Protective film forming film, composite sheet for protective film forming, kit, and use of protective film forming film

Abstract

To provide an energy ray curable protective film-forming film that can be properly cured, and can manufacture a highly reliable chip with a protective film, in which peeling of the protective film is suppressed when the protective film-forming film is cured with energy rays, and a composite sheet for forming the protective film, a kit, and use of the film for forming the protective film.SOLUTION: In an energy ray curable protective film-forming film, the rate of change in indentation depth measured using a specific rate of change in indentation depth measurement method is 60% or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to protective film-forming films, composite sheets for protective film formation, kits, and the use of protective film-forming films. [Background technology]

[0002] Semiconductor wafers and insulating wafers have circuits formed on one side (the circuit side), and some of these wafers also have protruding electrodes such as bumps on that side (the circuit side). Such wafers are divided into chips, and the protruding electrodes are connected to connection pads on the circuit board by a so-called face-down method, thereby mounting them on the circuit board. In such wafers and chips, the side opposite the circuit surface (the back side) is sometimes protected with a protective film to suppress damage such as crack formation.

[0003] To form such a protective film, a protective film-forming film is attached to the back surface of the wafer. The protective film-forming film is laminated on a support sheet and may be used as a composite sheet for protective film formation, or it may be used without being laminated on a support sheet. After laser marking the protective film-forming film, the semiconductor wafer is divided into chips by dicing, and then picked up, after curing with heat or energy rays as necessary to enhance the protective performance of the protective film-forming layer. Alternatively, the protective film formed by curing the protective film-forming film with heat or energy rays is laser marked, and then the semiconductor wafer is divided into chips by dicing and picked up. Next, the picked-up semiconductor chips with protective films are flip-chip connected to connection pads on a circuit board such as a motherboard, and the protruding electrodes on the chips with protective films are melted by heating the circuit board (hereinafter referred to as the reflow process), strengthening the electrical connection between the protruding electrodes and the connection pads on the circuit board, and then mounted on the circuit board.

[0004] Some protective film-forming films are non-curable, meaning they do not harden and function as protective films in their current state. When using non-curable protective film-forming films, a hardening process is unnecessary, allowing for the manufacture of chips with protective films at a simplified and low-cost method. On the other hand, when using curable protective film-forming films, the hardened material serves as the protective film, offering the advantage of high wafer protection. Furthermore, while thermosetting protective film-forming films, which harden by heating, require a relatively long heating period for hardening, energy-ray curable protective film-forming films, which harden by energy ray irradiation, have the advantage of requiring only a short energy ray irradiation period for hardening. Therefore, various developments of energy-ray curable protective film-forming films are underway (see Patent Documents 1-3). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2010-031183 [Patent Document 2] International Publication No. 2017 / 188197 [Patent Document 3] International Publication No. 2019 / 082977 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, in conventional energy-ray curable protective film-forming films, even after energy-ray curing, the protective film-forming film may not cure sufficiently, resulting in the protective film being prone to peeling and insufficient adhesive strength and reliability. Thus, when the protective film-forming film is not properly cured, it can sometimes hinder the subsequent manufacturing of semiconductor devices.

[0007] The present invention aims to provide an energy-ray curable protective film-forming film that, when cured with energy rays, can be suitably cured and a highly reliable protective film-coated chip can be manufactured with suppressed peeling of the protective film, as well as a composite sheet, kit, and use of the protective film-forming film equipped therewith. [Means for solving the problem]

[0008] The present invention has the following aspects. [1] An energy ray curable protective film-forming film, A protective film-forming film wherein the rate of change in indentation depth, as measured by the method for measuring the rate of change in indentation depth of the protective film-forming film described below, is 60% or more. <Method for measuring the rate of change in indentation depth> Regarding the protective film forming film, the illuminance is 220 mW / cm². 2 , light intensity 500mJ / cm 2 Under these conditions, ultraviolet light with a wavelength of 365 nm is irradiated to produce a protective film after curing. The indentation depth (μm) of the protective film-forming film before and after curing is measured using an ultra-micro hardness tester under the following conditions. Indenter: Triangular pyramidal shape with a tip radius of curvature of 0.1 μm or less. Measurement mode: Load-unload test Maximum load: 10mN Holding time when maximum load is reached: 5 seconds Load speed: 0.14mN / sec Temperature: 23℃ Next, the difference between the indentation depth of the protective film-forming film after curing and the indentation depth of the protective film-forming film before curing is calculated using the following formula (1), and this is defined as the rate of change in the indentation depth of the protective film-forming film. The percentage change in indentation depth [%] = {(indentation depth of protective film before curing - indentation depth of protective film after curing) / indentation depth of protective film before curing} × 100 ... (1) [2] The protective film-forming film according to [1], which contains an acrylic resin (b) having no energy ray-curable group, and the acrylic resin (b) has a structural unit derived from 4-(meth)acryloylmorpholine. [3] A composite sheet for forming a protective film, comprising a support sheet and a protective film-forming film provided on one surface of the support sheet, The composite sheet for forming a protective film, wherein the protective film-forming film is the protective film-forming film according to [1] or [2]. [4] A kit comprising a first laminate in which a first release film and a protective film-forming film are laminated in this order, a work to which the protective film-forming film is to be adhered, and a support sheet used to support the protective film-forming film, The kit, wherein the protective film-forming film is the protective film-forming film according to [1] or [2]. [5] Use of a protective film-forming film for forming a protective film on a surface of a semiconductor wafer or semiconductor chip opposite to the circuit surface, Use of the protective film-forming film, wherein the protective film-forming film is the protective film-forming film according to [1] or [2].

Advantages of the Invention

[0009] According to the present invention, there are provided a protective film-forming film which is an energy ray-curable protective film-forming film and can be suitably cured when the protective film-forming film is cured by energy rays, and the peeling of the protective film is suppressed, a reliable chip with a protective film can be manufactured, a composite sheet for forming a protective film comprising the same, a kit, and use of the protective film-forming film.

Brief Description of the Drawings

[0010] [Figure 1] It is a cross-sectional view schematically showing an example of a protective film-forming film according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view schematically showing an example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 3] It is a cross-sectional view schematically showing another example of the composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 4] It is a cross-sectional view schematically showing still another example of the composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 5] It is a cross-sectional view schematically showing still another example of the composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 6] It is a cross-sectional view schematically showing an example of a kit according to an embodiment of the present invention. [Figure 7] It is a cross-sectional view for schematically explaining an example of a method for manufacturing a chip with a protective film according to an embodiment of the present invention. [Figure 8] It is a cross-sectional view for schematically explaining another example of a method for manufacturing a chip with a protective film according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0011] ◇Protective Film Forming Film The protective film forming film according to an embodiment of the present invention is an energy ray curable protective film forming film, The change rate of the indentation depth measured by the following method for measuring the change rate of the indentation depth of the protective film forming film is 60% or more. <Method for Measuring Change Rate of Indentation Depth> Regarding the protective film forming film, ultraviolet rays with a wavelength of 365 nm are irradiated under the conditions of an illuminance of 220 mW / cm 2 , and a light quantity of 500 mJ / cm 2 to produce a cured protective film forming film. Regarding the protective film forming film before and after curing, an ultra-micro hardness tester is used to measure the indentation depth (μm) under the following conditions. Indenter: Triangular pyramid with a tip curvature radius of 0.1 μm or less Measurement mode: Load-unload test Maximum load: 10 mN Holding time when the maximum load is reached: 5 seconds Loading speed: 0.14 mN / second Temperature: 23℃ Next, the difference between the indentation depth of the protective film-forming film after curing and the indentation depth of the protective film-forming film before curing is calculated using the following formula (1), and this is defined as the rate of change in the indentation depth of the protective film-forming film. The percentage change in indentation depth [%] = {(indentation depth of protective film before curing - indentation depth of protective film after curing) / indentation depth of protective film before curing} × 100 ... (1)

[0012] The protective film-forming film of this embodiment is a film used to protect a chip by providing a protective film on the back surface of the chip.

[0013] By using the protective film-forming film of this embodiment, or a composite sheet for forming a protective film equipped therewith, a chip with a protective film can be manufactured, comprising a chip and a protective film provided on the back surface of the chip. The aforementioned chip with a protective film can be manufactured, for example, by attaching a protective film-forming film to the back surface of a wafer, forming a protective film by curing the protective film-forming film, dividing the wafer into chips, and cutting the protective film along the outer circumference of the chips.

[0014] In this specification, "wafer" refers to semiconductor wafers composed of elemental semiconductors such as silicon, germanium, and selenium, or compound semiconductors such as GaAs, GaP, InP, CdTe, ZnSe, and SiC; and insulating wafers composed of insulators such as sapphire, glass, lithium niobate, and lithium tantalate. A circuit is formed on one side of these wafers, and in this specification, the side of the wafer on which the circuit is formed is referred to as the "circuit side." The side of the wafer opposite to the circuit side is referred to as the "back side." A wafer is divided into chips by means of dicing or other methods. In this specification, as with the wafer, the side of the chip on which the circuit is formed is referred to as the "circuit side," and the side of the chip opposite the circuit side is referred to as the "back side." Both the circuit surface of the wafer and the circuit surface of the chip are provided with protruding electrodes such as bumps and pillars. Preferably, these protruding electrodes are made of solder.

[0015] Furthermore, by using the aforementioned protective film-coated chip, a substrate device can be manufactured. In this specification, "substrate device" means a device configured such that a chip with a protective film is flip-chip connected to a connection pad on a circuit board at a protruding electrode on its circuit surface. For example, if a semiconductor wafer is used as the wafer, a semiconductor device can be considered a substrate device.

[0016] The protective film-forming film of this embodiment may be energy-ray curable and also thermosetting, or it may not be thermosetting. When the protective film-forming film of this embodiment has both energy-ray curable and thermosetting properties, the contribution of energy-ray curing of the protective film-forming film to the formation of the protective film is greater than the contribution of thermosetting.

[0017] In this specification, "energy beam" means an electromagnetic wave or charged particle beam that has an energy quantum. Examples of energy beams include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated, for example, by using high-pressure mercury lamps, fusion lamps, xenon lamps, black lights, or LED lamps as ultraviolet light sources. Electron beams can be irradiated using those generated by electron accelerators, etc. In this specification, "energy ray curable" means the property of hardening when irradiated with energy rays, and "non-energy ray curable" means the property of not hardening even when irradiated with energy rays. Furthermore, "non-curable" means that it does not harden by any means, such as heating or irradiation with energy rays.

[0018] The curing conditions when forming a protective film by energy ray curing of the protective film-forming film are not particularly limited as long as the degree of curing is sufficient for the protective film to fully perform its function, and can be appropriately selected depending on the type of protective film-forming film. For example, the illuminance of the energy rays during the energy ray curing of an energy ray-curable protective film is 60-320 mW / cm². 2 It is preferable that the amount of energy rays during curing is 100 to 1000 mJ / cm². 2 It is preferable that this be the case.

[0019] The protective film-forming film of this embodiment has a rate of change in indentation depth of 60% or more, as measured by the method for measuring the rate of change in indentation depth described below. <Method for measuring the rate of change in indentation depth> Regarding the protective film forming film, the illuminance is 220 mW / cm². 2 , light intensity 500mJ / cm 2 Under these conditions, ultraviolet light with a wavelength of 365 nm is irradiated to produce a protective film after curing. The indentation depth (μm) of the protective film-forming film before and after curing is measured using an ultra-micro hardness tester under the following conditions. Indenter: Triangular pyramidal shape with a tip radius of curvature of 0.1 μm or less. Measurement mode: Load-unload test Maximum load: 10mN Holding time when maximum load is reached: 5 seconds Load speed: 0.14mN / sec Temperature: 23℃ Next, the difference between the indentation depth of the protective film-forming film after curing and the indentation depth of the protective film-forming film before curing is calculated using the following formula (1), and this is defined as the rate of change in the indentation depth of the protective film-forming film. The percentage change in indentation depth [%] = {(indentation depth of protective film before curing - indentation depth of protective film after curing) / indentation depth of protective film before curing} × 100 ... (1)

[0020] By having a change rate of 60% or more in the indentation depth calculated by equation (1), the protective film-forming film can be suitably cured when the protective film-forming film is cured by energy rays, improving the adhesion of the protective film to the silicon wafer and suppressing the protective film from easily peeling off.

[0021] In the protective film forming film of this embodiment, the rate of change of the indentation depth determined by formula (1) is 60% or more. In order to suitably cure the protective film forming film, improve the adhesion of the protective film to the silicon wafer, and more suitably prevent the protective film from peeling off, the rate of change of the indentation depth determined by formula (1) is preferably 65% ​​or more, and more preferably 70% or more.

[0022] In order to suitably cure the protective film-forming film, improve the adhesion of the protective film to the silicon wafer, and more suitably prevent the protective film from peeling off, the indentation depth of the protective film-forming film before curing is preferably 8 μm or more, more preferably 10 μm or more, and even more preferably 12 μm or more.

[0023] To suitably cure the protective film-forming film, improve the adhesion of the protective film to the silicon wafer, and more suitably prevent the protective film from peeling off, the indentation depth of the cured protective film-forming film is preferably 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or less.

[0024] To suitably cure the protective film-forming film, improve the adhesion of the protective film to the silicon wafer, and more suitably prevent the protective film from peeling off, the peel strength of the cured protective film-forming film (protective film) is preferably 3.0 N / 10 mm or more, more preferably 4.0 N / 10 mm or more, and even more preferably 5.0 N / 10 mm or more. In this specification, the peel strength of the cured protective film (protective film) can be measured by the method described in the examples.

[0025] In order to suitably cure the protective film-forming film, improve the adhesion of the protective film to the silicon wafer, and more suitably prevent the protective film from peeling off, it is preferable that the peel strength of the cured protective film-forming film (protective film) is 500 N / 10 mm or less.

[0026] Examples of the protective film-forming film include one containing an energy ray-curable component (a) and an acrylic resin (b) that does not have energy ray-curable groups. The components of the protective film will be explained in detail later.

[0027] The protective film may consist of one layer (single layer) or of two or more layers. If the protective film consists of multiple layers, these layers may be identical or different, and the combination of these layers is not particularly limited.

[0028] In this specification, not only in the case of protective film-forming films, "multiple layers may be identical or different from one another" means "all layers may be identical, all layers may be different, or only some layers may be identical," and further, "multiple layers are different from one another" means "at least one of the constituent materials and thickness of each layer is different from the other."

[0029] The thickness of the protective film forming film is preferably 1 to 100 μm, more preferably 3 to 80 μm, and particularly preferably 5 to 60 μm. A protective film with a thickness equal to or greater than the lower limit can be formed. A protective film with a thickness equal to or less than the upper limit can be avoided, preventing the thickness of the protective film-coated chip from becoming excessive. Here, "thickness of protective film" refers to the total thickness of the protective film. For example, the thickness of a protective film consisting of multiple layers refers to the total thickness of all the layers that make up the protective film. In this specification, "thickness" can be determined by the method specified in JIS K 7130:1999 (ISO 4593:1993).

[0030] <<Composition for forming protective film>> A protective film can be formed using an energy-curable protective film-forming composition containing its constituent materials (in this specification, this may simply be referred to as "protective film-forming composition"). For example, a protective film can be formed by coating the surface to be formed with the protective film-forming composition and drying it as necessary. The ratio of components that do not vaporize at room temperature in the protective film-forming composition is usually the same as the ratio of those components in the protective film-forming film. In this specification, "room temperature" means a temperature that is not particularly cooled or heated, i.e., a normal temperature, such as 18 to 28°C.

