phenol-based thermosetting agent having a phenol group include polyfunctional phenol resins, biphenols, novolak-type phenol resins, dicyclopentadiene-type phenol resins, neophenol-type phenol resins, and aralkyl-type phenol resins.

Examples of the amine-based thermosetting agent having an amino group include dicyanodiamide (DICY) and the like.

These thermosetting agents (B12) can be used alone or in combination of two or more kinds.

Among these, from the viewpoint of adjusting the adhesive strength (α 1) and ( β 1) of the resin film forming sheet to the above-mentioned range, it is preferable to contain a phenol-based thermosetting agent.

The content of the phenol-based thermosetting agent is relative to the total amount (100% by mass) of the thermosetting agent (B12), preferably 50-100% by mass, preferably 70-100% by mass, more preferably 80-100% by mass , The best is 90-100% by mass.

The content of thermal hardener (B12) is relative to epoxy compound (B11) 100 parts by mass, preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass.

Further, one aspect of the present invention is formed of a resin film sheet, and (β 1) adjusts the film-forming resin of the adhesion of the sheet (α 1) to view the above range, the epoxy compound (B1 ) It contains a biphenyl type epoxy resin, and contains a phenol-based thermosetting agent as the thermosetting agent (B12), and it is preferable to use two components in combination.

Furthermore, at this time, it is more preferable to contain an acrylic polymer (A1) having a structural unit (a2-1) derived from a nitrile monomer as the polymer component (A).

(Hardening accelerator (B13))

The sheet for forming a resin film according to one aspect of the present invention may contain a hardening accelerator (B13) from the viewpoint of adjusting the hardening speed by heating the sheet.

The curing accelerator (B13) is used as the thermosetting component (B1), and an epoxy compound (B11) is preferably used in combination.

Examples of the hardening accelerator (B13) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylethanolamine, and tris(dimethylmethylamine)phenol; 2-methylimidazole , 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, etc. Imidazoles; organic phosphines such as tributyl phosphine, diphenyl phosphine, and triphenyl phosphine; tetraphenyl boron salts such as tetraphenyl phosphonium tetraphenyl borate, triphenyl phosphine tetraphenyl borate, etc.

These hardening accelerators (B13) can be used alone or in combination of two or more use.

The content of the hardening accelerator (B13) is based on the total amount of the epoxy compound (B11) and the thermosetting agent (B12) from the viewpoint of improving the adhesiveness of the resin film formed by the resin film forming sheet, which is 100 mass Parts, preferably 0.01-10 parts by mass, preferably 0.1-6 parts by mass, more preferably 0.3-4 parts by mass.

(Energy ray hardening component (B2))

As the energy ray curable component (B2), although the compound (B21) having a functional group that reacts by energy ray irradiation can be used alone, it is better to use a photopolymerization initiator (B22) combined with the compound (B21). good.

(Compound (B21) having a functional group that reacts by energy ray irradiation)

Examples of the compound (B21) having a functional group that reacts by energy ray irradiation (hereinafter also referred to as "energy ray reactive compound (B21)") include trimethylolpropane triacrylate and pentaerythritol triacrylate Esters, pentaerythritol tetraacrylate, dipentaerythritol monohydroxy pentaacrylate, dipentaerythritol hexaacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, oligoester acrylate, Polyurethane acrylate oligomer, epoxy acrylate, polyether acrylate, itaconic acid oligomer, etc.

These energy ray reactive compounds (B21) can be used alone or in combination 2 More than one kind of use.

In addition, the mass average molecular weight (Mw) of the energy ray reactive compound (B21) is preferably 100 to 30,000, more preferably 300 to 10,000.

The content of the energy ray reactive compound (B21) is based on 100 parts by mass of the component (A), preferably 1 to 1500 parts by mass, and more preferably 3 to 1200 parts by mass.

(Photopolymerization initiator (B22))

With the aforementioned photopolymerization initiator (B22) used in combination with the energy ray reactive compound (B21), the polymerization curing time is shortened, and the resin film forming sheet can be cured even if the amount of light exposure is reduced.

As a photopolymerization initiator (B22), a benzoin compound, an acetophenone compound, an phosphine oxide compound, a titanocene compound, a thioxanthone compound, a peroxide compound, etc. are mentioned, for example.

As more specific photopolymerization initiators, for example, 1-hydroxycyclohexyl phenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl Thioether, tetramethylthiuram, azobisisobutyronitrile, dibenzyl, butanedione, β -creeping anthraquinone, 2,4,6-trimethylbenzyl diphenyl phosphine oxide, etc.

These photopolymerization initiators can be used alone or in combination of two or more kinds.

The content of the photopolymerization initiator (B22) is such that the curing reaction of the resin film forming sheet is sufficiently advanced. From the viewpoint of suppressing the generation of residues, it is preferably relative to 100 parts by mass of the energy ray reactive compound (B21) It is 0.1 to 10 parts by mass, preferably 1 to 5 parts by mass.

The content of the curable component (B) in the resin film forming sheet of one aspect of the present invention is relative to the total amount (100% by mass) of the resin film forming sheet, preferably 5-50% by mass, and more preferably 8-40% by mass, more preferably 10-30% by mass, most preferably 12-25% by mass.

In addition, the "content of the curable component (B)" refers to the epoxy compound (B11), the thermosetting agent (B12), the thermosetting component (B1) containing the curing accelerator (B13), and energy rays The total content of the reactive compound (B21) and the energy ray curable component (B2) containing the photopolymerization initiator (B22).

The total content of the polymer component (A) and the curable component (B) in the resin film forming sheet as one aspect of the present invention is preferably relative to the total amount (100% by mass) of the resin film forming sheet 40% by mass or more, preferably 50% by mass or more, more preferably 60% by mass or more, most preferably 70% by mass or more.

〔Inorganic filler (C)〕

The sheet for forming a resin film according to an aspect of the present invention may further contain an inorganic filler (C).

By containing the inorganic filler (C), the thermal expansion parameter of the resin film formed by the resin film forming sheet can be adjusted to an appropriate range, and the thermal expansion parameter of the chip with the resin film can be optimized, and the embedded chip can be improved The reliability of semiconductor devices. In addition, the moisture absorption rate of the resin film formed of the resin film forming sheet can also be reduced.

