CN118027840A - Composite sheet for forming protective film - Google Patents

Composite sheet for forming protective film Download PDF

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Publication number
CN118027840A
CN118027840A CN202410233893.8A CN202410233893A CN118027840A CN 118027840 A CN118027840 A CN 118027840A CN 202410233893 A CN202410233893 A CN 202410233893A CN 118027840 A CN118027840 A CN 118027840A
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CN
China
Prior art keywords
protective film
forming
film
meth
acrylate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202410233893.8A
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Chinese (zh)
Inventor
米山裕之
稻男洋一
小桥力也
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Lintec Corp
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Lintec Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
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Publication of CN118027840A publication Critical patent/CN118027840A/en
Pending legal-status Critical Current

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    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09JADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00Adhesives in the form of films or foils
    • C09J7/20Adhesives in the form of films or foils characterised by their carriers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/06Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/16Layered products comprising a layer of synthetic resin specially treated, e.g. irradiated
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/18Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B33/00Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02Physical, chemical or physicochemical properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04Interconnection of layers
    • B32B7/12Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09JADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J201/00Adhesives based on unspecified macromolecular compounds
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2305/00Condition, form or state of the layers or laminate
    • B32B2305/72Cured, e.g. vulcanised, cross-linked
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2310/00Treatment by energy or chemical effects
    • B32B2310/08Treatment by energy or chemical effects by wave energy or particle radiation

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Adhesive Tapes (AREA)
  • Dicing (AREA)
  • Laminated Bodies (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Physical Vapour Deposition (AREA)

Abstract

The present invention relates to a composite sheet for forming a protective film, comprising a support sheet and an energy-ray-curable film for forming a protective film on the support sheet, wherein when the protective film is formed by irradiating the protective film with energy rays, the adhesive force between the protective film and the support sheet is 50 to 1500mN/25mm.

Description

Composite sheet for forming protective film
The present application is a divisional application of chinese patent application having application number 201780020726.3, application date 2017, 4/25, and the name "composite sheet for forming protective film", and the present application claims priority from japanese patent application publication number 2016-092014 filed in japan at 4/28 of 2016.
Technical Field
The present invention relates to a composite sheet for forming a protective film.
The present application claims priority based on japanese patent application publication No. 2016-092014, which was filed in japan, 4/28 of 2016, and the contents thereof are hereby incorporated.
Background
In recent years, a semiconductor device using a so-called flip-chip (face down) mounting method has been manufactured. In the flip-chip method, a semiconductor chip having electrodes such as bumps on a circuit surface, the electrodes being bonded to a substrate, is used. Therefore, the back surface of the semiconductor chip opposite to the circuit surface may be exposed.
A resin film containing an organic material as a protective film is formed on the back surface of the exposed semiconductor chip, and the resin film may be incorporated into a semiconductor device as a semiconductor chip with a protective film. To prevent cracks from being generated on the semiconductor chip after the dicing process or the packaging, a protective film is used.
For forming such a protective film, for example, a protective film forming composite sheet including a protective film forming film for forming a protective film on a support sheet is used. In the composite sheet for forming a protective film, the protective film can be formed by curing, and the support sheet can be used as a dicing sheet, so that the composite sheet for forming a protective film, in which the protective film forming film and the dicing sheet are integrated, can be produced.
As such a composite sheet for forming a protective film, for example, a composite sheet for forming a protective film having a thermosetting protective film which is cured by heating to form a protective film has been mainly used. In this case, for example, a composite sheet for forming a protective film is attached to the back surface (surface opposite to the electrode forming surface) of the semiconductor wafer by a thermosetting film for forming a protective film, and then the film for forming a protective film is cured by heating, whereby the semiconductor wafer and the protective film are divided together by dicing to obtain semiconductor chips. Then, the semiconductor chip is separated from the support sheet and picked up while maintaining the state where the protective film is attached. In addition, curing and cutting of the protective film forming film may be performed in the reverse order of the above.
However, since the heat curing of the thermosetting protective film-forming film generally takes a long time of about several hours, it is desired to shorten the curing time. In this regard, a film for forming a protective film, which can be cured by irradiation with energy rays such as ultraviolet rays, has been studied for forming a protective film. For example, an energy ray-curable protective film formed on a release film (see patent document 1) and an energy ray-curable core protective film capable of forming a protective film having high hardness and excellent adhesion to a semiconductor chip (see patent document 2) have been disclosed.
However, it is uncertain whether the adhesion of the energy ray-curable protective film disclosed in patent document 1 to the support sheet is suitable. Further, as for the energy ray-curable core plate protective film disclosed in patent document 2, although it is disclosed that it is formed on the support sheet, it is uncertain whether or not the adhesion to the support sheet is suitable. As described above, the pickup suitability of the protective film forming films disclosed in patent documents 1 and 2 is not clear.
Prior art literature
Patent literature
Patent document 1: japanese patent No. 5144433
Patent document 2: japanese patent laid-open No. 2010-031183
Disclosure of Invention
Technical problem to be solved by the invention
The invention provides a composite sheet for forming a protective film, which has an energy ray-curable film for forming a protective film, can form a protective film on the back surface of a semiconductor wafer or a semiconductor chip, and has good pick-up suitability.
Technical means for solving the technical problems
The invention provides a composite sheet for forming a protective film, which comprises a support sheet and an energy ray-curable protective film forming film on the support sheet, wherein when the protective film forming film is irradiated with energy rays to form the protective film, the adhesive force between the protective film and the support sheet is 50-1500 mN/25mm.
In the composite sheet for forming a protective film of the present invention, the adhesive force between the film for forming a protective film and the support sheet may be 80mN/25mm or more.
In the composite sheet for forming a protective film of the present invention, the layer of the support sheet in direct contact with the film for forming a protective film may be non-energy ray curable.
The composite sheet for forming a protective film of the present invention may further comprise a pressure-sensitive adhesive layer for a jig on the film for forming a protective film or the support sheet.
Effects of the invention
By using the composite sheet for forming a protective film of the present invention, a protective film can be formed on the back surface of a semiconductor wafer or a semiconductor chip, and the semiconductor chip having the protective film can be satisfactorily peeled off from the supporting sheet and picked up.
Drawings
Fig. 1 is a cross-sectional view schematically showing an embodiment of a composite sheet for forming a protective film according to the present invention.
Fig. 2 is a cross-sectional view schematically showing another embodiment of the composite sheet for forming a protective film of the present invention.
Fig. 3 is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.
Fig. 4 is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.
Fig. 5 is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.
Description of the reference numerals
1A, 1B, 1C, 1D, 1E: a protective film-forming composite sheet; 10: a support sheet; 10a: the surface of the support sheet; 11: a substrate; 11a: a surface of the substrate; 12: an adhesive layer; 12a: the surface of the adhesive layer; 13. 23: a protective film forming film; 13a, 23a: a surface of the protective film forming film; 15: stripping the film; 16: an adhesive layer for jigs; 16a: the surface of the adhesive layer for jigs.
Detailed Description
Composite sheet for forming protective film
The composite sheet for forming a protective film of the present invention comprises a support sheet, and an energy-ray-curable protective film forming film provided on the support sheet, wherein when the protective film forming film is irradiated with energy rays to form a protective film, the adhesive force between the protective film and the support sheet is 50 to 1500mN/25mm.
In the present invention, the "protective film forming film" refers to a film before curing, and the "protective film" refers to a film obtained by curing a protective film forming film.
The protective film-forming film is cured by irradiation with energy rays, and becomes a protective film. The protective film is used to protect the back surface (surface opposite to the electrode forming surface) of the semiconductor wafer or the semiconductor chip. The protective film forming film is soft and can be easily attached to an object to be attached. Further, the composite sheet for forming a protective film of the present invention has excellent pickup suitability by setting the adhesion between the protective film and the supporting sheet to 50 to 1500mN/25mm, and for example, can pick up a target semiconductor chip with high selectivity, thereby suppressing cracking and chipping of the semiconductor chip at this time.
In the composite sheet for forming a protective film of the present invention, the protective film can be formed by curing the protective film-forming film in a shorter time than the conventional composite sheet for forming a protective film including a thermosetting protective film by setting the protective film-forming film to be energy ray-curable.
In the present invention, the "energy ray" refers to a ray having energy in an electromagnetic wave or a charged particle beam, and examples thereof include ultraviolet rays, radiation rays, and electron beams.
The ultraviolet rays can be irradiated by using, for example, a high-pressure mercury lamp, a fusion H lamp (fusion H lamp), a xenon lamp, a black light lamp, an LED lamp, or the like as an ultraviolet source. The electron beam can irradiate an electron beam generated by an electron beam accelerator or the like.
In the present invention, "energy ray curability" refers to a property that is cured by irradiation with energy rays, and "non-energy ray curability" refers to a property that is not cured even when energy rays are irradiated.
The thickness of the semiconductor wafer or semiconductor chip to be used as the composite sheet for forming a protective film of the present invention is not particularly limited, and is preferably 30 to 1000 μm, more preferably 100 to 300 μm, since the effect of the present invention can be more remarkably obtained.
The constitution of the present invention will be described in detail below.
Support sheet for very good
The support sheet may be formed of one layer (single layer) or may be formed of a plurality of layers including two or more layers. When the support sheet is composed of a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited as long as the effect of the present invention is not impaired.
In the present specification, not limited to the case of the support sheet, "the plurality of layers may be the same as or different from each other" means "all the layers may be the same as or different from each other, or only a part of the layers may be the same as each other", and "the plurality of layers are different from each other" means "at least one of the constituent materials and thicknesses of the respective layers is different from each other".
Examples of the preferable support sheet include a support sheet in which an adhesive layer is laminated in direct contact with a substrate, a support sheet in which an adhesive layer is laminated on a substrate via an intermediate layer, and a support sheet composed only of a substrate.
Hereinafter, an example of the composite sheet for forming a protective film according to the present invention will be described with reference to the drawings, according to the type of the support sheet. In order to facilitate understanding of the features of the present invention, important parts of the drawings used in the following description may be enlarged and displayed, and the dimensional ratios of the constituent elements and the like are not necessarily the same as those of the actual ones.
Fig. 1 is a cross-sectional view schematically showing an embodiment of a composite sheet for forming a protective film according to the present invention.
The protective film forming composite sheet 1A shown here includes an adhesive layer 12 on a base material 11, and a protective film forming film 13 on the adhesive layer 12. The support sheet 10 is a laminate of a base material 11 and an adhesive layer 12, in other words, the composite sheet 1A for forming a protective film has a structure in which a film 13 for forming a protective film is laminated on a surface 10a of one side of the support sheet 10. The protective film forming composite sheet 1A further includes a release film 15 on the protective film forming film 13.
In the composite sheet 1A for forming a protective film, an adhesive layer 12 is laminated on a surface 11A of one side of a base material 11, a film 13 for forming a protective film is laminated on the entire surface 12a of one side of the adhesive layer 12, a pressure-sensitive adhesive layer 16 for a jig is laminated on a part of the surface 13a of the film 13 for forming a protective film, that is, a region near a peripheral edge portion, and a release film 15 is laminated on a region of the surface 13a of the film 13 for forming a protective film, which is not laminated with the pressure-sensitive adhesive layer 16 for a jig, and a surface 16a (upper surface and side surface) of the pressure-sensitive adhesive layer 16 for a jig.
In the protective film-forming composite sheet 1A, the adhesion between the cured protective film-forming film 13 (i.e., protective film) and the support sheet 10, in other words, the adhesion between the protective film and the adhesive layer 12 is 50 to 1500mN/25mm.
The pressure-sensitive adhesive layer 16 for jigs may have a single-layer structure containing a pressure-sensitive adhesive component, or may have a multilayer structure in which layers containing a pressure-sensitive adhesive component are laminated on both surfaces of a sheet as a core material.
The protective film forming composite sheet 1A shown in fig. 1 is used in the following manner: with the release film 15 removed, the back surface of the semiconductor wafer (not shown) is attached to the front surface 13a of the protective film forming film 13, and the upper surface of the front surface 16a of the jig adhesive layer 16 is further attached to a jig such as a ring frame.
Fig. 2 is a cross-sectional view schematically showing another embodiment of the composite sheet for forming a protective film of the present invention. In the drawings subsequent to fig. 2, the same components as those shown in the already described drawings are denoted by the same reference numerals as those in the already described drawings, and detailed description thereof is omitted.
The protective film forming composite sheet 1B shown here is the same as the protective film forming composite sheet 1A shown in fig. 1 except that the jig adhesive layer 16 is not provided. That is, in the composite sheet 1B for forming a protective film, the adhesive layer 12 is laminated on the surface 11a of one side of the base material 11, the film 13 for forming a protective film is laminated on the entire surface 12a of the adhesive layer 12, and the release film 15 is laminated on the entire surface 13a of the film 13 for forming a protective film.
The protective film forming composite sheet 1B shown in fig. 2 is used in the following manner: with the release film 15 removed, the rear surface of the semiconductor wafer (not shown) is attached to a partial region on the central side of the front surface 13a of the protective film forming film 13, and the region near the peripheral edge is further attached to a jig such as a ring frame.
Fig. 3 is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.
The protective film forming composite sheet 1C shown here is the same as the protective film forming composite sheet 1A shown in fig. 1 except that the adhesive layer 12 is not provided. That is, in the protective film forming composite sheet 1C, the support sheet 10 is composed of only the base material 11. The protective film forming film 13 is laminated on the surface 11a of the substrate 11 (the surface 10a of the support sheet 10), the adhesive layer 16 for jigs is laminated on a part of the surface 13a of the protective film forming film 13, that is, on the region near the peripheral edge, and the release film 15 is laminated on the surface 16a (the upper surface and the side surface) of the adhesive layer 16 and the region of the surface 13a of the protective film forming film 13, on which the adhesive layer 16 for jigs is not laminated.
In the composite sheet 1C for forming a protective film, the adhesion between the film 13 for forming a protective film (i.e., protective film) and the support sheet 10 after curing, in other words, the adhesion between the protective film and the substrate 11 is 50 to 1500mN/25mm.
Like the protective film forming composite sheet 1A shown in fig. 1, the protective film forming composite sheet 1C shown in fig. 3 is used in the following manner: with the release film 15 removed, the back surface of the semiconductor wafer (not shown) is attached to the front surface 13a of the protective film forming film 13, and the upper surface of the front surface 16a of the jig adhesive layer 16 is further attached to a jig such as a ring frame.
Fig. 4 is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.
The protective film forming composite sheet 1D shown here is the same as the protective film forming composite sheet 1C shown in fig. 3 except that the jig adhesive layer 16 is not provided. That is, in the composite sheet 1D for forming a protective film, the protective film 13 is laminated on the surface 11a of the base material 11, and the release film 15 is laminated on the entire surface 13a of the protective film 13.