[0031] The coating of the protective film-forming composition can be carried out by known methods, such as using various coaters including air knife coaters, blade coaters, bar coaters, gravure coaters, roll coaters, roll knife coaters, curtain coaters, die coaters, knife coaters, screen coaters, Meyer bar coaters, and kiss coaters.

[0032] The drying conditions for the protective film-forming composition are not particularly limited. However, if the protective film-forming composition contains a solvent as described later, it is preferable to heat-dry it. For example, a protective film-forming composition containing a solvent is preferably heat-dried at 70 to 130°C for 10 seconds to 5 minutes. However, for thermosetting protective film-forming compositions, it is preferable to heat-dry them in such a way that neither the composition itself nor the thermosetting protective film-forming film formed from it becomes thermosetting.

[0033] <Energy-ray curable protective film forming composition (IV)> Examples of preferred protective film-forming compositions include, for example, an energy-ray-curable protective film-forming composition (IV) (which may be simply referred to as "composition (IV)" in this specification) containing the energy-ray-curable component (a), an acrylic resin (b) that does not have the energy-ray-curable group, and the inorganic filler (d).

[0034] [Energy ray curing component (a)] The energy-ray curable component (a) is a component that hardens upon irradiation with energy rays. It imparts film-forming properties and flexibility to the protective film-forming film, and also forms a hard protective film after hardening. By containing the energy-ray curable component (a), the protective film-forming film forms a protective film with excellent properties. In the protective film, the energy ray curable component (a) is preferably uncured, preferably tacky, and more preferably both uncured and tacky.

[0035] Examples of the energy-ray curable component (a) include a polymer (a1) having an energy-ray curable group and a weight-average molecular weight of 80,000 to 2,000,000, and a compound (a2) having an energy-ray curable group and a molecular weight of 100 to 80,000. The polymer (a1) may be at least partially crosslinked with a crosslinking agent, or it may not be crosslinked.

[0036] (a1) A polymer having energy-ray curable groups and a weight-average molecular weight of 80,000 to 2,000,000. Examples of polymers (a1) having energy-ray curable groups and a weight-average molecular weight of 80,000 to 2,000,000 include an acrylic resin (a1-1) obtained by reacting an acrylic polymer (a11) having a functional group that can react with a group that has been found in other compounds with an energy-ray curable compound (a12) having a group that reacts with the functional group and an energy-ray curable group such as an energy-ray curable double bond.

[0037] Examples of functional groups that can react with groups of other compounds include hydroxyl groups, carboxyl groups, amino groups, substituted amino groups (groups having a structure in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom), and epoxy groups. However, in terms of preventing corrosion of circuits such as wafers and chips, it is preferable that the functional group is a group other than a carboxyl group. Among these, the functional group is preferably a hydroxyl group.

[0038] • Acrylic polymer having functional groups (a11) Examples of the acrylic polymer (a11) having the functional group include those obtained by copolymerizing an acrylic monomer having the functional group with an acrylic monomer not having the functional group, and those obtained by copolymerizing monomers other than acrylic monomers (non-acrylic monomers) in addition to these monomers. Furthermore, the acrylic polymer (a11) may be a random copolymer or a block copolymer, and known polymerization methods can be used.

[0039] Examples of acrylic monomers having the functional group include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, substituted amino group-containing monomers, epoxy group-containing monomers, and the like.

[0040] Examples of the hydroxyl group-containing monomers include hydroxyalkyl (meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; and non-(meth)acrylic unsaturated alcohols (unsaturated alcohols that do not have a (meth)acryloyl skeleton) such as vinyl alcohol and allyl alcohol.

[0041] Examples of the carboxyl group-containing monomers include ethylenically unsaturated monocarboxylic acids (monocarboxylic acids having an ethylenically unsaturated bond) such as (meth)acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids (dicarboxylic acids having an ethylenically unsaturated bond) such as fumaric acid, itaconic acid, maleic acid, and citraconic acid; anhydrides of the ethylenically unsaturated dicarboxylic acids; and carboxyalkyl esters of (meth)acrylic acid such as 2-carboxyethyl methacrylate.

[0042] The acrylic monomer having the aforementioned functional group is preferably a monomer containing a hydroxyl group.

[0043] The acrylic polymer (a11) may consist of only one acrylic monomer having the functional group, or it may consist of two or more types. If there are two or more types, their combination and ratio can be arbitrarily selected.

[0044] Examples of acrylic monomers that do not have the aforementioned functional groups include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and i Examples of alkyl esters include sononyl, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl ((meth)acrylate) (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl ((meth)acrylate) (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl ((meth)acrylate) (palmityl (meth)acrylate), heptadecyl (meth)acrylate, octadecyl ((meth)acrylate) (stearyl (meth)acrylate), etc., in which the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms.

[0045] Furthermore, examples of acrylic monomers that do not have the aforementioned functional groups include alkoxyalkyl group-containing (meth)acrylic acid esters such as methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and ethoxyethyl (meth)acrylate; aromatic group-containing (meth)acrylic acid esters such as aryl (meth)acrylate such as phenyl (meth)acrylate; non-crosslinked (meth)acrylamides and their derivatives; and non-crosslinked (meth)acrylic acid esters having tertiary amino groups such as N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

[0046] The acrylic polymer (a11) may consist of only one acrylic monomer that does not have the functional group, or it may consist of two or more types. If there are two or more types, their combination and ratio can be arbitrarily selected.

[0047] Examples of the non-acrylic monomers include olefins such as ethylene and norbornene; vinyl acetate; and styrene. The non-acrylic monomers constituting the acrylic polymer (a11) may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0048] In the acrylic polymer (a11), the ratio (content) of the amount of constituent units derived from the functional group-containing acrylic monomer to the total amount of constituent units is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass, and particularly preferably 3 to 30% by mass. Having this ratio within this range allows the content of energy-ray-curable groups in the acrylic resin (a1-1) obtained by copolymerization of the acrylic polymer (a11) and the energy-ray-curable compound (a12) to be adjusted to a preferred range for the degree of curing of the protective film.

[0049] The acrylic polymer (a11) constituting the acrylic resin (a1-1) may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0050] In the protective film-forming film, the ratio of the acrylic resin (a1-1) content to the total mass of the protective film-forming film is preferably 1 to 70% by mass, more preferably 5 to 60% by mass, and particularly preferably 10 to 50% by mass.

[0051] • Energy ray curable compound (a12) The energy-ray curable compound (a12) preferably has one or more groups selected from the group consisting of isocyanate groups, epoxy groups, and carboxyl groups as groups that can react with the functional groups of the acrylic polymer (a11), and more preferably has an isocyanate group as the group. For example, if the energy-ray curable compound (a12) has an isocyanate group as the group, this isocyanate group readily reacts with the hydroxyl group of the acrylic polymer (a11) having a hydroxyl group as the functional group.

[0052] The number of energy-ray curable groups in one molecule of the energy-ray curable compound (a12) is not particularly limited and can be appropriately selected, for example, by considering physical properties such as shrinkage rate required for the target protective film. For example, the energy ray curable compound (a12) preferably has 1 to 5 energy ray curable groups in one molecule, and more preferably 1 to 3.

[0053] Examples of the energy-ray curable compound (a12) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate; Acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth)acrylate; Examples include acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate. Among these, the energy ray curable compound (a12) is preferably 2-methacryloyloxyethyl isocyanate.

[0054] The energy ray curable compound (a12) constituting the acrylic resin (a1-1) may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0055] In the acrylic resin (a1-1), the ratio of the content of energy-ray-curable groups derived from the energy-ray-curable compound (a12) to the content of the functional groups derived from the acrylic polymer (a11) is preferably 20 to 120 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. Having the content within this range increases the adhesive strength of the cured protective film. Note that if the energy-ray-curable compound (a12) is a monofunctional compound (having one of the groups in one molecule), the upper limit of the content ratio is 100 mol%, but if the energy-ray-curable compound (a12) is a polyfunctional compound (having two or more of the groups in one molecule), the upper limit of the content ratio may exceed 100 mol%.

[0056] The weight-average molecular weight (Mw) of the polymer (a1) is preferably 100,000 to 2,000,000, and more preferably 300,000 to 1,500,000.

[0057] In this specification, "weight-average molecular weight" refers to the polystyrene equivalent value measured by gel permeation chromatography (GPC) unless otherwise specified.

[0058] The polymer (a1) contained in composition (IV) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0059] (a2) Compounds having energy-ray curable groups and a molecular weight of 100 to 80,000) In compound (a2) having an energy-ray curable group and a molecular weight of 100 to 80000, the energy-ray curable group can be a group containing an energy-ray curable double bond, and preferred examples include a (meth)acryloyl group and a vinyl group.

[0060] The compound (a2) is not particularly limited as long as it satisfies the above conditions, but examples include low molecular weight compounds having energy ray curable groups, epoxy resins having energy ray curable groups, and phenolic resins having energy ray curable groups.

[0061] Among the compounds (a2) mentioned above, examples of low molecular weight compounds having an energy-ray curable group include polyfunctional monomers or oligomers, and acrylate compounds having a (meth)acryloyl group are preferred.

[0062] Examples of the acrylate compounds include polyfunctional monomers or oligomers, and polyfunctional acrylate compounds having two or more (meth)acryloyl groups in one molecule are preferred. Examples of the aforementioned polyfunctional acrylate compounds include 2-hydroxy-3-(meth)acryloyloxypropyl methacrylate, polyethylene glycol di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxypolyethoxy)phenyl]propane, ethoxylated bisphenol A di(meth)acrylate, 2,2-bis[4-((meth)acryloxydiethoxy)phenyl]propane, 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene, 2,2-bis[4-((meth)acryloxypolypropoxy)phenyl]propane, tricyclodecanedimethanol di(meth)acrylate (also known as tricyclodecanedimethylol di(meth)acrylate), 1,10-decanediol di(meth)acrylate, 1, Difunctional (meth)acrylates such as 6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2-bis[4-((meth)acryloxyethoxy)phenyl]propane, neopentyl glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, and 2-hydroxy-1,3-di(meth)acryloxypropane (meth)acrylates having two (meth)acryloyl groups in one molecule); Polyfunctional (meth)acrylates such as tris(2-(meth)acryloyl) isocyanurate, ε-caprolactone-modified tris-(2-(meth)acryloyl) isocyanurate, ethoxylated glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, and dipentaerythritol hexa(meth)acrylate (meth)acrylates having three or more (meth)acryloyl groups in one molecule); Examples include polyfunctional (meth)acrylate oligomers such as polyfunctional urethane (meth)acrylate oligomers (meth)acrylate oligomers having two or more (meth)acryloyl groups in one molecule).

[0063] Among the compounds (a2) mentioned above, epoxy resins and phenolic resins having energy-ray curable groups can be, for example, those described in paragraph 0043 of "Japanese Patent Publication No. 2013-194102," etc. Such resins also fall under the category of resins constituting the thermosetting components described later, but in composition (IV), they are treated as compounds (a2).

[0064] The weight-average molecular weight of compound (a2) is preferably 100 to 30,000, and more preferably 300 to 10,000.

[0065] The compound (a2) contained in composition (IV) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0066] The protective film preferably contains the compound (a2) as the energy-curable component (a), more preferably a polyfunctional acrylate compound having two or more (meth)acryloyl groups in one molecule, and even more preferably a polyfunctional urethane (meth)acrylate oligomer. The cured product (protective film) of such a protective film containing the energy-curable component (a) by energy irradiation has good protective ability while also being flexible, and has particularly excellent properties.

[0067] When composition (IV) and the protective film-forming film contain an energy ray curable component (a), the content of the energy ray curable component (a) in composition (IV) and the protective film-forming film is preferably 100 to 310 parts by mass, more preferably 130 to 280 parts by mass, based on 100 parts by mass of the acrylic resin (b). For example, it may be 130 to 200 parts by mass or 210 to 280 parts by mass.

[0068] In composition (IV), the ratio of the energy ray curable component (a) to the total content of all components other than the solvent (i.e., the ratio of the energy ray curable component (a) content to the total mass of the protective film-forming film in the protective film-forming film) is preferably 12 to 31% by mass, more preferably 14 to 28% by mass, and even more preferably 16 to 25% by mass. When the ratio of the energy ray curable component (a) (i.e., the ratio of the energy ray curable component (a) content) is above the lower limit, the energy ray curability of the protective film-forming film is improved. When the ratio of the energy ray curable component (a) (i.e., the ratio of the energy ray curable component (a) content) is below the upper limit, it is easier to prepare the desired protective film-forming film.

[0069] [Acrylic resin without energy-ray curable groups (b)] The protective film preferably contains an acrylic resin (b) that does not have energy-ray curable groups (in this specification, it may be simply referred to as "acrylic resin (b)").

[0070] The acrylic resin (b) is a component that imparts film-forming properties to the protective film-forming film.

[0071] The acrylic resin (b) may be any known material, for example, a homopolymer of one acrylic monomer, a copolymer of two or more acrylic monomers, or a copolymer of one or more acrylic monomers and one or more monomers other than acrylic monomers (non-acrylic monomers).

[0072] The acrylic resin (b) preferably has structural units derived from 4-(meth)acryloylmorpholine. That is, the acrylic resin (b) preferably is a polymer of 4-(meth)acryloylmorpholine. The presence of structural units derived from 4-(meth)acryloylmorpholine in the acrylic resin (b) results in excellent adhesion to the wafer or chip and a higher effect in suppressing the peeling of the protective film from the wafer or chip.

[0073] The acrylic resin (b) preferably has a constituent unit derived from 4-(meth)acryloylmorpholine and other constituent units. That is, the acrylic resin (b) is preferably a copolymer of 4-(meth)acryloylmorpholine and other monomers or oligomers.

[0074] In the acrylic resin (b), the ratio of the amount of constituent units derived from 4-(meth)acryloylmorpholine to the total amount of constituent units is preferably 10 to 30% by mass, more preferably 13 to 30% by mass, and may be any of 18 to 30% by mass or 23 to 30% by mass.

[0075] The acrylic resin (b) may be crosslinked with a crosslinking agent in at least a portion of it, or it may not be crosslinked.

[0076] Examples of acrylic monomers constituting the acrylic resin (b) include (meth)acrylic acid esters such as alkyl (meth)acrylates, (meth)acrylates having a cyclic skeleton but no functional groups, glycidyl group-containing (meth)acrylates, hydroxyl group-containing (meth)acrylates, substituted amino group-containing (meth)acrylates, carboxyl group-containing (meth)acrylates, and amino group-containing (meth)acrylates; (meth)acrylamides; and (meth)acrylamide derivatives such as 4-(meth)acryloylmorpholine. Here, "substituted amino group" means a group having a structure in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom. Here, "functional group" means a group that can react with other groups (reactive functional group), such as a glycidyl group, hydroxyl group, substituted amino group, carboxyl group, and amino group.

[0077] In this specification, "(meth)acrylic acid" is a concept that encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid; for example, "(meth)acrylate" is a concept that encompasses both "acrylate" and "methacrylate," and "(meth)acryloyl group" is a concept that encompasses both "acryloyl group" and "methacryloyl group."

