Film for protective film formation, composite sheet for protective film formation, and method for manufacturing workpiece processed product with protective film

Abstract

Provided is a composite sheet for protective film formation, which includes a support sheet having a transmittance of 20% or more for light having a wavelength of 355 nm and a protective film formation film provided on one surface of the support sheet, the protective film formation film having a transmittance of 60% or less for light having a wavelength of 355 nm.

Description

Technical Field

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

[0002] This application claims priority based on Japanese Special Purpose Application 2019-162135 filed in Japan on September 5, 2019, the contents of which are incorporated herein by reference. Background Technology

[0003] In the manufacturing process of semiconductor devices, protective films are sometimes used to protect the workpieces that need to be processed in order to obtain the target object.

[0004] For example, in the manufacture of semiconductor devices using a mounting method known as face-down, a semiconductor wafer with electrodes such as bumps on its circuit-forming surface is used as a workpiece. To suppress crack formation in the semiconductor wafer or semiconductor chip, which is a cleavage of the wafer, a protective film is sometimes used to protect the back side of the semiconductor wafer or chip opposite to the circuit-forming surface. Furthermore, in the manufacturing process of semiconductor devices, a semiconductor device panel, as described later, is used as a workpiece. To suppress warping or cracking on this panel, a protective film is sometimes used to protect any part of the panel.

[0005] To form the aforementioned protective film, for example, a protective film forming composite sheet is used, which is composed of a support sheet, and further wherein a protective film forming film for forming the protective film is provided on one side of the support sheet.

[0006] The protective film for forming can function as a protective film either by curing or in an uncured state. Furthermore, a support sheet can be used to fix a workpiece having the protective film for forming or the protective film itself. For example, when using a semiconductor wafer as a workpiece, the support sheet can be used as a dicing sheet necessary for dividing the semiconductor wafer into semiconductor chips. Examples of support sheets include those having a substrate and an adhesive layer disposed on one side of the substrate, and support sheets made of a substrate. When the support sheet has an adhesive layer, in a composite sheet for forming a protective film, the adhesive layer is disposed between the substrate and the protective film for forming.

[0007] When using the above-mentioned protective film forming composite sheet, first attach the protective film forming film from the protective film forming composite sheet to the target position of the workpiece.

[0008] Then, as needed, the workpiece having the aforementioned protective film forming composite sheet is processed to obtain a workpiece. Then, sometimes at any stage before obtaining the target semiconductor device, laser irradiation is used to imprint (laser marking) the protective film forming film or the side of the protective film opposite to the side attached to the workpiece or workpiece (i.e., the support sheet side of the protective film forming composite sheet). This marking can, for example, be used for identification of the workpiece or workpiece having the protective film. Since the marking applied to the protective film forming film maintains the same state even after the protective film is formed by curing the film, laser marking can be performed at any stage of the protective film forming film and the protective film.

[0009] For example, when laser printing is performed on a laminate having a structure in which a support sheet, a protective film forming film or a protective film, and a workpiece or a workpiece being stacked sequentially along their thickness direction, the protective film forming film or the protective film is irradiated with laser light from the outside of the support sheet side of the laminate, with the support sheet in between; or, the protective film forming film or the protective film is irradiated with laser light from the outside of the workpiece or workpiece side of the laminate, with the workpiece or the workpiece being in between.

[0010] When irradiating a laser through a support sheet, the following technical problems sometimes arise. Specifically, the support sheet must allow the laser to pass through at a certain level, but the support sheet typically contains light-absorbing components. Such components are particularly common in curable adhesive layers. Therefore, the composition of the support sheet needs to be adjusted to avoid excessively hindering laser transmission.

[0011] On the other hand, the wavelength of the laser used for irradiation at this time only needs to be suitable for printing. To date, lasers with wavelengths of 532 nm or 1064 nm, for example, for which the generation method has been established, have been widely used. However, it has been found that printing accuracy can be improved when using lasers with shorter wavelengths, and the usefulness will be greater if lasers with shorter wavelengths than before can be used.

[0012] As a support sheet with a transmittance of shorter wavelengths of light of a certain level or higher, a cutting tape with a transmittance of 30% or more at a wavelength of 400 nm has been disclosed (see Patent Document 1). This cutting tape serves as a support sheet. Furthermore, this cutting tape is used in conjunction with an adhesive film with a transmittance of 20% or less at a wavelength of 400 nm.

[0013] Existing technical documents

[0014] Patent documents

[0015] Patent Document 1: Japanese Patent Application Publication No. 2010-74129 Summary of the Invention

[0016] The technical problem to be solved by the present invention

[0017] However, the transmittance of the cutting tape disclosed in Patent Document 1 at wavelengths shorter than 400 nm is unknown. Furthermore, this cutting tape is used integrated with an adhesive film intended to bond a semiconductor chip (corresponding to the workpiece) to a target location, rather than to form a protective film on the back of the semiconductor chip. Moreover, the transmittance of the cutting tape and adhesive film at a wavelength of 400 nm is limited so that it can be observed from the cutting tape side whether there is any peeling between them. Therefore, the article disclosed in Patent Document 1, which integrates a cutting tape and an adhesive film, is not a composite sheet for forming a protective film. Furthermore, the light transmission-related properties sought for the cutting tape and adhesive film may naturally differ depending on their intended use.

[0018] In contrast, composite sheets for forming protective films that can be printed using lasers with shorter wavelengths than before are still unknown.

[0019] The purpose of this invention is to provide a composite sheet for forming a protective film, which comprises a support sheet and a protective film for forming a protective film. The protective film for forming a protective film can be formed from the protective film for protecting any position of a workpiece or a workpiece processed by means of the protective film for forming a protective film composite sheet. The protective film for forming a protective film composite sheet can be printed by irradiating the protective film for forming a protective film or the protective film with a shorter wavelength than conventionally from the outside of the support sheet side of the protective film composite sheet through the support sheet.

[0020] Furthermore, the present invention aims to provide a protective film forming film that can constitute the composite sheet for forming the protective film.

[0021] Technical means to solve technical problems

[0022] The present invention provides a protective film for forming a film with a transmittance of less than 60% for light with a wavelength of 355 nm.

[0023] The present invention provides a composite sheet for forming a protective film, comprising a support sheet and a protective film forming film disposed on one side of the support sheet, wherein the support sheet has a transmittance of 20% or more for light with a wavelength of 355nm, and the protective film forming film is the protective film forming film of the present invention.

[0024] In the composite sheet for forming a protective film of the present invention, the transmittance of the support sheet to light with a wavelength of 355 nm can be equal to or greater than the transmittance of the protective film for forming a protective film to light with a wavelength of 355 nm.

[0025] In the protective film forming composite sheet of the present invention, the protective film forming composite sheet is used to be attached to the back side of a semiconductor wafer, wherein there may be no through trench between the back side of the semiconductor wafer and the circuit forming surface opposite to the back side.

[0026] The protective film forming composite sheet of the present invention is used to form a protective film at any position of a workpiece obtained by processing a workpiece. The protective film forming film is used to be attached to any position of the workpiece. When the protective film forming film is curable, the cured product of the protective film forming film is the protective film. When the protective film forming film is non-curable, the protective film forming film attached to any position of the workpiece is the protective film. The protective film forming composite sheet of the present invention is used to: after attaching the protective film forming film in the protective film forming composite sheet to any position of the workpiece, and through the support sheet, irradiate the protective film forming film or the protective film in the protective film forming composite sheet with a laser from the outside of the support sheet side of the protective film forming composite sheet, thereby printing words on the protective film forming film or the protective film.

[0027] This invention provides a method for manufacturing a workpiece with a protective film. The method comprises a workpiece obtained by machining a workpiece and a protective film disposed at any position on the workpiece. The protective film is formed from a protective film forming film in a protective film forming composite sheet of this invention. When the protective film forming film is curable, the cured product of the protective film forming film is the protective film; when the protective film forming film is non-curable, the protective film formed after being attached to any position on the workpiece is the protective film. The method for manufacturing the workpiece with a protective film includes the following steps: forming the protective film in the protective film forming composite sheet... The process includes: an attachment step whereby a protective film is attached to a target position on a workpiece to create a first laminate on which the protective film forming composite sheet is disposed; a printing step whereby, through a support sheet, a laser with a wavelength of 355 nm is irradiated onto the protective film forming composite sheet or the protective film in the first laminate from the outside of the support sheet side of the protective film forming composite sheet to print characters onto the protective film forming film or the protective film; and a processing step whereby the workpiece is processed after the printing step to create a workpiece workpiece. When the protective film forming film is curable, a curing step is further performed after the attachment step to form the protective film by curing the protective film forming film.

[0028] This invention provides a method for manufacturing a workpiece with a protective film. The method comprises a workpiece obtained by machining a workpiece and a protective film disposed at any position on the workpiece. The protective film is formed from a protective film forming film of this invention. When the protective film forming film is curable, the cured product of the protective film forming film is the protective film. When the protective film forming film is non-curable, the protective film formed after being attached to any position on the workpiece is the protective film. The method for manufacturing the workpiece with a protective film includes the following steps: attaching the protective film forming film to... The process involves attaching a second laminate to the workpiece by placing the protective film forming film or protective film on the workpiece at the target position of the workpiece; after the attachment process, a printing process is performed by directly irradiating the protective film forming film or protective film in the second laminate with a laser of wavelength of 355nm from the outside of the protective film forming film or protective film opposite to the workpiece side, thereby printing characters on the protective film forming film or protective film; and a processing process is performed by processing the workpiece after the printing process to produce the workpiece workpiece. When the protective film forming film is curable, a curing process is further performed after the attachment process by curing the protective film forming film to form the protective film.

[0029] Invention Effects

[0030] According to the present invention, a composite sheet for forming a protective film can be provided, comprising a support sheet and a protective film for forming a protective film. The protective film for forming a protective film can be formed from the protective film for protecting any position of a workpiece or a workpiece processed therefrom. For the protective film for forming a composite sheet, a laser with a shorter wavelength than conventional can be irradiated from the outside of the support sheet side of the protective film for forming a composite sheet, thereby printing words on the protective film for forming a composite sheet.

[0031] Furthermore, according to the present invention, a protective film forming film that can constitute the protective film forming composite sheet can be provided. Attached Figure Description

[0032] Figure 1 A cross-sectional view illustrating an example of a composite sheet for forming a protective film according to one embodiment of the present invention.

[0033] Figure 2 A cross-sectional view illustrating another example of a composite sheet for forming a protective film according to one embodiment of the present invention.

[0034] Figure 3A cross-sectional view illustrating yet another example of a protective film forming composite sheet according to one embodiment of the present invention.

[0035] Figure 4 A cross-sectional view illustrating yet another example of a protective film forming composite sheet according to one embodiment of the present invention.

[0036] Figure 5A This is a cross-sectional view illustrating an example of a method for manufacturing a semiconductor chip with a protective film when using a composite sheet for forming a protective film according to one embodiment of the present invention.

[0037] Figure 5B This is a cross-sectional view illustrating an example of a method for manufacturing a semiconductor chip with a protective film when using a composite sheet for forming a protective film according to one embodiment of the present invention.

[0038] Figure 5C This is a cross-sectional view illustrating an example of a method for manufacturing a semiconductor chip with a protective film when using a composite sheet for forming a protective film according to one embodiment of the present invention.

[0039] Figure 5D This is a cross-sectional view illustrating an example of a method for manufacturing a semiconductor chip with a protective film when using a composite sheet for forming a protective film according to one embodiment of the present invention.

[0040] Figure 5E This is a cross-sectional view illustrating an example of a method for manufacturing a semiconductor chip with a protective film when using a composite sheet for forming a protective film according to one embodiment of the present invention.

[0041] Explanation of reference numerals in the attached figures

[0042] 101, 102, 103, 104: Composite sheets for forming protective films; 1011: Composite sheets for forming protective films where the protective film has become a protective film; 1012: Composite sheets for forming protective films with printed text; 10, 20, 30: Support sheets; 10a, 20a, 30a: One side (first side) of the support sheet; 13, 23: Films for forming protective films; 13': Protective film; 130': Cut protective film; 9: Semiconductor wafer; 9a: Circuit forming side of the semiconductor wafer; 9b: Back side of the semiconductor wafer; 9': Semiconductor chip; 91: Semiconductor chip with a protective film; 901: First laminate; 9011: Cured first laminate; 9012: First laminate with printed text and cured; L: Laser. Detailed Implementation

[0043] ◇ Membrane for protective film formation

[0044] According to one embodiment of the present invention, the protective film for forming has a transmittance of less than 60% for light with a wavelength of 355 nm (in this specification, it is sometimes abbreviated as "light (355 nm)").

[0045] As will be described later, the protective film forming film of this embodiment can, for example, be laminated with a support sheet to form a composite sheet for forming a protective film.

[0046] The protective film forming method of this embodiment can form a protective film for protecting any position of a workpiece being processed, and can also form a protective film for protecting any position of a workpiece before processing.

[0047] Examples of workpieces include semiconductor wafers and semiconductor device panels. Semiconductor device panels are used in the manufacturing process of semiconductor devices. As a specific example, a semiconductor device panel can be formed by arranging multiple semiconductor devices in a circular, rectangular, or other shaped area using a semiconductor device in which one or more electronic components are sealed with a sealing resin.

[0048] In this specification, the article obtained by processing a workpiece is referred to as a "workpiece processed item". For example, when the workpiece is a semiconductor wafer, a semiconductor chip can be listed as a workpiece processed item.

[0049] For example, when the workpiece is a semiconductor wafer, the support sheet can be used to fix a semiconductor wafer having a protective film forming film or protective film on the back side.

[0050] For example, when the workpiece is a semiconductor wafer, by using the protective film for forming according to this embodiment, a protective film can be formed on the side of the semiconductor wafer and semiconductor chip opposite to the circuit formation surface (in this specification, it is sometimes referred to as the "back side"). In this specification, the workpiece having the protective film is sometimes referred to as a "workpiece with a protective film", and the semiconductor chip having a protective film on the back side is sometimes referred to as a "semiconductor chip with a protective film".

[0051] The protective film is soft and can be easily attached to the workpiece and the workpiece being processed.

[0052] The protective film for forming in this embodiment can function as a protective film either by curing or by remaining uncured. When the protective film functions as a protective film in its uncured state, it can be considered as having formed a protective film, for example, at the stage of being attached to a target location on a workpiece.

[0053] The protective film forming film of this embodiment has low light transmittance (355nm) and high light absorption (355nm). Therefore, by irradiating the protective film forming film or the protective film with a laser of a shorter wavelength than conventional, such as 355nm, it is possible to effectively print text on the protective film forming film or the protective film.

[0054] Furthermore, by irradiating the protective film forming film of this embodiment with this short-wavelength laser, printing can be performed with high precision compared to the past.

[0055] In addition, the protective film forming film and its cured material (e.g., the protective film) exhibit approximately the same transmittance and approximately the same absorptivity for the same wavelength of light.

[0056] Furthermore, when the protective film forming film of this embodiment is combined with a support sheet having a certain level or higher transmittance at 355nm to form a composite sheet for forming a protective film, by irradiating the protective film forming film or the protective film in the composite sheet with a laser of a shorter wavelength than conventional, such as 355nm, from the outside of the support sheet side of the composite sheet, through the support sheet, it is possible to effectively imprint text on the protective film forming film or the protective film. Moreover, the imprinted text can be clearly identified from the outside of the composite sheet, through the support sheet.

[0057] In this specification, unless otherwise stated, "printing" as described above means that, through a support sheet, a laser is irradiated onto the protective film forming membrane or protective film in the protective film forming composite sheet from the outside of the support sheet side of the protective film forming composite sheet, thereby printing on the protective film forming membrane or protective film.

[0058] In this specification, unless otherwise stated, "identification of the protective film forming film or the printing on the protective film" as described above refers to identifying the protective film forming film or the printing on the protective film from the outside of the support sheet side of the composite sheet for forming the protective film, with the support sheet in between.

[0059] In the past, lasers with wavelengths of 532nm or 1064nm were commonly used in the formation of protective films or in the printing of protective films.

[0060] In contrast, printing accuracy has been improved by using lasers with wavelengths shorter than those of the past, such as 355nm.

[0061] In this instruction manual, "able to print well" means that the printing suitability is good, that is, the printing can be done in a way that allows the target characters to be correctly identified. In addition, "able to identify the printed characters well" means that the printed characters are visible, that is, the printed characters can be identified visually without error.

[0062] The transmittance of the protective film for forming light (355 nm) can, for example, be any range of 55% or less, 45% or less, 35% or less, and 25% or less. By making the transmittance of the protective film for forming below the upper limit value, the printability of the protective film for forming or the protective film, and their print visibility, are further improved.

[0063] There is no particular limitation on the lower limit of the transmittance of the protective film for light (355nm). For example, it can be 0%. For example, it is easier to manufacture the protective film for light (355nm) with a transmittance of 1% or more, and the transmittance can also be 10% or more.

[0064] The transmittance of the protective film for forming light (355 nm) can be appropriately adjusted within a range set by any combination of the aforementioned lower and upper limits. For example, in one embodiment, the transmittance of the protective film for forming can be any range of 1–60%, 1–55%, 1–45%, 1–35%, and 1–25%, or any range of 10–60%, 10–55%, 10–45%, 10–35%, and 10–25%. However, these ranges are merely one example of the transmittance of the protective film for forming.

[0065] As described above, the protective film forming membrane can be either curable or non-curable.

[0066] The protective film for curing can be either thermosetting or energy-curable, or it can have both thermosetting and energy-curable properties.

[0067] In this specification, "energy rays" refers to rays containing energy quanta within electromagnetic waves or charged particle beams. Examples of such rays include ultraviolet light, radiation, and electron beams. For instance, ultraviolet light can be emitted by using high-pressure mercury lamps, fusion H lamps, xenon lamps, black lights, or LED lights as ultraviolet light sources. Electron beams can be emitted by irradiating electrons generated using electron beam accelerators or similar devices.

[0068] Furthermore, in this specification, "energy-ray curing property" refers to the property of curing by irradiation with energy rays, and "non-energy-ray curing property" refers to the property of not curing even when irradiated with energy rays.

[0069] Furthermore, in this specification, "non-curing" means the property that it will not cure even by any means such as heating or irradiation with energy rays.

[0070] When a protective film is formed by thermosetting the film for forming a protective film, unlike when it is cured by irradiation with energy rays, it is fully cured by heating. Therefore, even if the thickness of the protective film for forming a protective film is relatively large, a protective film with high protective performance can be formed. In addition, by using conventional heating methods such as heating ovens, many protective film forming films can be heated and thermoset at the same time.

[0071] When a protective film is cured by irradiation with energy rays to form a protective film, unlike when it is thermally cured, the composite sheet for forming the protective film does not need to be heat-resistant, and a wider range of protective film forming composite sheets can be formed. Furthermore, by irradiation with energy rays, it can be cured in a short time.

[0072] When the protective film is used as a protective film without curing it, the curing process can be omitted, thus enabling the manufacture of workpieces with a simplified process.

[0073] Regardless of whether the protective film forming film is curable or non-curable, it can consist of a single layer or multiple layers. When the protective film forming film is curable, whether thermosetting or radiation-curable, it can also consist of a single layer or multiple layers. When the protective film forming film consists of multiple layers, these layers can be identical or different from each other, and there are no particular limitations on the combination of these layers.

[0074] In this specification, the term "multiple layers may be the same as each other or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same". Furthermore, "multiple layers may be different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

[0075] Regardless of whether the protective film for forming is curable or non-curable, the thickness of the protective film for forming is preferably 1–100 μm, more preferably 3–80 μm, and particularly preferably 5–60 μm, for example, any range from 5–40 μm and 5–20 μm. When the protective film for forming is curable, regardless of whether it is thermosetting or energy-cured, the thickness of the protective film for forming is also preferably 1–100 μm, more preferably 3–80 μm, and particularly preferably 5–60 μm, for example, any range from 5–40 μm and 5–20 μm. By making the thickness of the protective film for forming at or above the lower limit value, a protective film with higher protective performance can be formed. By making the thickness of the protective film for forming at or below the upper limit value, excessive thickness can be avoided.

[0076] The “thickness of the protective film forming membrane” refers to the overall thickness of the protective film forming membrane. For example, the thickness of the protective film forming membrane, which is composed of multiple layers, refers to the total thickness of all the layers that make up the protective film forming membrane.

[0077] Compositions for forming protective films

[0078] A protective film forming film can be formed using a protective film forming composition containing its constituent materials. For example, a protective film forming film can be formed by coating the surface to which it is to be formed with the protective film forming composition and then drying it as needed. The content ratio of the components that do not vaporize at room temperature in the protective film forming composition is generally the same as the content ratio of the components in the protective film forming film. In this specification, "room temperature" refers to a temperature without special cooling or heating, i.e., a normal temperature, such as temperatures of 15 to 25°C.

[0079] Thermosetting protective film forming films can be formed using thermosetting protective film forming compositions, energy-curable protective film forming films can be formed using energy-curable protective film forming compositions, and non-curable protective film forming films can be formed using non-curable protective film forming compositions. Furthermore, in this specification, when a protective film forming film possesses both thermosetting and energy-curable properties, and the contribution of thermosetting to the formation of the protective film is greater than the contribution of energy-curing, the protective film forming film is considered a thermosetting film. Conversely, when the contribution of energy-curing to the formation of the protective film is greater than the contribution of thermosetting, the protective film forming film is considered an energy-curable film.

[0080] The coating of the protective film forming composition can be carried out using known methods, such as air knife coating machines, blade coaters, bar coaters, gravure coating machines, roller coaters, roller knife coaters, screen coaters, die coaters, doctor blade coaters, screen coaters, Mayer bar coaters, kiss coaters, and other coating machines.

[0081] Regardless of whether the protective film forming film is curable or non-curable, the drying conditions for the protective film forming composition are not particularly limited. Furthermore, when the protective film forming film is curable, regardless of whether it is thermosetting or energy-curable, the drying conditions for the protective film forming composition are also not particularly limited. However, when the protective film forming composition contains the solvent described below, heat drying is preferred. Furthermore, the protective film forming composition containing the solvent is preferably heat-dried at 70–130°C for 10 seconds to 5 minutes. However, it is preferable to heat-dry the thermosetting protective film forming composition in a manner that does not allow the thermosetting protective film forming composition itself to heat-cur with the thermosetting protective film forming film formed from the composition.

[0082] The following sections will describe films for forming thermosetting protective films, films for forming energy-curable protective films, and films for forming non-curable protective films.

[0083] ◎Thermosetting protective film forming membrane

[0084] When a thermosetting protective film is applied to the target position of a workpiece and thermally cured to form a protective film, the curing conditions are not particularly limited as long as the degree of curing allows the protective film to fully perform its function. The appropriate curing conditions can be selected according to the type of thermosetting protective film.