Like the protective film forming composite sheet 1B shown in fig. 2, the protective film forming composite sheet 1D shown in fig. 4 is used in the following manner: with the release film 15 removed, the rear surface of the semiconductor wafer (not shown) is attached to a partial region on the central side of the front surface 13a of the protective film forming film 13, and the region near the peripheral edge is further attached to a jig such as a ring frame.
Fig. 5 is a cross-sectional view schematically showing still another embodiment of the composite sheet for forming a protective film of the present invention.
The protective film forming composite sheet 1E shown here is the same as the protective film forming composite sheet 1B shown in fig. 2 except that the shape of the protective film forming film is different. That is, the protective film forming composite sheet 1E includes the adhesive layer 12 on the base material 11, and the protective film forming film 23 on the adhesive layer 12. The support sheet 10 is a laminate of the base material 11 and the adhesive layer 12, in other words, the composite sheet 1E for forming a protective film has a structure in which a film 23 for forming a protective film is laminated on the surface 10a of one side of the support sheet 10. The protective film forming composite sheet 1E further includes a release film 15 on the protective film forming film 23.
In the protective film forming composite sheet 1E, the adhesive layer 12 is laminated on the surface 11a of the base material 11, and the protective film forming film 23 is laminated on a part of the surface 12a of the adhesive layer 12, that is, on the central side region. The release film 15 is laminated on the surface 23a (upper surface and side surface) of the protective film forming film 23 and the area of the surface 12a of the adhesive layer 12 where the protective film forming film 23 is not laminated.
When the protective film forming composite sheet 1E is viewed from above, the surface area of the protective film forming film 23 is smaller than that of the adhesive layer 12, and has a circular shape, for example.
In the protective film-forming composite sheet 1E, the adhesion between the cured protective film-forming film 23 (i.e., protective film) and the support sheet 10, in other words, the adhesion between the protective film and the adhesive layer 12 is 50 to 1500mN/25mm.
The protective film forming composite sheet 1E shown in fig. 5 is used in the following manner: with the release film 15 removed, the back surface of the semiconductor wafer (not shown) is attached to the front surface 23a of the protective film forming film 23, and the area of the front surface 12a of the adhesive layer 12 where the protective film forming film 23 is not laminated is further attached to a jig such as a ring frame.
In the protective film forming composite sheet 1E shown in fig. 5, an adhesive layer for a jig (not shown) may be laminated on the area of the surface 12a of the adhesive layer 12 where the protective film forming film 23 is not laminated in the same manner as shown in fig. 1 and 3. Like the composite sheet for forming a protective film shown in fig. 1 and 3, the composite sheet for forming a protective film 1E provided with such an adhesive layer for a jig is used in such a manner that the surface of the adhesive layer for a jig is attached to a jig such as a ring frame.
As described above, the composite sheet for forming a protective film of the present invention may be provided with the adhesive layer for a jig, regardless of the form of the support sheet and the film for forming a protective film. As shown in fig. 1 and 3, the composite sheet for forming a protective film of the present invention having a pressure-sensitive adhesive layer for a jig is preferably provided with a pressure-sensitive adhesive layer for a jig on a film for forming a protective film.
The composite sheet for forming a protective film of the present invention is not limited to the composite sheet shown in fig. 1 to 5, and a composite sheet having a part of the composite sheet for forming a protective film shown in fig. 1 to 5 may be modified or deleted, or a composite sheet having another structure may be added to the composite sheet for forming a protective film described above, as far as the effect of the present invention is not impaired.
For example, in the composite sheet for forming a protective film shown in fig. 3 and 4, an intermediate layer may be provided between the base material 11 and the film 13 for forming a protective film. As the intermediate layer, an arbitrary intermediate layer may be selected according to the purpose.
In the composite sheet for forming a protective film shown in fig. 1, 2 and 5, an intermediate layer may be provided between the base material 11 and the adhesive layer 12. That is, in the composite sheet for forming a protective film of the present invention, the support sheet may be formed by stacking the base material, the intermediate layer, and the adhesive layer in this order. Here, the intermediate layer means the same intermediate layer as that which can be provided in the protective film forming composite sheet shown in fig. 3 and 4.
The protective film-forming composite sheet shown in fig. 1 to 5 may be provided with a layer other than the intermediate layer at any position.
In the composite sheet for forming a protective film of the present invention, a part of the gap may be generated between the release film and the layer in direct contact with the release film.
In the composite sheet for forming a protective film of the present invention, the size and shape of each layer can be arbitrarily adjusted according to the purpose.
In the composite sheet for forming a protective film of the present invention, as described below, it is preferable that the layer of the support sheet that is in direct contact with the film for forming a protective film, such as the adhesive layer, is non-energy ray curable. Such a composite sheet for forming a protective film enables easier pickup of a semiconductor chip having a protective film on the back surface.
The support sheet may be transparent or opaque, or may be colored according to the purpose.
Among them, in the present invention in which the protective film forming film has energy ray curability, it is preferable that the support sheet transmits energy rays.
For example, the transmittance of light having a wavelength of 375nm in the support sheet is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. When the light transmittance is in such a range, the curing degree of the protective film forming film is further improved by irradiation of the protective film forming film with energy rays (ultraviolet rays) through the support sheet.
On the other hand, the upper limit value of the transmittance of light having a wavelength of 375nm in the supporting sheet is not particularly limited. For example, the transmittance of light may be 95% or less.
In the support sheet, the transmittance of light having a wavelength of 532nm is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. When the light transmittance is in such a range, the protective film forming film or the protective film is irradiated with laser light through the support sheet, and printing is performed thereon, the printing can be performed more clearly.
On the other hand, in the support sheet, the upper limit value of the transmittance of light having a wavelength of 532nm is not particularly limited. For example, the transmittance of light may be 95% or less.
In the support sheet, the transmittance of light having a wavelength of 1064nm is preferably 30% or more, more preferably 50% or more, and particularly preferably 70% or more. When the light transmittance is in such a range, the protective film forming film or the protective film is irradiated with laser light through the support sheet, and printing is performed thereon, the printing can be performed more clearly.
On the other hand, the upper limit value of the transmittance of light having a wavelength of 1064nm in the support sheet is not particularly limited. For example, the transmittance of light may be 95% or less.
Next, each layer constituting the support sheet will be described in further detail.
Base material
The base material is in the form of a sheet or film, and examples of the constituent material thereof include various resins.
Examples of the resin include polyethylene such as Low Density Polyethylene (LDPE), linear Low Density Polyethylene (LLDPE), and High Density Polyethylene (HDPE); polyolefins other than polyethylene, such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-vinyl acetate copolymers, ethylene- (meth) acrylic acid ester copolymers, ethylene-norbornene copolymers and other ethylene copolymers (copolymers obtained by using ethylene as a monomer); vinyl chloride resins (resins obtained by using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymers; a polystyrene; polycycloolefins; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene 2, 6-naphthalate, and wholly aromatic polyesters each having an aromatic ring group in its constituent unit; copolymers of two or more of the polyesters; poly (meth) acrylates; polyurethane; a urethane acrylate; polyimide; a polyamide; a polycarbonate; a fluororesin; polyacetal; modified polyphenylene ether; polyphenylene sulfide; polysulfone; polyetherketone, and the like.
The resin may be, for example, a polymer alloy such as a mixture of the polyester and a resin other than the polyester. Preferably, the amount of resin other than polyester in the polymer alloy of the polyester and resin other than polyester is a small amount.
Examples of the resin include crosslinked resins obtained by crosslinking one or more of the above resins; modified resins such as ionomers of one or two or more of the above resins exemplified above are used.
In the present specification, "(meth) acrylic acid" is a concept including both "acrylic acid" and "methacrylic acid". Similar terms to (meth) acrylic acid are also the same.
The resin constituting the base material may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
The substrate may be composed of one layer (single layer) or two or more layers, and when the substrate is composed of a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited.
The thickness of the base material is preferably 50 to 300. Mu.m, more preferably 60 to 100. Mu.m. By setting the thickness of the base material to such a range, the flexibility of the composite sheet for forming a protective film and the adhesion to a semiconductor wafer or a semiconductor chip are further improved.
Here, the "thickness of the substrate" refers to the thickness of the entire substrate, and for example, the thickness of the substrate composed of a plurality of layers refers to the total thickness of all the layers constituting the substrate.
The substrate is preferably a substrate having high thickness accuracy, that is, a substrate in which variation in thickness is suppressed at any position. Examples of the material that can be used as the material constituting the base material having such high thickness accuracy include polyethylene, polyolefin other than polyethylene, polyethylene terephthalate, and ethylene-vinyl acetate copolymer.
The base material may contain, in addition to the main constituent materials such as the resin, various known additives such as a filler, a colorant, an antistatic agent, an antioxidant, an organic lubricant, a catalyst, and a softener (plasticizer).
The optical characteristics of the base material may be such that they satisfy the optical characteristics of the support sheet described above. That is, the substrate may be transparent or opaque, may be colored according to the purpose, or may be vapor-deposited with other layers.
In the present invention in which the protective film forming film has energy ray curability, it is preferable that the base material transmits energy rays.
In order to improve the adhesion to other layers such as an adhesive layer provided thereon, the substrate may be one having been subjected to an oxidizing treatment such as a blast treatment, a solvent treatment, a surface roughening treatment, a corona discharge treatment, an electron beam irradiation treatment, a plasma treatment, an ozone/ultraviolet irradiation treatment, a flame treatment, a chromic acid treatment, a hot air treatment, or the like.
In addition, the substrate may be a substrate whose surface is treated with a primer.
In addition, when the antistatic coating layer and the protective film-forming composite sheet are laminated and stored, the substrate may have a layer or the like for preventing the adhesion of the substrate to another sheet or the adhesion of the substrate to a suction table.
Among them, from the viewpoint of suppressing the occurrence of a broken piece of the substrate due to the friction of the blade at the time of cutting, it is particularly preferable that the substrate is a substrate whose surface is subjected to the electron beam irradiation treatment.
The substrate can be produced by a known method. For example, a resin-containing substrate can be produced by molding a resin composition containing the resin.
Adhesive layer
The adhesive layer is in the form of a sheet or film and contains an adhesive.
Examples of the adhesive include adhesive resins such as acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyvinyl ethers, polycarbonates, and ester resins, and acrylic resins are preferable.
In the present invention, the term "adhesive resin" is a concept including both a resin having adhesive properties and a resin having adhesive properties, and includes, for example, not only a resin having adhesive properties itself but also a resin exhibiting adhesive properties by being used together with other components such as additives, or a resin exhibiting adhesive properties by the presence of a trigger (trigger) such as heat or water.
The adhesive layer may be composed of one layer (single layer) or two or more layers, and when composed of a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited.
The thickness of the adhesive layer is preferably 1 to 100. Mu.m, more preferably 1 to 60. Mu.m, particularly preferably 1 to 30. Mu.m.
Here, the "thickness of the adhesive layer" refers to the thickness of the entire adhesive layer, and for example, the thickness of the adhesive layer composed of a plurality of layers refers to the total thickness of all the layers constituting the adhesive layer.
The optical properties of the adhesive layer may be such that they satisfy the optical properties of the support sheet described above. That is, the adhesive layer may be transparent or opaque, or may be colored according to the purpose.
In the present invention in which the protective film forming film has energy ray curability, it is preferable that the adhesive layer transmits energy rays.
The adhesive layer may be formed using an energy ray-curable adhesive or a non-energy ray-curable adhesive. The adhesive layer formed by using the energy ray-curable adhesive can easily adjust physical properties before and after curing.
Adhesive composition
The adhesive layer can be formed using an adhesive composition containing an adhesive. For example, the adhesive composition is applied to the surface of the adhesive layer to be formed and dried as necessary, whereby the adhesive layer can be formed at the target site. A more specific method of forming the adhesive layer will be described in detail later together with a method of forming other layers. The content ratio of the components in the adhesive composition, which are not gasified at normal temperature, is generally the same as the content ratio of the components in the adhesive layer. In the present specification, the term "normal temperature" refers to a temperature at which cooling or heating is not particularly performed, that is, a normal temperature, and examples thereof include a temperature of 15 to 25 ℃.
The adhesive composition may be applied by a known method, and examples thereof include various coating machines such as an air knife coater, a blade coater, a bar coater, a gravure coater, a roll knife coater, a curtain coater, a die coater, a blade coater, a screen coater (screen coater), a meyer bar coater, and a kiss coater.
The drying condition of the adhesive composition is not particularly limited, but when the adhesive composition contains a solvent described later, it is preferable to perform heat drying. The adhesive composition containing the solvent is preferably dried, for example, at 70 to 130℃for 10 seconds to 5 minutes.
When the adhesive layer is energy ray-curable, examples of the adhesive composition containing an energy ray-curable adhesive, namely an energy ray-curable adhesive composition, include an adhesive composition (I-1) containing a non-energy ray-curable adhesive resin (I-1 a) (hereinafter, sometimes abbreviated as "adhesive resin (I-1 a)") and an energy ray-curable compound; an adhesive composition (I-2) comprising an energy ray-curable adhesive resin (I-2 a) (hereinafter, sometimes abbreviated as "adhesive resin (I-2 a)") having an unsaturated group introduced into a side chain of the non-energy ray-curable adhesive resin (I-1 a); an adhesive composition (I-3) containing the adhesive resin (I-2 a) and an energy ray-curable compound.
Adhesive composition (I-1)
As described above, the adhesive composition (I-1) contains the non-energy ray-curable adhesive resin (I-1 a) and the energy ray-curable compound.
[ Adhesive resin (I-1 a) ]
Preferably, the adhesive resin (I-1 a) is an acrylic resin.
Examples of the acrylic resin include acrylic polymers having at least a structural unit derived from an alkyl (meth) acrylate.
The structural units of the acrylic resin may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
Examples of the alkyl (meth) acrylate include alkyl (meth) acrylates having 1 to 20 carbon atoms in the alkyl group constituting the alkyl ester, and the alkyl group is preferably linear or branched.
Examples of alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, myristyl (meth) acrylate, pentadecyl (meth) acrylate, palmityl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, and mixtures thereof, eicosyl (meth) acrylate, and the like.
From the point of improving the adhesive force of the adhesive layer, it is preferable that the acrylic polymer has a structural unit derived from an alkyl (meth) acrylate having 4 or more carbon atoms in the alkyl group. The number of carbon atoms of the alkyl group is preferably 4 to 12, more preferably 4 to 8, from the point of further improving the adhesive force of the adhesive layer. Further, the alkyl (meth) acrylate in which the alkyl group has 4 or more carbon atoms is preferably an alkyl acrylate.
The acrylic polymer preferably further has a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from an alkyl (meth) acrylate.
Examples of the functional group-containing monomer include a starting point of crosslinking by a reaction between the functional group and a crosslinking agent described later, and a functional group-containing monomer in which an unsaturated group is introduced into a side chain of an acrylic polymer by a reaction between the functional group and an unsaturated group in an unsaturated group-containing compound described later.