[0078] In this specification, when a particular compound is assumed to have a structure in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms, a compound having such a substituted structure will be referred to as a "derivative" of the particular compound described above. In this specification, the term "group" includes not only atomic groups formed by the bonding of multiple atoms, but also single atoms.

[0079] Examples of alkyl (meth)acrylate esters that do not have the aforementioned functional group and cyclic skeleton include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and (meth Examples include alkyl esters such as isononyl acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl ((meth)acrylate) (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl ((meth)acrylate) (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl ((meth)acrylate) (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl ((meth)acrylate) (stearyl (meth)acrylate), in which the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms.

[0080] Examples of (meth)acrylic acid esters that do not have the aforementioned functional groups and have a cyclic skeleton include cycloalkyl (meth)acrylic acid esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (meth)acrylate aralkyl esters such as benzyl (meth)acrylate; (meth)acrylate dicyclopentenyl ester and other cycloalkenyl (meth)acrylates; Examples include cycloalkenyloxyalkyl esters of (meth)acrylate, such as dicyclopentenyloxyethyl (meth)acrylate.

[0081] Examples of the glycidyl group-containing (meth)acrylic acid ester include glycidyl (meth)acrylate. Examples of the hydroxyl group-containing (meth)acrylic acid ester include alkyl (meth)acrylic acid esters that do not have the functional group and a cyclic skeleton, and (meth)acrylic acid esters that do not have the functional group but have a cyclic skeleton, in which one or more hydrogen atoms are substituted with hydroxyl groups. Preferred examples of the hydroxyl group-containing (meth)acrylic acid ester include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of the substituted amino group-containing (meth)acrylic acid ester include N-methylaminoethyl (meth)acrylate.

[0082] Examples of non-acrylic monomers constituting the acrylic resin (b) include olefins such as ethylene and norbornene; vinyl acetate; styrene, etc.

[0083] Examples of acrylic resins (b) that are crosslinked by a crosslinking agent include those in which the functional groups in acrylic resin (b) react with the crosslinking agent. The functional group can be appropriately selected depending on the type of crosslinking agent, etc., and is not particularly limited. For example, when the crosslinking agent is a polyisocyanate compound, the functional group can be a hydroxyl group, a carboxyl group, an amino group, etc., and among these, the hydroxyl group, which has high reactivity with isocyanate groups, is preferred. When the crosslinking agent is an epoxy compound, the functional group can be a carboxyl group, an amino group, etc., and among these, the carboxyl group, which has high reactivity with epoxy groups, is preferred. However, in terms of preventing corrosion of wafer and chip circuits, it is preferable that the functional group is a group other than a carboxyl group.

[0084] Examples of the acrylic resin (b) having the functional group include those obtained by polymerizing at least one monomer having the functional group. More specifically, the acrylic resin (b) having the functional group can be obtained by polymerizing one or more monomers selected from the group consisting of the glycidyl group-containing (meth)acrylic acid ester, the hydroxyl group-containing (meth)acrylic acid ester, the substituted amino group-containing (meth)acrylic acid ester, the carboxyl group-containing (meth)acrylic acid ester, the amino group-containing (meth)acrylic acid ester, and monomers having a structure in which one or more hydrogen atoms in the non-acrylic monomer are substituted with the functional group.

[0085] In the acrylic resin (b), the ratio (content) of the amount of constituent units derived from monomers having functional groups to the total amount of constituent units is preferably 1 to 20% by mass, and more preferably 2 to 10% by mass. When the ratio is within this range, the degree of crosslinking in the acrylic resin (b) is within a more preferable range.

[0086] The weight-average molecular weight (Mw) of acrylic resin (b) is preferably 10,000 or more, more preferably 20,000 or more, and even more preferably 40,000 or more, from the viewpoint of further suppressing bleed-out during the reflow process. The weight-average molecular weight (Mw) of acrylic resin (b) is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000, from the viewpoint of improving the film-forming properties of composition (IV).

[0087] The acrylic resin (b) contained in composition (IV) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0088] In composition (IV), the ratio of the content of acrylic resin (b) to the total content of all components other than the solvent (i.e., the ratio of the content of acrylic resin (b) to the total mass of the protective film in the protective film-forming film) is preferably 8% by mass or more, more preferably 10% by mass or more, and may be, for example, 12% by mass or more, or 14% by mass or more.

[0089] In composition (IV), the upper limit of the ratio of the acrylic resin (b) content to the total content of all components other than the solvent (i.e., the ratio of the acrylic resin (b) content to the total mass of the protective film-forming film in the protective film-forming film) is not particularly limited. In order for the protective film to exhibit a good balance between the property of suppressing bleed-out due to the reflow process and other properties, the upper limit may be 27% by mass or less, preferably 25% by mass or less, more preferably 23% by mass or less, and even more preferably 21% by mass or less.

[0090] In composition (IV), the ratio of the acrylic resin (b) content to the total content of all components other than the solvent (i.e., the ratio of the acrylic resin (b) content to the total mass of the protective film in the protective film-forming film) can be appropriately adjusted within a range set by any combination of the lower and upper limits described above. For example, in one embodiment, the proportion is preferably 8 to 27% by mass, more preferably 10 to 25% by mass, and may be any of 12 to 23% by mass or 14 to 21% by mass.

[0091] When composition (IV) and protective film-forming film contain an energy ray-curable component (a) and an acrylic resin (b), the content of the energy ray-curable component (a) in composition (IV) and protective film-forming film is preferably 70 to 310 parts by mass, more preferably 80 to 280 parts by mass, and even more preferably 85 to 250 parts by mass, based on 100 parts by mass of the acrylic resin (b).

[0092] In composition (IV), the ratio of the total content of the energy ray-curable component (a) and the acrylic resin (b) to the total content of all components other than the solvent (i.e., the ratio of the total content of the energy ray-curable component (a) and the acrylic resin (b) to the total mass of the protective film-forming film) is preferably 10 to 60% by mass, and may be, for example, 20 to 50% by mass and 30 to 45% by mass. Having the ratio within this range enhances the effects of using the energy ray-curable component (a) and the acrylic resin (b).

[0093] [Other ingredients] Composition (IV) and the protective film-forming film may contain other components that do not fall under either the energy ray-curable component (a) or the acrylic resin (b), as long as they do not impair the effects of the present invention. Examples of the other components mentioned above include photopolymerization initiators (c), inorganic fillers (d), coupling agents (e), crosslinking agents (f), colorants (g), thermosetting components (h), general-purpose additives (z), and polymers (b0) that do not fall under the category of acrylic resin (b) and do not have energy-ray curable groups (in this specification, these may be referred to as "other polymers (b0) that do not have energy-ray curable groups" or "polymer (b0)").

[0094] (Photopolymerization initiator (c)) When composition (IV) and the protective film contain a photopolymerization initiator (c), the polymerization (curing) reaction of the energy ray-curable component (a) can be efficiently promoted.

[0095] Examples of the photopolymerization initiators include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal; acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one, and 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone; and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxy Examples include acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; sulfide compounds such as benzylphenyl sulfide and tetramethylthiuram monosulfide; α-ketol compounds such as 1-hydroxycyclohexylphenyl ketone; azo compounds such as azobisisobutyronitrile; titanocene compounds such as titanocene; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as diacetyl; benzyl; dibenzyl; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; and quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone. Furthermore, examples of photopolymerization initiators include photosensitizers such as amines.

[0096] The photopolymerization initiator (c) contained in composition (IV) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. For example, a highly reactive photopolymerization initiator that is liquid at room temperature, such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, can be used alone to efficiently crosslink the protective film-forming film and increase the gel fraction. A less reactive photopolymerization initiator, such as 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one or 1-hydroxycyclohexyl-phenyl ketone, can be used in combination with a highly reactive photopolymerization initiator such as 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone to efficiently crosslink the protective film-forming film and increase the gel fraction.

[0097] When a photopolymerization initiator (c) is used, the content of the photopolymerization initiator (c) in composition (IV) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and particularly preferably 2 to 5 parts by mass, based on the content of 100 parts by mass of the energy ray curable component (a).

[0098] (Inorganic filler (d)) When composition (IV) and the protective film-forming film contain inorganic filler (d), the coefficient of thermal expansion of the cured product of the protective film-forming film (e.g., protective film) can be more easily adjusted by adjusting the amount of inorganic filler (d) in composition (IV) and the protective film-forming film. For example, optimizing the coefficient of thermal expansion of the protective film for the object on which the protective film is formed further improves the reliability of the package obtained using the protective film-forming film. Furthermore, by using a protective film-forming film containing inorganic filler (d), it is also possible to reduce the moisture absorption rate or improve the heat dissipation of the cured product of the protective film-forming film (e.g., protective film).

[0099] Examples of inorganic fillers (d) include powders of inorganic materials such as silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride; beads formed from these inorganic materials in a spherical shape; surface-modified products of these inorganic materials; single-crystal fibers of these inorganic materials; and glass fibers. Among these, the inorganic filler (d) is preferably silica or alumina.

[0100] The inorganic filler (d) contained in composition (IV) and the protective film-forming film may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0101] In composition (IV), the ratio of the inorganic filler (d) content to the total content of all components other than the solvent (i.e., the ratio of the inorganic filler (d) content to the total mass of the protective film in the protective film-forming film) is preferably 35 to 75% by mass, and may be, for example, 45 to 70% by mass and 50 to 65% by mass. By having the ratio within this range, the effect of using the inorganic filler (d) is enhanced without impairing the properties of the protective film-forming film.

[0102] (Coupling agent (e)) When composition (IV) and the protective film-forming film contain a coupling agent (e) having a functional group that can react with an inorganic or organic compound, the adhesion and bonding of the protective film-forming film to the adherend are improved. Furthermore, the cured product of the protective film-forming film (e.g., protective film) exhibits improved water resistance without impairing heat resistance.

[0103] The coupling agent (e) is preferably a compound having a functional group that can react with the functional groups of the acrylic resin (b), the energy ray curable component (a), etc., and is more preferably a silane coupling agent. Preferred silane coupling agents include, for example, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- Examples include aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfan, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane.

[0104] The coupling agent (e) contained in composition (IV) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0105] When a coupling agent (e) is used, the content of the coupling agent (e) in composition (IV) and the protective film is preferably 0.03 to 20 parts by mass per 100 parts by mass of the total content of the energy ray curable component (a) and the acrylic resin (b). When the content of the coupling agent (e) is above the lower limit, the effects of using the coupling agent (e) are more pronounced, such as improved dispersibility of the inorganic filler (d) in the resin and improved adhesion of the protective film to the adherend. When the content of the coupling agent (e) is below the upper limit, outgassing is further suppressed.

[0106] (Crosslinking agent (f)) When using an acrylic resin (b) that has functional groups such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups that can bond with other compounds, composition (IV) and the protective film-forming film may contain a crosslinking agent (f). The crosslinking agent (f) is a component for crosslinking the functional groups in the acrylic resin (b) with other compounds, and by crosslinking in this way, the initial adhesive strength and cohesive strength of the protective film-forming film can be adjusted.

[0107] Examples of crosslinking agents (f) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridinyl group).

[0108] Examples of the aforementioned organic polyvalent isocyanate compounds include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, and alicyclic polyvalent isocyanate compounds (hereinafter, these compounds may be collectively abbreviated as "aromatic polyvalent isocyanate compounds, etc."); trimers, isocyanurates, and adducts of the aforementioned aromatic polyvalent isocyanate compounds, etc.; and terminal isocyanate urethane prepolymers obtained by reacting the aforementioned aromatic polyvalent isocyanate compounds, etc. with polyol compounds. The aforementioned "adduct" refers to the reaction product of the aromatic polyvalent isocyanate compound, aliphatic polyvalent isocyanate compound, or alicyclic polyvalent isocyanate compound with a low molecular weight active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, or castor oil. Examples of the aforementioned adduct include the xylylene diisocyanate adduct of trimethylolpropane, as described later. Furthermore, "terminal isocyanate urethane prepolymer" refers to a prepolymer that has urethane bonds and isocyanate groups at the ends of the molecule.

[0109] More specifically, examples of the aforementioned organic polyvalent isocyanate compounds include, for example, 2,4-tolylene diisocyanate; 2,6-tolylene diisocyanate; 1,3-xylylene diisocyanate; 1,4-xylylene diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; compounds in which one or more of tolylene diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are added to all or some of the hydroxyl groups of polyols such as trimethylolpropane; and lysine diisocyanate.

[0110] Examples of the aforementioned organic polyvalent imine compounds include N,N'-diphenylmethane-4,4'-bis(1-aziridinylcarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, and N,N'-toluene-2,4-bis(1-aziridinylcarboxamide)triethylenemelamine.

[0111] When an organic polyvalent isocyanate compound is used as the crosslinking agent (f), it is preferable to use a hydroxyl group-containing polymer as the acrylic resin (b). When the crosslinking agent (f) has an isocyanate group and the acrylic resin (b) has a hydroxyl group, a crosslinked structure can be easily introduced into the protective film by the reaction between the crosslinking agent (f) and the acrylic resin (b).

[0112] The crosslinking agent (f) contained in composition (IV) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0113] When using a crosslinking agent (f), the content of the crosslinking agent (f) in composition (IV) is preferably 0.01 to 20 parts by mass per 100 parts by mass of acrylic resin (b). When the content of the crosslinking agent (f) is above the lower limit, the effect of using the crosslinking agent (f) is more pronounced. When the content of the crosslinking agent (f) is below the upper limit, the overuse of the crosslinking agent (f) is suppressed.

[0114] (Coloring agent (g)) If composition (IV) and the protective film-forming film contain a coloring agent (g), the light transmittance of the protective film-forming film can be adjusted by adjusting the amount of the coloring agent. By adjusting the light transmittance in this way, for example, the visibility of laser marks when laser marking is performed on the protective film-forming film or protective film can be adjusted. It is also possible to improve the aesthetic appearance of the protective film or to make grinding marks on the back surface of the wafer less visible.

[0115] Examples of colorants (g) include known ones such as inorganic pigments, organic pigments, and organic dyes.

[0116] Examples of the aforementioned organic pigments and organic dyes include aminium-based dyes, cyanine-based dyes, merocyanine-based dyes, croconium-based dyes, squalium-based dyes, azulenium-based dyes, polymethine-based dyes, naphthoquinone-based dyes, pyririum-based dyes, phthalocyanine-based dyes, naphthalocyanine-based dyes, naphtholactam-based dyes, azo-based dyes, condensed azo-based dyes, indigo-based dyes, perinone-based dyes, perylene-based dyes, dioxazine-based dyes, quinacridone-based dyes, isoindolone-based dyes, quinophthalone-based dyes, pyrrole-based dyes, thioindigo-based dyes, metal complex-based dyes (metal complex salt dyes), dithiol metal complex-based dyes, indolephenol-based dyes, triallylmethane-based dyes, anthraquinone-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyranthrone-based dyes, and surene-based dyes.

[0117] Examples of the inorganic pigments mentioned above include carbon black, cobalt-based dyes, iron-based dyes, chromium-based dyes, titanium-based dyes, vanadium-based dyes, zirconium-based dyes, molybdenum-based dyes, ruthenium-based dyes, platinum-based dyes, ITO (indium tin oxide)-based dyes, ATO (antimony tin oxide)-based dyes, and the like.