[0085] For example, the heating temperature for heat curing the thermosetting protective film is preferably 100–200°C, more preferably 110–180°C, and particularly preferably 120–170°C. Furthermore, the heating time for heat curing is preferably 0.5–5 hours, more preferably 0.5–3 hours, and particularly preferably 1–2 hours.

[0086] As a preferred thermosetting protective film forming film, an example is a thermosetting protective film forming film containing a polymer component (A) and a thermosetting component (B). The polymer component (A) is considered to be a component formed by a polymerization reaction of a polymeric compound. Furthermore, the thermosetting component (B) is a component capable of undergoing a curing (polymerization) reaction induced by heat. Additionally, the polymerization reaction described in this specification also includes a condensation polymerization reaction.

[0087] <Composition for forming thermosetting protective films (III-1)>

[0088] Preferred compositions for forming thermosetting protective films include, for example, a thermosetting protective film forming composition (III-1) containing the polymer component (A) and the thermosetting component (B) (in this specification, it is sometimes simply abbreviated as "composition (III-1)").

[0089] [Polymer component (A)]

[0090] Polymer component (A) is used to impart film-forming properties and flexibility to the film used for forming thermosetting protective films. Polymer component (A) is thermoplastic and not thermosetting. Furthermore, in this specification, the polymer compound also includes products of a polycondensation reaction.

[0091] The polymer component (A) contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0092] Examples of polymer components (A) include acrylic resins, urethane resins, phenoxy resins, silicone resins, saturated polyester resins, etc., with acrylic resins being preferred.

[0093] As the acrylic resin in polymer component (A), known acrylic polymers can be cited.

[0094] The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, more preferably 100,000 to 1,500,000. By setting the weight-average molecular weight of the acrylic resin to the lower limit or above, the shape stability (time stability during storage) of the thermosetting protective film is improved. Furthermore, by setting the weight-average molecular weight of the acrylic resin to the upper limit or below, the thermosetting protective film becomes easier to follow the uneven surface of the substrate, and the generation of voids between the substrate and the thermosetting protective film can be further suppressed.

[0095] In addition, unless otherwise specified in this specification, “weight-average molecular weight” refers to the converted value of polystyrene determined by gel permeation chromatography (GPC).

[0096] The glass transition temperature (Tg) of the acrylic resin is preferably -60 to 70°C, more preferably -30 to 50°C. By setting the Tg of the acrylic resin to the lower limit or above, for example, the adhesion between the cured film for forming the protective film and the support sheet can be suppressed, and the peelability of the support sheet can be appropriately improved. Furthermore, by setting the Tg of the acrylic resin to the upper limit or below, the adhesion between the thermosetting protective film for forming the film and its cured film and the adherend can be improved.

[0097] When an acrylic resin has m types of structural units (m is an integer greater than or equal to 2), and each of the m monomers from which these structural units are derived is 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.

[0098] [Mathematical Expression 1]

[0099]

[0100] In the formula, Tg is the glass transition temperature of acrylic resin; m is an integer greater than or equal to 2; Tg k W is the glass transition temperature of the homopolymer of monomer m; k W represents the mass fraction of structural unit m derived from monomer m in acrylic resin. k It satisfies the following formula.

[0101] [Mathematical Expression 2]

[0102]

[0103] In the formula, m and W k With the m and W k same.

[0104] As the Tg k The values ​​can be found in polymer datasheets or adhesive manuals. For example, the Tg of methyl acrylate homopolymers. k The Tg of methyl methacrylate homopolymer at 10℃ k The Tg of the homopolymer of 2-hydroxyethyl acrylate at 105℃ k The temperature is -15℃.

[0105] Examples of acrylic resins include polymers of one or more (meth)acrylates; copolymers of two or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-hydroxymethylacrylamide.

[0106] Examples of (meth)acrylates constituting acrylic resins include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, isooctyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, and isononyl methacrylate. Alkyl esters, such as decyl methacrylate, undecyl methacrylate, dodecyl methacrylate (laurate methacrylate), tridecyl methacrylate, tetradecyl methacrylate (myristyl methacrylate), pentadecyl methacrylate, hexadecyl methacrylate (palmitoyl methacrylate), heptadecanyl methacrylate, and octadecyl methacrylate (stearate methacrylate), are chain alkyl esters in which the alkyl group has a chain structure with 1 to 18 carbon atoms.

[0107] Isoborneol ester (meth)acrylate, dicyclopentyl ester (meth)acrylate, and other cycloalkyl esters of (meth)acrylate;

[0108] (Meth)benzyl acrylate and other (meth)acrylate aralkyl esters;

[0109] (Meth)acrylate dicyclopentenyl ester and other (meth)acrylate cycloalkenyl esters;

[0110] (Meth)acrylate dicyclopentenyloxyethyl ester and other (meth)acrylate cyclopentenyloxyalkyl esters;

[0111] (meth)acrylimide;

[0112] (Meth)acrylates containing glycidyl groups, such as glycidyl acrylate;

[0113] Hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, and other hydroxyl-containing methacrylates;

[0114] (Meth)acrylates such as N-methylaminoethyl methacrylate and other (meth)acrylates containing substituted amino groups. Here, "substituted amino group" refers to a group in which one or two hydrogen atoms of the amino group are replaced by a group other than a hydrogen atom.

[0115] In addition, in this specification, "(meth)acrylic acid" is a concept that includes both "acrylic acid" and "methacrylic acid". Similar terms to "(meth)acrylic acid" are also used, for example, "(meth)acryloyl" refers to the concept that includes both "acryloyl" and "methacryloyl", and "(meth)acrylate" refers to the concept that includes both "acrylate" and "methacrylate".

[0116] Acrylic resins can be, for example, resins that, in addition to the (meth)acrylates, also copolymerize one or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-hydroxymethylacrylamide.

[0117] The monomers that make up acrylic resin can be just one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0118] Acrylic resins may possess functional groups such as vinyl, (meth)acryloyl, amino, hydroxyl, carboxyl, and isocyanate groups, which enable them to bond with other compounds. These functional groups of the acrylic resin can be bonded to other compounds via a crosslinking agent (F) described later, or they can be directly bonded to other compounds without the crosslinking agent (F). By bonding the acrylic resin to other compounds through these functional groups, there is a tendency to improve the reliability of the package obtained using a composite sheet for forming a protective film.

[0119] In this invention, as the polymer component (A), a thermoplastic resin other than acrylic resin (hereinafter sometimes simply referred to as "thermoplastic resin") may be used alone instead of acrylic resin, or both acrylic resin and a thermoplastic resin other than acrylic resin may be used simultaneously. By using the thermoplastic resin, the peelability of the protective film from the support sheet is improved, or the thermosetting protective film forming film becomes easier to follow the uneven surface of the substrate, further suppressing the formation of voids between the substrate and the thermosetting protective film forming film.

[0120] The weight-average molecular weight of the thermoplastic resin is preferably 1,000 to 100,000, more preferably 3,000 to 80,000.

[0121] The glass transition temperature (Tg) of the thermoplastic resin is preferably -30 to 150°C, more preferably -20 to 120°C.

[0122] Examples of thermoplastic resins include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

[0123] The thermoplastic resin contained in the composition (III-1) and the thermosetting protective film forming film may be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0124] In composition (III-1), the ratio of the content of polymer component (A) to the total content of all components except 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 independent of the type of polymer component (A), preferably 10 to 85% by mass, more preferably 15 to 70% by mass, even more preferably 20 to 60% by mass, for example, it can be any range of 20 to 45% by mass and 20 to 35% by mass, or any range of 35 to 60% by mass and 45 to 60% by mass.

[0125] Polymer component (A) is sometimes also a thermosetting component (B). In this invention, when composition (III-1) contains a component that is both a polymer component (A) and a thermosetting component (B), composition (III-1) is considered to contain both polymer component (A) and thermosetting component (B).

[0126] [Thermosetting component (B)]

[0127] Thermosetting component (B) is the component used to cure the thermosetting protective film.

[0128] The thermosetting component (B) contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0129] Examples of thermosetting components (B) include epoxy thermosetting resins, polyimide resins, and unsaturated polyester resins, with epoxy thermosetting resins being preferred.

[0130] (Epoxy thermosetting resins)

[0131] Epoxy thermosetting resins are formed from epoxy resin (B1) and thermosetting agent (B2).

[0132] The epoxy thermosetting resin contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0133] ·Epoxy resin (B1)

[0134] As for epoxy resin (B1), well-known epoxy resins can be listed, such as multifunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrides, o-cresol phenolic varnish epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin, and other epoxy compounds with more than one function.

[0135] As the epoxy resin (B1), an epoxy resin having unsaturated hydrocarbon groups can be used. The compatibility of epoxy resins with unsaturated hydrocarbon groups with acrylic resins is higher than that of epoxy resins without unsaturated hydrocarbon groups with acrylic resins. Therefore, by using epoxy resins with unsaturated hydrocarbon groups, the reliability of workpieces with a protective film obtained using a protective film forming composite sheet is improved.

[0136] As epoxy resins having unsaturated hydrocarbon groups, examples include compounds in which a portion of the epoxy groups of multifunctional epoxy resins are converted into groups having unsaturated hydrocarbon groups. These compounds can be obtained, for example, by adding an addition reaction of (meth)acrylic acid or a derivative thereof to the epoxy groups.

[0137] Furthermore, examples of epoxy resins containing unsaturated hydrocarbon groups include compounds formed by direct bonding of unsaturated hydrocarbon groups to aromatic rings that constitute epoxy resins.

[0138] Unsaturated hydrocarbon groups are unsaturated groups that can polymerize. Specific examples include methine (vinyl), 2-propenyl (allyl), (meth)acryloyl, (meth)acrylamido, etc., with acryloyl being preferred.

[0139] The number average molecular weight of epoxy resin (B1) is not particularly limited, but from the perspective of curability of the film for forming thermosetting protective film and the strength and heat resistance of the protective film, it is preferably 300 to 30000, more preferably 300 to 10000, and particularly preferably 300 to 3000.

[0140] The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1000 g / eq, more preferably 150 to 950 g / eq.

[0141] Epoxy resin (B1) can be used alone or in combination with two or more. When two or more are used, their combination and ratio can be chosen arbitrarily.

[0142] • Thermosetting agent (B2)

[0143] The thermosetting agent (B2) functions as a curing agent for epoxy resin (B1).

[0144] As a thermosetting agent (B2), examples include compounds having two or more functional groups in one molecule that can react with epoxy groups. Examples of such functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups formed by anhydride modification of acid groups; phenolic hydroxyl groups, amino groups, or groups formed by anhydride modification of acid groups are preferred, and phenolic hydroxyl groups or amino groups are more preferred.

[0145] Among thermosetting agents (B2), phenolic curing agents with phenolic hydroxyl groups include, for example, polyfunctional phenolic resins, biphenyl, phenolic varnish-type phenolic resins, dicyclopentadiene-type phenolic resins, and arylalkyl-type phenolic resins.

[0146] Among thermosetting agents (B2), amine curing agents containing amino groups are, for example, dicyandiamide.

[0147] Thermosetting agent (B2) may have unsaturated hydrocarbon groups.

[0148] Examples of thermosetting agents (B2) with unsaturated hydrocarbon groups include compounds in which a portion of the hydroxyl groups of a phenolic resin are replaced by groups with unsaturated hydrocarbon groups, and compounds in which groups with unsaturated hydrocarbon groups are directly bonded to the aromatic rings of a phenolic resin.

[0149] The unsaturated hydrocarbon group in the thermosetting agent (B2) is the same as the unsaturated hydrocarbon group in the epoxy resin having unsaturated hydrocarbon groups described above.

[0150] When using a phenolic curing agent as a thermosetting agent (B2), from the perspective of improving the peelability of the protective film from the support sheet, it is preferable that the thermosetting agent (B2) has a high softening point or glass transition temperature.

[0151] In the thermosetting agent (B2), the number average molecular weight of resin components such as polyfunctional phenolic resin, phenolic varnish-type phenolic resin, dicyclopentadiene-type phenolic resin, and aralkyl-type phenolic resin is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000.

[0152] In the thermosetting agent (B2), the molecular weight of non-resin components such as biphenyl hydroquinone and dicyandiamide is not particularly limited, but is preferably 60 to 500.

[0153] Thermosetting agent (B2) can be used alone or in combination with two or more. When two or more are used, their combination and ratio can be chosen arbitrarily.

[0154] In composition (III-1) and the thermosetting protective film forming film, the content of thermosetting agent (B2) is preferably 0.1 to 100 parts by mass relative to 100 parts by mass of epoxy resin (B1), more preferably 0.5 to 50 parts by mass, for example, any range from 0.5 to 25 parts by mass, 0.5 to 10 parts by mass, and 0.5 to 5 parts by mass. By setting the content of thermosetting agent (B2) to the lower limit or above, it becomes easier to cure the thermosetting protective film forming film. By setting the content of thermosetting agent (B2) to the upper limit or below, the moisture absorption rate of the thermosetting protective film forming film is reduced, and the reliability of the encapsulation obtained by using the protective film forming composite sheet is further improved.

[0155] In the composition (III-1) and the thermosetting protective film forming film, the content of the thermosetting component (B) (e.g., the total content of epoxy resin (B1) and 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 polymer component (A). For example, it can be any range from 5 to 40 parts by mass, 5 to 20 parts by mass, and 5 to 10 parts by mass, or any range from 40 to 80 parts by mass, 50 to 75 parts by mass, and 60 to 75 parts by mass. By setting the content of the thermosetting component (B) to the above range, for example, the adhesion between the cured film of the protective film forming film and the support sheet is suppressed, and the peelability of the support sheet is improved.

[0156] [Curning Accelerator (C)]

[0157] The composition (III-1) and the film for forming the thermosetting protective film may contain a curing accelerator (C). The curing accelerator (C) is a component used to adjust the curing speed of the composition (III-1).

[0158] Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles (imidazoles in which one or more hydrogen atoms are replaced by groups other than hydrogen atoms) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organophosphines (phosphines in which one or more hydrogen atoms are replaced by organic groups) such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

[0159] The curing accelerator (C) contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0160] When using curing accelerator (C), the content of curing accelerator (C) in composition (III-1) and the thermosetting protective film forming film is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the thermosetting component (B), more preferably 0.1 to 7 parts by mass. By setting the content of curing accelerator (C) to the lower limit or above, the effects of using curing accelerator (C) can be obtained more significantly. By setting the content of curing accelerator (C) to the upper limit or below, for example, the effect of suppressing the highly polar curing accelerator (C) from migrating to the bonding interface with the adhered object in the thermosetting protective film forming film under high temperature and high humidity conditions becomes higher. As a result, the reliability of the workpiece with a protective film obtained by using the protective film forming composite sheet is further improved.

[0161] [Filling Material (D)]

[0162] The composition (III-1) and the thermosetting protective film forming film may contain a filler material (D). By including the filler material (D) in the thermosetting protective film forming film, it becomes easier to adjust the coefficient of thermal expansion of the thermosetting protective film forming film and the protective film. By optimizing the coefficient of thermal expansion of the workpiece to which the protective film is formed, the reliability of the workpiece with the protective film obtained by using the composite sheet for forming the protective film is further improved. In addition, by including the filler material (D) in the thermosetting protective film forming film, it is also possible to reduce the moisture absorption rate of the protective film and improve its heat dissipation.

[0163] The filler material (D) can be either an organic filler material or an inorganic filler material, preferably an inorganic filler material.

[0164] Preferred inorganic filler materials include, for example, powders of silica, alumina, talc, calcium carbonate, titanium dioxide, red iron oxide, silicon carbide, and boron nitride; beads obtained by spherizing these inorganic filler materials; surface modifiers of these inorganic filler materials; single-crystal fibers of these inorganic filler materials; and glass fibers.

[0165] The inorganic filler material is preferably silicon dioxide or aluminum oxide, and more preferably silicon dioxide.

[0166] The filler material (D) contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0167] When using filler material (D), the ratio of the content of filler material (D) in composition (III-1) to the total content of all components except the solvent (i.e., the ratio of the content of filler material (D) in the thermosetting protective film forming film to the total mass of the thermosetting protective film forming film) is preferably 15 to 70% by mass, more preferably 30 to 60% by mass, for example, any range of 35 to 60% by mass, 40 to 60% by mass, and 45 to 60% by mass, or any range of 30 to 55% by mass, 30 to 50% by mass, and 30 to 45% by mass. By setting the ratio to the above range, it becomes easier to adjust the coefficient of thermal expansion of the thermosetting protective film forming film and the protective film.

[0168] [Coupled agent (E)]

[0169] Composition (III-1) and the thermosetting protective film forming film may contain a coupling agent (E). By using a coupling agent (E) having functional groups capable of reacting with inorganic or organic compounds, the adhesion and bonding strength of the thermosetting protective film forming film to the adherend can be improved. Furthermore, by using the coupling agent (E), the water resistance of the protective film formed from the thermosetting protective film forming film is improved without compromising its heat resistance.

[0170] The coupling agent (E) is preferably a compound having functional groups that can react with functional groups of polymer component (A), thermosetting component (B), etc., and more preferably a silane coupling agent.

[0171] Preferred silane coupling agents include, for example, 3-glycidyl etheroxypropyltrimethoxysilane, 3-glycidyl etheroxypropylmethyldiethoxysilane, 3-glycidyl etheroxypropyltriethoxysilane, 3-glycidyl etheroxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-(2-aminoethylamino)propyltrimethoxysilane. Methoxysilane, 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinepropyltrimethoxysilane, 3-ureapropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole silane, etc.

[0172] The coupling agent (E) contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0173] When using coupling agent (E), in the composition (III-1) and the thermosetting protective film forming film, the content of coupling agent (E) is preferably 0.03 to 10 parts by mass relative to 100 parts by mass of the total content of polymer component (A) and thermosetting component (B), more preferably 0.05 to 5 parts by mass, and particularly preferably 0.1 to 2 parts by mass. By setting the content of coupling agent (E) to the lower limit or above, the effects of using coupling agent (E), such as improving the dispersibility of filler material (D) in the resin or improving the adhesion between the thermosetting protective film forming film and the adherend, can be obtained more significantly. Furthermore, by setting the content of coupling agent (E) to the upper limit or below, the occurrence of outgassing can be further suppressed.

[0174] [Crosslinking agent (F)]

[0175] When the above-mentioned acrylic resin or other components having functional groups such as vinyl, (meth)acryloyl, amino, hydroxyl, carboxyl, and isocyanate groups that can bond with other compounds are used as polymer component (A), the composition (III-1) and the thermosetting protective film forming film may contain a crosslinking agent (F). The crosslinking agent (F) is a component used to crosslink the functional groups in polymer component (A) with other compounds. By crosslinking in this way, the initial adhesive force and cohesive force of the thermosetting protective film forming film can be adjusted.

[0176] Examples of crosslinking agents (F) include organic polyisocyanate compounds, organic polyimide compounds, metal chelate crosslinking agents (crosslinking agents with metal chelate structures), and aziridine crosslinking agents (crosslinking agents with aziridine groups).

[0177] The crosslinking agent (F) contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0178] When using a crosslinking agent (F), in composition (III-1), the content of crosslinking agent (F) is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of polymer component (A), more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass. By setting the content of crosslinking agent (F) to the lower limit or above, the effects of using crosslinking agent (F) can be obtained more significantly. Furthermore, by setting the content of crosslinking agent (F) to the upper limit or below, the excessive use of crosslinking agent (F) is suppressed.

[0179] [Energy-cured resin (G)]

[0180] The composition (III-1) and the thermosetting protective film forming film may contain an energy-curable resin (G). By containing the energy-curable resin (G) in the thermosetting protective film forming film, its properties can be changed by irradiation with energy rays.

[0181] Energy-curable resin (G) is obtained by polymerizing (curing) an energy-curable compound.

[0182] Examples of energy-curable compounds include those having at least one polymerizable double bond within the molecule, preferably acrylate compounds having a (meth)acryloyl group.

[0183] Examples of such 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-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and other (meth)acrylates containing a chain-like aliphatic backbone; dicyclopentyl di(meth)acrylate and other (meth)acrylates containing a cyclic aliphatic backbone; polyethylene glycol di(meth)acrylate and other polyalkylene glycol (meth)acrylates; low-polyester (meth)acrylates; urethane (meth)acrylate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the aforementioned polyalkylene glycol (meth)acrylates; itaconic acid oligomers, etc.

[0184] The weight-average molecular weight of the energy-curable compound is preferably 100 to 30,000, more preferably 300 to 10,000.

[0185] The energy-curable compound used for polymerization can be one or more compounds, and when there are more than two compounds, their combination and ratio can be arbitrarily selected.

[0186] The energy-curable resin (G) contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0187] When using an energy-curable resin (G), the content of the energy-curable resin (G) in the composition (III-1) relative to the total mass of the composition (III-1) is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, and particularly preferably 10 to 85% by mass.

[0188] [Photopolymerization initiator (H)]

[0189] When the composition (III-1) and the thermosetting protective film forming film contain an energy-curable resin (G), a photopolymerization initiator (H) may be included in order to efficiently carry out the polymerization reaction of the energy-curable resin (G).

[0190] As the photopolymerization initiator (H) in composition (III-1), examples of photopolymerization initiators that are the same as those that may be contained in the adhesive composition described above can be listed.

[0191] The photopolymerization initiator (H) contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0192] When using a photopolymerization initiator (H), in composition (III-1), the content of photopolymerization initiator (H) is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of energy-curable resin (G), more preferably 1 to 10 parts by mass, and particularly preferably 2 to 5 parts by mass.

[0193] [Coloring agent (I)]

[0194] The composition (III-1) and the thermosetting protective film forming film preferably contain a colorant (I). By using the colorant (I), it is easier to manufacture a protective film forming film with a light transmittance (355 nm) of 60% or less.

[0195] As coloring agents (I), examples of known coloring agents include inorganic pigments, organic pigments, and organic dyes.

[0196] Examples of organic pigments and dyes include, for example, aminium pigments, anthocyanin pigments, croconium pigments, squarylium pigments, azulenium pigments, polymethystylene pigments, naphthoquinone pigments, pyranium pigments, phthalocyanine pigments, naphthocyanin pigments, naphtholactam pigments, azo pigments, and condensed doublet pigments. Nitrogen-based pigments, indigo-based pigments, perinone-based pigments, perylene-based pigments, dioxazine-based pigments, quinacridone-based pigments, isoindolineone-based pigments, quinolineone-based pigments, pyrrole-based pigments, thioindigo-based pigments, metal complex pigments (metal complex salt dyes), dithiol metal complex pigments, indolephenol-based pigments, triarylmethane-based pigments, anthraquinone-based pigments, naphthol-based pigments, methylimino-based pigments, benzimidazole-based pigments, pinantrone-based pigments, and threne-based pigments, etc.