Examples of the functional group in the functional group-containing monomer include a hydroxyl group, a carboxyl group, an amino group, and an epoxy group.
That is, examples of the functional group-containing monomer include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, and the like.
Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylates such as hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate; and non (meth) acrylic unsaturated alcohols (unsaturated alcohols having no (meth) acryl skeleton) such as vinyl alcohol and allyl alcohol.
Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth) acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as fumaric acid, itaconic acid, maleic acid, and citraconic acid; anhydrides of the ethylenically unsaturated dicarboxylic acids; and carboxyalkyl (meth) acrylates such as 2-carboxyethyl methacrylate.
Preferably, the functional group-containing monomer is a hydroxyl group-containing monomer, a carboxyl group-containing monomer, and more preferably a hydroxyl group-containing monomer.
The functional group-containing monomer constituting the acrylic polymer may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the acrylic polymer, the content of the structural unit derived from the functional group-containing monomer is preferably 1 to 35% by mass, more preferably 2 to 32% by mass, and particularly preferably 3 to 30% by mass, relative to the total amount of the structural units.
The acrylic polymer may further have a structural unit derived from other monomers in addition to a structural unit derived from the alkyl (meth) acrylate.
The other monomer is not particularly limited as long as it can be copolymerized with an alkyl (meth) acrylate or the like.
Examples of the other monomer include styrene, α -methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.
The other monomers constituting the acrylic polymer may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
The acrylic polymer can be used as the above-mentioned non-energy ray-curable adhesive resin (I-1 a).
On the other hand, a substance produced by reacting an unsaturated group-containing compound having an energy ray-polymerizable unsaturated group (energy ray-polymerizable group) with a functional group in the acrylic polymer can be used as the above-mentioned energy ray-curable adhesive resin (I-2 a).
The adhesive resin (I-1 a) contained in the adhesive composition (I-1) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
The content of the adhesive resin (I-1 a) in the adhesive composition (I-1) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, and particularly preferably 15 to 90% by mass.
[ Energy ray-curable Compound ]
The energy ray-curable compound contained in the adhesive composition (I-1) includes a monomer or oligomer having an energy ray-polymerizable unsaturated group and curable by irradiation with energy rays.
Examples of the monomer in the energy ray-curable compound include polyvalent (meth) acrylates such as trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1, 4-butanediol di (meth) acrylate, and 1, 6-hexanediol (meth) acrylate; urethane (meth) acrylates; polyester (meth) acrylates; polyether (meth) acrylates; epoxy (meth) acrylates, and the like.
Examples of the oligomer in the energy ray-curable compound include oligomers obtained by polymerizing the monomers exemplified above.
The energy ray-curable compound is preferably urethane (meth) acrylate or urethane (meth) acrylate oligomer in terms of having a large molecular weight and not easily lowering the storage modulus of the adhesive layer.
The energy ray-curable compound contained in the adhesive composition (I-1) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-1), the content of the energy ray-curable compound is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, and particularly preferably 10 to 85% by mass.
[ Cross-linking agent ]
When the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from an alkyl (meth) acrylate is used as the adhesive resin (I-1 a), it is preferable that the adhesive composition (I-1) further contains a crosslinking agent.
The crosslinking agent crosslinks the adhesive resins (I-1 a) to each other, for example, by reaction with the functional groups.
Examples of the crosslinking agent include isocyanate crosslinking agents (crosslinking agents having an isocyanate group) such as toluene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy-based crosslinking agents (crosslinking agents having a glycidyl group) such as ethylene glycol glycidyl ether; triazine-based crosslinking agents (crosslinking agents having an aziridine group) such as Hexa [1- (2-methyl) -aziridinyl ] triphosphatriazine ] triazine triphosphate; metal chelate crosslinking agents (crosslinking agents having a metal chelate structure) such as aluminum chelates; isocyanurate-based crosslinking agents (crosslinking agents having an isocyanuric acid skeleton), and the like.
The crosslinking agent is preferably an isocyanate-based crosslinking agent from the viewpoint of improving the cohesive force of the adhesive and thereby improving the adhesive force of the adhesive layer, from the viewpoint of easy availability, or the like.
The crosslinking agent contained in the adhesive composition (I-1) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-1), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass, relative to 100 parts by mass of the content of the adhesive resin (I-1 a).
[ Photopolymerization initiator ]
The adhesive composition (I-1) may further contain a photopolymerization initiator. Even when the adhesive composition (I-1) containing the photopolymerization initiator is irradiated with energy rays of relatively low energy such as ultraviolet rays, the curing reaction proceeds sufficiently.
Examples of the photopolymerization initiator include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal; acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-dimethoxy-1, 2-diphenylethan-1-one, and the like; acylphosphine oxide compounds such as phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide and 2,4, 6-trimethylbenzoyl diphenyl phosphine oxide; sulfur compounds such as benzyl phenyl sulfide and tetramethylthiuram monosulfide; alpha-ketol compounds such as 1-hydroxycyclohexyl phenyl ketone; azo compounds such as azobisisobutyronitrile; a titanocene compound such as titanocene; thioxanthone compounds such as thioxanthone; a peroxide compound; diketone compounds such as diacetyl; benzil (benzil); a dibenzoyl group; benzophenone; 2, 4-diethylthioxanthone; 1, 2-diphenylmethane; 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] propanone; 2-chloroanthraquinone, and the like.
As the photopolymerization initiator, for example, a quinone compound such as 1-chloroanthraquinone can be used; amine and the like.
The photopolymerization initiator contained in the adhesive composition (I-1) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-1), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the content of the energy ray-curable compound.
[ Other additives ]
The adhesive composition (I-1) may contain other additives not corresponding to any of the above-mentioned components within a range not impairing the effects of the present invention.
Examples of the other additives include known additives such as antistatic agents, antioxidants, softeners (plasticizers), fillers (fillers), rust inhibitors, colorants (pigments and dyes), sensitizers, tackifiers, reaction retarders, and crosslinking accelerators (catalysts).
The reaction retarder is an additive for inhibiting the progress of an unintended crosslinking reaction in the adhesive composition (I-1) during storage, for example, by the action of a catalyst mixed in the adhesive composition (I-1). Examples of the reaction retarder include a reaction retarder that forms a chelate complex (chelate complex) with a chelate compound corresponding to a catalyst, and more specifically, a reaction retarder having two or more carbonyl groups (-C (=o) -) in 1 molecule.
The other additives contained in the adhesive composition (I-1) may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-1), the content of the other additives is not particularly limited, and may be appropriately selected according to the kind thereof.
[ Solvent ]
The adhesive composition (I-1) may contain a solvent. The adhesive composition (I-1) contains a solvent to improve the coating suitability for the surface of the object to be coated.
Preferably, the solvent is an organic solvent, and examples of the organic solvent include ketones such as methyl ethyl ketone and acetone; esters (carboxylic acid esters) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; alcohols such as 1-propanol and 2-propanol.
The solvent may be used in the adhesive composition (I-1) without removing the solvent used for producing the adhesive resin (I-1 a) from the adhesive resin (I-1 a), or may be added separately in the adhesive composition (I-1) with the same or a different solvent from the solvent used for producing the adhesive resin (I-1 a).
The solvent contained in the adhesive composition (I-1) may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-1), the content of the solvent is not particularly limited, and may be appropriately adjusted.
Adhesive composition (I-2)
As described above, the adhesive composition (I-2) contains the energy ray-curable adhesive resin (I-2 a) having an unsaturated group introduced into a side chain of the non-energy ray-curable adhesive resin (I-1 a).
[ Adhesive resin (I-2 a) ]
The adhesive resin (I-2 a) is obtained, for example, by reacting an unsaturated group-containing compound having an energy ray polymerizable unsaturated group with a functional group in the adhesive resin (I-1 a).
The unsaturated group-containing compound is a compound having, in addition to an energy ray polymerizable unsaturated group, a group capable of bonding to the adhesive resin (I-1 a) by reacting with a functional group in the adhesive resin (I-1 a).
Examples of the energy ray-polymerizable unsaturated group include a (meth) acryloyl group, a vinyl (ethylene) group, and an allyl (2-propenyl) group, and a (meth) acryloyl group is preferable.
Examples of the group capable of bonding to the functional group in the adhesive resin (I-1 a) include an isocyanate group and a glycidyl group capable of bonding to a hydroxyl group or an amino group, and a hydroxyl group and an amino group capable of bonding to a carboxyl group or an epoxy group.
Examples of the unsaturated group-containing compound include (meth) acryloyloxyethyl isocyanate, (meth) acryloyloxyisocyanate, and glycidyl (meth) acrylate.
The adhesive resin (I-2 a) contained in the adhesive composition (I-2) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
The content of the adhesive resin (I-2 a) in the adhesive composition (I-2) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, and particularly preferably 10 to 90% by mass.
[ Cross-linking agent ]
For example, when the acrylic polymer having a structural unit derived from a functional group-containing monomer, which is the same as that in the adhesive resin (I-1 a), is used as the adhesive resin (I-2 a), it is preferable that the adhesive composition (I-2) further contains a crosslinking agent.
The crosslinking agent in the adhesive composition (I-2) may be the same as the crosslinking agent in the adhesive composition (I-1).
The crosslinking agent contained in the adhesive composition (I-2) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-2), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass, relative to 100 parts by mass of the content of the adhesive resin (I-2 a).
[ Photopolymerization initiator ]
The adhesive composition (I-2) may further contain a photopolymerization initiator. Even if the adhesive composition (I-2) containing the photopolymerization initiator is irradiated with energy rays of relatively low energy such as ultraviolet rays, the curing reaction proceeds sufficiently.
The photopolymerization initiator in the adhesive composition (I-2) may be the same as the photopolymerization initiator in the adhesive composition (I-1).
The photopolymerization initiator contained in the adhesive composition (I-2) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-2), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the content of the adhesive resin (I-2 a).
[ Other additives ]
The adhesive composition (I-2) may contain other additives not corresponding to any of the above-mentioned components within a range not impairing the effects of the present invention.
The other additives in the adhesive composition (I-2) may be the same as those in the adhesive composition (I-1).
The other additives contained in the adhesive composition (I-2) may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-2), the content of the other additives is not particularly limited, and may be appropriately selected according to the kind thereof.
[ Solvent ]
The adhesive composition (I-2) may also contain a solvent for the same purpose as in the case of the adhesive composition (I-1).
The solvent in the adhesive composition (I-2) may be the same as the solvent in the adhesive composition (I-1).
The solvent contained in the adhesive composition (I-2) may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-2), the content of the solvent is not particularly limited, and may be appropriately adjusted.
Adhesive composition (I-3)
As described above, the adhesive composition (I-3) contains the adhesive resin (I-2 a) and an energy ray-curable compound.
The content of the adhesive resin (I-2 a) in the adhesive composition (I-3) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, and particularly preferably 15 to 90% by mass.
[ Energy ray-curable Compound ]
The energy ray-curable compound contained in the adhesive composition (I-3) includes monomers or oligomers having an energy ray-polymerizable unsaturated group and curable by irradiation with energy rays, and includes the same energy ray-curable compound as the energy ray-curable compound contained in the adhesive composition (I-1).
The energy ray-curable compound contained in the adhesive composition (I-3) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-3), the content of the energy ray-curable compound is preferably 0.01 to 300 parts by mass, more preferably 0.03 to 200 parts by mass, and particularly preferably 0.05 to 100 parts by mass, relative to 100 parts by mass of the content of the adhesive resin (I-2 a).
[ Photopolymerization initiator ]
The adhesive composition (I-3) may further contain a photopolymerization initiator. Even if the adhesive composition (I-3) containing the photopolymerization initiator is irradiated with energy rays of relatively low energy such as ultraviolet rays, the curing reaction proceeds sufficiently.
The photopolymerization initiator in the adhesive composition (I-3) may be the same as the photopolymerization initiator in the adhesive composition (I-1).
The photopolymerization initiator contained in the adhesive composition (I-3) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-3), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the total content of the adhesive resin (I-2 a) and the energy ray-curable compound.
[ Other additives ]
The adhesive composition (I-3) may contain other additives not corresponding to any of the above-mentioned components within a range not impairing the effects of the present invention.
The other additives mentioned above are the same as those in the adhesive composition (I-1).
The other additives contained in the adhesive composition (I-3) may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-3), the content of the other additives is not particularly limited, and may be appropriately selected according to the kind thereof.
[ Solvent ]
The adhesive composition (I-3) may also contain a solvent for the same purpose as in the case of the adhesive composition (I-1).
The solvent in the adhesive composition (I-3) may be the same as the solvent in the adhesive composition (I-1).
The solvent contained in the adhesive composition (I-3) may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-3), the content of the solvent is not particularly limited, and may be appropriately adjusted.
Adhesive compositions other than the adhesive compositions (I-1) to (I-3)
The adhesive composition (I-1), the adhesive composition (I-2) and the adhesive composition (I-3) have been described so far, and the materials described as the components contained therein can be used in all the adhesive compositions other than the three adhesive compositions (in this specification, referred to as "adhesive compositions other than the adhesive compositions (I-1) to (I-3)").
The adhesive compositions other than the adhesive compositions (I-1) to (I-3) include non-energy ray-curable adhesive compositions other than the energy ray-curable adhesive compositions.
Examples of the non-energy ray-curable adhesive composition include an adhesive composition (I-4) containing a non-energy ray-curable adhesive resin (I-1 a) such as an acrylic resin, a urethane resin, a rubber resin, a silicone resin, an epoxy resin, a polyvinyl ether, a polycarbonate, and an ester resin, and a non-energy ray-curable adhesive composition containing an acrylic resin is preferable.
The adhesive compositions other than the adhesive compositions (I-1) to (I-3) preferably contain one or more crosslinking agents, and the content thereof may be set to be the same as in the case of the adhesive composition (I-1) and the like.
Adhesive composition (I-4)
As a preferred adhesive composition (I-4), for example, an adhesive composition containing the adhesive resin (I-1 a) and a crosslinking agent can be mentioned.
[ Adhesive resin (I-1 a) ]
As the adhesive resin (I-1 a) in the adhesive composition (I-4), the same adhesive resin (I-1 a) as that in the adhesive composition (I-1) can be mentioned.
The adhesive resin (I-1 a) contained in the adhesive composition (I-4) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
The content of the adhesive resin (I-1 a) in the adhesive composition (I-4) is preferably 5 to 99% by mass, more preferably 10 to 95% by mass, and particularly preferably 15 to 90% by mass.
[ Cross-linking agent ]
When the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from an alkyl (meth) acrylate is used as the adhesive resin (I-1 a), it is preferable that the adhesive composition (I-4) further contains a crosslinking agent.
The crosslinking agent in the adhesive composition (I-4) may be the same as the crosslinking agent in the adhesive composition (I-1).
The crosslinking agent contained in the adhesive composition (I-4) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-4), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and particularly preferably 0.3 to 15 parts by mass, relative to 100 parts by mass of the content of the adhesive resin (I-1 a).
