Protective film forming film, composite sheet for forming protective film, method for manufacturing a workpiece with a protective film, and method for manufacturing a workpiece with a protective film.

Abstract

To provide: a protective film-forming film which is thermally curable and which can make scars on a surface of the protective film existing after thermal cure of the protective film-forming film inconspicuous even when the scars have been formed on the surface of the protective film-forming film; a composite sheet for forming the protective film including the protective film-forming film; a production method of a work with the protective film by using the protective film-forming film or the composite sheet for forming the protective film; and a production method of a processed article of the work with the protective film.SOLUTION: A protective film-forming film 13 is thermally curable. When a test piece with a width of 4 mm is supported at two places spaced by an interval of 20 mm and a storage elastic modulus E' of the test piece is measured under a condition of frequency of 11 Hz, rate of temperature increase of 3°C / min in a tension mode while rising temperature of the test piece from -50°C to 150°C in a condition of constant temperature increase, the storage elastic modulus E'(90) of the test piece at 90°C is 5 MPa or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Semiconductor wafers and insulating wafers have circuits formed on one side (the circuit side), and some of these wafers have protruding electrodes such as bumps on that side (the circuit side). Such wafers are divided into chips, and their protruding electrodes are connected to connection pads on a circuit board, 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 may be laminated on a support sheet and used as a composite sheet for protective film formation, or it may be used without being laminated on a support sheet (see Patent Document 1). Next, the wafer with the protective film-forming film on its back surface (wafer with protective film-forming film) is processed through various subsequent processes to become a chip with a protective film on its back surface (chip with protective film). During this time, the wafer with the protective film-forming film needs to be transported to the desired location, such as the place where the next process will be performed or where it will be stored.

[0004] The aforementioned chip with protective film can be manufactured, for example, by first producing a wafer with the protective film forming film, then dividing the wafer to produce chips, cutting the protective film forming film to produce chips with the cut protective film forming film on the back surface (chips with protective film forming film), picking up the chips with protective film forming film, and then further curing the cut protective film forming film to form a protective film. Alternatively, the chips with protective film can be picked up after curing the cut protective film forming film to form chips with protective film.

[0005] Furthermore, the chip with the protective film can also be manufactured, for example, by first creating a wafer with the protective film forming film, then curing the protective film forming film within it to form a protective film, then dividing the wafer to create chips, and finally cutting the protective film. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2015 / 111632 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] As the aforementioned protective film-forming film, thermosetting protective film-forming films that can form a protective film by heating and heat-curing are widely used. When attaching a thermosetting protective film-forming film to the back surface of a workpiece, it is pressed from the side of the protective film-forming film that is not facing the workpiece using a pressing means such as a laminating roll via a release film or support sheet. In this case, for example, if particulate foreign matter is mixed between the release film or support sheet and the laminating roll, the pressure marks of the particulate foreign matter may be formed on the surface of the protective film-forming film that is not facing the workpiece.

[0008] When transporting a workpiece with a protective film, such as a wafer with a protective film, the transport means is brought into contact with the exposed surface of the protective film on the side opposite to the workpiece, and the workpiece with the protective film is transported while being fixed in place by the transport means. As for the aforementioned transport means, for example, one known method is to fix the workpiece with the protective film attached by adsorption at the contact point with the workpiece, but this is just one example. When a workpiece with a protective film is transported using such a transport means, contact marks from the transport means (the fixing part) may be formed on the parts of the protective film that are fixed by the transport means, more specifically, on the parts of the transport means that come into contact with the fixing part. For example, if the fixing part is a suction cup with a circular planar shape, circular suction marks may be formed on the exposed surface of the protective film.

[0009] Furthermore, when a chip with a protective film is picked up using a push-up mechanism such as a push-up needle pin, indentations (needle marks) may be formed on the protective film at the point where it was pushed up by the push-up mechanism.

[0010] Scratch marks such as indentations, contact marks, suction marks, and dents form on the surface of protective film-forming films because the protective film-forming film is relatively soft. Workpieces with protective film-forming films that have clearly visible scratches have aesthetic problems and raise concerns about reduced laser printability. Even after the protective film-forming film has heat-cured and formed a protective film, workpieces with clearly visible scratches still have aesthetic problems and raise concerns about reduced laser printability. Furthermore, the protective film-forming film disclosed in Patent Document 1 does not necessarily solve these problems.

[0011] The present invention aims to provide a thermosetting protective film-forming film that can make scratches on the surface of the protective film less noticeable even when scratches are formed on the surface of the protective film-forming film, a composite sheet for forming a protective film equipped with the protective film, a method for manufacturing a workpiece with a protective film using the protective film-forming film or the composite sheet for forming a protective film, and a method for manufacturing a workpiece with a protective film. [Means for solving the problem]

[0012] The present invention includes the following embodiments. [1] A thermosetting protective film, A protective film-forming film in which a 4 mm wide test piece of the protective film-forming film is held at two locations with a 20 mm gap between them, and the storage modulus E' of the test piece is measured while the test piece is heated from -50°C to 150°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the storage modulus E' of the test piece at 90°C is 5 MPa or less. [2] The protective film forming film according to [1], wherein a 4 mm wide test piece of the protective film forming film is held at two locations with a 20 mm gap between them, and the tanδ of the test piece is measured while the test piece is heated from -50°C to 150°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the tanδ of the test piece at 90°C is 0.34 or more.

[0013] [3] The protective film forming film according to [1] or [2], wherein a 5 mm wide test piece of a thermoset product obtained by heat curing the protective film forming film is held at two locations with a 20 mm gap between them, and the storage modulus E' of the test piece is measured while heating the test piece from -60°C to 300°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the storage modulus E'(23) of the test piece at 23°C is 100 MPa or more. [4] Contains polymer component (A) including acrylic resin, The protective film-forming film according to any one of [1] to [3], wherein the glass transition temperature of the acrylic resin is less than 10°C. [5] Containing filler (D), The protective film-forming film according to any one of [1] to [4], wherein the ratio of the content of the filler (D) to the total mass of the protective film-forming film is less than 50% by mass.

[0014] [6] 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 any one of [1] to [5].

[0015] [7] A method for manufacturing a work with a protective film, The work with a protective film includes a work and a protective film provided at any location on the work. The manufacturing method includes an attaching step of attaching the protective film-forming film according to any one of [1] to [5] or the protective film-forming film in the composite sheet for forming a protective film according to [6] to the target location of the work to produce a work with a protective film-forming film including the work and the protective film-forming film, After the attaching step, a thermosetting step of thermosetting the protective film-forming film to form the protective film to produce the work with a protective film. [8] A method for manufacturing a processed product of a work with a protective film, The processed product of a work with a protective film includes a processed work obtained by processing a work and a protective film provided at any location on the processed work. The manufacturing method includes an attaching step of attaching the protective film-forming film according to any one of [1] to [5] or the protective film-forming film in the composite sheet for forming a protective film according to [6] to the target location of the work to produce a work with a protective film-forming film including the work and the protective film-forming film, After the pasting step, a processing step of producing the workpiece by processing the workpiece is performed. After the pasting step, a thermosetting step of forming the protective film by thermosetting the protective film - forming film is included, and a method for manufacturing a workpiece with a protective film.

Effects of the Invention

[0016] According to the present invention, there are provided a protective film - forming film which is a thermosetting protective film - forming film and can make scratches on the surface of the protective film after thermosetting the protective film - forming film less noticeable even when scratches are formed on the surface of the protective film - forming film, a composite sheet for forming a protective film including the protective film - forming film, a method for manufacturing a workpiece with a protective film using the protective film - forming film or the composite sheet for forming a protective film, and a method for manufacturing a processed workpiece with a protective film.