[0197] Examples of inorganic pigments include carbon black, cobalt pigments, iron pigments, chromium pigments, titanium pigments, vanadium pigments, zirconium pigments, molybdenum pigments, ruthenium pigments, platinum pigments, ITO (indium tin oxide) pigments, and ATO (antimony tin oxide) pigments.

[0198] The colorant (I) contained in the composition (III-1) and the thermosetting protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0199] When using colorant (I), the content of colorant (I) in the thermosetting protective film forming film can be appropriately adjusted according to the purpose. For example, by adjusting the content of colorant (I) in the thermosetting protective film forming film, the transmittance of the thermosetting protective film forming film to light (355nm) can be adjusted, thereby adjusting the visibility of the printed text when laser printing on the thermosetting protective film forming film or the protective film. In addition, by adjusting the content of colorant (I) in the thermosetting protective film forming film, the designability of the protective film can be improved, or the grinding marks on the back side of the semiconductor wafer can be made less visible. Taking these points into consideration, in the composition (III-1), the ratio of the content of colorant (I) to the total content of all components except the solvent (i.e., the ratio of the content of 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% by mass, more preferably 0.05 to 9% by mass, and particularly preferably 0.1 to 7% by mass. By setting the ratio above the lower limit, the effects of using colorant (I) can be obtained more significantly. Furthermore, by setting the ratio below the upper limit, excessive use of colorant (I) can be suppressed.

[0200] [General Additives (J)]

[0201] Without impairing the effects of the present invention, the composition (III-1) and the thermosetting protective film forming film may contain general additives (J).

[0202] General additives (J) can be known additives and can be selected arbitrarily according to the purpose without special limitations. Preferred additives include, for example, plasticizers, antistatic agents, antioxidants, gettering agents, and ultraviolet absorbers.

[0203] The general additive (J) contained in the composition (III-1) and the thermosetting protective film forming film can be only one or more. When there are more than two, their combination and ratio can be arbitrarily selected.

[0204] The content of composition (III-1) and general additive (J) for thermosetting protective film formation is not particularly limited and can be appropriately selected according to the purpose.

[0205] [solvent]

[0206] Composition (III-1) preferably further contains a solvent. Composition (III-1) containing a solvent has good operability.

[0207] In addition, unless otherwise specified in this specification, the concept of "solvent" includes not only the solvent that dissolves the target component, but also the dispersion medium that disperses the target component.

[0208] The solvent is not particularly limited, but preferred solvents include, for example, hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropane-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 with amide bonds) such as dimethylformamide and N-methylpyrrolidone.

[0209] The composition (III-1) may contain only one solvent or two or more solvents. When there are two or more solvents, their combination and ratio can be arbitrarily selected.

[0210] Starting from the point that the contained components in the composition (III-1) can be mixed more evenly, solvents contained in the more preferred composition (III-1) include, for example, methyl ethyl ketone, toluene, ethyl acetate, etc.

[0211] The content of solvent in composition (III-1) is not particularly limited; for example, it can be appropriately selected according to the types of components other than the solvent.

[0212] <Preparation Method of Composition for Thermosetting Protective Film Formation>

[0213] Composition (III-1) and other thermosetting protective film forming compositions can be obtained by incorporating the components used to constitute the composition.

[0214] Apart from the difference in the types of admixtures, the thermosetting protective film forming composition can be prepared, for example, by the same method as the adhesive composition described above.

[0215] ◎Membranes for forming protective films that can be cured by energy rays

[0216] When an energy-curable protective film is formed by attaching a film for forming an energy-curable protective film to the target position of a workpiece and curing it with energy rays, there are no particular limitations on the curing conditions, as long as the degree of curing is sufficient to allow the protective film to fully perform its function. It is sufficient to select an appropriate degree of curing based on the type of energy-curable protective film.

[0217] For example, when curing a protective film for energy-curable films with energy rays, the irradiance of the energy rays is preferably 120–280 mW / cm². 2 Furthermore, the intensity of the energy rays during curing is preferably 100–1000 mJ / cm². 2 .

[0218] As a membrane for forming an energy-curable protective film, for example, a membrane containing an energy-curable component (a) can be listed, and a membrane containing an energy-curable component (a) and a filler material is preferred.

[0219] In the film for forming an energy-curable protective film, the energy-curable component (a) is preferably uncured, preferably adhesive, and more preferably uncured and adhesive.

[0220] <Composition for forming protective films that can be cured by energy rays (IV-1)>

[0221] As a preferred composition for forming an energy-curable protective film, examples include, for instance, an energy-curable protective film forming composition (IV-1) containing the energy-curable component (a) (in this specification, it is sometimes simply abbreviated as "composition (IV-1)").

[0222] [Energy-based solidification component (a)]

[0223] The energy-curable component (a) is a component that is cured by irradiation with energy rays. It imparts film-forming properties and flexibility to the film used for forming an energy-curable protective film, and is also used to form a hard protective film after curing.

[0224] Examples of energy-curable components (a) include polymers (a1) having energy-curable groups and a weight-average molecular weight of 80,000 to 2,000,000, and compounds (a2) having energy-curable groups and a molecular weight of 100 to 80,000. At least a portion of the polymer (a1) may be cross-linked by a cross-linking agent or may not be cross-linked.

[0225] (Polymers with energy-ray curable groups and a weight-average molecular weight of 80,000 to 2,000,000 (a1))

[0226] As a polymer (a1) having energy-curable groups and a weight-average molecular weight of 80,000 to 2,000,000, examples include acrylic resin (a1-1) formed by reacting an acrylic polymer (a11) and an energy-curable compound (a12). The acrylic polymer (a11) has functional groups that can react with groups present in other compounds, and the energy-curable compound (a12) has groups that react with the functional groups and energy-curable groups such as energy-curable double bonds.

[0227] Functional groups capable of reacting with groups found in other compounds include, for example, hydroxyl, carboxyl, amino, substituted amino (a group in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom), epoxy, etc. However, from the perspective of preventing circuit corrosion of workpieces or processed workpieces, the functional group is preferably a group other than a carboxyl group.

[0228] The functional group is preferably a hydroxyl group.

[0229] • Acrylic polymers with functional groups (a11)

[0230] As an example of the acrylic polymer (a11) having the functional group, a polymer can be formed by copolymerizing an acrylic monomer having the functional group with an acrylic monomer not having the functional group, or a polymer formed by further copolymerizing monomers other than acrylic monomers (non-acrylic monomers) in addition to these monomers.

[0231] Furthermore, the acrylic polymer (a11) can be a random copolymer or a block copolymer, and the polymerization method can also be a known method.

[0232] Examples of acrylic monomers having the aforementioned functional groups include hydroxyl-containing monomers, carboxyl-containing monomers, amino-containing monomers, substituted amino-containing monomers, and epoxy-containing monomers.

[0233] Examples of hydroxyl-containing monomers include hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, and other hydroxyalkyl methacrylates; and non-methacrylic unsaturated alcohols (unsaturated alcohols without a methacryloyl skeleton) such as vinyl alcohol and allyl alcohol.

[0234] Examples of the carboxyl-containing monomers include, for example, (meth)acrylic acid, crotonic acid, and other olefinically unsaturated monocarboxylic acids (monocarboxylic acids having olefinically unsaturated bonds); fumaric acid, itaconic acid, maleic acid, citraconic acid, and other olefinically unsaturated dicarboxylic acids (dicarboxylic acids having olefinically unsaturated bonds); anhydrides of the aforementioned olefinically unsaturated dicarboxylic acids; and carboxylalkyl esters of (meth)acrylic acid, such as 2-carboxyethyl methacrylate.

[0235] Preferably, the acrylic monomer having the aforementioned functional group is a hydroxyl-containing monomer.

[0236] The acrylic monomers having the functional groups constituting the acrylic polymer (a11) can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0237] Examples of acrylic monomers that do not possess the aforementioned functional groups include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, and so on. Alkyl esters, such as decyl methacrylate, undecyl methacrylate, dodecyl methacrylate (laurate methacrylate), tridecyl methacrylate, tetradecyl methacrylate (myristyl methacrylate), pentadecyl methacrylate, hexadecyl methacrylate (palmitoyl methacrylate), heptadecanyl methacrylate, and octadecyl methacrylate (stearic acid ester), are chain alkyl esters in which the alkyl group has a carbon atom number of 1 to 18.

[0238] In addition, examples of acrylic monomers that do not have the aforementioned functional groups include (meth)acrylates containing alkoxyalkyl groups such as (meth)acrylate methoxymethyl ester, (meth)acrylate methoxyethyl ester, (meth)acrylate ethoxymethyl ester, and (meth)acrylate ethoxyethyl ester; (meth)acrylates containing aromatic groups such as (meth)acrylate aryl esters such as (meth)acrylate phenyl ester; non-crosslinked (meth)acrylamide and its derivatives; and non-crosslinked (meth)acrylates containing tertiary amino groups such as (meth)acrylate N,N-dimethylaminoethyl ester and (meth)acrylate N,N-dimethylaminopropyl ester.

[0239] The acrylic monomers that do not have the functional groups constituting the acrylic polymer (a11) can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0240] Examples of non-acrylic acid monomers include, for example, olefins such as ethylene and norbornene; vinyl acetate; and styrene.

[0241] The non-acrylic monomers constituting the acrylic polymer (a11) may be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0242] In the acrylic polymer (a11), the ratio (content) of the structural units derived from the acrylic monomer having the aforementioned functional groups to the total amount of structural units constituting the polymer is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass, and particularly preferably 3 to 30% by mass. By setting the ratio within the above range, in the acrylic resin (a1-1) obtained by copolymerizing the acrylic polymer (a11) with the energy-curable compound (a12), the content of energy-curable groups can be easily adjusted to the preferred range to control the degree of curing of the protective film.

[0243] The acrylic polymer (a11) constituting the acrylic resin (a1-1) may be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0244] In the composition (IV-1), the ratio of the content of acrylic resin (a1-1) to the total content of the components other than the solvent (i.e., the ratio of the content of acrylic resin (a1-1) in the film for forming an energy-curable protective film to the total mass of the film) is preferably 1 to 70% by mass, more preferably 5 to 60% by mass, and particularly preferably 10 to 50% by mass.

[0245] • Energy-curing compounds (a12)

[0246] The energy-curable compound (a12) preferably has one or more groups selected from the group consisting of isocyanate groups, epoxy groups, and carboxyl groups as functional groups capable of reacting with the functional groups of the acrylic polymer (a11), and more preferably has an isocyanate group as the functional group. For example, when the energy-curable compound (a12) has an isocyanate group as the functional group, the isocyanate group readily reacts with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the functional group.

[0247] The number of energy-curing groups in one molecule of the energy-curing compound (a12) is not particularly limited; for example, appropriate selection can be made based on physical properties such as shrinkage required for the target protective film.

[0248] For example, the energy-curing compound (a12) preferably has 1 to 5 energy-curing groups in one molecule, more preferably 1 to 3 energy-curing groups.

[0249] Examples of energy-curable compounds (a12) include 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate.

[0250] Acryloyl monoisocyanate compounds are obtained by reacting diisocyanate compounds or polyisocyanate compounds with hydroxyethyl (meth)acrylate.

[0251] Acryloyl monoisocyanate compounds, etc., are obtained by reacting diisocyanate compounds or polyisocyanate compounds with polyol compounds and hydroxyethyl (meth)acrylate.

[0252] The energy-curable compound (a12) is preferably 2-methacryloyloxyethyl isocyanate.

[0253] The energy-curable compound (a12) constituting the acrylic resin (a1-1) may be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0254] In the acrylic resin (a1-1), the content of the energy-curable groups from the energy-curable compound (a12) relative to the content of the functional groups from the acrylic polymer (a11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. By setting the content ratio within the above range, the adhesive strength of the cured film for forming the energy-curable protective film is further increased. Furthermore, when the energy-curable compound (a12) is a monofunctional compound (having one of the aforementioned groups in one molecule), the upper limit of the content ratio is 100 mol%, but when the energy-curable compound (a12) is a polyfunctional compound (having two or more of the aforementioned groups in one molecule), the upper limit of the content ratio sometimes exceeds 100 mol%.

[0255] The weight-average molecular weight (Mw) of the polymer (a1) is preferably 100,000 to 2,000,000, more preferably 300,000 to 1,500,000.

[0256] The “weight-average molecular weight” refers to the weight-average molecular weight as previously stated.

[0257] When at least a portion of the polymer (a1) is crosslinked by a crosslinking agent, the polymer (a1) can be: a polymer that is polymerized from a monomer that is not one of the monomers described above as constituting the acrylic polymer (a11) and has a group that reacts with the crosslinking agent, and is crosslinked at the group that reacts with the crosslinking agent; or a polymer that is crosslinked at the group that reacts with the functional group from the energy-curable compound (a12).

[0258] The polymer (a1) contained in the composition (IV-1) and the film for forming the energy-curable protective film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0259] (Compounds with energy-ray-curing functional groups and molecular weights ranging from 100 to 80,000 (a2))

[0260] The energy-curing group in a compound (a2) having an energy-curing group and a molecular weight of 100 to 80,000 can be a group containing an energy-curing double bond, and preferred groups include (meth)acryloyl, vinyl, etc.

[0261] As long as the above conditions are met, the compound (a2) is not particularly limited, and examples include low molecular weight compounds with energy-curable groups, epoxy resins with energy-curable groups, and phenolic resins with energy-curable groups.

[0262] As a low molecular weight compound having an energy-curable group in compound (a2), examples include multifunctional monomers or oligomers, and preferably acrylate compounds having a (meth)acryloyl group.

[0263] Examples of such acrylate compounds include 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxydiethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloyloxypolypropoxy)phenyl]propane, tricyclodecanediethanol di(meth)acrylate, and 1,10-decanediol dimethacrylate. (Meth)acrylates, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloyloxyethoxy)phenyl]propane, neopentyl glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, 2-hydroxy-1,3-di(meth)acryloyloxypropane and other difunctional (meth)acrylates;

[0264] Tris(2-(meth)acryloyloxyethyl)isocyanurate, ε-caprolactone-modified tris(2-(meth)acryloyloxyethyl)isocyanurate, ethoxylated glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, dipentaerythritol hexa(meth)acrylate and other multifunctional (meth)acrylates;

[0265] Multifunctional (meth)acrylate oligomers, such as urethane (meth)acrylate oligomers.

[0266] As the epoxy resin having energy-curable groups or the phenolic resin having energy-curable groups in the compound (a2), for example, the resin described in paragraph 0043 of Japanese Patent Application Publication No. 2013-194102 may be used. The above-mentioned resins also belong to the resins constituting the thermosetting components described below, but are regarded as the compound (a2) in this invention.

[0267] The weight-average molecular weight of the compound (a2) is preferably 100 to 30,000, more preferably 300 to 10,000.

[0268] The compound (a2) contained in the composition (IV-1) and the film for forming an energy-curable protective film can be only one or more. When there are more than two compounds, their combination and ratio can be arbitrarily selected.

[0269] [Polymers without energy-curing groups (b)]

[0270] When the composition (IV-1) and the film for forming an energy-curable protective film contain the compound (a2) as the energy-curable component (a), it is preferable to further contain a polymer (b) that does not have an energy-curable group.

[0271] At least a portion of the polymer (b) may or may not be cross-linked by a cross-linking agent.

[0272] Examples of polymers (b) that do not have energy-curable groups include acrylic polymers, phenoxy resins, urethane resins, polyesters, rubber resins, and urethane resins.

[0273] Wherein, the polymer (b) is preferably an acrylic polymer (hereinafter, sometimes abbreviated as "acrylic polymer (b-1)").

[0274] The acrylic polymer (b-1) can be any known composition, such as a homopolymer of one acrylic monomer, a copolymer of two or more acrylic monomers, or a copolymer of one or more acrylic monomers with one or more monomers other than acrylic monomers (non-acrylic monomers).

[0275] Examples of acrylic monomers constituting the acrylic polymer (b-1) include alkyl (meth)acrylates, (meth)acrylates having a cyclic backbone, (meth)acrylates containing glycidyl groups, (meth)acrylates containing hydroxyl groups, and (meth)acrylates containing substituted amino groups. Here, "substituted amino group" refers to the substituted amino group described above.

[0276] As an example of the (meth)acrylate alkyl ester, an example of an (meth)acrylate alkyl ester that is the same as the acrylic monomer (such as (meth)acrylate alkyl esters in which the alkyl group constituting the acrylic polymer (a11) described above does not have the aforementioned functional group)

[0277] Examples of (meth)acrylates having a cyclic skeleton include isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, and other cycloalkyl (meth)acrylates.

[0278] (Meth)benzyl acrylate and other (meth)acrylate aralkyl esters;

[0279] (Meth)acrylate dicyclopentenyl ester and other (meth)acrylate cycloalkenyl esters;

[0280] (Meth)acrylate dicyclopentenyloxyethyl ester, etc., (meth)acrylate cyclopentenyloxyalkyl ester, etc.

[0281] Examples of glycidyl acrylates containing glycidyl groups include glycidyl acrylate.

[0282] Examples of hydroxyl-containing (meth)acrylates 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.

[0283] Examples of substituted amino-containing (meth)acrylates include N-methylaminoethyl (meth)acrylate.

[0284] Examples of non-acrylic monomers constituting the acrylic polymer (b-1) include, for example, olefins such as ethylene and norbornene; vinyl acetate; styrene, etc.

[0285] As a polymer (b) that is at least partially crosslinked by a crosslinking agent and does not have energy-curable groups, for example, a polymer obtained by reacting the reactive functional groups in the polymer (b) with a crosslinking agent can be listed.

[0286] The reactive functional group can be selected appropriately based on the type of crosslinking agent, and there are no particular limitations. For example, when the crosslinking agent is a polyisocyanate compound, hydroxyl, carboxyl, and amino groups can be listed as reactive functional groups, among which hydroxyl groups, which have high reactivity with isocyanate groups, are preferred. Furthermore, when the crosslinking agent is an epoxy compound, carboxyl, amino, and amide groups can be listed as reactive functional groups, among which carboxyl groups, which have high reactivity with epoxy groups, are preferred. However, from the perspective of preventing circuit corrosion of the workpiece or the processed workpiece, the reactive functional group is preferably a group other than a carboxyl group.

[0287] As a polymer (b) having the aforementioned reactive functional group but lacking an energy-curable group, examples include polymers obtained by polymerizing monomers having at least the aforementioned reactive functional group. When it is an acrylic polymer (b-1), any one or two of the acrylic monomers and non-acrylic monomers listed as monomers constituting the acrylic polymer (b-1) may be used as examples. As a polymer (b) having a hydroxyl group as a reactive functional group, examples include polymers obtained by polymerizing hydroxyl-containing (meth)acrylates. In addition, polymers obtained by polymerizing monomers in which one or more hydrogen atoms of the previously listed acrylic monomers or non-acrylic monomers are replaced by the aforementioned reactive functional group.

[0288] In the polymer (b) having reactive functional groups, the ratio (content) of the amount of structural units derived from monomers having reactive functional groups to the total amount of structural units constituting the polymer is preferably 1 to 20% by mass, more preferably 2 to 10% by mass. By setting the ratio to the above range, the degree of crosslinking in the polymer (b) becomes a more preferred range.

[0289] From the point of improving the film-forming properties of composition (IV-1), the weight-average molecular weight (Mw) of the polymer (b) without energy-curable groups is preferably 10,000 to 2,000,000, more preferably 100,000 to 1,500,000. Herein, "weight-average molecular weight" refers to the weight-average molecular weight described above.

[0290] The polymer (b) contained in the composition (IV-1) and the film for forming the energy-curable protective film without energy-curable groups can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0291] As composition (IV-1), examples include compositions containing either or both of the polymer (a1) and the compound (a2). Furthermore, when composition (IV-1) contains the compound (a2), it is preferable to further contain a polymer (b) without energy-curable groups, and in this case, it is even more preferable to contain the polymer (a1). Alternatively, composition (IV-1) may not contain the compound (a2) but may simultaneously contain the polymer (a1) and the polymer (b) without energy-curable groups.

[0292] When the composition (IV-1) contains the polymer (a1), the compound (a2), and the polymer (b) without energy-curable groups, the content of the compound (a2) in the composition (IV-1) is preferably 10 to 400 parts by mass, more preferably 30 to 350 parts by mass, relative to the total content of the polymer (a1) and the polymer (b) without energy-curable groups of 100 parts by mass.

[0293] In composition (IV-1), the ratio of the total content of the energy-curable component (a) and the polymer (b) without energy-curable groups to the total content of components other than the solvent (i.e., the ratio of the total content of the energy-curable component (a) and the polymer (b) without energy-curable groups in the film for forming an energy-curable protective film to the total mass of the film) is preferably 5 to 90% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass. By setting the ratio of the energy-curable component content to the above range, the energy-curability of the film for forming an energy-curable protective film is improved.

[0294] In addition to the energy-curable component described above, the composition (IV-1) may, depending on the purpose, contain one or more of the following: thermosetting components, fillers, coupling agents, crosslinking agents, photopolymerization initiators, colorants, and general additives.

[0295] The thermosetting components, fillers, coupling agents, crosslinking agents, photopolymerization initiators, colorants, and general additives in composition (IV-1) may include the same components as those in composition (III-1), namely thermosetting component (B), filler (D), coupling agent (E), crosslinking agent (F), photopolymerization initiator (H), colorant (I), and general additive (J).

[0296] For example, by using a composition (IV-1) containing the energy-curable component and the thermosetting component, the adhesion of the energy-curable protective film to the substrate is improved by heating, and the strength of the protective film formed by the energy-curable protective film is also improved.

[0297] Furthermore, by using the composition (IV-1) containing the energy-curable component and the colorant, the energy-curable protective film formed exhibits the same effect as the thermosetting protective film containing the colorant (I) described above.

[0298] In the composition (IV-1), the thermosetting component, filler, coupling agent, crosslinking agent, photopolymerization initiator, colorant and general additive can each be used individually or in combination with two or more. When two or more are used simultaneously, their combination and ratio can be arbitrarily selected.

[0299] The contents of the thermosetting components, fillers, coupling agents, crosslinking agents, photopolymerization initiators, colorants, and general additives in the composition (IV-1) can be adjusted appropriately according to the purpose, and there are no particular limitations.

[0300] Since the workability of the composition (IV-1) is improved by dilution, it is preferable to further contain a solvent.

[0301] As a solvent contained in composition (IV-1), for example, solvents that are the same as those in composition (III-1) can be listed.

[0302] The composition (IV-1) may contain only one solvent or two or more solvents.

[0303] The solvent content of composition (IV-1) is not particularly limited, for example, it can be appropriately selected according to the types of components other than the solvent.

[0304] <Preparation Method of Composition for Forming Energy-Based Curable Protective Films>

[0305] The composition (IV-1) for forming an energy-curable protective film can be obtained by incorporating the components used to constitute the composition.