[ Other additives ]
The adhesive composition (I-4) may contain other additives not corresponding to any of the above-mentioned components within a range not impairing the effects of the present invention.
The other additives mentioned above are the same as those in the adhesive composition (I-1).
The other additives contained in the adhesive composition (I-4) may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-4), the content of the other additives is not particularly limited, and may be appropriately selected according to the kind thereof.
[ Solvent ]
The adhesive composition (I-4) may also contain a solvent for the same purpose as in the case of the adhesive composition (I-1).
The solvent in the adhesive composition (I-4) may be the same as the solvent in the adhesive composition (I-1).
The solvent contained in the adhesive composition (I-4) may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
In the adhesive composition (I-4), the content of the solvent is not particularly limited, and may be appropriately adjusted.
In the composite sheet for forming a protective film of the present invention, the adhesive layer is preferably non-energy ray-curable. This is because, if the adhesive layer is energy ray curable, simultaneous curing of the adhesive layer cannot be suppressed when the protective film forming film is cured by irradiation of energy rays. If the adhesive layer and the protective film forming film are cured at the same time, the cured protective film forming film and the adhesive layer are attached at the interface thereof to such an extent that peeling cannot be performed. In this case, it is difficult to peel the semiconductor chip having the protective film forming film after curing (hereinafter, sometimes referred to as "protective film-attached semiconductor chip") on the back surface from the support sheet having the adhesive layer after curing, and thus the protective film-attached semiconductor chip cannot be picked up normally. In the support sheet of the present invention, such a problem can be avoided with certainty by making the adhesive layer non-energy ray-curable, and the semiconductor chip with the protective film can be picked up more easily.
Here, the effect when the adhesive layer is non-energy ray curable is described, but even if the layer of the support sheet in direct contact with the protective film forming film is a layer other than the adhesive layer, the same effect is exhibited as long as the layer is non-energy ray curable.
Process for the preparation of an adhesive composition
The adhesive compositions other than the adhesive compositions (I-1) to (I-3), such as the adhesive compositions (I-1) to (I-3), or the adhesive composition (I-4), can be obtained by blending the above-mentioned adhesives, and if necessary, the components other than the above-mentioned adhesives, etc. for constituting the adhesive composition.
The order of addition in blending the components is not particularly limited, and two or more components may be added simultaneously.
When a solvent is used, the solvent may be mixed with any blend component other than the solvent to pre-dilute the blend component, or the solvent may be mixed with any blend component other than the solvent to use the blend component without pre-diluting the blend component.
The method of mixing the components at the time of blending is not particularly limited, and may be appropriately selected from the following known methods: a method of mixing by rotating a stirrer, stirring blades, or the like; a method of mixing using a stirrer; and a method of mixing by applying ultrasonic waves.
The temperature and time at the time of adding and mixing the components are not particularly limited as long as the components to be blended are not degraded, and the temperature is preferably 15 to 30 ℃.
Film for forming protective film
In the present invention, the adhesion between the protective film and the support sheet obtained by curing the protective film-forming film is 50 to 1500mN/25mm, preferably 52 to 1450mN/25mm, more preferably 53 to 1430mN/25mm. When the adhesion is equal to or higher than the lower limit, the non-target semiconductor chip with the protective film can be suppressed from being picked up, and the target semiconductor chip with the protective film can be picked up with high selectivity. Further, by setting the adhesion to the upper limit or less, cracking and chipping of the semiconductor chip can be suppressed when picking up the semiconductor chip with the protective film. In this way, by making the adhesion force within a specific range, the composite sheet for forming a protective film has good pickup suitability.
In the present invention, even after the film for forming a protective film is cured, the laminated structure is referred to as a "composite sheet for forming a protective film" as long as the laminated structure of the support sheet and the cured product of the film for forming a protective film (in other words, the support sheet and the protective film) is maintained.
The adhesion between the protective film and the support sheet was measured by the following method.
That is, a protective film forming composite sheet having a width of 25mm and an arbitrary length is attached to an adherend through its protective film forming film.
Then, the protective film-forming film was cured by irradiation with energy rays to form a protective film, and then the support sheet was peeled from the protective film attached to the adherend at a peeling speed of 300 mm/min. The peeling at this time is so-called 180 ° peeling, that is, peeling the support sheet in the longitudinal direction thereof (the longitudinal direction of the composite sheet for forming the protective film) so that the surfaces of the protective film and the support sheet in contact with each other form an angle of 180 ° with each other. Then, the load (peel force) at 180℃peeling was measured, and the measured value was used as the adhesive force (mN/25 mm).
The length of the protective film-forming composite sheet to be measured is not particularly limited as long as it is within a range in which the adhesive force can be stably detected, and is preferably 100to 300mm. In the measurement, it is preferable that the protective film-forming composite sheet is attached to the adherend, and the attached state of the protective film-forming composite sheet is stabilized.
In the present invention, the adhesion between the protective film forming film and the support sheet is not particularly limited, and the peeling between the protective film forming film and the support sheet can be suppressed from the dicing, for example, from the point where the semiconductor chip having the protective film forming film on the back surface thereof can be suppressed from scattering from the support sheet, and is preferably 80mN/25mm or more. Further, from the point where the effect is more remarkably obtained, the adhesion between the protective film forming film and the support sheet is more preferably 100mN/25mm or more, still more preferably 150mN/25mm or more, particularly preferably 200mN/25mm or more.
On the other hand, the upper limit of the adhesion force between the protective film forming film and the support sheet is not particularly limited. For example, the adhesion force may be any one of 4000mN/25mm or less, 3500mN/25mm or less, 3000mN/25mm or less, and the like. However, these upper limit values are only one example of preferable upper limit values.
The adhesion between the protective film forming film and the support sheet can be measured by the same method as the adhesion between the protective film and the support sheet described above, except that the curing of the protective film forming film for measurement by irradiation of energy rays is not performed.
For example, the type and amount of the component contained in the protective film-forming film, the constituent material of the layer of the support sheet on which the protective film-forming film is provided, the surface state of the layer, and the like can be adjusted to appropriately adjust the adhesion between the protective film and the support sheet and the adhesion between the protective film-forming film and the support sheet.
For example, the kind and amount of the component contained in the protective film-forming film can be adjusted by the kind and amount of the component contained in the protective film-forming composition described later. Further, by adjusting the type and content of the polymer (b) having no energy ray-curable group, the content of the filler (d), or the content of the crosslinking agent (f) among the components contained in the composition for forming a protective film, for example, the adhesion between the protective film or the film for forming a protective film and the supporting sheet can be more easily adjusted.
In addition, for example, when the layer of the support sheet on which the protective film forming film is provided is an adhesive layer, the constituent material of the adhesive layer can be appropriately adjusted by adjusting the kind and amount of the component contained in the adhesive layer. The kind and amount of the component contained in the adhesive layer can be adjusted by the kind and amount of the component contained in the adhesive composition.
On the other hand, when the layer of the support sheet on which the protective film forming film is provided is a base material, the adhesion between the protective film or the protective film forming film and the support sheet can be adjusted by the surface state of the base material in addition to the adjustment by the constituent material of the base material. The surface state of the substrate can be adjusted by, for example, performing any one of the following treatments listed above as a surface treatment for improving the adhesion between the substrate and other layers: namely, the relief treatment by sand blasting, solvent treatment, or the like; oxidation treatments such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone/ultraviolet irradiation treatment, flame treatment, chromic acid treatment, and hot air treatment; primer treatment, and the like.
The protective film-forming film has an energy ray-curable property, and examples thereof include a protective film-forming film containing an energy ray-curable component (a).
Preferably, the energy ray-curable component (a) is uncured, preferably it has tackiness, more preferably it is uncured and has tackiness.
The protective film may be formed as one layer (single layer) or as a plurality of two or more layers, and when the protective film is formed as a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the plurality of layers is not particularly limited.
The thickness of the protective film-forming film is preferably 1 to 100. Mu.m, more preferably 5 to 75. Mu.m, particularly preferably 5 to 50. Mu.m. By setting the thickness of the protective film forming film to the above lower limit value or more, a protective film having higher protective ability can be formed. Further, by setting the thickness of the protective film forming film to the above-described upper limit value or less, the thickness can be suppressed from becoming excessive.
Here, the "thickness of the protective film forming film" refers to the thickness of the entire protective film forming film, and for example, the thickness of the protective film forming film composed of a plurality of layers refers to the total thickness of all the layers constituting the protective film forming film.
The curing condition for curing the protective film forming film to form the protective film is not particularly limited as long as the protective film has a degree of curing sufficient to perform its function, and may be appropriately selected according to the type of the protective film forming film.
For example, the illuminance of the energy ray at the time of curing the protective film-forming film is preferably 4 to 280mW/cm 2. The amount of the energy ray at the time of curing is preferably 3 to 1000mJ/cm 2.
Composition for forming protective film
The protective film-forming film can be formed using a protective film-forming composition containing the constituent materials thereof. For example, the protective film-forming composition is applied to the surface to be formed of the protective film-forming film and dried as necessary, whereby the protective film-forming film can be formed at the target site. The content ratio of the components that do not vaporize at ordinary temperature in the composition for forming a protective film is generally the same as the content ratio of the components of the film for forming a protective film. Here, "normal temperature" is the same as described above.
The composition for forming a protective film may be applied by a known method, and examples thereof include methods using various coaters such as an air knife coater, a blade coater, a bar coater, a gravure coater, a roll knife coater, a curtain coater, a die coater, a knife coater, a screen coater, a meyer bar coater, and a kiss coater.
The drying condition of the composition for forming a protective film is not particularly limited, but when the composition for forming a protective film contains a solvent described later, it is preferable to perform heat drying, and in this case, it is preferable to perform drying under conditions of, for example, 70 to 130 ℃ for 10 seconds to 5 minutes.
Composition (IV-1) for forming protective film
Examples of the composition for forming a protective film include a composition (IV-1) for forming a protective film containing the above-mentioned energy ray-curable component (a).
[ Energy ray-curable component (a) ]
The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and is also a component for imparting film-forming properties, flexibility, and the like to the film for forming a protective film.
Examples of the energy ray-curable component (a) include a polymer (a 1) having an energy ray-curable group and having a weight average molecular weight of 80000 ~ 2000000, and a compound (a 2) having an energy ray-curable group and having a molecular weight of 100 to 80000. The polymer (a 1) may be a crosslinked material at least a part of which is crosslinked with a crosslinking agent (f) described later, or may be an uncrosslinked material.
In the present specification, unless otherwise indicated, the weight average molecular weight refers to a polystyrene equivalent measured by Gel Permeation Chromatography (GPC).
(Polymer (a 1) having an energy ray-curable group and having a weight-average molecular weight of 80000 ~ 2000000)
Examples of the polymer (a 1) having an energy ray-curable group and a weight average molecular weight of 80000 ~ 2000000 include an acrylic resin (a 1-1) obtained by polymerizing an acrylic polymer (a 11) having a functional group reactive with a group of another compound and an energy ray-curable compound (a 12) having an energy ray-curable group such as a group reactive with the functional group and an energy ray-curable double bond.
Examples of the functional group that can react with a group of another compound include a hydroxyl group, a carboxyl group, an amino group, a substituted amino group (a group in which one or two hydrogen atoms of an amino group are replaced with groups other than a hydrogen atom), an epoxy group, and the like. Among them, the functional group is preferably a group other than a carboxyl group from the point of preventing corrosion of a circuit of a semiconductor wafer, a semiconductor chip, or the like.
Wherein preferably the functional group is a hydroxyl group.
Acrylic Polymer having functional group (a 11)
Examples of the acrylic polymer (a 11) having a functional group include a polymer obtained by copolymerizing an acrylic monomer having a functional group with an acrylic monomer having no functional group, and a polymer obtained by copolymerizing a monomer other than an acrylic monomer (a non-acrylic monomer) other than these monomers.
The acrylic polymer (a 11) may be a random copolymer or a block copolymer.
Examples of the acrylic monomer having the functional group include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, a substituted amino group-containing monomer, and an epoxy group-containing monomer.
Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylates such as hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate; and non (meth) acrylic unsaturated alcohols (unsaturated alcohols having no (meth) acryl skeleton) such as vinyl alcohol and allyl alcohol.
Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth) acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as fumaric acid, itaconic acid, maleic acid, and citraconic acid; anhydrides of the ethylenically unsaturated dicarboxylic acids; and carboxyalkyl (meth) acrylates such as 2-carboxyethyl methacrylate.
Preferably, the acrylic monomer having the functional group is a hydroxyl group-containing monomer or a carboxyl group-containing monomer, more preferably a hydroxyl group-containing monomer.
The acrylic monomer having the functional group constituting the acrylic polymer (a 11) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
Examples of the acrylic monomer having no functional group include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, myristyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, palmityl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, and stearyl (meth) acrylate The alkyl group constituting the alkyl ester is a chain-structured alkyl (meth) acrylate having 1 to 18 carbon atoms, or the like.
Examples of the acrylic monomer having no functional group include alkoxyalkyl group-containing (meth) acrylates such as methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and the like; (meth) acrylic esters having an aromatic group, including aryl (meth) acrylates such as phenyl (meth) acrylate; non-crosslinking (meth) acrylamides and derivatives thereof; and (meth) acrylic acid esters having a non-crosslinkable tertiary amino group such as N, N-dimethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl (meth) acrylate.
The acrylic monomer not having the functional group constituting the acrylic polymer (a 11) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
Examples of the non-acrylic monomer include olefins such as ethylene and norbornene; vinyl acetate; styrene, and the like.
The non-acrylic monomer constituting the acrylic polymer (a 11) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the acrylic polymer (a 11), the proportion (content) of the amount of the structural unit derived from the acrylic monomer having the functional group is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass, and particularly preferably 3 to 30% by mass, relative to the total amount of the structural units constituting the polymer. By setting the ratio to such a range, the curing degree of the protective film can be easily adjusted to a preferable range by the content of the energy ray-curable group in the acrylic resin (a 1-1) obtained by copolymerizing the acrylic polymer (a 11) with the energy ray-curable compound (a 12).
The acrylic polymer (a 11) constituting the acrylic resin (a 1-1) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
The content of the acrylic resin (a 1-1) in the protective film-forming composition (IV-1) is preferably 1 to 40% by mass, more preferably 2 to 30% by mass, and particularly preferably 3 to 20% by mass.
Energy ray-curable Compound (a 12)
The energy ray-curable compound (a 12) preferably has one or more groups selected from the group consisting of isocyanate groups, epoxy groups, and carboxyl groups as groups that can react with functional groups of the acrylic polymer (a 11), and more preferably has isocyanate groups as the groups. For example, when the energy ray-curable compound (a 12) has an isocyanate group as the group, the isocyanate group easily reacts with the hydroxyl group of the acrylic polymer (a 11) having a hydroxyl group as the functional group.