Brief Description of the Drawings

[0017] [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 a 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 a 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 a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 6] It is a cross - sectional view for schematically explaining an example of a method for manufacturing a wafer with a protective film according to an embodiment of the present invention. [Figure 7] It is a cross - sectional view for schematically explaining another example of a method for manufacturing a wafer with a protective film according to an embodiment of the present invention. [Figure 8]This is a schematic cross-sectional view illustrating an example of a method for manufacturing a chip with a protective film according to one embodiment of the present invention. [Figure 9] This is a schematic cross-sectional view illustrating another example of a method for manufacturing a chip with a protective film according to one embodiment of the present invention. [Modes for carrying out the invention]

[0018] ◇ Protective film A protective film-forming film according to one embodiment of the present invention is a thermosetting protective film-forming film in which a 4 mm wide test piece of the protective film-forming film is held at two locations with a 20 mm gap between them, and the storage modulus E' of the test piece is measured while the test piece is heated from -50°C to 150°C under the conditions of constant heating at a frequency of 11 Hz and a heating rate of 3°C / min in tensile mode, and the storage modulus E'(90) of the test piece at 90°C is 5 MPa or less. The protective film-forming film of this embodiment can be laminated with a support sheet, for example, as described later, to form a composite sheet for forming a protective film.

[0019] By using the protective film-forming film of this embodiment, or a composite sheet for forming a protective film that includes the same, a workpiece with a protective film can be manufactured, comprising a workpiece and a protective film provided on any part of the workpiece. Furthermore, a workpiece with a protective film can be manufactured, comprising a workpiece and a protective film provided on any part of the workpiece. For example, if the workpiece is a wafer, a chip with a protective film can be manufactured, comprising a chip and a protective film provided on the back surface of the chip, by using the protective film-forming film or the composite sheet for forming a protective film.

[0020] In this embodiment, examples of workpieces include semiconductor wafers and semiconductor device panels. A semiconductor device panel is handled in the manufacturing process of a semiconductor device, and a specific example is a semiconductor device in which one or more electronic components are sealed with a sealing resin, and multiple such semiconductor devices are arranged planarly within a circular, rectangular, or other shaped area. In this specification, a processed workpiece is referred to as a "workpiece product." For example, if the workpiece is a semiconductor wafer, a semiconductor chip is an example of a workpiece product.

[0021] 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 processed (divided) by means of dicing or other methods to form chips. 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." It is preferable that protruding electrodes, such as bumps and pillars, are provided on both the circuit surface of the wafer and the circuit surface of the chip. It is preferable that the protruding electrodes are made of solder.

[0022] Furthermore, by using the aforementioned protective film-coated chip, a substrate device can be manufactured. In this specification, "substrate device" means a device constructed by flip-chip connecting a workpiece with a protective film 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 workpiece, the substrate device may be a semiconductor device consisting of semiconductor chips with protective films that are flip-chip connected.

[0023] In this embodiment, the protective film-forming film has a storage modulus E'(90) of the test piece at 90°C of 5 MPa or less. Therefore, even if scratches are formed on the surface of the thermosetting protective film-forming film during the process of manufacturing the protective film-coated workpiece or the workpiece processed product with the protective film using the protective film-forming film of this embodiment, the scratches on the surface of the protective film after the protective film-forming film has been heat-cured can be made less noticeable. In this embodiment, the protective film-forming film has a storage modulus E'(90) of the test piece at 90°C of 5 MPa or less. Therefore, when the protective film-forming film is heat-cured to form a protective film, the fluidity of the protective film-forming film at 90°C before heat curing is increased compared to room temperature, and scratches formed on the surface of the protective film-forming film can be repaired. In other words, the protective film-forming film of this embodiment has excellent self-healing properties, and as a result, scratches on the surface of the protective film can be made less noticeable. In this specification, "room temperature" means a temperature that is neither cooled nor heated, i.e., a normal temperature, such as 15-25°C.

[0024] The protective film-forming film of this embodiment has a storage modulus E'(90) of the test piece at 90°C of 5 MPa or less, preferably 3 MPa or less, more preferably 2 MPa or less, even more preferably 0.4 MPa or less, and particularly preferably 0.2 MPa or less.

[0025] The protective film-forming film of this embodiment is thermosetting and functions as a protective film through its thermosetting. A protective film-forming film at room temperature is heated to a temperature of 100°C or higher, and then cooled to room temperature to obtain a heated and cooled protective film-forming film. When the hardness of the heated and cooled protective film-forming film is compared to the hardness of the protective film-forming film before heating at the same temperature, if the heated and cooled protective film-forming film is harder, then this protective film-forming film is thermosetting.

[0026] The protective film forming in this embodiment preferably does not harden at 90°C, but rather softens. Specifically, when a 4 mm wide test piece of the protective film forming film is held at two locations with a 20 mm gap between them, and the storage modulus E' of the test piece is measured while heating the test piece from -50°C to 150°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, it is preferable that the storage modulus E'(90) of the test piece is smaller than the storage modulus E'(70) of the test piece at 70°C.

[0027] In this embodiment, the protective film forming film preferably has a storage modulus E'(70) of the test piece at 70°C of 8 MPa or less, more preferably 3.5 MPa or less, even more preferably 3 MPa or less, and particularly preferably 2 MPa or less.

[0028] In this embodiment, when a 4 mm wide test piece of the protective film-forming film is held at two locations with a 20 mm gap between them, and the test piece is heated from -50°C to 150°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, the tanδ of the test piece is measured, it is preferable that the tanδ(90) of the test piece at 90°C is 0.20 or higher, more preferably 0.24 or higher, and even more preferably 0.34 or higher. When the value of tanδ(90) of the test piece at 90°C is above the lower limit, the self-healing properties of the protective film-forming film tend to be superior. This is presumed to be because the contribution of the viscous component of the protective film-forming film becomes larger at 90°C.

[0029] In this embodiment, when a 4 mm wide test piece of the protective film-forming film is held at two locations with a 20 mm gap between them, and the test piece is heated from -50°C to 150°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, the tanδ of the test piece is measured, it is preferable that the tanδ(70) of the test piece at 70°C is 0.35 or higher, more preferably 0.40 or higher, and even more preferably 0.50 or higher. When the value of tanδ(70) of the test piece at 70°C is above the lower limit, the self-healing properties of the protective film-forming film tend to be superior. This is presumed to be because the contribution of the viscous component of the protective film-forming film becomes larger at 70°C.

[0030] When a 5 mm wide test piece of the heat-cured protective film of this embodiment is held at two locations with a 20 mm gap between them, and the storage modulus E' of the test piece is measured while heating the test piece from -60°C to 300°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, the storage modulus E'(23) of the test piece at 23°C is preferably 100 MPa or more, more preferably 200 MPa or more, and even more preferably 300 MPa or more. If the storage modulus E'(23) of the heat-cured protective film is too low, when a workpiece with a protective film, such as a chip with a protective film, is packed on a carrier tape and transported, the soft protective film may hit the inner wall of the carrier tape, potentially causing scratches or dents. Furthermore, in the process of picking up the chip with the protective film after curing, a higher storage modulus E'(23) of the heat-cured protective film reduces needle marks during pickup.

[0031] 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. The protective film is preferably made of one layer (single layer) from the viewpoint of ease of controlling the storage modulus E' and manufacturing cost.

[0032] 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."

[0033] The storage modulus E' of a test specimen of a protective film-forming film can be measured by creating a 4 mm wide laminate by laminating and cutting multiple protective film-forming films, and then measuring this laminate as a test specimen.

[0034] The storage modulus E' of a protective film test specimen can be measured by preparing a 5mm wide laminate by laminating and cutting multiple protective film-forming films, then heating and curing this laminate to form a protective film laminate, and finally measuring the storage modulus E' of the protective film as a test specimen. Alternatively, the storage modulus E' of the protective film can be measured by preparing a 4mm wide laminate by laminating and heating and curing multiple protective film-forming films to form a protective film, and then cutting this laminate to form a test specimen.

[0035] More specifically, the test specimen is held in two locations with a 20 mm gap between them, and in this state, the storage modulus E' of the test specimen is measured while the specimen is heated at a constant rate of 3 °C / min from -10 °C to 170 °C at a frequency of 11 Hz. Holding the test specimen in two locations with a 20 mm gap between them means that the length of the portion of the test specimen from which the storage modulus E' is measured is 20 mm.

[0036] The test specimen can be held at the two locations mentioned above, for example, using a known gripping device or other holding means.

[0037] The thickness of the test specimen (laminate) is not particularly limited, as long as it does not hinder the performance of the test and does not impair the measurement accuracy of the storage modulus E'. Typically, the thickness of the test specimen is preferably 190 to 210 μm, more preferably 195 to 205 μm, and particularly preferably 200 μm.

