Film for forming protective film, composite sheet for forming protective film, and method for manufacturing workpiece with protective film

Abstract

To provide a composite sheet for protection film formation, which has a support sheet and a film for protection film formation, and which makes it possible to print film for protection film formation or protection film by irradiating the film for protection film formation or protection film with laser light of a wavelength shorter than conventional ones through the support sheet from outside the composite sheet for protection film formation on a support sheet side.SOLUTION: A composite sheet 101 for protection film formation comprises: a support sheet 10; and a film 13 for protection film formation, which is provided on one face 10a of the support sheet. The support sheet has a transmittance of 20% or more to light of 355 nm in wavelength, and the film for protection film formation has a transmittance of 60% or less to light of 355 nm in wavelength.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a film for forming a protective film, a composite sheet for forming a protective film, and a method for manufacturing a workpiece with a protective film. [Background technology]

[0002] In the manufacturing process of a semiconductor device, a workpiece that needs to be processed to obtain a target product may be protected with a protective film. For example, in the manufacture of semiconductor devices using a mounting method known as the face-down method, a semiconductor wafer having electrodes such as bumps on its circuit-forming surface is used as a workpiece, and in order to prevent cracks from occurring in the semiconductor wafer or its divided semiconductor chips, the back surface of the semiconductor wafer or semiconductor chip opposite the circuit-forming surface may be protected with a protective film. Also, in the manufacturing process of a semiconductor device, a semiconductor device panel (described later) is used as a workpiece, and in order to prevent warping and cracks from occurring in this panel, some portion of the panel may be protected with a protective film.

[0003] To form such a protective film, for example, a composite sheet for forming a protective film is used, which is configured to include a support sheet, a film for forming a protective film on one side of the support sheet, and the film for forming the protective film. The film for forming a protective film may function as a protective film upon curing, or may function as a protective film in an uncured state. The support sheet can be used to fix the film for forming a protective film or a workpiece provided with a protective film. For example, when a semiconductor wafer is used as the workpiece, the support sheet can be used as a dicing sheet required when dividing the semiconductor wafer into semiconductor chips. Examples of support sheets include those comprising a substrate and an adhesive layer provided on one side of the substrate; and those consisting of a substrate. When the support sheet comprises an adhesive layer, the adhesive layer is disposed between the substrate and the film for forming a protective film in the composite sheet for forming a protective film.

[0004] When using the above-mentioned composite sheet for forming a protective film, first, the film for forming a protective film in the composite sheet for forming a protective film is attached to the desired location on the workpiece. Next, the workpiece provided with such a composite sheet for forming a protective film is processed as necessary to obtain a workpiece. Then, at any stage before obtaining the desired semiconductor device, the surface of the film for forming a protective film or protective film opposite the surface attached to the workpiece or workpiece (i.e., the surface on the support sheet side in the composite sheet for forming a protective film) may be printed (laser printed) by irradiating it with laser light. This printing is used, for example, to identify the workpiece or workpiece provided with the protective film. The printing applied to the film for forming a protective film remains in the same state even after the protective film is formed by curing the film, so laser printing may be performed at either the film for forming a protective film or the protective film.

[0005] For example, when laser printing is performed on a laminate having a structure in which a support sheet, a film or protective film for forming a protective film, and a workpiece or workpiece are stacked in this order in the thickness direction, laser light is irradiated onto the film or protective film for forming a protective film from outside the support sheet side of the laminate, through the support sheet, or laser light is irradiated onto the film or protective film for forming a protective film from outside the workpiece or workpiece side of the laminate, through the workpiece or workpiece.

[0006] Among these, when irradiating a laser beam through a support sheet, the following problem may occur. That is, the support sheet needs to transmit the laser beam at a certain level or more, and the support sheet usually contains a component capable of absorbing the light. In particular, such components are frequently used in curable pressure-sensitive adhesive layers. Therefore, it is necessary to adjust the composition of the support sheet so as not to excessively hinder the transmission of the laser beam.

[0007] On the other hand, the wavelength of the laser light irradiated at this time may be any wavelength that allows printing. Until now, for example, laser light with a wavelength of 532 nm or 1064 nm, for which a method for generating the laser light has been established, has been widely used. However, it has been found that printing accuracy is improved when laser light with a shorter wavelength is used for printing, and it would be very useful if laser light with a shorter wavelength than conventional laser light could be used.

[0008] As an example of a support sheet having a certain level or higher transmittance for shorter wavelength light, a dicing tape having a light transmittance of 30% or higher at a wavelength of 400 nm has been disclosed (see Patent Document 1). This dicing tape corresponds to the support sheet. This dicing tape is used in combination with an adhesive film having a light transmittance of 20% or lower at a wavelength of 400 nm. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-74129 Summary of the Invention [Problem to be solved by the invention]

[0010] However, the dicing tape disclosed in Patent Document 1 has unknown light transmittance for wavelengths shorter than 400 nm. Furthermore, this dicing tape is used in combination with an adhesive film, which is intended to adhere a semiconductor chip (corresponding to the workpiece) to a desired location, not to form a protective film on the backside of the semiconductor chip. The light transmittance of the dicing tape and adhesive film at a wavelength of 400 nm is specified so that the presence or absence of peeling between the adhesive film and the dicing tape can be observed from the dicing tape side. Thus, the dicing tape and adhesive film integrated as disclosed in Patent Document 1 is not a composite sheet for forming a protective film. The light transmittance characteristics required for the dicing tape and adhesive film will naturally differ depending on their intended use. In contrast, there are no known composite sheets for forming protective films that can be printed with laser light having a shorter wavelength than conventional ones.

[0011] The present invention aims to provide a composite sheet for forming a protective film, which is configured with a support sheet and a film for forming a protective film, and which can form a protective film from the film for forming a protective film to protect any part of a workpiece or a workpiece processed product, and which can print on the film for forming a protective film or the protective film by irradiating the film for forming a protective film or the protective film with laser light of a shorter wavelength than conventional laser light from outside the support sheet side of the composite sheet for forming a protective film, through the support sheet. Another object of the present invention is to provide a film for forming a protective film that can constitute the composite sheet for forming a protective film. [Means for solving the problem]

[0012] The present invention provides a film for forming a protective film, which has a transmittance of 60% or less for light having a wavelength of 355 nm. The present invention provides a composite sheet for forming a protective film, comprising a support sheet and a film for forming a protective film provided on one side of the support sheet, wherein the transmittance of the support sheet for light having a wavelength of 355 nm is 20% or more, and the film for forming a protective film is the film for forming a protective film of the present invention.

[0013] In the composite sheet for forming a protective film of the present invention, the transmittance of the support sheet to light having a wavelength of 355 nm is preferably equal to or greater than the transmittance of the film for forming a protective film to light having a wavelength of 355 nm. In the composite sheet for forming a protective film of the present invention, it is preferable that the composite sheet for forming a protective film is to be attached to the back surface of a semiconductor wafer, and that the semiconductor wafer does not have a groove that runs through between the back surface and the circuit formation surface opposite the back surface. The composite sheet for forming a protective film of the present invention is for forming a protective film at any location on a workpiece obtained by processing the workpiece, and the film for forming a protective film is for use by being attached to any location on the workpiece. If the film for forming a protective film is curable, the cured product of the film for forming a protective film is the protective film. If the film for forming a protective film is non-curable, the film for forming a protective film after being attached to any location on the workpiece is the protective film. It is preferable that the film for forming a protective film in the composite sheet for forming a protective film is attached to any location on the workpiece, and then the film for forming a protective film or the protective film in the composite sheet for forming a protective film is used to print on the film for forming a protective film or the protective film by irradiating laser light from outside the support sheet side of the composite sheet for forming a protective film, through the support sheet.

[0014] The present invention is a method for manufacturing a workpiece with a protective film, the workpiece with a protective film comprising a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, the protective film being formed from a film for forming a protective film in the composite sheet for forming a protective film of the present invention, and when the film for forming a protective film is curable, a cured product of the film for forming a protective film is the protective film, and when the film for forming a protective film is non-curable, the film for forming a protective film after being attached to any location on the workpiece is the protective film, and the method for manufacturing the workpiece with a protective film comprises attaching the film for forming a protective film in the composite sheet for forming a protective film to a desired location on the workpiece, a printing step, after the attaching step, of printing on the film for protective film formation or the protective film in the composite sheet for protective film formation in the first laminate by irradiating laser light having a wavelength of 355 nm from outside the support sheet side of the composite sheet for protective film formation through the support sheet, and a processing step, after the printing step, of processing the work to produce a workpiece; and if the film for protective film formation is curable, the method further includes a curing step, after the attaching step, of curing the film for protective film formation to form a protective film. The present invention is a method for manufacturing a workpiece with a protective film, the workpiece with a protective film comprising a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, the protective film being formed from the protective film forming film of the present invention, and when the protective film forming film is curable, a cured product of the protective film forming film is the protective film, and when the protective film forming film is non-curable, the protective film is the protective film after being attached to any location on the workpiece, and the method for manufacturing the workpiece with a protective film comprises attaching the protective film forming film to a desired location on the workpiece to form the protective film on the workpiece. The present invention provides a method for manufacturing a workpiece with a protective film, the method comprising: an attachment step of producing a second laminate provided with a forming film or a protective film; a printing step of printing on the protective film forming film or the protective film in the second laminate after the attachment step by directly irradiating the protective film forming film or the protective film with laser light having a wavelength of 355 nm from the outside of the protective film forming film or the protective film opposite the work side; and a processing step of processing the workpiece to produce a workpiece after the printing step, and if the protective film forming film is curable, the method further comprises a curing step of forming a protective film by curing the protective film forming film after the attachment step. [Effects of the Invention]

[0015] The present invention provides a composite sheet for forming a protective film, which is configured with a support sheet and a film for forming a protective film, and which can form a protective film from the film for forming a protective film to protect any part of a workpiece or a workpiece processed product, and which can print on the film for forming a protective film or the protective film by irradiating the film for forming a protective film or the protective film with laser light having a shorter wavelength than conventional laser light from outside the support sheet side of the composite sheet for forming a protective film, through the support sheet. The present invention also provides a film for forming a protective film that can constitute the composite sheet for forming a protective film. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view schematically illustrating an example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 2] FIG. 3 is a cross-sectional view schematically showing another example of a composite sheet for forming a protective film according to one embodiment of the present invention. [Figure 3] FIG. 10 is a cross-sectional view schematically showing yet another example of a composite sheet for forming a protective film according to one embodiment of the present invention. [Figure 4] FIG. 10 is a cross-sectional view schematically showing yet another example of a composite sheet for forming a protective film according to one embodiment of the present invention. [Figure 5] 1A to 1C are cross-sectional views for schematically explaining an example of a method for manufacturing a semiconductor chip with a protective film when a composite sheet for forming a protective film according to one embodiment of the present invention is used. DETAILED DESCRIPTION OF THE INVENTION

[0017] ◇Protective film forming film The film for forming a protective film according to one embodiment of the present invention has a transmittance of 60% or less for light having a wavelength of 355 nm (sometimes abbreviated as "light (355 nm)" in this specification). The film for forming a protective film of this embodiment can be laminated with a support sheet, for example, as described below, to form a composite sheet for forming a protective film.

[0018] The film for forming a protective film of this embodiment forms a protective film for protecting any part of a processed workpiece, and can also form a protective film for protecting any part of a workpiece before processing. Examples of the workpiece include semiconductor wafers, semiconductor device panels, etc. A semiconductor device panel is handled in the manufacturing process of a semiconductor device, and a specific example thereof is a semiconductor device in which one or more electronic components are sealed with a sealing resin, and a plurality of such semiconductor devices are arranged in a plane within a circular, rectangular, or other shaped area. In this specification, a processed workpiece is referred to as a “workpiece artifact.” For example, if the workpiece is a semiconductor wafer, an example of the workpiece artifact is a semiconductor chip. For example, when the workpiece is a semiconductor wafer, the support sheet can be used to fix a film for forming a protective film or a semiconductor wafer having a protective film on the back surface.

[0019] For example, when the workpiece is a semiconductor wafer, by using the film for forming a protective film of this embodiment, a protective film can be formed on the surface of the semiconductor wafer or semiconductor chip opposite to the circuit-forming surface (either of these may be referred to as the "back surface" in this specification.) In this specification, a workpiece having such a protective film may be referred to as a "workpiece having a protective film," and a semiconductor chip having a protective film on its back surface may be referred to as a "semiconductor chip having a protective film." The protective film forming film is soft and can be easily attached to an object such as a workpiece or a processed workpiece.

[0020] The protective film forming film of this embodiment may function as a protective film by being cured, or may function as a protective film in an uncured state. The protective film forming film that functions as a protective film in an uncured state can be considered to have formed a protective film, for example, when it is attached to a desired location on a workpiece.

[0021] The film for forming a protective film of this embodiment has low light (355 nm) transmittance and high light (355 nm) absorbency. Therefore, by irradiating the film for forming a protective film or the protective film with laser light having a shorter wavelength than conventional ones, such as a wavelength of 355 nm, the film for forming a protective film or the protective film can be printed well. Furthermore, the film for forming a protective film of this embodiment can be printed with higher precision than conventional films by irradiating it with a laser beam having such a short wavelength. The film for forming a protective film and its cured product (for example, a protective film) exhibit roughly the same transmittance and absorbance for light of the same wavelength.

[0022] Furthermore, when the protective film-forming film of this embodiment is combined with a support sheet having a certain level or higher of light (355 nm) transmittance to form a composite sheet for protective film formation, the protective film-forming film or protective film in the composite sheet for protective film formation can be printed well by irradiating the protective film-forming film or protective film in the composite sheet for protective film formation with laser light having a shorter wavelength than conventional ones, such as 355 nm, from outside the support sheet side of the composite sheet for protective film formation through the support sheet. This printing can then be clearly seen from outside the support sheet side of the composite sheet for protective film formation through the support sheet.

[0023] In this specification, unless otherwise specified, "printing" means printing on a film for forming a protective film or a protective film in a composite sheet for forming a protective film by irradiating the film or protective film with laser light from outside the support sheet side of the composite sheet for forming a protective film, through the support sheet, as described above.

[0024] In this specification, unless otherwise specified, "visual inspection of the film for forming a protective film or the printing on the protective film" means visual inspection of the film for forming a protective film or the printing on the protective film through the support sheet from outside the support sheet side of the composite sheet for forming a protective film, as described above.

[0025] Conventionally, laser light having a wavelength of 532 nm or 1064 nm has been widely used for printing on a film for forming a protective film or a protective film. In contrast, printing accuracy can be improved by printing with laser light having a shorter wavelength than conventional laser light, such as a wavelength of 355 nm.

[0026] In this specification, "ability to print well" means that the printability is good, i.e., the desired characters can be printed in an accurately identifiable manner. Also, "ability to visually recognize the print well" means that the print visibility is good, i.e., the print can be recognized visually without error.

[0027] The transmittance of the film for forming a protective film to light (355 nm) may be, for example, any one of 55% or less, 45% or less, 35% or less, and 25% or less. When the transmittance of the film for forming a protective film is equal to or less than the upper limit, the printability of the film for forming a protective film or the protective film and the print visibility thereof are further improved.

[0028] The lower limit of the transmittance of light (355 nm) of the film for forming a protective film is not particularly limited and may be, for example, 0%. For example, a film for forming a protective film having the transmittance of 1% or more is easier to manufacture, and the transmittance may be 10% or more.

[0029] The transmittance of light (355 nm) of the film for forming a protective film can be appropriately adjusted within a range set by arbitrarily combining the above-mentioned lower limit and any of the upper limits. For example, in one embodiment, the transmittance of the film for forming a protective film may be any of 1 to 60%, 1 to 55%, 1 to 45%, 1 to 35%, and 1 to 25%, or any of 10 to 60%, 10 to 55%, 10 to 45%, 10 to 35%, and 10 to 25%. However, these are just examples of the transmittance of the film for forming a protective film.

[0030] As described above, the protective film-forming film may be curable or non-curable. The curable protective film-forming film may be either thermosetting or energy ray-curable, or may have both thermosetting and energy ray-curable properties.

[0031] As used herein, "energy rays" refers to electromagnetic waves or charged particle beams that have an energy quantum, and examples thereof include ultraviolet rays, radioactive rays, and electron beams. Ultraviolet rays can be irradiated using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet light source. Electron beams can be irradiated using those generated by an electron beam accelerator or the like. In this specification, "energy ray curable" means a property of being cured by irradiation with energy rays, and "non-energy ray curable" means a property of not being cured even when irradiated with energy rays. In this specification, the term "non-curable" means a property that does not cure by any means such as heating or irradiation with energy rays.

[0032] When a protective film is formed by thermally curing a protective film-forming film, unlike when the film is cured by irradiation with energy rays, the protective film-forming film is sufficiently cured by heating even if the film is thick, so that a protective film with high protective performance can be formed. Furthermore, by using a conventional heating means such as a heating oven, a large number of protective film-forming films can be heated and thermally cured all at once. When a protective film is formed by curing a protective film-forming film by irradiation with energy rays, the composite sheet for forming a protective film does not need to be heat-resistant, unlike when the film is thermally cured, and a wide range of composite sheets for forming a protective film can be constructed. Furthermore, the film can be cured in a short time by irradiation with energy rays. When the protective film-forming film is used as a protective film without being cured, the curing step can be omitted, and therefore a workpiece with a protective film can be manufactured through a simplified process.

[0033] Regardless of whether the film for forming a protective film is curable or non-curable, and if it is curable, regardless of whether it is thermosetting or energy ray-curable, the film for forming a protective film may consist of one layer (single layer) or may consist of two or more layers. When the film for forming a protective film consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0034] In this specification, not only in the case of a film for forming a protective film, "multiple layers may be the same or different from one another" means "all layers may be the same, all layers may be different, or only some layers may be the same," and further, "multiple layers are different from one another" means "at least one of the constituent materials and thicknesses of each layer is different from one another."

[0035] Regardless of whether the protective film-forming film is curable or non-curable, and if curable, regardless of whether it is thermosetting or energy ray-curable, the thickness of the protective film-forming film is preferably 1 to 100 μm, more preferably 3 to 80 μm, and particularly preferably 5 to 60 μm, and may be, for example, either 5 to 40 μm or 5 to 20 μm. When the thickness of the protective film-forming film is equal to or greater than the lower limit, a protective film with higher protective ability can be formed. When the thickness of the protective film-forming film is equal to or less than the upper limit, excessive thickness can be avoided. Here, "thickness of the film for forming a protective film" means the thickness of the entire film for forming a protective film, for example, the thickness of a film for forming a protective film consisting of multiple layers means the total thickness of all layers that make up the film for forming a protective film.

[0036] <<Composition for forming protective film>> The film for forming a protective film can be formed using a composition for forming a protective film containing its constituent materials. For example, the film for forming a protective film can be formed by applying the composition for forming a protective film to the surface to be formed and drying it as necessary. The ratio of the contents of the components that do not vaporize at room temperature in the composition for forming a protective film is usually the same as the ratio of the contents of the components in the film for forming a protective film. In this specification, "room temperature" means a temperature that is not particularly cooled or heated, i.e., an ordinary temperature, and examples thereof include a temperature of 15 to 25°C.

[0037] A thermosetting protective film-forming film can be formed using a thermosetting protective film-forming composition, an energy ray-curable protective film-forming film can be formed using an energy ray-curable protective film-forming composition, and a non-curable protective film-forming film can be formed using a non-curable protective film-forming composition. In this specification, when a protective film-forming film has both thermosetting and energy ray-curable properties, if the contribution of the thermosetting of the protective film-forming film to the formation of the protective film is greater than the contribution of the energy ray-curing, the protective film-forming film is treated as a thermosetting film. Conversely, if the contribution of the energy ray-curing of the protective film-forming film to the formation of the protective film is greater than the contribution of the thermosetting, the protective film-forming film is treated as an energy ray-curable film.

[0038] The protective film-forming composition may be applied by a known method, such as a method using various coaters such as an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, Mayer bar coater, or kiss coater.

[0039] Regardless of whether the protective film-forming film is curable or non-curable, and if it is curable, regardless of whether it is heat-curable or energy ray-curable, the drying conditions for the protective film-forming composition are not particularly limited. However, when the protective film-forming composition contains a solvent as described below, it is preferably dried by heating. A protective film-forming composition containing a solvent is preferably dried by heating, for example, at 70 to 130°C for 10 seconds to 5 minutes. However, a thermosetting protective film-forming composition is preferably dried by heating so as not to thermally cure the composition itself or the thermosetting protective film-forming film formed from this composition.

[0040] The thermosetting protective film-forming film, the energy ray-curable protective film-forming film, and the non-curable protective film-forming film will be described below in order.

[0041] ◎Thermosetting protective film The curing conditions when a thermosetting protective film forming film is attached to the desired location on the workpiece and thermally cured to form a protective film are not particularly limited, as long as the protective film is cured to a degree that allows it to fully perform its function, and can be selected appropriately depending on the type of thermosetting protective film forming film. For example, the heating temperature during thermal curing of the thermosetting film for forming a protective film is preferably 100 to 200° C., more preferably 110 to 180° C., and particularly preferably 120 to 170° C. The heating time during thermal curing is preferably 0.5 to 5 hours, more preferably 0.5 to 3 hours, and particularly preferably 1 to 2 hours.