The energy ray-curable compound (a 12) preferably has 1 to 5 energy ray-curable groups in 1 molecule, more preferably 1 to 3 energy ray-curable groups.
Examples of the energy ray-curable compound (a 12) include 2-methacryloyloxyethyl isocyanate, m-isopropenyl- α, α -dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1- (bisacryloxymethyl) ethyl isocyanate;
An acryl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth) acrylate;
and acryl monoisocyanate compounds obtained by reacting a diisocyanate compound or polyisocyanate compound, a polyol compound, and hydroxyethyl (meth) acrylate.
Among them, the energy ray-curable compound (a 12) is preferably 2-methacryloyloxyethyl isocyanate.
The energy ray-curable compound (a 12) constituting the acrylic resin (a 1-1) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
In the acrylic resin (a 1-1), the ratio of the content of the energy ray-curable group derived from the energy ray-curable compound (a 12) to the content of the functional group derived from the acrylic polymer (a 11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. By making the ratio of the content in such a range, the adhesive force of the protective film formed by curing becomes larger. In addition, when the energy ray-curable compound (a 12) is a monofunctional (having 1 of the groups in 1 molecule), the upper limit of the content ratio is 100 mol%, and when the energy ray-curable compound (a 12) is a polyfunctional (having 2 or more of the groups in 1 molecule), the upper limit of the content ratio is sometimes more than 100 mol%.
The weight average molecular weight (Mw) of the polymer (a 1) is preferably 100000 ~ 2000000, more preferably 300000 ~ 1500000.
When the polymer (a 1) is a substance in which at least a part thereof is crosslinked by the crosslinking agent (f), the polymer (a 1) may be a polymer in which a monomer having a group reactive with the crosslinking agent (f) is copolymerized and crosslinked at a group reactive with the crosslinking agent (f), or a polymer in which a group reactive with the functional group is crosslinked from the energy ray-curable compound (a 12), not being any of the above monomers described as monomers constituting the acrylic polymer (a 11).
The polymer (a 1) contained in the composition (IV-1) for forming a protective film and the film for forming a protective film may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
(Compound (a 2) having an energy ray-curable group and having a molecular weight of 100 to 80000)
The energy ray-curable group in the compound (a 2) having an energy ray-curable group and a molecular weight of 100 to 80000 includes a group containing an energy ray-curable double bond, and preferable groups include a (meth) acryloyl group, a vinyl group, and the like.
The compound (a 2) is not particularly limited as long as the above conditions are satisfied, and examples thereof include low molecular weight compounds having an energy ray-curable group, epoxy resins having an energy ray-curable group, phenol resins having an energy ray-curable group, and the like.
The low molecular weight compound having an energy ray-curable group in the compound (a 2) includes, for example, a polyfunctional monomer or oligomer, and the like, and an acrylic compound having a (meth) acryloyl group is preferable.
As the above-mentioned acrylic acid ester-based compound, examples thereof include 2-hydroxy-3- (meth) acryloxypropyl methacrylate, polyethylene glycol di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, 2-bis [4- ((meth) acryloxypolyethoxy) phenyl ] propane, ethoxylated bisphenol A di (meth) acrylate, 2-bis [4- ((meth) acryloxydiethoxy) phenyl ] propane, 9-bis [4- (2- (meth) acryloxyethoxy) phenyl ] fluorene, 2-bis [4- ((meth) acryloxypolypropoxy) phenyl ] propane, tricyclodecanedimethanol di (meth) acrylate (tricyclodecane dimethylol di (meth) acrylate), 1, 10-decane diol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, difunctional (meth) acrylates such as 2, 2-bis [4- ((meth) acryloyloxyethoxy) phenyl ] propane, neopentyl glycol di (meth) acrylate, ethoxylated polypropylene glycol di (meth) acrylate, 2-hydroxy-1, 3-di (meth) acryloyloxypropane;
Polyfunctional (meth) acrylates such as tris (2- (meth) acryloyloxyethyl) isocyanurate, epsilon-caprolactone-modified tris (2- (meth) acryloyloxyethyl) isocyanurate, ethoxylated glycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol poly (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like;
multifunctional (meth) acrylate oligomers such as urethane (meth) acrylate oligomers, and the like.
As the epoxy resin having an energy ray-curable group or the phenol resin having an energy ray-curable group in the compound (a 2), for example, the resin described in paragraph [0043] or the like of "japanese patent application laid-open No. 2013-194102" can be used. Such a resin also corresponds to a resin constituting the thermosetting component (h) described later, but in the present invention, this is regarded as the compound (a 2).
The weight average molecular weight of the compound (a 2) is preferably 100 to 30000, more preferably 300 to 10000.
The protective film-forming composition (IV-1) and the compound (a 2) contained in the protective film-forming film may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
[ Polymer (b) having no energy ray-curable group ]
When the composition (IV-1) for forming a protective film and the film for forming a protective film contain the compound (a 2) as the energy ray-curable component (a), it is preferable that the composition further contain a polymer (b) having no energy ray-curable group.
The polymer (b) may be a substance crosslinked at least partially with the crosslinking agent (f), or may be a substance not crosslinked.
Examples of the polymer (b) having no energy ray-curable group include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber resins, acrylic urethane resins, polyvinyl alcohol (PVA), butyral resins, polyester urethane resins, and the like.
Among them, the polymer (b) is preferably an acrylic polymer (hereinafter, abbreviated as "acrylic polymer (b-1)").
The acrylic polymer (b-1) may be a known acrylic polymer, and may be, for example, a homopolymer of one acrylic monomer, a copolymer of two or more acrylic monomers, or a copolymer of one or more acrylic monomers and one or more monomers other than acrylic monomers (non-acrylic monomers).
Examples of the acrylic monomer constituting the acrylic polymer (b-1) include alkyl (meth) acrylates, (meth) acrylates having a cyclic skeleton, glycidyl group-containing (meth) acrylates, hydroxyl group-containing (meth) acrylates, and substituted amino group-containing (meth) acrylates. Here, "substituted amino group" is the same as that described hereinabove.
Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, myristyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, palmityl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, and stearyl (meth) acrylate The alkyl group constituting the alkyl ester is a chain-structured alkyl (meth) acrylate having 1 to 18 carbon atoms, or the like.
Examples of the (meth) acrylic acid ester having a cyclic skeleton include cycloalkyl (meth) acrylates such as isobornyl (meth) acrylate and dicyclopentyl (meth) acrylate;
aralkyl (meth) acrylates such as benzyl (meth) acrylate;
cycloalkenyl (meth) acrylates such as dicyclopentenyl (meth) acrylate;
And cycloalkenyloxyalkyl (meth) acrylates such as dicyclopentenyloxyethyl (meth) acrylate.
Examples of the glycidyl group-containing (meth) acrylate include glycidyl (meth) acrylate.
Examples of the hydroxyl group-containing (meth) acrylate include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.
Examples of the substituted amino group-containing (meth) acrylate include N-methylaminoethyl (meth) acrylate and the like.
Examples of the non-acrylic monomer constituting the acrylic polymer (b-1) include olefins such as ethylene and norbornene; vinyl acetate; styrene, and the like.
Examples of the polymer (b) having no energy ray-curable group, at least a part of which is crosslinked by the crosslinking agent (f), include polymers obtained by reacting a reactive functional group in the polymer (b) with the crosslinking agent (f).
The reactive functional group is not particularly limited, as long as it is appropriately selected according to the kind of the crosslinking agent (f) and the like. For example, when the crosslinking agent (f) is a polyisocyanate compound, examples of the reactive functional group include a hydroxyl group, a carboxyl group, an amino group, and the like, and among these, a hydroxyl group having high reactivity with an isocyanate group is preferable. When the crosslinking agent (f) is an epoxy compound, examples of the reactive functional group include a carboxyl group, an amino group, an amide group, and the like, and among these, a carboxyl group having high reactivity with an epoxy group is preferable. However, in terms of preventing corrosion of the circuit of the semiconductor wafer or the semiconductor chip, it is preferable that the functional group is a group other than a carboxyl group.
Examples of the polymer (b) having the reactive functional group and not having an energy ray-curable group include a polymer obtained by polymerizing a monomer having at least the reactive functional group. In the case of the acrylic polymer (b-1), any one or both of the acrylic monomer and the non-acrylic monomer, which are exemplified as the monomers constituting the acrylic polymer (b-1), may be used. Examples of the polymer (b) having a hydroxyl group as a reactive functional group include a polymer obtained by polymerizing a hydroxyl group-containing (meth) acrylate, and other examples of the polymer (b) include a polymer obtained by polymerizing a monomer obtained by substituting the reactive functional group with one or more hydrogen atoms in the acrylic monomer or the non-acrylic monomer listed above.
In the polymer (b) having a reactive functional group, the proportion (content) of the amount of the structural unit derived from the monomer having a reactive functional group to the total amount of the structural units constituting the polymer (b) is preferably 1 to 25% by mass, more preferably 2 to 20% by mass. By setting the ratio to such a range, the degree of crosslinking in the polymer (b) becomes a more preferable range.
The weight average molecular weight (Mw) of the polymer (b) having no energy ray-curable group is preferably 10000 ~ 2000000, more preferably 100000 ~ 1500000, from the viewpoint of better film-forming property of the composition (IV-1) for forming a protective film.
The composition (IV-1) for forming a protective film and the polymer (b) having no energy ray-curable group contained in the film for forming a protective film may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
The composition (IV-1) for forming a protective film includes a composition for forming a protective film containing either one or both of the polymer (a 1) and the compound (a 2). When the compound (a 2) is contained, the protective film-forming composition (IV-1) preferably further contains a polymer (b) having no energy ray-curable group, and in this case, the composition further preferably further contains the compound (a 1). The composition (IV-1) for forming a protective film may not contain the compound (a 2) but may contain the polymer (a 1) and the polymer (b) having no energy ray-curable group.
When the composition (IV-1) for forming a protective film contains the polymer (a 1), the compound (a 2) and the polymer (b) having no energy ray-curable group, the content of the compound (a 2) is preferably 10 to 400 parts by mass, more preferably 30 to 350 parts by mass, relative to 100 parts by mass of the total content of the polymer (a 1) and the polymer (b) having no energy ray-curable group in the composition (IV-1) for forming a protective film.
In the composition (IV-1) for forming a protective film, the ratio of the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group (i.e., the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group) in the film for forming a protective film) to the total content of the components other than the solvent is preferably 5 to 90 mass%, more preferably 10 to 80 mass%, particularly preferably 15 to 70 mass%, and for example, may be any one of 15 to 60 mass% and 15 to 50 mass%. When the ratio of the total content is in such a range, the energy ray curability of the protective film forming film is further improved.
When the composition (IV-1) for forming a protective film contains the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group, the content of the polymer (b) is preferably 3 to 160 parts by mass, more preferably 6 to 130 parts by mass, per 100 parts by mass of the content of the energy ray-curable component (a) in the composition (IV-1) for forming a protective film and the film for forming a protective film. By setting the content of the polymer (b) to such a range, the energy ray curability of the protective film-forming film becomes more excellent.
The composition (IV-1) for forming a protective film may contain, in addition to the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group, one or more selected from the group consisting of a photopolymerization initiator (c), a filler (d), a coupling agent (e), a crosslinking agent (f), a colorant (g), a thermosetting component (h), a curing accelerator (i) and a general-purpose additive (z), depending on the purpose. For example, by using the composition (IV-1) for forming a protective film containing the energy ray-curable component (a) and the thermosetting component (h), the adhesion of the formed film for forming a protective film to an adherend is improved by heating, and the strength of the protective film formed from the film for forming a protective film is also improved.
[ Photopolymerization initiator (c) ]
Examples of the photopolymerization initiator (c) include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal; acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-dimethoxy-1, 2-diphenylethan-1-one, and the like; acylphosphine oxide compounds such as phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide and 2,4, 6-trimethylbenzoyl diphenyl phosphine oxide; sulfur compounds such as benzyl phenyl sulfide and tetramethylthiuram monosulfide; alpha-ketol compounds such as 1-hydroxycyclohexyl phenyl ketone; azo compounds such as azobisisobutyronitrile; a titanocene compound such as titanocene; thioxanthone compounds such as thioxanthone; benzophenone compounds such as benzophenone, 2- (dimethylamino) -1- (4-morpholinophenyl) -2-benzyl-1-butanone, 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] ethanone 1- (O-acetyloxime); a peroxide compound; diketone compounds such as diacetyl; benzil; a dibenzoyl group; 2, 4-diethylthioxanthone; 1, 2-diphenylmethane; 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] propanone; 2-chloroanthraquinone, and the like.
Further, as the photopolymerization initiator (c), for example, quinone compounds such as 1-chloroanthraquinone can be used; amine and the like.
The photopolymerization initiator (c) contained in the protective film-forming composition (IV-1) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
When the photopolymerization initiator (c) is used, the content of the photopolymerization initiator (c) is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and particularly preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the content of the energy ray-curable component (a) in the composition (IV-1) for forming a protective film.
[ Filler (d) ]
By containing the filler (d) in the protective film-forming film, the thermal expansion coefficient of the protective film obtained by curing the protective film-forming film can be easily adjusted. Further, by optimizing the coefficient of thermal expansion with respect to the object to be formed of the protective film, the reliability of the package obtained by using the composite sheet for forming the protective film is further improved. Further, by containing the filler (d) in the protective film forming film, the moisture absorption rate of the protective film can be reduced or the heat radiation property can be improved.
As the filler (d), for example, a filler composed of a heat conductive material can be cited.
The filler (d) may be any of an organic filler and an inorganic filler, and is preferably an inorganic filler.
Preferable examples of the inorganic filler include powders such as silica, alumina, talc, calcium carbonate, titanium white, red lead, silicon carbide, and boron nitride; beads obtained by spheroidizing these inorganic fillers; surface modifications of these inorganic filler materials; single crystal fibers of these inorganic filler materials; glass fiber, and the like.
Among them, the inorganic filler is preferably silica or alumina.
The average particle diameter of the filler (d) is not particularly limited, but is preferably 0.01 to 20. Mu.m, more preferably 0.1 to 15. Mu.m, particularly preferably 0.3 to 10. Mu.m. By setting the average particle diameter of the filler (d) to such a range, it is possible to suppress a decrease in light transmittance of the protective film while maintaining the adhesion of the protective film to the object to be formed.
In addition, unless otherwise specified, the "average particle diameter" in the present specification refers to a value of the particle diameter (D 50) at which the cumulative value is 50% in the particle size distribution curve obtained by the laser diffraction scattering method.
The composition (IV-1) for forming a protective film and the filler (d) contained in the film for forming a protective film may be one kind only or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
When the filler (d) is used, the content of the filler (d) (i.e., the content of the filler (d) in the protective film-forming composition (IV-1)) is preferably 5 to 83% by mass, more preferably 7 to 78% by mass, and may be, for example, any one of 10 to 78% by mass, 25 to 78% by mass, 40 to 78% by mass, and 50 to 78% by mass, based on the total content of all components except the solvent. By setting the content of the filler (d) to such a range, the adjustment of the thermal expansion coefficient described above becomes easier.