[0038] The number of protective film-forming films constituting the test specimen is not particularly limited and can be arbitrarily selected according to the thickness of each protective film-forming film. For example, the test specimen can be prepared by using five protective film-forming films or protective films, each with a thickness of 40 μm. However, this is just one example, and the number and thickness of protective film-forming films or protective films used are not limited to this.

[0039] The storage modulus E'(90) and storage modulus E'(70) of the test specimen can be adjusted by adjusting the type and content of the components contained in the protective film-forming film. For example, if the protective film-forming film contains a polymer component (A) described later, the storage modulus E' of the test specimen can be more easily adjusted by adjusting the type and amount of constituent units of the polymer component (A). More specifically, for example, by using an acrylic resin having a certain amount or more of constituent units derived from 2-ethylhexyl acrylate as the polymer component (A) and adjusting its content, the storage modulus E' of the test specimen can be more easily adjusted.

[0040] When polymer component (A) includes acrylic resin, the storage modulus E' of the test specimen can be more easily adjusted by controlling the glass transition temperature of the acrylic resin. The lower the glass transition temperature of the acrylic resin, the smaller the storage modulus E'(90) and storage modulus E'(70) of the test specimen tend to be. Furthermore, for example, if the protective film-forming film contains a filler (D) described later, the storage modulus E'(90) and storage modulus E'(70) of the test specimen can be more easily adjusted by using surface-modified spherical filler (D) and adjusting the average particle size and content. Typically, the larger the average particle size of the filler (D), the smaller the storage modulus E'(90) and storage modulus E'(70) of the test specimen tend to be.

[0041] The thickness of the protective film is preferably less than 50 μm, and more preferably less than 45 μm.

[0042] The thickness of the protective film is preferably 10 μm or more, more preferably 15 μm or more, and may be, for example, 20 μm or more, in order to form a protective film with higher protective performance.

[0043] The thickness of the protective film can be appropriately adjusted within a range set by arbitrarily combining any of the upper and lower limits described above. For example, in one embodiment, the thickness of the protective film may be either 5 μm or more and less than 50 μm, or 5 μm or more and less than 45 μm.

[0044] In this specification, "thickness of protective film" means the total thickness of the protective film. For example, the thickness of a protective film consisting of multiple layers means the total thickness of all layers constituting the protective film.

[0045] In this specification, "thickness," unless otherwise specified, refers to the average of the thicknesses measured at five randomly selected locations on the object, and can be obtained using a constant-pressure thickness measuring instrument in accordance with JIS K7130.

[0046] In this embodiment, it is preferable that the thermoset product obtained by heating the protective film-forming film functions as a protective film.

[0047] The curing conditions when the protective film-forming film is attached to the desired location on the wafer and heat-cured to form a protective 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.

[0048] For example, the heating temperature during the heat curing of the protective film is preferably 100 to 180°C, more preferably 110 to 160°C, and particularly preferably 120 to 140°C. The heating time during the heat curing is preferably 0.5 to 5 hours, more preferably 0.5 to 4 hours, and particularly preferably 1 to 3 hours.

[0049] <<Composition for forming protective film>> The protective film-forming film can be formed using a protective film-forming composition (more specifically, a thermosetting protective film-forming composition) containing its constituent materials. For example, the protective film-forming film can be formed by coating the surface to be formed with the protective film-forming composition and drying it as necessary.

[0050] The protective film forming the aforementioned protective film may have energy ray curability in addition to thermosetting properties.

[0051] In this specification, "energy beam" means an electromagnetic wave or charged particle beam that has an energy quantum, and examples 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.

[0052] 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.

[0053] 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. When a protective film-forming composition containing a solvent is heat-dried, it is preferable to heat-dry it at, for example, 70 to 130°C for 10 seconds to 5 minutes. However, since the protective film-forming composition is thermosetting, it is preferable to heat-dry it in a way that prevents the composition itself and the thermosetting protective film-forming film formed from it from becoming thermosetting.

[0054] Preferred protective film-forming films include, for example, those containing a polymer component (A), a thermosetting component (B), and a filler (D). Polymer component (A) is a component that can be considered to have been formed by a polymerization reaction of polymerizable compounds. Thermosetting component (B) is a component that can undergo a curing (polymerization) reaction triggered by heat. In this specification, polymerization reactions also include polycondensation reactions. The composition of the protective film-forming composition will be described in detail below.

[0055] <Protective film forming composition (III)> Examples of preferred protective film-forming compositions include protective film-forming composition (III) (which may be simply referred to as "composition (III)" in this specification) containing the polymer component (A), thermosetting component (B), and filler (D).

[0056] [Polymer component (A)] Polymer component (A) is a polymer compound that imparts film-forming properties, flexibility, and other characteristics to the protective film-forming film. In this specification, the polymer compound also includes products of polycondensation reactions.

[0057] The polymer component (A) contained in composition (III) 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.

[0058] Examples of polymer component (A) include acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin, etc., with acrylic resin being preferred.

[0059] Examples of the acrylic resin in polymer component (A) include known acrylic polymers. The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, more preferably 1,000,000 to 1,500,000, even more preferably 200,000 to 1,200,000, and particularly preferably 300,000 to 1,000,000. Having a weight-average molecular weight of the acrylic resin above the lower limit makes it easier to impart film-forming properties. Having a weight-average molecular weight of the acrylic resin below the upper limit makes it easier to reduce the storage modulus E'(90) and the storage modulus E'(70).

[0060] In this specification, "weight-average molecular weight" refers to the polystyrene equivalent value measured by gel permeation chromatography (GPC) unless otherwise specified.

[0061] The glass transition temperature (Tg) of the acrylic resin is preferably -80°C or higher and less than 10°C, more preferably -70°C or higher and 5°C or lower, even more preferably -60°C or higher and 0°C or lower, and particularly preferably -60°C or higher and -5°C or lower. When the Tg of the acrylic resin is above the lower limit, for example, the adhesion between the thermoset product of the protective film-forming film and the support sheet is suppressed, and the peelability of the support sheet is moderately improved. When the Tg of the acrylic resin is below the upper limit, it becomes easier to make the storage modulus E'(90) and the storage modulus E'(70) smaller.

[0062] If an acrylic resin has m constituent units (where m is an integer greater than or equal to 2), and each of the m monomers that derive these constituent units is sequentially assigned a unique number from 1 to m and named "monomer m", then the glass transition temperature (Tg) of the acrylic resin can be calculated using Fox's formula shown below.

[0063]

number

[0064] [Number] (In the formula, m and W k are the same as those described above.)

[0065] Regarding the above Tg k as the value described in the Polymer Data Handbook, Adhesive Handbook, Polymer Handbook, etc. can be used. For example, the Tg k of the homopolymer of methyl acrylate is 10 °C, and the Tg k of the homopolymer of methyl methacrylate is 105 °C, and the Tg k of the homopolymer of 2-hydroxyethyl acrylate is -15 °C, and the Tg k of the homopolymer of glycidyl methacrylate is 41 °C, and the Tg k of the homopolymer of 2-ethylhexyl acrylate is -70 °C, and the Tg k of the homopolymer of acrylic acid is 103 °C, and the Tg k of the homopolymer of acrylonitrile is 97 °C, and the Tg k of the homopolymer of n-butyl acrylate is -54 °C, and the Tg k of the homopolymer of 2-ethylhexyl methacrylate is -10 °C, and the Tg k of the homopolymer of ethyl acrylate is -24 °C.

[0066] Examples of the acrylic resin include polymers of one or more (meth)acrylic acid esters; copolymers of two or more monomers selected from the above (meth)acrylic acid esters, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, etc. When there are two or more monomers constituting the acrylic resin, their combinations and ratios can be arbitrarily selected.

[0067] Examples of the (meth)acrylic acid esters constituting the acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and (meth Alkyl methacrylates such as isononyl acrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate (lauryl methacrylate), tridecyl methacrylate, tetradecyl methacrylate (myristyl methacrylate), pentadecyl methacrylate, hexadecyl methacrylate (palmityl methacrylate), heptadecyl methacrylate, octadecyl methacrylate (stearyl methacrylate), etc., in which the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms; Cycloalkyl esters of (meth)acrylate 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; (meth)acrylate cycloalkenyloxyalkyl esters such as (meth)acrylate dicyclopentenyloxyethyl ester; (meth)acrylimide; Glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; Hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and other hydroxyl group-containing (meth)acrylate esters; Examples include (meth)acrylic acid esters containing substituted amino groups, such as N-methylaminoethyl (meth)acrylate. Here, "substituted amino group" refers to a group having a structure in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom.