[0042] A preferred example of a thermosetting protective film-forming film is one containing a polymer component (A) and a thermosetting component (B). The polymer component (A) is a component that can be considered to be formed by a polymerization reaction of a polymerizable compound. The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction when heat is used as a reaction trigger. In this specification, polymerization reaction also includes polycondensation reaction.

[0043] <Thermosetting protective film forming composition (III-1)> A preferred example of a composition for forming a thermosetting protective film is a composition for forming a thermosetting protective film (III-1) (sometimes abbreviated herein as "composition (III-1)") containing the polymer component (A) and the thermosetting component (B).

[0044] [Polymer component (A)] The polymer component (A) is a component for imparting film-forming properties, flexibility, etc. to the thermosetting film for forming a protective film. The polymer component (A) contained in the composition (III-1) and the thermosetting protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0045] Examples of the polymer component (A) include acrylic resins, polyesters, urethane resins, acrylic urethane resins, silicone resins, rubber resins, phenoxy resins, and polyimides, with acrylic resins being preferred.

[0046] Examples of the acrylic resin in the polymer component (A) include known acrylic polymers. The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000. When the weight-average molecular weight of the acrylic resin is equal to or greater than the lower limit, the shape stability (stability over time during storage) of the thermosetting protective film-forming film is improved. Furthermore, when the weight-average molecular weight of the acrylic resin is equal to or less than the upper limit, the thermosetting protective film-forming film can more easily conform to the uneven surface of the adherend, further suppressing the occurrence of voids and the like between the adherend and the thermosetting protective film-forming film. In this specification, unless otherwise specified, the "weight average molecular weight" is a polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0047] The glass transition temperature (Tg) of the acrylic resin is preferably −60 to 70° C., more preferably −30 to 50° C. When the Tg of the acrylic resin is equal to or greater than the lower limit, for example, the adhesive strength between the cured product of the protective film-forming film and the support sheet is suppressed, and the peelability of the support sheet is appropriately improved. Furthermore, when the Tg of the acrylic resin is equal to or less than the upper limit, the adhesive strength between the thermosetting protective film-forming film and its cured product and the adherend is improved.

[0048] When an acrylic resin has m types of structural units (m is an integer of 2 or more) and the m types of monomers from which these structural units are derived are each assigned a unique number from 1 to m, and named "monomer m," the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox formula shown below.

[0049]

number

[0050]

number

[0051] The Tg k The values ​​listed in the Polymer Data Handbook or the Adhesive Handbook can be used. For example, the Tg of methyl acrylate homopolymer is k is 10°C, and the Tg of the homopolymer of methyl methacrylate k is 105°C, and the Tg of the homopolymer of 2-hydroxyethyl acrylate k is -15℃.

[0052] Examples of acrylic resins include polymers of one or more (meth)acrylic acid esters; copolymers of two or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide.

[0053] Examples of the (meth)acrylic acid ester constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and p) (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure and has 1 to 18 carbon atoms, such as isononyl acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate); (meth)acrylic acid cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate; (Meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester; (Meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyloxyethyl ester; (Meth)acrylic acid imide; glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; hydroxyl group-containing (meth)acrylic acid esters 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; Examples include substituted amino group-containing (meth)acrylic acid esters such as N-methylaminoethyl (meth)acrylate. Here, the term "substituted amino group" refers to a group in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom.

[0054] In this specification, the term "(meth)acrylic acid" encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid. For example, the term "(meth)acryloyl group" encompasses both "acryloyl group" and "methacryloyl group," and the term "(meth)acrylate" encompasses both "acrylate" and "methacrylate."

[0055] The acrylic resin may be obtained by copolymerizing, in addition to the (meth)acrylic acid ester, one or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like.

[0056] The acrylic resin may be made up of one kind of monomer or two or more kinds of monomers, and when two or more kinds of monomers are used, the combination and ratio thereof can be selected arbitrarily.

[0057] The acrylic resin may have a functional group capable of bonding to other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group. The functional group of the acrylic resin may bond to other compounds via a crosslinking agent (F) described below, or may bond directly to other compounds without the crosslinking agent (F). Bonding of the acrylic resin to other compounds via the functional group tends to improve the reliability of a package obtained using the composite sheet for forming a protective film.

[0058] In the present invention, a thermoplastic resin other than an acrylic resin (hereinafter sometimes simply referred to as a "thermoplastic resin") may be used as the polymer component (A) either alone without an acrylic resin or in combination with an acrylic resin. The use of such a thermoplastic resin may improve the peelability of the protective film from the support sheet, or may facilitate conforming of the thermosetting film for forming a protective film to the uneven surface of the adherend, thereby further suppressing the occurrence of voids between the adherend and the film for forming a thermosetting protective film.

[0059] The weight average molecular weight of the thermoplastic resin is preferably 1,000 to 100,000, and more preferably 3,000 to 80,000.

[0060] The glass transition temperature (Tg) of the thermoplastic resin is preferably from -30 to 150°C, more preferably from -20 to 120°C.

[0061] Examples of the thermoplastic resin include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

[0062] The thermoplastic resin contained in the composition (III-1) and the film for forming a thermosetting protective film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0063] In composition (III-1), the ratio of the content of polymer component (A) to the total content of all components other than the solvent (i.e., the ratio of the content of polymer component (A) in the thermosetting protective film-forming film to the total mass of the thermosetting protective film-forming film) is preferably 10 to 85 mass%, more preferably 15 to 70 mass%, and even more preferably 20 to 60 mass%, regardless of the type of polymer component (A), and may be, for example, any of 20 to 45 mass%, 20 to 35 mass%, 35 to 60 mass%, and 45 to 60 mass%.

[0064] The polymer component (A) may also correspond to the thermosetting component (B). In the present invention, when the composition (III-1) contains components that correspond to both the polymer component (A) and the thermosetting component (B), the composition (III-1) is considered to contain the polymer component (A) and the thermosetting component (B).

[0065] [Thermosetting component (B)] The thermosetting component (B) is a component for curing the thermosetting protective film-forming film. The thermosetting component (B) contained in the composition (III-1) and the thermosetting protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0066] Examples of the thermosetting component (B) include epoxy-based thermosetting resins, polyimides, polyurethanes, unsaturated polyesters, and silicone resins, with epoxy-based thermosetting resins being preferred.

[0067] (epoxy thermosetting resin) The epoxy thermosetting resin is composed of an epoxy resin (B1) and a thermosetting agent (B2). The epoxy-based thermosetting resin contained in the composition (III-1) and the film for forming a thermosetting protective film may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0068] Epoxy resin (B1) Examples of the epoxy resin (B1) include known epoxy resins, such as bifunctional or higher functional epoxy compounds, including polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene-type epoxy resins, biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and phenylene skeleton-type epoxy resins.

[0069] The epoxy resin (B1) may be an epoxy resin having an unsaturated hydrocarbon group. Epoxy resins having an unsaturated hydrocarbon group have higher compatibility with acrylic resins than epoxy resins without an unsaturated hydrocarbon group. Therefore, the use of an epoxy resin having an unsaturated hydrocarbon group improves the reliability of the workpiece with a protective film obtained using the composite sheet for forming a protective film.

[0070] Examples of epoxy resins having unsaturated hydrocarbon groups include compounds obtained by converting some of the epoxy groups of a polyfunctional epoxy resin into groups having unsaturated hydrocarbon groups. Such compounds can be obtained, for example, by subjecting epoxy groups to an addition reaction with (meth)acrylic acid or a derivative thereof. Furthermore, examples of epoxy resins having an unsaturated hydrocarbon group include compounds in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring or the like constituting the epoxy resin. The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include an ethenyl group (vinyl group), a 2-propenyl group (allyl group), a (meth)acryloyl group, and a (meth)acrylamide group, with an acryloyl group being preferred.

[0071] The number average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoints of the curability of the thermosetting film for forming a protective film and the strength and heat resistance of the protective film, it is preferably 300 to 30,000, more preferably 300 to 10,000, and particularly preferably 300 to 3,000. The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1000 g / eq, more preferably 150 to 950 g / eq.

[0072] The epoxy resin (B1) may be used alone or in combination of two or more kinds. When two or more kinds are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0073] Heat hardener (B2) The heat curing agent (B2) functions as a curing agent for the epoxy resin (B1). The thermosetting agent (B2) may be, for example, a compound having two or more functional groups per molecule that can react with an epoxy group. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an anhydride group of an acid group. A phenolic hydroxyl group, an amino group, or an anhydride group of an acid group is preferred, and a phenolic hydroxyl group or an amino group is more preferred.

[0074] Among the heat curing agents (B2), examples of phenolic curing agents having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Among the heat curing agents (B2), examples of amine-based curing agents having an amino group include dicyandiamide.

[0075] The heat curing agent (B2) may have an unsaturated hydrocarbon group. Examples of the thermosetting agent (B2) having an unsaturated hydrocarbon group include a compound in which some of the hydroxyl groups of a phenolic resin are substituted with a group having an unsaturated hydrocarbon group, and a compound in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of a phenolic resin. The unsaturated hydrocarbon group in the heat curing agent (B2) is the same as the unsaturated hydrocarbon group in the epoxy resin having an unsaturated hydrocarbon group described above.

[0076] When a phenol-based curing agent is used as the heat curing agent (B2), the heat curing agent (B2) preferably has a high softening point or glass transition temperature, in order to improve the peelability of the protective film from the support sheet.

[0077] Of the thermosetting agents (B2), for example, the number average molecular weight of resin components such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000. Of the thermosetting agent (B2), the molecular weight of the non-resin component such as biphenol or dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

[0078] The heat curing agent (B2) may be used alone or in combination of two or more kinds. When two or more kinds are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0079] In the composition (III-1) and the thermosetting film for forming a protective film, the content of the thermosetting agent (B2) is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, per 100 parts by mass of the epoxy resin (B1). For example, it may be any of 0.5 to 25 parts by mass, 0.5 to 10 parts by mass, and 0.5 to 5 parts by mass. When the content of the thermosetting agent (B2) is equal to or greater than the lower limit, curing of the thermosetting film for forming a protective film proceeds more easily. When the content of the thermosetting agent (B2) is equal to or less than the upper limit, the moisture absorption rate of the thermosetting film for forming a protective film is reduced, and the reliability of the package obtained using the composite sheet for forming a protective film is further improved.

[0080] In the composition (III-1) and the thermosetting film for forming a protective film, the content of the thermosetting component (B) (e.g., the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is preferably 5 to 120 parts by mass, more preferably 5 to 80 parts by mass, relative to 100 parts by mass of the content of the polymer component (A). For example, it may be any of 5 to 40 parts by mass, 5 to 20 parts by mass, and 5 to 10 parts by mass, or any of 40 to 80 parts by mass, 50 to 75 parts by mass, and 60 to 75 parts by mass. When the content of the thermosetting component (B) is within this range, for example, the adhesive strength between the cured product of the film for forming a protective film and the support sheet is suppressed, improving the releasability of the support sheet.

[0081] [Curing accelerator (C)] The composition (III-1) and the thermosetting film for forming a protective film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of the composition (III-1). Preferred examples of the curing accelerator (C) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines (phosphines in which one or more hydrogen atoms are substituted with organic groups) such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

[0082] The curing accelerator (C) contained in the composition (III-1) and the thermosetting protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0083] When a curing accelerator (C) is used, the content of the curing accelerator (C) in the composition (III-1) and the thermosetting film for forming a protective film is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 7 parts by mass, per 100 parts by mass of the thermosetting component (B). When the content of the curing accelerator (C) is equal to or greater than the lower limit, the effects of using the curing accelerator (C) are more pronounced. When the content of the curing accelerator (C) is equal to or less than the upper limit, for example, the highly polar curing accelerator (C) is more effectively inhibited from migrating and segregating to the adhesive interface with the adherend under high temperature and high humidity conditions in the film for forming a thermosetting protective film. As a result, the reliability of the workpiece with a protective film obtained using the composite sheet for forming a protective film is further improved.

[0084] [Filling material (D)] The composition (III-1) and the thermosetting film for forming a protective film may contain a filler (D). When the film for forming a thermosetting protective film contains the filler (D), the thermal expansion coefficients of the film for forming a thermosetting protective film and the protective film can be easily adjusted. By optimizing this thermal expansion coefficient for the object on which the protective film is to be formed, the reliability of the workpiece with the protective film obtained using the composite sheet for forming a protective film is further improved. Furthermore, when the film for forming a thermosetting protective film contains the filler (D), the moisture absorption rate of the protective film can be reduced and the heat dissipation properties can be improved.

[0085] The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler. Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride, etc.; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; glass fibers, etc. Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

[0086] The filler (D) contained in the composition (III-1) and the thermosetting film for forming a protective film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0087] In composition (III-1), the ratio of the content of filler (D) to the total content of all components other than the solvent (i.e., the ratio of the content of filler (D) in the thermosetting film for forming a protective film to the total mass of the film for forming a thermosetting protective film) is preferably 15 to 70 mass%, more preferably 30 to 60 mass%, and may be, for example, any of 35 to 60 mass%, 40 to 60 mass%, and 45 to 60 mass%, or any of 30 to 55 mass%, 30 to 50 mass%, and 30 to 45 mass%. When the ratio is in this range, it becomes easier to adjust the thermal expansion coefficients of the thermosetting film for forming a protective film and the protective film.

[0088] [Coupling agent (E)] The composition (III-1) and the thermosetting film for forming a protective film may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesiveness and adhesion of the thermosetting film for forming a protective film to an adherend can be improved. Furthermore, by using the coupling agent (E), the water resistance of the protective film formed from the thermosetting film for forming a protective film is improved without impairing the heat resistance.

[0089] The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional group of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent. Preferred examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- Examples of such silanes include (aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazole silane.

[0090] The coupling agent (E) contained in the composition (III-1) and the thermosetting protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0091] When a coupling agent (E) is used, the content of the coupling agent (E) in the composition (III-1) and the thermosetting protective film-forming film is preferably 0.03 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and particularly preferably 0.1 to 2 parts by mass, per 100 parts by mass of the total content of the polymer component (A) and the thermosetting component (B). When the content of the coupling agent (E) is at or above the lower limit, the effects of using the coupling agent (E), such as improved dispersibility of the filler (D) in the resin and improved adhesion of the thermosetting protective film-forming film to the substrate, are more significantly achieved. Furthermore, when the content of the coupling agent (E) is at or below the upper limit, outgassing is further suppressed.

[0092] [Crosslinker (F)] When the polymer component (A) is one having a functional group such as a vinyl group, (meth)acryloyl group, amino group, hydroxyl group, carboxy group, or isocyanate group that can bond with other compounds, such as the above-mentioned acrylic resins, the composition (III-1) and the thermosetting film for forming a protective film may contain a crosslinking agent (F). The crosslinking agent (F) is a component that bonds the functional group in the polymer component (A) with other compounds to form a crosslink, and by crosslinking in this manner, the initial adhesive strength and cohesive strength of the film for forming a thermosetting protective film can be adjusted.

[0093] Examples of the crosslinking agent (F) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridinyl group).

[0094] The crosslinking agent (F) contained in the composition (III-1) and the thermosetting film for forming a protective film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0095] When a crosslinking agent (F) is used, the content of the crosslinking agent (F) in the composition (III-1) 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, per 100 parts by mass of the polymer component (A). When the content of the crosslinking agent (F) is equal to or greater than the lower limit, the effect of using the crosslinking agent (F) is more pronounced. Furthermore, when the content of the crosslinking agent (F) is equal to or less than the upper limit, excessive use of the crosslinking agent (F) is suppressed.

[0096] [Energy ray curable resin (G)] The composition (III-1) and the film for forming a thermosetting protective film may contain an energy ray-curable resin (G). By containing the energy ray-curable resin (G), the film for forming a thermosetting protective film can change its properties by irradiation with energy rays.

[0097] The energy ray curable resin (G) is obtained by polymerizing (curing) an energy ray curable compound. Examples of the energy ray-curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

[0098] Examples of the acrylate compounds include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. (meth)acrylates containing a cyclic aliphatic skeleton; (meth)acrylates containing a cyclic aliphatic skeleton such as dicyclopentanyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates; urethane (meth)acrylate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the above-mentioned polyalkylene glycol (meth)acrylates; and itaconic acid oligomers.

[0099] The weight average molecular weight of the energy ray-curable compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

[0100] The energy ray-curable compound used in the polymerization may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof can be selected arbitrarily.

[0101] The energy ray-curable resin (G) contained in the composition (III-1) and the thermosetting protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0102] When the energy ray curable resin (G) is used, the content of the energy ray curable resin (G) in the composition (III-1) relative to the total mass of the composition (III-1) is preferably 1 to 95 mass%, more preferably 5 to 90 mass%, and particularly preferably 10 to 85 mass%.

[0103] [Photopolymerization initiator (H)] When the composition (III-1) and the thermosetting protective film-forming film contain an energy ray-curable resin (G), they may contain a photopolymerization initiator (H) to efficiently promote the polymerization reaction of the energy ray-curable resin (G).

[0104] Examples of the photopolymerization initiator (H) in the composition (III-1) include the same photopolymerization initiators as those that may be contained in the above-mentioned pressure-sensitive adhesive composition.

[0105] The photopolymerization initiator (H) contained in the composition (III-1) and the thermosetting protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0106] When the photopolymerization initiator (H) is used, the content of the photopolymerization initiator (H) in the composition (III-1) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and particularly preferably 2 to 5 parts by mass, per 100 parts by mass of the energy ray-curable resin (G).

[0107] [Colorant (I)] The composition (III-1) and the thermosetting film for forming a protective film preferably contain a colorant (I). By using the colorant (I), a film for forming a protective film having a light (355 nm) transmittance of 60% or less can be more easily produced.

[0108] Examples of the colorant (I) include known colorants such as inorganic pigments, organic pigments, and organic dyes.

[0109] Examples of the organic pigments and organic dyes include aminium-based dyes, cyanine-based dyes, merocyanine-based dyes, croconium-based dyes, squarium-based dyes, azulenium-based dyes, polymethine-based dyes, naphthoquinone-based dyes, pyrylium-based dyes, phthalocyanine-based dyes, naphthalocyanine-based dyes, naphtholactam-based dyes, azo-based dyes, condensed azo-based dyes, indigo-based dyes, perinone-based dyes, perylene-based dyes, dioxazine-based dyes, quinacridone-based dyes, isoindolinone-based dyes, quinophthalone-based dyes, pyrrole-based dyes, thioindigo-based dyes, metal complex-based dyes (metal complex dyes), dithiol metal complex-based dyes, indolephenol-based dyes, triallylmethane-based dyes, anthraquinone-based dyes, dioxazine-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyranthrone-based dyes, and threne-based dyes.

[0110] Examples of the inorganic pigments include carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO (indium tin oxide)-based pigments, and ATO (antimony tin oxide)-based pigments.

[0111] The colorant (I) contained in the composition (III-1) and the thermosetting film for forming a protective film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0112] When using a colorant (I), the content of the colorant (I) in the thermosetting protective film-forming film may be adjusted appropriately depending on the purpose. For example, by adjusting the content of the colorant (I) in the thermosetting protective film-forming film and adjusting the light (355 nm) transmittance of the thermosetting protective film-forming film, the visibility of the print when laser printing is performed on the thermosetting protective film-forming film or the protective film can be adjusted. Furthermore, adjusting the content of the colorant (I) in the thermosetting protective film-forming film can improve the design of the protective film or make grinding marks on the backside of the semiconductor wafer less visible. Taking these points into consideration, the ratio of the content of the colorant (I) in the composition (III-1) to the total content of all components other than the solvent (i.e., the ratio of the content of the colorant (I) in the thermosetting protective film-forming film to the total mass of the thermosetting protective film-forming film) is preferably 0.05 to 12 mass%, more preferably 0.05 to 9 mass%, and particularly preferably 0.1 to 7 mass%. When the ratio is equal to or greater than the lower limit, the effect of using the colorant (I) is more pronounced, and when the ratio is equal to or less than the upper limit, excessive use of the colorant (I) is suppressed.

[0113] [General Purpose Additives (J)] The composition (III-1) and the thermosetting film for forming a protective film may contain a general-purpose additive (J) within the range that does not impair the effects of the present invention. The general-purpose additive (J) may be a known one and can be selected arbitrarily depending on the purpose, and is not particularly limited. Preferred examples thereof include plasticizers, antistatic agents, antioxidants, gettering agents, and ultraviolet absorbers.

[0114] The general-purpose additive (J) contained in the composition (III-1) and the thermosetting protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily. The content of the composition (III-1) and the general-purpose additive (J) in the thermosetting protective film-forming film is not particularly limited and may be appropriately selected depending on the purpose.