[0118] The colorants (g) contained in composition (IV) and the protective film may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0119] When using a coloring agent (g), the content of the coloring agent (g) in composition (IV) and the protective film-forming film can be appropriately adjusted according to the purpose. For example, as described above, when improving the visibility of laser marks on the protective film-forming film or protective film, or the design of the protective film, or when making grinding marks on the back surface of the wafer less visible, the ratio of the content of the coloring agent (g) to the total content of all components other than the solvent in composition (IV) (i.e., the ratio of the content of the coloring agent (g) to the total mass of the protective film-forming film in the 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. When the ratio is above the lower limit, the effect of using the coloring agent (g) is more pronounced. When the ratio is below the upper limit, excessive use of the coloring agent (g) is suppressed.

[0120] (Thermosetting component (h)) When composition (IV) and the protective film-forming film contain an energy-ray-curable component (a) and a thermosetting component (h), heating the protective film-forming film improves its adhesion to the adherend, and also improves the strength of the cured product of the protective film-forming film (e.g., protective film).

[0121] Examples of thermosetting components (h) include epoxy thermosetting resins, polyimide resins, and unsaturated polyester resins, with epoxy thermosetting resins being preferred.

[0122] The epoxy-based thermosetting resin comprises an epoxy resin (h1) and a thermosetting agent (h2). The epoxy thermosetting resin contained in composition (IV) and the protective film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0123] • Epoxy resin (h1) Examples of epoxy resins (h1) include well-known ones, such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenylene skeleton type epoxy resins, and other bifunctional or more epoxy compounds.

[0124] As the epoxy resin (h1), an epoxy resin having unsaturated hydrocarbon groups may be used. Epoxy resins having unsaturated hydrocarbon groups have higher compatibility with acrylic resins than epoxy resins without unsaturated hydrocarbon groups. Therefore, using an epoxy resin having unsaturated hydrocarbon groups improves the reliability of the protective film-coated chip obtained using the protective film-forming composite sheet.

[0125] Examples of epoxy resins having unsaturated hydrocarbon groups include compounds obtained by converting some of the epoxy groups of a polyfunctional epoxy resin into groups having unsaturated hydrocarbon groups. Such compounds can be obtained, for example, by adding (meth)acrylic acid or a derivative thereof to the epoxy group. Furthermore, epoxy resins having unsaturated hydrocarbon groups include, for example, compounds in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring or the like that constituting the epoxy resin. The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples include the ethenyl group (vinyl group), the 2-propenyl group (allyl group), the (meth)acryloyl group, and the (meth)acrylamide group, with the acryloyl group being preferred.

[0126] The number-average molecular weight of the epoxy resin (h1) is not particularly limited, but from the viewpoint of the curability of the protective film-forming film, as well as 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. The epoxy equivalent of the epoxy resin (h1) is preferably 100 to 1000 g / eq, and more preferably 150 to 950 g / eq.

[0127] The epoxy resin (h1) contained in composition (IV) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0128] • Thermosetting agent (H2) The thermosetting agent (h2) functions as a curing agent for the epoxy resin (h1). Examples of the thermosetting agent (H2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups in which an acid group has been converted to an anhydride. It is preferable that the functional group is a phenolic hydroxyl group, an amino group, or a group in which an acid group has been converted to an anhydride, and more preferably a phenolic hydroxyl group or an amino group.

[0129] Examples of thermosetting agents (H2) that include phenolic curing agents having phenolic hydroxyl groups include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Examples of amine-based curing agents containing an amino group among the thermosetting agents (H2) include dicyandiamide.

[0130] The thermosetting agent (H2) may have an unsaturated hydrocarbon group. Examples of thermosetting agents (H2) having unsaturated hydrocarbon groups include compounds having a structure in which some of the hydroxyl groups of a phenolic resin are replaced by groups having unsaturated hydrocarbon groups, and compounds having a structure in which groups having unsaturated hydrocarbon groups are directly bonded to the aromatic ring of a phenolic resin. Examples of the unsaturated hydrocarbon group in the thermosetting agent (H2) include those similar to the unsaturated hydrocarbon group in the epoxy resin having the unsaturated hydrocarbon group described above.

[0131] When using a phenolic curing agent as the thermosetting agent (h2), it is preferable that the thermosetting agent (h2) has a high softening point or glass transition temperature, as this improves the peelability of the protective film from the support sheet.

[0132] Among the thermosetting agents (H2), the number average molecular weight of the resin components, such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins, is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000. The molecular weight of the non-resin component of the thermosetting agent (H2), such as biphenol or dicyandiamide, is not particularly limited, but is preferably 60 to 500.

[0133] The thermosetting agent (h2) contained in composition (IV) and the protective film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0134] When a thermosetting component (h) is used, the content of the thermosetting agent (h2) in composition (IV) and the protective film is preferably 0.1 to 100 parts by mass per 100 parts by mass of epoxy resin (h1). When the content of the thermosetting agent (h2) is above the lower limit, the curing of the protective film proceeds more easily. When the content of the thermosetting agent (h2) is below the upper limit, the moisture absorption rate of the protective film is reduced, and the reliability of the package obtained using the protective film-coated chip is further improved.

[0135] When a thermosetting component (h) is used, the content of the thermosetting component (h) in composition (IV) and the protective film-forming film (for example, the total content of epoxy resin (h1) and thermosetting agent (h2)) is preferably 5 to 120 parts by mass per 100 parts by mass of acrylic resin (b). Having the content of the thermosetting component (h) within this range suppresses, for example, the adhesion between the cured product of the protective film-forming film and the support sheet, thereby improving the peelability of the support sheet.

[0136] (General-purpose additive (z)) The general-purpose additive (z) may be any known additive and can be arbitrarily selected depending on the purpose; it is not particularly limited. Preferred general-purpose additives (z) include, for example, plasticizers, antistatic agents, antioxidants, gettering agents, and ultraviolet absorbers.

[0137] The general-purpose additive (z) contained in composition (IV) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0138] When using a general-purpose additive (z), the content of the general-purpose additive (z) in composition (IV) and the protective film-forming film is not particularly limited and may be appropriately selected depending on the purpose. For example, if the general-purpose additive (z) is an ultraviolet absorber, the ratio of the content of the general-purpose additive (z) (ultraviolet absorber) to the total content of all components other than the solvent in composition (IV) (i.e., the ratio of the content of the general-purpose additive (z) (ultraviolet absorber) to the total mass of the protective film-forming film in the protective film-forming film) is preferably 0.1 to 5% by mass, more preferably 0.3 to 3% by mass, and preferably 0.5 to 1.5% by mass. If the ratio is above the lower limit, the effect of using the general-purpose additive (z) will be more pronounced. If the ratio is below the upper limit, the excessive use of the general-purpose additive (z) will be suppressed.

[0139] (Other polymers (b0) that do not have energy-ray curable groups) Other polymers (b0) that do not have energy-ray curable groups impart film-forming properties to protective film-forming films. The polymer (b0) is not particularly limited as long as it does not fall under the category of acrylic resin (b). The polymer (b0) may be crosslinked with a crosslinking agent in at least a portion of its composition, or it may not be crosslinked.

[0140] Examples of the polymer (b0) include acrylic resins having a weight-average molecular weight greater than 1,100,000, acrylic resins having a dispersion degree of 3.0 or less (in this specification, these acrylic resins may be referred to as "other acrylic resins"); and polymers other than acrylic resins that do not have energy-ray curable groups.

[0141] Other acrylic resins mentioned above include those similar to acrylic resin (b), except that they have a weight-average molecular weight greater than 1,100,000 or a degree of dispersion of 3.0 or less.

[0142] Examples of polymers other than acrylic resins that do not have energy-ray curable groups include urethane resins, phenoxy resins, silicone resins, and saturated polyester resins.

[0143] The weight-average molecular weight (Mw) of polymers other than acrylic resins that do not have energy-ray curable groups is preferably 10,000 to 2,000,000, and more preferably 1,000,000 to 1,500,000, from the viewpoint of improving the film-forming properties of composition (IV).

[0144] The polymer (b0) contained in composition (IV) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0145] In composition (IV) and the protective film-forming film, the content of polymer (b0) is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, even more preferably 1 part by mass or less, and 0 parts by mass, based on 100 parts by mass of acrylic resin (b). In other words, it is particularly preferable that composition (IV) and the protective film-forming film do not contain polymer (b0). By keeping the content of polymer (b0) below the upper limit, the effect of suppressing the peeling of the protective film from the wafer or chip is further enhanced.

[0146] [solvent] Composition (IV) preferably further contains a solvent. Composition (IV) containing a solvent has good handling properties. The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The solvent contained in composition (IV) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0147] A more preferred solvent for composition (IV) is, for example, methyl ethyl ketone, which allows for more uniform mixing of the components in composition (IV).

[0148] The solvent content of composition (IV) is not particularly limited and may be appropriately selected depending on the type of components other than the solvent.

[0149] <<Method for producing a protective film-forming composition>> Composition (IV) and other energy ray-curable protective film-forming compositions are obtained by blending the respective components. There are no particular restrictions on the order in which each component is added during formulation, and two or more components may be added simultaneously. The method of mixing each component during formulation is not particularly limited; it can be appropriately selected from known methods such as mixing by rotating a stirring bar or impeller, mixing using a mixer, or mixing by applying ultrasonic waves. The temperature and time during the addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and can be adjusted as appropriate, but a temperature of 15 to 30°C is preferred.

[0150] Figure 1 is a schematic cross-sectional view showing an example of a protective film-forming film according to this embodiment. Note that, for convenience in order to make the features of the present invention easier to understand, the figures used in the following description may show enlarged versions of key parts, and the dimensional ratios of each component may not be the same as in reality.

[0151] The protective film-forming film 13 shown herein has a first release film 151 on one side (sometimes referred to as the "first side" in this specification) 13a and a second release film 152 on the other side (sometimes referred to as the "second side" in this specification) 13b opposite to the first side 13a. Such protective film-forming film 13 is suitable for storage, for example, in a roll form.

[0152] The protective film-forming film 13 has the characteristics described above. The protective film-forming film 13 can be formed using the protective film-forming composition described above.

[0153] The first release film 151 and the second release film 152 may both be known. The first release film 151 and the second release film 152 may be the same as each other, or they may be different from each other, for example, in that they require different peeling forces when peeled from the protective film forming film 13.

[0154] In the protective film-forming film 13 shown in Figure 1, one of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes the surface to be attached to the back surface of the wafer (not shown). Then, the remaining other of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes the surface to which the support sheet or dicing sheet described later will be attached.

[0155] Figure 1 shows an example in which the release film is provided on both sides (first surface 13a and second surface 13b) of the protective film forming film 13. However, the release film may be provided on only one side of the protective film forming film 13, that is, only the first surface 13a or only the second surface 13b.

[0156] The protective film-forming film of this embodiment can be attached to the back surface of a wafer without using a support sheet, which will be described later. In this case, a release film may be provided on the side of the protective film-forming film opposite to the side attached to the wafer, and this release film can be removed at an appropriate time.

[0157] On the other hand, the protective film-forming film of this embodiment can be used in combination with a support sheet, as described later, to form a composite sheet for forming a protective film that can perform both protective film formation and dicing simultaneously. Such a composite sheet for forming a protective film will be described below.

[0158] ◇ Composite sheet for forming protective film A composite sheet for forming a protective film according to one embodiment of the present invention comprises a support sheet and a protective film forming film provided on one surface of the support sheet, wherein the protective film forming film is the protective film forming film according to the above-described embodiment of the present invention. The protective film-forming composite sheet of this embodiment includes the protective film-forming film, and when the protective film-forming film is cured by energy rays, the rate of change in the indentation depth of the protective film-forming film is set to a suitable range, thereby allowing the protective film-forming film to be cured appropriately and preventing peeling of the protective film.

[0159] In this specification, as long as the laminated structure of the support sheet and the cured protective film is maintained even after the protective film has hardened, this laminated structure will be referred to as a "composite sheet for forming a protective film."

[0160] The following describes in detail each layer that constitutes the composite sheet for forming the protective film.

[0161] ◎Support sheet The support sheet may consist of one layer (single layer) or of two or more layers. If the support sheet consists of multiple layers, the constituent materials and thicknesses of these layers may be the same or different, and the combination of these layers is not particularly limited as long as it does not impair the effects of the present invention.

[0162] The support sheet is preferably transparent, but may be colored depending on the purpose. In this embodiment, where the protective film-forming film is energy ray curable, the support sheet is preferably one that transmits energy rays.

[0163] Examples of support sheets include those comprising a base material and an adhesive layer provided on one surface of the base material; or those consisting only of the base material. When the support sheet includes an adhesive layer, the adhesive layer is positioned between the base material and the protective film in the case of a composite sheet for forming a protective film.

[0164] When a support sheet comprising a base material and an adhesive layer is used, the adhesion and peelability between the support sheet and the protective film-forming film can be easily adjusted in the composite sheet for forming the protective film. When a support sheet consisting only of the base material is used, a composite sheet for forming a protective film can be manufactured at a low cost.

[0165] Examples of the composite sheet for forming the protective film in this embodiment will be described below with reference to the drawings, according to each type of support sheet.

[0166] Figure 2 is a schematic cross-sectional view showing an example of a composite sheet for forming a protective film according to this embodiment. In Figures 2 and beyond, components identical to those shown in previously explained figures are denoted by the same reference numerals, and their detailed explanations are omitted.

[0167] The protective film-forming composite sheet 101 shown herein comprises a support sheet 10 and a protective film-forming film 13 provided on one surface (sometimes referred to as the "first surface" in this specification) 10a of the support sheet 10. The support sheet 10 comprises a base material 11 and an adhesive layer 12 provided on one surface (first surface) 11a of the base material 11. In the protective film-forming composite sheet 101, the adhesive layer 12 is positioned between the base material 11 and the protective film-forming film 13. In other words, the protective film-forming composite sheet 101 is constructed by laminating a base material 11, an adhesive layer 12, and a protective film-forming film 13 in this order in the thickness direction. The first surface 10a of the support sheet 10 is the same as the surface 12a of the adhesive layer 12 that is opposite to the substrate 11 side (which may be referred to as the "first surface" in this specification).

[0168] The protective film-forming composite sheet 101 further includes a jig adhesive layer 16 and a release film 15 on the protective film-forming film 13. In the protective film-forming composite sheet 101, a protective film-forming film 13 is laminated over the entire or nearly entire surface of the first surface 12a of the adhesive layer 12, and a jig adhesive layer 16 is laminated on a portion of the surface 13a of the protective film-forming film 13 opposite to the adhesive layer 12 (sometimes referred to as the "first surface" in this specification), i.e., in the area 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 jig adhesive layer 16 is not laminated, and on the surface 16a of the jig adhesive layer 16 opposite to the protective film-forming film 13 (sometimes referred to as the "first surface" in this specification). A support sheet 10 is provided on the surface 13b of the protective film-forming film 13 opposite to the first surface 13a (sometimes referred to as the "second surface" in this specification).

[0169] In the case of the protective film-forming composite sheet 101, as well as in other cases of the protective film-forming composite sheet of this embodiment, the release film (for example, the release film 15 shown in Figure 1) can be of any configuration, and the protective film-forming composite sheet of this embodiment may or may not include a release film.

[0170] The adhesive layer 16 for the jig is used to fix the composite sheet 101 for forming a protective film to a jig such as a ring frame. The adhesive layer 16 for the jig may, for example, have a single-layer structure containing adhesive components, or it may have a multi-layer structure comprising a core sheet and layers containing adhesive components provided on both sides of the sheet.