[0068] 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)acryloyl group" is a concept that encompasses both "acryloyl group" and "methacryloyl group," and "(meth)acrylate" is a concept that encompasses both "acrylate" and "methacrylate."

[0069] The acrylic resin may have functional groups that can bond with other compounds, such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups. The functional groups of the acrylic resin may be bonded to other compounds via a crosslinking agent (F) described later, or they may be directly bonded to other compounds without the crosslinking agent (F).

[0070] An example of a preferred acrylic resin is an acrylic resin (α) having a structural unit derived from 2-ethylhexyl acrylate.

[0071] In the acrylic resin (α), the ratio (content) of the constituent units derived from 2-ethylhexyl acrylate to the total amount of constituent units constituting the acrylic resin (α) is preferably 10 to 90% by mass, and may be, for example, 25 to 85% by mass, 40 to 80% by mass, or 50 to 75% by mass.

[0072] In the present invention, a thermoplastic resin other than acrylic resin (hereinafter sometimes simply referred to as "thermoplastic resin") may be used as the polymer component (A) alone without using acrylic resin, or in combination with acrylic resin. Using the thermoplastic resin may improve the peelability of the protective film from the support sheet, or make it easier for the protective film-forming film to conform to the uneven surface of the adherend.

[0073] The weight-average molecular weight of the thermoplastic resin is preferably 1,000 to 100,000, and more preferably 3,000 to 80,000.

[0074] The glass transition temperature (Tg) of the thermoplastic resin is preferably -30 to 150°C, and more preferably -20 to 120°C.

[0075] Examples of the thermoplastic resins include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

[0076] The thermoplastic resin contained in composition (III) 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.

[0077] In composition (III), the ratio of the content of polymer component (A) to the total content of all components other than the solvent is preferably 10 to 85% by mass, more preferably 15 to 70% by mass, regardless of the type of polymer component (A), and may be, for example, 15 to 45% by mass and 15 to 35% by mass, or 20 to 70% by mass and 25 to 70% by mass. This statement is equivalent to saying that, in a protective film-forming film, the ratio of the polymer component (A) content to the total mass of the protective film-forming film is preferably 10 to 85% by mass, more preferably 15 to 70% by mass, regardless of the type of polymer component (A), and may be, for example, 15 to 45% by mass and 15 to 35% by mass, or 20 to 70% by mass and 25 to 70% by mass. This is based on the fact that, in the process of removing the solvent from a solvent-containing resin composition to form a resin film, the amount of components other than the solvent usually does not change, and the ratio of the contents of non-solvent components is the same in the resin composition and the resin film. Therefore, in this specification, hereafter, not limited to the case of protective film-forming films, the content of non-solvent components will only be described in the resin film obtained by removing the solvent from the resin composition.

[0078] Polymer component (A) may also correspond to thermosetting component (B). In the present invention, if composition (III) contains components that correspond to both polymer component (A) and thermosetting component (B), composition (III) is deemed to contain polymer component (A) and thermosetting component (B).

[0079] [Thermosetting component (B)] Thermosetting component (B) is a component for curing the protective film. The thermosetting component (B) contained in composition (III) 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.

[0080] Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyimide resins, and unsaturated polyester resins, with epoxy-based thermosetting resins being preferred. In this specification, thermosetting polyimide resin is a general term encompassing a polyimide precursor and a thermosetting polyimide, both of which form a polyimide resin through thermosetting.

[0081] (Epoxy thermosetting resin) Epoxy thermosetting resins consist of an epoxy resin (B1) and a thermosetting agent (B2). The epoxy thermosetting resin contained in composition (III) 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.

[0082] • Epoxy resin (B1) Examples of epoxy resins (B1) 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.

[0083] As the epoxy resin (B1), an epoxy resin having unsaturated hydrocarbon groups may be used.

[0084] The number-average molecular weight of the epoxy resin (B1) 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 epoxy resin (B1) is preferably 100 to 1000 g / eq, and more preferably 150 to 950 g / eq.

[0085] Epoxy resin (B1) may be used alone or in combination of two or more types. When using two or more types in combination, the combination and ratio of these types can be arbitrarily selected.

[0086] • Thermosetting agent (B2) The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1). Examples of the thermosetting agent (B2) 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.

[0087] Examples of thermosetting agents (B2) 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 (B2) include dicyandiamide.

[0088] The thermosetting agent (B2) may have an unsaturated hydrocarbon group.

[0089] When a phenolic curing agent is used as the thermosetting agent (B2), it is preferable that the thermosetting agent (B2) has a high softening point or glass transition temperature, as this improves the peelability of the protective film from the support sheet.

[0090] Among the thermosetting agents (B2), 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 (B2), such as biphenol or dicyandiamide, is not particularly limited, but is preferably 60 to 500.

[0091] The thermosetting agent (B2) may be used alone or in combination of two or more types. When using two or more types in combination, the combination and ratio of these types can be arbitrarily selected.

[0092] The content of the thermosetting agent (B2) in the protective film is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, per 100 parts by mass of epoxy resin (B1), and may be, for example, 0.5 to 25 parts by mass, 0.5 to 10 parts by mass, or 0.5 to 5 parts by mass. When the content of the thermosetting agent (B2) is above the lower limit, the curing of the protective film proceeds more easily. When the content of the thermosetting agent (B2) 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 is further improved.

[0093] In the protective film, the content of the thermosetting component (B) (for example, the total content of epoxy resin (B1) and thermosetting agent (B2)) is preferably 10 to 100 parts by mass, more preferably 20 to 70 parts by mass, even more preferably 25 to 55 parts by mass, and particularly preferably 30 to 45 parts by mass, based on 100 parts by mass of the total content of polymer component (A) and thermosetting component (B). When the content of the thermosetting component (B) is above the lower limit, for example, the storage modulus E'(23) of the protective film after thermosetting is made easier to increase. When the content of the thermosetting component (B) is below the upper limit, for example, the storage modulus E'(90) is made easier to decrease.

[0094] [Filling material (D)] The composition (III) and the protective film-forming film preferably contain a filler (D). By including a filler (D) in the protective film-forming film, the storage modulus E' of the test specimen can be more easily adjusted. More specifically, by adjusting the average particle size of the filler (D) contained in the protective film-forming film and the amount of filler (D) in the protective film-forming film, the storage modulus E' of the test specimen can be more easily adjusted. Furthermore, by including a filler (D) in the protective film-forming film, the thermal expansion coefficient of the protective film-forming film and the protective film can be easily adjusted, and by optimizing this thermal expansion coefficient for the object on which the protective film is formed, the reliability of the protective film-coated chip obtained using the protective film-forming film can be further improved. In addition, by including a filler (D) in the protective film-forming film, the moisture absorption rate of the protective film can be reduced and the heat dissipation can be improved.

[0095] The filler (D) may be either an organic filler or an inorganic filler, but an inorganic filler is preferred. Preferred inorganic fillers include, for example, powders such as silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride; beads formed from these inorganic fillers in a spherical shape; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers. Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

[0096] In a protective film-forming composition, in terms of improving the dispersibility of the filler (D) with respect to other components, the silica is preferably silica surface-modified with organic groups, more preferably silica surface-modified with vinyl groups, epoxy groups, phenyl groups, or methacrylic groups, and particularly preferably silica surface-modified with vinyl groups or epoxy groups.

[0097] In a protective film-forming composition, the average particle size of the filler (D) is preferably 0.05 to 2 μm, more preferably 0.2 to 0.9 μm, and particularly preferably 0.4 to 0.7 μm, in order to improve the dispersibility of the filler (D) with respect to other components. When the average particle size of the filler (D) is above the lower limit, the storage modulus E'(90) and storage modulus E'(70) tend to be reduced.

[0098] In this specification, "average particle diameter" refers to the particle diameter at 50% of the integrated value in the particle size distribution curve obtained by laser diffraction scattering (D 50 This refers to the value of ).

[0099] The composition (III) and the filler (D) contained in 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.