[0115] [solvent] The composition (III-1) preferably further contains a solvent, which makes the composition (III-1) easier to handle. In this specification, unless otherwise specified, the term "solvent" is used to refer to a concept that includes not only a substance that dissolves a target component, but also a dispersion medium that disperses the target component.

[0116] The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The composition (III-1) may contain one or more solvents, and when two or more solvents are contained, the combination and ratio thereof can be selected arbitrarily.

[0117] More preferred examples of the solvent contained in composition (III-1) include methyl ethyl ketone, toluene, ethyl acetate, etc., from the viewpoint of enabling the components contained in composition (III-1) to be mixed more uniformly.

[0118] The content of the solvent in the composition (III-1) is not particularly limited, and may be appropriately selected depending on, for example, the types of components other than the solvent.

[0119] <Method for producing a thermosetting protective film-forming composition> A thermosetting composition for forming a protective film such as composition (III-1) can be obtained by blending the components that constitute it. The thermosetting composition for forming a protective film can be produced by the same method as the pressure-sensitive adhesive composition described above, except that the types of ingredients used are different.

[0120] ◎ Energy ray curable protective film The curing conditions when the energy ray-curable film for forming a protective film is attached to the desired location on the workpiece and cured with energy rays to form a protective film are not particularly limited as long as the protective film is cured to a degree that allows it to fully exhibit its functions, and may be selected appropriately depending on the type of energy ray-curable film for forming a protective film. For example, the irradiance of the energy ray during energy ray curing of the energy ray-curable protective film-forming film is 120 to 280 mW / cm 2 The amount of energy rays during the curing is preferably 100 to 1000 mJ / cm. 2 It is preferable that:

[0121] The energy ray-curable protective film-forming film may, for example, be one containing an energy ray-curable component (a), and preferably one containing an energy ray-curable component (a) and a filler. In the energy ray-curable protective film-forming film, the energy ray-curable component (a) is preferably uncured and has adhesive properties, and more preferably uncured and has adhesive properties.

[0122] <Energy ray-curable protective film-forming composition (IV-1)> A preferred example of the energy ray-curable protective film-forming composition is energy ray-curable protective film-forming composition (IV-1) (sometimes abbreviated herein simply as "composition (IV-1)") containing the energy ray-curable component (a).

[0123] [Energy ray curable component (a)] The energy ray-curable component (a) is a component that is cured by irradiation with energy rays, and it imparts film-forming properties, flexibility, etc. to the energy ray-curable protective film-forming film, and is also a component that forms a hard protective film after curing. Examples of the energy ray-curable component (a) include a polymer (a1) having an energy ray-curable group and a weight-average molecular weight of 80,000 to 2,000,000, and a compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000. The polymer (a1) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

[0124] (Polymer (a1) having an energy ray-curable group and a weight-average molecular weight of 80,000 to 2,000,000) Examples of the polymer (a1) having an energy ray-curable group and a weight average molecular weight of 80,000 to 2,000,000 include an acrylic resin (a1-1) obtained by reacting an acrylic polymer (a11) having a functional group capable of reacting with a group possessed by another compound with an energy ray-curable compound (a12) having a group reactive with the functional group and an energy ray-curable group such as an energy ray-curable double bond.

[0125] Examples of the functional group capable of reacting with a group possessed by another compound include a hydroxyl group, a carboxy group, an amino group, a substituted amino group (a group in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom), an epoxy group, etc. However, from the viewpoint of preventing corrosion of circuits of a workpiece or a processed workpiece, etc., it is preferable that the functional group be a group other than a carboxy group. Among these, the functional group is preferably a hydroxyl group.

[0126] Acrylic polymer having functional groups (a11) The acrylic polymer (a11) having a functional group may be, for example, a polymer obtained by copolymerizing an acrylic monomer having the functional group with an acrylic monomer not having the functional group. In addition to these monomers, the acrylic polymer may also be a polymer obtained by copolymerizing a monomer other than the acrylic monomer (a non-acrylic monomer). The acrylic polymer (a11) may be a random copolymer or a block copolymer, and known methods can be used for the polymerization method.

[0127] Examples of the acrylic monomer having a functional group include a hydroxyl group-containing monomer, a carboxy group-containing monomer, an amino group-containing monomer, a substituted amino group-containing monomer, and an epoxy group-containing monomer.

[0128] 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 not having a (meth)acryloyl skeleton) such as vinyl alcohol and allyl alcohol.

[0129] Examples of the carboxy group-containing monomer include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; 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 (meth)acrylic acid carboxyalkyl esters such as 2-carboxyethyl methacrylate.

[0130] The acrylic monomer having a functional group is preferably a hydroxyl group-containing monomer.

[0131] The acrylic monomer having a functional group that constitutes the acrylic polymer (a11) may be of one type or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily.

[0132] Examples of the acrylic monomer not having a 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, and isopropyl (meth)acrylate. Examples of alkyl (meth)acrylate esters include those in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms, such as sononyl, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl (meth)acrylate (stearyl (meth)acrylate).

[0133] Examples of the acrylic monomer not having a functional group include alkoxyalkyl group-containing (meth)acrylic acid esters such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate; (meth)acrylic acid esters having an aromatic group, including (meth)acrylic acid aryl esters such as phenyl (meth)acrylate; non-crosslinkable (meth)acrylamide and derivatives thereof; and non-crosslinkable tertiary amino group-containing (meth)acrylic acid esters such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

[0134] The acrylic monomer having no functional group constituting the acrylic polymer (a11) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof can be selected arbitrarily.

[0135] Examples of the non-acrylic monomer include olefins such as ethylene and norbornene; vinyl acetate; and styrene. The non-acrylic monomer constituting the acrylic polymer (a11) may be of one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof can be selected arbitrarily.

[0136] In the acrylic polymer (a11), the proportion (content) of the structural units derived from the acrylic monomer having the functional group relative to the total amount of structural units constituting the acrylic polymer (a11) is preferably 0.1 to 50 mass%, more preferably 1 to 40 mass%, and particularly preferably 3 to 30 mass%. When the proportion is within this range, the content of the energy ray-curable group in the acrylic resin (a1-1) obtained by copolymerization of the acrylic polymer (a11) and the energy ray-curable compound (a12) can easily adjust the degree of curing of the protective film within a preferred range.

[0137] The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof can be selected arbitrarily.

[0138] In the composition (IV-1), the proportion of the content of the acrylic resin (a1-1) relative to the total content of components other than the solvent (i.e., the proportion of the content of the acrylic resin (a1-1) relative to the total mass of the energy ray-curable protective film-forming film) is preferably 1 to 70 mass%, more preferably 5 to 60 mass%, and particularly preferably 10 to 50 mass%.

[0139] Energy ray curable compounds (a12) The energy ray-curable compound (a12) preferably has one or more groups selected from the group consisting of an isocyanate group, an epoxy group, and a carboxy group as a group reactive with the functional group of the acrylic polymer (a11), and more preferably has an isocyanate group as the group. For example, when the energy ray-curable compound (a12) has an isocyanate group as the group, the isocyanate group easily reacts with the hydroxyl group of the acrylic polymer (a11) having the hydroxyl group as the functional group.

[0140] The number of energy ray-curable groups that the energy ray-curable compound (a12) has in one molecule is not particularly limited and can be appropriately selected in consideration of, for example, the physical properties required for the target protective film, such as the shrinkage rate. For example, the energy ray-curable compound (a12) preferably has 1 to 5, and more preferably 1 to 3, energy ray-curable groups in one molecule.

[0141] Examples of the energy ray-curable compound (a12) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate; an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate; Examples thereof include an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate. Among these, the energy ray-curable compound (a12) is preferably 2-methacryloyloxyethyl isocyanate.

[0142] The energy ray-curable compound (a12) constituting the acrylic resin (a1-1) may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof can be selected arbitrarily.

[0143] In the acrylic resin (a1-1), the ratio of the content of the energy ray-curable groups derived from the energy ray-curable compound (a12) to the content of the functional groups derived from the acrylic polymer (a11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. When the content ratio is within this range, the adhesive strength of the cured product of the energy ray-curable protective film-forming film is increased. When the energy ray-curable compound (a12) is a monofunctional compound (having one such group per molecule), the upper limit of the content ratio is 100 mol%, but when the energy ray-curable compound (a12) is a polyfunctional compound (having two or more such groups per molecule), the upper limit of the content ratio may exceed 100 mol%.

[0144] The weight average molecular weight (Mw) of the polymer (a1) is preferably 100,000 to 2,000,000, and more preferably 300,000 to 1,500,000. Here, the "weight average molecular weight" is as explained above.

[0145] When the polymer (a1) is at least partially crosslinked with a crosslinking agent, the polymer (a1) may be crosslinked at the group reactive with the crosslinking agent by polymerization of a monomer that does not correspond to any of the above-mentioned monomers described as constituting the acrylic polymer (a11) and has a group reactive with the crosslinking agent, or may be crosslinked at a group reactive with the functional group derived from the energy ray-curable compound (a12).

[0146] The polymer (a1) contained in the composition (IV-1) and the energy ray-curable protective film-forming film may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0147] (Compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000) The energy ray-curable group in the compound (a2) having an energy ray-curable group and a molecular weight of 100 to 80,000 includes a group containing an energy ray-curable double bond, and preferred examples thereof include a (meth)acryloyl group and a vinyl group.

[0148] The compound (a2) is not particularly limited as long as it satisfies the above conditions, and examples thereof include a low-molecular-weight compound having an energy ray-curable group, an epoxy resin having an energy ray-curable group, and a phenolic resin having an energy ray-curable group.

[0149] Among the compounds (a2), examples of the low molecular weight compound having an energy ray-curable group include polyfunctional monomers or oligomers, and acrylate compounds having a (meth)acryloyl group are preferred. Examples of the acrylate compounds include 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxydiethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloxypolypropoxy)phenyl]propane, tricyclodecane dimethanol di(meth)acrylate, 1,10-decanediol ... Bifunctional (meth)acrylates such as 6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloxyethoxy)phenyl]propane, neopentyl glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, and 2-hydroxy-1,3-di(meth)acryloxypropane; polyfunctional (meth)acrylates such as tris(2-(meth)acryloxyethyl)isocyanurate, ε-caprolactone-modified tris-(2-(meth)acryloxyethyl)isocyanurate, ethoxylated glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; Examples include polyfunctional (meth)acrylate oligomers such as urethane (meth)acrylate oligomers.

[0150] Among the compounds (a2), examples of epoxy resins having an energy ray-curable group and phenolic resins having an energy ray-curable group that can be used include those described in paragraph 0043 of JP 2013-194102 A. Although such resins also fall under the category of resins constituting the thermosetting component described below, they are treated as the compound (a2) in the present invention.

[0151] The weight average molecular weight of the compound (a2) is preferably 100 to 30,000, and more preferably 300 to 10,000.

[0152] The compound (a2) contained in the composition (IV-1) and the energy ray-curable protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0153] [Polymer (b) having no energy ray-curable group] When the composition (IV-1) and the energy ray-curable protective film-forming film contain the compound (a2) as the energy ray-curable component (a), they preferably also contain a polymer (b) that does not have an energy ray-curable group. The polymer (b) may be at least partially crosslinked with a crosslinking agent, or may not be crosslinked.

[0154] Examples of the polymer (b) having no energy ray-curable group include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber-based resins, and acrylic urethane resins. Among these, the polymer (b) is preferably an acrylic polymer (hereinafter sometimes abbreviated as "acrylic polymer (b-1)").

[0155] The acrylic polymer (b-1) may be a known polymer, for example, a homopolymer of one type of acrylic monomer, a copolymer of two or more types of acrylic monomers, or a copolymer of one or more types of acrylic monomers and one or more types of monomers other than the acrylic monomers (non-acrylic monomers).

[0156] Examples of the acrylic monomer constituting the acrylic polymer (b-1) include (meth)acrylic acid alkyl esters, (meth)acrylic acid esters having a cyclic skeleton, glycidyl group-containing (meth)acrylic acid esters, hydroxyl group-containing (meth)acrylic acid esters, substituted amino group-containing (meth)acrylic acid esters, etc. Here, the "substituted amino group" is as explained above.

[0157] Examples of the (meth)acrylic acid alkyl ester include the same as the acrylic monomer not having a functional group (e.g., a (meth)acrylic acid alkyl ester in which the alkyl group constituting the alkyl ester has a chain structure containing 1 to 18 carbon atoms) that constitutes the acrylic polymer (a11) described above.

[0158] Examples of the (meth)acrylic acid ester having a cyclic skeleton include (meth)acrylic acid cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate; (Meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester; (Meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyloxyethyl ester are included.

[0159] Examples of the glycidyl group-containing (meth)acrylic acid ester include glycidyl (meth)acrylate. Examples of the hydroxyl group-containing (meth)acrylic acid ester 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)acrylic acid ester include N-methylaminoethyl (meth)acrylate.

[0160] Examples of the non-acrylic monomer that constitutes the acrylic polymer (b-1) include olefins such as ethylene and norbornene; vinyl acetate; and styrene.

[0161] The polymer (b) having no energy ray-curable group and at least a portion of which is crosslinked with a crosslinking agent may be, for example, a polymer in which a reactive functional group in the polymer (b) has reacted with a crosslinking agent. The reactive functional group may be appropriately selected depending on the type of crosslinking agent, and is not particularly limited. For example, when the crosslinking agent is a polyisocyanate compound, examples of the reactive functional group include a hydroxyl group, a carboxyl group, an amino group, etc., and among these, a hydroxyl group, which has high reactivity with an isocyanate group, is preferred. When the crosslinking agent is an epoxy compound, examples of the reactive functional group include a carboxyl group, an amino group, an amide group, etc., and among these, a carboxyl group, which has high reactivity with an epoxy group, is preferred. However, from the viewpoint of preventing corrosion of the circuit of the workpiece or the processed workpiece, it is preferable that the reactive functional group be a group other than a carboxyl group.

[0162] Examples of the polymer (b) having a reactive functional group but not having an energy ray-curable group include those obtained by polymerizing at least a monomer having the reactive functional group. In the case of an acrylic polymer (b-1), one or both of the acrylic monomers and non-acrylic monomers listed as the monomers constituting the polymer may have the reactive functional group. Examples of the polymer (b) having a hydroxyl group as a reactive functional group include those obtained by polymerizing a hydroxyl group-containing (meth)acrylic acid ester, and also those obtained by polymerizing a monomer in which one or more hydrogen atoms in the acrylic monomers or non-acrylic monomers listed above are substituted with the reactive functional group.

[0163] In the polymer (b) having a reactive functional group, the proportion (content) of the amount of the structural units derived from the monomer having a reactive functional group relative to the total amount of the structural units constituting the polymer (b) is preferably 1 to 20 mass%, more preferably 2 to 10 mass%. When the proportion is in this range, the degree of crosslinking in the polymer (b) becomes a more preferable range.

[0164] The weight-average molecular weight (Mw) of the polymer (b) having no energy ray-curable group is preferably 10,000 to 2,000,000, more preferably 100,000 to 1,500,000, in order to improve the film-forming properties of the composition (IV-1). Here, the "weight-average molecular weight" is as explained above.

[0165] The polymer (b) not having an energy ray-curable group contained in the composition (IV-1) and the energy ray-curable protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0166] The composition (IV-1) may contain either or both of the polymer (a1) and the compound (a2). When the composition (IV-1) contains the compound (a2), it preferably further contains a polymer (b) having no energy ray-curable group, and in this case, it is also preferable that the composition (IV-1) further contains the (a1). Alternatively, the composition (IV-1) may not contain the compound (a2), but may contain both the polymer (a1) and the polymer (b) having no energy ray-curable group.

[0167] When the composition (IV-1) contains the polymer (a1), the compound (a2), and the polymer (b) having no energy ray-curable group, the content of the compound (a2) in the composition (IV-1) is preferably 10 to 400 parts by mass, and more preferably 30 to 350 parts by mass, per 100 parts by mass of the total content of the polymer (a1) and the polymer (b) having no energy ray-curable group.

[0168] In composition (IV-1), the ratio of the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group to the total content of components other than the solvent (i.e., the ratio of the total content of the energy ray-curable component (a) and the polymer (b) having no energy ray-curable group to the total mass of the energy ray-curable protective film-forming film) is preferably 5 to 90 mass%, more preferably 10 to 80 mass%, and particularly preferably 20 to 70 mass%. When the ratio of the content of the energy ray-curable component is within this range, the energy ray curability of the energy ray-curable protective film-forming film becomes better.

[0169] In addition to the energy ray-curable component, the composition (IV-1) may contain, depending on the purpose, one or more selected from the group consisting of a thermosetting component, a filler, a coupling agent, a crosslinking agent, a photopolymerization initiator, a colorant, and a general-purpose additive.

[0170] The thermosetting component, filler, coupling agent, crosslinking agent, photopolymerization initiator, colorant, and general-purpose additive in composition (IV-1) may be the same as the thermosetting component (B), filler (D), coupling agent (E), crosslinking agent (F), photopolymerization initiator (H), colorant (I), and general-purpose additive (J) in composition (III-1), respectively.

[0171] For example, by using the composition (IV-1) containing the energy ray-curable component and the thermosetting component, the adhesive strength of the energy ray-curable protective film-forming film formed to the adherend is improved by heating, and the strength of the protective film formed from this energy ray-curable protective film-forming film is also improved. Furthermore, by using the composition (IV-1) containing the energy ray-curable component and the colorant, the energy ray-curable film for forming a protective film formed therefrom exhibits the same effects as in the case where the thermosetting film for forming a protective film described above contains the colorant (I).

[0172] In the composition (IV-1), the thermosetting component, filler, coupling agent, crosslinking agent, photopolymerization initiator, colorant, and general-purpose additive may each be used alone or in combination of two or more kinds. When two or more kinds are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0173] The contents of the thermosetting component, filler, coupling agent, crosslinking agent, photopolymerization initiator, colorant, and general-purpose additive in the composition (IV-1) may be appropriately adjusted depending on the purpose, and are not particularly limited.

[0174] Composition (IV-1) preferably further contains a solvent, since dilution improves its handling properties. The solvent contained in the composition (IV-1) may be, for example, the same as the solvent in the composition (III-1). The composition (IV-1) may contain only one type of solvent, or two or more types of solvents. The content of the solvent in the composition (IV-1) is not particularly limited, and may be appropriately selected depending on, for example, the types of components other than the solvent.

[0175] <Method for producing energy ray-curable protective film-forming composition> The energy ray-curable protective film-forming composition such as composition (IV-1) can be obtained by blending the components that constitute it. The energy ray-curable protective film-forming composition can be produced, for example, by the same method as for the pressure-sensitive adhesive composition described above, except that the types of blended components are different.

[0176] ◎Non-curing protective film forming film A preferred non-curable protective film-forming film is, for example, one containing a thermoplastic resin and a filler.

[0177] <Non-curable protective film forming composition (V-1)> A preferred example of a non-curable protective film-forming composition is a non-curable protective film-forming composition (V-1) (sometimes abbreviated herein simply as "composition (V-1)") containing the above-mentioned thermoplastic resin and a filler.

[0178] [Thermoplastic resin] The thermoplastic resin is not particularly limited. More specifically, examples of the thermoplastic resin include the same non-curable resins as those listed as components contained in the above-mentioned composition (III-1), such as acrylic resins, polyesters, polyurethanes, phenoxy resins, polybutenes, polybutadienes, and polystyrenes.

[0179] The thermoplastic resin contained in composition (V-1) and the non-curable protective film-forming film may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0180] In composition (V-1), the ratio of the content of the thermoplastic resin to the total content of components other than the solvent (i.e., the ratio of the content of the thermoplastic resin in the non-curable protective film-forming film to the total mass of the non-curable protective film-forming film) is preferably 25 to 75 mass%.

[0181] [Filling material] The non-curable film for forming a protective film containing a filler exhibits the same effects as the thermosetting film for forming a protective film containing the filler (D).

[0182] Examples of the filler contained in the composition (V-1) and the film for forming a non-curable protective film include the same filler (D) contained in the composition (III-1) and the film for forming a thermosetting protective film.

[0183] The composition (V-1) and the non-curable protective film-forming film may contain one type of filler or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0184] In composition (V-1), the ratio of the filler content to the total content of all components other than the solvent (i.e., the ratio of the filler content in the non-curable protective film-forming film to the total mass of the film for forming a non-curable protective film) is preferably 25 to 75 mass%. By having this ratio in this range, it becomes easier to adjust the thermal expansion coefficient of the non-curable protective film-forming film (i.e., the protective film), as in the case of using composition (III-1).

[0185] The composition (V-1) may contain other components in addition to the thermoplastic resin and filler, depending on the purpose. The other components are not particularly limited and can be selected arbitrarily depending on the purpose. For example, by using the composition (V-1) containing the thermoplastic resin and the colorant, the non-curable film for forming a protective film (in other words, the protective film) formed exhibits the same effects as when the thermosetting film for forming a protective film described above contains the colorant (I).