As the inorganic filler (C), for example, silica, oxide Powders such as aluminum, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride, etc., spheroidized microbeads, single crystal fibers, glass fibers, etc.

These inorganic fillers (C) can be used individually or in combination of 2 or more types.

The silica and alumina are preferred.

As the average particle diameter of the inorganic filler (C), from the viewpoint of adjusting the surface roughness (Ra) of the surface (α) of the resin film forming sheet to the above range, it is preferably 400 nm or less, preferably 300 nm or less, It is more preferably 200 nm or less, and most preferably 100 nm or less. On the other hand, from the viewpoint of setting the reliability of a resin film-attached wafer manufactured using a resin film forming sheet, it is preferably 10 nm or more, and more preferably Above 20nm.

In addition, the average particle size of the inorganic filler (C) in this specification is a value measured using a laser diffraction scattering type particle size distribution measuring device, and means the volume median particle size (D ₅₀ ).

The content of the inorganic filler (C) in the resin film forming sheet of one aspect of the present invention is from the viewpoint of adjusting the surface roughness (Ra) of the surface (α) of the resin film forming sheet to the above-mentioned range. Relative to the total amount (100% by mass) of the resin film forming sheet, preferably 0-50% by mass, more preferably 0-45% by mass, more preferably 0-40% by mass, most preferably 0-30% by mass .

In addition, when the resin film forming sheet of one aspect of the present invention is a cladding body composed of two or more layers formed of two or more compositions, it is included on the surface (α) side of the resin film forming sheet The form of layers The inorganic filler (C) in the composition of the material reduces the average particle size and also reduces the content, and it is better to adjust the surface roughness (Ra) of the surface (α).

On the other hand, in the composition of the layer forming material on the surface (β ) side that does not affect the surface roughness (Ra) of the surface (α), inorganic particles with an average particle size of 0.01 μm or more can also be blended. Filler (C').

The average particle size of the inorganic filler (C') is usually 0.01 to 5 μm, preferably 0.02 to 3 μm.

〔Colorant (D)〕

The sheet for forming a resin film of one aspect of the present invention may further include a colorant (D).

When the resin film forming sheet contains the coloring agent (D), when the semiconductor chip with the resin film formed from the resin film forming sheet is incorporated into the machine, the infrared rays generated by the surrounding devices can be shielded, and the semiconductor chip can be prevented from being damaged. Wrong action.

As the colorant (D), organic or inorganic pigments and dyes can be used.

As the dye, any one of acid dyes, reactive dyes, direct dyes, disperse dyes, and cationic dyes can be used.

In addition, there are no particular restrictions on the pigment, and it can be suitably selected from conventional pigments and used.

From the viewpoint of good shielding properties of electromagnetic waves or infrared rays, and improved recognition by laser marking method, black pigments are preferable.

As black pigments, although examples include carbon black, iron oxide, and dioxygen Manganese, aniline black, activated carbon, etc., but from the viewpoint of improving the reliability of semiconductor wafers, carbon black is preferable.

Moreover, these coloring agents (D) can be used individually or in combination of 2 or more types.

The average particle diameter of the colorant (D) is preferably 400 nm or less, preferably 300 nm or less from the viewpoint of adjusting the surface roughness (Ra) of the surface (α) of the resin film forming sheet to the above-mentioned range. It is more preferably 200 nm or less, most preferably 100 nm or less, and more preferably 10 nm or more, and more preferably 20 nm or more.

In addition, the average particle size of the colorant (D) in this specification is a value measured by a laser diffraction scattering type particle size distribution measuring device, and means the volume median particle size (D ₅₀ ).

The content of the coloring agent (D) in the resin film forming sheet of one aspect of the present invention is relative to the total amount (100% by mass) of the resin film forming sheet, preferably 0.01-30% by mass, more preferably 0.05 ~25% by mass, more preferably 0.1-15% by mass, most preferably 0.15-5% by mass.

〔Coupling agent (E)〕

The sheet for forming a resin film of one aspect of the present invention may further include a coupling agent (E).

By containing the coupling agent (E), the heat resistance of the obtained resin film formed of the resin film forming sheet is not impaired, and the water resistance can also be improved. In addition, it also improves the adhesion to the end of the silicon wafer after attachment.

As a coupling agent (E), with component (A) or component The functional group reaction compound of (B) is preferable, and the silane coupling agent is more preferable.

As the silane coupling agent, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidylmethyldiethoxysilane, β -(3,4-epoxycyclohexyl)ethyltrimethoxysilane , Γ-(methacrylic acid) trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl) -γ-Aminopropylmethyl diethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ -Mercaptopropyl methyl dimethyl dimethyl oxysilane, bis (3-triethoxy silyl propyl) tetrasulfane, methyl trimethoxy silane, methyl triethoxy silane, ethylene trimethoxy silane, ethylene triethyl Oxyoxysilane, imidazole silane, etc.

These coupling agents (E) can be used individually or in combination of 2 or more types.

As the coupling agent (E), an oligomer type coupling agent is preferred.

As the molecular weight of the coupling agent (E) which also contains the oligomer type coupling agent, it is preferably 100 to 15000, preferably 150 to 10000, more preferably 200 to 5000, still more preferably 250 to 3000, most preferably 350 ~2000.

In addition, it is conceivable that by containing the coupling agent (E), when the silicon wafer or resin film forming sheet of the body contains the inorganic filler (C), it bonds with the surface of the inorganic filler (C) to improve the adhesion or Cohesiveness also improves the adhesive force (α 1) of the resin film forming sheet.

Therefore, from the viewpoint of obtaining a sheet for forming a resin film with excellent reworkability, the content of the coupling agent (E) in the sheet for forming a resin film according to one aspect of the present invention should be as small as possible.

The content of the coupling agent (E) in the resin film forming sheet of one aspect of the present invention is relative to the total amount (100% by mass) of the resin film forming sheet, and from the above viewpoint, it is preferably 3.0% by mass or less , Preferably 1.5% by mass or less, more preferably 0.8% by mass or less, and most preferably 0.3% by mass or less. From the viewpoint of part adhesion and from the viewpoint of adjusting the adhesive force ( β 1) of the surface (β ) of the resin film forming sheet to the above range, it is preferably 0.01% by mass or more, more preferably 0.05% by mass % Or more, more preferably 0.10 mass% or more.