[0100] When a filler (D) is used, the ratio of the content of the filler (D) to the total mass of the protective film forming film is preferably 30% by mass or more and 70% by mass or less. For example, it may be any of 35% by mass or more and 70% by mass or less, 35% by mass or more and 65% by mass or less, and 35% by mass or more and 59% by mass or less, or it may be 35% by mass or more and less than 50% by mass. Having the ratio in this range makes it easier to adjust the storage modulus E'(90), the storage modulus E'(70), and the storage modulus E'(23) of the protective film after heat curing to be within the above range. The ratio of the content of the filler (D) to the total mass of the protective film forming film is preferably 40% by mass or more and 70% by mass or less. For example, it may be any of 45% by mass or more and 70% by mass or less, 45% by mass or more and 65% by mass or less, and 45% by mass or more and 59% by mass or less, or it may be 45% by mass or more and less than 50% by mass.

[0101] [Curing accelerator (C)] Composition (III) and the protective film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of composition (III). Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organophosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

[0102] The curing accelerator (C) contained in composition (III) 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.

[0103] When a curing accelerator (C) is used, the content of the curing accelerator (C) in the protective film is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 7 parts by mass, per 100 parts by mass of the thermosetting component (B). When the content of the curing accelerator (C) is above the lower limit, the effect of using the curing accelerator (C) is more pronounced, and it becomes easier to increase the storage modulus E'(23) of the protective film after heat curing. When the content of the curing accelerator (C) is below the upper limit, for example, the effect of suppressing the migration and segregation of highly polar curing accelerators (C) to the adhesive interface side with the adherend in the protective film under high temperature and high humidity conditions is enhanced. As a result, the reliability of the protective film-coated chip obtained using the protective film-coating film is further improved.

[0104] [Coupling agent (E)] Composition (III) and the protective film-forming film may contain a coupling agent (E). By using a coupling agent (E) that has a functional group that can react with an inorganic compound or an organic compound, the adhesion of the protective film formed from the protective film-forming film to the adherend can be improved. Furthermore, by using a coupling agent (E), the water resistance of the protective film is improved without impairing its heat resistance.

[0105] The coupling agent (E) is preferably a compound having a functional group that can react with the functional groups of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent.

[0106] 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.

[0107] Preferred silane coupling agents include oligomeric silane coupling agents having multiple alkoxysilyl groups in one molecule. The oligomeric silane coupling agent is preferable because it is less volatile and has multiple alkoxysilyl groups in one molecule, making it effective in improving durability. Examples of the oligomeric silane coupling agents include the epoxy group-containing oligomeric silane coupling agents "X-41-1053", "X-41-1059A", "X-41-1056", and "X-40-2651" (all manufactured by Shin-Etsu Chemical Co., Ltd.); and the mercapto group-containing oligomeric silane coupling agents "X-41-1818", "X-41-1810", and "X-41-1805" (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0108] The coupling agent (E) contained in composition (III) 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.

[0109] When a coupling agent (E) is used, the content of the coupling agent (E) in the protective film is preferably 0.03 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and particularly preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the total content of the polymer component (A) and the thermosetting component (B). When the content of the coupling agent (E) is above the lower limit, the effects of using the coupling agent (E), such as improved dispersibility of the filler (D) in the resin and improved adhesion of the protective film to the adherend, are more pronounced. When the content of the coupling agent (E) is below the upper limit, outgassing is further suppressed.

[0110] [Crosslinking agent (F)] When polymer component (A) is a polymer having functional groups such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups that can bond with other compounds, such as the acrylic resin mentioned above, composition (III) 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 polymer component (A) with other compounds, and by crosslinking in this way, the adhesive strength and cohesive strength of the protective film-forming film can be adjusted.

[0111] 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).

[0112] The crosslinking agent (F) contained in composition (III) 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] In terms of reducing the storage modulus E'(90) and the storage modulus E'(70), it is preferable that composition (III) does not contain a crosslinking agent (F), or that the content of the crosslinking agent (F) in composition (III) is small, for example, less than 0.01 parts by mass per 100 parts by mass of polymer component (A). In contrast, when using a certain amount or more of crosslinking agent (F), the content of crosslinking agent (F) in composition (III) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass, based on the content of polymer component (A) per 100 parts by mass. When the content of crosslinking agent (F) is above the lower limit, the effect of using crosslinking agent (F) is obtained more significantly. When the content of crosslinking agent (F) is below the upper limit, it becomes easier to make the storage modulus E'(90) and the storage modulus E'(70) smaller.

[0114] [Energy ray curable resin (G)] Composition (III) and the protective film may contain an energy-curable resin (G). The protective film contains an energy-curable resin (G), which allows its properties to be altered by irradiation with energy rays.

[0115] The energy-ray curable resin (G) is an energy-ray curable compound, or an oligomer or polymer (polymer) that can be considered to be synthesized from an energy-ray curable compound. Examples of the energy ray curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

[0116] Examples of the aforementioned acrylate compounds include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and other chains. Examples include cyclic aliphatic skeleton-containing (meth)acrylates; cyclic aliphatic skeleton-containing (meth)acrylates such as dicyclopentanyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates; urethane (meth)acrylate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the aforementioned polyalkylene glycol (meth)acrylates; and itaconic acid oligomers.

[0117] The weight-average molecular weight of the energy-ray curable compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

[0118] The energy-curable compound used in the synthesis of the oligomer or polymer 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.

[0119] The energy-curable resin (G) contained in composition (III) 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.

[0120] When using an energy-ray curable resin (G), the ratio of the content of the energy-ray curable resin (G) to the total mass of composition (III) is preferably 1 to 30% by mass, more preferably 5 to 25% by mass, and particularly preferably 10 to 20% by mass.

[0121] [Photopolymerization initiator (H)] If composition (III) and the protective film-forming film contain an energy-ray curable resin (G), they may also contain a photopolymerization initiator (H) to efficiently advance the polymerization reaction of the energy-ray curable resin (G).

[0122] Examples of photopolymerization initiators (H) in composition (III) 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)phenyl Examples include acylphosphine oxide compounds such as phosphine oxide and 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 (H) include photosensitizers such as amines.

[0123] The photopolymerization initiator (H) contained in composition (III) 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.

[0124] When a photopolymerization initiator (H) is used, the content of the photopolymerization initiator (H) in composition (III) 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 resin (G).

[0125] [Coloring agent (I)] The composition (III) and the protective film preferably contain a colorant (I). By including a colorant (I), the light transmittance of the protective film and the protective film can be easily adjusted.

[0126] Examples of colorants (I) include known ones such as inorganic pigments, organic pigments, and organic dyes.

[0127] 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.

[0128] 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.

[0129] The colorants (I) contained in composition (III) 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.

[0130] When using a coloring agent (I), the content of the coloring agent (I) in the protective film-forming film can be appropriately adjusted according to the purpose. For example, by adjusting the content of the coloring agent (I) in the protective film-forming film and thereby adjusting the light transmittance of the protective film-forming film, the visibility of the printed markings when laser printing is performed on the protective film-forming film or protective film can be adjusted. Furthermore, by adjusting the content of the coloring agent (I) in the protective film-forming film, it is possible to improve the aesthetic appearance of the protective film or make grinding marks on the back surface of the wafer less visible. Considering these points, the ratio of the content of the coloring agent (I) to the total mass of the protective film-forming film is preferably 0.1 to 10% by mass, more preferably 0.1 to 7.5% by mass, and particularly preferably 0.1 to 5% by mass. When the ratio is above the lower limit, the effect of using the coloring agent (I) is more pronounced. For example, when the protective film-forming film is peeled off from the adherend, it is easy to visually confirm whether or not any residue of the protective film-forming film remains on the adherend. By keeping the aforementioned ratio below the aforementioned upper limit, excessive use of coloring agent (I) is suppressed.

[0131] [General-purpose additive (J)] Composition (III) and the protective film-forming film may contain a general-purpose additive (J) within a range that does not impair the effects of the present invention. The general-purpose additive (J) may be any known additive and can be arbitrarily selected according to the purpose, and is not particularly limited, but preferred examples include plasticizers, antistatic agents, antioxidants, gettering agents, and ultraviolet absorbers.