[0306] Apart from the difference in the types of admixtures, the composition for forming an energy-curable protective film can be prepared, for example, by the same method as the adhesive composition described above.

[0307] ◎ Non-curing protective film forming film

[0308] As a preferred non-curing protective film forming film, examples include films containing thermoplastic resin and filler materials.

[0309] <Composition for forming non-curing protective film (V-1)>

[0310] Preferred non-curing protective film forming compositions include, for example, a non-curing protective film forming composition (V-1) containing the thermoplastic resin and filler material (sometimes simply abbreviated as "composition (V-1)" in this specification).

[0311] [Thermoplastic resin]

[0312] The thermoplastic resin is not particularly limited.

[0313] More specifically, the thermoplastic resin mentioned above can be an example of a non-curing resin such as acrylic resin, polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, or polystyrene, which are included as components of composition (III-1) as described above.

[0314] The thermoplastic resin contained in the composition (V-1) and the non-curing protective film forming film may be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0315] In composition (V-1), the ratio of the content of the thermoplastic resin to the total content of the components other than the solvent (i.e., the ratio of the content of the thermoplastic resin in the non-curing protective film forming film to the total mass of the non-curing protective film forming film) is preferably 25 to 75 by mass.

[0316] [Filling Material]

[0317] The non-curing protective film forming film containing filler material has the same effect as the thermosetting protective film forming film containing filler material (D).

[0318] As filler materials contained in composition (V-1) and the non-curing protective film forming film, the same filler materials as those contained in composition (III-1) and the thermosetting protective film forming film (D) can be listed.

[0319] The filler material contained in the composition (V-1) and the non-curing protective film forming film can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0320] In composition (V-1), the ratio of the filler content to the total content of all components except the solvent (i.e., the ratio of the filler content in the non-curing protective film forming film to the total mass of the non-curing protective film forming film) is preferably 25% to 75% by mass. By setting the ratio to the above range, it becomes easier to adjust the coefficient of thermal expansion of the non-curing protective film forming film (i.e., the protective film), as when using composition (III-1).

[0321] In addition to the thermoplastic resin and filler material, the composition (V-1) may contain other components depending on the purpose.

[0322] The other ingredients are not particularly limited and can be selected arbitrarily according to the purpose.

[0323] For example, by using a composition (V-1) containing the thermoplastic resin and the colorant, the resulting non-curing protective film forming film (in other words, the protective film) exhibits the same effect as the thermosetting protective film forming film previously described containing the colorant (I).

[0324] In the composition (V-1), the other components may be used alone or in combination with two or more components. When two or more components are used simultaneously, their combination and ratio may be arbitrarily selected.

[0325] The content of the other components in composition (V-1) may be adjusted appropriately according to the purpose, and there are no particular limitations.

[0326] Since the workability of the composition (V-1) is improved by dilution, it is preferable to further contain a solvent.

[0327] As a solvent contained in composition (V-1), for example, solvents that are the same as those in composition (III-1) described above can be listed.

[0328] The composition (V-1) may contain only one solvent or two or more solvents.

[0329] The solvent content of composition (V-1) is not particularly limited; for example, it can be appropriately selected according to the types of components other than the solvent.

[0330] <Preparation Method of Composition for Forming Non-curing Protective Film>

[0331] Compositions such as Composition (V-1) for forming non-curing protective films can be obtained by incorporating the components used to constitute the composition.

[0332] Apart from the difference in the types of admixtures, the composition for forming a non-curing protective film can be prepared, for example, by the same method as the adhesive composition described above.

[0333] So far, the description has mainly focused on the case where a protective film forming composite sheet is formed by using both the protective film forming film and the support sheet. However, the protective film forming film may also be used without the support sheet, and in a state where it does not form a protective film forming composite sheet.

[0334] For example, after attaching a protective film (which does not constitute a composite sheet for forming a protective film) to any position on a workpiece, directly irradiating the protective film with a laser from the outside of the film or protective film can effectively print text on it. This printing process will be described in detail later.

[0335] The printing suitability of printing directly onto the protective film without a support sheet is generally equal to or greater than that of printing through a support sheet.

[0336] When the protective film forming membrane is used in a manner that does not constitute a protective film forming composite sheet, the protective film forming membrane may be the same as the protective film forming membrane used when it constitutes a protective film forming composite sheet.

[0337] 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 can be provided on the side of the protective film forming film opposite to the side attached to the workpiece. In this case, it is preferable to remove the release film before laser irradiation.

[0338] As an example of a preferred protective film forming film of this embodiment, the following can be cited:

[0339] A thermosetting protective film forming film comprising a polymer component (A), a thermosetting component (B), and a colorant (I),

[0340] The polymer component (A) is an acrylic resin.

[0341] The thermosetting component (B) is an epoxy thermosetting resin formed from epoxy resin (B1) and thermosetting agent (B2).

[0342] Another example of a preferred protective film forming membrane in this embodiment can be listed as follows:

[0343] A thermosetting protective film forming film comprising a polymer component (A), a thermosetting component (B), and a colorant (I),

[0344] The polymer component (A) is a polymer of alkyl (meth)acrylate and hydroxyl-containing (meth)acrylate, wherein the alkyl group constituting the alkyl acrylate has a chain structure with 1 to 18 carbon atoms.

[0345] The thermosetting component (B) is an epoxy thermosetting resin formed from epoxy resin (B1) and thermosetting agent (B2).

[0346] The epoxy resin (B1) is selected from one or more of the group consisting of bisphenol A type epoxy resin, dicyclopentadiene type epoxy resin, and o-cresol phenolic varnish epoxy resin.

[0347] The thermosetting agent (B2) is an amine curing agent containing amino groups.

[0348] The colorant (I) is one or more selected from the group consisting of organic pigments and organic dyes.

[0349] ◇ Composite sheet for protective film formation

[0350] A protective film forming composite sheet according to one embodiment of the present invention includes a support sheet and a protective film forming film disposed on one surface of the support sheet. The support sheet has a light transmittance (355nm) of 20% or more, and the protective film forming film is the protective film forming film of the present invention described above (i.e., the protective film forming film has a light transmittance (355nm) of 60% or less).

[0351] As described above, the protective film forming film in the protective film forming composite sheet of this embodiment is either curable or non-curable.

[0352] The protective film forming composite sheet can be used to: irradiate the protective film forming film or protective film in the protective film forming composite sheet with a laser from the outside of the support sheet side of the protective film forming composite sheet, thereby printing words on the protective film forming film or protective film.

[0353] Because the support sheet of the protective film forming composite sheet in this embodiment has high light transmittance (355nm) and the protective film forming film has low light transmittance (355nm), it is possible to print text on the protective film forming film or the protective film even when irradiated with a laser with a shorter wavelength than conventionally (e.g., a wavelength of 355nm). Furthermore, the text can be clearly identified through the support sheet.

[0354] The support plate will be described in detail below.

[0355] ◎Supporting plate

[0356] The support sheet has a transmittance of more than 20% for light with a wavelength of 355nm (light (355nm)).

[0357] The support sheet can be used to fix a workpiece having a protective film or protective film formed on any position. For example, when the workpiece is a semiconductor wafer, the support sheet can be used to fix a semiconductor wafer having a protective film or protective film formed on its back side.

[0358] Examples of support sheets include: a support sheet having a substrate and an adhesive layer disposed on one side of the substrate; a support sheet made of a substrate; a support sheet having a substrate, an adhesive layer disposed on one side of the substrate, and an intermediate layer disposed on the side of the adhesive layer opposite to the substrate side; and a support sheet having a substrate and an intermediate layer disposed on one side of the substrate. When the support sheet has an adhesive layer, in the composite sheet for forming a protective film described later, the adhesive layer is disposed between the substrate and the protective film forming film.

[0359] When a support sheet with a substrate and an adhesive layer is used, the adhesion or tightness between the support sheet and the protective film forming film can be easily adjusted in the composite sheet for forming the protective film.

[0360] When a support sheet made of a substrate is used, a composite sheet for forming a protective film can be manufactured at low cost.

[0361] When a support sheet comprising a substrate, an adhesive layer, and an intermediate layer is used, new functions can be imparted to the support sheet or the composite sheet for forming the protective film. Furthermore, compared to the case with the adhesive layer described above, the adhesion or bonding strength between the support sheet and the protective film for forming can be adjusted more easily.

[0362] The support sheet has high light transmittance (355nm). Therefore, by irradiating the protective film forming film or the protective film in the protective film forming composite sheet with a laser of a shorter wavelength than conventional, such as 355nm, from the outside of the support sheet side of the protective film forming composite sheet through the support sheet, it is possible to effectively imprint text on the protective film forming film or the protective film. Moreover, the imprinted text can be clearly identified from the outside of the support sheet side of the protective film forming composite sheet through the support sheet.

[0363] The transmittance of the support sheet to light (355nm) is preferably 23% or more, for example, it can be any range of 40% or more, 50% or more, 60% or more, 70% or more, and 80% or more. By making the transmittance of the support sheet above the lower limit value, the printability and print visibility of the film for forming the protective film or the protective film are further improved.

[0364] There is no particular limit to the upper limit of the transmittance of the support sheet to light (355nm), for example, it can be 100%. For example, it is easier to manufacture a support sheet with a transmittance of 97% or less.

[0365] The transmittance of the support sheet to light (355nm) can be appropriately adjusted within a range set by any combination of the aforementioned lower and upper limits. For example, in one embodiment, the transmittance of the support sheet is preferably 20-97%, more preferably 23-97%, and can be any range from 40-97%, 50-97%, 60-97%, 70-97%, and 80-97%. However, these ranges are merely examples of the transmittance of the support sheet.

[0366] ○ Substrate

[0367] The substrate is in sheet or film form and has light transmittance (355nm).

[0368] Various resins can be listed as constituent materials of the substrate.

[0369] Examples of resins 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); polyacrylates; and polycarbonate (PC).

[0370] The resin constituting the substrate can be a single type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0371] The substrate can consist of one layer (single layer) or multiple layers (two or more layers). When it consists of multiple layers, these multiple layers can be the same as each other or different from each other, and there are no particular restrictions on the combination of these multiple layers.

[0372] The thickness of the substrate is preferably 40–300 μm, more preferably 40–100 μm. By making the substrate thickness within the above range, the flexibility and adhesion to the workpiece or workpiece processed by the composite sheet for forming the protective film are further improved.

[0373] The “thickness of the substrate” refers to the overall thickness of the substrate. For example, the thickness of a substrate composed of multiple layers refers to the total thickness of all the layers that make up the substrate.

[0374] The substrate is preferably a substrate with high thickness accuracy, that is, a substrate in which thickness unevenness is suppressed in any part. Among the above-mentioned constituent materials, materials that can be used to constitute the above-mentioned substrate with high thickness accuracy include, for example, polyolefins and polyethylene terephthalate.

[0375] In addition to the main constituent materials such as the resin, the substrate may also contain various known additives such as fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, and softeners (plasticizers).

[0376] For example, by adjusting the presence or absence of filler or colorant in the substrate, or the content of filler or colorant in the substrate, the transmittance of the substrate to light (355nm) can be easily adjusted.

[0377] As a substrate, it is preferable to have a substrate that does not contain, or contains in small amounts of, components that absorb light (355 nm). Examples of components that absorb light (355 nm) include compounds with aromatic cyclic groups, such as resins or colorants that have a benzene ring skeleton (i.e., groups with a structure formed by removing 1 to 6 hydrogen atoms from benzene).

[0378] The substrate can have adhesiveness on at least one side by containing a specific range of components (e.g., resins, etc.).

[0379] Regarding the optical properties of the substrate, it is sufficient as long as the support sheet meets the transmittance of light (355nm) as described above.

[0380] For example, as described above, sometimes the support sheet is made of only the substrate, so the transmittance of the substrate to light (355nm) can be the same as that of the support sheet illustrated above to light (355nm).

[0381] Furthermore, for the same reasons as the aforementioned support sheet's transmittance to light (355nm), the transmittance of the substrate to light (355nm) can be, for example, any range of 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, and 90% or more.

[0382] Furthermore, for the same reasons as with the aforementioned support sheet regarding its transmittance to light (355nm), there is no particular limitation on the upper limit of the substrate's transmittance to light (355nm), which can be, for example, 100%. For instance, it is easier to manufacture or obtain a substrate with a transmittance of 97% or less.

[0383] Furthermore, the transmittance of the substrate to light (355 nm) can be appropriately adjusted within a range set by any combination of the aforementioned lower and upper limits. For example, in one embodiment, the transmittance of the substrate can be any range of 40–97%, 50–97%, 60–97%, 70–97%, 80–97%, and 90–97%. However, these ranges are merely one example of the transmittance of the substrate.

[0384] To improve the adhesion between the substrate and the layers disposed on the substrate (e.g., adhesive layers, protective film forming films, etc.), surface treatments such as sandblasting, solvent-based treatments, corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone-ultraviolet irradiation treatment, flame treatment, chromic acid treatment, and hot air treatment can be applied. Furthermore, a primer treatment can be applied to the surface of the substrate.

[0385] In addition, the substrate may have the following layers: an antistatic coating layer; a layer that prevents the substrate from adhering to other sheets or the substrate from adhering to the adsorption stage when the composite sheet for forming the protective film is stacked and stored.

[0386] In addition, the substrate may also have a release layer on its surface.

[0387] The substrate can be manufactured using known methods. For example, a resin-containing substrate can be manufactured by molding a resin composition containing said resin.

[0388] ○Adhesive layer

[0389] The adhesive layer is in sheet or film form and has light transmittance (355nm).

[0390] The adhesive layer contains an adhesive.

[0391] Examples of adhesives include acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyethylene ethers, polycarbonates, ester resins, and other adhesive resins, with acrylic resins being preferred.

[0392] Furthermore, in this specification, "adhesive resin" includes both adhesive resins and bonding resins. For example, the adhesive resin includes not only resins that are adhesive in themselves, but also resins that exhibit adhesiveness when used in conjunction with other components such as additives, or resins that exhibit bondingness due to the presence of triggers such as heat or water.

[0393] The adhesive layer can consist of one layer (single layer) or multiple layers (two or more layers). When it consists of multiple layers, these multiple layers can be the same as each other or different from each other, and there are no particular restrictions on the combination of these multiple layers.

[0394] The thickness of the adhesive layer is preferably 1 to 14 μm, more preferably 2 to 12 μm, and for example, 3 to 8 μm. By making the thickness of the adhesive layer above or below the lower limit, the effect of providing the adhesive layer can be obtained more significantly. By making the thickness of the adhesive layer below or below the upper limit, it is possible to print the text on the protective film forming film or the protective film in the protective film forming composite sheet more effectively. Furthermore, the text can be more clearly identified from the outside of the support sheet side of the protective film forming composite sheet, with the support sheet in between.

[0395] The "thickness of the adhesive layer" refers to the overall thickness of the adhesive layer. For example, the thickness of an adhesive layer consisting of multiple layers refers to the total thickness of all the layers that make up the adhesive layer.

[0396] As for the optical properties of the adhesive layer, it is sufficient as long as the support sheet meets the transmittance condition for light (355nm) described above.

[0397] The adhesive layer can be formed using either an energy-curable adhesive or a non-energy-curable adhesive. That is, the adhesive layer can be either energy-curable or non-energy-curable. Energy-curable adhesive layers allow for easy adjustment of their properties before and after curing. For example, before picking up semiconductor chips with protective films or semiconductor chips with protective film forming films (described later), these semiconductor chips can be picked up more easily by curing the energy-curable adhesive layer.

[0398] Adhesive Compositions

[0399] The adhesive layer can be formed using an adhesive composition containing an adhesive. For example, the adhesive composition is applied to the surface to which the adhesive layer is to be formed and dried as needed, thereby forming the adhesive layer at the target location. The proportions of the non-vaporizable components in the adhesive composition are generally the same as the proportions of the components in the adhesive layer.

[0400] The coating of the adhesive composition can be carried out, for example, by the same method as that used for coating protective film formation of the above-described composition.

[0401] There are no particular limitations on the drying conditions of the adhesive composition, but when the adhesive composition contains the solvent described below, heat drying is preferred. For example, adhesive compositions containing solvent are preferably dried at 70–130°C for 10 seconds to 5 minutes.

[0402] When forming an adhesive layer on a substrate, for example, the adhesive layer can be laminated onto the substrate simply by applying an adhesive composition to the substrate and drying it as needed. Alternatively, when forming an adhesive layer on a substrate, for example, an adhesive composition can be applied to a release film and dried as needed, thereby first forming an adhesive layer on the release film. The exposed surface of this adhesive layer is then bonded to a surface of the substrate, thereby laminating the adhesive layer onto the substrate. In this case, the release film can be removed at any time during the manufacturing process or use of the composite sheet for forming the protective film.

[0403] When the adhesive layer is energy-curable, examples of energy-curable adhesive compositions include: an adhesive composition (I-1) containing a non-energy-curable adhesive resin (I-1a) (hereinafter sometimes abbreviated as "adhesive resin (I-1a)") and an energy-curable compound; an adhesive composition (I-2) containing an energy-curable adhesive resin (I-2a) (hereinafter sometimes abbreviated as "adhesive resin (I-2a)") with unsaturated groups introduced into the side chains of the adhesive resin (I-1a); and an adhesive composition (I-3) containing the adhesive resin (I-2a) and an energy-curable compound.

[0404] When the adhesive layer is non-energy-curable, examples of non-energy-curable adhesive compositions include adhesive compositions (I-4) containing the adhesive resin (I-1a).

[0405] [Adhesive resin (I-1a)]

[0406] The adhesive resin (I-1a) in the adhesive compositions (I-1), (I-2), (I-3), and (I-4) (hereinafter, these adhesive compositions are collectively referred to as "adhesive compositions (I-1) to (I-4)") is preferably an acrylic resin.

[0407] Examples of acrylic resins include acrylic polymers having at least structural units derived from (meth)acrylate alkyl esters.

[0408] As an example of the alkyl methacrylate, an alkyl methacrylate in which the alkyl group constituting the alkyl ester has 1 to 20 carbon atoms is provided, wherein the alkyl group is preferably linear or branched.

[0409] In addition to structural units derived from alkyl (meth)acrylates, the acrylic polymer preferably further comprises structural units derived from functionalized monomers.

[0410] Examples of functionalized monomers include those that form crosslinking initiation points by reacting the functional group with the crosslinking agent described below, or those that react the functional group with the unsaturated groups in the unsaturated group compounds described below, thereby introducing unsaturated groups into the side chains of acrylic polymers.

[0411] Examples of functional group-containing monomers include hydroxyl-containing monomers, carboxyl-containing monomers, amino-containing monomers, and epoxy-containing monomers.

[0412] In addition to structural units derived from alkyl (meth)acrylates and structural units derived from functionalized monomers, the acrylic polymer may further have structural units derived from other monomers.

[0413] The other monomers are not particularly limited as long as they can copolymerize with alkyl methacrylates, etc.

[0414] Other monomers mentioned include, for example, styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

[0415] In the adhesive compositions (I-1) to (I-4), the acrylic polymer or the acrylic resin may have only one structural unit or two or more structural units. When there are two or more structural units, their combination and ratio can be arbitrarily selected.

[0416] In the acrylic polymer, the content of structural units derived from functional group-containing monomers is preferably 1 to 35% by mass relative to the total amount of structural units.

[0417] The adhesive composition (I-1) or adhesive composition (I-4) may contain only one type of adhesive resin (I-1a) or two or more types of adhesive resin. When there are two or more types of adhesive resin, the combination and ratio of them can be arbitrarily selected.

[0418] In the adhesive composition (I-1) or adhesive composition (I-4), the content of adhesive resin (I-1a) relative to the total mass of the adhesive composition (I-1) or adhesive composition (I-4) is preferably 5 to 99 by mass.

[0419] [Adhesive resin (I-2a)]

[0420] The adhesive resin (I-2a) in the adhesive compositions (I-2) and (I-3) can be obtained, for example, by reacting the functional groups in the adhesive resin (I-1a) with a compound containing unsaturated groups having energy-ray polymerizable unsaturated groups.

[0421] In addition to the energy-ray polymerizable unsaturated groups, the compound containing unsaturated groups further has groups that can bond with the adhesive resin (I-1a) by reacting with functional groups in the adhesive resin (I-1a).

[0422] Examples of polymerizable unsaturated groups that can be used as energy-ray polymerizable groups include (meth)acryloyl, vinyl (ethene), allyl (2-propenyl), etc., with (meth)acryloyl being preferred.

[0423] Examples of functional groups that can bond with the functional groups in the adhesive resin (I-1a) include isocyanate groups and glycidyl groups that can bond with hydroxyl or amino groups, as well as hydroxyl and amino groups that can bond with carboxyl or epoxy groups.

[0424] Examples of compounds containing unsaturated groups include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and (meth)acrylate glycidyl ester.

[0425] The adhesive composition (I-2) or (I-3) may contain only one type of adhesive resin (I-2a) or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0426] In adhesive compositions (I-2) or (I-3), the content of adhesive resin (I-2a) relative to the total mass of adhesive compositions (I-2) or (I-3) is preferably 5 to 99% by mass.

[0427] [Energy-cured compounds]

[0428] As the energy-curable compounds in the adhesive compositions (I-1) and (I-3), examples include monomers or oligomers having energy-curable unsaturated groups that can be cured by irradiation with energy rays.

[0429] In energy-curable compounds, monomers include, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol (meth)acrylate, and other poly(meth)acrylates; urethane (meth)acrylate; polyester (meth)acrylate; polyether (meth)acrylate; epoxy (meth)acrylate, etc.

[0430] In energy-curable compounds, oligomers, for example, can be formed by polymerizing the monomers exemplified above.

[0431] The adhesive composition (I-1) or (I-3) may contain only one or more energy-curable compounds, and when there are more than two, their combination and ratio can be arbitrarily selected.

[0432] In the adhesive composition (I-1), the content of the energy-curable compound relative to the total mass of the adhesive composition (I-1) is preferably 1 to 95% by mass.

[0433] In the adhesive composition (I-3), the content of the energy-curable compound is preferably 0.01 to 300 parts by mass relative to 100 parts by mass of the adhesive resin (I-2a).

[0434] [Cross-linking agent]

[0435] When the acrylic polymer, in addition to having structural units from alkyl methacrylates, is used as an adhesive resin (I-1a), the adhesive composition (I-1) or (I-4) preferably further contains a crosslinking agent.

[0436] Furthermore, for example, when the acrylic polymer having the same structural units from functionalized monomers as the adhesive resin (I-1a) is used as the adhesive resin (I-2a), the adhesive composition (I-2) or (I-3) may further contain a crosslinking agent.

[0437] The crosslinking agent, for example, reacts with the functional groups to crosslink the adhesive resins (I-1a) with each other or the adhesive resins (I-2a) with each other.