〔Leveling agent (F)〕

The sheet for forming a resin film of one aspect of the present invention may further contain a leveling agent (F).

By containing the leveling agent (F), the adhesive force (α 1) of the surface (α) of the obtained resin film forming sheet can be easily adjusted to the above-mentioned range.

As the leveling agent (F), for example, silicone-based leveling agents, fluorine-based leveling agents, propylene-based leveling agents, ethylene-based leveling agents, and fluorine-based and propylene-based leveling agents have been combined. Wait.

These leveling agents (F) can be used individually or in combination of 2 or more types.

From the viewpoint that the adhesive force (α 1) of the surface (α) of the resin film forming sheet can be easily adjusted to the above-mentioned range, it is preferable to contain a silicone-based leveling agent.

In addition, when the resin film forming sheet contains a leveling agent (F), the adhesive force (α 1) of the surface (α) can be easily adjusted to the above range, and the adhesive force ( β 1) of the surface (β) will be reduced. There is a concern about the reworkability of the sheet for forming a resin film. Therefore, on the surface ( β ) side of the sheet for forming a resin film, the content of the leveling agent should be as small as possible.

From the viewpoint of adjusting the adhesive force (α 1) of the surface (α) of the obtained resin film forming sheet to the above range, the content of the leveling agent (F) is relative to the total amount of the resin film forming sheet (100% by mass), preferably 0.010% by mass or more, more preferably 0.050% by mass or more, more preferably 0.100% by mass or more.

In addition, from the viewpoint of adjusting the adhesive force ( β 1) of the surface (β ) of the resin film forming sheet to the above range, the content of the leveling agent (F) is relative to the total amount of the resin film forming sheet (100% by mass), preferably 0.500% by mass or less, more preferably 0.300% by mass or more, more preferably 0.200% by mass or more.

Furthermore, from the viewpoint of adjusting the adhesive force (α 1) and ( β 1) of the resin film forming sheet in a good balance, when the resin film forming sheet of the present invention contains a leveling agent, it is used as the resin One aspect of the film forming sheet is preferably a multi-layer sheet having a layer formed of a composition (α') containing a leveling agent and a layer formed of a composition (β') substantially not containing a leveling agent .

The composition (α') becomes the forming material of the layer on the surface (α) side of the resin film forming sheet, and the composition ( β ') becomes the forming material of the layer on the surface (β ) side of the resin film forming sheet.

The content of the leveling agent (F) in the composition (α') is based on the viewpoint of adjusting the adhesive force (α 1) of the surface (α) to the above range, relative to the effective ingredients contained in the composition (α') The total amount (100 mass %), preferably 0.010-10 mass%, more preferably 0.050-7 mass%, more preferably 0.100-5 mass%, most preferably 0.150-2 mass%.

On the other hand, the content of the leveling agent (F) in the composition (β ') is from the viewpoint of adjusting the adhesive force ( β 1) of the surface (β ) to the above range, relative to the composition ( β ') ) The total amount (100% by mass) of the active ingredients contained is preferably 0~0.500% by mass, more preferably 0~0.100% by mass, more preferably 0~0.010% by mass, and most preferably 0~0.001% by mass.

〔General purpose additives (G)〕

In the resin film forming sheet used in one aspect of the present invention, within the range that does not impair the effects of the present invention, general additives (G) may be contained in addition to the above-mentioned components as necessary.

Examples of general-purpose additives (G) include crosslinking agents, plasticizers, antistatic agents, antioxidants, ion trapping agents, degassing agents, chain transfer agents, and the like.

It is preferable that these contain a crosslinking agent.

Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, metal chelate-based crosslinking agents, amine-based crosslinking agents, and amine-based resin-based crosslinking agents Wait. These crosslinking agents can be used alone or in combination of two or more kinds.

The respective content of the general additives (G) in the resin film forming sheet of one aspect of the present invention is relative to the total amount of the resin film forming sheet (100% by mass), preferably 0-10% by mass. Jiawei 0 to 5 mass%, more preferably 0 to 2 mass%.

<Manufacturing Method of Sheet for Forming Resin Film>

The manufacturing method of the resin film forming sheet|seat which is one aspect of this invention is not specifically limited, It can manufacture by a conventional method.

For example, after preparing a resin film forming composition containing the above-mentioned components as a forming material for a resin film forming sheet, an organic solvent is appropriately added and diluted to obtain a solution of the resin film forming composition. Then, the solution of the composition for forming a resin film is coated on a support sheet by a conventional coating method to form a coating film, and the coating film is dried to produce a sheet for forming a resin film.

In addition, when the resin film forming sheet of one aspect of the present invention is a two or more layered body, the method for producing the resin film forming sheet includes, for example, applying resin to two or more supporting sheets. A method of forming a coating film from a solution of the composition for film formation, and then laminating the coating film to form a build-up film of the coating film, and then drying it to manufacture it.

Examples of the organic solvent used for the preparation of the solution of the composition for forming a resin film include toluene, ethyl acetate, methyl ethyl ketone, and the like.

The solid content concentration of the solution of the resin film forming composition when the organic solvent has been blended is preferably 10 to 80% by mass, preferably 20 to 70% by mass, and more preferably 30 to 65% by mass.

Examples of coating methods include spin coating, spray coating, bar coating, knife coating, roll coating, roll coating, knife coating, and die coating. Coating method, gravure coating method, etc.

The thickness of the resin film forming sheet of one aspect of the present invention can be appropriately set depending on the application, and is preferably 3 to 300 μm, preferably 5 to 250 μm, and more preferably 7 to 200 μm.

In addition, when the resin film forming sheet is a multi-layer sheet composed of two or more layers, the total thickness of the multi-layer sheet is also preferably within the above-mentioned range.