[0132] The general-purpose additive (J) contained in composition (III) 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. The content of composition (III) and the general-purpose additive (J) in the protective film-forming film is not particularly limited and may be appropriately selected depending on the purpose.

[0133] [solvent] Composition (III) preferably further contains a solvent. Composition (III) containing a solvent has good handling properties. In this specification, unless otherwise specified, the term "solvent" includes not only substances that dissolve the target component but also dispersion media that disperse the target component.

[0134] 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 (III) 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.

[0135] More preferred solvents for composition (III) include, for example, methyl ethyl ketone, toluene, and ethyl acetate, as they allow for more uniform mixing of the components in composition (III).

[0136] The solvent content of composition (III) is not particularly limited and may be appropriately selected depending on the type of components other than the solvent.

[0137] <Method for producing protective film-forming composition (III)> Composition (III) is obtained by blending the components that constitute it. 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.

[0138] ◎Examples of protective film-forming films 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.

[0139] 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.

[0140] When the storage modulus E' of the test specimen prepared using the protective film-forming film 13 is measured, the storage modulus E'(90) of the test specimen at 90°C is 5 MPa or less.

[0141] The protective film-forming film 13 can be formed using the protective film-forming composition described above.

[0142] The first release film 151 and the second release film 152 may both be known types. 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.

[0143] In Figure 1, the protective film-forming film 13 is formed when either the first release film 151 or the second release film 152 is removed, and the resulting exposed surface becomes the surface to be attached to any part of the workpiece (not shown). When a support sheet or dicing sheet, which will be described later, is used, the remaining part of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface of the protective film-forming film 13 becomes the surface to be attached to the support sheet or dicing sheet.

[0144] 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.

[0145] The protective film-forming film of this embodiment, when used in combination with a support sheet described later, can form a composite sheet for forming a protective film that can perform both protective film formation and workpiece processing (e.g., dicing) simultaneously. Such a composite sheet for forming a protective film will be described below.

[0146] ◇ 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 can be attached to a target location on a workpiece (for example, the back surface of a wafer) by the protective film-forming film contained within it.

[0147] In this specification, as long as the laminated structure of the support sheet and the thermoset product of the protective film-forming film is maintained even after the protective film-forming film has hardened, this laminated structure will be referred to as a "composite sheet for forming a protective film."

[0148] The following describes in detail each layer that constitutes the composite sheet for forming the protective film.

[0149] ◎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.

[0150] The support sheet may be transparent or opaque, and may be colored depending on the purpose. If the protective film is energy ray curable, the support sheet is preferably one that transmits energy rays.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] ◎ An example of a composite sheet for forming a protective film. 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.

[0155] 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).

[0156] 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).

[0157] 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 2) can be of any configuration, and the protective film-forming composite sheet of this embodiment may or may not include a release film.

[0158] 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 jig adhesive layer 16 may, for example, have a single-layer structure containing an adhesive component or a tack component, or it may have a multi-layer structure comprising a core sheet and layers containing an adhesive component or a tack component provided on both sides of the sheet.

[0159] The protective film-forming composite sheet 101 is used when the release film 15 is removed, the desired portion of the workpiece is attached to the first surface 13a of the protective film-forming film 13, and the first surface 16a of the jig adhesive layer 16 is attached to a jig such as a ring frame.

[0160] As described above, even if scratches are formed on the surface of the thermosetting protective film-forming film during the process of manufacturing the protective film-forming workpiece or the workpiece processed product with the protective film using the protective film-forming composite sheet 101 equipped with the protective film-forming film 13, the scratches on the surface of the protective film after the protective film-forming film 13 has been heat-cured can be made less noticeable.

[0161] Figure 3 is a schematic cross-sectional view showing another example of the composite sheet for forming a protective film according to 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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 13 (one side) 20a is the same as the first side 11a of the base material 11.

[0166] The composite sheet for forming the protective film in this embodiment is not limited to those shown in Figures 1 to 5. Within the limits that do not impair the effects of the present invention, some components of those shown in Figures 1 to 5 may be modified or deleted, or other components may be added to those described herein.

[0167] Next, we will describe each layer that makes up the support sheet in more detail.

[0168] ○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. The aforementioned resin is preferably polypropylene or polybutylene terephthalate, as it offers excellent heat resistance.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] The substrate may be transparent or opaque, and may be colored or have other layers deposited on it, depending on the purpose. If the protective film forming the film has energy ray curability, the substrate is preferably one that transmits energy rays.

[0174] 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.

[0175] The base material may contain components within a specific range (e.g., resin, etc.) to have adhesive properties on at least one surface.

[0176] 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.

[0177] ○ 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.

[0178] 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.

[0179] The thickness of the adhesive layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 1 to 60 μm, and particularly 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.

[0180] The adhesive layer may be transparent or opaque, and may be colored depending on the purpose. If the protective film is energy ray curable, the adhesive layer is preferably one that allows energy rays to pass through.

[0181] 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, by curing the energy-ray curable adhesive layer before picking up the protective film-coated chip (described later), the protective film-coated chip can be picked up more easily.

[0182] 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 "support sheet".

[0183] 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.

[0184] 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.

[0185] 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.

[0186] 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).

[0187] [Non-energy ray curable adhesive resin (I-1a)] The adhesive resin (I-1a) is preferably an acrylic resin.

[0188] 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.

[0189] 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 form a starting point for crosslinking.

[0190] 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.

[0191] The acrylic polymer may have, in addition to structural units derived from alkyl (meth)acrylate and structural units derived from functional group-containing monomers, structural units derived from other 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 the other monomers mentioned above include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] [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.

[0197] 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.

[0198] Examples of the unsaturated group-containing compounds include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

[0199] 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.

[0200] 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.

[0201] [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.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] [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.

[0206] 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).

[0207] 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.

[0208] 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). 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).

[0209] [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.

[0210] Examples of the photopolymerization initiator include those similar to the photopolymerization initiator (H) described above.

[0211] 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.

[0212] In the 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 the 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.

[0213] [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. Other known additives include, for example, antistatic agents, antioxidants, plasticizers, fillers, rust inhibitors, colorants (pigments, dyes), sensitizers, tackifiers, reaction retarders, and crosslinking accelerators (catalysts). A reaction retarder is, for example, a component that suppresses the unintended crosslinking reaction that occurs in adhesive compositions (I-1) to (I-4) during storage due to the action of a catalyst mixed in them. Examples of reaction retarders include those that form a chelate complex by chelation with the catalyst, and more specifically, those that have two or more carbonyl groups (-C(=O)-) in one molecule.

[0214] The other additives 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.

[0215] The content of other additives in adhesive compositions (I-1) to (I-4) is not particularly limited and may be appropriately selected depending on their type.

[0216] [solvent] Adhesive compositions (I-1) to (I-4) may contain a solvent. The presence of a solvent in adhesive compositions (I-1) to (I-4) improves their applicability to the surface to be coated.

[0217] The solvent is preferably an organic solvent. Examples of organic solvents include ketones such as methyl ethyl ketone and acetone; esters (carboxylic acid esters) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; and alcohols such as 1-propanol and 2-propanol.

[0218] 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.

[0219] The solvent content of adhesive compositions (I-1) to (I-4) is not particularly limited and may be adjusted as appropriate.

[0220] ○ Method for manufacturing adhesive compositions 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.

[0221] ◇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.

[0222] 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. Furthermore, the release film in this case can be removed at either the manufacturing or usage stage of the protective film-forming composite sheet. Up to this point, we have used the example of laminating an adhesive layer on a substrate, but the above method can also be applied to cases where other layers besides the adhesive layer are laminated on the substrate.

[0223] 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.

[0224] 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.

[0225] 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 opposite to the side of this layer that is in contact with the release film, and the release film is not removed, resulting in a composite sheet for forming a protective film with a release film.

[0226] ◇Method for manufacturing a workpiece with a protective film (Method for using protective film-forming film and composite sheet for protective film formation) The protective film forming film and the protective film forming composite sheet can be used in the manufacture of a protective film-covered workpiece, which comprises a workpiece and a protective film provided on any part of the workpiece.