[0171] The protective film-forming composite sheet 101 is used after the release film 15 has been removed, with the back surface of a wafer attached to the first surface 13a of the protective film-forming film 13, and further, the first surface 16a of the jig adhesive layer 16 is attached to a jig such as a ring frame.

[0172] Figure 3 is a schematic cross-sectional view showing another example of the protective film-forming composite sheet of this embodiment. The protective film-forming composite sheet 102 shown here is the same as the protective film-forming composite sheet 101 shown in Figure 2, except that the shape and size of the protective film-forming film are different, and the jig adhesive layer is laminated on the first surface of the adhesive layer instead of the first surface of the protective film-forming film.

[0173] More specifically, in the protective film-forming composite sheet 102, the protective film-forming film 23 is laminated on a portion of the first surface 12a of the adhesive layer 12, that is, on the central region in the width direction (left-right direction in Figure 3) of the adhesive layer 12. Furthermore, in the area of ​​the first surface 12a of the adhesive layer 12 where the protective film-forming film 23 is not laminated, a jig adhesive layer 16 is laminated so as to surround the protective film-forming film 23 from the outside in its width direction without contact. Then, a release film 15 is laminated 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 on the first surface 16a of the jig adhesive layer 16. A support sheet 10 is provided on the side of the protective film-forming film 23 opposite to the first surface 23a (sometimes referred to as the "second surface" in this specification) 23b.

[0174] Figure 4 is a schematic cross-sectional view showing yet another example of the composite sheet for forming a protective film according to this embodiment. The protective film-forming composite sheet 103 shown here is the same as the protective film-forming composite sheet 102 shown in Figure 3, except that it does not have a jig adhesive layer 16.

[0175] Figure 5 is a schematic cross-sectional view showing yet another example of the composite sheet for forming a protective film according to this embodiment. The protective film-forming composite sheet 104 shown here is the same as the protective film-forming composite sheet 101 shown in Figure 2, except that it is configured with a support sheet 20 instead of a support sheet 10.

[0176] The support sheet 20 consists only of the base material 11. In other words, the protective film-forming composite sheet 104 is constructed by laminating a base material 11 and a protective film-forming film 13 in the thickness direction. The side of the support sheet 20 facing the protective film-forming film 13 (first side) 20a is the same as the first side 11a of the base material 11. The substrate 11 is adhesive at least on its first surface 11a.

[0177] The composite sheet for forming the protective film in this embodiment is not limited to those shown in Figures 2 to 5. Within the limits that do not impair the effects of the present invention, some components of those shown in Figures 2 to 5 may be modified or deleted, or other components may be added to those described herein.

[0178] Next, we will describe each layer that makes up the support sheet in more detail.

[0179] ○Base material The substrate is in the form of a sheet or film, and its constituent materials include, for example, various resins. The aforementioned resins include, for example, polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer (polymers obtained using ethylene as a monomer); and vinyl chloride-based resins such as polyvinyl chloride and vinyl chloride copolymer (obtained using vinyl chloride as a monomer). Examples of materials include: modified resins; polystyrene; polycycloolefins; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and all aromatic polyesters having aromatic cyclic groups as all constituent units; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; polyether ketones, etc. Furthermore, the resin may also include, for example, a polymer alloy such as a mixture of the polyester and other resins. In the polymer alloy of polyester and other resins, it is preferable that the amount of the resin other than polyester is relatively small. Furthermore, examples of the resin include crosslinked resins obtained by crosslinking one or more of the resins exemplified so far; and modified resins such as ionomers using one or more of the resins exemplified so far.

[0180] The resin constituting the base material may consist of only one type, or two or more types. If there are two or more types, their combination and ratio can be arbitrarily selected.

[0181] The base material may consist of one layer (single layer) or of two or more layers. If it consists of multiple layers, these layers may be identical or different, and there are no particular limitations on the combination of these layers.

[0182] The thickness of the substrate is preferably 50 to 300 μm, and more preferably 60 to 100 μm. Having the substrate thickness within this range improves the flexibility of the composite sheet for protective film formation and its suitability for adhesion to the wafer. Here, "substrate thickness" refers to the total thickness of the substrate. For example, the thickness of a substrate consisting of multiple layers refers to the total thickness of all the layers that make up the substrate.

[0183] In addition to the main constituent materials such as the aforementioned resin, the base material may also contain various known additives such as fillers, colorants, antioxidants, organic lubricants, catalysts, and plasticizers.

[0184] The substrate is preferably transparent, but may be colored or have other layers deposited on it depending on the purpose. In this embodiment, where the protective film-forming film is energy ray curable, the substrate is preferably one that transmits energy rays.

[0185] The substrate may have its surface treated with sandblasting, solvent treatment, or other surface treatments to adjust its adhesion to the layer provided thereon (for example, an adhesive layer, a protective film-forming film, or the aforementioned other layer); oxidation treatments such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, or hot air treatment; lipophilic treatment; hydrophilic treatment, etc. The substrate may also have its surface treated with a primer.

[0186] The base material may contain components within a specific range (e.g., resin, etc.) to have adhesive properties on at least one surface.

[0187] The substrate can be manufactured by known methods. For example, a substrate containing a resin can be manufactured by molding a resin composition containing the resin.

[0188] ○ Adhesive layer The adhesive layer is in the form of a sheet or film and contains an adhesive. Examples of the adhesive include adhesive resins such as acrylic resin, urethane resin, rubber resin, silicone resin, epoxy resin, polyvinyl ether, polycarbonate, and ester resin.

[0189] In this specification, "adhesive resin" includes both resins that are tacky and resins that are adhesive. For example, the adhesive resin includes not only resins that are tacky in themselves, but also resins that exhibit tackiness when used in combination with other components such as additives, and resins that exhibit adhesiveness in the presence of triggers such as heat or water.

[0190] The adhesive layer may consist of one layer (single layer) or of two or more layers. If it consists of multiple layers, these layers may be identical or different, and there are no particular limitations on the combination of these layers.

[0191] The thickness of the adhesive layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 1 to 60 μm, and especially preferably 1 to 30 μm. Here, "thickness of the adhesive layer" refers to the total 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.

[0192] The adhesive layer is preferably transparent, but may be colored depending on the purpose. In this embodiment, where the protective film-forming film has energy ray curability, it is preferable that the adhesive layer is one that transmits energy rays.

[0193] The adhesive layer may be either energy-ray curable or non-energy-ray curable. The physical properties of the energy-ray curable adhesive layer can be adjusted before and after curing. For example, curing the energy-ray curable adhesive layer before picking up the protective film-coated chip (described later) makes it easier to pick up the chip. If the adhesive layer is non-energy-ray curable, it exhibits high photostability and excellent storage stability.

[0194] An adhesive layer can be formed using an adhesive composition containing an adhesive. For example, an adhesive layer can be formed on the desired area by applying the adhesive composition to the surface on which the adhesive layer is to be formed and drying it as needed. The ratio of components that do not vaporize at room temperature in the adhesive composition is usually the same as the ratio of those components in the adhesive layer.

[0195] The adhesive composition can be coated and dried, for example, in the same manner as the coating and drying of the protective film-forming composition described above.

[0196] When providing an adhesive layer on a substrate, for example, the adhesive composition can be applied to the substrate and dried as necessary. Alternatively, for example, the adhesive composition can be applied to a release film and dried as necessary to form an adhesive layer on the release film, and the exposed surface of this adhesive layer can be bonded to one surface of the substrate to laminate the adhesive layer onto the substrate. In this case, the release film can be removed at either the manufacturing or use stage of the protective film-forming composite sheet.

[0197] When the adhesive layer is energy ray curable, examples of energy ray curable adhesive compositions include: adhesive composition (I-1) containing a non-energy ray curable adhesive resin (I-1a) (hereinafter sometimes abbreviated as "adhesive resin (I-1a)") and an energy ray curable compound; adhesive composition (I-2) containing an energy ray curable adhesive resin (I-2a) (hereinafter sometimes abbreviated as "adhesive resin (I-2a)") in which an unsaturated group is introduced into the side chain of the non-energy ray curable adhesive resin (I-1a); and adhesive composition (I-3) containing the aforementioned adhesive resin (I-2a) and an energy ray curable compound.

[0198] When the adhesive layer is non-energy ray curable, examples of non-energy ray curable adhesive compositions include adhesive compositions (I-4) containing the non-energy ray curable adhesive resin (I-1a).

[0199] [Non-energy ray curable adhesive resin (I-1a)] The adhesive resin (I-1a) is preferably an acrylic resin.

[0200] Examples of the acrylic resin include acrylic polymers having at least one structural unit derived from an alkyl (meth)acrylate ester. Examples of the alkyl (meth)acrylate ester include those in which the alkyl group constituting the alkyl ester has 1 to 20 carbon atoms, and the alkyl group is preferably linear or branched.

[0201] The acrylic polymer preferably has, in addition to structural units derived from alkyl (meth)acrylate esters, structural units derived from functional group-containing monomers. Examples of the functional group-containing monomers include those in which the functional group reacts with a crosslinking agent (described later) to serve as a starting point for crosslinking, or those in which the functional group reacts with functional groups such as isocyanate groups and glycidyl groups in an unsaturated group-containing compound (described later) to enable the introduction of unsaturated groups into the side chains of acrylic polymers.

[0202] Examples of the functional group-containing monomers include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, and the like.

[0203] The acrylic polymer may have structural units derived from other monomers, in addition to structural units derived from alkyl (meth)acrylate esters and structural units derived from functional group-containing monomers. The other monomers mentioned above are not particularly limited as long as they can be copolymerized with alkyl (meth)acrylate esters, etc. Examples of other monomers include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

[0204] In the aforementioned adhesive compositions (I-1), (I-2), (I-3), and (I-4) (hereinafter, these adhesive compositions will be collectively referred to as "adhesive compositions (I-1) to (I-4)"), the constituent units of the acrylic resin, such as the acrylic polymer, may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0205] In the acrylic polymer, the ratio of the amount of constituent units derived from functional group-containing monomers to the total amount of constituent units is preferably 1 to 35% by mass.

[0206] The adhesive resin (I-1a) contained in adhesive composition (I-1) or adhesive composition (I-4) may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be arbitrarily selected.

[0207] In an adhesive layer formed from adhesive composition (I-1) or adhesive composition (I-4), the ratio of the content of adhesive resin (I-1a) to the total mass of the adhesive layer is preferably 5 to 99% by mass, and may be, for example, 25 to 95% by mass, 45 to 95% by mass, or 65 to 95% by mass.

[0208] [Energy ray curable adhesive resin (I-2a)] The adhesive resin (I-2a) can be obtained, for example, by reacting a functional group in the adhesive resin (I-1a) with an unsaturated group-containing compound having an energy-ray polymerizable unsaturated group.

[0209] The aforementioned unsaturated group-containing compound is a compound that, in addition to the energy-ray polymerizable unsaturated group, has a group that can bond to the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a). Examples of the energy-ray polymerizable unsaturated group include a (meth)acryloyl group, a vinyl group (ethenyl group), an allyl group (2-propenyl group), and the (meth)acryloyl group, which is preferred. Examples of groups that can bond to functional groups in the adhesive resin (I-1a) include isocyanate groups and glycidyl groups that can bond to hydroxyl groups or amino groups, and hydroxyl groups and amino groups that can bond to carboxyl groups or epoxy groups.

[0210] Examples of the unsaturated group-containing compounds include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

[0211] The adhesive resin (I-2a) contained in the adhesive composition (I-2) or (I-3) may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be arbitrarily selected.

[0212] In an adhesive layer formed from adhesive composition (I-2) or (I-3), the ratio of the content of adhesive resin (I-2a) to the total mass of the adhesive layer is preferably 5 to 99% by mass.

[0213] [Energy ray curable compound] The energy-ray curable compound contained in the adhesive composition (I-1) or (I-3) includes monomers or oligomers having energy-ray polymerizable unsaturated groups that can be cured by irradiation with energy rays.

[0214] Examples of monomers among energy-ray curable compounds include polyvalent (meth)acrylates such as trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol (meth)acrylate; urethane (meth)acrylate; polyester (meth)acrylate; polyether (meth)acrylate; and epoxy (meth)acrylate. Examples of energy-ray curable compounds include oligomers, which are polymers of the monomers exemplified above.

[0215] The energy ray curable compound contained in the adhesive composition (I-1) or (I-3) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0216] In an adhesive layer formed from adhesive composition (I-1) or (I-3), the ratio of the content of the energy ray curable compound to the total mass of the adhesive layer is preferably 1 to 95% by mass.

[0217] [Crosslinking agent] When the acrylic polymer used as the adhesive resin (I-1a) has structural units derived from functional group-containing monomers in addition to structural units derived from alkyl (meth)acrylate, it is preferable that the adhesive composition (I-1) or (I-4) further contains a crosslinking agent. Furthermore, when using the acrylic polymer having functional group-containing monomer-derived structural units, similar to those in the tacky resin (I-1a), as the tacky resin (I-2a), the adhesive composition (I-2) or (I-3) may further contain a crosslinking agent.

[0218] The crosslinking agent reacts, for example, with the functional group to crosslink adhesive resins (I-1a) with each other or adhesive resins (I-2a) with each other. Examples of crosslinking agents include isocyanate-based crosslinking agents (crosslinking agents having an isocyanate group) such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy-based crosslinking agents (crosslinking agents having a glycidyl group) such as ethylene glycol glycidyl ether; aziridine-based crosslinking agents (crosslinking agents having an aziridinyl group) such as hexa[1-(2-methyl)-aziridinyl]triphosphate triazine; metal chelate-based crosslinking agents (crosslinking agents having a metal chelate structure) such as aluminum chelate; and isocyanurate-based crosslinking agents (crosslinking agents having an isocyanuric acid skeleton).

[0219] The crosslinking agent contained in adhesive compositions (I-1) to (I-4) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0220] In the adhesive composition (I-1) or (I-4), the crosslinking agent content is preferably 0.01 to 50 parts by mass per 100 parts by mass of the adhesive resin (I-1a), and may be, for example, 1 to 40 parts by mass, 5 to 35 parts by mass, or 10 to 30 parts by mass. In the adhesive composition (I-2) or (I-3), the crosslinking agent content is preferably 0.01 to 50 parts by mass per 100 parts by mass of the adhesive resin (I-2a).

[0221] [Photopolymerization initiator] 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. Adhesive compositions (I-1) to (I-3) containing a photopolymerization initiator will undergo a sufficient curing reaction even when irradiated with relatively low-energy rays such as ultraviolet light.

[0222] Examples of the photopolymerization initiator include those similar to the photopolymerization initiator (c) described above.

[0223] The photopolymerization initiator contained in the adhesive compositions (I-1) to (I-3) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0224] In adhesive composition (I-1), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the energy ray curable compound. In adhesive composition (I-2), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the adhesive resin (I-2a). In the adhesive composition (I-3), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the total content of the adhesive resin (I-2a) and the energy ray curable compound.

[0225] [Other additives] The adhesive compositions (I-1) to (I-4) may contain other additives that do not fall under any of the above-mentioned components, as long as they do not impair the effects of the present invention. Examples of the other additives include known additives such as antistatic agents, antioxidants, softeners (plasticizers), fillers, rust inhibitors, colorants (pigments, dyes), sensitizers, tackifiers, reaction retarders, crosslinking accelerators (catalysts), and the like. The reaction retarder is a component that suppresses the progress of an unintended crosslinking reaction in the adhesive compositions (I-1) to (I-4) during storage, by the action of a catalyst mixed in the adhesive compositions (I-1) to (I-4). Examples of the reaction retarder include those that form a chelate complex by a chelate with respect to the catalyst, and more specifically, those having two or more carbonyl groups (-C(=O)-) in one molecule.