[0438] Examples of crosslinking agents include isocyanate crosslinking agents (crosslinking agents with isocyanate groups) such as toluene diisocyanate, hexamethylene diisocyanate, phenyl diisocyanate, and adducts of these diisocyanates; epoxy crosslinking agents (crosslinking agents with glycidyl groups) such as ethylene glycol glycidyl ether; aziridinium crosslinking agents (crosslinking agents with aziridinium groups) such as hexa[1-(2-methyl)-aziridinyl]triphosphatriazine; metal chelate crosslinking agents (crosslinking agents with metal chelate structures) such as aluminum chelates; and isocyanurate crosslinking agents (crosslinking agents with isocyanuric acid backbones).

[0439] The adhesive composition (I-1), (I-2) or (I-4) may contain only one crosslinking agent or two or more crosslinking agents. When there are two or more crosslinking agents, their combination and ratio can be arbitrarily selected.

[0440] In the adhesive composition (I-1) or (I-4), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass relative to 100 parts by mass of the adhesive resin (I-1a), for example, it can be any range of 0.01 to 35 parts by mass and 0.01 to 20 parts by mass.

[0441] In the 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 adhesive resin (I-2a), for example, any range of 0.01 to 35 parts by mass, 0.01 to 20 parts by mass, and 0.01 to 10 parts by mass.

[0442] [Photopolymerization initiator]

[0443] The adhesive compositions (I-1), (I-2), and (I-3) (hereinafter collectively referred to as "adhesive compositions (I-1) to (I-3)") may further contain a photopolymerization initiator. Even when the adhesive compositions (I-1) to (I-3) containing the photopolymerization initiator are irradiated with low-energy rays such as ultraviolet light, the curing reaction proceeds fully.

[0444] Examples of photopolymerization initiators include benzoin compounds such as 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 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropanoyl)benzyl)phenyl)-2-methylpropane-1-one; and phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6... - Acylphosphine oxide compounds such as trimethylbenzoyl diphenylphosphine oxide; sulfides such as benzylphenyl sulfide and tetramethylthiuram monosulfide; α-keto alcohol compounds such as 1-hydroxycyclohexylphenyl ketone; azo compounds such as azobisisobutyronitrile; diacetic compounds such as diaceticotrope; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as butanedione; benzoyl; dibenzoyl; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone.

[0445] In addition, photosensitizers such as amines can also be used as photopolymerization initiators.

[0446] The photopolymerization initiator contained in the adhesive compositions (I-1) to (I-3) can be only one type or two or more types. When there are two or more types, their combination and ratio can be arbitrarily selected.

[0447] In the 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 energy-curable compound.

[0448] In the adhesive composition (I-2), the content of photopolymerization initiator is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of adhesive resin (I-2a), for example, it can be any range of 0.01 to 10 parts by mass and 0.01 to 5 parts by mass.

[0449] In the 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 adhesive resin (I-2a) and the energy-curable compound.

[0450] [Other Additives]

[0451] Without impairing the effects of the present invention, the adhesive compositions (I-1) to (I-4) may contain other additives that are not among the above-mentioned components.

[0452] Other additives mentioned above include, for example, well-known additives such as antistatic agents, antioxidants, softeners (plasticizers), fillers (fillers), rust inhibitors, colorants (pigments, dyes), sensitizers, thickeners, reaction delayers, and crosslinking promoters (catalysts).

[0453] Furthermore, a reaction delay agent refers to an additive that, for example, inhibits unintended crosslinking reactions in the adhesive compositions (I-1) to (I-4) during storage by means of a catalyst incorporated into them. Examples of reaction delay agents include those that form chelate complexes using chelates against a catalyst; more specifically, reaction delay agents having two or more carbonyl groups (-C(=O)-) in one molecule can be listed.

[0454] The adhesive compositions (I-1) to (I-4) may contain only one other additive or two or more additives. When there are two or more additives, their combination and ratio can be arbitrarily selected.

[0455] The content of other additives in the adhesive compositions (I-1) to (I-4) is not particularly limited, and can be appropriately selected according to their types.

[0456] [solvent]

[0457] The adhesive compositions (I-1) to (I-4) may contain solvents. By including solvents in the adhesive compositions (I-1) to (I-4), the coating suitability for the target surface is improved.

[0458] The solvent is preferably an organic solvent. Examples of organic solvents 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.

[0459] The adhesive compositions (I-1) to (I-4) may contain only one solvent or two or more solvents. When there are two or more solvents, their combination and ratio can be arbitrarily selected.

[0460] The solvent content in the adhesive compositions (I-1) to (I-4) is not particularly limited, as long as it is adjusted appropriately.

[0461] Preferably, the adhesive layer and adhesive composition do not contain, for example, any component that absorbs light (355 nm), or contain only a small amount of such component. Examples of components that absorb light (355 nm) include those found in the substrate described above.

[0462] Preparation Method of Adhesive Composition

[0463] The adhesive compositions (I-1) to (I-4) can be obtained by incorporating the adhesive and other components other than the adhesive as required to form the adhesive composition.

[0464] There is no particular restriction on the order of addition when mixing the components, and more than two components can be added at the same time.

[0465] When blending, there are no particular limitations on the method of mixing the components. You may choose an appropriate method from the following known methods: mixing by rotating a stir bar or stirring blade; mixing by using a mixer; mixing by applying ultrasound, etc.

[0466] As long as the individual blended components do not deteriorate, there are no particular limitations on the temperature and time when adding and mixing the components; they can be adjusted appropriately. However, the preferred temperature is 15–30°C.

[0467] ○ Intermediate layer

[0468] The intermediate layer is sheet-like or film-like and has light transmittance (355nm).

[0469] The intermediate layer is disposed between the adhesive layer and the protective film forming film in the composite sheet for forming the protective film.

[0470] The type of intermediate layer can be chosen arbitrarily according to the purpose, without any particular limitation.

[0471] As for the optical properties of the intermediate layer, it is sufficient as long as the support sheet meets the transmittance condition for light (355nm) described above.

[0472] The intermediate layer can be formed using known methods, depending on its type. For example, an intermediate layer with resin as the main component can be formed by molding a resin composition containing said resin.

[0473] As an intermediate layer, for example, a peelability improvement layer that has undergone peeling treatment on one of its faces can be cited.

[0474] • Improved peelability layer

[0475] As a peelability improvement layer, for example, a layer consisting of multiple layers comprising a resin layer and a peeling treatment layer formed on the resin layer can be cited.

[0476] In the composite sheet for forming a protective film, the peelability improvement layer is configured such that the peelability improvement layer is oriented toward the film side for forming the protective film.

[0477] The resin layer in the peelability improvement layer can be produced by molding a resin composition containing resin.

[0478] Furthermore, the peelability improvement layer can be manufactured by peeling one side of the resin layer.

[0479] The removal of the resin layer can be carried out using various known release agents, such as alkyds, silicones, fluorinated compounds, unsaturated polyesters, polyolefins, or waxes.

[0480] In terms of heat resistance, the release agent is preferably an alkyd, silicone, or fluorinated release agent.

[0481] The resin used as a constituent material of the resin layer may be selected appropriately according to the purpose, and there are no particular limitations.

[0482] Preferred resins include, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyethylene (PE), and polypropylene (PP).

[0483] The resin layer can consist of one layer (single layer) or multiple layers (two or more layers). When it consists of multiple layers, these multiple layers can be the same as each other or different from each other, and there is no particular limitation on the combination of these multiple layers.

[0484] The thickness of the release-enhancing layer (the total thickness of the resin layer and the release treatment layer) is preferably 10–2000 nm, more preferably 25–1500 nm, and particularly preferably 50–1200 nm. By making the thickness of the release-enhancing layer above or below the lower limit, the effect of the release-enhancing layer becomes more significant, and the effect of suppressing breakage such as cutting of the release-enhancing layer becomes more effective. By making the thickness of the release-enhancing layer below or below the upper limit, it becomes easier to pick up semiconductor chips, as described later, which have a protective film or a protective film forming film on the back side.

[0485] Preferably, the intermediate layer does not contain, for example, any component that absorbs light (355 nm), or contains only a small amount of such component. Examples of components that absorb light (355 nm) include those found in the substrate described above.

[0486] So far, the description has mainly focused on the case where the support sheet and the protective film forming film are used simultaneously to form a composite sheet for forming a protective film. However, the support sheet may also be used without being used simultaneously with the protective film forming film, and in a state where it does not form a composite sheet for forming a protective film.

[0487] For example, after directly attaching the support sheet to any position on the workpiece, a laser with a wavelength shorter than usual, such as 355nm, is irradiated from outside the workpiece at the attachment position of the support sheet, through the support sheet. This allows for effective printing at the attachment position of the support sheet on the workpiece. Furthermore, the printed text can be clearly identified from outside the workpiece through the support sheet.

[0488] When printing on any position of the workpiece through the support plate, the printing is performed well and the printed characters are easily identifiable, just like when printing on the protective film or protective film formed through the support plate.

[0489] When the support sheet is used in a manner that does not constitute a composite sheet for forming a protective film, the support sheet may be the same as the support sheet used when constituting a composite sheet for forming a protective film.

[0490] As an example of a preferred support sheet in this embodiment, the following can be listed:

[0491] A support sheet comprising a substrate and an adhesive layer disposed on one surface of the substrate.

[0492] The substrate is composed of polyolefin, polyvinyl chloride, or polyester.

[0493] The adhesive layer comprises: an adhesive resin (I-2a) obtained by reacting an acrylic polymer having structural units derived from (meth)acrylate alkyl esters and structural units derived from functional group monomers, and an unsaturated group compound having energy-ray polymerizable unsaturated groups, and a crosslinking agent; or comprises: the acrylic polymer and the crosslinking agent.

[0494] Another example of a preferred support sheet in this embodiment can be listed as follows:

[0495] A support sheet comprising a substrate and an adhesive layer disposed on one surface of the substrate.

[0496] The substrate is composed of polyolefin, polyvinyl chloride, or polyester.

[0497] The adhesive layer comprises: an adhesive resin (I-2a) obtained by reacting an acrylic polymer having structural units from (meth)acrylate alkyl esters and structural units from hydroxyl-containing monomers, and a crosslinking agent, wherein the unsaturated group compound has (meth)acryloyl, vinyl or allyl, and isocyanate or glycidyl groups, or comprises: the acrylic polymer and the crosslinking agent.

[0498] In the composite sheet for forming the protective film of this embodiment, it is preferable that the transmittance of the support sheet to light (355nm) is equal to or greater than the transmittance of the protective film for forming light (355nm) ([transmittance of the support sheet to light (355nm) (%)] ≥ [transmittance of the protective film for forming light (355nm)]). Furthermore, it is more preferable that the transmittance of the support sheet to light (355nm) is greater than the transmittance of the protective film for forming light (355nm) ([transmittance of the support sheet to light (355nm) (%)] > [transmittance of the protective film for forming light (355nm)]). The composite sheet for forming the protective film that satisfies the above conditions has the following superior effect: even when irradiated with a laser with a shorter wavelength than before (e.g., a wavelength of 355nm), it is possible to effectively print text on the protective film for forming the protective film or the protective film itself, and the printed text can be clearly identified through the support sheet.

[0499] In this specification, even after the protective film forming film has been cured, as long as the laminated structure of the support sheet and the cured protective film forming film (e.g., the protective film) can be maintained, the laminated structure is referred to as a "composite sheet for forming a protective film".

[0500] Without impairing the effects of the present invention, the protective film forming composite sheet of this embodiment may have other layers that are not among the substrate, adhesive layer, intermediate layer, protective film forming film and release film.

[0501] The types of other layers are not particularly limited and can be selected arbitrarily according to the purpose.

[0502] The configuration, position, shape, size, etc. of the other layers can be arbitrarily selected according to their type, without any particular limitation.

[0503] The thickness of the workpiece to which the composite sheet for forming the protective film of this embodiment is attached is not particularly limited, but from the point that it is easier to process (e.g., divide) the workpiece described below, it is preferably 30 to 1000 μm, and more preferably 70 to 400 μm.

[0504] The protective film forming composite sheet of this embodiment is used to attach to a workpiece, preferably a semiconductor wafer. The protective film forming composite sheet is preferably attached to the back side of the semiconductor wafer.

[0505] More preferably, the protective film forming composite sheet is used to attach to the back side of the semiconductor wafer, and there is no through trench between the back side of the semiconductor wafer and the circuit forming surface. The protective film forming composite sheet can also be used to attach to the back side of the semiconductor wafer, and there are no through trenches or cracks between the back side of the semiconductor wafer and the circuit forming surface.

[0506] The composite sheet for forming the protective film is not attached to a workpiece after processing. "Workpiece after processing" can be categorized as either a target workpiece being processed or a workpiece in an incomplete processing state. Examples of workpieces in an incomplete processing state include workpieces currently being processed and workpieces in a state where processing has been attempted but partially incomplete. For example, a workpiece in a state where an attempt has been made to diced a semiconductor wafer into semiconductor chips, but some dicing was incomplete.

[0507] Figure 1 A cross-sectional view illustrating an example of a composite sheet for forming a protective film according to one embodiment of the present invention.

[0508] The protective film forming composite sheet 101 shown herein is constructed by having a support sheet 10 and a protective film forming film 13 disposed on one side (sometimes referred to as the "first side") 10a of the support sheet 10.

[0509] The support sheet 10 is formed by having a substrate 11 and an adhesive layer 12 disposed 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 protective film forming film 13.

[0510] That is, the protective film forming composite sheet 101 is formed by sequentially stacking the substrate 11, the adhesive layer 12 and the protective film forming film 13 along their thickness direction.

[0511] The side of the protective film forming film 13 of the support sheet 10 (sometimes referred to as the "first side" in this specification) 10a is the same as the side of the adhesive layer 12 opposite to the substrate 11 side (sometimes referred to as the "first side" in this specification) 12a.

[0512] The composite sheet 101 for forming a protective film further comprises an adhesive layer 16 for clamping and a release film 15 on the protective film forming film 13.

[0513] In the protective film forming composite sheet 101, a protective film forming film 13 is laminated on the entire or almost the entire surface of the first surface 12a of the adhesive layer 12. A clamping adhesive layer 16 is laminated on a portion of the protective film forming film 13 on the side opposite to the adhesive layer 12 (sometimes referred to as the "first surface" in this specification), i.e., near the periphery. Furthermore, a release film 15 is laminated on the area of ​​the first surface 13a of the protective film forming film 13 where the clamping adhesive layer 16 is not laminated, and on the side of the clamping adhesive layer 16 on the side opposite to the protective film forming film 13 (sometimes referred to as the "first surface" in this specification).

[0514] Not limited to the protective film forming composite sheet 101, in the protective film forming composite sheet of this embodiment, the peeling film (e.g., Figure 1 The release film 15 shown can be of any configuration. The composite sheet for forming the protective film in this embodiment may or may not have a release film.

[0515] In the composite sheet 101 for forming a protective film, a gap can be created between the release film 15 and the layer that is in direct contact with the release film 15.

[0516] For example, this shows a state where the release film 15 is in contact (laden) with the side 16c of the adhesive layer 16 for the clamp, but sometimes the side 16c is not in contact with the release film 15. Furthermore, this shows a state where a region near the adhesive layer 16 for the clamp in the first surface 13a of the protective film forming film 13 is in contact (laden) with the release film 15, but sometimes this region is not in contact with the release film 15 either.

[0517] Furthermore, there are cases where the boundaries of the first surface 16a and the side surface 16c of the adhesive layer 16 for the fixture cannot be clearly distinguished.

[0518] The same points apply to composite sheets for forming protective films in other embodiments that include an adhesive layer for clamping.

[0519] The adhesive layer 16 for the fixture is used to fix the composite sheet 101 for forming the protective film onto a fixture such as a ring frame.

[0520] The adhesive layer 16 for the clamp may have a single-layer structure containing adhesive components, or it may have a multi-layer structure in which layers containing adhesive components are stacked on both sides of the sheet that serves as the core material.

[0521] In the composite sheet 101 for forming a protective film, the transmittance of the support sheet 10 to light (355nm) is 20% or more, and the transmittance of the protective film 13 to light (355nm) is 60% or less.

[0522] The protective film forming composite sheet 101 is used in the following manner: with the release film 15 removed, the workpiece (not shown) is attached to any position on the first surface 13a of the protective film forming film 13, and the first surface 16a of the clamping adhesive layer 16 is further attached to a clamp such as an annular frame.

[0523] Figure 2 A cross-sectional view illustrating another example of a composite sheet for forming a protective film according to one embodiment of the present invention.

[0524] In addition, Figure 2 In subsequent figures, for constituent elements that are the same as those shown in the previously described figures, the same symbols are used as in the previously described figures, and their detailed descriptions are omitted.

[0525] The composite sheet 102 for forming the protective film shown is different from the protective film in shape and size, and the adhesive layer for the clamp is stacked on the first side of the adhesive layer instead of the first side of the protective film. Figure 1 The protective film forming composite sheet 101 shown is the same.

[0526] More specifically, in the composite sheet 102 for forming a protective film, the protective film forming film 23 is laminated on a portion of the first surface 12a of the adhesive layer 12, i.e., in the width direction of the adhesive layer 12. Figure 2 On the central side of the region (in the left-right direction). Further, on the region of the first surface 12a of the adhesive layer 12 where the protective film forming film 23 is not laminated, that is, on the region near the periphery, the clamping adhesive layer 16 is laminated. And, on the side of the protective film forming film 23 opposite to the adhesive layer 12 side (sometimes referred to as the "first surface" in this specification) 23a and the first surface 16a of the clamping adhesive layer 16, a release film 15 is laminated.

[0527] Figure 3 A cross-sectional view illustrating yet another example of a protective film forming composite sheet according to one embodiment of the present invention.

[0528] The protective film forming composite sheet 103 shown is configured in addition to having a support sheet 20 instead of a support sheet 10, and lacking an adhesive layer 16 for clamping. Figure 1 The protective film forming composite sheet 101 shown is the same.

[0529] The support sheet 20 is constructed by comprising a substrate 11, an adhesive layer 12 disposed on a first surface 11a of the substrate 11, and an intermediate layer 17 disposed on the first surface 12a of the adhesive layer 12. In the protective film forming composite sheet 103, the intermediate layer 17 is disposed between the adhesive layer 12 and the protective film forming film 23.

[0530] That is, the protective film forming composite sheet 103 is formed by sequentially stacking the substrate 11, the adhesive layer 12, the intermediate layer 17 and the protective film forming film 23 along their thickness directions.

[0531] The side of the protective film forming film 23 of the support sheet 20 (sometimes referred to as the "first side" in this specification) 20a is the same as the first side 12a of the adhesive layer 12.

[0532] The area of ​​the side of the intermediate layer 17 opposite to the side of the adhesive layer 12 (sometimes referred to as the "first side" in this specification) 17a is smaller than the area of ​​the first side 12a of the adhesive layer 12 (i.e., the area formed by combining the area where the protective film forming film 23 is laminated and the area where the protective film forming film 23 is not laminated).

[0533] The planar shape of the first surface 17a of the intermediate layer 17 is not particularly limited; for example, it can be a circle.

[0534] 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. Preferably, the intermediate layer 17 covers the entire surface 23b of the protective film forming film 23 that is opposite to the first surface 23a (sometimes referred to as the "second surface" in this specification).

[0535] Figure 4 A cross-sectional view illustrating yet another example of a protective film forming composite sheet according to one embodiment of the present invention.

[0536] The protective film forming composite sheet 104 shown therein is constructed not only by having a support sheet 30 instead of the support sheet 10, but also by having a support sheet 30 instead of the support sheet 10. Figure 1 The protective film forming composite sheet 101 shown is the same.

[0537] The support sheet 30 is composed only of the substrate 11.

[0538] That is, the protective film forming composite sheet 104 is formed by laminating the substrate 11 and the protective film forming film 13 along their thickness direction.

[0539] The side of the protective film forming film 13 of the support sheet 30 (sometimes referred to as the "first side" in this specification) 30a is the same as the first side 11a of the substrate 11.

[0540] The substrate 11 has adhesiveness at least on its first surface 11a.

[0541] The composite sheet for forming the protective film in this embodiment is not limited to... Figures 1-4 The protective film forming composite sheet shown may be modified or deleted without impairing the effects of the present invention. Figures 1-4 The composite sheet shown is a portion of the composite sheet for forming a protective film, or it may be a composite sheet with additional components added to the composite sheet for forming a protective film described above. More specifically, as described below.

[0542] Up to this point, only composite sheets for forming protective films having a support sheet made of a substrate have been shown. Figure 4 The protective film forming composite sheet 104 shown is an example of a protective film forming composite sheet having a support sheet made of a substrate. Figure 2 The protective film forming composite sheet 102 shown is a protective film forming composite sheet without an adhesive layer 12. However, it is only one example of other protective film forming composite sheets that have a support sheet made of a substrate.

[0543] So far, only composite sheets for forming protective films with an intermediate layer as part of a support sheet have been shown. Figure 3 The protective film forming composite sheet 103 is shown, but as a protective film forming composite sheet having an intermediate layer, other protective film forming composite sheets, such as those shown below, can also be listed. However, the protective film forming composite sheet described below is only one example of other protective film forming composite sheets having an intermediate layer.

[0544] ·exist Figure 1 In the protective film forming composite sheet 101 shown, a protective film forming film 13 is provided between the adhesive layer 12 and the protective film forming film 13. Figure 3 The protective film of the intermediate layer shown is formed using a composite sheet.

[0545] ·exist Figure 2 In the protective film forming composite sheet 102 shown, a protective film forming film 23 is provided between the adhesive layer 12 and the protective film forming film 23. Figure 3 The protective film of the intermediate layer shown is formed using a composite sheet.

[0546] ·exist Figure 4In the protective film forming composite sheet 104 shown, a protective film forming film 13 is provided between the substrate 11 and the protective film forming film 13. Figure 3 The protective film of the intermediate layer shown is formed using a composite sheet.

[0547] Thus far, a composite sheet for forming a protective film with an adhesive layer for clamping has been shown. Figure 1 The protective film forming composite sheet 101 shown Figure 2 The protective film forming composite sheet 102 shown, and Figure 4 The protective film forming composite sheet 104 shown is an example of a protective film forming composite sheet having an adhesive layer for clamping. Figure 3 In the protective film forming composite sheet 103 shown, in the area of ​​the unlaminated intermediate layer 17 and protective film forming film 23 on the first surface 12a of the adhesive layer 12, there is a layer that is consistent with... Figure 1 This is a composite sheet for forming a protective film using the same adhesive layer as the adhesive layer for clamps shown. However, it is only one example of other composite sheets for forming a protective film using the same adhesive layer for clamps.

[0548] and Figure 1 Similar to the protective film forming composite sheet 101 shown, such a protective film forming composite sheet with a clamp adhesive layer is used by attaching the first side of the clamp adhesive layer to a clamp such as a ring frame.