[0227] The method for manufacturing a workpiece with a protective film according to this embodiment includes an attachment step of attaching a protective film-forming film that does not constitute the protective film-forming composite sheet, or a protective film-forming film within the protective film-forming composite sheet, to a target location on the workpiece, thereby producing a workpiece with a protective film-forming film comprising the workpiece and the protective film-forming film; The process includes a heat curing step, after the bonding step, in which the protective film-forming film is heat-cured to form the protective film, thereby producing a workpiece with the protective film. When the workpiece is a wafer, the workpiece with a protective film includes a wafer and a protective film provided on the back surface of the wafer. The method for manufacturing the wafer with the protective film includes an attachment step of attaching a protective film-forming film that does not constitute the protective film-forming composite sheet, or a protective film-forming film within the protective film-forming composite sheet, to the back surface of the wafer, thereby producing a workpiece with a protective film-forming film comprising the wafer and the protective film-forming film provided on the back surface of the wafer; The process includes a heat curing step, after the bonding step, in which the protective film-forming film is heat-cured to form the protective film, thereby producing a workpiece with the protective film.

[0228] <<Manufacturing method for wafers with protective film (Manufacturing method (1-1))>> The following explanation will use the method of manufacturing a wafer with a protective film as an example of a method for manufacturing a workpiece with a protective film, and will refer to the drawings.

[0229] Figure 6 is a schematic cross-sectional view illustrating an example of a manufacturing method for a wafer with a protective film according to this embodiment, specifically when a protective film-forming film is used (sometimes referred to as "Manufacturing Method (1-1)" in this specification). Here, we will describe the case using the protective film-forming film 13 shown in Figure 1.

[0230] In the pasting step of the manufacturing method (1-1), first, as shown in Fig. 6(a), the first release film 151 is removed, and a protective film forming film 13 having a second release film 152 on one surface (here, the second surface 13b) and the other surface (here, the first surface 13a) exposed is used. By pasting the first surface 13a to the back surface 9b of the wafer 9, as shown in Fig. 6(c), a wafer 901 with a protective film forming film is produced.

[0231] The arrow in Fig. 6(a) indicates the pasting direction of the protective film forming film 13 onto the wafer 9. At this time, the wafer 9 is placed on a table 8 that can adjust its own temperature, for example, as shown here. By heating the table 8, the wafer 9 is heated, and it is preferable to paste the protective film forming film 13 onto the heated wafer 9. In order to paste the protective film forming film 13 on the back surface 9b of the wafer 9, the wafer 9 is placed on the table 8 with the circuit surface 9a side having the protruding electrode 90 facing the table 8. Here, the illustration of the circuit of the wafer 9 is omitted.

[0232] When pasting the protective film forming film 13 on the back surface of the wafer 9, it is pressed with pressing means such as a laminating roll 16 through the second release film 152 from the side opposite to the wafer 9 side of the protective film forming film 13.

[0233] The pasting conditions of the protective film forming film 13 onto the wafer 9 are not particularly limited. Usually, the temperature of the protective film forming film 13 at the time of pasting (pasting temperature) is preferably 20 to 100°C, the pasting speed of the protective film forming film is preferably 0.1 to 2 m / min, and the pressure applied to the protective film forming film 13 at the time of pasting (pasting pressure) is preferably 0.1 to 0.6 MPa.

[0234] As shown in Figures 6(b) and 6(c), the second release film 152 is removed from the protective film forming film 13 after it has been attached to the wafer 9. For example, when pressing the protective film forming film 13 with a laminating roll 16 from the side opposite to the wafer 9 side via the second release film 152, particulate foreign matter 17 may get mixed between the second release film 152 and the laminating roll 16, and indentation marks 18 of the particulate foreign matter 17 may be formed on the surface 13b of the protective film forming film 13 opposite to the wafer 9 side.

[0235] In the manufacturing method (1-1), after the bonding step, the heat curing step involves heat curing the protective film-forming film 13 that has been bonded to the wafer 9 to form a protective film 13', thereby producing a wafer 902 with a protective film, as shown in Figure 6(d).

[0236] The heating conditions for the protective film-forming film in the thermosetting process are not particularly limited, as long as the protective film-forming film is thermoset to form a protective film and hardened to a degree sufficient for the protective film to fully perform its function. The heating temperature for the protective film-forming film in the thermosetting process is preferably 100 to 180°C, more preferably 110 to 160°C, and particularly preferably 120 to 140°C. The heating time for the protective film-forming film in the thermosetting process is preferably 0.5 to 5 hours, more preferably 0.5 to 4 hours, and particularly preferably 1 to 3 hours.

[0237] When using a conventional protective film, if the indentation mark 18 is formed on the surface 13b of the protective film 13 opposite to the wafer 9 side, the indentation mark 18 will remain even after the heat curing process, resulting in the production of defective products. In contrast, in the manufacturing method (1-1) using the protective film forming film of this embodiment, even if scratches such as indentations 18 are formed on the surface of the protective film forming film 13, the scratches can be reduced in size by the self-healing effect of heating through the heat curing process, making the scratches on the surface of the protective film 13' less noticeable.

[0238] The manufacturing method (1-1) preferably includes a heating step after the bonding step and before the heat curing step in which the protective film forming film 13 is heated under conditions that prevent the protective film forming film 13 from heat curing. By heating the protective film forming film 13 under conditions that prevent the protective film forming film 13 from heat curing, scratches on the surface of the protective film forming film 13 can be reduced, and scratches on the surface of the protective film 13' can be made less noticeable.

[0239] The heating conditions for the protective film-forming film in the heating process are not particularly limited, as long as the protective film-forming film 13 is not heat-cured and the surface scratches of the protective film-forming film 13 can be minimized. The heating temperature for the protective film-forming film in the heating process is preferably 75 to 105°C, more preferably 80 to 100°C, and particularly preferably 85 to 95°C. The heating time for the protective film-forming film in the heating process is preferably 0.5 to 5 hours, more preferably 0.5 to 4 hours, and particularly preferably 1 to 3 hours.

[0240] Using the protective film-coated wafer 902 obtained above, a protective film-coated chip (not shown) can be manufactured by dividing the wafer 9 and cutting the protective film 13'.

[0241] Up to this point, we have described a method for manufacturing wafers with a protective film using a protective film-forming film as the manufacturing method (1-1). However, wafers with a protective film can also be manufactured by using a composite sheet for protective film formation that incorporates a protective film-forming film instead of the protective film-forming film.

[0242] <<Manufacturing method for wafers with protective film (Manufacturing method (1-2))>> Figure 7 is a schematic cross-sectional view illustrating an example of a manufacturing method for a wafer with a protective film according to this embodiment, which uses a protective film-forming film that does not constitute a composite sheet for forming the protective film, and further includes a transport step (sometimes referred to as "Manufacturing Method (1-2)" in this specification). Here, we will explain the case using the protective film-forming film 13 shown in Figure 1.

[0243] The bonding step in manufacturing method (1-2) can be carried out in the same way as the bonding step in manufacturing method (1-1), such as by using a laminating roll. A wafer 901 with a protective film is produced by the bonding step of the manufacturing method (1-2) described above, as shown in Figure 7(a). In Figure 7(a), as in Figure 6(c), scratches such as indentation marks 18 (not shown) may be formed on the surface 13b of the protective film-forming film 13 opposite to the wafer 9 side.

[0244] In the transport process described above, as shown in Figure 7(b), the transport means 7 used to transport the wafer 901 with the protective film is brought into contact with the exposed surface (in this case, the second surface 13b) of the protective film forming film 13 in the wafer 901 with the protective film forming film, and the wafer 901 with the protective film forming film is fixed by the transport means 7. The transport means 7 may be any known means, for example, a means for fixing the object to be transported (in this case, a wafer 901 with a protective film) by suction at the contact point with the object (for example, a so-called suction arm) can be used as the transport means 7. In this case, the contact point may be a suction cup. However, the transport means 7 is not limited to this, and the object to be transported may be fixed by means other than suction. Note that the cross-sectional view of the transport mechanism 7 is omitted here.

[0245] In the aforementioned transport process, the wafer 901 with the protective film attached, which is fixed by the transport means 7, is then pulled away from the table 8, as shown in Figure 7(c). The arrows in Figure 7(c) indicate the direction in which the wafer 901 with the protective film attached is pulled away from the table 8.

[0246] Then, as it is, as shown in FIG. 7(d), the wafer 901 with the protective film forming film is transported in a fixed state by the transport means 7. In FIG. 7(d), the transport direction of the wafer 901 with the protective film forming film is indicated by an arrow, but this is an example of the transport direction, and the transport direction is not limited to this direction only.