[0226] The other additives contained in the adhesive compositions (I-1) to (I-4) may be only one kind or two or more kinds. In the case of two or more kinds, their combinations and ratios can be arbitrarily selected.

[0227] The content of the other additives in the adhesive compositions (I-1) to (I-4) is not particularly limited and may be appropriately selected according to the type thereof.

[0228] [Solvent] The adhesive compositions (I-1) to (I-4) may contain a solvent. By containing a solvent, the adhesive compositions (I-1) to (I-4) improve the coating suitability on the surface to be coated.

[0229] The solvent is preferably an organic solvent. Examples of the organic solvent include ketones such as methyl ethyl ketone and acetone; esters (carboxylic acid esters) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; alcohols such as 1-propanol and 2-propanol, and the like.

[0230] The solvent contained in adhesive compositions (I-1) to (I-4) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0231] The solvent content of adhesive compositions (I-1) to (I-4) is not particularly limited and may be adjusted as appropriate.

[0232] ○ Method for manufacturing adhesive compositions Adhesive compositions such as (I-1) to (I-4) are obtained by blending the adhesive with other components, as needed, to constitute the adhesive composition. The adhesive composition can be manufactured in the same manner as the protective film-forming composition described earlier, except that the types of components used are different.

[0233] ◇Method for manufacturing a composite sheet for forming a protective film The composite sheet for forming the protective film can be manufactured by laminating the above-mentioned layers in corresponding positional relationships and, if necessary, adjusting the shape of some or all of the layers. The method for forming each layer is as described above.

[0234] For example, when manufacturing a support sheet and laminating an adhesive layer onto a substrate, the above-mentioned adhesive composition can be applied to the substrate and dried as necessary. Alternatively, an adhesive layer can be laminated onto a substrate by applying an adhesive composition to a release film, drying it as needed to form an adhesive layer on the release film, and then bonding the exposed surface of this adhesive layer to one surface of the substrate. In this case, it is preferable to apply the adhesive composition to the release surface of the release film. Up to this point, we have used the example of laminating an adhesive layer on a substrate, but the method described above can also be applied to cases where other layers besides the adhesive layer are laminated on the substrate.

[0235] On the other hand, for example, when laminating a protective film-forming film on top of an adhesive layer already laminated on a substrate, it is possible to directly form the protective film-forming film by coating the adhesive layer with a protective film-forming composition. Layers other than the protective film-forming film can also be laminated on the adhesive layer in a similar manner using a composition for forming that layer. Thus, when forming a new layer (hereinafter abbreviated as "second layer") on top of any layer already laminated on a substrate (hereinafter abbreviated as "first layer") to form a continuous two-layer laminated structure (in other words, a laminated structure of the first and second layers), a method can be applied in which the composition for forming the second layer is coated onto the first layer and dried as necessary. However, it is preferable to pre-form the second layer on the release film using a composition for forming it, and then bond the exposed surface of the pre-formed second layer opposite to the side in contact with the release film to the exposed surface of the first layer to form a continuous two-layer laminated structure. In this case, it is preferable to coat the release treatment surface of the release film with the composition. The release film may be removed as needed after the laminated structure is formed. Here, we have given an example of laminating a protective film on an adhesive layer, but the target laminated structure can be arbitrarily selected, for example, when laminating a layer (film) other than a protective film on an adhesive layer.

[0236] Thus, since all layers other than the substrate that make up the composite sheet for forming a protective film can be pre-formed on a release film and laminated by bonding them to the surface of the target layer, the composite sheet for forming a protective film can be manufactured by appropriately selecting the layers to which such a process is employed as needed.

[0237] In addition, the composite sheet for forming a protective film is usually stored with a release film attached to the surface of the outermost layer (e.g., the protective film-forming film) opposite to the support sheet. Therefore, a composition for forming the outermost layer, such as a protective film-forming composition, is applied to this release film (preferably its release-treated surface), and dried as necessary to form the outermost layer on the release film. The remaining layers are then laminated on the exposed surface of this layer opposite to the side in contact with the release film using one of the methods described above, and the release film is not removed, resulting in a composite sheet for forming a protective film with a release film.

[0238] The composite sheet for forming the protective film may be in the form of a single leaf, but is preferably in the form of a roll.

[0239] ◇ Kit A kit according to one embodiment of the present invention comprises a first laminate in which a first release film and a protective film forming film are laminated in that order, and a support sheet used to support a workpiece to which the protective film forming film is to be attached and the protective film forming film, wherein the protective film forming film is the protective film forming film according to the above-described embodiment of the present invention. An example of Kit 1 of this embodiment will be described below with reference to the drawings.

[0240] Figure 6 is a schematic cross-sectional view showing an example of Kit 1 of this embodiment. The kit 1 of this embodiment comprises a first laminate 5 in which a first release film 151, a protective film forming film 13, and a second release film 152 are laminated in this order, and a support sheet 10 used to support the workpiece to which the protective film forming film 13 is to be attached and the protective film forming film 13, wherein the support sheet 10 is the support sheet according to the embodiment of the present invention described above.

[0241] The protective film forming film 13 shown here has a first release film 151 on one of its surfaces (which may be referred to as the "first surface" in this specification) 13a, and a second release film 152 on the other surface (which may be referred to as the "second surface" in this specification) 13b opposite to the first surface 13a.

[0242] By using the kit 1 including the support sheet 10 and the protective film forming film, a chip with a protective film can be manufactured by the method for manufacturing a chip with a protective film described later, which includes a chip and a protective film provided on the back surface of the chip.

[0243] Such a protective film forming film 13 is suitable for storage in a roll shape, for example. That is, it is preferable that the first laminate is in a roll shape.

[0244] The protective film forming film 13 can be formed using the above-described composition for forming a protective film.

[0245] Both the first release film 151 and the second release film 152 may be known ones. The first release film 151 and the second release film 152 may be the same as each other, or may be different from each other, for example, having different release forces required when peeling from the protective film forming film 13.

[0246] In the protective film forming film 13 shown in FIG. 6, either one of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes the sticking surface to the back surface of the workpiece (not shown). Then, the remaining other one of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes the sticking surface of the support sheet.

[0247] Figure 6 shows an example in which the release film is provided on both sides (first surface 13a and second surface 13b) of the protective film forming film 13. However, the release film may be provided on only one side of the protective film forming film 13, that is, only the first surface 13a or only the second surface 13b.

[0248] Kit 1 of this embodiment allows for the application of the protective film to the workpiece and the subsequent application of the support sheet to the workpiece in an in-line process by using the protective film forming film 13 and the support sheet 10 together. Here, "in-line process" refers to a process performed in a device in which multiple devices (multiple units) that perform one or more processes are connected, or within the same device, and includes multiple processes and the transport that connects those processes, with workpieces being transported one by one between each process.

[0249] ◇Manufacturing method for chips with protective coating (Method of using protective coating-forming film, protective coating-forming composite sheet, and kit) The protective film forming film, the composite sheet for forming the protective film, and the kit can be used in the manufacture of the chip with the protective film. In other words, the method for manufacturing a chip with a protective film according to this embodiment is a method for manufacturing a chip with a protective film comprising a chip and a protective film provided on the back surface of the chip, comprising the steps of: 1) manufacturing a first laminated film in which the protective film forming film and the wafer are laminated in the thickness direction by attaching the protective film forming film according to the above embodiment to the back surface of a wafer, or 2) manufacturing a first laminated composite sheet in which the support sheet, protective film forming film and wafer are laminated in this order in the thickness direction by attaching the protective film forming film from the protective film forming composite sheet according to the above embodiment to the back surface of a wafer (this may be referred to as the "attachment step" in this specification); and 3) manufacturing a second laminated film in which the protective film and the wafer are laminated in the thickness direction by energy ray curing the protective film forming film in the first laminated film or the first laminated composite sheet, or 4) the support sheet, protective film and The process includes: a step of producing a second laminated composite sheet in which EHA is laminated in this order in the thickness direction (sometimes referred to as a "curing step" in this specification); a step of producing a third laminated film in which a plurality of protective film-covered chips are fixed on the dicing sheet by dividing the wafer in the second laminated film and cutting the protective film, while a dicing sheet is provided on the protective film side of the second laminated film; or a step of producing a third laminated composite sheet in which a plurality of protective film-covered chips are fixed on the support sheet by dividing the wafer in the second laminated composite sheet and cutting the protective film (sometimes referred to as a "dividing step" in this specification); and a step of picking up the protective film-covered chips in the third laminated film by pulling them away from the dicing sheet, or by pulling the protective film-covered chips in the third laminated composite sheet away from the support sheet (sometimes referred to as a "pickup step" in this specification).

[0250] Hereinafter, with reference to the drawings, we will sequentially describe a method for manufacturing a chip with a protective film when a protective film forming film that does not constitute a protective film forming composite sheet (i.e., the protective film forming film in the kit) is attached to the back surface of the wafer (this may be referred to as "Manufacturing Method 1" in this specification), and a method for manufacturing a chip with a protective film when a protective film forming film from a protective film forming composite sheet is attached to the back surface of the wafer (this may be referred to as "Manufacturing Method 2" in this specification).

[0251] <<Manufacturing method 1>> Figure 7 is a cross-sectional view illustrating manufacturing method 1. Here, manufacturing method 1 will be explained using the protective film-forming film 13 shown in Figure 1, or more specifically, the kit shown in Figure 6, as an example. In the bonding step of manufacturing method 1, as shown in Figure 7(a), the protective film forming film 13 is attached to the back surface 9b of the wafer 9 to produce a first laminated film 601 in which the protective film forming film 13 and the wafer 9 are laminated in the thickness direction. The first surface 13a of the protective film forming film 13 is attached to the back surface 9b of the wafer 9. A second release film 152 is provided on the second surface 13b of the protective film forming film 13. Here, we show the case where the first release film 151 is removed from the protective film forming film 13 shown in Figure 1, and the first surface 13a of the protective film forming film 13 is attached to the back surface 9b of the wafer 9. However, the second release film 152 may be removed from the protective film forming film 13 shown in Figure 1, and the second surface 13b of the protective film forming film 13 may be attached to the back surface 9b of the wafer 9.

[0252] The protective film 13 can be attached to the wafer 9 by a known method. For example, the protective film 13 may be attached to the wafer 9 while being heated.

[0253] Next, in the curing step of manufacturing method 1, the protective film forming film 13 in the first laminated film 601 is cured by energy rays to form a protective film 13', thereby producing a second laminated film 602 in which the protective film 13' and the wafer 9 are laminated in the thickness direction, as shown in Figure 7(b). Reference numeral 13a' indicates the surface of the protective film 13' that was the first surface 13a of the protective film forming film 13 (sometimes referred to as the "first surface" in this specification). Reference numeral 13b' indicates the surface of the protective film 13' that was the second surface 13b of the protective film forming film 13 (sometimes referred to as the "second surface" in this specification).

[0254] In the curing process, the protective film 13' is formed by irradiating the protective film forming film 13 with energy rays from outside the protective film forming film 13 side of the first laminated film 601, through the second release film 152 (through the second release film 152). In the curing step, the second release film 152 may be removed from the protective film forming film 13 in the first laminated film 601, exposing the second surface 13b of the protective film forming film 13, and then the protective film 13' may be formed by irradiating the protective film forming film 13 with energy rays.

[0255] The irradiation conditions for the energy rays in the curing process are as described above.

[0256] The protective film 13 shown in Figure 7(a) may be laser-marked by irradiating it with a laser through the second release film 152 (allowing the laser to pass through the second release film 152), or the protective film 13' shown in Figure 7(b) may be laser-marked by irradiating it with a laser through the second release film 152 (allowing the laser to pass through the second release film 152).

[0257] Next, in the dividing step of manufacturing method 1, the second release film 152 is first removed from the protective film 13' in the second laminated film 602. Then, one side (sometimes referred to as the "first side" in this specification) 8a of the dicing sheet 8 is attached to the second side 13b' of the protective film 13' that has been newly exposed, as shown in Figure 7(c). The dicing sheet 8 shown herein comprises a base material 81 and an adhesive layer 82 provided on one surface 81a of the base material 81, with the adhesive layer 82 in the dicing sheet 8 being attached to the protective film 13'. The surface 82a of the adhesive layer 82 facing the protective film 13' (sometimes referred to as the "first surface" in this specification) is the same as the first surface 8a of the dicing sheet 8.

[0258] The dicing sheet 8 may be a known material. For example, the base material 81 may be the same as the base material in the composite sheet for forming the protective film described above, and the adhesive layer 82 may be the same as the adhesive layer in the composite sheet for forming the protective film described above. In other words, the dicing sheet 8 can be replaced with the support sheet 10.

[0259] Here, we describe the case where a dicing sheet 8 comprising a base material 81 and an adhesive layer 82 is used, but in the division step, other materials may be used as the dicing sheet, for example, a dicing sheet consisting only of a base material.

[0260] Next, in the division process, as shown in Figure 7(d), with the dicing sheet 8 provided on the protective film 13' side of the second laminated film 602, the wafer 9 in the second laminated film 602 is divided and the protective film 13' is cut. The wafer 9 is divided into individual pieces, becoming multiple chips 90.

[0261] The wafer 9 and the protective film 13' can be divided by known methods. For example, the wafer 9 and the protective film 13' can be divided continuously by various dicing methods such as blade dicing, laser dicing using laser irradiation, or water dicing by spraying water containing an abrasive. Regardless of the cutting method, the protective film 13' is cut along the outer circumference of the chip 90.

[0262] In this way, by dividing the wafer 9 and cutting the protective film 13', a plurality of protective film-covered chips 901 are obtained, each comprising a chip 90 and a protective film (sometimes simply referred to as "protective film" in this specification) 130' provided on the back surface 90b of the chip 90 after cutting. Reference numeral 130b' indicates the surface of the protective film 130' after cutting that was the second surface 13b' of the protective film 13' (sometimes referred to as "second surface" in this specification).

[0263] In the division step of manufacturing method 1, a third laminated film 603 is produced by fixing these multiple protective film-coated chips 901 on the dicing sheet 8.

[0264] Next, in the pickup step of manufacturing method 1, as shown in Figure 7(e), the protective film-covered chip 901 in the third laminated film 603 is picked up by pulling it away from the dicing sheet 8. In the pickup process, delamination occurs between the second surface 130b' of the protective film 130' in the protective film-coated chip 901 and the first surface 82a of the adhesive layer 82 in the dicing sheet 8.

[0265] This diagram shows the case where the protective film-coated tip 901 is separated in the direction of arrow P using a separation means 7 such as a vacuum collet. Note that the cross-sectional view of the separation means 7 is omitted here. The protective film-covered chip 901 can be picked up by known methods.

[0266] If the adhesive layer 82 is energy ray curable, in the pickup step, it is preferable to cure the adhesive layer 82 by irradiating it with energy rays to form a cured product (not shown), and then pull the protective film-coated chip 901 away from the dicing sheet 8. In this case, in the pickup step, delamination occurs between the protective film 130' in the protective film-coated chip 901 and the cured product of the adhesive layer 82 in the dicing sheet 8. In this case, the cured adhesive layer 82 becomes less prone to deformation compared to before curing, making it easier to pick up the protective film-covered chip 901.