[0186] In the composition (V-1), the other components may be used singly or in combination of two or more kinds. When two or more kinds are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0187] The content of the other components in the composition (V-1) may be adjusted appropriately depending on the purpose, and is not particularly limited.

[0188] Composition (V-1) preferably further contains a solvent, since dilution improves its handling properties. Examples of the solvent contained in the composition (V-1) include the same solvents as those in the above-mentioned composition (III-1). The composition (V-1) may contain only one type of solvent, or two or more types of solvents. The content of the solvent in the composition (V-1) is not particularly limited, and may be appropriately selected depending on, for example, the types of components other than the solvent.

[0189] <Method for producing a composition for forming a non-curable protective film> A non-curable protective film-forming composition such as composition (V-1) can be obtained by blending the components that constitute it. The non-curable protective film-forming composition can be produced by the same method as the pressure-sensitive adhesive composition described above, except that the types of ingredients used are different.

[0190] So far, we have mainly explained the case where a film for forming a protective film is used in combination with the support sheet to form a composite sheet for forming a protective film, but the film for forming a protective film may also be used without being used in combination with the support sheet, and without forming a composite sheet for forming a protective film. For example, after a protective film-forming film that does not constitute a composite sheet for forming a protective film is attached to a location on a workpiece, laser light can be irradiated directly from the outside onto the protective film-forming film or the protective film, thereby enabling good printing on the protective film-forming film or the protective film. The printing process in such a case will be described in detail later. When printing is performed directly on the protective film-forming film or the protective film without using a support sheet, the printability is usually equal to or better than when printing is performed through a support sheet. The film for forming a protective film when used without constituting a composite sheet for forming a protective film may be the same as the film for forming a protective film when used by constituting a composite sheet for forming a protective film. When a protective film forming film that does not constitute a composite sheet for forming a protective film is attached to a workpiece, a release film may be provided on the surface of the protective film forming film opposite to the surface that is attached to the workpiece, and in this case, it is preferable to remove the release film before irradiating it with laser light.

[0191] ◇Composite sheet for forming protective film A composite sheet for forming a protective film according to one embodiment of the present invention comprises a support sheet and a film for forming a protective film provided on one side of the support sheet, wherein the support sheet has a light (355 nm) transmittance of 20% or more, and the film for forming a protective film is the film for forming a protective film according to one embodiment of the present invention described above (i.e., the film for forming a protective film has a light (355 nm) transmittance of 60% or less).

[0192] The film for forming a protective film in the composite sheet for forming a protective film of this embodiment is curable or non-curable, as described above. The composite sheet for forming a protective film can be used to print on the film for forming a protective film or the protective film therein by irradiating laser light from the outside of the support sheet side of the composite sheet for forming a protective film through the support sheet.

[0193] In the composite sheet for forming a protective film of this embodiment, the support sheet has a high transmittance for light (355 nm) and the film for forming a protective film has a low transmittance for light (355 nm), so even when irradiated with laser light having a shorter wavelength than conventional laser light (for example, a wavelength of 355 nm), printing can be performed well on the film for forming a protective film or the protective film. Furthermore, this printing can be clearly seen through the support sheet. The support sheet will be described in detail below.

[0194] ◎Support sheet The support sheet has a transmittance of 20% or more for light with a wavelength of 355 nm (light (355 nm)). The support sheet can be used to fix a workpiece having the protective film-forming film or protective film at any location. For example, if the workpiece is a semiconductor wafer, the support sheet can be used to fix a semiconductor wafer having the protective film-forming film or protective film on its back surface.

[0195] Examples of the support sheet include one comprising a substrate and a pressure-sensitive adhesive layer provided on one side of the substrate; one consisting of a substrate; one comprising a substrate, a pressure-sensitive adhesive layer provided on one side of the substrate, and an intermediate layer provided on the surface of the pressure-sensitive adhesive layer opposite the substrate side; one comprising a substrate and an intermediate layer provided on one side of the substrate, etc. When the support sheet comprises a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is disposed between the substrate and the film for forming a protective film in the composite sheet for forming a protective film described below.

[0196] When a support sheet having a substrate and an adhesive layer is used, the adhesive strength or adhesion between the support sheet and the film for forming a protective film in the composite sheet for forming a protective film can be easily adjusted. When a support sheet made of a substrate is used, the composite sheet for forming a protective film can be produced at low cost. When a support sheet including a substrate, a pressure-sensitive adhesive layer, and an intermediate layer is used, new functions can be imparted to the support sheet or the composite sheet for forming a protective film, and the adhesive strength or adhesion between the support sheet and the film for forming a protective film can be adjusted more easily than in the case of the pressure-sensitive adhesive layer described above.

[0197] The support sheet has high light (355 nm) transmittance. Therefore, by irradiating the protective film-forming film or protective film in the composite sheet for forming a protective film with laser light having a shorter wavelength than conventional laser light, such as a wavelength of 355 nm, from the outside of the support sheet side of the composite sheet for forming a protective film through the support sheet, it is possible to print well on the protective film-forming film or protective film. Furthermore, this printing can be clearly seen through the support sheet from the outside of the support sheet side of the composite sheet for forming a protective film.

[0198] The transmittance of the support sheet to light (355 nm) is preferably 23% or more, and may be, for example, any one of 40% or more, 50% or more, 60% or more, 70% or more, and 80% or more. When the transmittance of the support sheet is equal to or greater than the lower limit, the printability of the film for forming a protective film or the protective film and the print visibility thereof are further improved.

[0199] The upper limit of the transmittance of the support sheet for light (355 nm) is not particularly limited and may be, for example, 100%. For example, a support sheet having a transmittance of 97% or less is easier to manufacture.

[0200] The transmittance of the support sheet for light (355 nm) can be adjusted appropriately within a range set by arbitrarily combining any of the above-mentioned lower and upper limits. For example, in one embodiment, the transmittance of the support sheet is preferably 20 to 97%, more preferably 23 to 97%, and may be, for example, any of 40 to 97%, 50 to 97%, 60 to 97%, 70 to 97%, and 80 to 97%. However, these are just examples of the transmittance of the support sheet.

[0201] ○Base material The substrate is in the form of a sheet or film and is transparent to light (355 nm).

[0202] Examples of materials constituting the substrate include various resins. Examples of the resin include polyolefins such as low-density polyethylene (LDPE) and polypropylene (PP); ethylene-methacrylic acid copolymer (EMAA); polyvinyl chloride (PVC); polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); polyacrylic esters; and polycarbonate (PC).

[0203] The resin constituting the substrate may be one type only, or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily.

[0204] The substrate may consist of one layer (single layer), or may consist of two or more layers. When the substrate consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0205] The thickness of the substrate is preferably 40 to 300 μm, more preferably 40 to 100 μm. When the thickness of the substrate is in this range, the flexibility of the composite sheet for forming a protective film and the attachability to a workpiece or a processed workpiece are further improved. Here, the "thickness of the substrate" means the thickness of the entire substrate, and for example, the thickness of a substrate consisting of multiple layers means the total thickness of all layers that make up the substrate.

[0206] The substrate preferably has a high thickness accuracy, i.e., a thickness variation that is suppressed regardless of the location. Among the above-mentioned constituent materials, examples of materials that can be used to form a substrate with such a high thickness accuracy include polyolefin and polyethylene terephthalate.

[0207] In addition to the main constituent materials such as the resin, the substrate may contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and softeners (plasticizers). For example, the transmittance of light (355 nm) through the substrate can be easily adjusted by adjusting whether or not the substrate contains a filler or colorant, or by adjusting the content of a filler or colorant if the substrate contains one.

[0208] The substrate preferably does not contain, or contains only a small amount of, a component that absorbs light (355 nm). Examples of the component that absorbs light (355 nm) include a resin having a benzene ring skeleton (i.e., a group having a structure in which 1 to 6 hydrogen atoms have been removed from benzene) or a compound having an aromatic cyclic group, such as a colorant.

[0209] The substrate may contain a specific range of components (for example, a resin) to provide adhesiveness on at least one surface.

[0210] The optical properties of the substrate need only be such that the support sheet satisfies the condition of transmittance of the light (355 nm) described above. For example, as mentioned above, the support sheet may be composed of only the substrate, so the transmittance of the substrate to light (355 nm) may be the same as the transmittance of the support sheet to light (355 nm) exemplified above.

[0211] Furthermore, for the same reasons as in the case of the transmittance of light (355 nm) of the support sheet described above, the transmittance of light (355 nm) of the substrate may be, for example, any of 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, and 90% or more.

[0212] For the same reason as in the case of the transmittance of light (355 nm) of the support sheet described above, the upper limit of the transmittance of light (355 nm) of the substrate is not particularly limited and may be, for example, 100%. For example, a substrate having a transmittance of 97% or less is easier to manufacture or obtain.

[0213] The transmittance of the substrate to light (355 nm) can be appropriately adjusted within a range set by arbitrarily combining any of the above-mentioned lower limit values ​​and upper limit values. For example, in one embodiment, the transmittance of the substrate may be any of 40 to 97%, 50 to 97%, 60 to 97%, 70 to 97%, 80 to 97%, and 90 to 97%. However, these are just examples of the transmittance of the substrate.

[0214] In order to improve adhesion to a layer (e.g., a pressure-sensitive adhesive layer, a film for forming a protective film, etc.) formed thereon, the surface of the substrate may be subjected to a roughening treatment such as sandblasting or solvent treatment, or an oxidation treatment such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone or ultraviolet irradiation treatment, flame treatment, chromic acid treatment, or hot air treatment. The surface of the substrate may also be treated with a primer. The substrate may also have an antistatic coating layer; a layer that prevents the substrate from adhering to other sheets or to an adsorption table when the composite sheet for forming a protective film is stacked and stored; or the like. The substrate may also have a release treatment layer on its surface.

[0215] The substrate can be produced by a known method. For example, a substrate containing a resin can be produced by molding a resin composition containing the resin.

[0216] Adhesive layer The pressure-sensitive adhesive layer is in the form of a sheet or film, and is transparent to light (355 nm).

[0217] The pressure-sensitive adhesive layer contains a pressure-sensitive 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, with acrylic resins being preferred.

[0218] In this specification, the term "adhesive resin" includes both a resin having adhesive properties and a resin having adhesive properties. For example, the adhesive resin includes not only resins that are adhesive by themselves, but also resins that become adhesive when used in combination with other components such as additives, and resins that become adhesive in the presence of a trigger such as heat or water.

[0219] The adhesive layer may consist of one layer (single layer), or may consist of two or more layers. When it consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0220] The thickness of the adhesive layer is preferably 1 to 14 μm, more preferably 2 to 12 μm, and may be, for example, 3 to 8 μm. When the thickness of the adhesive layer is equal to or greater than the lower limit, the effect of providing the adhesive layer is more pronounced. When the thickness of the adhesive layer is equal to or less than the upper limit, printing can be performed more effectively on the film for forming a protective film or the protective film in the composite sheet for forming a protective film. Furthermore, this printing can be more easily viewed through the support sheet from the outside of the support sheet side of the composite sheet for forming a protective film. Here, "thickness of the adhesive layer" means the thickness of the entire adhesive layer, for example, the thickness of an adhesive layer consisting of multiple layers means the total thickness of all layers that make up the adhesive layer.

[0221] The optical properties of the pressure-sensitive adhesive layer may be such that the support sheet satisfies the condition of transmittance of the light (355 nm) described above.

[0222] The pressure-sensitive adhesive layer may be formed using an energy ray-curable pressure-sensitive adhesive or a non-energy ray-curable pressure-sensitive adhesive. That is, the pressure-sensitive adhesive layer may be either energy ray-curable or non-energy ray-curable. The energy ray-curable pressure-sensitive adhesive layer can easily adjust its physical properties before and after curing. For example, by curing the energy ray-curable pressure-sensitive adhesive layer before picking up the semiconductor chip with a protective film or the semiconductor chip with a protective film-forming film described below, these semiconductor chips can be more easily picked up.

[0223] <<Adhesive composition>> The pressure-sensitive adhesive layer can be formed using a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive. For example, the pressure-sensitive adhesive composition can be applied to a surface on which the pressure-sensitive adhesive layer is to be formed, and then dried as necessary to form the pressure-sensitive adhesive layer at the desired location. The ratio of the contents of the components that do not vaporize at room temperature in the pressure-sensitive adhesive composition is usually the same as the ratio of the contents of the components in the pressure-sensitive adhesive layer.

[0224] The pressure-sensitive adhesive composition can be applied, for example, by the same method as in the case of applying the above-mentioned composition for forming a protective film.

[0225] The drying conditions for the pressure-sensitive adhesive composition are not particularly limited. When the pressure-sensitive adhesive composition contains a solvent described below, it is preferably dried by heating. The pressure-sensitive adhesive composition containing the solvent is preferably dried, for example, at 70 to 130°C for 10 seconds to 5 minutes.

[0226] When a pressure-sensitive adhesive layer is provided on a substrate, for example, a pressure-sensitive adhesive composition may be applied to the substrate and dried as necessary to laminate the pressure-sensitive adhesive layer on the substrate. When a pressure-sensitive adhesive layer is provided on a substrate, for example, a pressure-sensitive adhesive composition may be applied to a release film and dried as necessary to form a pressure-sensitive adhesive layer on the release film, and the exposed surface of this pressure-sensitive adhesive layer may be attached to one surface of the substrate to laminate the pressure-sensitive adhesive layer on the substrate. In this case, the release film may be removed at any time during the manufacturing process or use of the composite sheet for forming a protective film.

[0227] When the adhesive layer is energy ray-curable, examples of the energy ray-curable adhesive composition include adhesive composition (I-1) containing a non-energy ray-curable adhesive resin (I-1a) (hereinafter sometimes abbreviated as "adhesive resin (I-1a)") and an energy ray-curable compound; adhesive composition (I-2) containing an energy ray-curable adhesive resin (I-2a) (hereinafter sometimes abbreviated as "adhesive resin (I-2a)") in which an unsaturated group has been introduced into the side chain of the adhesive resin (I-1a); adhesive composition (I-3) containing the adhesive resin (I-2a) and an energy ray-curable compound; and the like.

[0228] When the pressure-sensitive adhesive layer is non-energy ray curable, examples of the non-energy ray curable pressure-sensitive adhesive composition include the pressure-sensitive adhesive composition (I-4) containing the pressure-sensitive adhesive resin (I-1a).

[0229] [Adhesive resin (I-1a)] The adhesive resin (I-1a) in the adhesive composition (I-1), adhesive composition (I-2), adhesive composition (I-3) and adhesive composition (I-4) (hereinafter, these adhesive compositions are collectively abbreviated as "adhesive compositions (I-1) to (I-4)") is preferably an acrylic resin.

[0230] Examples of the acrylic resin include acrylic polymers having at least a structural unit derived from a (meth)acrylic acid alkyl ester. The (meth)acrylic acid alkyl ester may be, for example, one in which the alkyl group constituting the alkyl ester has 1 to 20 carbon atoms, and the alkyl group is preferably linear or branched.

[0231] The acrylic polymer preferably further contains a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the (meth)acrylic acid alkyl ester. Examples of the functional group-containing monomer include those whose functional group reacts with a crosslinking agent described below to become a starting point for crosslinking, and those whose functional group reacts with an unsaturated group in an unsaturated group-containing compound described below to enable the introduction of an unsaturated group into a side chain of an acrylic polymer.

[0232] Examples of the functional group-containing monomer include hydroxyl group-containing monomers, carboxy group-containing monomers, amino group-containing monomers, and epoxy group-containing monomers.

[0233] The acrylic polymer may further contain structural units derived from other monomers in addition to the structural units derived from the alkyl (meth)acrylate ester and the structural units derived from the functional group-containing monomer. The other monomer is not particularly limited as long as it is copolymerizable with the (meth)acrylic acid alkyl ester or the like. Examples of the other monomers include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

[0234] In the pressure-sensitive adhesive compositions (I-1) to (I-4), the structural units contained in the acrylic resin such as the acrylic polymer may be of one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0235] In the acrylic polymer, the content of the structural units derived from functional group-containing monomers is preferably 1 to 35% by mass relative to the total amount of structural units.

[0236] The adhesive resin (I-1a) contained in the adhesive composition (I-1) or (I-4) may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0237] In the pressure-sensitive adhesive composition (I-1) or the pressure-sensitive adhesive composition (I-4), the content of the adhesive resin (I-1a) relative to the total mass of the pressure-sensitive adhesive composition (I-1) or the pressure-sensitive adhesive composition (I-4) is preferably 5 to 99 mass%.

[0238] [Adhesive resin (I-2a)] The adhesive resin (I-2a) in the adhesive compositions (I-2) and (I-3) can be obtained, for example, by reacting a functional group in the adhesive resin (I-1a) with an unsaturated group-containing compound having an energy ray-polymerizable unsaturated group.

[0239] The unsaturated group-containing compound is a compound that, in addition to the energy ray-polymerizable unsaturated group, further has a group that can bond to the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a). Examples of the energy ray-polymerizable unsaturated group include a (meth)acryloyl group, a vinyl group (ethenyl group), and an allyl group (2-propenyl group), and the (meth)acryloyl group is preferred. Examples of groups capable of bonding to functional groups in the adhesive resin (I-1a) include isocyanate groups and glycidyl groups capable of bonding to hydroxyl groups or amino groups, and hydroxyl groups and amino groups capable of bonding to carboxyl groups or epoxy groups.

[0240] Examples of the unsaturated group-containing compound include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

[0241] The adhesive resin (I-2a) contained in the adhesive composition (I-2) or (I-3) may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0242] In the pressure-sensitive adhesive composition (I-2) or (I-3), the content of the pressure-sensitive adhesive resin (I-2a) relative to the total mass of the pressure-sensitive adhesive composition (I-2) or (I-3) is preferably 5 to 99 mass %.

[0243] [Energy ray curable compounds] The energy ray-curable compound in the pressure-sensitive adhesive compositions (I-1) and (I-3) includes a monomer or oligomer having an energy ray-polymerizable unsaturated group and capable of being cured by irradiation with energy rays.

[0244] Among the energy ray-curable compounds, examples of the monomer include polyvalent (meth)acrylates such as trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol (meth)acrylate; urethane (meth)acrylate; polyester (meth)acrylate; polyether (meth)acrylate; and epoxy (meth)acrylate. Among the energy ray-curable compounds, examples of oligomers include oligomers obtained by polymerizing the above-exemplified monomers.

[0245] The pressure-sensitive adhesive composition (I-1) or (I-3) may contain only one type of energy ray-curable compound, or two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0246] In the pressure-sensitive adhesive composition (I-1), the content of the energy ray-curable compound is preferably 1 to 95 mass % relative to the total mass of the pressure-sensitive adhesive composition (I-1). In the pressure-sensitive adhesive composition (I-3), the content of the energy ray-curable compound is preferably 0.01 to 300 parts by mass relative to 100 parts by mass of the pressure-sensitive adhesive resin (I-2a).

[0247] [Crosslinking agent] When the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to a structural unit derived from a (meth)acrylic acid alkyl ester is used as the pressure-sensitive adhesive resin (I-1a), it is preferable that the pressure-sensitive adhesive composition (I-1) or (I-4) further contains a crosslinking agent. Furthermore, when the adhesive resin (I-2a) is, for example, an acrylic polymer having structural units derived from functional group-containing monomers similar to those in the adhesive resin (I-1a), the adhesive composition (I-2) or (I-3) may further contain a crosslinking agent.

[0248] The crosslinking agent reacts with the functional group to crosslink the adhesive resins (I-1a) together or the adhesive resins (I-2a) together, for example. Examples of crosslinking agents include isocyanate-based crosslinking agents (crosslinking agents having an isocyanate group) such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy-based crosslinking agents (crosslinking agents having a glycidyl group) such as ethylene glycol glycidyl ether; aziridine-based crosslinking agents (crosslinking agents having an aziridinyl group) such as hexa[1-(2-methyl)-aziridinyl]triphosphatriazine; metal chelate-based crosslinking agents (crosslinking agents having a metal chelate structure) such as aluminum chelate; and isocyanurate-based crosslinking agents (crosslinking agents having an isocyanuric acid skeleton).

[0249] The crosslinking agent contained in the pressure-sensitive adhesive composition (I-1), (I-2) or (I-4) may be one type or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0250] In the pressure-sensitive adhesive composition (I-1) or (I-4), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass, and may be, for example, either 0.01 to 35 parts by mass or 0.01 to 20 parts by mass, per 100 parts by mass of the pressure-sensitive adhesive resin (I-1a). In the pressure-sensitive adhesive composition (I-2) or (I-3), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass relative to 100 parts by mass of the pressure-sensitive adhesive resin (I-2a), and may be, for example, any one of 0.01 to 35 parts by mass, 0.01 to 20 parts by mass, and 0.01 to 10 parts by mass.

[0251] [Photopolymerization initiator] The pressure-sensitive adhesive compositions (I-1), (I-2) and (I-3) (hereinafter collectively referred to as "pressure-sensitive adhesive compositions (I-1) to (I-3)") may further contain a photopolymerization initiator. The pressure-sensitive adhesive compositions (I-1) to (I-3) containing a photopolymerization initiator undergo a sufficient curing reaction even when irradiated with relatively low-energy energy rays such as ultraviolet light.