[ Coupling agent (e) ]
By using a substance having a functional group reactive with an inorganic compound or an organic compound as the coupling agent (e), the adhesiveness and the adhesiveness of the protective film-forming film to an adherend can be improved. In addition, by using the coupling agent (e), the water resistance of the protective film obtained by curing the protective film-forming film is improved without impairing the heat resistance.
The coupling agent (e) is preferably a compound having a functional group reactive with a functional group of the energy ray-curable component (a), the polymer (b) having no energy ray-curable group, or the like, and more preferably a silane coupling agent.
Preferable examples of the silane coupling agent include 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyl diethoxysilane, 3-glycidoxypropyl triethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, 3- (2-aminoethylamino) propyl methyl diethoxysilane, 3- (phenylamino) propyl trimethoxysilane, 3-anilinopropyl trimethoxysilane, 3-ureidopropyl triethoxysilane, 3-mercaptopropyl trimethoxysilane, 3-mercaptopropyl methyl dimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfide, methyltrimethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazole silane.
The protective film-forming composition (IV-1) and the coupling agent (e) contained in the protective film-forming film may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
When the coupling agent (e) is used, the content of the coupling agent (e) is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group in the protective film-forming composition (IV-1) and the protective film-forming film. By setting the content of the coupling agent (e) to the lower limit value or more, the effect of using the coupling agent (e) such as an improvement in dispersibility of the filler (d) in the resin, an improvement in adhesiveness between the protective film-forming film and the adherend, and the like can be obtained more remarkably. Further, by setting the content of the coupling agent (e) to the upper limit value or less, the occurrence of degassing can be further suppressed.
[ Cross-linking agent (f) ]
The initial adhesion and cohesion of the film for forming a protective film can be adjusted by crosslinking the energy ray-curable component (a) or the polymer (b) having no energy ray-curable group with the crosslinking agent (f).
Examples of the crosslinking agent (f) include an organic polyisocyanate compound, an organic polyimide compound, a metal chelate crosslinking agent (a crosslinking agent having a metal chelate structure), an aziridine crosslinking agent (a crosslinking agent having an aziridine group), and the like.
Examples of the organic polyisocyanate compound include aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, and alicyclic polyisocyanate compounds (hereinafter, these compounds may be collectively abbreviated as "aromatic polyisocyanate compounds and the like"); a trimer, isocyanurate, or adduct of the aromatic polyisocyanate compound; and a terminal isocyanate urethane prepolymer obtained by reacting the aromatic polyisocyanate compound or the like with a polyol compound. The "adduct" refers to a reactant of the aromatic polyisocyanate compound, aliphatic polyisocyanate compound or alicyclic polyisocyanate compound with a low molecular active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil. Examples of the adduct include a xylylene diisocyanate adduct of trimethylolpropane, which will be described later. The term "terminal isocyanate urethane prepolymer" refers to a prepolymer having a urethane bond and an isocyanate group at a terminal part of a molecule.
More specifically, examples of the organic polyisocyanate compound include 2, 4-toluene diisocyanate; 2, 6-toluene diisocyanate; 1, 3-xylylene diisocyanate; 1, 4-xylylene diisocyanate; diphenylmethane-4, 4' -diisocyanate; diphenylmethane-2, 4' -diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4, 4' -diisocyanate; dicyclohexylmethane-2, 4' -diisocyanate; a compound in which any one or two or more of toluene diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are added to all or a part of hydroxyl groups of a polyhydric alcohol such as trimethylolpropane; lysine diisocyanate, and the like.
Examples of the organic polyimine compound include N, N ' -diphenylmethane-4, 4' -bis (1-aziridinecarboxamide), trimethylolpropane-tris- β -aziridinyl propionate, tetramethylolmethane-tris- β -aziridinylpropionate, and N, N ' -toluene-2, 4-bis (1-aziridinyl carboxamide) triethylenemelamine.
When the organic polyisocyanate compound is used as the crosslinking agent (f), a hydroxyl group-containing polymer is preferably used as the energy ray-curable component (a) or the polymer (b) having no energy ray-curable group. When the crosslinking agent (f) has an isocyanate group, the energy ray-curable component (a), or the polymer (b) having no energy ray-curable group has a hydroxyl group, the crosslinked structure can be easily introduced into the film for forming a protective film by the reaction of the crosslinking agent (f) with the energy ray-curable component (a) or the polymer (b) having no energy ray-curable group.
The composition (IV-1) for forming a protective film and the crosslinking agent (f) contained in the film for forming a protective film may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
When the crosslinking agent (f) is used, the content of the crosslinking agent (f) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group in the protective film-forming composition (IV-1). By making the content of the crosslinking agent (f) be the lower limit value or more, the effect produced by using the crosslinking agent (f) can be obtained more remarkably. Further, by setting the content of the crosslinking agent (f) to the upper limit value or less, excessive use of the crosslinking agent (f) can be suppressed.
[ Colorant (g) ]
Examples of the colorant (g) include known colorants such as inorganic pigments, organic pigments, and organic dyes.
Examples of the organic pigment and the organic dye include amines(Aminium) pigments, cyanine pigments, merocyanine pigments, croconium (croconium) pigments, squaraine (squarylium) pigments, gan Julan/>(Azulenium) pigmenting, polymethine pigmenting, naphthoquinone pigmenting, pyran/>A pigment, phthalocyanine pigment, naphthalocyanine pigment, naphthalenide (naphtholactam) pigment, azo pigment, condensed azo pigment, indigo pigment, perinone (perinone) pigment, perylene pigment, dioxazine pigment, quinacridone pigment, isoindolinone pigment, quinophthalone pigment, pyrrole pigment, thioindigo pigment, metal complex pigment (metal complex salt dye), dithiol metal complex pigment, indophenol pigment, triallylmethane pigment, anthraquinone pigment, naphthol pigment, azone pigment, benzimidazolone pigment, pyranthrone pigment, and petrolatum (threne) pigment.
Examples of the inorganic pigment include carbon black, cobalt-based pigment, iron-based pigment, chromium-based pigment, titanium-based pigment, vanadium-based pigment, zirconium-based pigment, molybdenum-based pigment, ruthenium-based pigment, platinum-based pigment, ITO (indium tin oxide) based pigment, ATO (antimony tin oxide) based pigment, and the like.
The composition (IV-1) for forming a protective film and the colorant (g) contained in the film for forming a protective film may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
When the colorant (g) is used, the content of the colorant (g) in the protective film-forming film may be appropriately adjusted according to the purpose. For example, the protective film may be printed by laser irradiation, and the printing visibility may be adjusted by adjusting the content of the colorant (g) in the protective film-forming film and adjusting the light transmittance of the protective film. In this case, in the composition (IV-1) for forming a protective film, the content of the colorant (g) (i.e., the content of the colorant (g) in the film for forming a protective film) is preferably 0.1 to 10% by mass, more preferably 0.4 to 7.5% by mass, and particularly preferably 0.8 to 5% by mass, based on the total content of all components except the solvent. By making the content of the colorant (g) be the lower limit value or more, the effect produced by using the colorant (g) can be obtained more remarkably. Further, by setting the content of the colorant (g) to the upper limit value or less, excessive use of the colorant (g) can be suppressed.
[ Thermosetting component (h) ]
The thermosetting component (h) contained in the composition (IV-1) for forming a protective film and the film for forming a protective film may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
Examples of the thermosetting component (h) include epoxy thermosetting resins, thermosetting polyimides, polyurethanes, unsaturated polyesters, silicone resins, and the like, and epoxy thermosetting resins are preferable.
(Epoxy thermosetting resin)
The epoxy thermosetting resin is composed of an epoxy resin (h 1) and a thermosetting agent (h 2).
The epoxy thermosetting resin contained in the composition (IV-1) for forming a protective film and the film for forming a protective film may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
Epoxy resin (h 1)
The epoxy resin (h 1) includes known epoxy resins, and examples thereof include polyfunctional epoxy resins, biphenyl compounds, bisphenol a diglycidyl ether and its hydrogenated products, o-cresol novolac epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, bisphenol a type epoxy resins, bisphenol F type epoxy resins, and epoxy compounds having a double function or more such as phenylene skeleton type epoxy resins.
As the epoxy resin (h 1), an epoxy resin having an unsaturated hydrocarbon group can be used. The epoxy resin having an unsaturated hydrocarbon group has a higher compatibility with the acrylic resin than the epoxy resin having no unsaturated hydrocarbon group. Therefore, by using an epoxy resin having an unsaturated hydrocarbon group, the reliability of the package obtained by using the composite sheet for forming a protective film is improved.
Examples of the epoxy resin having an unsaturated hydrocarbon group include a compound in which a part of the epoxy groups of a multifunctional epoxy resin is converted into groups having an unsaturated hydrocarbon group. Such a compound can be obtained, for example, by subjecting (meth) acrylic acid or a derivative thereof to an addition reaction with an epoxy group.
Examples of the epoxy resin having an unsaturated hydrocarbon group include a compound in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring or the like constituting the epoxy resin.
The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include an ethylene (vinyl) group, a 2-propenyl (allyl) group, a (meth) acryl group, a (meth) acrylamide group, and the like, and acryl groups are preferable.
The number average molecular weight of the epoxy resin (h 1) is not particularly limited, and is preferably 300 to 30000, more preferably 400 to 10000, particularly preferably 500 to 3000, from the viewpoint of curability of the film for forming a protective film, and strength and heat resistance of the protective film.
The epoxy equivalent of the epoxy resin (h 1) is preferably 100 to 1000g/eq, more preferably 150 to 800g/eq.
The epoxy resin (h 1) may be used alone or in combination of two or more, and when two or more are used at the same time, the combination and ratio thereof may be arbitrarily selected.
Thermosetting agent (h 2)
The thermosetting agent (h 2) functions as a curing agent for the epoxy resin (h 1).
Examples of the thermosetting agent (h 2) include compounds having two or more functional groups capable of reacting with an epoxy group in 1 molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an acid group, and the functional group is preferably a phenolic hydroxyl group, an amino group, or an acid group, and more preferably a phenolic hydroxyl group or an amino group.
Examples of the phenolic curing agent having a phenolic hydroxyl group in the thermosetting agent (h 2) include polyfunctional phenol resins, biphenol, novolak-type phenol resins, dicyclopentadiene-type phenol resins, and aralkyl-phenol resins.
Examples of amine curing agents having an amino group in the heat curing agent (h 2) include dicyandiamide (hereinafter, abbreviated as "dic") and the like.
The thermosetting agent (h 2) may have an unsaturated hydrocarbon group.
Examples of the thermosetting agent (h 2) having an unsaturated hydrocarbon group include a compound in which a part of the hydroxyl groups of the phenol resin is substituted with a group having an unsaturated hydrocarbon group, a compound in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of the phenol resin, and the like.
The unsaturated hydrocarbon group in the thermosetting agent (h 2) is the same as that in the above-mentioned epoxy resin having an unsaturated hydrocarbon group.
When a phenol curing agent is used as the thermosetting agent (h 2), the thermosetting agent (h 2) is preferably a thermosetting agent having a high softening point or glass transition temperature from the point of improving the peelability of the protective film from the support sheet.
The number average molecular weight of the resin component of the thermosetting agent (h 2), for example, the polyfunctional phenol resin, the novolak phenol resin, the dicyclopentadiene phenol resin, the aralkyl phenol resin and the like is preferably 300 to 30000, more preferably 400 to 10000, and particularly preferably 500 to 3000.
The molecular weight of the non-resin component such as biphenol or dicyandiamide in the thermosetting agent (h 2) is not particularly limited, and is preferably 60 to 500, for example.
The thermosetting agent (h 2) may be used alone or in combination of two or more kinds, and when two or more kinds are used at the same time, the combination and ratio thereof may be arbitrarily selected.
When the thermosetting component (h) is used, the content of the thermosetting agent (h 2) is preferably 0.01 to 20 parts by mass per 100 parts by mass of the content of the epoxy resin (h 1) in the protective film-forming composition (IV-1) and the protective film-forming film.
When the thermosetting component (h) is used, the content of the thermosetting component (h) (for example, the total content of the epoxy resin (h 1) and the thermosetting agent (h 2)) is preferably 1 to 500 parts by mass per 100 parts by mass of the content of the polymer (b) having no energy ray-curable group in the composition (IV-1) for forming a protective film and the film for forming a protective film.
[ Curing accelerator (i) ]
The curing accelerator (i) is a component for adjusting the curing speed of the film for forming a protective film.
Examples of the curing accelerator (i) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol and tris (dimethylaminomethyl) phenol, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole and 2-phenyl-4, 5-dimethylol imidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which 1 or more hydrogen atoms are substituted with groups other than hydrogen atoms), tributylphosphine, diphenylphosphine and triphenylphosphine (phosphines in which 1 or more hydrogen atoms are substituted with organic groups), tetraphenylphosphineTetraphenylborates such as tetraphenylborates and triphenylphosphine tetraphenylborates.
The curing accelerator (i) may be used alone or in combination of two or more, and when two or more are used at the same time, the combination and ratio thereof may be arbitrarily selected.
When the curing accelerator (i) is used, the content of the curing accelerator (i) in the composition (IV-1) for forming a protective film and the film for forming a protective film is not particularly limited, and may be appropriately selected according to the components used simultaneously.
[ General additive (z) ]
The general-purpose additive (z) may be a known additive, and may be arbitrarily selected according to the purpose, and is not particularly limited, and examples of preferable additives include plasticizers, antistatic agents, antioxidants, and capturing agents (GETTERING AGENT).
The composition (IV-1) for forming a protective film and the general-purpose additive (z) contained in the film for forming a protective film may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof may be arbitrarily selected.
When the general-purpose additive (z) is used, the content of the composition (IV-1) for forming a protective film and the general-purpose additive (z) for forming a protective film is not particularly limited, and may be appropriately selected according to the purpose.
[ Solvent ]
The protective film-forming composition (IV-1) preferably further contains a solvent. The solvent-containing composition (IV-1) for forming a protective film is excellent in handleability.
The solvent is not particularly limited, and examples of the preferable solvent include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone.
The solvent contained in the protective film-forming composition (IV-1) may be one or two or more, and when two or more are used, the combination and ratio thereof may be arbitrarily selected.
The solvent contained in the composition (IV-1) for forming a protective film is preferably methyl ethyl ketone, toluene, ethyl acetate, or the like, from the viewpoint of enabling more uniform mixing of the components contained in the composition (IV-1) for forming a protective film.
Method for producing composition for forming protective film
The composition for forming a protective film such as the composition (IV-1) for forming a protective film can be obtained by blending the components for constituting the composition.
The order of addition in blending the components is not particularly limited, and two or more components may be added simultaneously.