[0267] The energy ray irradiation conditions for the adhesive layer 82 in the pickup step may be the same as, for example, the energy ray irradiation conditions for the protective film forming film 13 in the curing step.

[0268] In this specification, even after the energy-ray curable adhesive layer has been cured by energy rays, as long as the laminated structure of the substrate and the cured product of the energy-ray curable adhesive layer is maintained, this laminated structure will be referred to as a "dicing sheet".

[0269] On the other hand, if the adhesive layer 82 is non-energy ray curable, the protective film-covered chip 901 can be simply pulled away from the adhesive layer 82, and curing of the adhesive layer 82 is unnecessary. Therefore, the protective film-covered chip 901 can be picked up in a simplified process. Even if the adhesive layer 82 is energy ray curable, the protective film-coated chip 901 can be picked up in a simplified process by picking it up without curing the adhesive layer 82.

[0270] In the aforementioned pickup process, the pickup of such protective film-coated chips 901 is performed for all of the target protective film-coated chips 901.

[0271] In manufacturing method 1, the desired protective film-coated chip 901 is obtained by performing the pickup step.

[0272] In conventional energy-ray curable protective film-forming films, when energy rays were irradiated onto the protective film-forming film through a release film, the protective film-forming film sometimes did not cure sufficiently, making the protective film prone to peeling off. This improper curing of the protective film-forming film could potentially hinder the subsequent manufacturing of semiconductor devices. In manufacturing method 1, since a protective film-forming film according to the above-described embodiment is used, the protective film-forming film can be appropriately cured and the peeling of the protective film can be suppressed by setting the rate of change of the indentation depth of the protective film-forming film within a suitable range during energy ray curing of the protective film-forming film.

[0273] <<Manufacturing method 2>> Figure 8 is a schematic cross-sectional view illustrating manufacturing method 2. Here, manufacturing method 2 will be explained using the case where the protective film-forming composite sheet 101 shown in Figure 2 is used as an example. In the bonding step of manufacturing method 2, as shown in Figure 8(a), the protective film-forming film 13 in the protective film-forming composite sheet 101 is bonded to the back surface 9b of the wafer 9, thereby producing a first laminated composite sheet 501 in which the support sheet 10, the protective film-forming film 13, and the wafer 9 are laminated in this order in the thickness direction. In this case as well, similar to manufacturing method 1, the first surface 13a of the protective film-forming film 13 in the protective film-forming composite sheet 101 is bonded to the back surface 9b of the wafer 9.

[0274] The protective film-forming film 13 in the protective film-forming composite sheet 101 can be attached to the wafer 9 by a known method. For example, the protective film-forming film 13 may be attached to the wafer 9 while being heated.

[0275] Next, in the curing step of manufacturing method 2, the protective film forming film 13 in the first laminated composite sheet 501 is cured by energy rays to form a protective film 13', thereby producing a second laminated composite sheet 502 in which the support sheet 10, protective film 13', and wafer 9 are laminated in this order in the thickness direction, as shown in Figure 8(b).

[0276] In the curing process, a protective film 13' is formed by irradiating the protective film-forming film 13 with energy rays from outside the support sheet 10 side of the first laminated composite sheet 501, through the support sheet 10 (through the support sheet 10).

[0277] The curing step can be carried out in the same manner as the curing step in manufacturing method 1, except that the first laminated composite sheet 501 is used instead of the first laminated film 601.

[0278] The second laminated composite sheet 502 obtained in the curing step has the same structure as the laminate of the second laminated film 602 and the dicing sheet 8 in the dividing step of manufacturing method 1. If the dicing sheet 8 is the same as the support sheet 10, the second laminated composite sheet 502 is the same as the laminate.

[0279] Next, in the division step of manufacturing method 2, as shown in Figure 8(c), the wafer 9 in the second laminated composite sheet 502 is divided and the protective film 13' is cut. The wafer 9 is divided into individual pieces, which become multiple chips 90.

[0280] The aforementioned dividing step can be carried out in the same manner as the dividing step in manufacturing method 1, except that the second laminated composite sheet 502 is used instead of the laminate of the second laminated film 602 and the dicing sheet 8. In manufacturing method 2 as well, the protective film 13' is cut along the outer circumference of the chip 90, regardless of the cutting method.

[0281] In this way, by dividing the wafer 9 and cutting the protective film 13', multiple protective film-covered chips 901 are obtained, each comprising a chip 90 and the protective film 130' provided on the back surface 90b of the chip 90 after cutting. The protective film-coated chips 901 obtained in the division step in manufacturing method 2 are the same as the protective film-coated chips 901 obtained in the division step in manufacturing method 1.

[0282] The protective film 13 shown in Figure 8(a) may be laser-marked by irradiating it with a laser through the support sheet 10 (allowing the laser to pass through the support sheet 10), or the protective film 13' shown in Figure 8(b) may be laser-marked by irradiating it with a laser through the support sheet 10 (allowing the laser to pass through the support sheet 10).

[0283] In the division step of manufacturing method 2, a third laminated composite sheet 503 is produced by fixing these multiple protective film-coated chips 901 on the support sheet 10. The third laminated composite sheet 503 has the same structure as the third laminated film 603 obtained in the division step of manufacturing method 1. If the dicing sheet 8 is the same as the support sheet 10, the third laminated composite sheet 503 is the same as the third laminated film 603.

[0284] Next, in the pickup step of manufacturing method 2, as shown in Figure 8(d), the protective film-covered chip 901 in the third laminated composite sheet 503 is picked up by pulling it away from the support sheet 10. In the pickup process, delamination occurs between the second surface 130b' of the protective film 130' in the protective film-covered chip 901 and the first surface 12a of the adhesive layer 12 in the support sheet 10.

[0285] The aforementioned pickup process can be carried out in the same manner as the pickup process in manufacturing method 1, except that the third laminated composite sheet 503 is used instead of the third laminated film 603.

[0286] For example, if the adhesive layer 12 is energy ray curable, in the pickup step, it is preferable to cure the adhesive layer 12 by irradiating it with energy rays to form a cured product (not shown), and then pull the protective film-covered chip 901 away from the support sheet 10. In this case, in the pickup step, delamination occurs between the protective film 130' in the protective film-covered chip 901 and the cured product of the adhesive layer 12 in the support sheet 10. In this case, the cured adhesive layer 12 becomes less prone to deformation compared to before curing, making it easier to pick up the protective film-covered chip 901.

[0287] On the other hand, if the adhesive layer 12 is non-energy ray curable, the protective film-covered chip 901 can be simply pulled away from the adhesive layer 12, and curing of the adhesive layer 12 is unnecessary. Therefore, the protective film-covered chip 901 can be picked up in a simplified process. Even if the adhesive layer 12 is energy ray curable, the protective film-coated chip 901 can be picked up in a simplified process by picking it up without curing the adhesive layer 12.

[0288] In manufacturing method 2, the desired protective film-coated chip 901 is obtained by performing the pickup step. The protective film-coated chip 901 obtained in manufacturing method 2 is the same as the protective film-coated chip 901 obtained in manufacturing method 1.

[0289] Conventional composite sheets for forming protective films, which include an energy-ray curable protective film-forming film, had a problem in that when the protective film-forming film was irradiated with energy rays through the support sheet 10, the protective film-forming film did not cure sufficiently, making the protective film prone to peeling off. In this way, when the protective film-forming film was not properly cured, there was a risk that it would hinder the subsequent manufacturing of semiconductor devices. In manufacturing method 2, since the above-described composite sheet for forming a protective film, which includes the protective film forming film according to the above-described embodiment of the present invention, is used, the protective film forming film can be suitably cured and peeling of the protective film can be suppressed by setting the rate of change of the indentation depth of the protective film forming film to a suitable range during energy ray curing of the protective film forming film.

[0290] Up to this point, we have described manufacturing method 2 using the protective film-forming composite sheet 101 shown in Figure 2. However, in manufacturing method 2, other protective film-forming composite sheets of this embodiment may be used, such as the protective film-forming composite sheet 102, protective film-forming composite sheet 103, or protective film-forming composite sheet 104 shown in Figures 3 to 5.

[0291] ◇Manufacturing method for substrate devices (Method of using chips with protective film) After obtaining a chip with a protective film using the manufacturing method described above, the substrate device can be manufactured in the same manner as the conventional face-down substrate device manufacturing method, except that this chip with a protective film is used instead of a conventional chip with a protective film.

[0292] For example, one method of manufacturing a circuit board device involves a reflow process in which a circuit board on which a protective film-coated chip obtained using the protective film-forming film is mounted is heated using a reflow furnace equipped with a halogen heater, thereby melting the protruding electrodes on the protective film-coated chip and strengthening the electrical connection between the protruding electrodes and the connection pads on the circuit board.

[0293] The substrate device of this embodiment uses the above-described kit or the above-described composite sheet for forming the protective film, thereby enabling the protective film to be suitably cured and preventing the protective film from peeling off.

[0294] ◇ Use of protective film The use of the protective film forming film according to an embodiment of the present invention is the use of a protective film forming film for forming a protective film on a surface opposite to the circuit surface of a semiconductor wafer or a semiconductor chip (i.e., the back surface), and the protective film forming film is the protective film forming film according to an embodiment of the present invention described above. The use of the protective film forming film of the present embodiment is provided with the protective film forming film, so that when the protective film forming film is cured by energy rays, the change rate of the pushing depth of the protective film forming film is in a suitable range, and the protective film forming film can be preferably cured, and the peeling of the protective film can be suppressed.

[0295] The use of the protective film forming film of the present invention has the following aspects. <11> The use of a protective film forming film for forming a protective film on a surface opposite to the circuit surface of a semiconductor wafer or a semiconductor chip, The protective film forming film is an energy ray curable protective film forming film, The use of a protective film forming film in which the change rate of the pushing depth measured by the following method for measuring the change rate of the pushing depth of the protective film forming film is 60% or more. <Method for measuring the change rate of the pushing depth> For the protective film forming film, ultraviolet rays with a wavelength of 365 nm are irradiated under the conditions of an illuminance of 220 mW / cm 2 , a light quantity of 500 mJ / cm 2 to produce a cured protective film forming film. For the protective film forming film before and after curing, a nanoindentation tester is used to measure the indentation depth (μm) under the following conditions. Indenter: Triangular pyramid with a tip curvature radius of 0.1 μm or less Measurement mode: Load-unload test <000115​​​​​​​​Next, the difference between the indentation depth of the protective film-forming film after curing and the indentation depth of the protective film-forming film before curing is calculated using the following formula (1), and this is defined as the rate of change in the indentation depth of the protective film-forming film. The percentage change in indentation depth [%] = {(indentation depth of protective film before curing - indentation depth of protective film after curing) / indentation depth of protective film before curing} × 100 ... (1) <12> The protective film-forming film contains an acrylic resin (b) that does not have energy-ray curable groups, and the acrylic resin (b) has constituent units derived from 4-(meth)acryloylmorpholine. <11> Use of the protective film-forming film described above. <13> In the manufacture of chips with protective films, for forming a protective film on the side of the semiconductor wafer or semiconductor chip opposite to the circuit side, <11> or <12> Use of the protective film-forming film described above. <14> In the manufacturing of a face-down substrate device, a protective film is formed on the side of a semiconductor wafer or semiconductor chip opposite to the circuit side. <11> or <12> Use of the protective film-forming film described above. [Examples]

[0296] The present invention will be described in more detail below with reference to specific examples. However, the present invention is not limited in any way to the examples shown below.

[0297] <Raw materials for resin manufacturing> The full names of the resin manufacturing raw materials, which are abbreviated in this example and comparative example, are shown below. BA: n-butyl acrylate MA: Methyl acrylate ACrMO:4-Acryloylmorpholine HEA: 2-hydroxyethyl acrylate 2EHA: 2-ethylhexyl acrylate MMA: Methyl methacrylate

[0298] <Raw materials for manufacturing protective film-forming compositions> The raw materials used in the production of the protective film-forming composition are listed below. [Energy ray curing component (a)] (a)-1: ε-Caprolactone-modified tris-(2-acryloxyethyl)isocyanurate (A-9300-1CL, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., a trifunctional UV-curable compound) (a)-2: Urethane acrylate (KJ Chemicals "Quick cure 8100EA70")

[0299] [Acrylic resin without energy-ray curable groups (b)] (b)-1: Acrylic resin (weight-average molecular weight (700,000), glass transition temperature 2°C) which is a copolymer of BA (33 parts by mass), MA (27 parts by mass), ACrMO (25 parts by mass), and HEA (15 parts by mass).

[0300] [Photopolymerization initiator (c)] (c)-1:2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one (Omnirad® 379, manufactured by IGM Resins) (c)-2:2-Hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one (IGM Resins "Omnirad® 127D") (c)-3:1-Hydroxycyclohexylphenyl ketone (Omnirad® 184, manufactured by IGM Resins)

[0301] [Inorganic filler (d)] (d)-1: (d)-1: Silica filler (fused silica filler, average particle size 8 μm)

[0302] [Coloring agent (g)] (g)-1: Organic black pigment (Dainichi Seika Kogyo Co., Ltd. "6377 Black")

[0303] [General-purpose additive (z)] (z)-1: Hydroxyphenyltriazine-based UV absorber (BASF's "Tinuvin® 479," solid at 25°C).

[0304] <<Manufacturing of protective film-forming film>> [Example 1] <Manufacturing of protective film-forming composition (IV)-1> Energy-ray curable component (a)-1 (12.4 parts by mass), energy-ray curable component (a)-2 (10.1 parts by mass), acrylic resin without energy-ray curable groups (b)-1 (14.7 parts by mass), photopolymerization initiator (c)-1 (0.1 parts by mass), photopolymerization initiator (c)-2 (0.5 parts by mass), inorganic filler (d)-1 (58.4 parts by mass), colorant (g)-1 (3.0 parts by mass), and general-purpose additive (z)-1 (0.8 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain energy-ray curable protective film-forming composition (IV)-1, in which the total concentration of all components other than the solvent was 55% by mass. Note that the amounts of components other than the solvent shown herein are all amounts of the target product excluding the solvent, and are the same in the following protective film-forming composition (IV).

[0305] <Manufacturing of protective film-forming films> A release film (second release film, Lintec Corporation's "SP-PET382150", 38 μm thick) made of polyethylene terephthalate film, in which one side was peeled off by silicone treatment, was used. The protective film-forming composition (IV)-1 obtained above was applied to the peeled surface, and the film was dried at 100°C for 2 minutes to produce an energy ray-curable protective film-forming film with a thickness of 25 μm.

[0306] Furthermore, by laminating the release-treated surface of a release film (first release film, Lintec Corporation's "SP-PET381031", 38 μm thick) to the exposed surface of the obtained protective film-forming film that does not have a second release film, a protective film-forming film with a release film is obtained, comprising a protective film-forming film, a first release film provided on one side of the protective film-forming film, and a second release film provided on the other side of the protective film-forming film.

[0307] [Example 2] <Manufacturing of protective film-forming composition (IV)-2> Energy-ray curable component (a)-1 (12.4 parts by mass), energy-ray curable component (a)-2 (10.1 parts by mass), acrylic resin (b)-1 (14.7 parts by mass) without energy-ray curable groups, photopolymerization initiator (c)-2 (0.6 parts by mass), inorganic filler (d)-1 (58.4 parts by mass), colorant (g)-1 (3.0 parts by mass), and general-purpose additive (z)-1 (0.8 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain an energy-ray curable protective film-forming composition (IV)-2 in which the total concentration of all components other than the solvent was 55% by mass.