[0252] 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, 2,2-dimethoxy-1,2-diphenylethan-1-one, and 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one; bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2,4,6-trimethylbenzoyl Examples of the compound include acylphosphine oxide compounds such as diphenylphosphine oxide; sulfide compounds such as benzyl phenyl sulfide and tetramethylthiuram monosulfide; α-ketol compounds such as 1-hydroxycyclohexyl phenyl ketone; azo compounds such as azobisisobutyronitrile; titanocene compounds such as titanocene; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as diacetyl; benzyl; dibenzyl; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; and quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone. As the photopolymerization initiator, for example, a photosensitizer such as an amine can also be used.

[0253] The photopolymerization initiators contained in the pressure-sensitive adhesive compositions (I-1) to (I-3) may be one type only, or two or more types, and when two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0254] In the pressure-sensitive adhesive composition (I-1), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the content of the energy ray-curable compound. In the pressure-sensitive adhesive composition (I-2), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass, and may be, for example, either 0.01 to 10 parts by mass or 0.01 to 5 parts by mass, relative to 100 parts by mass of the pressure-sensitive adhesive resin (I-2a). In the pressure-sensitive adhesive composition (I-3), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the total content of the pressure-sensitive adhesive resin (I-2a) and the energy ray-curable compound.

[0255] [Other additives] The pressure-sensitive adhesive compositions (I-1) to (I-4) may contain other additives that do not fall under any of the above-mentioned components, as long as the effects of the present invention are not impaired. Examples of the other additives include known additives such as antistatic agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, colorants (pigments, dyes), sensitizers, tackifiers, reaction retarders, and crosslinking accelerators (catalysts). The reaction retarder is, for example, a compound that inhibits the progress of an unintended crosslinking reaction in the pressure-sensitive adhesive compositions (I-1) to (I-4) during storage due to the action of a catalyst mixed in the pressure-sensitive adhesive compositions (I-1) to (I-4). Examples of the reaction retarder include a compound that forms a chelate complex by chelating with the catalyst, and more specifically, a compound that has two or more carbonyl groups (-C(=O)-) in one molecule.

[0256] The other additives contained in the pressure-sensitive adhesive compositions (I-1) to (I-4) may be one kind or two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be selected arbitrarily.

[0257] The content of other additives in the pressure-sensitive adhesive compositions (I-1) to (I-4) is not particularly limited and may be selected appropriately depending on the type of additive.

[0258] [solvent] The pressure-sensitive adhesive compositions (I-1) to (I-4) may contain a solvent, which improves the suitability of the pressure-sensitive adhesive compositions (I-1) to (I-4) for application to a surface to be coated.

[0259] The solvent is preferably 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; and alcohols such as 1-propanol and 2-propanol.

[0260] The pressure-sensitive adhesive compositions (I-1) to (I-4) may contain one kind of solvent or two or more kinds of solvents, and when two or more kinds of solvents are contained, the combination and ratio thereof can be selected arbitrarily.

[0261] The content of the solvent in the pressure-sensitive adhesive compositions (I-1) to (I-4) is not particularly limited and may be adjusted appropriately.

[0262] The pressure-sensitive adhesive layer and the pressure-sensitive adhesive composition preferably contain no or only a small amount of a component that absorbs light (355 nm).Here, examples of the component that absorbs light (355 nm) include the same components as those in the base material described above.

[0263] <<Method of manufacturing pressure-sensitive adhesive composition>> The pressure-sensitive adhesive compositions such as pressure-sensitive adhesive compositions (I-1) to (I-4) can be obtained by blending the pressure-sensitive adhesive and, if necessary, components other than the pressure-sensitive adhesive, for constituting the pressure-sensitive adhesive composition. The order of addition of the components when blending is not particularly limited, and two or more components may be added simultaneously. The method for mixing the components during blending is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or stirring blades, a method of mixing using a mixer, or a method of mixing by adding ultrasound. The temperature and time for adding and mixing each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. A temperature of 15 to 30°C is preferred.

[0264] ○Middle class The intermediate layer is in the form of a sheet or film and is transparent to light (355 nm).

[0265] In the composite sheet for forming a protective film, the intermediate layer is disposed between the pressure-sensitive adhesive layer and the film for forming a protective film. The type of intermediate layer can be selected arbitrarily depending on the purpose and is not particularly limited.

[0266] The optical properties of the intermediate layer need only satisfy the transmittance condition for the light (355 nm) that the support sheet has described above.

[0267] The intermediate layer can be formed by a known method depending on the type of the intermediate layer. For example, an intermediate layer containing a resin as a main component can be formed by molding a resin composition containing the resin.

[0268] An example of the intermediate layer is a release-improving layer one surface of which is subjected to a release treatment.

[0269] Peelability improvement layer The release property improving layer may be, for example, a multi-layer structure including a resin layer and a release treatment layer formed on the resin layer. In the composite sheet for forming a protective film, the release property improving layer is disposed with the release treatment layer facing the film for forming a protective film.

[0270] Of the peelability improving layers, the resin layer can be prepared by molding a resin composition containing a resin. The release property improving layer can be produced by subjecting one surface of the resin layer to a release treatment.

[0271] The resin layer can be released using various known release agents, such as alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, or wax-based release agents. The release agent is preferably an alkyd-based, silicone-based or fluorine-based release agent in terms of heat resistance.

[0272] The resin constituting the resin layer may be appropriately selected depending on the purpose, and is not particularly limited. Preferred examples of the resin include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyethylene (PE), and polypropylene (PP).

[0273] The resin layer may consist of one layer (single layer) or two or more layers. When it consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0274] The thickness of the peelability improving layer (total thickness of the resin layer and release treatment layer) is preferably 10 to 2000 nm, more preferably 25 to 1500 nm, and particularly preferably 50 to 1200 nm. When the thickness of the peelability improving layer is equal to or greater than the lower limit, the action of the peelability improving layer becomes more pronounced, and further, the effect of suppressing breakage such as cutting of the peelability improving layer becomes higher. When the thickness of the peelability improving layer is equal to or less than the upper limit, semiconductor chips having a protective film or a protective film-forming film, described below, on their back surfaces can be more easily picked up.

[0275] The intermediate layer preferably does not contain or contains only a small amount of a component that absorbs light (355 nm).Here, examples of the component that absorbs light (355 nm) include the same components as those in the base material described above.

[0276] Up to this point, we have mainly explained the case where the support sheet is used in combination with a film for forming a protective film to form a composite sheet for forming a protective film, but the support sheet may also be used in a state where it does not form a composite sheet for forming a protective film, without being used in combination with a film for forming a protective film. For example, after the support sheet is directly attached to a location on the workpiece, laser light with a shorter wavelength than conventional lasers, such as a 355 nm laser, can be irradiated from outside the workpiece through the support sheet onto the location where the support sheet is attached, thereby enabling good printing on the location of the workpiece where the support sheet is attached. This printing can then be clearly seen from outside the workpiece through the support sheet. When printing on any part of the workpiece through a support sheet, the printing can usually be done well, and the printing can be clearly seen, just as when printing on a protective film-forming film or protective film through a support sheet. The support sheet when used without constituting a composite sheet for forming a protective film may be the same as the support sheet when used with constituting a composite sheet for forming a protective film.

[0277] In the composite sheet for forming a protective film of this embodiment, it is preferable that the transmittance of light (355 nm) of the support sheet is equal to or greater than the transmittance of light (355 nm) of the film for forming a protective film ([Transmittance (%) of light (355 nm) of support sheet] ≧ [Transmittance of light (355 nm) of film for forming a protective film]). It is more preferable that the transmittance of light (355 nm) of the support sheet is higher than the transmittance of light (355 nm) of the film for forming a protective film ([Transmittance (%) of light (355 nm) of support sheet] > [Transmittance of light (355 nm) of film for forming a protective film]). A composite sheet for forming a protective film that satisfies these conditions can print well on the film for forming a protective film or a protective film, even when irradiated with laser light having a shorter wavelength than conventional ones (for example, a wavelength of 355 nm), and this printing can be clearly seen through the support sheet, which is an even greater effect.

[0278] In this specification, even after the film for forming a protective film has hardened, as long as the laminated structure of the support sheet and the cured product of the film for forming a protective film (e.g., a protective film) is maintained, this laminated structure is referred to as a "composite sheet for forming a protective film."

[0279] The composite sheet for forming a protective film of this embodiment may also have other layers that do not fall under any of the substrate, adhesive layer, intermediate layer, film for forming a protective film, and release film, as long as the effects of the present invention are not impaired. The type of the other layer is not particularly limited and can be selected arbitrarily depending on the purpose. The position, shape, size, etc. of the other layers can be arbitrarily selected depending on the type of the other layers, and are not particularly limited.

[0280] The thickness of the workpiece to which the composite sheet for forming a protective film of this embodiment is to be attached is not particularly limited, but is preferably 30 to 1000 μm, and more preferably 70 to 400 μm, in order to make it easier to process (e.g., divide) the workpiece into a processed product as described below.

[0281] The composite sheet for forming a protective film of this embodiment is intended to be attached to a workpiece, and a preferred example of the workpiece to be attached to is a semiconductor wafer. The composite sheet for forming a protective film is preferably intended to be attached to the back surface of a semiconductor wafer. It is more preferable that the composite sheet for forming a protective film is to be attached to the back surface of a semiconductor wafer, and that the semiconductor wafer does not have any through-holes between the back surface and the circuit formation surface; it is also possible that the composite sheet for forming a protective film is to be attached to the back surface of a semiconductor wafer, and that the semiconductor wafer does not have any through-holes or cracks between the back surface and the circuit formation surface.

[0282] The target to which the composite sheet for forming a protective film is attached does not include a workpiece after processing. Here, "a workpiece after processing" includes the target workpiece and a workpiece in an incomplete state. Examples of a workpiece in an incomplete state include a workpiece in the middle of processing and a workpiece in which processing has been attempted but the processing has been partially incomplete. Examples of a workpiece in an incomplete state include a semiconductor wafer in which division into semiconductor chips has been attempted but the division has been partially incomplete.

[0283] FIG. 1 is a cross-sectional view schematically illustrating an example of a composite sheet for forming a protective film according to one embodiment of the present invention. The composite sheet 101 for forming a protective film shown here is composed of a support sheet 10 and a film 13 for forming a protective film provided on one side 10a of the support sheet 10 (sometimes referred to as the "first side" in this specification). The support sheet 10 is configured to include a substrate 11 and an adhesive layer 12 provided on one surface 11a of the substrate 11. In the composite sheet 101 for forming a protective film, the adhesive layer 12 is disposed between the substrate 11 and the film 13 for forming a protective film. That is, the composite sheet 101 for forming a protective film is configured by laminating a substrate 11, a pressure-sensitive adhesive layer 12, and a film 13 for forming a protective film in this order in the thickness direction. The surface 10a of the support sheet 10 facing the protective film forming film 13 (sometimes referred to as the "first surface" in this specification) is the same as the surface 12a of the adhesive layer 12 opposite the substrate 11 side (sometimes referred to as the "first surface" in this specification).

[0284] The composite sheet 101 for forming a protective film further includes an adhesive layer 16 for a jig and a release film 15 on the film 13 for forming a protective film. In the composite sheet 101 for forming a protective film, a film 13 for forming a protective film is laminated over the entire or almost entire first surface 12a of the pressure-sensitive adhesive layer 12, and a jig adhesive layer 16 is laminated over a portion of the surface 13a of the film 13 for forming a protective film opposite the pressure-sensitive adhesive layer 12 (sometimes referred to as the "first surface" in this specification), i.e., the area near the periphery. Furthermore, a release film 15 is laminated over the area of ​​the first surface 13a of the film 13 for forming a protective film where the jig adhesive layer 16 is not laminated, and over the surface 16a of the jig adhesive layer 16 opposite the film 13 for forming a protective film (sometimes referred to as the "first surface" in this specification).

[0285] Not only in the case of the composite sheet 101 for forming a protective film, but also in the composite sheet for forming a protective film of this embodiment, the release film (for example, release film 15 shown in Figure 1) has an optional configuration, and the composite sheet for forming a protective film of this embodiment may or may not have a release film.

[0286] In the composite sheet 101 for forming a protective film, a gap may be formed between the release film 15 and the layer that is in direct contact with the release film 15 . For example, although the state in which the release film 15 is in contact (laminated) with the side surface 16c of the jig adhesive layer 16 is shown here, the release film 15 may not be in contact with the side surface 16c. Also, although the state in which the release film 15 is in contact (laminated) with the region of the first surface 13a of the protective film-forming film 13 near the jig adhesive layer 16 is shown here, the release film 15 may not be in contact with the region. Furthermore, the boundary between the first surface 16a and the side surface 16c of the jig adhesive layer 16 may not be clearly distinguishable. The above points also apply to the composite sheets for forming a protective film of other embodiments that include a jig adhesive layer.

[0287] The jig adhesive layer 16 is used to fix the composite sheet for forming a protective film 101 to a jig such as a ring frame. The jig adhesive layer 16 may have, for example, a single-layer structure containing an adhesive component, or a multi-layer structure in which layers containing adhesive components are laminated on both sides of a core sheet.

[0288] In the composite sheet 101 for forming a protective film, the support sheet 10 has a transmittance of 20% or more for light (355 nm), and the film 13 for forming a protective film has a transmittance of 60% or less for light (355 nm).

[0289] The composite sheet 101 for forming a protective film is used by removing the release film 15, attaching any part of the workpiece (not shown) to the first surface 13a of the film 13 for forming a protective film, and then attaching the first surface 16a of the jig adhesive layer 16 to a jig such as a ring frame.

[0290] FIG. 2 is a cross-sectional view schematically showing another example of the composite sheet for forming a protective film according to one embodiment of the present invention. In FIG. 2 and subsequent figures, the same components as those shown in the figures already described are given the same reference numerals as in the figures already described, and detailed description thereof will be omitted.

[0291] The composite sheet 102 for forming a protective film shown here is the same as the composite sheet 101 for forming a protective film shown in Figure 1, except that the shape and size of the film for forming a protective film are different and the adhesive layer for the jig is laminated on the first surface of the pressure-sensitive adhesive layer rather than on the first surface of the film for forming a protective film.

[0292] More specifically, in the composite sheet 102 for forming a protective film, the film 23 for forming a protective film is laminated in a partial region of the first surface 12a of the pressure-sensitive adhesive layer 12, i.e., in a region on the central side in the width direction (left-right direction in FIG. 2) of the pressure-sensitive adhesive layer 12. Furthermore, a jig adhesive layer 16 is laminated in a region of the first surface 12a of the pressure-sensitive adhesive layer 12 where the film 23 for forming a protective film is not laminated, i.e., in a region near the peripheral edge. A release film 15 is laminated on the surface 23a of the film 23 for forming a protective film opposite the pressure-sensitive adhesive layer 12 side (sometimes referred to as the "first surface" in this specification) and on the first surface 16a of the jig adhesive layer 16.

[0293] FIG. 3 is a cross-sectional view schematically showing still another example of the composite sheet for forming a protective film according to one embodiment of the present invention. The composite sheet 103 for forming a protective film shown here is the same as the composite sheet 101 for forming a protective film shown in Figure 1, except that it is configured with a support sheet 20 instead of the support sheet 10, and does not have an adhesive layer 16 for the jig. The support sheet 20 is composed of a base material 11, an adhesive layer 12 provided on a first surface 11a of the base material 11, and an intermediate layer 17 provided on the first surface 12a of the adhesive layer 12. In the composite sheet 103 for forming a protective film, the intermediate layer 17 is disposed between the adhesive layer 12 and the film 23 for forming a protective film. That is, the composite sheet 103 for forming a protective film is configured by laminating the substrate 11, the adhesive layer 12, the intermediate layer 17, and the film 23 for forming a protective film in this order in the thickness direction. The surface 20 a of the support sheet 20 on the protective film-forming film 23 side (sometimes referred to as the “first surface” in this specification) is the same as the first surface 12 a of the pressure-sensitive adhesive layer 12 .

[0294] The area of ​​the surface 17a of the intermediate layer 17 opposite the adhesive layer 12 side (sometimes referred to as the "first surface" in this specification) is smaller than the area of ​​the first surface 12a of the adhesive layer 12 (i.e., the combined area of ​​the area where the protective film forming film 23 is laminated and the area where it is not laminated). The planar shape of the first surface 17a of the intermediate layer 17 is not particularly limited, and may be, for example, a circular shape. The shape and size of the first surface 17a of the intermediate layer 17 may be the same as or different from the shape and size of the first surface 23a of the protective film-forming film 23. However, it is preferable that the entire surface 23b of the protective film-forming film 23 opposite to the first surface 23a (sometimes referred to as the "second surface" in this specification) is covered with the intermediate layer 17.

[0295] FIG. 4 is a cross-sectional view schematically showing still another example of the composite sheet for forming a protective film according to one embodiment of the present invention. The composite sheet 104 for forming a protective film shown here is the same as the composite sheet 101 for forming a protective film shown in FIG. 1, except that it is configured with a support sheet 30 instead of the support sheet 10. The support sheet 30 is made of only the substrate 11 . That is, the composite sheet 104 for forming a protective film is configured by laminating the substrate 11 and the film 13 for forming a protective film in the thickness direction. The surface 30a of the support sheet 30 on the protective film-forming film 13 side (sometimes referred to as the "first surface" in this specification) is the same as the first surface 11a of the base material 11. The substrate 11 has adhesiveness at least on its first surface 11a.

[0296] The composite sheet for forming a protective film of this embodiment is not limited to those shown in Figures 1 to 4, and may be one in which some of the configurations shown in Figures 1 to 4 have been changed or deleted, or one in which other configurations have been added to those described above, within the scope that does not impair the effects of the present invention. More specifically, this is as follows.

[0297] Up to this point, only the composite sheet for forming a protective film 104 shown in Fig. 4 has been shown as a composite sheet for forming a protective film having a support sheet made of a substrate, but an example of a composite sheet for forming a protective film having a support sheet made of a substrate is the composite sheet for forming a protective film 102 shown in Fig. 2 which does not have the adhesive layer 12. However, this is just one example of another composite sheet for forming a protective film having a support sheet made of a substrate.

[0298] Up to this point, only the composite sheet for forming a protective film 103 shown in Fig. 3 has been shown as a composite sheet for forming a protective film that has an intermediate layer as part of the support sheet, but examples of composite sheets for forming a protective film that have an intermediate layer include those shown below. However, these are examples of other composite sheets for forming a protective film that have an intermediate layer. In the composite sheet 101 for forming a protective film shown in FIG. 1, an intermediate layer similar to that shown in FIG. 3 is provided between the adhesive layer 12 and the film 13 for forming a protective film. 2, in which an intermediate layer similar to that shown in FIG. 3 is provided between the adhesive layer 12 and the film 23 for forming a protective film. In the composite sheet 104 for forming a protective film shown in FIG. 4, an intermediate layer similar to that shown in FIG. 3 is provided between the substrate 11 and the film 13 for forming a protective film.

[0299] Up to this point, protective film-forming composite sheets having a jig adhesive layer have been shown as protective film-forming composite sheet 101 shown in Fig. 1, protective film-forming composite sheet 102 shown in Fig. 2, and protective film-forming composite sheet 104 shown in Fig. 4, but examples of protective film-forming composite sheets having a jig adhesive layer include, for example, protective film-forming composite sheet 103 shown in Fig. 3, which has a jig adhesive layer similar to that shown in Fig. 1, etc., in the region of first surface 12a of pressure-sensitive adhesive layer 12 where intermediate layer 17 and protective film-forming film 23 are not laminated. However, this is one example of another protective film-forming composite sheet having a jig adhesive layer.

[0300] A composite sheet for forming a protective film having such a jig adhesive layer is used by attaching the first surface of the jig adhesive layer to a jig such as a ring frame, as in the case of composite sheet for forming a protective film 101 shown in Figure 1. As described above, the composite sheet for forming a protective film of this embodiment may be provided with a jig adhesive layer, regardless of the form of the support sheet and the film for forming a protective film.

[0301] Up to this point, only the composite sheet for forming a protective film 103 shown in Fig. 3 has been shown as a composite sheet for forming a protective film that does not have a jig adhesive layer, but an example of a composite sheet for forming a protective film that does not have a jig adhesive layer is the composite sheet for forming a protective film 102 shown in Fig. 2 that does not have the jig adhesive layer 16. However, this is just one example of another composite sheet for forming a protective film that does not have a jig adhesive layer.

[0302] In Figures 1 to 4, the composite sheet for forming a protective film is shown to consist of a substrate, an adhesive layer, an intermediate layer, a film for forming a protective film, and a release film, but the composite sheet for forming a protective film of this embodiment may also have other layers that do not fall into any of these categories. When the composite sheets for forming a protective film shown in FIGS. 1 to 4 include the other layers, the positions at which they are arranged are not particularly limited.