<Use of sheet for forming resin film>

The resin film forming sheet of one aspect of the present invention is attached to the back surface of a workpiece such as a flip chip semiconductor wafer or a silicon wafer such as a semiconductor wafer, and a resin film can be formed on the workpiece. This resin film has a function as a protective film for protecting the back surface of a semiconductor wafer or a workpiece such as a semiconductor wafer. For example, when attached to a semiconductor wafer, the resin film has the function of reinforcing the wafer, so it can prevent damage to the wafer.

That is, the resin film forming sheet of one aspect of the present invention is preferably a protective film forming sheet for forming a protective film on a silicon wafer.

In addition, the resin film formed from the resin film forming sheet of one aspect of the present invention may also be provided with a function as an adhesive film. That is, when the resin film formed using the resin film forming sheet of one aspect of the present invention functions as an adhesive film, a wafer with the resin film can be attached to a backing board or another semiconductor wafer or other substrates. On the material (on the wafer loading part), the productivity can be improved for the manufacture of semiconductor devices.

That is, in order to form an adhesive film on a silicon wafer, the resin film forming sheet of one aspect of the present invention can also be used as an adhesive film forming sheet.

[Composition of composite sheet for resin film formation]

The composite sheet for forming a resin film of the present invention (hereinafter, also simply referred to as a "composite sheet") has a structure in which the resin film forming sheet of the present invention capable of forming the above-mentioned resin film is laminated on a support sheet.

In addition, there is no particular limitation on the form of the composite sheet of one aspect of the present invention. For example, it may be in the form of a long adhesive tape, leaf label, and the like.

Fig. 1 is a cross-sectional view of a composite sheet for forming a resin film according to one aspect of the present invention.

As a composite sheet of one aspect of the present invention, as shown in FIG. 1(a), a composite sheet 1a having a structure in which a resin film forming sheet 10 is directly laminated on a support sheet 11 is exemplified.

The shape of the resin film forming sheet 10 of the composite sheet, which is one aspect of the present invention, may have approximately the same shape as the silicon wafer of the object or the shape of the silicon wafer.

In addition, although the composite sheet 1a of FIG. 1(a) has approximately the same shape as the supporting sheet 11 and the resin film forming sheet 10, as shown in FIG. 1(b), the shape of the resin film forming sheet 10 may also be more The supporting sheet 11 is a composite sheet 1b with a smaller shape.

In addition, as one aspect of the composite sheet of the present invention, as shown in FIG.

When the ring-shaped jig adhesive layer 12 is attached to a jig such as a ring frame, it is set for the purpose of improving the adhesive force of the jig. It can be provided with a base material (Core material) is formed by adhesive sheets or adhesives on both sides.

In addition, in the composite sheet 1c shown in FIG. 1(c), with respect to the composite sheet 1a of FIG. It can also be enumerated in the composite sheet 1b of FIG. 1(b) where the supporting sheet 11 is provided with a clamp adhesive layer 12 on the surface of the composite sheet.

As shown in Fig. 1(d), a composite sheet as one aspect of the present invention can also be a composite sheet 1d having a structure sandwiched between two supporting sheets 11, 11' as a resin film forming sheet 10.

In addition, as in the structure of the composite sheet 1d, the exposed resin film forming sheet 10 of the composite sheet 1b of FIG. 1(b) may be provided with the support sheet 11 as another support sheet.

In addition, the surface of the resin film forming sheet 10 and the surface of the jig adhesive layer 12 of the composite sheet 1c shown in FIG.

<Support sheet>

The supporting sheet of the composite sheet of one aspect of the present invention shares the task of a peeling sheet to prevent dust and the like from adhering to the surface of the resin film forming sheet, or a cutting sheet to protect the surface of the resin film forming sheet in the cutting step, etc. .

The supporting sheet used in the present invention preferably has a resin film.

Examples of the resin film include low-density polyethylene (LDPE) Film or polyethylene film such as linear low density polyethylene (LLDPE) film, ethylene-propylene copolymer film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film , Vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene·vinyl acetate copolymer film, ionomer Material resin film, ethylene‧(meth)acrylic acid copolymer film, ethylene‧(meth)acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc.

The support sheet used as one aspect of the present invention may be a single-layer film composed of one type of resin film, or a laminated film composed of two or more types of resin films laminated.

In addition, the above-mentioned resin film may also be a cross-linked film.

In addition, it is also possible to use a coloring resin film, a printing application, and the like.

In addition, the resin film may be formed into a thin sheet by extruding a thermoplastic resin, or may be stretched, or may be formed into a thin sheet by thinning and curing the curable resin by a specific method.

Among these resin films, a resin film containing a polypropylene film is preferred from the viewpoint that it has excellent heat resistance and has moderate flexibility and expandability, and therefore it is easy to maintain pick-up suitability.

In addition, as the structure of the support sheet having a resin film containing a polypropylene film, a single-layer structure composed of only a polypropylene film may be used, or a multi-layer structure composed of a polypropylene film and other resin films may also be used.

When the sheet for forming a resin film is thermosetting, the resin film constituting the support sheet has heat resistance, so that the support sheet is prevented from being damaged by heat, and the disadvantages caused by the manufacturing process of the semiconductor device can be suppressed.

When the support sheet is used as a peeling sheet to prevent dust and the like from adhering to the surface of the resin film forming sheet, the support sheet can be easily peeled off from the resin film forming sheet during the attaching to the silicon wafer or the dicing step. A resin film is preferred.

In addition, as the support sheet, a resin film that has been subjected to a peeling treatment on the surface of the above-mentioned resin film can also be used.

As a method of the peeling treatment, a method of providing a peeling film formed of a release agent on the surface of the above-mentioned resin film is preferable.

The release agent includes, for example, release of resins selected from acrylic resins, alkyd resins, silicone resins, fluorine resins, unsaturated polyester resins, polyolefin resins, wax resins, etc.剂 etc.

When the support sheet is used as a dicing sheet for protecting the surface of the resin film forming sheet in the cutting step, etc., the support sheet is preferably an adhesive sheet having an adhesive layer formed of an adhesive on the above-mentioned resin film.

As the adhesive resin contained in the adhesive, when focusing on the structure of the adhesive resin, for example, acrylic resins, polyurethane resins, rubber resins, polysiloxane resins, vinyl ether resins, etc. can be cited. In the case of function, for example, an energy ray curable resin etc. can be mentioned.