[0308] <Manufacturing of protective film-forming films> The protective film-forming film of Example 2 was manufactured in the same manner as in Example 1, except that protective film-forming composition (IV)-2 was used instead of protective film-forming composition (IV)-1.

[0309] [Example 3] <Manufacturing of protective film-forming composition (IV)-3> Energy-ray curable component (a)-1 (12.4 parts by mass), energy-ray curable component (a)-2 (10.1 parts by mass), acrylic resin (b)-1 (14.7 parts by mass) without energy-ray curable groups, photopolymerization initiator (c)-1 (0.1 parts by mass), photopolymerization initiator (c)-2 (0.5 parts by mass), inorganic filler (d)-1 (59.2 parts by mass), and colorant (g)-1 (3.0 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain an energy-ray curable protective film-forming composition (IV)-3 in which the total concentration of all components other than the solvent was 55% by mass.

[0310] <Manufacturing of protective film-forming films> The protective film-forming film of Example 3 was manufactured in the same manner as in Example 1, except that protective film-forming composition (IV)-3 was used instead of protective film-forming composition (IV)-1.

[0311] [Comparative Example 1] <Manufacturing of protective film-forming composition (X)-1> Energy-ray curable component (a)-1 (12.4 parts by mass), energy-ray curable component (a)-2 (10.1 parts by mass), acrylic resin (b)-1 (14.7 parts by mass) without energy-ray curable groups, photopolymerization initiator (c)-2 (0.1 parts by mass), inorganic filler (d)-1 (58.9 parts by mass), colorant (g)-1 (3.0 parts by mass), and general-purpose additive (z)-1 (0.8 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain an energy-ray curable protective film-forming composition (X)-1 in which the total concentration of all components other than the solvent was 55% by mass.

[0312] <Manufacturing of protective film-forming films> The protective film-forming film of Comparative Example 1 was manufactured in the same manner as in Example 1, except that protective film-forming composition (X)-1 was used instead of protective film-forming composition (IV)-1.

[0313] [Comparative Example 2] <Manufacturing of protective film-forming composition (X)-2> Energy-ray curable component (a)-1 (12.4 parts by mass), energy-ray curable component (a)-2 (10.1 parts by mass), acrylic resin (b)-1 (14.7 parts by mass) without energy-ray curable groups, photopolymerization initiator (c)-3 (0.1 parts by mass), inorganic filler (d)-1 (58.9 parts by mass), colorant (g)-1 (3.0 parts by mass), and general-purpose additive (z)-1 (0.8 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain an energy-ray curable protective film-forming composition (X)-2 in which the total concentration of all components other than the solvent was 55% by mass.

[0314] <Manufacturing of protective film-forming films> The protective film-forming film of Comparative Example 2 was manufactured in the same manner as in Example 1, except that protective film-forming composition (X)-2 was used instead of protective film-forming composition (IV)-1.

[0315] [Comparative Example 3] <Manufacturing of protective film-forming composition (X)-3> Energy-ray curable component (a)-1 (12.4 parts by mass), energy-ray curable component (a)-2 (10.1 parts by mass), acrylic resin (b)-1 (14.7 parts by mass) without energy-ray curable groups, photopolymerization initiator (c)-1 (0.1 parts by mass), photopolymerization initiator (c)-2 (0.5 parts by mass), inorganic filler (d)-1 (54.2 parts by mass), colorant (g)-1 (3.0 parts by mass), and general-purpose additive (z)-1 (5.0 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain an energy-ray curable protective film-forming composition (X)-3 in which the total concentration of all components other than the solvent was 55% by mass.

[0316] <Manufacturing of protective film-forming films> The protective film-forming film of Comparative Example 3 was manufactured in the same manner as in Example 1, except that protective film-forming composition (X)-3 was used instead of protective film-forming composition (IV)-1.

[0317] <<Evaluation of protective film-forming film>> <Measurement of the indentation depth and rate of change of the protective film-forming film> Regarding the protective film-forming film obtained above, at an illuminance of 220 mW / cm² 2 , light intensity 500mJ / cm 2 Under these conditions, a protective film was fabricated by irradiating with ultraviolet light at a wavelength of 365 nm. The indentation depth (μm) of the protective film-forming film before and after curing was measured using an ultra-micro hardness tester (Shimadzu Dynamic Ultra-Micro Hardness Tester DUH-211, manufactured by Shimadzu Corporation) under the following conditions. Indenter: Triangular pyramidal shape with a tip radius of curvature of 0.1 μm or less. Measurement mode: Load-unload test Maximum load: 10mN Holding time when maximum load is reached: 5 seconds Load speed: 0.14mN / sec Temperature: 23℃

[0318] Next, the difference between the indentation depth of the protective film-forming film after curing and the indentation depth of the protective film-forming film before curing was calculated using the following formula (1), and this was defined as the rate of change in the indentation depth of the protective film-forming film. The percentage change in indentation depth [%] = {(indentation depth of protective film before curing - indentation depth of protective film after curing) / indentation depth of protective film before curing} × 100 ... (1) The results of the indentation depth of the protective film and its rate of change are shown in Tables 1 and 2.

[0319] <Measurement of peel strength of protective film-forming film> The second release film was removed from the protective film-forming film with release film obtained above. The exposed surface of the protective film-forming film was attached to the polished surface of a 6-inch silicon wafer (350 μm thick, #2000 polished) at 70°C and 0.3 MPa, thereby creating a first laminated sheet in which the second release film, protective film-forming film, and wafer were stacked in this order in the thickness direction (the above-mentioned attachment step). After the first laminated sheet has stood for 20 minutes, apply an illuminance of 220 mW / cm² from the side of the second release film. 2 , Light amount: 500mJ / cm 2The materials were irradiated with UV light to produce a second laminated sheet in which the second release film, protective film, and wafer were stacked in this order in the thickness direction (the curing step). Next, the second release film was peeled off the second laminated sheet, and the protective film and wafer were divided into quarters using a ceramic cutter to produce a third laminated sheet that was one-quarter the size of the second laminated sheet (the dividing step). Dicing tape (Lintec "ADWILL D-833W") was attached to the exposed surface of the protective film in the third laminated sheet, and 10 mm wide strips were cut into the protective film and the dicing tape from the dicing tape side using a utility knife. Subsequently, a tensile test was performed using a precision universal testing machine (Shimadzu Corporation "Autograph AG-IS") to peel the dicing tape and protective film from the wafer under the conditions of a peel angle of 90°, a measurement temperature of 23°C, and a tensile speed of 50 mm / second. The load at this time was measured and defined as the peel force between the cured protective film-forming film (protective film) and the wafer (peel strength of the protective film-forming film). The peel strength of the protective film-forming film was evaluated according to the following criteria. A: The peel strength was 3.5-10 N / 10 mm. B: The peel strength was less than 3.5 N / 10 mm or greater than 10 N / 10 mm. The results of the evaluation of the peel strength of the protective film are shown in Tables 1 and 2.

[0320] [Manufacturing of support sheets with release film] A polymer component (solids) (100 parts by mass), a tolylene diisocyanate crosslinking agent (Toyo Chem Co., Ltd. "BHS-8515") (solids) (10 parts by mass), and a hexamethylene diisocyanate crosslinking agent (Tosoh Corporation "Coronate HL") (7.5 parts by mass) (solids) (100 parts by mass) were dissolved or dispersed in methyl ethyl ketone, and the solids concentration was adjusted to 30% by mass to obtain an adhesive composition. The polymer component is an acrylic copolymer with a weight-average molecular weight of 600,000 and a glass transition temperature of -11°C, obtained by copolymerizing 80 parts by mass of 2-ethylhexyl methacrylate (2EHMA) and 20 parts by mass of 2-hydroxyethyl acrylate (HEA).

[0321] The adhesive composition was applied to the release surface of a release film (Lintec Corporation's "SP-PET382150", 38 μm thick) using a knife coater and dried at 110°C for 2 minutes to form an adhesive layer (5 μm thick after drying). The glossy side of a separate polypropylene film (80 μm thick, Gunze Corporation's "Funclear® LPD #80", glossy side surface roughness 0.1 μm, matte side surface roughness 0.3 μm) was then laminated to the exposed surface (the surface opposite to the side with the release film) to obtain a support sheet with a release film consisting of a base material / adhesive layer / release film.

[0322] [Fabrication of composite sheets for protective film formation] The release film was removed from the support sheet with the release film obtained above. The first release film was also removed from the protective film forming film obtained above. Then, by laminating the exposed surface of the adhesive layer resulting from the removal of the release film with the exposed surface of the protective film forming film resulting from the removal of the first release film, a composite sheet for forming a protective film was prepared in which the substrate, adhesive layer, protective film forming film, and second release film were laminated in this order in the thickness direction.

[0323] <Reliability testing of protective film-forming films> The second release film was removed from the obtained protective film-forming composite sheet. The protective film-forming composite sheet, with the protective film-forming film exposed, was attached to the polished surface of a 6-inch silicon wafer (350 μm thick, #2000 polished) at 70°C and 0.3 MPa to produce a first laminated composite sheet in which the support sheet, protective film-forming film, and wafer were stacked in this order in the thickness direction (the above attachment step). After the first laminated composite sheet has stood for 20 minutes, an illuminance of 220 mW / cm² was measured from the side of the support sheet. 2 , Light amount: 500mJ / cm 2A second laminated composite sheet was fabricated by UV irradiation, in which a support sheet, protective film, and wafer were stacked in this order in the thickness direction (the curing step). Next, a silicon wafer was divided under the following conditions using a dicing device (DISCO "DFD6362"), and the protective film was cut to fabricate a third laminated composite sheet in which a 3mm x 3mm chip with a protective film was fixed on a support sheet (the dividing step). Dicing speed: 30mm / sec Blade rotation speed: 50,000 rpm Blade height: 60 μm Blade part number: Z05-SD2000-N1-90 CC (manufactured by Disco)

[0324] The protective film-coated chip in the third laminated composite sheet was picked up by separating it from the support sheet (the pickup step). Next, the chips with the protective coating were transferred to a metal basket and dried in an oven (ESPEC SPH-201) at 125°C for 24 hours. The protective film-coated chips were removed from the oven and left to stand for 168 hours in a humid heat environment of 85°C / 85%RH to undergo humid heat treatment. After removing the humid heat-treated protective film-coated chips from the constant temperature and humidity chamber, they were subjected to a reflow oven (STR-2010M, manufactured by Senju Metal Industries Co., Ltd.) for 10 minutes at a maximum temperature of 260°C and a speed of 0.22 m / min. Next, the heat-treated chips with protective coatings were subjected to a temperature cycle consisting of a low-temperature treatment (i) followed by a high-temperature treatment (ii) using a small thermal shock device (ESPEC "TSE-11-A"). This temperature cycle was repeated 1000 times. The low-temperature treatment (i) involved exposing the heat-treated chips with protective coatings obtained above to a low temperature of -40°C for a holding time of 10 minutes, and the high-temperature treatment (ii) involved exposing the chips with protective coatings after the low-temperature treatment (i) to a high temperature of 125°C for a holding time of 10 minutes. The temperature cycle was performed in accordance with JEDEC Condition C. Next, an ultrasonic microscope (Sonoscan "D9600 C-SAM") was used to check for peeling of the protective film from the chip, and the reliability of the protective film-forming film was evaluated according to the following criteria. A: No chips with peeling of the protective film were observed, indicating excellent reliability. B: Chips with peeling protective coatings were found, resulting in lower reliability. The results of the reliability evaluation of the protective film are shown in Tables 1 and 2.

[0325] In addition, a "-" in the "Components" column of Tables 1 and 2 indicates that the protective film does not contain that component.

[0326] [Table 1]

[0327] [Table 2]

[0328] As is clear from the results above, the protective film-forming films of Examples 1 to 3 exhibited a large rate of change in indentation depth before and after curing, high peel strength, and excellent adhesive reliability.

[0329] The protective film of Comparative Example 1 exhibited a small change in indentation depth before and after curing, low peel strength, and poor adhesive reliability.

[0330] The protective film in Comparative Example 2 exhibited a small change in indentation depth before and after curing, low peel strength, and poor adhesive reliability.

[0331] The protective film in Comparative Example 3 exhibited a small change in indentation depth before and after curing, low peel strength, and poor adhesive reliability. [Industrial applicability]

[0332] This invention can be used in the manufacture of various substrate devices, including semiconductor devices. [Explanation of Symbols]

[0333] 10,20...Support sheet, 10a,20a...One side of the support sheet (first side), 11...Substrate, 12...Adhesive layer, 13,23...Energy ray curable protective film-forming film, 13'...Protective film, 13b'...Other side of the protective film (second side), 130'...Protective film after cutting. 101, 102, 103, 104… Composite sheets for forming protective films, 501...First laminated composite sheet, 502...Second laminated composite sheet, 503...Third laminated composite sheet, 601…First layered film, 602…Second layered film, 603…Third layered film, 8…Dicing sheet, 9…Wafer, 9b…Back side of wafer, 90…Chip, 90b…Back side of chip, 901…Chip with protective film

Claims

1. An energy ray curable protective film-forming film, A protective film-forming film wherein the rate of change in indentation depth, as measured by the method for measuring the rate of change in indentation depth of the protective film-forming film described below, is 60% or more. <Method for measuring the rate of change in indentation depth> Regarding the protective film forming film, the illuminance is 220 mW / cm². ２ , light intensity 500mJ / cm ２ Under these conditions, ultraviolet light with a wavelength of 365 nm is irradiated to produce a protective film after curing. The indentation depth (μm) of the protective film-forming film before and after curing is measured using an ultra-micro hardness tester under the following conditions. Indenter: Triangular pyramidal shape with a tip radius of curvature of 0.1 μm or less. Measurement mode: Load-unload test Maximum load: 10 mN Holding time when maximum load is reached: 5 seconds Loading speed: 0.14mN / sec Temperature: 23℃ Next, the difference between the indentation depth of the protective film-forming film after curing and the indentation depth of the protective film-forming film before curing is calculated using the following formula (1), and this is defined as the rate of change in the indentation depth of the protective film-forming film. Change in indentation depth [%] = {(Indentation depth of protective film before curing - Indentation depth of protective film after curing) / Indentation depth of protective film before curing} × 100 ... (1) ... (1)

2. The protective film-forming film according to claim 1, wherein the protective film-forming film contains an acrylic resin (b) that does not have energy-ray curable groups, and the acrylic resin (b) has constituent units derived from 4-(meth)acryloylmorpholine.

3. A composite sheet for forming a protective film, comprising a support sheet and a protective film forming film provided on one surface of the support sheet, A composite sheet for forming a protective film, wherein the protective film forming film is the protective film forming film according to claim 1 or 2.

4. A kit comprising: a first laminate in which a first release film and a protective film forming film are laminated in this order; and a support sheet used to support the workpiece to which the protective film forming film is to be attached and the protective film forming film, A kit wherein the protective film forming film is the protective film forming film according to claim 1 or 2.

5. The use of a protective film-forming film for forming a protective film on the side of a semiconductor wafer or semiconductor chip opposite to the circuit side, Use of a protective film-forming film, wherein the protective film-forming film is the protective film-forming film described in claim 1 or 2.

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