[0303] In the composite sheet for forming a protective film of this embodiment, the size and shape of each layer can be selected arbitrarily depending on the purpose.

[0304] ◇Manufacturing method of composite sheet for forming protective film The composite sheet for forming a protective film can be produced by laminating the above-mentioned layers in a corresponding positional relationship and adjusting the shapes of some or all of the layers as necessary. The method for forming each layer is as described above.

[0305] For example, when a support sheet is produced by laminating a pressure-sensitive adhesive layer on a substrate, the pressure-sensitive adhesive composition may be applied to the substrate and dried as necessary. Alternatively, a pressure-sensitive adhesive layer can be laminated on a substrate by coating a release film with a pressure-sensitive adhesive composition and optionally drying the composition to form a pressure-sensitive adhesive layer on the release film, and then laminating the exposed surface of the pressure-sensitive adhesive layer to one surface of the substrate. In this case, the pressure-sensitive adhesive composition is preferably coated on the release-treated surface of the release film. Up to this point, the case where a pressure-sensitive adhesive layer is laminated on a substrate has been taken as an example, but the above-mentioned method can also be applied to the case where an intermediate layer or the other layer is laminated on a substrate, for example.

[0306] On the other hand, for example, when a protective film-forming film is to be further laminated on a pressure-sensitive adhesive layer already laminated on a substrate, it is possible to directly form the protective film-forming film by applying a protective film-forming composition to the pressure-sensitive adhesive layer. Layers other than the protective film-forming film can also be laminated on the pressure-sensitive adhesive layer in a similar manner using a composition for forming this layer. In this way, when a new layer (hereinafter abbreviated as "second layer") is formed on any layer (hereinafter abbreviated as "first layer") already laminated on the substrate to form a continuous two-layer laminate structure (in other words, a laminate structure of the first layer and the second layer), a method can be applied in which a composition for forming the second layer is applied to the first layer and dried as necessary. However, it is preferable to form the second layer in advance on a release film using a composition for forming the second layer, and then bond the exposed surface of the second layer opposite the side in contact with the release film to the exposed surface of the first layer to form a continuous two-layer laminate structure. In this case, it is preferable to coat the composition on the release-treated surface of the release film. The release film can be removed as needed after the laminate structure is formed. Here, we have given an example of laminating a film for forming a protective film onto an adhesive layer, but the target laminate structure can be selected arbitrarily, for example, when laminating an intermediate layer or other layer onto an adhesive layer.

[0307] In this way, all layers other than the substrate that make up the composite sheet for forming a protective film can be formed in advance on a release film and then laminated by bonding it to the surface of the desired layer, so the composite sheet for forming a protective film can be manufactured by appropriately selecting the layers that will undergo this process as needed.

[0308] The composite sheet for forming a protective film is usually stored with a release film attached to the surface of the outermost layer (for example, the film for forming a protective film) opposite the support sheet. Therefore, a composition for forming a layer constituting the outermost layer, such as a composition for forming a protective film, is applied to this release film (preferably its release-treated surface) and dried as necessary to form a layer constituting the outermost layer on the release film. The remaining layers are then laminated by any of the methods described above on the exposed surface opposite the side in contact with the release film of this layer, and the composite sheet for forming a protective film with a release film is obtained by leaving the laminated state without removing the release film.

[0309] ◇Manufacturing method for workpieces with protective film (method of using composite sheet for forming protective film) The composite sheet for forming a protective film can be used to manufacture the workpiece with the protective film. As an example of a method for manufacturing a workpiece with a protective film, in which a protective film is provided at any location on the workpiece, the protective film is formed from a film for forming a protective film in the composite sheet for forming a protective film. If the film for forming a protective film is curable, the cured product of the film for forming a protective film is the protective film. If the film for forming a protective film is non-curable, the film for forming a protective film after being attached to any location on the workpiece is the protective film. In a method for manufacturing a workpiece with a protective film, the film for forming a protective film in the composite sheet for forming a protective film is attached to a desired location on the workpiece, thereby providing the composite sheet for forming a protective film on the workpiece (laminating the composite sheet for forming a protective film). and a printing step, after the pasting step, of printing on the protective film-forming film or protective film in the protective film-forming composite sheet in the first laminate by irradiating laser light from outside the support sheet side of the protective film-forming composite sheet through the support sheet, and a processing step, after the printing step, of processing the work to produce a workpiece, and if the protective film-forming film is curable, the method further includes a curing step, after the pasting step, of forming a protective film by curing the protective film-forming film.

[0310] In each step after the pasting step, whether to handle the film for forming a protective film or the protective film is determined by the timing of forming the protective film. When the film for forming a protective film is non-curable, it is the protective film that is handled in each step after the pasting step. When the film for forming a protective film is curable, it is the film for forming a protective film that is handled before the curing step, and it is the protective film that is handled after the curing step. Therefore, in the printing process, printing is performed on the film for forming a protective film in the composite sheet for forming a protective film in the first laminate by irradiating laser light from outside the support sheet side of the composite sheet for forming a protective film through the support sheet, or printing is performed on the protective film in the composite sheet for forming a protective film in the first laminate by irradiating laser light from outside the support sheet side of the composite sheet for forming a protective film through the support sheet.

[0311] An example of a method for manufacturing a workpiece with a protective film, i.e., a semiconductor chip with a protective film, when the work is a semiconductor wafer is a method for manufacturing a semiconductor chip with a protective film, which has a protective film on the back surface of the semiconductor chip, wherein the protective film is formed from a protective film-forming film in the protective film-forming composite sheet, and when the protective film-forming film is curable, a cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film is the protective film after being attached to the back surface of the semiconductor wafer, and the method for manufacturing the semiconductor chip with a protective film includes: to the back surface of the semiconductor wafer to produce a first laminate in which the composite sheet for protective film formation is provided (laminated) on the back surface of the semiconductor wafer; a printing step, after the sticking step, of printing on the film for protective film formation or the protective film in the composite sheet for protective film formation in the first laminate by irradiating laser light from outside the support sheet side of the composite sheet for protective film formation through the support sheet; a dividing step, after the printing step, of dividing the semiconductor wafer to produce semiconductor chips; a cutting step, after the printing step, of cutting the film for protective film formation or the protective film; and a pick-up step of picking up the semiconductor chips equipped with the film for protective film formation or the protective film after the cutting, by separating them from the support sheet. If the film for protective film formation is curable, the method further includes a curing step, after the sticking step, of curing the film for protective film formation to form a protective film.

[0312] In the above manufacturing method, the wavelength of the laser light is preferably shorter than that of conventional laser light, and more preferably 355 nm.

[0313] In the above manufacturing method, when the workpiece is a semiconductor wafer, the workpiece can be the one described above.

[0314] In the manufacturing method, by using the composite sheet for forming a protective film according to the present embodiment, even when irradiated with the laser light having a short wavelength such as 355 nm, it is possible to print satisfactorily on the film for forming a protective film or the protective film in the composite sheet for forming a protective film. Furthermore, this printing can be clearly seen from the outside of the support sheet side of the composite sheet for forming a protective film, through the support sheet.

[0315] The manufacturing method is divided into a manufacturing method that includes the curing step (sometimes referred to as "manufacturing method (1)" in this specification) and a manufacturing method that does not include the curing step (sometimes referred to as "manufacturing method (2)" in this specification). These manufacturing methods will be explained below in order.

[0316] <<Manufacturing method (1)>> The manufacturing method (1) is a method for manufacturing a workpiece with a protective film, which is provided at any location on the workpiece, and the protective film is formed from a protective film-forming film in the protective film-forming composite sheet. Since the protective film-forming film is curable, a cured product of the protective film-forming film is the protective film. In the manufacturing method for the workpiece with a protective film, the protective film-forming film in the protective film-forming composite sheet is attached to a desired location on the workpiece, so that the protective film-forming composite sheet is provided (laminated) on the workpiece. The method includes an attachment step of producing a first laminate, a curing step of forming a protective film by curing the protective film-forming film after the attachment step, a printing step of printing on the protective film-forming film or protective film in the protective film-forming composite sheet in the first laminate by irradiating laser light from outside the support sheet side of the protective film-forming composite sheet through the support sheet after the attachment step, and a processing step of processing the work to produce a workpiece.

[0317] When the workpiece is a semiconductor wafer, the manufacturing method (1) is a method for manufacturing a semiconductor chip with a protective film, which has a protective film on the back surface of the semiconductor chip, and the protective film is formed from a protective film-forming film in the protective film-forming composite sheet, and since the protective film-forming film is curable, a cured product of the protective film-forming film is the protective film, and the manufacturing method for the semiconductor chip with a protective film includes attaching the protective film-forming film in the protective film-forming composite sheet to the back surface of the semiconductor wafer to create a first laminate in which the protective film-forming composite sheet is provided (laminated) on the back surface of the semiconductor wafer. a curing process for forming a protective film by curing the protective film-forming film after the bonding process; a printing process for printing on the protective film-forming film or the protective film in the composite sheet for protective film formation in the first laminate by irradiating laser light from outside the support sheet side of the composite sheet for protective film formation through the support sheet after the bonding process; a dividing process for dividing the semiconductor wafer after the printing process to produce semiconductor chips; a cutting process for cutting the protective film-forming film or the protective film after the printing process; and a picking up process for separating the semiconductor chips having the cut protective film-forming film or the protective film from the support sheet and picking them up.

[0318] When the workpiece is a semiconductor wafer, the order in which the dividing step and the cutting step are performed can be selected arbitrarily depending on the purpose. The dividing step may be performed first, then the cutting step, or the dividing step and the cutting step may be performed simultaneously, or the cutting step may be performed first, then the dividing step. In this embodiment, if the dividing of the semiconductor wafer and the cutting of the protective film forming film or the protective film are performed continuously by the same operation without interruption, regardless of the order, the dividing process and the cutting process are considered to be performed simultaneously.

[0319] The dividing step and the cutting step can both be carried out by known methods depending on the order in which they are carried out.

[0320] When the cutting step is performed after the dividing step, the semiconductor wafer can be divided (in other words, divided into pieces) by, for example, stealth dicing (registered trademark) or laser dicing. Stealth Dicing (registered trademark) is a method as follows. First, a planned dividing point is set within a semiconductor wafer, and a laser beam is irradiated so as to converge at this point, forming a modified layer within the semiconductor wafer. Unlike other parts of the semiconductor wafer, the modified layer of the semiconductor wafer has been altered by the irradiation of the laser beam, and its strength has been weakened. Therefore, when a force is applied to the semiconductor wafer, cracks are generated in the modified layer within the semiconductor wafer, extending in the direction of both sides of the semiconductor wafer, and these cracks become the starting points for dividing (cutting) the semiconductor wafer. Next, a force is applied to the semiconductor wafer to divide the semiconductor wafer at the site of the modified layer, thereby producing semiconductor chips.

[0321] When the cutting step is performed after the dividing step, the protective film or protective film can be cut by, for example, pulling the protective film or protective film in a direction parallel to the surface attached to the semiconductor chip, i.e., by expanding. The expanded protective film or protective film is cut along the periphery of the semiconductor chip. Such cutting by expanding is preferably performed at a low temperature, such as -20 to 5°C.

[0322] When the dividing step and the cutting step are carried out simultaneously, the dividing of the semiconductor wafer and the cutting of the protective film-forming film or the protective film can be carried out simultaneously by dicing such as blade dicing using a blade, laser dicing by irradiating a laser, or water dicing by spraying water containing an abrasive. In addition, by expanding a semiconductor wafer on which a modified layer has been formed by Stealth Dicing (registered trademark) and which has not been divided, together with a protective film forming film or a protective film, in the same manner as described above, it is possible to divide the semiconductor wafer and cut the protective film forming film or the protective film simultaneously.

[0323] When the cutting process is performed before the dividing process, the protective film forming film or the protective film can be cut without dividing the semiconductor wafer by using the same dicing techniques as described above, and the semiconductor wafer can then be divided by breaking.

[0324] 5 is a cross-sectional view for schematically explaining an example of the manufacturing method (1) when the workpiece is a semiconductor wafer. Here, the manufacturing method will be described when the composite sheet for forming a protective film 101 shown in FIG.

[0325] <Attachment process> In the bonding step, the protective film-forming composite sheet 101 from which the release film 15 has been removed is used, and as shown in Fig. 5(a), the protective film-forming film 13 in the protective film-forming composite sheet 101 is bonded to the back surface 9b of the semiconductor wafer 9. This produces a first laminate 901 including the semiconductor wafer 9 and the protective film-forming composite sheet 101 provided on the back surface 9b thereof.

[0326] In the attaching step, the protective film-forming film 13 may be softened by heating and then attached to the semiconductor wafer 9 . It should be noted that bumps and the like on the circuit forming surface 9a of the semiconductor wafer 9 are not shown here. Further, reference numeral 13b indicates the surface (sometimes referred to as "second surface" in this specification) opposite to the first surface 13a of the film 13 for forming a protective film (in other words, the pressure-sensitive adhesive layer 12 side).

[0327] The back surface of the semiconductor wafer 9 may be ground to set the thickness to a desired value, that is, the back surface 9b of the semiconductor wafer 9 may be a ground surface.

[0328] It is preferable that the semiconductor wafer 9 does not have any grooves penetrating between its circuit forming surface 9a and back surface 9b.

[0329] <Curing process> After the attaching step, in the curing step, the protective film-forming film 13 is cured to form a protective film 13', as shown in FIG. 5(b). Here, the case where the curing step is performed before the printing step is shown. In this embodiment, the cured product obtained by curing the protective film-forming film 13 after it has been attached to the semiconductor wafer 9 is used as the protective film, regardless of whether it has been cut or not.

[0330] By carrying out the curing process, the composite sheet 101 for forming a protective film becomes a composite sheet 1011 for forming a protective film in which the film 13 for forming a protective film has become a protective film 13', and a cured first laminate 9011 is obtained which is composed of the semiconductor wafer 9 and the composite sheet 1011 for forming a protective film provided on its back surface 9b. Symbol 13a' indicates the first surface of the protective film 13' corresponding to the first surface 13a of the protective film forming film 13, and symbol 13b' indicates the second surface of the protective film 13' corresponding to the second surface 13b of the protective film forming film 13.

[0331] In the curing step, if the protective film-forming film 13 is thermosetting, the protective film 13' is formed by heating the protective film-forming film 13. If the protective film-forming film 13 is energy ray-curable, the protective film 13' is formed by irradiating the protective film-forming film 13 with energy rays through the support sheet 10.

[0332] In the curing step, the curing conditions of the protective film-forming film 13, that is, the heating temperature and heating time during thermal curing, and the illuminance and light amount of the energy rays during energy ray curing, are as described above.

[0333] <Printing process> 5(c), in the printing step after the bonding step, laser light L is irradiated onto the protective film 13' in the composite sheet 1011 for forming a protective film in the cured first laminate 9011 from the outside of the composite sheet 10 for forming a protective film, through the support sheet 10, to print on the protective film 13'. Printing (not shown) is performed on the second surface 13b' of the protective film 13'.

[0334] By performing the printing process, the composite sheet 1011 for forming a protective film becomes a composite sheet 1012 for forming a protective film having a printed protective film 13', and a printed and cured first laminate 9012 is obtained, which is composed of the semiconductor wafer 9 and the composite sheet 1012 for forming a protective film provided on its back surface 9b.

[0335] The wavelength of the laser light L is preferably shorter than that of conventional laser light, and more preferably 355 nm.

[0336] In the printing process, even when the laser light L having a short wavelength, such as 355 nm, is irradiated, the protective film 13′ in the composite sheet for forming a protective film 1011 can be printed satisfactorily. Furthermore, the printing can be clearly seen from the outside of the composite sheet for forming a protective film 1012 on the support sheet 10 side, through the support sheet 10.

[0337] <Dividing process, cutting process> In this embodiment, after the printing step, a dividing step of dividing the semiconductor wafer 9 to fabricate semiconductor chips and a cutting step of cutting the protective film 13' are performed. As explained above, the order in which the dividing step and the cutting step are performed is not limited. The methods for carrying out the dividing step and cutting step are as described above. 5(d), a plurality of semiconductor chips 91 with protective films are obtained, each of which includes a semiconductor chip 9' and a protective film 130' provided on the back surface 9b' of the semiconductor chip 9' after cutting. All of these plurality of semiconductor chips 91 with protective films are aligned on one support sheet 10, and these semiconductor chips 91 with protective films and the support sheet 10 constitute a group of semiconductor chips 910 with protective films.

[0338] Symbol 130a' indicates the first surface of the protective film 130' after cutting, which corresponds to the first surface 13a' of the protective film 13', and symbol 130b' indicates the second surface of the protective film 130' after cutting, which corresponds to the second surface 13b' of the protective film 13'. Reference numeral 9a' denotes a circuit formation surface of the semiconductor chip 9', which corresponds to the circuit formation surface 9a of the semiconductor wafer 9.

[0339] <Pickup process> After the dividing step and cutting step, in the picking up step, the semiconductor chips 9′ (semiconductor chips 91 with protective films) with the cut protective films 130′ are picked up by being separated from the support sheet 10, as shown in FIG. 5(e). Here, the picking up direction is indicated by arrow I.

[0340] The semiconductor chips 91 with protective films can be picked up by a known method. For example, a vacuum collet or the like can be used as the separating means 8 for separating the semiconductor chips 91 with protective films from the support sheet 10. Note that only the separating means 8 is not shown in cross section here. In this way, the desired semiconductor chip 91 with a protective film is obtained.

[0341] In the semiconductor chips 91 with protective film that were subjected to the printing process, including the picked-up ones, the printing remains clear on the second surface 130b' of the protective film 130' after cutting.

[0342] <Timing for the curing process> So far, the case where the curing step is performed between the adhering step and the printing step has been described, but the timing of performing the curing step is not limited to this in manufacturing method (1). For example, in manufacturing method (1), the curing step may be performed between the printing step and the dividing step, between the printing step and the cutting step, between the dividing step and the cutting step, between the dividing step and the pick-up step, between the cutting step and the pick-up step, or after the pick-up step.

[0343] When the curing step is performed after the bonding step and the printing step, in the printing step, the protective film-forming film 13 in the protective film-forming composite sheet 101 in the first laminate 901 shown in Figure 5(a) is printed on the protective film-forming film 13 by irradiating laser light L from outside the support sheet 10 side of the protective film-forming composite sheet 101 through the support sheet 10. Printing (not shown) is performed on the second surface 13b of the protective film-forming film 13. The printing step in this case can be performed in the same manner as the printing step described above, except that the target of irradiation with the laser light L is the protective film forming film 13, not the protective film 13'.

[0344] In this printing process, even when the laser light L having a short wavelength such as 355 nm is irradiated, the printing can be performed well on the film 13 for forming a protective film in the composite sheet 101 for forming a protective film. Furthermore, the printing can be clearly seen from the outside of the composite sheet 101 for forming a protective film on the support sheet 10 side, through the support sheet 10.

[0345] <Other processes> The manufacturing method (1) may include, in addition to the above-mentioned attaching step, curing step, printing step, dividing step, cutting step, and picking up step, other steps that do not fall into any of these categories. The types of other steps and the timing of performing them can be selected arbitrarily depending on the purpose, and are not particularly limited.

[0346] <<Manufacturing method (2)>> The manufacturing method (2) is a method for manufacturing a workpiece with a protective film, which has a protective film at some location on the workpiece, and the protective film is formed from a protective film forming film in the protective film forming composite sheet.Since the protective film forming film is non-hardening, the protective film forming film after being attached to some location on the workpiece is a protective film.The manufacturing method for the workpiece with a protective film includes: an attachment step of attaching the protective film forming film in the protective film forming composite sheet to a desired location on the workpiece to create a first laminate in which the protective film forming composite sheet is provided (laminated) on the workpiece; a printing step of printing on the protective film in the protective film forming composite sheet in the first laminate by irradiating laser light from outside the support sheet side of the protective film forming composite sheet through the support sheet; and a processing step of processing the workpiece after the printing step to create a workpiece. In the manufacturing method (2), the film for forming a protective film after being attached to the workpiece in the attaching step is a protective film. Manufacturing method (2) is the same as manufacturing method (1) except that, regardless of the type of workpiece, it does not have the curing process and the protective film-forming film after being attached to the workpiece is used as the protective film as is, and it achieves the same effects as manufacturing method (1).

[0347] Up to this point, we have mainly explained the method for manufacturing a workpiece with a protective film when using the composite sheet 101 for forming a protective film shown in Figure 1, but the method for manufacturing a workpiece with a protective film in this embodiment is not limited to this. For example, even if a composite sheet for forming a protective film other than the composite sheet 101 for forming a protective film shown in Figure 1, such as the composite sheets for forming a protective film shown in Figures 2 to 4, is used, a workpiece with a protective film can be manufactured in the same way by the above-mentioned manufacturing method. When using a composite sheet for forming a protective film of another embodiment, based on the structural differences between this sheet and the composite sheet for forming a protective film 101, steps may be added, modified, deleted, etc. as appropriate in the above-mentioned manufacturing method to manufacture a workpiece with a protective film.