In one aspect of the present invention, from the viewpoint of setting a good pick-up property, an adhesive containing an energy ray-curable resin is preferable.

In addition, when an adhesive layer formed of an adhesive containing energy ray-curable resin is placed on the resin film, the adhesive layer can also be an adhesive layer that is cured by irradiation with energy rays, or it can be uncured before being irradiated with energy rays. The adhesive layer. In addition, when using a support sheet with an uncured adhesive layer before the energy ray irradiation, it is also possible to irradiate the energy ray before the pickup step to harden the adhesive layer.

As the thickness of the support sheet, although it can be appropriately selected depending on the application, it is preferably 10 to 500 μm, preferably 20 to 350 μm, and more preferably 30 to 200 μm.

In addition, the thickness of the above-mentioned support sheet is not only the thickness of the resin film constituting the support sheet, but also includes the thickness of the adhesive layer or the release film when there is an adhesive layer or a release film.

<Fixture Adhesive Layer>

The jig adhesive layer can be formed of a double-sided adhesive sheet with a base material (core material) or an adhesive composition containing an adhesive.

As the base material (core material), a resin film or a polypropylene film that can be used as the above-mentioned support sheet is preferable.

In addition, examples of the above-mentioned adhesive include acrylic resins, polyurethane resins, rubber resins, polysiloxane resins, vinyl ether resins, and the like.

The thickness of the clamp adhesive layer is preferably 1 to 80 μm, preferably 5 to 60 μm, and more preferably 10 to 40 μm.

〔Method of regenerating silicon wafer〕

The present invention also provides a method for regenerating the silicon wafer by directly attaching the laminated body of the surface (α) of the resin film forming sheet of the present invention to the silicon wafer and processing the resin film forming sheet.

The silicon wafer regeneration method of the present invention has the following steps (1) to (2).

Step (1): a step of attaching the substrate and the adhesive layer of the adhesive sheet of the adhesive layer on the surface (β) of the resin film forming sheet of the laminate,

Step (2): In the stretching step (1), the adhesive sheet is attached to the surface (β ) of the resin film forming sheet, and the resin film forming sheet attached to the silicon wafer is processed again的步。 The steps.

The method for regenerating the silicon wafer of the present invention is to attach the resin film forming sheet of the present invention to the silicon wafer, and when there is a need for reprocessing, the silicon wafer is not damaged and the formation of the attached resin film is suppressed A part of the sheet is attached to the silicon wafer and the remaining side can be reprocessed, using the properties of the sheet for forming a resin film of the present invention.

In addition, the method for regenerating a silicon wafer according to one aspect of the present invention is not only applicable to the laminated body on the silicon wafer immediately adjacent to the surface (α) on which the resin film forming sheet of the present invention is directly attached, but also applicable It is a laminate in a state where the adhesion between the silicon wafer and the resin film forming sheet has been improved after about 24 hours from the attachment.

Hereinafter, the steps (1) and (2) of the silicon wafer regeneration method of the present invention will be described.

<Step (1)>

Step (1) is a step of attaching the adhesive layer of the adhesive sheet having the substrate and the adhesive layer on the surface (β) of the resin film forming sheet of the laminate.

As the adhesive sheet used in this step, it has a substrate and an adhesive layer.

The base resin film is preferable, and the resin film exemplified in the item of the support sheet mentioned above can be cited.

As the adhesive layer requirement (III), it has structural units derived from butyl acrylate and acrylic acid, and contains 100 parts by mass of propylene resin with a mass average molecular weight of 600,000 to 1,000,000 and a crosslinking agent of 0.01~ An adhesive layer with a thickness of 10-50 μm formed by 10 parts by mass of the adhesive is preferable.

However, in one aspect of the present invention, in addition to the above-mentioned adhesive, if the adhesive force ( β 1) of the surface (β ) can be formed into an adhesive of the adhesive layer within the above-mentioned range, it can be used.

Although the shape of the adhesive sheet is not particularly limited, from the viewpoint of the operability of the following step (2), it is the same shape as the resin film forming sheet, or an adhesive sheet having a larger shape than the resin film forming sheet good.

As the method of attaching the surface ( β ) to the adhesive layer of the adhesive sheet in this step, either mechanical attachment or manual attachment can be used.

In addition, when the surface (α) of the resin film forming sheet of the composite sheet of one aspect of the present invention is attached to the silicon wafer, and the surface ( β ) side has been laminated to form a dicing sheet support sheet, The cut sheet can also be used as the adhesive sheet in this step.

<Step (2)>

In step (2), in the stretching step (1), the adhesive sheet is attached to the surface (β ) of the resin film forming sheet, and the resin film forming sheet attached to the silicon wafer is processed.的步。 The steps.

In this step, the resin film forming sheet of the present invention is used. Since the adhesive force (α 1) and ( β 1) of the resin film forming sheet are within the above range, the stretching step (1) is applied to the surface ( β ) Adhesive sheets are attached, and the resin film forming sheets are also dragged along. The aforementioned resin film forming sheets can be reprocessed from the silicon wafer.

There is no particular limitation as to the speed and angle when the adhesive sheet is stretched, and can be set appropriately.

In addition, although the mechanically stretched adhesive sheet can also be used in this step, from the viewpoint of operability, it is preferable to manually stretch the adhesive sheet, and to reprocess the aforementioned resin film forming sheet from a silicon wafer.

In addition, after removing the resin film forming sheet in this step, if necessary, the surface of the silicon wafer can be cleaned with an organic solvent such as ethanol.

Through the above steps, it is possible to regenerate the silicon wafer once attached with the resin film forming sheet.

[Example]

The method for measuring the mass average molecular weight (Mw) or number average molecular weight (Mn) of each component used in Production Examples 1 to 8 is as follows.

<Mass average molecular weight (Mw), number average molecular weight (Mn)>

The measurement was performed with a gel permeation chromatography device (manufactured by Tosoh Co., Ltd., trade name "HLC-8220GPC") under the following conditions, and the measured value in terms of standard polystyrene was used.