[0549] Thus, regardless of the form of the support sheet and the protective film forming film of the composite sheet for forming the protective film in this embodiment, an adhesive layer for clamping can be provided.

[0550] Thus far, only composite sheets for forming protective films that do not have an adhesive layer for clamping have been shown. Figure 3 The protective film forming composite sheet 103 shown is an example of a protective film forming composite sheet that does not have an adhesive layer for clamping. Figure 2 The protective film forming composite sheet 102 shown is a protective film forming composite sheet without the clamp adhesive layer 16. However, it is only one example of other protective film forming composite sheets that do not have the clamp adhesive layer.

[0551] exist Figures 1-4 In the present embodiment, as components constituting a composite sheet for forming a protective film, a substrate, an adhesive layer, an intermediate layer, a protective film forming film, and a release film are shown. However, the composite sheet for forming a protective film in this embodiment may also include other layers that are not among the above-described components.

[0552] when Figures 1-4 When the composite sheet for forming the protective film shown has the other layers, their placement is not particularly limited.

[0553] In the composite sheet for forming the protective film of this embodiment, the size and shape of each layer can be arbitrarily selected according to the purpose.

[0554] As an example of a preferred composite sheet for forming a protective film in this embodiment, the following can be cited:

[0555] A composite sheet for forming a protective film includes a support sheet and a protective film for forming disposed on one surface of the support sheet.

[0556] The support sheet has a transmittance of over 20% for light with a wavelength of 355nm.

[0557] The protective film used for forming the film has a transmittance of less than 60% for light with a wavelength of 355 nm.

[0558] The support sheet has a substrate and an adhesive layer disposed on one side of the substrate.

[0559] The adhesive layer is disposed between the substrate and the protective film forming film.

[0560] The substrate is composed of polyolefin, polyvinyl chloride, or polyester.

[0561] The adhesive layer comprises: an adhesive resin (I-2a) obtained by reacting an acrylic polymer having structural units derived from (meth)acrylate alkyl esters and structural units derived from functional group monomers, and an unsaturated group compound having energy-ray polymerizable unsaturated groups, and a crosslinking agent; or comprises: the acrylic polymer and the crosslinking agent.

[0562] The protective film forming film is a thermosetting protective film forming film containing polymer component (A), thermosetting component (B), and colorant (I).

[0563] The polymer component (A) is an acrylic resin.

[0564] The thermosetting component (B) is an epoxy thermosetting resin formed from epoxy resin (B1) and thermosetting agent (B2).

[0565] Another example of a preferred composite sheet for forming a protective film in this embodiment can be listed as follows:

[0566] A composite sheet for forming a protective film includes a support sheet and a protective film for forming disposed on one surface of the support sheet.

[0567] The support sheet has a transmittance of over 20% for light with a wavelength of 355nm.

[0568] The protective film used for forming the film has a transmittance of less than 60% for light with a wavelength of 355 nm.

[0569] The support sheet has a substrate and an adhesive layer disposed on one side of the substrate.

[0570] The adhesive layer is disposed between the substrate and the protective film forming film.

[0571] The substrate is composed of polyolefin, polyvinyl chloride, or polyester.

[0572] The adhesive layer comprises: an adhesive resin (I-2a) obtained by reacting an acrylic polymer having structural units from (meth)acrylate alkyl esters and structural units from hydroxyl-containing monomers, and a crosslinking agent, wherein the unsaturated group compound has (meth)acryloyl, vinyl or allyl, and isocyanate or glycidyl groups, or comprises: the acrylic polymer and the crosslinking agent.

[0573] The protective film forming film is a thermosetting protective film forming film containing polymer component (A), thermosetting component (B), and colorant (I).

[0574] The polymer component (A) is a polymer of alkyl (meth)acrylate and hydroxyl-containing (meth)acrylate, wherein the alkyl group constituting the alkyl acrylate has a chain structure with 1 to 18 carbon atoms.

[0575] The thermosetting component (B) is an epoxy thermosetting resin formed from epoxy resin (B1) and thermosetting agent (B2).

[0576] The epoxy resin (B1) is selected from one or more of the group consisting of bisphenol A type epoxy resin, dicyclopentadiene type epoxy resin, and o-cresol phenolic varnish epoxy resin.

[0577] The thermosetting agent (B2) is an amine curing agent containing amino groups.

[0578] The colorant (I) is one or more selected from the group consisting of organic pigments and organic dyes.

[0579] ◇Manufacturing method of composite sheet for forming protective film

[0580] The composite sheet for forming the protective film can be manufactured by stacking the above-mentioned layers in a corresponding positional relationship, and adjusting the shape of some or all of the layers as needed. The formation method of each layer is the formation method described above.

[0581] For example, when manufacturing a support sheet, when laminating an adhesive layer on a substrate, one can simply apply the aforementioned adhesive composition to the substrate and allow it to dry as needed.

[0582] Furthermore, an adhesive layer can also be laminated onto a substrate by coating an adhesive composition onto the release film, drying it as needed to form an adhesive layer on the release film, and then bonding the exposed surface of the adhesive layer to a surface of the substrate. In this case, it is preferable to coat the adhesive composition onto the release-treated surface of the release film.

[0583] While the example described above is of an adhesive layer laminated on a substrate, the method can also be applied to cases where intermediate layers or other layers are laminated on a substrate.

[0584] On the other hand, for example, when further laminating a protective film forming film on an adhesive layer already laminated on a substrate, a protective film forming composition can be applied to the adhesive layer to directly form the protective film forming film. Layers other than the protective film forming film can also be laminated on the adhesive layer using the same method, employing a composition for forming that layer. Thus, when forming a new layer (hereinafter referred to as the "second layer") on any layer already laminated on the substrate (hereinafter referred to as the "first layer"), creating a continuous two-layer laminate structure (in other words, a laminate structure of the first layer and the second layer), a composition for forming the second layer can be applied to the first layer and dried as required.

[0585] However, the second layer is preferably pre-formed on the release film using the composition for forming this layer, and the exposed surface of the pre-formed second layer, opposite to the side in contact with the release film, is adhered to the exposed surface of the first layer, thereby forming a continuous two-layer laminated structure. In this case, it is preferable to apply the composition to the release treatment surface of the release film. After forming the laminated structure, the release film can be removed as needed.

[0586] Here, as an example, the case of forming a protective film by stacking a protective film on an adhesive layer is given, but any stacking structure can be chosen as the object, such as the case of stacking an intermediate layer or other layers on an adhesive layer.

[0587] Thus, all layers of the composite sheet constituting the protective film forming can be laminated by pre-forming them on the release film and attaching them to the surface of the target layer. Therefore, the composite sheet for forming the protective film can be manufactured by appropriately selecting the layers that have undergone the above process according to the requirements.

[0588] Furthermore, protective film forming composite sheets are typically stored with a release film adhered to the surface of the outermost layer (e.g., the protective film forming film) on the side opposite to the support sheet. Therefore, by coating the release film (preferably on its peeling surface) with a composition for forming the outermost layer, such as a protective film forming composition, and drying it as needed, a layer constituting the outermost layer is formed on the release film. Then, by stacking the remaining layers on the exposed surface of this layer opposite to the side in contact with the release film using any of the methods described above, and maintaining the release film adhered without removal, a protective film forming composite sheet with a release film can be obtained.

[0589] ◇Manufacturing method for workpieces with protective film (method of using composite sheet for forming protective film)

[0590] The composite sheet for forming the protective film can be used in the manufacture of the workpiece with the protective film.

[0591] As an example of a method for manufacturing a workpiece with a protective film at any position on the workpiece, the following method is provided: A method for manufacturing a workpiece with a protective film, wherein the protective film is formed from a protective film forming film in a protective film forming composite sheet; when the protective film forming film is curable, the cured product of the protective film forming film is the protective film; when the protective film forming film is non-curable, the protective film forming film attached to any position on the workpiece is the protective film. The method for manufacturing a workpiece with a protective film includes the following steps: attaching the protective film forming film in the protective film forming composite sheet to a target position on the workpiece. The process includes an attachment step for fabricating a first laminate on the workpiece, wherein the protective film forming composite sheet is disposed (layered) thereon; a printing step for printing characters onto the protective film forming film or protective film in the first laminate by irradiating the protective film forming composite sheet with a laser from the outside of the support sheet side of the protective film forming composite sheet, thereby printing characters onto the protective film forming film or protective film; and a processing step for fabricating the workpiece by processing the workpiece after the printing step. When the protective film forming film is curable, a further curing step is performed after the attachment step to form the protective film by curing the protective film forming film.

[0592] Whether the protective film forming film and the protective film are treated in each subsequent step depends on the timing of the protective film formation. When the protective film forming film is non-curable, treatment performed after the application step results in a protective film in any step. When the protective film forming film is curable, treatment performed before the curing step results in a protective film forming film, while treatment performed after the curing step results in a protective film.

[0593] Therefore, in the printing process, a laser is irradiated onto the protective film forming membrane in the first laminate from the outside of the support sheet side of the protective film forming composite sheet, through the support sheet, thereby printing the protective film; or a laser is irradiated onto the protective film in the first laminate from the outside of the support sheet side of the protective film forming composite sheet, through the support sheet, thereby printing the protective film.

[0594] As an example of a method for manufacturing a semiconductor chip with a protective film, where the workpiece is a semiconductor wafer, an example of such a method is provided: a method for manufacturing a semiconductor chip with a protective film, wherein a protective film is provided on the back side of the semiconductor chip. In this method, the protective film is formed from a protective film forming film in a protective film forming composite sheet. When the protective film forming film is curable, the cured product of the protective film forming film is the protective film; when the protective film forming film is non-curable, the protective film forming film attached to the back side of the semiconductor wafer is the protective film. The method for manufacturing a semiconductor chip with a protective film includes the following steps: by attaching the protective film forming film in the protective film forming composite sheet to the back side of the semiconductor wafer, a protective film is formed on the back side of the semiconductor wafer (by laminating the protective film). The process includes: an attachment step of the first laminate of the protective film forming composite sheet; a printing step of irradiating the protective film forming film or protective film in the first laminate with a laser from the outside of the support sheet side of the protective film forming composite sheet, thereby printing characters on the protective film forming film or protective film; a dicing step of dicing the semiconductor wafer after the printing step to produce the semiconductor chip; a cutting step of cutting the protective film forming film or protective film after the printing step; and a picking step of separating and picking up the semiconductor chip having the cut protective film forming film or protective film from the support sheet. When the protective film forming film is curable, a curing step of forming the protective film by curing the protective film forming film is further included after the attachment step.

[0595] In the manufacturing method, the wavelength of the laser is preferably shorter than that of conventional wavelengths, and more preferably 355 nm.

[0596] In the manufacturing method described above, when the workpiece is a semiconductor wafer, the workpiece described above can be used as the workpiece.

[0597] In the manufacturing method described above, by using the protective film forming composite sheet of this embodiment, even when irradiated with a short-wavelength laser such as 355 nm, the protective film forming film or the protective film in the protective film forming composite sheet can be well printed. Furthermore, the printed text can be well identified from the outside of the support sheet side of the protective film forming composite sheet, with the support sheet in between.

[0598] The manufacturing method can be divided into a manufacturing method having the curing process (sometimes referred to as "manufacturing method (1)" in this specification) and a manufacturing method not having the curing process (sometimes referred to as "manufacturing method (2)" in this specification).

[0599] The manufacturing methods will be explained in turn below.

[0600] Manufacturing Method (1)

[0601] The manufacturing method (1) is a method for manufacturing a workpiece with a protective film having a protective film at any position on the workpiece. The protective film is formed by a protective film forming film in a protective film forming composite sheet. Since the protective film forming film is curable, the cured product of the protective film forming film is the protective film. The manufacturing method of the workpiece with the protective film includes the following steps: by attaching the protective film forming film in the protective film forming composite sheet to a target position on the workpiece, a protective film is formed on the workpiece. The process includes: an attachment step of the first laminate of a film-forming composite sheet; a curing step of forming a protective film by curing the protective film-forming film after the attachment step; a printing step of printing characters on the protective film-forming film or protective film in the first laminate by irradiating the protective film-forming composite sheet or protective film with a laser from the outside of the support sheet side of the protective film-forming composite sheet after the attachment step; and a processing step of producing the workpiece by processing the workpiece after the printing step.

[0602] When the workpiece is a semiconductor wafer, the manufacturing method (1) is a method for manufacturing a semiconductor chip with a protective film on the back side of the semiconductor chip. The protective film is formed by a protective film forming film in a protective film forming composite sheet. Since the protective film forming film is curable, the cured product of the protective film forming film is the protective film. The manufacturing method of the semiconductor chip with a protective film includes the following steps: attaching the protective film forming film in the protective film forming composite sheet to the back side of the semiconductor wafer to create a first laminate on the back side of the semiconductor wafer where the protective film forming composite sheet is disposed (stacked); after the attachment step, by making the protective film... The process includes: a curing step for curing a protective film to form the protective film; a printing step for printing characters onto the protective film forming film or protective film in the first laminate by irradiating it with a laser from the outside of the support sheet side of the protective film forming composite sheet, separated from the support sheet, after the mounting step; a dicing step for fabricating the semiconductor chip by dicing the semiconductor wafer after the printing step; a cutting step for cutting the protective film forming film or protective film after the printing step; and a picking step for separating and picking up the semiconductor chip having the cut protective film forming film or protective film from the support sheet.

[0603] When the workpiece is a semiconductor wafer, the order of the dicing and cutting processes can be arbitrarily selected according to the purpose. The cutting process can be performed after the dicing process, or the dicing and cutting processes can be performed simultaneously, or the dicing process can be performed after the cutting process.

[0604] In this embodiment, regardless of the order in which the semiconductor wafer is diced and the protective film is formed or the protective film is cut, if the semiconductor wafer is diced and the protective film is formed or the protective film is cut continuously through the same operation without interruption, it is considered that the dicing process and the cutting process are performed simultaneously.

[0605] Both the slitting and cutting processes can be performed using known methods, depending on the order in which these processes are performed.

[0606] When performing a dicing process after the dicing process, the dicing (in other words, singulation) of semiconductor wafers can be carried out, for example, by Stealth Dicing (registered trademark) or laser cutting.

[0607] Stealth Dicing (registered trademark) refers to the method described below. First, a predetermined dicing position is defined inside a semiconductor wafer. A laser is then irradiated with this position as the focal point, thereby forming a modified layer inside the semiconductor wafer. Unlike other locations on the semiconductor wafer, the modified layer is modified by laser irradiation, resulting in a weakened intensity. Therefore, by applying force to the semiconductor wafer, cracks extending along both sides of the semiconductor wafer are generated at the modified layer inside the wafer, becoming the starting point for dicing (cutting) the semiconductor wafer. Then, force is applied to the semiconductor wafer to dice it at the modified layer location, thus fabricating a semiconductor chip.

[0608] When performing a cutting process after the dicing process, the cutting of the protective film forming film or the protective film itself can be performed, for example, by stretching the protective film forming film or the protective film in a direction parallel to the surface to which it is attached to the semiconductor chip, a process known as expansion. The expanded protective film forming film or the protective film is then cut along the outer periphery of the semiconductor chip. Cutting based on such expansion is preferably performed at a low temperature such as -20 to 5°C.

[0609] When performing both dicing and cutting processes, various cutting methods can be used, such as blade dicing, laser cutting based on laser irradiation, or water cutting based on water spray containing abrasive, to simultaneously dicing semiconductor wafers and cutting protective films or protective films.

[0610] Furthermore, by forming a modified layer through Stealth Dicing and simultaneously expanding an undivided semiconductor wafer and a protective film forming film or protective film using the same method as described above, it is also possible to simultaneously divide the semiconductor wafer and cut the protective film forming film or protective film.

[0611] When performing a dicing process after the dicing process, the same cutting techniques as described above can be used to cut the protective film forming film or protective film without dividing the semiconductor wafer. Then, the semiconductor wafer can be divided by breaking.

[0612] Figures 5A-5E This is a cross-sectional view illustrating an example of the manufacturing method (1) when the workpiece is a semiconductor wafer. Wherein, for using Figure 1 The manufacturing method of the protective film forming composite sheet 101 shown will be described.

[0613] <Attachment Process>

[0614] In the bonding process, a protective film forming composite sheet with the release film 15 removed is used as the protective film forming composite sheet 101, such as... Figure 5A As shown, the protective film forming film 13 of the protective film forming composite sheet 101 is attached to the back side 9b of the semiconductor wafer 9. Thus, a first laminate 901 is fabricated by comprising the semiconductor wafer 9 and the protective film forming composite sheet 101 disposed on its back side 9b.

[0615] In the attachment process, the protective film 13 can be softened by heating and then attached to the semiconductor wafer 9.

[0616] Additionally, the diagram of bumps, etc., on the circuit forming surface 9a is omitted here in the semiconductor wafer 9.

[0617] Furthermore, the symbol 13b indicates the side of the protective film forming film 13 that is opposite to the first side 13a (in other words, the side of the adhesive layer 12) (sometimes referred to as the "second side" in this specification).

[0618] To achieve the target thickness of semiconductor wafer 9, its back side can be ground. That is, the back side 9b of semiconductor wafer 9 can be a grinding surface.

[0619] In the semiconductor wafer 9, it is preferable that there is no through trench between its circuit formation surface 9a and back surface 9b.

[0620] <Curing Process>

[0621] In the curing process following the attachment process, such as Figure 5B As shown, the protective film is formed by curing the film 13 to form a protective film 13'.

[0622] Here, a curing process is shown before the printing process.

[0623] In this embodiment, regardless of whether the cured material obtained by curing the protective film forming film 13 attached to the semiconductor wafer 9 is cut, the cured material is used as the protective film.

[0624] By performing a curing process, the protective film forming composite sheet 1011 becomes the protective film forming film 13 and the protective film forming film 13', and a first laminate 9011 with a semiconductor wafer 9 and the protective film forming composite sheet 1011 disposed on its back side 9b is obtained.

[0625] Symbol 13a' represents the first surface of the protective film 13' corresponding to the first surface 13a of the protective film forming film 13, and symbol 13b' represents the second surface of the protective film 13' corresponding to the second surface 13b of the protective film forming film 13.

[0626] In the curing process, when the protective film forming film 13 is thermosetting, the protective film forming film 13 is formed by heating the protective film forming film 13. When the protective film forming film 13 is energy-curable, the protective film forming film 13 is formed by irradiating the protective film forming film 13 with energy rays through the support sheet 10.

[0627] In the curing process, the curing conditions of the protective film forming film 13, namely the heating temperature and heating time during thermal curing and the irradiance and light intensity of the energy rays during energy ray curing, are as described above.

[0628] <Printing Process>

[0629] In the printing process following the affixing process, such as Figure 5C As shown, laser L is irradiated from the outside of the support sheet 10 side of the protective film forming composite sheet 1011 in the cured first laminate 9011 through the support sheet 10, thereby printing on the protective film 13'. Printing is also performed on the second surface 13b' of the protective film 13' (illustration omitted).

[0630] By performing the printing process, the protective film forming composite sheet 1011 becomes a protective film forming composite sheet 1012 having a printed protective film 13', and a first laminate 9012 having a printed and cured structure consisting of a semiconductor wafer 9 and a protective film forming composite sheet 1012 disposed on its back side 9b is obtained.

[0631] Preferably, the wavelength of the laser L is shorter than that of conventional wavelengths, more preferably 355 nm.

[0632] During the printing process, even when irradiated with a short wavelength laser L such as 355 nm, the protective film 13' in the protective film forming composite sheet 1011 can be printed well. Furthermore, the printed text can be clearly identified from the outside of the support sheet 10 side of the protective film forming composite sheet 1012, with the support sheet 10 in between.

[0633] <Segmentation process, cutting process>

[0634] In this embodiment, after the printing process, the semiconductor wafer 9 is divided to perform a dicing process for manufacturing a semiconductor chip and a cutting process for cutting the protective film 13'.

[0635] The order of the division and cutting processes is the same as described above and is not limited.

[0636] The methods for performing the division and cutting processes are the same as those described above.

[0637] like Figure 5D As shown, through a dicing and cutting process, a plurality of semiconductor chips 91 with protective films are obtained, each consisting of a semiconductor chip 9' and a cut protective film 130' disposed on the back surface 9b' of the semiconductor chip 9'. The plurality of semiconductor chips 91 with protective films are arranged on a support sheet 10, and these semiconductor chips 91 with protective films and the support sheet 10 constitute a semiconductor chip group 910 with protective films.

[0638] Symbol 130a' represents the first side of the protective film 130' after it has been cut, corresponding to the first side 13a' of the protective film 13', and symbol 130b' represents the second side of the protective film 130' after it has been cut, corresponding to the second side 13b' of the protective film 13'.

[0639] The symbol 9a' represents the circuit formation surface of the semiconductor chip 9' corresponding to the circuit formation surface 9a of the semiconductor wafer 9.

[0640] <Pickup Process>

[0641] In the picking process following the segmentation and cutting processes, such as Figure 5E As shown, the semiconductor chip 9' (semiconductor chip 91 with protective film) with the cut protective film 130' is separated from and picked up from the support sheet 10. The direction of picking is indicated by arrow I.

[0642] Picking up the semiconductor chip 91 with a protective film can be performed using known methods. For example, a vacuum chuck or the like can be used as a separation means 8 for separating the semiconductor chip 91 with a protective film from the support sheet 10. Note that only the separation means 8 is not shown in cross-section.

[0643] Thus, a semiconductor chip 91 with a protective film was obtained as the target.

[0644] Taking the picked-up semiconductor chip with a protective film as an example, in the semiconductor chip 91 with a protective film that was once the object of the printing process, clear printing is maintained on the second side 130b' of the cut protective film 130'.

[0645] <Timing of the curing process>

[0646] So far, although the case of performing a curing process between the bonding process and the printing process has been explained, the timing of the curing process in manufacturing method (1) is not limited to this. For example, in manufacturing method (1), the curing process can be performed at any time between the printing process and the cutting process, between the printing process and the cutting process, between the cutting process and the picking process, between the cutting process and the picking process, and after the picking process.

[0647] During the curing process following the bonding and printing processes, in the printing process, the protective film forming composite sheet 101 is cured from the outside of the support sheet 10 side, with the support sheet 10 in between. Figure 5A Laser L is used to irradiate the protective film forming membrane 13 in the protective film forming composite sheet 101 of the first laminate 901 shown, thereby printing text on the protective film forming membrane 13. The text is printed on the second surface 13b of the protective film forming membrane 13 (illustration omitted).

[0648] At this point, the printing process can be performed in the same way as the printing process described above, except that the laser L irradiates the protective film forming film 13 instead of the protective film 13'.