[0348] ◇Manufacturing method for workpieces with protective film (method of using protective film forming film) A film for forming a protective film that does not constitute the composite sheet for forming a protective film can also be used to manufacture the workpiece with the protective film. In another example of a method for manufacturing the workpiece with a protective film, the protective film is formed from a film for forming a protective film that does not constitute the composite sheet for forming a protective film, and when the film for forming a protective film is curable, the cured product of the film for forming a protective film is the protective film, and when the film for forming a protective film is non-curable, the film for forming a protective film after being attached to any location on the workpiece is the protective film, and the method for manufacturing the workpiece with a protective film includes attaching the film for forming a protective film to a desired location on the workpiece, thereby forming a second stack on the workpiece on which the film for forming a protective film or the protective film is provided (laminated). An example of a method for manufacturing a workpiece with a protective film includes: an attachment step for producing a layered body; a printing step for printing on the protective film forming film or protective film in the second laminate after the attachment step by directly irradiating laser light onto the protective film forming film or protective film from the outside opposite the work side of the protective film forming film or protective film; and a processing step for processing the workpiece after the printing step to produce a workpiece, and if the protective film forming film is curable, further includes a curing step for forming a protective film by curing the protective film forming film after the attachment step.

[0349] In each step after the pasting step, whether to handle the film for forming a protective film or the protective film is determined by the timing of forming the protective film. When the film for forming a protective film is non-curable, it is the protective film that is handled in each step after the pasting step. When the film for forming a protective film is curable, it is the film for forming a protective film that is handled before the curing step, and it is the protective film that is handled after the curing step. Therefore, in the printing process, printing is performed on the film for forming a protective film in the second laminate by directly irradiating the film for forming a protective film with laser light from the outside, opposite the work side of the film for forming a protective film, or printing is performed on the protective film in the second laminate by directly irradiating the protective film with laser light from the outside, opposite the work side of the protective film.

[0350] Another example of a method for manufacturing a workpiece with a protective film, i.e., a semiconductor chip with a protective film, when the work is a semiconductor wafer is a method for manufacturing a semiconductor chip with a protective film, which has a protective film on the back surface of the semiconductor chip, wherein the protective film is formed from a protective film forming film that does not constitute the protective film forming composite sheet, and when the protective film forming film is curable, a cured product of the protective film forming film is the protective film, and when the protective film forming film is non-curable, the protective film is the protective film after being attached to the back surface of the semiconductor wafer, and the method for manufacturing a semiconductor chip with a protective film includes attaching the protective film forming film to the back surface of the semiconductor wafer, thereby providing the protective film forming film or the protective film on the back surface of the semiconductor wafer. a laminating step of laminating a dicing sheet on the surface of the protective film-forming film or protective film opposite to the semiconductor wafer side of the protective film-forming film or protective film in the second laminate after the laminating step, by directly irradiating the protective film-forming film or protective film with laser light from the outside of the protective film-forming film or protective film opposite to the semiconductor wafer side, or on the surface of the semiconductor wafer opposite to the protective film-forming film side or protective film side of the protective film-forming film; a dividing step of dividing (dicing) the semiconductor wafer after the laminating step to produce semiconductor chips; and a cutting step of cutting the protective film-forming film or protective film after the laminating step. and a pick-up process of separating the protective film-forming film or the semiconductor chip provided with the protective film after cutting from the dicing sheet and picking it up, and if the protective film-forming film is curable, further comprising a curing process of forming a protective film by curing the protective film-forming film after the pasting process.

[0351] The method for manufacturing a workpiece with a protective film when a protective film-forming film that does not constitute a protective film-forming composite sheet is used is the same as the method for manufacturing a workpiece with a protective film when the above-mentioned protective film-forming composite sheet is used, except that such a protective film-forming film is used instead of the protective film-forming composite sheet, and if necessary, other steps different from when a protective film-forming composite sheet is used may be added.

[0352] For example, when manufacturing semiconductor chips with a protective film as workpieces with a protective film, as described above, it is necessary to add the lamination process for laminating the dicing sheet required in the dividing process and cutting process onto a protective film-forming film, a protective film, or a semiconductor wafer.

[0353] In the lamination step, the surface of the protective film-forming film or the protective film, which is the target of lamination of the dicing sheet, is the surface on which printing has been performed in the printing step. In the lamination step, the surface of the semiconductor wafer onto which the dicing sheet is laminated is the circuit formation surface. The dicing sheet may be a known one, and the lamination step may be carried out by a known method. In this embodiment, when a dicing sheet is laminated on the protective film-forming film or the protective film, the laminating step is followed by either the dividing step and the cutting step simultaneously, or the dividing step is performed first, whereas when a dicing sheet is laminated on the semiconductor wafer, the laminating step is followed by either the dividing step and the cutting step simultaneously, or the cutting step is performed first, or the dividing step is performed second.

[0354] In the printing step, the surface to be printed of the film for forming a protective film or the protective film is exposed, and laser light is directly irradiated onto this exposed surface of the film for forming a protective film or the protective film without any intervening means.

[0355] The manufacturing method is divided into a manufacturing method that includes the curing step (sometimes referred to as "manufacturing method (3)" in this specification) and a manufacturing method that does not include the curing step (sometimes referred to as "manufacturing method (4)" in this specification). These manufacturing methods will be explained below in order.

[0356] <<Manufacturing method (3)>> The manufacturing method (3) is a method for manufacturing the workpiece with the protective film, in which the protective film is formed from a protective film-forming film that does not constitute the protective film-forming composite sheet, and since the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and the manufacturing method for the workpiece with the protective film includes: an attachment process for attaching the protective film-forming film to a desired location on the workpiece to create a second laminate in which the protective film-forming film is provided (laminated) on the workpiece; a curing process for forming a protective film by curing the protective film-forming film after the attachment process; a printing process for printing on the protective film-forming film or protective film in the second laminate by directly irradiating laser light from the outside of the protective film-forming film or protective film opposite the work side; and a processing process for processing the workpiece after the printing process to create a workpiece.

[0357] When the workpiece is a semiconductor wafer, the manufacturing method (3) is a method for manufacturing the semiconductor chip with a protective film, in which the protective film is formed from a protective film-forming film that does not constitute the protective film-forming composite sheet, and since the protective film-forming film is curable, a cured product of the protective film-forming film is the protective film, and the manufacturing method of the semiconductor chip with a protective film includes a bonding step of bonding the protective film-forming film to the back surface of the semiconductor wafer to prepare a second laminate in which the protective film-forming film is provided (laminated) on the back surface of the semiconductor wafer, a curing step of forming a protective film by curing the protective film-forming film after the bonding step, and a bonding step of bonding the protective film-forming film to the back surface of the semiconductor wafer. the second laminate, a printing step of printing on the protective film or protective film by directly irradiating laser light from the outside of the protective film or protective film opposite the semiconductor wafer side of the protective film or protective film; the laminating step of laminating a dicing sheet on the surface of the protective film or protective film opposite the semiconductor wafer side of the protective film or protective film after the printing step, or on the surface of the semiconductor wafer opposite the protective film or protective film side of the protective film; the laminating step of dividing (dicing) the semiconductor wafer to produce semiconductor chips after the laminating step; the laminating step of cutting the protective film or protective film; and the picking up step of separating the semiconductor chips equipped with the cut protective film or protective film from the dicing sheet and picking them up.

[0358] <<Manufacturing method (4)>> The manufacturing method (4) is a method for manufacturing the workpiece with a protective film, in which the protective film is formed from a protective film-forming film that does not constitute the protective film-forming composite sheet, and because the protective film-forming film is non-hardening, the protective film-forming film after being attached to a desired location on the workpiece is the protective film. The manufacturing method for the workpiece with a protective film includes: an attaching step of attaching the protective film-forming film to a desired location on the workpiece to create a second laminate in which the protective film is provided (laminated) on the workpiece; a printing step of printing on the protective film in the second laminate by directly irradiating laser light from the outside of the protective film opposite the workpiece side after the attaching step; and a processing step of processing the workpiece after the printing step to create a workpiece. In the manufacturing method (4), the protective film-forming film after being attached to the workpiece in the attaching step is the protective film. Manufacturing method (4) is the same as manufacturing method (3) except that, regardless of the type of workpiece, it does not have the curing process and the protective film-forming film after being attached to the workpiece is used as the protective film as is, and it achieves the same effects as manufacturing method (3).

[0359] ◇Semiconductor device manufacturing method After the protective film-coated workpiece is obtained by the above-described manufacturing method, the protective film-coated workpiece can be used to manufacture a semiconductor device by a known appropriate method depending on the type of workpiece. For example, if the protective film-coated workpiece is a semiconductor chip, the protective film-coated semiconductor chip can be flip-chip bonded to the circuit-forming surface of a substrate, and then formed into a semiconductor package. The semiconductor package can be used to manufacture the desired semiconductor device (not shown). [Example]

[0360] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the examples shown below.

[0361] <Raw materials for resin production> The full names of the raw materials for producing the resins, which are abbreviated in the examples and comparative examples, are shown below. MA: methyl acrylate MMA: methyl methacrylate HEA: 2-hydroxyethyl acrylate 2EHA: 2-ethylhexyl acrylate MOI: 2-methacryloyloxyethyl isocyanate

[0362] <Raw materials for producing the protective film-forming composition> The raw materials used in the production of the protective film-forming composition are shown below. [Polymer component (A)] (A)-1: An acrylic polymer obtained by copolymerizing MA (85 parts by mass) and HEA (15 parts by mass) (weight average molecular weight: 370,000, glass transition temperature: 6°C) (A)-2: An acrylic polymer (weight average molecular weight: 400,000, glass transition temperature: 20°C) obtained by copolymerizing MA (65 parts by mass), MMA (20 parts by mass), and HEA (15 parts by mass). [Thermosetting component (B1)] (B1)-1: Bisphenol A epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 184-194 g / eq) (B1)-2: Bisphenol A epoxy resin ("jER1055" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 800-900 g / eq) (B1)-3: Dicyclopentadiene-type epoxy resin (DIC Corporation "Epicron HP-7200HH", epoxy equivalent 255-260g / eq) (B1)-4: Cresol novolac epoxy resin with acryloyl groups added (Nippon Kayaku Co., Ltd. "CNA-147", epoxy equivalent 518 g / eq) [Thermal hardener (B2)] (B2)-1: Dicyandiamide (ADEKA Corporation "ADEKA Hardener EH-3636AS", heat-activated latent epoxy resin curing agent, active hydrogen content 21 g / eq) [Curing accelerator (C)] (C)-1:2-Phenyl-4,5-dihydroxymethylimidazole ("Curezol 2PHZ" manufactured by Shikoku Chemicals Corporation) [Filling material (D)] (D)-1: Silica filler ("SC2050MA" manufactured by Admatechs Co., Ltd., silica filler surface-modified with an epoxy compound, average particle diameter 0.5 μm) (D)-2: Spherical silica ("YA050C-MJE" manufactured by Admatechs Co., Ltd., average particle size 0.05 μm) [Coupling agent (E)] (E)-1: 3-Aminopropyltrimethoxysilane ("A-1110" manufactured by Nippon Unicar Co., Ltd.) [Colorant (I)] (I)-1: A black pigment prepared by mixing three organic pigments (manufactured by Dainichiseika Chemicals Co., Ltd.)

[0363] [Example 1] <<Support sheet manufacturing>> <Production of adhesive resin (I-2a)> An acrylic polymer having a weight-average molecular weight of 600,000, which is a copolymer of 2EHA (80 parts by mass) and HEA (20 parts by mass), was added with MOI (in an amount such that the total number of moles of isocyanate groups in the MOI was 0.75 times the total number of moles of hydroxyl groups derived from HEA in the acrylic polymer), and an addition reaction was carried out in an air stream at 50°C for 48 hours to obtain the desired adhesive resin (I-2a)-1. Hereinafter, the acrylic polymer may be referred to as "adhesive resin (I-1a)-1."

[0364] <Production of Pressure-Sensitive Adhesive Composition (I-2)> An energy ray-curable adhesive composition (I-2)-1 was prepared containing adhesive resin (I-2a)-1 (100 parts by mass), a hexamethylene diisocyanate crosslinker (Tosoh's "Coronate HL") (4 parts by mass), and a photopolymerization initiator (BASF's "Irgacure 184", 1-hydroxycyclohexyl phenyl ketone) (3 parts by mass), and further containing methyl ethyl ketone as a solvent. The total concentration of all components other than the solvent was 25% by mass. Note that the contents of all components other than methyl ethyl ketone shown here are the contents of the target product excluding the solvent.

[0365] <Manufacture of support sheet> A release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) made of polyethylene terephthalate, one side of which had been treated for release by silicone treatment, was used. The pressure-sensitive adhesive composition (I-2)-1 obtained above was applied to the release-treated surface, and the resulting coating was dried by heating at 100°C for 2 minutes to form a 5 μm-thick energy ray-curable pressure-sensitive adhesive layer. Next, a polypropylene film (1) (thickness 80 μm, colorless) was attached as a substrate to the exposed surface of the adhesive layer to produce a laminated sheet in which the substrate, adhesive layer, and release film were laminated in this order in the thickness direction, i.e., a support sheet with a release film.

[0366] The polypropylene film (1) was subjected to a tensile test in accordance with JIS K 7127 at a tensile speed of 200 mm / min in an environment of 23° C., and the Young's modulus was measured to be 510 MPa.

[0367] <<Manufacturing of protective film formation films>> <Production of protective film-forming composition (III-1)> Polymer component (A)-1 (150 parts by weight), thermosetting components (B1)-1 (60 parts by weight), (B1)-2 (10 parts by weight), (B1)-3 (30 parts by weight), (B2)-1 (2 parts by weight), curing accelerator (C)-1 (2 parts by weight), filler (D)-1 (300 parts by weight), coupling agent (E)-1 (0.5 parts by weight), and colorant (I)-1 (17 parts by weight) were dissolved or dispersed in a mixed solvent of methyl ethyl ketone, toluene, and ethyl acetate, and stirred at 23 ° C. to obtain a thermosetting protective film-forming composition (III-1)-1, with a total concentration of all components other than the solvent being 45% by weight. Note that the amounts of all components other than the mixed solvent shown here are the amounts of the target product, excluding the solvent.

[0368] <Production of protective film> A release film (second release film, "SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) made of polyethylene terephthalate film, one side of which had been treated for release by silicone treatment, was used, and the protective film-forming composition (III-1)-1 obtained above was applied to the release-treated surface, followed by drying at 100°C for 2 minutes to produce a 15 μm thick thermosetting protective film-forming film.

[0369] Furthermore, by bonding the release-treated surface of a release film (first release film, "SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) to the exposed surface of the obtained protective film-forming film that did not have the second release film, a laminated film was obtained that was composed of the protective film-forming film, a first release film provided on one side of the protective film-forming film, and a second release film provided on the other side of the protective film-forming film.

[0370] <<Manufacturing of composite sheets for forming protective films>> The release film was removed from the support sheet obtained above. The first release film was also removed from the laminated film obtained above. The exposed surface of the pressure-sensitive adhesive layer obtained by removing the release film was then bonded to the exposed surface of the film for forming a protective film obtained by removing the first release film, thereby producing a composite sheet for forming a protective film, which was configured by laminating the substrate, pressure-sensitive adhesive layer, film for forming a protective film, and second release film in this order in the thickness direction.

[0371] <<Evaluation of the support sheet>> <Measurement of light (355 nm) transmittance of support sheet> The release film was removed from the support sheet obtained above. The transmittance of light in the wavelength range of 190 to 1200 nm was measured for this support sheet using a spectrophotometer (Shimadzu Corporation's UV-Vis-NIR Spectrophotometer UV-3600). The large sample chamber attached to the spectrophotometer, MPC-3100, and the integrating sphere built into the spectrophotometer were used. The transmittance of light (355 nm) was calculated from the measurement results. The results are shown in Table 1.

[0372] <Measurement of transmittance of light (355 nm) through the substrate> The transmittance of light (355 nm) of the polypropylene film (1) used in the production of the support sheet was calculated in the same manner as in the case of the support sheet. The results are shown in Table 1.

[0373] <<Evaluation of protective film formation films>> <Measurement of light (355 nm) transmittance> The first release film and the second release film were removed from the laminated film obtained above, and the light transmittance (355 nm) of the obtained film for forming a protective film was measured in the same manner as in the case of the support sheet described above. The results are shown in Table 1.

[0374] <<Evaluation of composite sheets for forming protective films>> <Evaluation of printability and print visibility> The second release film was removed from the composite sheet for forming a protective film obtained above, and the exposed surface of the film for forming a protective film was attached to the polished surface corresponding to the back surface of an 8-inch silicon wafer (thickness 350 μm), thereby obtaining a first laminate composed of the composite sheet for forming a protective film and the silicon wafer laminated together. Next, this first laminate was heat-treated in an oven at 130° C. for 2 hours to thermally cure the film for forming a protective film, thereby forming a protective film. Next, the protective film in the cured first laminate obtained by this thermal curing was printed on the protective film by irradiating it with laser light from the outside of the support sheet side of the composite sheet for forming a protective film, through the support sheet. At this time, the laser light wavelength was 355 nm, the laser light frequency was 40 kHz, the laser light output was 0.30 W, and the size of each character was 1 cm long and 0.8 cm wide, printing the four alphabetical characters "ABCD."

[0375] Next, in the printed and cured first laminate obtained by this printing, the substrate and adhesive layer (i.e., the support sheet) were removed from the printed protective film, and five evaluators directly visually observed the printed surface of the protective film. Then, the printability and print visibility of the composite sheet for forming a protective film were evaluated according to the following criteria. The results are shown in Table 1. (Evaluation criteria) A: All five evaluators judged that the printing was easily visible. B: One to four evaluators judged the printing to be easily visible, and all remaining evaluators judged the printing to be visible, although inferior to "A". C: All five evaluators judged the print to be inferior to "A" but still visible. D: One or more evaluators judged the printing to be invisible.

[0376] <<Evaluation of protective film formation films>> <Evaluation of printability and print visibility> The first release film was removed from the laminated film obtained above, and the exposed surface of the protective film-forming film thus obtained was attached to the polished surface corresponding to the back surface of the same 8-inch silicon wafer as above.Furthermore, the second release film was removed from the attached protective film-forming film, thereby obtaining a second laminate composed of the protective film-forming film and the silicon wafer laminated together. Next, this second laminate was heat-treated in an oven at 130° C. for 2 hours to thermally cure the film for forming a protective film, thereby forming a protective film. Next, the protective film in the heat-cured second laminate was directly irradiated with laser light from the side opposite the silicon wafer side of the protective film, under the same laser light irradiation conditions as in the case of using the composite sheet for forming a protective film described above.

[0377] Next, five evaluators directly visually observed the printed surface of the protective film from the outside of the printed second laminate on the protective film side. The printability and print visibility of the protective film-forming film were evaluated according to the same criteria as above. The results are shown in Table 1.

[0378] <<Production and evaluation of support sheets, films for forming protective films, and composite sheets for forming protective films>> [Example 2] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 1, except that when manufacturing the support sheet, a polypropylene film (2) (thickness 80 μm, colorless, Young's modulus 510 MPa) of a different type was used as the base material instead of the polypropylene film (1) (thickness 80 μm, colorless). The Young's modulus of the polypropylene film (2) was measured in the same manner as in Example 1, and was found to be 340 MPa. The results are shown in Table 1.

[0379] [Example 3] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were produced and evaluated in the same manner as in Example 2, except that a non-energy ray-curable pressure-sensitive adhesive composition (I-4)-1 produced by the method described below was used instead of the energy ray-curable pressure-sensitive adhesive composition (I-2)-1 when producing the support sheet. The thickness of the pressure-sensitive adhesive layer was also 5 μm, the same as in Example 2. The results are shown in Table 1.

[0380] <Production of Pressure-Sensitive Adhesive Composition (I-4)> A non-energy ray curable adhesive composition (I-4)-1 was prepared containing an adhesive resin (I-1a)-1 (100 parts by mass), a hexamethylene diisocyanate crosslinker ("Coronate HL" manufactured by Tosoh Corporation) (5 parts by mass), and methyl ethyl ketone as a solvent, with the total concentration of all components other than the solvent being 25% by mass. Note that the contents of all components other than methyl ethyl ketone shown here are the contents of the target product excluding the solvent.

[0381] [Example 4] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were produced and evaluated in the same manner as in Example 3, except that the non-energy ray-curable pressure-sensitive adhesive composition (I-4)-2 produced by the method described below was used instead of the non-energy ray-curable pressure-sensitive adhesive composition (I-4)-1 when producing the support sheet. The thickness of the pressure-sensitive adhesive layer was also 5 μm, the same as in Example 3. The results are shown in Table 1.

[0382] <Production of Pressure-Sensitive Adhesive Composition (I-4)> A non-energy ray curable pressure-sensitive adhesive composition (I-4)-2 was prepared containing the pressure-sensitive adhesive resin (I-1a)-1 (100 parts by mass) and a trifunctional xylylene diisocyanate crosslinker ("Takenate-D110N" manufactured by Mitsui Takeda Chemicals Inc.) (7 parts by mass), and further containing methyl ethyl ketone as a solvent, with the total concentration of all components other than the solvent being 25% by mass. Note that the contents of all components other than methyl ethyl ketone shown here are the contents of the target product excluding the solvent.