(Measurement conditions)

Column: "TSK guard column HXL-H", "TSK gel GMHXL(×2)", "TSK gel G2000HXL" (manufactured by Tosoh Corporation)

Column temperature: 40℃

Developing solvent: tetrahydrofuran

Flow rate: 1.0mL/min

Manufacturing examples 1~8

(Preparation of solution of composition for resin film formation)

After blending each component of the type and blending amount shown in Table 1 to prepare resin film forming compositions (1) to (8) (referred to as "compositions (1) to (8)" in Table 1), It was further diluted with methyl ethyl ketone to prepare a solution of a composition having a solid content concentration of 61% by mass.

In addition, the blending amount of each component in Table 1 is relative to the total amount of each composition (the total blending amount of components (A) ~ (G)) 100% by mass (unit: mass% (effective component ratio) )). In addition, the details of each component described in Table 1 are as follows.

<Polymer component (A)>

(A-1): Propylene copolymer obtained by copolymerizing methacrylate (MA) and 2-hydroxyethyl acrylate (HEA) (composition ratio: MA/HEA=95/5 (mass%), Mw=80 ten thousand).

(A-2): Propylene copolymer obtained by copolymerization of n-butyl acrylate (BA), ethacrylate (EA), acrylonitrile (AN) and glycidyl methyl acrylate (GMA) (composition ratio: BA/EA/AN/GMA=39/29/29/3 (mass%), Mw=800,000).

(A-3): Propylene copolymer obtained by copolymerization of n-butyl acrylate (BA), methacrylate (MA), glycidyl methyl acrylate (GMA) and 2-hydroxyethyl acrylate (HEA) Material (composition ratio: BA/MA/GMA/HEA=55/10/20/15 (mass%), Mw=800,000).

(A-4): Propylene copolymer obtained by copolymerizing n-butyl acrylate (BA), ethacrylate (EA) and glycidyl methyl acrylate (GMA) (composition ratio: BA/EA/GMA= 53/44/3 (mass%), Mw=800,000).

<Sclerosing component (B)>

(B-1): Cresol novolac type epoxy resin with addition of acryl group (manufactured by Nippon Kayaku Co., Ltd., trade name "CNA-147", equivalent to the epoxy compound of the aforementioned component (B11)).

(B-2): Biphenylarane type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name "NC-3000H", equivalent to the epoxy compound of the aforementioned component (B11)).

(B-3): Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "jER828", equivalent to the epoxy compound of the aforementioned component (B11)).

(B-4): Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "jER1055", which corresponds to the epoxy compound of the aforementioned component (B11)).

(B-5): Dicyclopentadiene epoxy resin (manufactured by DIC Co., Ltd., trade name "EPICLON HP-7200HH", equivalent to the epoxy compound of the aforementioned component (B11)).

(B-6): Biphenylarane-type phenol resin (manufactured by Minghe Chemical Co., Ltd., trade name "MEH-7851-H", equivalent to the thermosetting agent of the aforementioned component (B12)).

(B-7): Dicyanodiamide (manufactured by ADEKA Co., Ltd., trade name "ADEKA HARDENER 3636AS", equivalent to the thermosetting agent of the aforementioned component (B12)).

(B-8): Imidazole-based hardening accelerator (manufactured by Shikoku Chemical Industry Co., Ltd., trade name "Curezol 2PHZ", equivalent to the hardening accelerator of the aforementioned component (B13)).

<Inorganic Filler (C)>

(C-1): Silica filler (average particle size=50nm).

(C-2): Silica filler (average particle size=500nm).

<Colorant (D)>

(D-1): Carbon black (average particle size=28nm).

<Silane Coupling Agent (E)>

(E-1): Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-403").

<Leveling agent (F)>

(F-1): Polysiloxane-based leveling agent (manufactured by Momentif Properties Japan Co., Ltd., trade name "XF 42-334").

<General additives (G)>

(G-1): Isocyanate-based crosslinking agent (manufactured by TOYOCHEM Co., Ltd., trade name "BHS 8515").

Example 1

The first support sheet (manufactured by Lintec Co., Ltd., trade name "SP-PET 3811", thickness: 38μm) of the first support sheet composed of a resin film that has been peeled off is coated on the peeling surface prepared by manufacturing example 2 The solution of the composition (2) for forming a resin film is dried to form a coating film (α').

Then, the solution of the resin film formation composition (1) prepared in Manufacturing Example 1 was applied to the release treatment surface of the second support sheet which was the same as the first support sheet, and dried to form a coating film ( β ') .

After that, the coating films (α') and ( β ') formed on the two support sheets were bonded together, and dried at 120°C for 2 minutes to form a resin film forming sheet with a total thickness of 25μm. To prepare a composite sheet for forming a resin film composed of the first supporting sheet/resin film forming sheet/the second supporting sheet.

In addition, in the composite sheet, the surface of the resin film forming sheet exposed when the first support sheet is removed is the "surface (α)" on the silicon wafer attaching side, and the second support sheet is exposed when the second support sheet is removed. The surface of the resin film forming sheet is "surface ( β )".

Example 2

In Example 1, instead of "the solution of the resin film formation composition (2) prepared in the production example 2", the same was made except that the "solution of the resin film formation composition (3) prepared in the production example 3" was used. Composite sheet for resin film formation.

Example 3

In Example 1, instead of "the solution of the resin film formation composition (2) prepared in the production example 2", the same was made except that the "solution of the resin film formation composition (4) prepared in the production example 4" was used. Composite sheet for resin film formation.

Example 4

In Example 1, the "solution of the resin film forming composition (2) prepared in Production Example 2" was replaced in the same manner, except that the "solution of the resin film forming composition (5) prepared in Production Example 5" was used. A composite sheet for forming a resin film was produced.

Example 5

The first support sheet (manufactured by Lindeco, trade name "SP-PET3811", thickness: 38μm) composed of a resin film that has been peeled off is coated on the peeling surface prepared by manufacturing example 6 After the solution of the resin film forming composition (6) forms a coating film, it is dried at 120°C for 2 minutes to form a resin film forming sheet having a thickness of 25 μm.

Then, the surface of the formed resin film forming sheet and the peeling treatment surface of the second support sheet, which is the same as the first support sheet, are bonded to produce a first support sheet/resin film forming sheet/second A composite sheet for forming a resin film composed of the support sheet.