When a solvent is used, the solvent may be mixed with any blend component other than the solvent to pre-dilute the blend component, or the solvent may be mixed with any blend component other than the solvent to use the blend component without pre-diluting the blend component.
The method of mixing the components at the time of blending is not particularly limited, and may be appropriately selected from the following known methods: a method of mixing by rotating a stirrer, stirring blades, or the like; a method of mixing using a stirrer; and a method of mixing by applying ultrasonic waves.
The temperature and time at the time of adding and mixing the components are not particularly limited as long as the components to be blended are not degraded, and the temperature is preferably 15 to 30 ℃.
As a composite sheet which is attached to the back surface of a semiconductor wafer or a semiconductor chip opposite to a circuit surface and which has a layer exhibiting adhesiveness on a support sheet, the same composite sheet for forming a protective film of the present invention, there is a dicing die bonding sheet (DICING DIE bonding sheet).
However, after the adhesive layer provided in the dicing die bonding sheet is picked up from the supporting sheet together with the semiconductor chip, the adhesive layer functions as an adhesive for attaching the semiconductor chip to a substrate, a lead frame, or other semiconductor chips or the like. On the other hand, the protective film forming film in the composite sheet for forming a protective film of the present invention is the same as the adhesive layer in that it is picked up together with the semiconductor chip from the supporting sheet, but it finally becomes a protective film by curing, and has the function of protecting the back surface of the attached semiconductor chip. As described above, the film for forming a protective film of the present invention is different from the use of the adhesive layer in the dicing die bonding sheet, and the intended performance is certainly different. In general, the film for forming a protective film tends to be hard and difficult to pick up as compared with the adhesive layer in the dicing die bonding sheet, and this also reflects the difference in the above-described applications. Therefore, it is generally difficult to directly transfer the adhesive layer in the dicing die bonding sheet as the protective film forming film in the composite sheet for protective film formation. The composite sheet for forming a protective film of the present invention is a composite sheet for forming a protective film which has excellent suitability for picking up a semiconductor chip with a protective film, which has not been conventionally known, as a composite sheet having a film for forming a protective film having energy ray curability.
Method for producing composite sheet for forming protective film
The composite sheet for forming a protective film of the present invention can be produced by sequentially laminating the above layers so that the above layers have a corresponding positional relationship. The method of forming each layer is the same as described hereinabove.
For example, in the case of producing a support sheet, when an adhesive layer is laminated on a substrate, the adhesive composition may be applied to the substrate and dried as necessary.
On the other hand, for example, when a protective film forming film is further laminated on an adhesive layer laminated on a substrate, the protective film forming composition may be applied on the adhesive layer and the protective film forming film may be directly formed. The same method can be used for the layers other than the protective film forming film, and the layers can be laminated on the adhesive layer using the composition for forming the layers. In this way, when a laminated structure of two continuous layers is formed using an arbitrary composition, a composition may be further coated on a layer formed of the composition to form a new layer. Among them, it is preferable to form a layer stacked later of the above two layers on another release film in advance by using the composition, and to form a laminated structure of two continuous layers by bonding an exposed surface of the formed layer on the opposite side to the side in contact with the release film and an exposed surface of the formed other layer. In this case, the composition is preferably applied to the release treated surface of the release film. After the laminated structure is formed, the release film may be removed as needed.
For example, when a composite sheet for forming a protective film (a support sheet is a composite sheet for forming a protective film of a laminate of a base material and an adhesive layer) obtained by laminating an adhesive layer on a base material and laminating a film for forming a protective film on the adhesive layer is produced, the adhesive layer is laminated on the base material by applying the adhesive composition to the base material and drying it as needed, and the protective film-forming composition is further applied to a release film and drying it as needed, thereby forming a film for forming a protective film on the release film. Then, the exposed surface of the protective film forming film is bonded to the exposed surface of the adhesive layer laminated on the substrate, and the protective film forming film is laminated on the adhesive layer, whereby a composite sheet for forming a protective film can be obtained.
In addition, when the adhesive layer is laminated on the substrate, as described above, instead of the method of applying the adhesive composition to the substrate, the adhesive composition is applied to the release film and dried as necessary, thereby forming the adhesive layer on the release film, and the exposed surface of the layer is bonded to the surface of one side of the substrate, whereby the adhesive layer can be laminated on the substrate.
In any method, the release film may be removed at any timing after the target laminated structure is formed.
As described above, the layers constituting the composite sheet for forming a protective film other than the base material may be formed on the release film in advance and laminated on the surface of the target layer, and thus the composite sheet for forming a protective film may be produced by appropriately selecting the layers in such a process as needed.
The composite sheet for forming a protective film is usually stored in a state in which a release film is bonded to the surface of the outermost layer (e.g., protective film forming film) on the opposite side of the support sheet. Therefore, even when the composition for forming the outermost layer, such as the composition for forming a protective film, is applied onto a release film (preferably, a release treated surface thereof) and dried as necessary, the outermost layer is formed on the release film, and other layers are laminated on an exposed surface of the layer on the opposite side to the side in contact with the release film by any of the above methods, and the release film is bonded without being removed, the composite sheet for forming a protective film can be obtained.
Method for using composite sheet for forming protective film
The composite sheet for forming a protective film of the present invention can be used by the following method, for example.
That is, the protective film forming composite sheet is attached to the back surface (surface opposite to the electrode forming surface) of the semiconductor wafer through the protective film forming film. Then, the protective film is formed by irradiating the protective film-forming film with energy rays and curing the protective film-forming film. Then, the semiconductor wafer is divided together with the protective film by dicing, and semiconductor chips are manufactured. Then, the semiconductor chip is separated and picked up from the supporting sheet in a state where the protective film is attached (i.e., as a semiconductor chip with a protective film).
Then, the semiconductor chip of the obtained semiconductor chip with the protective film is flip-chip connected to the circuit surface of the substrate by the same method as the conventional method, and then a semiconductor package is manufactured. Then, using the semiconductor package, a target semiconductor device may be fabricated.
The case where the protective film is formed by curing the protective film-forming film and then cutting the film is described here, but when the composite sheet for protective film formation of the present invention is used, the order of performing these steps may be reversed. That is, after the composite sheet for forming the protective film is attached to the back surface of the semiconductor wafer, the semiconductor wafer is divided by dicing together with the film for forming the protective film, thereby producing the semiconductor chips. Then, the divided protective film forming film is irradiated with energy rays, and the protective film forming film is cured to form a protective film. Then, the semiconductor chip with the protective film is separated from the support sheet and picked up as described above, thereby producing the target semiconductor device.
Examples
Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the examples shown below.
The components used in the preparation of the composition for forming a protective film are shown below.
Energy ray-curable component
(A2) -1: tricyclodecane dimethylol diacrylate (Nippon Kayaku Co., ltd. "KAYARAD R-684", difunctional ultraviolet curable compound, molecular weight 304)
Polymers without energy-ray-curable groups
(B) -1: acrylic polymer (weight average molecular weight 300000, glass transition temperature-1 ℃ C.) (obtained by copolymerizing butyl acrylate (hereinafter abbreviated as "BA") (10 parts by mass), methyl acrylate (hereinafter abbreviated as "MA") (70 parts by mass), glycidyl methacrylate (hereinafter abbreviated as "GMA") (5 parts by mass), and 2-hydroxyethyl acrylate (hereinafter abbreviated as "HEA") (15 parts by mass)
(B) -2: acrylic Polymer (weight average molecular weight 37000glass transition temperature 6 ℃ C.) copolymerized with MA (85 parts by mass) and HEA (15 parts by mass)
Photopolymerization initiator
(C) -1:2- (dimethylamino) -1- (4-morpholinophenyl) -2-benzyl-1-butanone (Irgacure (registered trademark) 369 manufactured by BASF corporation)
(C) -2:1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] ethanone 1- (O-acetyloxime) (Irgacure (registered trademark) OXE02 manufactured by BASF corporation)
Filler material
(D) -1: silica filler (fused silica filler, average particle size 8 μm)
(D) -2: spherical silica filler (ADMATECHS Co., ltd. "SC2050MA", average particle size 0.5 μm)
Coupling agent
(E) -1: 3-methacryloxypropyl trimethoxysilane (Shin-Etsu Chemical Co., ltd. "KBM-503", silane coupling agent)
(E) -2: 3-aminopropyl trimethoxysilane (Unicar industries Co., ltd., "A-1110", silane coupling agent)
Coloring agent
(G) -1: 32 parts by mass of a phthalocyanine blue dye (PigmentBlue 15:3), 18 parts by mass of an isoindolinone yellow dye (PigmentYellow 139), and 50 parts by mass of an anthraquinone red dye (PIGMENTRED 177) were mixed, and the mixture was colored to obtain a pigment in which the total amount of the three dyes/styrene acrylic resin amount=1/3 (mass ratio)
(G) -2: carbon black (Mitsubishi ChemicalAnalytech Co., "manufactured by Ltd.," #MA650", average particle diameter 28 nm)
Epoxy resin
(H1) -1: bisphenol A type epoxy resin (Mitsubishi Chemical corporation "jER828", epoxy equivalent 184-194 g/eq)
(H1) -2: bisphenol A type epoxy resin (Mitsubishi Chemical corporation "jER1055", 800-900 g/eq epoxy equivalent)
(H1) -3: dicyclopentadiene type epoxy resin (EPICLONHP-7200 HH manufactured by DIC CORPORATION), epoxy equivalent 255-260 g/eq)
Thermosetting agent
(H2) -1: dicyandiamide (thermally active latent curing agent, "ADEKA HARDENER EH-3636AS", manufactured by ADEKACORPORATION, active hydrogen amount 21 g/eq)
Curing accelerator
(I) -1: 2-phenyl-4, 5-dimethylol imidazole (SHIKOKU CHEMICALS CORPORATION "CUREZOL 2 PHZ-PW")
Example 1
Production of composite sheet for Forming protective film
(Preparation of composition for Forming protective film (IV-1))
The content (solid content amount, parts by mass) of the energy ray-curable component (a 2) -1, the polymer (b) -1, the photopolymerization initiator (c) -2, the filler (d) -1, the coupling agent (e) -1, and the colorant (g) -1 was dissolved or dispersed in methyl ethyl ketone so as to be the values shown in table 1, and stirred at 23 ℃, thereby preparing the composition (IV-1) for forming a protective film having a solid content concentration of 50 mass%. Note that the "-" in the column containing the component in table 1 indicates that the composition (IV-1) for forming a protective film does not contain the component.
(Preparation of adhesive composition (I-4))
A non-energy ray-curable adhesive composition (I-4) was prepared which contained an acrylic polymer (100 parts by mass, solid content) and a trifunctional xylylene diisocyanate-based crosslinking agent (manufactured by Sanjingwuta chemical Co., ltd. "TAKENATE D N") (10.7 parts by mass, solid content) and further contained methyl ethyl ketone as a solvent, the solid content concentration of which was 30% by mass. The acrylic polymer was obtained by copolymerizing 2-ethylhexyl acrylate (hereinafter abbreviated as "2 EHA") (36 parts by mass), BA (59 parts by mass), and HEA (5 parts by mass) to obtain an acrylic polymer having a weight average molecular weight of 600000.
(Production of supporting sheet)
The adhesive composition (I-4) obtained above was applied to the release treated surface of a release film (SP-PET 381031, manufactured by Lintec corporation, thickness 38 μm) obtained by releasing one side of a polyethylene terephthalate film by silicone treatment, and was dried by heating at 120℃for 2 minutes, thereby forming a non-energy ray-curable adhesive layer having a thickness of 10 μm.
Next, a polypropylene film (young's modulus 400MPa, thickness 80 μm) as a base material was bonded to the exposed surface of the adhesive layer, thereby obtaining a support sheet (10) -1 having the adhesive layer on one surface of the base material.
(Production of composite sheet for Forming protective film)
The protective film-forming composition (IV-1) obtained above was applied onto the release-treated surface of a release film (SP-PET 381031 manufactured by Lintec corporation, thickness 38 μm) obtained by releasing one side of a polyethylene terephthalate film by silicone treatment, and dried at 100 ℃ for 2 minutes, thereby producing an energy ray-curable protective film-forming film (13) -1) having a thickness of 25 μm.
Then, the release film was removed from the adhesive layer of the support sheet (10) -1 obtained as described above, and the exposed surface of the protective film forming film (13) -1 obtained as described above was bonded to the exposed surface of the adhesive layer, whereby a composite sheet for forming a protective film was produced in which the base material, the adhesive layer, the protective film forming film (13) -1, and the release film were laminated in this order in the thickness direction thereof. The composition of the obtained composite sheet for forming a protective film is shown in table 2.
Evaluation of composite sheet for Forming protective film
(Adhesion between protective film Forming film and supporting sheet)
The composite sheet for forming a protective film obtained as described above was cut into a size of 25mm×140mm, and the release film was removed from the composite sheet for forming a protective film to expose the surface of the film (13) -1 for forming a protective film as a test piece before curing. On the other hand, a material was prepared in which a double-sided adhesive tape was bonded to the surface of a support plate (70 mm. Times.150 mm) made of SUS. Then, the exposed surface of the protective film forming film (13) -1 of the test piece before curing was attached to the double-sided adhesive tape on the support plate by a laminator ("LAMIPACKER LPD3214" manufactured by FUJI CORPORATION), whereby the test piece before curing was attached to the support plate via the double-sided adhesive tape.
Then, using an "Autograph AG-IS" manufactured by a precision universal tester (Shimadzu Corporation), the support sheet (10) -1 (laminate of adhesive layer before curing and base material) was peeled off from the protective film forming film (13) -1 at a peeling angle of 180 °, a measurement temperature of 23 ℃, and a stretching speed of 300 mm/min, and a tensile test was performed to measure a load (peeling force) at this time as an adhesive force between the protective film forming film (13) -1 and the support sheet (10) -1. The following values were used as the measurement values of the load: of the measurement values obtained when the support sheet (10) -1 was peeled by a length of 100mm, each measurement value obtained when the support sheet was peeled by a length of only 10mm at the beginning and the support sheet was peeled by a length of only 10mm at the end was removed from the effective values, and the remaining values were obtained. The results are shown in Table 2.
(Adhesion between protective film and supporting sheet)
In the same manner as in the measurement of the adhesion force of the test piece before curing, a test piece before curing was produced, and the test piece before curing was attached to a support plate made of SUS via a double-sided adhesive tape.
Then, the film (13) -1 for forming a protective film was cured by irradiating the test piece before curing with ultraviolet rays under conditions of illuminance of 195mW/cm 2 and light amount of 170mJ/cm 2 using an ultraviolet irradiation apparatus (Lintec Corporation, "RAD2000 m/8"), to obtain a test piece after curing.
Then, the adhesion between the protective film and the support sheet (10) -1, which were obtained by curing the protective film-forming film (13) -1, was measured for the test piece after curing in the same manner as for the test piece before curing. The results are shown in Table 2.