[0383] [Example 5] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were produced and evaluated in the same manner as in Example 1, except that a non-energy ray-curable pressure-sensitive adhesive composition (I-4)-3 produced by the method described below was used instead of the energy ray-curable pressure-sensitive adhesive composition (I-2)-1 when producing the support sheet. The thickness of the pressure-sensitive adhesive layer was also 5 μm, the same as in Example 1. The results are shown in Table 1.

[0384] <Production of Pressure-Sensitive Adhesive Composition (I-4)> A non-energy ray curable adhesive composition (I-4)-3 was prepared containing adhesive resin (I-1a)-2 (100 parts by mass), a trifunctional xylylene diisocyanate crosslinker ("Takenate-D110N" manufactured by Mitsui Takeda Chemicals Inc.) (18 parts by mass), and methyl ethyl ketone as a solvent, with the total concentration of all components other than the solvent being 25% by mass. Note that the contents of all components other than methyl ethyl ketone shown here are the contents of the target product excluding the solvent. The adhesive resin (I-1a)-2 is an acrylic polymer having a weight-average molecular weight of 400,000, which is obtained by copolymerizing 2EHA (70 parts by mass), MMA (20 parts by mass), and HEA (10 parts by mass).

[0385] [Example 6] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 3, except that when manufacturing the support sheet, a polypropylene film (3) (thickness 80 μm, blue) of a different type was used as the base material instead of the polypropylene film (2) (thickness 80 μm, colorless, Young's modulus 510 MPa). The Young's modulus of the polypropylene film (3) was measured in the same manner as in Example 1, and was found to be 280 MPa. The results are shown in Table 1.

[0386] [Example 7] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 5, except that when manufacturing the support sheet, a polypropylene film (2) (thickness 80 μm, colorless, Young's modulus 340 MPa) was used as the base material instead of a polypropylene film (1) (thickness 80 μm, colorless, Young's modulus 510 MPa). The results are shown in Table 1.

[0387] [Example 8] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 5, except that when manufacturing the support sheet, a polypropylene film (3) (thickness 80 μm, blue, Young's modulus 280 MPa) was used as the base material instead of a polypropylene film (1) (thickness 80 μm, colorless, Young's modulus 510 MPa). The results are shown in Table 1.

[0388] [Example 9] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 3, except that when manufacturing the support sheet, a polypropylene film (1) (thickness 80 μm, colorless, Young's modulus 510 MPa) was used as the base material instead of a polypropylene film (2) (thickness 80 μm, colorless, Young's modulus 340 MPa). The results are shown in Table 1.

[0389] [Example 10] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 4, except that when manufacturing the support sheet, a polypropylene film (1) (thickness 80 μm, colorless, Young's modulus 510 MPa) was used as the base material instead of a polypropylene film (2) (thickness 80 μm, colorless, Young's modulus 340 MPa). The results are shown in Table 1.

[0390] [Example 11] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were produced and evaluated in the same manner as in Example 9, except that the thermosetting composition for forming a protective film (III-1)-1 was replaced with the thermosetting composition for forming a protective film (III-1)-2 produced by the method described below when producing the film for forming a protective film. The thickness of the film for forming a protective film was also 15 μm, the same as in Example 9. The results are shown in Table 1.

[0391] <Production of protective film-forming composition (III-1)> Polymer component (A)-1 (150 parts by weight), thermosetting components (B1)-1 (60 parts by weight), (B1)-2 (10 parts by weight), (B1)-3 (30 parts by weight), (B2)-1 (2 parts by weight), curing accelerator (C)-1 (2 parts by weight), filler (D)-1 (300 parts by weight), coupling agent (E)-1 (0.5 parts by weight), and colorant (I)-1 (4 parts by weight) were dissolved or dispersed in a mixed solvent of methyl ethyl ketone, toluene, and ethyl acetate, and stirred at 23 ° C. to obtain a thermosetting protective film-forming composition (III-1)-2 having a total concentration of all components other than the solvent of 45% by weight. Note that the amounts of all components other than the mixed solvent shown here are the amounts of the target product excluding the solvent.

[0392] [Reference example 1] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were produced and evaluated in the same manner as in Example 9, except that a thermosetting composition for forming a protective film (III-1)-3 produced by the method described below was used instead of the thermosetting composition for forming a protective film (III-1)-1 when producing the film for forming a protective film. The thickness of the film for forming a protective film was also 15 μm, the same as in Example 9. The results are shown in Table 1.

[0393] <Production of protective film-forming composition (III-1)> Polymer component (A)-1 (150 parts by weight), thermosetting components (B1)-1 (60 parts by weight), (B1)-2 (10 parts by weight), (B1)-3 (30 parts by weight), (B2)-1 (2 parts by weight), curing accelerator (C)-1 (2 parts by weight), filler (D)-1 (300 parts by weight), coupling agent (E)-1 (0.5 parts by weight), and colorant (I)-1 (1 part by weight) were dissolved or dispersed in a mixed solvent of methyl ethyl ketone, toluene, and ethyl acetate, and stirred at 23 ° C. to obtain a thermosetting protective film-forming composition (III-1)-3 having a total concentration of all components other than the solvent of 45% by weight. Note that the amounts of all components other than the mixed solvent shown here are the amounts of the target product excluding the solvent.

[0394] [Example 12] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were produced and evaluated in the same manner as in Example 9, except that a thermosetting composition for forming a protective film (III-1)-4 produced by the method described below was used instead of the thermosetting composition for forming a protective film (III-1)-1 when producing the film for forming a protective film. The thickness of the film for forming a protective film was also 15 μm, the same as in Example 9. The results are shown in Table 1.

[0395] <Production of protective film-forming composition (III-1)> Polymer component (A)-1 (150 parts by weight), thermosetting components (B1)-1 (60 parts by weight), (B1)-2 (10 parts by weight), (B1)-3 (30 parts by weight), (B2)-1 (2 parts by weight), curing accelerator (C)-1 (2 parts by weight), filler (D)-1 (300 parts by weight), coupling agent (E)-1 (0.5 parts by weight), and colorant (I)-1 (30 parts by weight) were dissolved or dispersed in a mixed solvent of methyl ethyl ketone, toluene, and ethyl acetate, and stirred at 23 ° C. to obtain a thermosetting protective film-forming composition (III-1)-4, with a total concentration of all components other than the solvent being 45% by weight. Note that the amounts of all components other than the mixed solvent shown here are the amounts of the target product, excluding the solvent.

[0396] [Example 13] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 6, except that a polyethylene terephthalate film (1) (thickness 50 μm, colorless) was used as the base material instead of a polypropylene film (3) (thickness 80 μm, blue, Young's modulus 280 MPa) when manufacturing the support sheet. The Young's modulus of the polyethylene terephthalate film (1) was measured in the same manner as in Example 1, and was found to be 5000 MPa. The results are shown in Table 1.

[0397] [Example 14] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 12, except that a polyvinyl chloride film (1) (thickness 70 μm, black) was used as the base material instead of a polypropylene film (1) (thickness 80 μm, colorless, Young's modulus 510 MPa) when manufacturing the support sheet. The Young's modulus of the polyvinyl chloride film (1) was measured in the same manner as in Example 1, and was found to be 400 MPa. The results are shown in Table 1.

[0398] [Example 15] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 6, except that, when manufacturing the support sheet, a non-energy ray-curable adhesive composition (I-4)-4 manufactured by the method described below was used instead of the non-energy ray-curable adhesive composition (I-4)-1, and the thickness of the adhesive layer was changed to 10 μm instead of 5 μm. The results are shown in Table 1.

[0399] <Production of Pressure-Sensitive Adhesive Composition (I-4)> A non-energy ray curable pressure-sensitive adhesive composition (I-4)-4 was prepared containing the pressure-sensitive adhesive resin (I-1a)-2 (100 parts by mass), a trifunctional xylylene diisocyanate crosslinker ("Takenate-D110N" manufactured by Mitsui Takeda Chemicals Inc.) (15 parts by mass), and methyl ethyl ketone as a solvent, with the total concentration of all components other than the solvent being 25% by mass. Note that the contents of all components other than methyl ethyl ketone shown here are the contents of the target product excluding the solvent.

[0400] [Example 16] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 1, except that, when manufacturing the support sheet, energy ray-curable adhesive composition (I-2)-2 manufactured by the method described below was used instead of energy ray-curable adhesive composition (I-2)-1, and the thickness of the adhesive layer was changed to 10 μm instead of 5 μm. The results are shown in Table 1.

[0401] <Production of Pressure-Sensitive Adhesive Composition (I-2)> The adhesive resin (I-2a)-1 (100 parts by mass), a trifunctional xylylene diisocyanate crosslinker (Mitsui Takeda Chemicals' "Takenate-D110N") (7 parts by mass), and a photopolymerization initiator (BASF's "Irgacure 127", 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one) (3 parts by mass), and further containing methyl ethyl ketone as a solvent, were used to prepare an energy ray-curable adhesive composition (I-2)-2, in which the total concentration of all components other than the solvent was 25% by mass. Note that the contents of all components other than methyl ethyl ketone shown here are the contents of the target product excluding the solvent.

[0402] [Example 17] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 2, except that when manufacturing the support sheet, the energy ray-curable adhesive composition (I-2)-2 was used instead of the energy ray-curable adhesive composition (I-2)-1, and the thickness of the adhesive layer was changed from 5 μm to 10 μm. The results are shown in Table 1.

[0403] [Example 18] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 3, except that when manufacturing the support sheet, the polyvinyl chloride film (1) (thickness 70 μm, black, Young's modulus 400 MPa) was used as the base material instead of the polypropylene film (2) (thickness 80 μm, colorless, Young's modulus 340 MPa). The results are shown in Table 1.

[0404] [Comparative Example 1] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were manufactured and evaluated in the same manner as in Example 3, except that a polyvinyl chloride film (2) (thickness 70 μm, black) was used as the base material instead of a polypropylene film (2) (thickness 80 μm, colorless, Young's modulus 340 MPa) when manufacturing the support sheet. The Young's modulus of the polyvinyl chloride film (2) was measured in the same manner as in Example 1, and was found to be 350 MPa. The results are shown in Table 1.

[0405] [Example 19] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were produced and evaluated in the same manner as in Example 1, except that a thermosetting composition for forming a protective film (III-1)-5 produced by the method described below was used instead of the thermosetting composition for forming a protective film (III-1)-1 when producing the film for forming a protective film. The thickness of the film for forming a protective film was also 15 μm, the same as in Example 1. The results are shown in Table 1.

[0406] <Production of protective film-forming composition (III-1)> Polymer component (A)-2 (150 parts by mass), thermosetting component (B1)-4 (10 parts by mass), (B2)-1 (0.2 parts by mass), filler (D)-2 (100 parts by mass), and colorant (I)-1 (2 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain a thermosetting protective film-forming composition (III-1)-5, with a total concentration of all components other than the solvent of 45% by mass. Note that the amounts of all components other than methyl ethyl ketone shown here are the contents of the target product excluding the solvent.

[0407] [Reference example 2] A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were produced and evaluated in the same manner as in Example 1, except that a thermosetting composition for forming a protective film (III-1)-6 produced by the method described below was used instead of the thermosetting composition for forming a protective film (III-1)-1 when producing the film for forming a protective film. The thickness of the film for forming a protective film was also 15 μm, the same as in Example 1. The results are shown in Table 1.

[0408] <Production of protective film-forming composition (III-1)> Polymer component (A)-2 (150 parts by mass), thermosetting component (B1)-4 (10 parts by mass), (B2)-1 (0.2 parts by mass), filler (D)-2 (100 parts by mass), and colorant (I)-1 (0.7 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain a thermosetting protective film-forming composition (III-1)-6, with a total concentration of all components other than the solvent being 45% by mass. Note that the amounts of all components other than methyl ethyl ketone shown here are the amounts of the target product excluding the solvent.

[0409] Comparative Example 2 A support sheet, a film for forming a protective film, and a composite sheet for forming a protective film were produced and evaluated in the same manner as in Example 1, except that a thermosetting composition for forming a protective film (R1) produced by the method described below was used instead of the thermosetting composition for forming a protective film (III-1)-1 when producing the film for forming a protective film. The thickness of the film for forming a protective film was also 15 μm, the same as in Example 1. The results are shown in Table 1.

[0410] <Production of protective film-forming composition (R1)> Polymer component (A)-2 (150 parts by mass), thermosetting component (B1)-4 (10 parts by mass), (B2)-1 (0.2 parts by mass), filler (D)-2 (100 parts by mass), and colorant (I)-1 (0.5 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain a thermosetting protective film-forming composition (R1) with a total concentration of all components other than the solvent of 45% by mass. Note that the amounts of all components other than methyl ethyl ketone shown here are the amounts of the target product excluding the solvent.

[0411] [Table 1]

[0412] [Table 2]

[0413] [Table 3]

[0414] [Table 4]

[0415] As is clear from the above results, in Examples 1 to 19, the printability and print visibility of the composite sheets for forming a protective film were good even when irradiated with laser light of a shorter wavelength than conventional ones. In Examples 1 to 19, the transmittance of the support sheet for light (355 nm) was 25% or more (25 to 91%), and the transmittance of the support sheet for light (355 nm) was high, while the transmittance of the film for forming a protective film for light (355 nm) was 59% or less (18 to 59%), and the film for forming a protective film had high absorbency of light (355 nm).

[0416] In all of Examples 1 to 17 and 19, the transmittance of light (355 nm) through the support sheet was higher than the transmittance of light (355 nm) through the film for forming a protective film.

[0417] Focusing on the substrate alone, in Examples 1 to 19, the transmittance of light (355 nm) was 26% or more (26 to 93%), and the transmittance of light (355 nm) alone was high. Therefore, in terms of optical properties, these substrates were also suitable as support sheets made of substrates.

[0418] Focusing on the single protective film-forming film, Examples 1 to 19 had good printability and print visibility.

[0419] The protective film-forming film and the protective film exhibit roughly the same transmittance for light of the same wavelength. Therefore, the composite sheets for protective film-forming of Examples 1 to 19 were judged to have good printability and print visibility even when irradiated with laser light of a shorter wavelength than conventional films, whether the protective film-forming film was not cured or cured, as in the above-mentioned case where the film was cured.

[0420] In Reference Examples 1 and 2 and Comparative Example 2, the printability and print visibility of the composite sheet for forming a protective film were poor when irradiated with laser light having a shorter wavelength than conventional ones. In Reference Examples 1 and 2 and Comparative Example 2, the transmittance of the film for forming a protective film for light (355 nm) was 62% or more (62 to 89%), and the transmittance of the film for forming a protective film for light (355 nm) was high. Therefore, in Reference Examples 1 and 2 and Comparative Example 2, although the transmittance of the support sheet for light (355 nm) was 89% or more (89 to 91%), and the transmittance of the support sheet for light (355 nm) was high, much of the laser light passed through the protective film, and the printability was poor.

[0421] In Comparative Example 1, the printability and print visibility of the composite sheet for forming a protective film were also poor when irradiated with laser light having a shorter wavelength than conventional ones.

[0422] In Comparative Example 1, the transmittance of the film for forming a protective film at light (355 nm) was 30%, and this film for forming a protective film had high light (355 nm) absorption and corresponded to the film for forming a protective film according to one embodiment of the present invention described above. However, in Comparative Example 1, the transmittance of the support sheet at light (355 nm) was 4%, and the support sheet had low transmittance at light (355 nm). Therefore, in Comparative Example 1, the laser light did not sufficiently reach the protective film through the support sheet, and printability was poor.

[0423] From the results of the above-mentioned Examples, Reference Examples and Comparative Examples, it was confirmed that the transmittance of light (355 nm) of the support sheet tends to be higher as the coloring degree of the support sheet (substrate, adhesive layer, etc.) is lower, the transmittance tends to be higher as the content of components having aromatic cyclic groups such as benzene ring skeletons in the support sheet (substrate, adhesive layer, etc.) is lower, and the transmittance tends to be higher as the thickness of the support sheet (substrate, adhesive layer, etc.) is thinner. [Industrial Applicability]

[0424] The present invention can be used in the manufacture of semiconductor devices. [Explanation of symbols]

[0425] 101, 102, 103, 104... Composite sheet for forming a protective film, 1011... Composite sheet for forming a protective film in which a film for forming a protective film has become a protective film, 1012... Composite sheet for forming a protective film with a printed protective film, 10, 20, 30... Support sheet, 10a, 20a, 30a... One side (first side) of the support sheet, 13, 23... Film for forming a protective film, 13'... Protective film, 130'... Protective film after cutting, 9... Semiconductor wafer, 9a... Circuit formation side of semiconductor wafer, 9b... Back side of semiconductor wafer, 9'... Semiconductor chip, 91... Semiconductor chip with protective film, 901... First laminate, 9011... Cured first laminate, 9012... Printed and cured first laminate, L... Laser light

Claims

1. A protective film-forming film having a transmittance of 35% or less for light having a wavelength of 355 nm and intended for printing with a laser beam having a wavelength shorter than 532 nm, the film for forming a protective film is a thermosetting film for forming a protective film, containing a polymer component (A), an epoxy resin (B1), a thermosetting agent (B2), a filler (D), and a colorant (I), In the film for forming a protective film, the total content of the epoxy resin (B1) and the thermosetting agent (B2) is 50 to 75 parts by mass with respect to 100 parts by mass of the content of the polymer component (A), In the film for forming a protective film, the content ratio of the filler (D) to the total mass of the film for forming a protective film is 30 to 55 mass%, In the film for forming a protective film, the content ratio of the colorant (I) to the total mass of the film for forming a protective film is 0.05 to 12 mass % (however, excluding films for forming a protective film containing an ultraviolet-curable component).

2. A support sheet and a protective film-forming film provided on one surface of the support sheet, The support sheet has a transmittance of 20% or more for light having a wavelength of 355 nm, A composite sheet for forming a protective film, wherein the film for forming a protective film is the film for forming a protective film according to claim 1 .

3. The composite sheet for forming a protective film according to claim 2, wherein the transmittance of the support sheet for light having a wavelength of 355 nm is equal to or greater than the transmittance of the film for forming a protective film for light having a wavelength of 355 nm.

4. the composite sheet for forming a protective film is to be attached to the back surface of a semiconductor wafer, 4. The composite sheet for forming a protective film according to claim 2, wherein the semiconductor wafer has no grooves penetrating between the back surface and the circuit-forming surface opposite to the back surface.

5. The composite sheet for forming a protective film is for forming a protective film on any part of a workpiece obtained by processing a workpiece, The protective film forming film is intended to be attached to any location on a workpiece, the thermosetting product of the protective film-forming film is the protective film, A composite sheet for forming a protective film according to any one of claims 2 to 4, wherein the film for forming a protective film in the composite sheet for forming a protective film is attached to any location on the workpiece, and then the film for forming a protective film or the protective film in the composite sheet for forming a protective film is printed on the film for forming a protective film or the protective film by irradiating laser light from outside the support sheet side of the composite sheet for forming a protective film through the support sheet.

6. A method for manufacturing a workpiece with a protective film, The workpiece with a protective film includes a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, The protective film is formed from a film for forming a protective film in the composite sheet for forming a protective film according to any one of claims 2 to 5, the thermosetting product of the protective film-forming film is the protective film, The method for manufacturing the workpiece with the protective film includes a pasting step of pasting a film for forming a protective film in the composite sheet for forming a protective film to a desired location on the workpiece, thereby producing a first laminate in which the composite sheet for forming a protective film is provided on the workpiece; a curing step of thermally curing the protective film-forming film after the attaching step to form the protective film; a printing step of printing on the film for forming a protective film or the protective film in the composite sheet for forming a protective film in the first laminate after the attaching step by irradiating the film for forming a protective film or the protective film with laser light having a wavelength of 355 nm from the outside of the support sheet side of the composite sheet for forming a protective film through the support sheet; A method for manufacturing a workpiece with a protective film, comprising: a processing step of processing the workpiece to produce a workpiece after the printing step.

7. A method for manufacturing a workpiece with a protective film, The workpiece with a protective film includes a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, The protective film is formed from the film for forming a protective film according to claim 1, the thermosetting product of the protective film-forming film is the protective film, The method for manufacturing the workpiece with a protective film includes a pasting step of pasting the protective film forming film on a desired location of the workpiece to produce a second laminate in which the protective film forming film is provided on the workpiece; a curing step of thermally curing the protective film-forming film after the attaching step to form the protective film; After the attaching step, a printing step of printing on the protective film-forming film or the protective film in the second laminate by directly irradiating the protective film-forming film or the protective film with laser light having a wavelength of 355 nm from the outside of the protective film-forming film or the protective film opposite to the work side; A method for manufacturing a workpiece with a protective film, comprising: a processing step of processing the workpiece to produce a workpiece after the printing step.

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