[0649] During the printing process, even when irradiated with a short wavelength laser L such as 355 nm, the protective film forming film 13 in the protective film forming composite sheet 101 can be printed well. Furthermore, the printed text can be clearly identified from the outside of the support sheet 10 side of the protective film forming composite sheet 101, with the support sheet 10 in between.

[0650] <Other processes>

[0651] In addition to each of the aforementioned processes, such as the attaching process, curing process, printing process, dividing process, cutting process and picking process, the manufacturing method (1) may also have other processes that do not belong to any of these processes.

[0652] The types of other processes and the timing of performing them can be arbitrarily selected according to the purpose, without any particular limitation.

[0653] Manufacturing Methods (2)

[0654] The manufacturing method (2) is a method for manufacturing a workpiece with a protective film having a protective film at any position on the workpiece. The protective film is formed by the protective film forming film in the protective film forming composite sheet. Since the protective film forming film is non-curable, the protective film forming film attached to any position on the workpiece is the protective film. The manufacturing method of the workpiece with the protective film includes the following steps: an attachment step in which the protective film forming film in the protective film forming composite sheet is attached to a target position on the workpiece to form a first laminate on the workpiece having the protective film forming composite sheet disposed (layered); after the attachment step, a printing step in which the protective film in the protective film forming composite sheet in the first laminate is irradiated with a laser from the outside of the support sheet side of the protective film forming composite sheet through the support sheet to print characters on the protective film; and a processing step in which the workpiece is processed after the printing step to form the workpiece. In manufacturing method (2), the protective film formed after the workpiece is attached in the attachment process is a protective film.

[0655] Regardless of the type of workpiece, manufacturing method (2) is the same as manufacturing method (1) except that it does not have the curing process and directly uses the protective film formed after being attached to the workpiece as the protective film. It also has the same effect as manufacturing method (1).

[0656] Thus far, although mainly for use Figure 1 The manufacturing method of the workpiece with protective film when the protective film forming composite sheet 101 is shown has been described, but the manufacturing method of the workpiece with protective film in this embodiment is not limited thereto.

[0657] For example, even when using Figures 2-4 The protective film forming composite sheet, etc. shown, except Figure 1 Composite sheets other than the protective film forming composite sheet 101 shown can also be used to manufacture workpieces with protective films using the same manufacturing method described above.

[0658] When using a protective film forming composite sheet of other embodiments, the process described above can be appropriately modified, altered, or deleted based on the structural differences between the sheet and the protective film forming composite sheet 101, thereby manufacturing a workpiece with a protective film.

[0659] ◇ Method for manufacturing workpieces with protective films (method for using protective film forming film)

[0660] The protective film forming film, which does not constitute the composite sheet for forming the protective film, can also be used in the manufacture of the workpiece with the protective film.

[0661] As another example of the method for manufacturing a workpiece with a protective film, a method for manufacturing a workpiece with a protective film can be listed, wherein the protective film is formed from a protective film forming film that does not constitute the protective film forming composite sheet; when the protective film forming film is curable, the cured product of the protective film forming film is the protective film; when the protective film forming film is non-curable, the protective film forming film attached to any position on the workpiece is the protective film; the method for manufacturing a workpiece with a protective film includes the following steps: by attaching the protective film forming film to a target position on the workpiece, thereby manufacturing the workpiece... The process includes an attachment step on which the protective film forming film or protective film is stacked; a printing step after the attachment step on which the protective film forming film or protective film in the second stack is directly irradiated with a laser from the outside of the protective film forming film or protective film on the side opposite to the workpiece side, thereby printing characters on the protective film forming film or protective film; and a processing step after the printing step on which the workpiece is processed to produce the workpiece workpiece. When the protective film forming film is curable, a curing step is further included after the attachment step to form the protective film by curing the protective film forming film.

[0662] Whether the protective film forming film and the protective film are treated in each subsequent step depends on the timing of the protective film formation. When the protective film forming film is non-curable, treatment performed after the application step results in a protective film in any step. When the protective film forming film is curable, treatment performed before the curing step results in a protective film forming film, while treatment performed after the curing step results in a protective film.

[0663] Therefore, in the printing process, the protective film forming film in the second laminate is printed by directly irradiating it with a laser from the outside of the protective film forming film, which is opposite to the workpiece side, or the protective film in the second laminate is printed by directly irradiating it with a laser from the outside of the protective film, which is opposite to the workpiece side.

[0664] As an example of a method for manufacturing a semiconductor chip with a protective film, where the workpiece is a semiconductor wafer, an example of such a method is provided: a method for manufacturing a semiconductor chip with a protective film, wherein the protective film is formed from a protective film forming film that does not constitute the protective film forming composite sheet. When the protective film forming film is curable, the cured product of the protective film forming film is the protective film; when the protective film forming film is non-curable, the protective film forming film attached to the back of the semiconductor wafer is the protective film. The method for manufacturing a semiconductor chip with a protective film includes the following steps: an attachment step in which the protective film forming film or a second laminate having the protective film forming film or the protective film disposed (stacked) on the back of the semiconductor wafer is formed by attaching the protective film forming film to the back of the semiconductor wafer; after the attachment step, the protective film is formed from the protective film forming film... A printing process is described, in which the outer side of the protective film or protective film opposite to the semiconductor wafer side is directly irradiated with a laser to print characters onto the protective film or protective film in the second laminate; a stacking process is described, after the printing process, a dicing process is described, in which dicing wafers are stacked onto the side of the protective film or protective film opposite to the semiconductor wafer side, or onto the side of the semiconductor wafer opposite to the protective film or protective film side; a dicing process is described, after the stacking process, a dicing process is described, in which the semiconductor wafer is diced (cut) to produce the semiconductor chip; a cutting process is described, after the stacking process, a cutting process is described, in which the protective film or protective film is cut; and a picking process is described, in which the semiconductor chip having the cut protective film or protective film is separated from the dicing wafer and picked up; and when the protective film or protective film is curable, a curing process is described, after the attaching process, a curing process is described, in which the protective film is formed by curing the protective film or protective film.

[0665] Except for using the aforementioned protective film forming film instead of the protective film forming composite sheet, the manufacturing method of the workpiece with a protective film when using a protective film forming film that does not constitute a protective film forming composite sheet is the same as the manufacturing method of the workpiece with a protective film when using a protective film forming composite sheet. Other steps that are different from those when using a protective film forming composite sheet can be added as needed.

[0666] For example, when manufacturing a semiconductor chip with a protective film as a workpiece with a protective film, as described above, it is necessary to perform an additional lamination process to laminate the dicing and cutting processes required in the dicing and cutting processes onto the protective film forming film, the protective film, or the semiconductor wafer.

[0667] In the lamination process, the protective film forming film or the surface of the protective film, which is the object to be laminated as a cutting sheet, is the surface on which the printing process is performed.

[0668] In the stacking process, the surface of the semiconductor wafer, which is the object to be stacked as a dicing sheet, is the circuit forming surface.

[0669] The cutting disc can be a known cutting disc, and the lamination process can be performed using known methods.

[0670] In this embodiment, when the dicing wafer is stacked on a protective film forming film or a protective film, the dicing process and the cutting process are performed simultaneously after the stacking process, or the cutting process is performed after the dicing process. In contrast, when the dicing wafer is stacked on a semiconductor wafer, the dicing process and the cutting process are performed simultaneously after the stacking process, or the dicing process is performed after the cutting process.

[0671] In the printing process, the printing surface of the protective film or the protective film is exposed, and the exposed surface of the protective film or the protective film is directly irradiated with a laser without any material in between.

[0672] The manufacturing method can be divided into a manufacturing method having the curing process (sometimes referred to as "manufacturing method (3)" in this specification) and a manufacturing method not having the curing process (sometimes referred to as "manufacturing method (4)" in this specification).

[0673] The manufacturing methods will be explained in turn below.

[0674] Manufacturing Methods (3)

[0675] The manufacturing method (3) is a method for manufacturing the workpiece with a protective film, wherein the protective film is formed from a protective film forming film that does not constitute the protective film forming composite sheet. Since the protective film forming film is curable, the cured product of the protective film forming film is the protective film. The method for manufacturing the workpiece with a protective film includes the following steps: an attachment step in which the protective film forming film is attached to a target position on the workpiece to form a second laminate on the workpiece having the protective film forming film disposed (layered); a curing step in which the protective film is cured after the attachment step to form the protective film; a printing step in which the protective film forming film is directly irradiated with a laser from the outside of the protective film forming film or the protective film on the side opposite to the workpiece side to print characters on the protective film forming film or the protective film; and a processing step in which the workpiece is processed after the printing step to produce the workpiece.

[0676] When the workpiece is a semiconductor wafer, the manufacturing method (3) is a manufacturing method for the semiconductor chip with a protective film, wherein the protective film is formed from a protective film forming film that does not constitute the protective film forming composite. Since the protective film forming film is curable, the cured product of the protective film forming film is the protective film. The manufacturing method for the semiconductor chip with a protective film includes the following steps: an attachment step in which the protective film forming film is attached to the back side of the semiconductor wafer to form a second laminate on the back side of the semiconductor wafer having the protective film forming film disposed (stacked); after the attachment step, a curing step in which the protective film forming film is cured to form the protective film; after the attachment step, a curing step in which the protective film is cured from the protective film forming film or the protective film and the semiconductor wafer. A printing process is performed whereby a laser is directly irradiated onto the protective film or protective film in the second laminate, with the outer side opposite to the semiconductor wafer side, thereby printing characters onto the protective film or protective film; a stacking process is performed whereby a dicing wafer is stacked on the surface of the protective film or protective film opposite to the semiconductor wafer side, or on the surface of the semiconductor wafer opposite to the protective film or protective film side, after the stacking process; a dicing process is performed where the semiconductor wafer is diced (cut) to produce the semiconductor chip after the stacking process; a cutting process is performed where the protective film or protective film is cut after the stacking process; and a picking process is performed where the semiconductor chip having the cut protective film or protective film is separated from the dicing wafer and picked up.

[0677] Manufacturing Methods (4)

[0678] The manufacturing method (4) is a method for manufacturing the workpiece with a protective film, wherein the protective film is formed from a protective film forming film that does not constitute the protective film forming composite sheet. Since the protective film forming film is non-curable, the protective film forming film attached to any position of the workpiece is the protective film. The manufacturing method for the workpiece with a protective film includes the following steps: an attachment step of attaching the protective film forming film to a target position of the workpiece to create a second laminate on the workpiece having the protective film disposed (layered); after the attachment step, a printing step of directly irradiating the protective film in the second laminate with a laser from the outside of the protective film, opposite to the side of the workpiece, to print characters on the protective film; and a processing step of processing the workpiece after the printing step to create the workpiece. In the manufacturing method (4), the protective film forming film attached to the workpiece in the attachment step is the protective film.

[0679] Regardless of the type of workpiece, manufacturing method (4) is the same as manufacturing method (3) except that it does not have the curing process and directly uses the protective film formed after being attached to the workpiece as the protective film. It also has the same effect as manufacturing method (3).

[0680] ◇Semiconductor device manufacturing method

[0681] After obtaining the workpiece with a protective film through the above manufacturing method, the workpiece with the protective film can be used to manufacture a semiconductor device using a known appropriate method, depending on its type. For example, when the workpiece with the protective film is a semiconductor chip with a protective film, a semiconductor package can be formed by flip-chip bonding the semiconductor chip with the protective film on the circuit formation surface of the substrate, and the target semiconductor device can be manufactured using the semiconductor package (illustration omitted).

[0682] Example

[0683] The present invention will now be described in more detail through specific embodiments. However, the present invention is not limited to any of the embodiments shown below.

[0684] <Raw materials for resin manufacturing>

[0685] The following shows the official names of the raw materials used to manufacture the resin, which are abbreviated in this embodiment and comparative example.

[0686] MA: Methyl acrylate

[0687] MMA: Methyl methacrylate

[0688] HEA: 2-Hydroxyethyl acrylate

[0689] 2EHA: 2-Ethylhexyl acrylate

[0690] MOI: 2-Methacryloxyethyl isocyanate

[0691] <Raw materials for preparing the composition for forming protective film>

[0692] The following are the raw materials used to prepare compositions for forming protective films.

[0693] [Polymer component (A)]

[0694] (A)-1: An acrylic polymer copolymer composed of MA (85 parts by mass) and HEA (15 parts by mass) (weight average molecular weight 370,000, glass transition temperature 6°C).

[0695] (A)-2: An acrylic polymer copolymer (weight average molecular weight 400,000, glass transition temperature 20°C) copolymerized from MA (65 parts by mass), MMA (20 parts by mass) and HEA (15 parts by mass).

[0696] [Thermosetting component (B1)]

[0697] (B1)-1: Bisphenol A type epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 184-194 g / eq)

[0698] (B1)-2: Bisphenol A type epoxy resin ("jER1055" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 800-900 g / eq)

[0699] (B1)-3: Dicyclopentadiene type epoxy resin (“EPICLON HP-7200HH” manufactured by DIC CORPORATION, epoxy equivalent 255-260 g / eq)

[0700] (B1)-4: Cresol-phenolic varnish-type epoxy resin with addition of acryloyl group ("CNA-147" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 518 g / eq)

[0701] [Thermosetting agent (B2)]

[0702] (B2)-1: Dicyandiamide (ADEKA HARDENER EH-3636AS manufactured by ADEKA CORPORATION, a thermoactive latent epoxy resin curing agent with an active hydrogen equivalent of 21 g / eq)

[0703] [Curning Accelerator (C)]

[0704] (C)-1: 2-Phenylon-4,5-Dihydroxymethylimidazol (CUREZOL 2PHZ manufactured by SHIKOKU CHEMICALS CORPORATION)

[0705] [Filling Material (D)]

[0706] (D)-1: Silica filler (Admatechs "SC2050MA", a silica filler with surface modification using epoxy compounds, average particle size 0.5μm)

[0707] (D)-2: Spherical silica (Admatechs "YA050C-MJE", average particle size 0.05μm)

[0708] [Coupled agent (E)]

[0709] (E)-1:3-Aminopropyltrimethoxysilane (“A-1110” manufactured by NUC Corporation)

[0710] [Coloring agent (I)]

[0711] (I)-1: A black pigment prepared by mixing three organic pigments (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.)

[0712] [Example 1]

[0713] The Manufacturing of Support Sheets

[0714] <Manufacturing of Adhesive Resin (I-2a)>

[0715] MOI (in an amount such that the total molar number of isocyanate groups in MOI is 0.75 times the total molar number of hydroxyl groups from HEA in the acrylic polymer) was added to an acrylic polymer with a weight average molecular weight of 600,000, which is a copolymer of 2EHA (80 parts by mass) and HEA (20 parts by mass), and the addition reaction was carried out in an air stream at 50°C for 48 hours to obtain the target adhesive resin (I-2a)-1.

[0716] Hereinafter, the acrylic polymer will sometimes be referred to as “adhesive resin (I-1a)-1”.

[0717] <Preparation of Adhesive Composition (I-2)>

[0718] An energy-curable adhesive composition (I-2)-1 was prepared, comprising an adhesive resin (I-2a)-1 (100 parts by mass), a hexamethylene diisocyanate crosslinking agent ("CORONATE HL" manufactured by TOSOH CORPORATION) (4 parts by mass), and a photopolymerization initiator ("Irgacure 184", 1-hydroxycyclohexylphenyl ketone manufactured by BASF) (3 parts by mass), and further comprising methyl ethyl ketone as a solvent, wherein the total concentration of all components except the solvent is 25% by mass. Furthermore, the contents of components other than methyl ethyl ketone shown herein refer to the contents of the target substance excluding the solvent.

[0719] <Manufacturing of the Support Sheet>

[0720] Using a release film ("SP-PET381031", manufactured by Lintec Corporation, with a thickness of 38 μm) that has undergone single-sided peeling treatment on a silicone-treated polyethylene terephthalate film, the adhesive composition (I-2)-1 obtained above is applied to the peeled surface of the release film, and then heated and dried at 100°C for 2 minutes to form an energy-curable adhesive layer with a thickness of 5 μm.

[0721] Next, by attaching a polypropylene film (1) (80 μm thick, colorless) as a substrate to the exposed surface of the adhesive layer, a laminated sheet, i.e. a support sheet with a release film, is manufactured by sequentially stacking the substrate, adhesive layer and release film along their thickness direction.

[0722] For the polypropylene film (1), a tensile test was conducted at 23°C with a tensile speed of 200 mm / min according to JIS K 7127, and the Young's modulus was measured to be 510 MPa.

[0723] Manufacturing of membranes for protective film formation

[0724] <Preparation of the protective film forming composition (III-1)>

[0725] The polymer component (A)-1 (150 parts by mass), thermosetting component (B1)-1 (60 parts by mass), (B1)-2 (10 parts by mass), (B1)-3 (30 parts by mass), (B2)-1 (2 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (300 parts by mass), coupling agent (E)-1 (0.5 parts by mass), and colorant (I)-1 (17 parts by mass) 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 45% by mass for all components except the solvent. Furthermore, the amounts of components other than the mixed solvent shown here are the amounts of the target material excluding the solvent.

[0726] Manufacturing of membranes for protective film formation

[0727] Using a release film (second release film, "SP-PET381031" manufactured by Lintec Corporation, with a thickness of 38 μm) that has undergone a single-sided release treatment on a polyethylene terephthalate film prepared by silicone treatment, the above-mentioned protective film forming composition (III-1)-1 is coated onto the release-treated surface of the second release film and dried at 100°C for 2 minutes, thereby producing a thermosetting protective film forming film with a thickness of 15 μm.

[0728] Furthermore, a release treatment surface of a release film (a first release film, "SP-PET381031" manufactured by Lintec Corporation, with a thickness of 38 μm) is attached to the exposed surface of the protective film forming film on the side without the second release film, thereby obtaining a laminated film comprising a protective film forming film, a first release film disposed on one side of the protective film forming film, and a second release film disposed on the other side of the protective film forming film.

[0729] Manufacturing of Composite Sheets for Protective Film Formation

[0730] Remove the release film from the support sheet obtained above. Furthermore, remove the first release film from the laminated film obtained above. Then, bond the exposed surface of the adhesive layer obtained by removing the release film to the exposed surface of the protective film forming film obtained by removing the first release film, thereby manufacturing a protective film forming composite sheet composed of a substrate, an adhesive layer, a protective film forming film, and a second release film sequentially laminated along their thickness directions.

[0731] Evaluation of Supporting Films

[0732] <Determination of the transmittance of the support sheet to light (355nm)>

[0733] The release film was removed from the support sheet obtained above. Then, for this support sheet, the transmittance of light in the wavelength range of 190–1200 nm was measured using a spectrophotometer (Shimadzu Corporation's "UV-VIS-NIR SPECTROPHOTO METER UV-3600"). At this time, the large sample chamber "MPC-3100" attached to the spectrophotometer was used, along with the integrating sphere built into the spectrophotometer. The transmittance of light (355 nm) was then calculated based on the obtained measurement results. The results are shown in Table 1.

[0734] <Measurement of the transmittance of the substrate to light (355nm)>

[0735] For the polypropylene film (1) used in the manufacture of the support sheet, the transmittance of light (355 nm) was calculated using the same method as for the support sheet. The results are shown in Table 1.

[0736] Evaluation of membranes used for protective film formation

[0737] <Determination of transmittance of light (355nm)>

[0738] For the protective film obtained by removing the first and second release films from the laminated film obtained above, the transmittance of light (355 nm) was measured using the same method as that used for the support sheet described above. The results are shown in Table 1.

[0739] Evaluation of Composite Sheets for Protective Film Formation

[0740] <Evaluation of Printing Suitability and Printing Visibility>

[0741] Remove the second release film from the protective film forming composite sheet obtained above, and attach the exposed surface of the resulting protective film forming film to the polished surface of the back side of an 8-inch silicon wafer (thickness of 350 μm) to obtain a first laminate consisting of the protective film forming composite sheet and the silicon wafer.

[0742] Next, the first laminate is heated in an oven at 130°C for 2 hours to heat-cur the protective film, thereby forming a protective film.

[0743] Next, through the support sheet, a laser is irradiated onto the protective film in the first laminate obtained by thermosetting, from the outside of the support sheet side of the composite sheet for forming the protective film, thereby printing text onto the protective film. At this time, the laser wavelength is set to 355nm, the laser frequency is set to 40kHz, the laser output is set to 0.30W, and the size of each character is set to 1cm vertically and 0.8cm horizontally, printing a line of four letters "ABCD".

[0744] Next, in the first laminate obtained by printing and curing, the substrate and adhesive layer (i.e., the support sheet) were removed from the printed protective film, and five evaluators directly observed the printed surface of the protective film with the naked eye. Then, the printability and print visibility of the composite sheet for forming the protective film were evaluated according to the following criteria. The results are shown in Table 1.

[0745] (Evaluation Criteria)

[0746] A: All 5 evaluators judged that the printed characters could be easily identified.

[0747] B: 1-4 evaluators judged that the printed words could be easily identified, while all other evaluators judged that although "A" was poor, the printed words could still be identified.

[0748] C: All 5 evaluators rated it as "A" (poor), but the printed characters were legible.

[0749] D: More than one evaluator judged that the printed characters could not be identified.

[0750] Evaluation of membranes used for protective film formation

[0751] <Evaluation of Printing Suitability and Printing Visibility>

[0752] Remove the first release film from the laminated film obtained above, and attach the exposed surface of the protective film forming film therefrom to the polished surface of the 8-inch silicon wafer, which is equivalent to the back side, in the same manner as described above. Then remove the second release film from the attached protective film forming film to obtain a second laminated body consisting of the protective film forming film and the silicon wafer.

[0753] Next, the second laminate is heated in an oven at 130°C for 2 hours to heat-cur the protective film, thus forming a protective film.

[0754] Next, the protective film in the second thermosetting laminate is directly irradiated with a laser from the outside of the protective film, opposite to the silicon wafer side, thereby printing text onto the protective film. The laser irradiation conditions are the same as those described above for forming a composite sheet using a protective film.

[0755] Next, for the second laminate with printed text, five evaluators directly observed the printed surface of the protective film from the outside of the protective film side of the second laminate. Then, the printability and print visibility of the protective film were evaluated according to the same criteria as above. The results are shown in Table 1.

[0756] Manufacturing and Evaluation of Support Sheets, Protective Film Forming Films, and Composite Sheets for Protective Film Forming

[0757] [Example 2]

[0758] When manufacturing the support sheet, a polypropylene film (2) (80 μm thick, colorless) of a different type than the polypropylene film (1) (thickness 80 μm, colorless, Young's modulus 510 MPa) was used instead of the polypropylene film (1) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 1 and evaluated.

[0759] For the polypropylene film (2), the Young's modulus was determined using the same method as in Example 1, and the result was 340 MPa.

[0760] The results are shown in Table 1.