(Suppression of breakage and missing of silicon chip at pickup)
The composite sheet for forming a protective film obtained above was attached to a #2000 polished surface of a 6-inch silicon wafer (thickness 100 μm) via a film (13) -1 for forming a protective film, and the sheet was further fixed to an annular frame and allowed to stand for 30 minutes.
Then, the protective film-forming composite sheet was irradiated with ultraviolet light from the support sheet (10) -1 side under conditions of illuminance 195mW/cm 2 and light amount 170mJ/cm 2 using an ultraviolet irradiation device (Lintec Corporation, "RAD2000 m/8"), whereby the protective film-forming film (13) -1 was cured to prepare a protective film.
Then, the silicon wafer was sliced together with the protective film using a dicing blade to obtain 5mm×5mm silicon chips.
Then, 20 silicon chips with protective films were picked up using a die bonder (die bonder) (manufactured by Canon MACHINERY INC, "BESTEM-D02"). At this time, whether or not there was a crack or a defect in the silicon chip was visually confirmed, and the case where there was no crack or defect at all was judged as "a", and the case where there was only a slight crack or defect was judged as "B", so that the pickup suitability was evaluated. The results are shown in Table 2. The column "inhibition of chip cracking and loss" in table 2 indicates the corresponding results.
(Suppression of scattering of silicon chip during dicing)
The composite sheet for forming a protective film obtained above was attached to a #2000 polished surface of a 6-inch silicon wafer (thickness 100 μm) via a film (13) -1 for forming a protective film, and the sheet was further fixed to an annular frame and allowed to stand for 30 minutes.
Then, the silicon wafer was sliced with the protective film forming film (13) -1 using a dicing blade to obtain silicon chips of 5mm×5 mm. At this time, whether or not the silicon chips were scattered from the support sheet was visually confirmed, the number of the scattered silicon chips was 0 was "a", 1 to 5 was "B", and 6 or more was "C", and dicing suitability was evaluated. The results are shown in Table 2. The column of "suppression of chip scattering" in table 2 indicates the corresponding result.
Production and evaluation of composite sheet for Forming protective film
Example 2
The surface of the same substrate (polypropylene-based film, young's modulus 400MPa, thickness 80 μm) as that used in the production of the support sheet (10) -1 was subjected to corona discharge treatment. As shown in table 2, a composite sheet for forming a protective film was produced and evaluated in the same manner as in example 1, except that the support sheet (10) -2 composed only of the substrate subjected to the surface treatment was used instead of the support sheet (10) -1. The results are shown in Table 2. In this example, a protective film forming film (13) -1 was provided on the corona discharge treated surface of the base material corresponding to the support sheet (10) -2.
Example 3
Production of composite sheet for Forming protective film
(Preparation of adhesive composition (I-4))
A non-energy ray-curable adhesive composition (I-4) was prepared which contained an acrylic polymer (100 parts by mass, solid content) and a trifunctional xylylene diisocyanate-based crosslinking agent (manufactured by Sanjingwuta chemical Co., ltd. "TAKENATE D N") (0.5 parts by mass, solid content) and further contained methyl ethyl ketone as a solvent, and the solid content concentration was 30% by mass. The acrylic polymer was obtained by copolymerizing BA (95 parts by mass) and HEA (5 parts by mass) and had a weight average molecular weight of 800000.
(Production of supporting sheet)
The support sheet (10) -3 was produced by forming a non-energy ray-curable adhesive layer having a thickness of 10 μm on the substrate in the same manner as in example 1, except that the adhesive composition (I-4) obtained above was used.
(Production of composite sheet for Forming protective film)
A composite sheet for forming a protective film was produced in the same manner as in example 1, except that the support sheet (10) -3 obtained above was used instead of the support sheet (10) -1. The composition of the obtained composite sheet for forming a protective film is shown in table 2.
Production and evaluation of composite sheet for Forming protective film
The composite sheet for forming a protective film obtained above was evaluated by the same method as in example 1. The results are shown in Table 2.
Example 4
Production of composite sheet for Forming protective film
(Preparation of composition for Forming protective film (IV-1))
As shown in table 1, a composition (IV-1) for forming a protective film was prepared in the same manner as in example 1, except that the content (blending amount) of the polymer (b) -1 was 2 parts by mass instead of 22 parts by mass, and the content (blending amount) of the filler (d) -1 was 76 parts by mass instead of 56 parts by mass.
(Production of composite sheet for Forming protective film)
An energy ray-curable protective film (13) -2 having a thickness of 25 μm was produced in the same manner as in example 1, except that the protective film-forming composition (IV-1) obtained above was used.
A composite sheet for forming a protective film was produced in the same manner as in example 1, except that the protective film forming film (13) -2 was used instead of the protective film forming film (13) -1. The composition of the obtained composite sheet for forming a protective film is shown in table 2.
Production and evaluation of composite sheet for Forming protective film
The composite sheet for forming a protective film obtained above was evaluated by the same method as in example 1. The results are shown in Table 2.
Comparative example 1
Production of composite sheet for Forming protective film
(Preparation of adhesive composition)
An energy ray-curable adhesive composition having a weight average molecular weight of 1100000, which was obtained by reacting 2EHA (80 parts by mass) and HEA (20 parts by mass) with a photopolymerization initiator (2-hydroxy-1- {4- [4- (2-hydroxy-2-methylpropanoyl) -benzyl ] phenyl } -2-methylpropan-1-one, BASF "Irgacure (registered trademark) 127" (3.0 parts by mass, solid content), and further containing methyl ethyl ketone as a solvent, was prepared, wherein the solid content concentration was 30% by mass, and the adhesive composition was an energy ray-curable adhesive composition comprising an acrylic polymer (100 parts by mass, solid content), a trifunctional xylylene diisocyanate (TAKENATE D parts by mass, and a pre-copolymer obtained by copolymerizing 2EHA (80 parts by mass) and HEA (20 parts by mass), and 2-methacryloxyethyl isocyanate (21.4 parts by mass, wherein the isocyanate group was 80 mol% relative to 100 mol% of hydroxyl groups in HEA).
(Production of supporting sheet)
A support sheet (90) -1 having an energy ray-curable adhesive layer having a thickness of 10 μm on a substrate was produced in the same manner as in example 1, except that the energy ray-curable adhesive composition obtained above was used in place of the adhesive composition (I-4).
(Production of composite sheet for Forming protective film)
A composite sheet for forming a protective film was produced in the same manner as in example 1, except that the support sheet (90) -1 obtained above was used instead of the support sheet (10) -1. The composition of the obtained composite sheet for forming a protective film is shown in table 2.
Production and evaluation of composite sheet for Forming protective film
The composite sheet for forming a protective film obtained above was evaluated by the same method as in example 1. The results are shown in Table 2.
Comparative example 2
Production of composite sheet for Forming protective film
(Preparation of composition for Forming protective film)
The contents (solid content amount, parts by mass) of the polymer (b) -2, the epoxy resin (h 1) -1, the epoxy resin (h 1) -2, the epoxy resin (h 1) -3, the thermosetting agent (h 2) -1, the curing accelerator (i) -1, the filler (d) -2, the coupling agent (e) -2, and the colorant (g) -2 were dissolved or dispersed in methyl ethyl ketone so as to be the values shown in table 1, and stirred at 23 ℃, thereby preparing a composition for forming a protective film having a solid content concentration of 50 mass%. The epoxy resin (h 1) -1, the epoxy resin (h 1) -2, the epoxy resin (h 1) -3, and the thermosetting agent (h 2) -1 are thermosetting components (h), and the resulting composition is a thermosetting composition for forming a protective film.
(Production of composite sheet for Forming protective film)
A thermosetting protective film-forming film (93) -1 having a thickness of 25 μm was produced in the same manner as in example 1, except that the thermosetting protective film-forming composition obtained above was used.
A composite sheet for forming a protective film was produced in the same manner as in example 1, except that the protective film forming film (93) -1 was used instead of the protective film forming film (13) -1. The composition of the obtained composite sheet for forming a protective film is shown in table 2.
Production and evaluation of composite sheet for Forming protective film
The composite sheet for forming a protective film obtained above was evaluated by the same method as in example 1. The results are shown in Table 2.
Comparative example 3
Production of composite sheet for Forming protective film
(Preparation of adhesive composition)
A non-energy ray-curable adhesive composition was prepared which contained an acrylic polymer (100 parts by mass, solid content) and a trifunctional xylylene diisocyanate-based crosslinking agent (manufactured by Sanjingwuta chemical Co., ltd. "TAKENATE D N") (0.5 parts by mass, solid content) and further contained methyl ethyl ketone as a solvent, the solid content concentration of which was 30% by mass. The acrylic polymer was an acrylic polymer having a weight average molecular weight of 600000, which was obtained by copolymerizing BA (79 parts by mass), MA (16 parts by mass), and HEA (5 parts by mass).
(Production of supporting sheet)
A support sheet (90) -2 having a non-energy ray-curable adhesive layer having a thickness of 10 μm on a substrate was produced in the same manner as in example 1, except that the acrylic copolymer obtained above was used.
(Production of composite sheet for Forming protective film)
A composite sheet for forming a protective film was produced in the same manner as in example 1, except that the support sheet (90) -2 obtained above was used instead of the support sheet (10) -1. The composition of the obtained composite sheet for forming a protective film is shown in table 2.
Production and evaluation of composite sheet for Forming protective film
The composite sheet for forming a protective film obtained above was evaluated by the same method as in example 1. The results are shown in Table 2.
TABLE 1
TABLE 2
From the above results, it was found that when the composite sheet for forming a protective film of examples 1 to 4 was used, the adhesion between the protective film and the supporting sheet was in the range of 55 to 1400mN/25mm, cracking and missing of the silicon chip at the time of pickup was suppressed, and other defects were not found, and the pickup suitability was excellent. When the composite sheet for forming a protective film of examples 1 to 3 was used, the adhesion between the film for forming a protective film and the support sheet was in the range of 250mN/25mm or more, scattering of silicon chips during dicing was significantly suppressed, and dicing suitability was also significantly excellent. When the composite sheet for forming a protective film of example 4 was used, scattering of silicon chips was observed in a very small portion, but it was not practically problematic.
In contrast, when the composite sheet for forming a protective film of comparative examples 1 to 3 was used, the adhesion between the protective film and the supporting sheet was in the range of 1600mN/25mm or more, which was large, cracking and missing of the silicon chip at the time of pickup could not be suppressed, and the pickup suitability was poor. Speculation: when the composite sheet for forming a protective film of comparative example 1 is used, the adhesive layer in direct contact with the film for forming a protective film is also energy ray-curable, and therefore the adhesive layer is cured at the same time as curing the film for forming a protective film, resulting in an increase in the adhesive force. On the other hand, supposedly: when the composite sheet for forming a protective film of comparative example 2 is used, the protective film forming film is thermosetting, and the adhesion between the protective film and the support sheet is not an appropriate value. And, presume that: when the composite sheet for forming a protective film of comparative example 3 was used, the sheet was provided with the same film for forming a protective film as the composite sheets for forming a protective film of examples 1 to 3, but the adhesive layer in the support sheet was strongly adhesive, and the adhesion between the protective film and the support sheet was not a suitable value.
Industrial applicability
The invention can be used for manufacturing semiconductor devices.

Claims (4)

1. A composite sheet for forming a protective film, comprising a support sheet, and an energy ray-curable protective film formed on the support sheet,
The protective film forming film is bonded to the support sheet to produce a composite sheet for forming a protective film, the composite sheet for forming a protective film is cut into a size of 25mm×140mm to produce a test piece before curing, when a tensile test is performed on the test piece before curing under conditions of a peeling angle of 180 DEG, a measurement temperature of 23 ℃ and a tensile speed of 300 mm/min to peel the support sheet from the film for forming a protective film, the adhesive force between the film for forming a protective film and the support sheet is 250mN/25mm or more,
The protective film forming film is laminated on the support sheet to produce a composite sheet for forming a protective film, the composite sheet for forming a protective film is cut into a size of 25mm×140mm to produce a test piece before curing, the test piece before curing is irradiated with ultraviolet rays under conditions of illuminance of 195mW/cm 2 and light quantity of 170mJ/cm 2, thereby curing the protective film forming film to produce a test piece after curing, when a tensile test is performed on the test piece after curing under conditions of a peeling angle of 180 DEG, a measurement temperature of 23 ℃ and a tensile speed of 300 mm/min to peel the support sheet from the protective film, the adhesive force between the protective film and the support sheet is 50 to 1500mN/25mm,
The protective film-forming film comprises: a polymer (a 1) having an energy ray-curable group and having a weight average molecular weight of 80000 ~ 2000000 or a compound (a 2) having an energy ray-curable group and having a molecular weight of 100 to 80000, the polymer (a 1) not being crosslinked,
When the protective film-forming film contains the compound (a 2), the protective film-forming film further contains a polymer (b) having no energy ray-curable group, the polymer (b) being not crosslinked,
The supporting sheet is formed by directly contacting and laminating an adhesive layer with a base material or is formed by laminating an adhesive layer on a base material through an intermediate layer,
The adhesive layer is in direct contact with the protective film forming film,
The adhesive layer is non-energy ray curable,
The adhesive layer is formed using an adhesive composition obtained by blending a non-energy ray-curable adhesive resin (I-1 a) with a crosslinking agent,
The adhesive resin (I-1 a) is an acrylic polymer having a structural unit derived from an alkyl (meth) acrylate and a structural unit derived from a functional group-containing monomer,
The functional group-containing monomer is 1 or more than 2 selected from the group consisting of hydroxyl-containing monomers, carboxyl-containing monomers, amino-containing monomers and epoxy-containing monomers,
In the adhesive layer, the content of the adhesive resin (I-1 a) is 15 to 90 mass%.
2. The protective film-forming composite sheet according to claim 1, wherein,
The protective film-forming film comprises: a compound (a 2) having an energy ray-curable group and a molecular weight of 100 to 80000, and a polymer (b) having no energy ray-curable group, wherein the polymer (b) is not crosslinked,
The polymer (b) is an acrylic polymer (b-1), the acrylic monomer constituting the acrylic polymer (b-1) is 1 or more than 2 kinds selected from the group consisting of alkyl (meth) acrylate, (meth) acrylate having a cyclic skeleton, glycidyl group-containing (meth) acrylate, hydroxyl group-containing (meth) acrylate and substituted amino group-containing (meth) acrylate,
In the protective film-forming film, the content of the polymer (b) is 6 to 130 parts by mass per 100 parts by mass of the content of the compound (a 2).
3. The protective film-forming composite sheet according to claim 1, wherein an adhesive force between the protective film and the supporting sheet is 690 to 1500mN/25mm.
4. The protective film-forming composite sheet according to any one of claims 1 to 3, further comprising a pressure-sensitive adhesive layer for jigs on the protective film-forming film or the support sheet.
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