Comparative example 1

In Example 5, in place of the "solution of the resin film formation composition (6) prepared in Production Example 6", the same was used except that the "solution of the resin film formation composition (3) prepared in Production Example 3" was used A composite sheet for forming a resin film was produced.

Comparative example 2

In Example 5, in place of the "solution of the resin film forming composition (6) prepared in Production Example 6", the same was used except that the "solution of the resin film forming composition (7) prepared in Production Example 7" was used. A composite sheet for forming a resin film was produced.

Comparative example 3

In Example 5, in place of the "solution of the resin film formation composition (6) prepared in Production Example 6", the same was used except that the "solution of the resin film formation composition (8) prepared in Production Example 8" was used. A composite sheet for forming a resin film was produced.

Using the composite sheets produced in the examples and comparative examples, the following physical property values were measured and evaluated as follows. Table 2 shows these results.

<Requirement (I): Measurement of the surface roughness (Ra) of the surface (α) of the resin film forming sheet>

The first supporting sheet of the composite sheets produced in the examples and comparative examples was removed, and a contact surface roughness meter (manufactured by Mitutoyo Co., Ltd., The product name is "SURFTEST SV-3000"), the cut-off value λ c is set to 0.8 mm, and the evaluation length Ln is set to 4 mm, and it is measured in accordance with JIS B0601:2001.

<Requirement (II): For the surface of the resin film forming sheet of the silicon wafer (α) Measurement of adhesion>

Remove the first support sheet of the composite sheet produced in the Examples and Comparative Examples, and use a tape placement machine (manufactured by Lindeco Co., Ltd., trade name "Adwill RAD-3600 F/12") at 70°C Attach the exposed surface (α) of the resin film forming sheet and the polished surface of the #2000 polished silicon wafer (diameter: 200mm, thickness: 600μm) while heating.

Then, remove the second support sheet of the composite sheet, and use a 2kg roller to paste the exposed surface ( β ) of the resin film forming sheet on a hot plate heated at 70°C and a commercially available adhesive sheet used as a laminating tape (Lintec Co., Ltd., trade name "PET 50 (A) PAT1", width: 25mm) after the adhesive layer, and then stand for 24 hours at 23°C and 50%RH (relative humidity).

After standing still, a universal testing machine (manufactured by Shimadzu Corporation, trade name "Autograph AG-IS") was used to conduct a tensile test under the conditions of a peeling angle of 180° and a peeling speed of 0.3m/min. The load when the protective film forming sheet and the mounting tape are peeled off the surface. The value of this load is set as the adhesive force of the silicon wafer to the surface (α) of the resin film forming sheet.

In addition, when the tensile test of the above-mentioned commercially available adhesive sheet used as the laminating tape was performed, the protective film formation sheet and the adhesive layer of the adhesive sheet did not peel off at the interface, and there was no peeling on the protective film formation sheet The adhesive strength of the interface with the silicon wafer can be stably peeled off.

<Requirement (III): Measurement of the adhesive force on the surface (β ) of the sheet for forming the adhesive layer resin film of the adhesive sheet>

Use a rubber roller at room temperature (25°C) to attach a double-sided adhesive tape for fixing the resin film forming sheet on the silicon wafer (Lintec Co., Ltd., trade name "TL-4100S-50"). In addition, the double-sided adhesive tape was selected to be able to sufficiently fix the protective film forming sheet during the tensile test.

Then, the adhesive surface of the double-sided adhesive tape and the first supporting sheet of the composite sheet produced in the Examples and Comparative Examples were removed, and a tape placement machine (manufactured by Lindke (Stock), trade name "Adwill RAD-") was used. 3600 F/12”) Attach the exposed surface (α) of the resin film forming sheet at room temperature.

After that, the second support sheet of the composite sheet was removed, and the exposed surface ( β ) of the resin film forming sheet and the adhesive layer of the later-mentioned adhesive sheet were pasted at 23°C using a 2kg roller, and 23°C, 50°C Let stand for 20 minutes in an environment of %RH (relative humidity).

After standing, a universal testing machine (manufactured by Shimadzu Corporation, trade name "Autograph AG-IS") was used to perform a tensile test under the conditions of a peeling angle of 180° and a peeling speed of 0.3m/min to measure the formation of the protective film The load when peeling the adhesive sheet with the surface ( β) of the sheet. The value of this load is set as the adhesive force of the adhesive sheet to the surface (β ) of the resin film forming sheet of the adhesive layer.

(Details of the adhesive sheet attached to the surface ( β ))

Used for corona-treated ethylene-methyl methacrylate copolymer (composition ratio: ethylene/methyl methacrylate=90/10 (mass Compared with)), the corona-treated surface of the resin film composed of the resin film has an adhesive sheet with a 20μm thick adhesive layer formed of the following adhesive composition.

Adhesive composition: 100 parts by mass of propylene copolymer (BA/AA=90/10 (mass ratio), Mw=700,000) obtained by copolybutyl acrylate (BA) and acrylic acid (AA), blended 5 parts by mass of toluene diisocyanate-based crosslinking agent (trade name "Coronate L", manufactured by NIPPON POLYURETHANE INDUSTRY).

<Measurement of storage elastic modulus of sheet for resin film formation at 23°C>

After multiple lamination of the resin film forming sheet constituted by removing the two supporting sheets of the composite sheets produced in the Examples and Comparative Examples, a test sample with a thickness of 0.18 mm, a width of 4.5 mm, and a length of 20.0 mm was produced.

For this test sample, a dynamic viscoelasticity measuring device (manufactured by TA instruments, trade name "DMA Q800") was used to measure the storage of the resin film forming sheet at 23°C in a tensile mode at a frequency of 11 Hz, 23°C, and an atmospheric environment. Elastic modulus (unit: GPa).

<Measurement of the contact angle of water on the surface (β ) of the resin film forming sheet>

The second supporting sheet of the composite sheet produced in the Examples and Comparative Examples was removed, and 10 ml of distilled water was dropped on the surface (β ) of the exposed resin film forming sheet, and then it was allowed to stand for 10 minutes.

After standing still, use an automatic contact angle measuring device (manufactured by KRUSS, trade name "DSA 100S") to measure the angle formed by the surface (β ) and the water droplet, and set this angle as the "contact angle of water to the surface (β )" .