[0761] [Example 3]

[0762] In manufacturing the support sheet, a non-energy-curable adhesive composition (I-4)-1 prepared using the method described below was used instead of the energy-curable adhesive composition (I-2)-1. Except for this, the support sheet, the protective film forming film, and the protective film forming composite sheet were manufactured and evaluated using the same method as in Example 2. The thickness of the adhesive layer was also the same as in Example 2, which was 5 μm.

[0763] The results are shown in Table 1.

[0764] <Preparation of Adhesive Composition (I-4)>

[0765] A non-energy-curable adhesive composition (I-4)-1 was prepared, comprising an adhesive resin (I-1a)-1 (100 parts by mass) and a hexamethylene diisocyanate crosslinking agent (“CORONATE HL” manufactured by TOSOH CORPORATION) (5 parts by mass), and further comprising methyl ethyl ketone as a solvent, wherein the total concentration of all components except the solvent is 25% by mass. Furthermore, the contents of components other than methyl ethyl ketone shown herein refer to the contents of the target substance excluding the solvent.

[0766] [Example 4]

[0767] When manufacturing the support sheet, a non-energy-curable adhesive composition (I-4)-2 prepared using the method shown below was used instead of the non-energy-curable adhesive composition (I-4)-1. Except for this, the support sheet, the protective film forming film, and the protective film forming composite sheet were manufactured using the same method as in Example 3, and then evaluated. The thickness of the adhesive layer was also the same as in Example 3, which was 5 μm.

[0768] The results are shown in Table 1.

[0769] <Preparation of Adhesive Composition (I-4)>

[0770] A non-energy-curable adhesive composition (I-4)-2 was prepared, comprising the adhesive resin (I-1a)-1 (100 parts by mass) and a trifunctional phthalimide diisocyanate crosslinking agent (TAKENATE D110N manufactured by Mitsui Takeda Chemical Co., Ltd.) (7 parts by mass), and further comprising methyl ethyl ketone as a solvent, wherein the total concentration of all components except the solvent is 25% by mass. Furthermore, the contents of components other than methyl ethyl ketone shown herein refer to the contents of the target substance excluding the solvent.

[0771] [Example 5]

[0772] In manufacturing the support sheet, a non-energy-curable adhesive composition (I-4)-3 prepared using the method described below was used instead of the energy-curable adhesive composition (I-2)-1. Except for this, the support sheet, the protective film forming film, and the protective film forming composite sheet were manufactured and evaluated using the same method as in Example 1. The thickness of the adhesive layer was also the same as in Example 1, which was 5 μm.

[0773] The results are shown in Table 1.

[0774] <Preparation of Adhesive Composition (I-4)>

[0775] A non-energy-curable adhesive composition (I-4)-3 was prepared, comprising an adhesive resin (I-1a)-2 (100 parts by mass) and a trifunctional phthalimide diisocyanate crosslinking agent (TAKENATE D110N manufactured by Mitsui Takeda Chemical Co., Ltd.) (18 parts by mass), and further comprising methyl ethyl ketone as a solvent, wherein the total concentration of all components except the solvent is 25% by mass. Furthermore, the contents of components other than methyl ethyl ketone shown herein refer to the contents of the target substance excluding the solvent.

[0776] The adhesive resin (I-1a)-2 is an acrylic polymer with a weight average molecular weight of 400,000, copolymerized from 2EHA (70 parts by mass), MMA (20 parts by mass) and HEA (10 parts by mass).

[0777] [Example 6]

[0778] When manufacturing the support sheet, a polypropylene film (3) (80 μm thick, blue), which is a different type from the polypropylene film (2) (thickness 80 μm, colorless, Young's modulus 510 MPa), was used instead of the polypropylene film (2) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 3, and evaluated.

[0779] For the polypropylene film (3), the Young's modulus was determined using the same method as in Example 1, and the result was 280 MPa.

[0780] The results are shown in Table 1.

[0781] [Example 7]

[0782] When manufacturing the support sheet, a polypropylene film (2) (80 μm thick, colorless, Young's modulus 340 MPa) was used instead of a polypropylene film (1) (80 μm thick, colorless, Young's modulus 510 MPa) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 5 and evaluated.

[0783] The results are shown in Table 1.

[0784] [Example 8]

[0785] When manufacturing the support sheet, a polypropylene film (3) (80 μm thick, blue, Young's modulus 280 MPa) was used instead of a polypropylene film (1) (80 μm thick, colorless, Young's modulus 510 MPa) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 5 and evaluated.

[0786] The results are shown in Table 1.

[0787] [Example 9]

[0788] When manufacturing the support sheet, a polypropylene film (1) (80 μm thick, colorless, Young's modulus 510 MPa) was used instead of a polypropylene film (2) (80 μm thick, colorless, Young's modulus 340 MPa) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 3, and were evaluated.

[0789] The results are shown in Table 1.

[0790] [Example 10]

[0791] When manufacturing the support sheet, a polypropylene film (1) (80 μm thick, colorless, Young's modulus 510 MPa) was used instead of a polypropylene film (2) (80 μm thick, colorless, Young's modulus 340 MPa) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 4, and were evaluated.

[0792] The results are shown in Table 1.

[0793] [Example 11]

[0794] When manufacturing the protective film forming film, a thermosetting protective film forming composition (III-1)-2 prepared by the method shown below was used instead of the thermosetting protective film forming composition (III-1)-1. Except for this, the support sheet, the protective film forming film, and the protective film forming composite sheet were manufactured using the same method as in Example 9, and then evaluated. The thickness of the protective film forming film was also the same as in Example 9, which was 15 μm.

[0795] The results are shown in Table 1.

[0796] <Preparation of the protective film forming composition (III-1)>

[0797] The polymer component (A)-1 (150 parts by mass), thermosetting components (B1)-1 (60 parts by mass), (B1)-2 (10 parts by mass), (B1)-3 (30 parts by mass), (B2)-1 (2 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (300 parts by mass), coupling agent (E)-1 (0.5 parts by mass), and colorant (I)-1 (4 parts by mass) 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 with a total concentration of 45% by mass for all components except the solvent. Furthermore, the amounts of components other than the mixed solvent shown here are the amounts of the target material excluding the solvent.

[0798] [Reference Example 1]

[0799] When manufacturing the protective film forming film, a thermosetting protective film forming composition (III-1)-3 prepared by the method shown below was used instead of the thermosetting protective film forming composition (III-1)-1. Except for this, the support sheet, the protective film forming film, and the protective film forming composite sheet were manufactured using the same method as in Example 9, and then evaluated. The thickness of the protective film forming film was also the same as in Example 9, which was 15 μm.

[0800] The results are shown in Table 1.

[0801] <Preparation of the protective film forming composition (III-1)>

[0802] The polymer component (A)-1 (150 parts by mass), thermosetting components (B1)-1 (60 parts by mass), (B1)-2 (10 parts by mass), (B1)-3 (30 parts by mass), (B2)-1 (2 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (300 parts by mass), coupling agent (E)-1 (0.5 parts by mass), and colorant (I)-1 (1 part by mass) 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 with a total concentration of 45% by mass for all components except the solvent. Furthermore, the amounts of components other than the mixed solvent shown here are the amounts of the target material excluding the solvent.

[0803] [Example 12]

[0804] When manufacturing the protective film forming film, a thermosetting protective film forming composition (III-1)-4 prepared by the method shown below was used instead of the thermosetting protective film forming composition (III-1)-1. Except for this, the support sheet, the protective film forming film, and the protective film forming composite sheet were manufactured using the same method as in Example 9, and then evaluated. The thickness of the protective film forming film was also the same as in Example 9, which was 15 μm.

[0805] The results are shown in Table 1.

[0806] <Preparation of the protective film forming composition (III-1)>

[0807] The polymer component (A)-1 (150 parts by mass), thermosetting components (B1)-1 (60 parts by mass), (B1)-2 (10 parts by mass), (B1)-3 (30 parts by mass), (B2)-1 (2 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (300 parts by mass), coupling agent (E)-1 (0.5 parts by mass), and colorant (I)-1 (30 parts by mass) 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 45% by mass for all components except the solvent. Furthermore, the amounts of components other than the mixed solvent shown here are the amounts of the target material excluding the solvent.

[0808] [Example 13]

[0809] When manufacturing the support sheet, polyethylene terephthalate film (1) (50 μm thick, colorless) was used instead of polypropylene film (3) (80 μm thick, blue, Young's modulus 280 MPa) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 6 and evaluated.

[0810] For the polyethylene terephthalate film (1), the Young's modulus was determined using the same method as in Example 1, and the result was 5000 MPa.

[0811] The results are shown in Table 1.

[0812] [Example 14]

[0813] When manufacturing the support sheet, a polyvinyl chloride film (1) (70 μm thick, black) was used instead of a polypropylene film (1) (80 μm thick, colorless, Young's modulus 510 MPa) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 12 and evaluated.

[0814] For the polyvinyl chloride film (1), the Young's modulus was determined using the same method as in Example 1, and the result was 400 MPa.

[0815] The results are shown in Table 1.

[0816] [Example 15]

[0817] When manufacturing the support sheet, except that a non-energy-curable adhesive composition (I-4)-4 prepared by the method shown below is used instead of a non-energy-curable adhesive composition (I-4)-1, and the thickness of the adhesive layer is set to 10 μm instead of 5 μm, the support sheet, the protective film forming film, and the protective film forming composite sheet are manufactured using the same method as in Example 6, and are evaluated.

[0818] The results are shown in Table 1.

[0819] <Preparation of Adhesive Composition (I-4)>

[0820] A non-energy-curable adhesive composition (I-4)-4 was prepared, comprising the adhesive resin (I-1a)-2 (100 parts by mass) and a trifunctional phthalimide diisocyanate crosslinking agent (TAKENATE D110N manufactured by Mitsui Takeda Chemical Co., Ltd.) (15 parts by mass), and further comprising methyl ethyl ketone as a solvent, wherein the total concentration of all components except the solvent is 25% by mass. Furthermore, the contents of components other than methyl ethyl ketone shown herein refer to the contents of the target substance excluding the solvent.

[0821] [Example 16]

[0822] When manufacturing the support sheet, except that the energy-ray curable adhesive composition (I-2)-2 prepared by the method shown below is used instead of the energy-ray curable adhesive composition (I-2)-1, and the thickness of the adhesive layer is set to 10 μm instead of 5 μm, the support sheet, the protective film forming film and the protective film forming composite sheet are manufactured using the same method as in Example 1, and are evaluated.

[0823] The results are shown in Table 1.

[0824] <Preparation of Adhesive Composition (I-2)>

[0825] An energy-curable adhesive composition (I-2)-2 was prepared, comprising the adhesive resin (I-2a)-1 (100 parts by mass), a trifunctional phthalimide diisocyanate crosslinking agent (TAKENATE D110N manufactured by Mitsui Takeda Chemical Co., Ltd.) (7 parts by mass), and a photopolymerization initiator (Irgacure 127 manufactured by BASF, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropane-1-one) (3 parts by mass), and further comprising methyl ethyl ketone as a solvent, wherein the total concentration of all components except the solvent is 25% by mass. Furthermore, the contents of components other than methyl ethyl ketone shown herein refer to the contents of the target substance excluding the solvent.

[0826] [Example 17]

[0827] When manufacturing the support sheet, except that the adhesive composition (I-2)-2 is used instead of the energy ray curable adhesive composition (I-2)-1, and the thickness of the adhesive layer is set to 10 μm instead of 5 μm, the support sheet, the protective film forming film, and the protective film forming composite sheet are manufactured using the same method as in Example 2, and then evaluated.

[0828] The results are shown in Table 1.

[0829] [Example 18]

[0830] When manufacturing the support sheet, the polyvinyl chloride film (1) (70 μm thick, black, Young's modulus 400 MPa) was used instead of the polypropylene film (2) (80 μm thick, colorless, Young's modulus 340 MPa) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 3, and evaluated.

[0831] The results are shown in Table 1.

[0832] [Comparative Example 1]

[0833] When manufacturing the support sheet, a polyvinyl chloride film (2) (70 μm thick, black) was used instead of a polypropylene film (2) (80 μm thick, colorless, Young's modulus 340 MPa) as the substrate. Except for this, the support sheet, the protective film forming film and the protective film forming composite sheet were manufactured using the same method as in Example 3 and evaluated.

[0834] For the polyvinyl chloride film (2), the Young's modulus was determined using the same method as in Example 1, and the result was 350 MPa.

[0835] The results are shown in Table 1.

[0836] [Example 19]

[0837] When manufacturing the protective film forming film, a thermosetting protective film forming composition (III-1)-5 prepared by the method shown below was used instead of the thermosetting protective film forming composition (III-1)-1. Except for this, the support sheet, the protective film forming film, and the protective film forming composite sheet were manufactured using the same method as in Example 1, and then evaluated. The thickness of the protective film forming film was also the same as in Example 1, which was 15 μm.

[0838] The results are shown in Table 1.

[0839] <Preparation of the protective film forming composition (III-1)>

[0840] The polymer component (A)-2 (150 parts by mass), thermosetting components (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 45% by mass for all components except the solvent. Furthermore, the amounts of components other than methyl ethyl ketone shown here refer to the content of the target substance excluding the solvent.

[0841] [Reference Example 2]

[0842] When manufacturing the protective film forming film, a thermosetting protective film forming composition (III-1)-6 prepared by the method shown below was used instead of the thermosetting protective film forming composition (III-1)-1. Except for this, the support sheet, the protective film forming film, and the protective film forming composite sheet were manufactured using the same method as in Example 1, and then evaluated. The thickness of the protective film forming film was also the same as in Example 1, which was 15 μm.

[0843] The results are shown in Table 1.

[0844] <Preparation of the protective film forming composition (III-1)>

[0845] The polymer component (A)-2 (150 parts by mass), thermosetting components (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 45% by mass for all components except the solvent. Furthermore, the amounts of components other than methyl ethyl ketone shown here are the amounts of the target material excluding the solvent.

[0846] [Comparative Example 2]

[0847] When manufacturing the protective film forming film, a thermosetting protective film forming composition (R1) prepared by the method shown below was used instead of the thermosetting protective film forming composition (III-1)-1. Except for this, the support sheet, the protective film forming film, and the protective film forming composite sheet were manufactured using the same method as in Example 1, and then evaluated. The thickness of the protective film forming film was also the same as in Example 1, which was 15 μm.

[0848] The results are shown in Table 1.

[0849] <Preparation of the protective film forming composition (R1)>

[0850] The polymer component (A)-2 (150 parts by mass), thermosetting components (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 45% by mass for all components except the solvent. Furthermore, the amounts of components other than methyl ethyl ketone shown here are the amounts of the target material excluding the solvent.

[0851] [Table 1]

[0852]

[0853] [Table 2]

[0854]

[0855] [Table 3]

[0856]

[0857] [Table 4]

[0858]

[0859] Based on the above results, it can be seen that in Examples 1 to 19, even when irradiated with lasers of shorter wavelengths than before, the printing suitability and visibility of the composite sheet for forming the protective film are good. In Examples 1 to 19, the transmittance of the support sheet to light (355nm) is 25% or more (25-91%), indicating high transmittance of the support sheet to light (355nm). On the other hand, the transmittance of the protective film for forming to light (355nm) is 59% or less (18-59%), indicating high absorption of the protective film for forming to light (355nm).

[0860] In Examples 1 to 17 and 19, the transmittance of the support sheet to light (355 nm) was higher than that of the film for forming the protective film to light (355 nm).

[0861] If we consider a single substrate, in Examples 1-19, its transmittance to light (355nm) is 26% or more (26-93%), indicating high transmittance to light (355nm) for a single substrate. Therefore, in terms of optical properties, it is suitable to fabricate these substrates into support sheets composed of substrates.

[0862] If we focus on the film used for forming a single protective film, then in Examples 1 to 19, the printability and print visibility are good.

[0863] The protective film forming film and the protective film exhibit approximately the same transmittance to light of the same wavelength. Therefore, the composite sheets for forming the protective film in Examples 1 to 19, even when the protective film forming film is not cured, exhibit the same characteristics as those that have been cured, and can be judged to have good printability and print visibility even when irradiated with a laser of a shorter wavelength than before.

[0864] In Reference Examples 1-2 and Comparative Example 2, when irradiated with a laser of a shorter wavelength than previously observed, the printability and visibility of the composite sheet used for forming the protective film were poor. In Reference Examples 1-2 and Comparative Example 2, the transmittance of the protective film to light (355 nm) was less than 62% (62-89%), indicating high transmittance at 355 nm. Therefore, in Reference Examples 1-2 and Comparative Example 2, although the transmittance of the support sheet to light (355 nm) was more than 89% (89-91%), indicating high transmittance at 355 nm, most of the laser light passed through the protective film, resulting in poor printability.

[0865] In Comparative Example 1, when irradiated with a laser of a shorter wavelength than before, the printability and print visibility of the composite sheet used to form the protective film were poor.

[0866] In Comparative Example 1, the protective film forming film had a light transmittance (355 nm) of 30%, indicating high light absorption (355 nm), which corresponds to the protective film forming film of one embodiment of the present invention described above. However, in Comparative Example 1, the support sheet had a light transmittance (355 nm) of 4%, indicating low light transmittance (355 nm). Therefore, in Comparative Example 1, the laser did not sufficiently reach the protective film through the support sheet, resulting in poor printability.

[0867] Based on the results of the above-described embodiments, reference examples, and comparative examples, it can be confirmed that: the transmittance of the support sheet to light (355nm) tends to be higher when the colorimetric degree of the support sheet (substrate, adhesive layer, etc.) is smaller; the content of components with aromatic cyclic groups such as benzene ring skeletons in the support sheet (substrate, adhesive layer, etc.) tends to be higher when the content of the support sheet (substrate, adhesive layer, etc.) is smaller; and the thickness of the support sheet (substrate, adhesive layer, etc.) tends to be higher when the thickness is thinner.

[0868] Industrial applicability

[0869] This invention can be used in the manufacture of semiconductor devices.

Claims

1. A protective film forming film having a transmittance of less than 35% for light with a wavelength of 355 nm. The protective film forming membrane contains polymer components, filler materials, and colorants. The polymer component is an acrylic polymer copolymerized from methyl acrylate and 2-hydroxyethyl acrylate, or an acrylic polymer copolymerized from methyl acrylate, methyl methacrylate, and 2-hydroxyethyl acrylate. The weight-average molecular weight of the polymer component is 100,000 to 400,000. In the protective film forming membrane, the content of the filler material relative to the total mass of the protective film forming membrane is 30-55% by mass. In the protective film forming film, the content of the colorant relative to the total mass of the protective film forming film is 3400 / 1143~12 by mass.

2. A composite sheet for forming a protective film, comprising a support sheet and a protective film forming film disposed on one surface of the support sheet. The support sheet has a transmittance of more than 20% for light with a wavelength of 355nm. The protective film forming membrane is the protective film forming membrane according to claim 1.

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

4. The composite sheet for forming a protective film according to claim 2 or 3, wherein, The composite sheet for forming the protective film is used to attach to the back side of the semiconductor wafer. In the semiconductor wafer, there is no through trench between the back side of the semiconductor wafer and the circuit forming surface opposite to the back side.

5. The composite sheet for forming a protective film according to claim 2 or 3, wherein, The composite sheet for forming the protective film is used to form a protective film at any location on the workpiece obtained by processing the workpiece. The protective film forming film is used to be attached to any position on the workpiece. When the protective film forming film is curable, the cured product of the protective film forming film is the protective film; when the protective film forming film is non-curable, the protective film forming film attached to any position on the workpiece is the protective film. The protective film forming composite sheet is used to: after attaching the protective film forming film in the protective film forming composite sheet to any position of the workpiece, and through the support sheet, irradiate the protective film forming film or protective film in the protective film forming composite sheet with a laser from the outside of the support sheet side of the protective film forming composite sheet, thereby printing words on the protective film forming film or protective film.

6. A method for manufacturing a workpiece with a protective film, wherein the manufacturing method comprises, The workpiece with protective film comprises a workpiece obtained by processing a workpiece and a protective film disposed at any position on the workpiece. The protective film is formed from the protective film forming film in any one of claims 2 to 5. When the protective film forming film is curable, the cured product of the protective film forming film is the protective film; when the protective film forming film is non-curable, the protective film forming film attached to any position on the workpiece is the protective film. The method for manufacturing the workpiece with the protective film includes the following steps: By attaching the protective film forming film in the protective film forming composite sheet to the target position of the workpiece, a first laminate having the protective film forming composite sheet disposed on the workpiece is produced in an attachment process. After the bonding process, a laser with a wavelength of 355 nm is irradiated onto the protective film forming film or protective film in the first laminate from the outside of the support sheet side of the protective film forming composite sheet, through the support sheet, thereby performing a printing process to print text on the protective film forming film or protective film; and The process of manufacturing the workpiece by processing the workpiece after the printing process is described. When the protective film forming film is curable, after the application step, there is a further curing step in which the protective film is formed by curing the protective film forming film.

7. A method for manufacturing a workpiece with a protective film, wherein the manufacturing method comprises, The workpiece with protective film comprises a workpiece obtained by processing a workpiece and a protective film disposed at any position on the workpiece. The protective film is formed from the protective film forming membrane as described in claim 1. When the protective film forming film is curable, the cured product of the protective film forming film is the protective film; when the protective film forming film is non-curable, the protective film forming film attached to any position on the workpiece is the protective film. The method for manufacturing the workpiece with the protective film includes the following steps: An attachment process is performed by attaching the protective film forming film to a target position on the workpiece, thereby creating a second laminate on the workpiece having the protective film forming film or the protective film disposed thereon. After the bonding process, a 355nm laser is directly irradiated onto the protective film forming film or protective film in the second laminate from the outside of the protective film forming film or protective film on the side opposite to the workpiece side, thereby performing a printing process to print characters on the protective film forming film or protective film; and The process of manufacturing the workpiece by processing the workpiece after the printing process is described. When the protective film forming film is curable, after the application step, there is a further curing step in which the protective film is formed by curing the protective film forming film.

8. Use of the support sheet and the protective film forming film according to claim 1 in the manufacture of a composite sheet for forming a protective film, wherein, The protective film forming membrane is disposed on one surface of the support sheet. The support sheet has a transmittance of more than 20% for light with a wavelength of 355nm. The composite sheet for forming the protective film is used to form a protective film at any location on the workpiece obtained by processing the workpiece. The protective film forming film is used to be attached to any position on the workpiece. When the protective film forming film is curable, the cured product of the protective film forming film is the protective film; when the protective film forming film is non-curable, the protective film forming film attached to any position on the workpiece is the protective film. The protective film forming composite sheet is used to: after attaching the protective film forming film in the protective film forming composite sheet to any position of the workpiece, and through the support sheet, irradiate the protective film forming film or protective film in the protective film forming composite sheet with a laser from the outside of the support sheet side of the protective film forming composite sheet, thereby printing words on the protective film forming film or protective film.

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