<Evaluation (1): Reworkability of sheet for forming resin film>

The first supporting sheet of the composite sheet produced in the examples and comparative examples was removed, and a tape placement machine (manufactured by Lindeke (stock), trade name "Adwill RAD-3600 F/12") was used, with a side of 70 Attach the exposed surface (α) of the resin film forming sheet and the polished surface of the #2000 polished silicon wafer (diameter: 200mm, thickness: 600μm) while heating at 23°C, 50%RH( Let stand for 24 hours in an environment with relative humidity.

After standing, remove the second support sheet of the composite sheet, and paste the exposed surface ( β ) of the resin film forming sheet and a commercially available general dicing tape (Lindeke (Stock) at room temperature (25°C) ) Manufactured with the trade name "Adwill D-510T", the above-mentioned requirement (III) has the surface of the adhesive layer of the adhesive layer formed by the specific adhesive, and let it stand for 20 minutes.

After that, manually stretch the general-purpose dicing tape. When reprocessing the resin film forming sheet from the silicon wafer, observe whether it can be reprocessed and whether there is any residue on the surface of the reprocessed silicon wafer. The reworkability of the resin film forming sheet was evaluated based on the following criteria.

A: The protective film forming sheet can be completely peeled from the silicon wafer. No visible residues of the protective film formation sheet were observed on the silicon wafer after reprocessing.

B: The protective film formation sheet can be peeled from the silicon wafer. Although some residues of the protective film forming sheet were observed on the silicon wafer after reprocessing, it can be completely removed if wiped with ethanol.

C: The silicon wafer was damaged during regeneration, or the silicon wafer can be reprocessed even if the silicon wafer is not damaged. However, the reprocessed silicon wafer confirmed the residue of the protective film forming sheet to the extent that it is difficult to wipe with ethanol.

<Evaluation (2): Adhesion of the end of the resin film forming sheet>

The first supporting sheet of the composite sheet produced in the examples and comparative examples was removed, and a tape placement machine (manufactured by Lindeke (stock), trade name "Adwill RAD-3600 F/12") was used, with a side of 70 Attach the exposed surface (α) of the resin film forming sheet and the polished surface of the #2000 polished silicon wafer (diameter: 200mm, thickness: 600μm) while heating at ℃, and then remove the second support sheet. Attach a silicon wafer and a sheet for forming a resin film.

After that, visually observe the end of the silicon wafer to which the resin film forming sheet is attached, and evaluate the end adhesion of the resin film forming sheet based on the following criteria based on the number of curls or deletions of 0.5 mm or more .

A: The number of curls or deletions above 0.5mm is 0.

B: The number of crimps or deletions above 0.5mm is 1~4.

C: The number of crimps or deletions of 0.5 mm or more is 5 or more.

Table 2 shows that the resin film forming sheets produced in Examples 1 to 5, which are one aspect of the present invention, have excellent results in both reworkability and end adhesion.

On the other hand, the resin film forming sheet of Comparative Example 1 has a low surface ( β ) adhesion force ( β 1) value, so when the adhesive sheet is used to reprocess the resin film forming sheet, the resin film is formed A part of the thin film remains on the silicon wafer as a result of deterioration in reworkability.

In addition, the resin film forming sheet of Comparative Example 3 has a high adhesive force (α 1) value on the surface (α), so the silicon wafer is damaged during the operation of using the resin film forming sheet to reprocess the adhesive sheet. As a result of deterioration of reworkability.

In addition, although the sheet system for forming a resin film of Comparative Example 2 has good reworkability, the end of the silicon wafer after attachment is a result of deterioration in adhesion.

〔Possibility of industrial use〕

The resin film forming sheet of one aspect of the present invention is suitable as a material for forming a protective film for protecting the back surface of a semiconductor chip, or as a material for forming an adhesive film that can be attached to a die pad or other parts.

Claims (6)

A sheet for forming a resin film, which is a sheet for forming a resin film for attaching to a silicon wafer and forming a resin film on the silicon wafer, and satisfies the following requirements (I) to (III), and the foregoing The contact angle of the surface (β ) of the resin film forming sheet to water is 70~110°, Requirement (I): The surface roughness (Ra) of the surface (α) of the aforementioned resin film forming sheet on the side where the silicon wafer is attached is 50 nm or less, Requirement (II): The adhesion force (α 1) of the surface (α) of the aforementioned resin film forming sheet to the silicon wafer is 1.0~7.0N/25mm, Requirement (III): The surface ( β ) of the aforementioned resin film forming sheet is the opposite side of the silicon wafer attaching side to the adhesive layer of the adhesive layer formed by the adhesive with the adhesive layer ( β 1) is 4.0N/25mm or more, The aforementioned adhesive contains 100 parts by mass of acrylic resin having structural units derived from butyl acrylate and acrylic acid, a mass average molecular weight of 600,000 to 1 million, and 0.01 to 10 parts by mass of a crosslinking agent, The aforementioned adhesive sheet has an adhesive layer with a thickness of 10-50 μm. For example, the sheet for forming a resin film in the first item of the scope of patent application, wherein the storage modulus of elasticity at 23°C is 0.10-20GPa. Such as the sheet for forming a resin film in the first or second patent application, which is used to form a protective film on a silicon wafer. A composite sheet for forming a resin film, which has a structure in which the resin film forming sheet according to any one of items 1 to 3 in the scope of the patent application is laminated on a support sheet. The composite sheet for forming a resin film according to claim 4, wherein the sheet for forming a resin film has a structure sandwiched by two supporting sheets. A method for regenerating a silicon wafer, which is to directly attach a laminate of the surface (α) of the resin film forming sheet as in any one of the scope of patent application items 1 to 3 on the silicon wafer, and then process the resin A method for regenerating silicon wafers with thin films for film formation, and it has the following steps (1)~(2), Step (1): a step of attaching the adhesive layer of the adhesive sheet having the base material and the adhesive layer on the surface (β) of the resin film forming sheet of the laminate, Step (2): Stretching the adhesive sheet attached to the surface (β) of the resin film forming sheet in the step (1), and then processing the resin film attached to the silicon wafer The step of thin slices.

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