[0247] In the above transport process, next, as shown in FIG. 7(e), in the wafer 901 with the protective film forming film after being transported to the target location, the fixed state by the transport means 7 is released, and the transport means 7 is separated from the wafer 901 with the protective film forming film. Thus, the above transport process ends.

[0248] After the transport process, in the protective film forming film 13 in the wafer 901 with the protective film forming film, more specifically, in the contact part of the fixed part in the transport means 7 on the second surface 13b of the protective film forming film 13, contact marks 19 caused by the contact of the transport means 7 may be formed. For example, when the fixed part is a suction plate with a circular planar shape, circular contact marks 19 may be formed on the exposed surface of the protective film forming film 13.

[0249] After the transport process of the manufacturing method (1-2), in the heat curing process, the protective film forming film 13 after being attached to the wafer 9 is heat cured to form a protective film 13', thereby producing a wafer 902 with a protective film as shown in FIG. 7(f). The heat curing process of the manufacturing method (1-2) can be performed in the same manner as the heat curing process of the manufacturing method (1-1).

[0250] When a conventional protective film forming film is used, if scratch marks such as pressing marks 18 and contact marks 19 are formed on the surface 13b on the side opposite to the wafer 9 side of the protective film forming film 13, the scratch marks will remain even after the heat curing process, resulting in defective products. In contrast, in the manufacturing method (1-2) using the protective film forming film of this embodiment, even if scratches are formed on the surface of the protective film forming film 13, the scratches can be reduced in size by performing a heat curing process due to the self-healing effect of heating, making the scratches on the surface of the protective film 13' less noticeable.

[0251] The manufacturing method (1-2) preferably includes a heating step after the conveying step and before the heat curing step in which the protective film forming film 13 is heated under conditions that prevent the protective film forming film 13 from heat curing. By heating the protective film forming film 13 under conditions that prevent the protective film forming film 13 from heat curing, the scratches on the surface of the protective film forming film 13 can be reduced, and the scratches on the surface of the protective film 13' can be made less noticeable. The heating step in manufacturing method (1-2) can be carried out in the same manner as the heating step in manufacturing method (1-1).

[0252] Using the protective film-coated wafer 902 obtained above, a protective film-coated chip (not shown) can be manufactured by dividing the wafer 9 and cutting the protective film 13'.

[0253] <<Variable Method of Manufacturing a Workpiece with Protective Film>> The method for manufacturing a workpiece with a protective film according to this embodiment may include other steps that do not fall under any of the above-mentioned application step, conveying step, heating step, or thermosetting step, as long as they do not impair the effects of the present invention. The aforementioned other steps can be arbitrarily selected depending on the purpose and are not particularly limited. The timing for performing the other processes can be appropriately selected depending on the content of those other processes.

[0254] As an example of the other steps in the method for manufacturing the wafer with the protective film, if the wafer has a backgrind tape on its circuit surface, a backgrind tape removal step is taken to remove the backgrind tape from the circuit surface of the wafer before the bonding step. The backgrind tape may be a known type, and the backgrind tape can be attached to the circuit surface of the wafer and removed from the circuit surface of the wafer by known methods.

[0255] Up to this point, the manufacturing methods (1-1) and (1-2) have been described in the case where the protective film-forming film 13 shown in Figure 1 is used. However, in the manufacturing method of the protective film-coated workpiece of this embodiment, a protective film-forming composite sheet may be used, including the protective film-forming composite sheet 101 shown in Figure 2, the protective film-forming composite sheet 102 shown in Figure 3, the protective film-forming composite sheet 103 shown in Figure 4, the protective film-forming composite sheet 104 shown in Figure 5, and the like. When using the aforementioned composite sheet for forming a protective film, the method for manufacturing a workpiece with a protective film according to this embodiment may include the aforementioned other steps performed at any given time, based on the differences in the configuration of the composite sheet for forming a protective film and the protective film forming film 13 shown in Figure 1.

[0256] ◇Method for manufacturing workpieces with protective coatings (Method for using protective coating-forming films and composite sheets for protective coating formation) The protective film forming film and the protective film forming composite sheet can be used to manufacture a workpiece with a protective film, which comprises a workpiece obtained by processing a workpiece and a protective film provided on any part of the workpiece. The method for manufacturing a workpiece with a protective film according to this embodiment differs from the method for manufacturing a workpiece with a protective film described above in that it includes a step of manufacturing a workpiece by processing the workpiece.

[0257] The method for manufacturing a workpiece with a protective film according to this embodiment includes: an attachment step of manufacturing a workpiece with a protective film, comprising the workpiece and the protective film, by attaching the protective film forming film, which is not part of the protective film forming composite sheet, or the protective film forming film in the protective film forming composite sheet, to a target location on the workpiece; a processing step of manufacturing the workpiece by processing the workpiece after the attachment step; and a heat curing step of forming the protective film by heat curing the protective film after the attachment step. When the workpiece is a wafer, the workpiece with the protective film includes a chip and a protective film provided on the back surface of the chip. The method for manufacturing the chip with a protective film comprises: an attachment step of producing a wafer with a protective film, comprising the wafer and the protective film provided on the back surface of the wafer, by attaching a protective film forming film that does not constitute the protective film forming composite sheet, or a protective film forming film within the protective film forming composite sheet, to the back surface of the wafer; a processing step (which can also be called a "dividing step") of producing a chip by dividing the wafer after the attachment step; and a heat curing step of forming the protective film by heat curing the protective film forming film after the attachment step.

[0258] <<Manufacturing method for chips with protective film (Manufacturing method (2-1))>> The following explanation will use the method of manufacturing a chip with a protective coating as an example of a method for manufacturing a workpiece with a protective coating, and will refer to the drawings. Figure 8 is a schematic cross-sectional view illustrating an example of a manufacturing method for a chip with a protective film according to this embodiment, in which a protective film-forming film that does not constitute a composite sheet for forming the protective film is used (this may be referred to as "manufacturing method (2-1)" in this specification). Here, we will explain the case in which the protective film-forming film 13 shown in Figure 1 is used.

[0259] In the bonding step of the manufacturing method (2-1) described above, as shown in Figure 8(a), the surface 13a of the protective film forming film 13 from which the first release film 151 has been removed is bonded to the back surface 9b of the wafer 9 to produce a wafer 901 with a protective film forming film.

[0260] The bonding step in manufacturing method (2-1) can be carried out in the same way as the bonding step in manufacturing method (1-1), such as by using a laminating roll. In the bonding step of manufacturing method (2-1), as in the bonding step of manufacturing method (1-1), scratches such as indentation marks 18 (not shown) may be formed on the surface 13b of the protective film forming film 13 opposite to the wafer 9 side.

[0261] After the bonding step of the manufacturing method (2-1) and before the processing step, as shown in Figure 8(b), the second release film 152 is removed from the wafer 901 with the protective film forming film, and the dicing sheet 80 is attached to the newly exposed surface, i.e., the second surface 13b of the protective film forming film 13. The dicing sheet 80 comprises a base material 81 and an adhesive layer 82 provided on one side thereof. In this step, the side of the adhesive layer 82 opposite to the base material 81 side (sometimes referred to as the "first surface" in this specification) 82a is attached to the second surface 13b of the protective film forming film 13. The first surface 82a of the adhesive layer 82 is the same as the first surface 80a of the dicing sheet 80. Thus, the manufacturing method (2-1) includes a dicing sheet attachment step between the attachment step and the processing step, in which a dicing sheet is attached to the side of the protective film-forming film in the wafer with the protective film-forming film that is opposite to the wafer side.

[0262] The dicing sheet 80 may have a similar configuration to the support sheet 10 in the protective film-forming composite sheet 101. Here, the case using dicing sheet 80 is shown, but in the manufacturing method (2-1), other known dicing sheets besides dicing sheet 80 may be used, such as a dicing sheet made only of a base material.

[0263] The dicing sheet 80 can be attached to the protective film forming film 13 by a known method, for example, by the same method as when the protective film forming film 13 is attached to the wafer 9 in the attachment step of the manufacturing method (1-1).

[0264] When the dicing sheet 80 is attached to the surface 13b of the protective film forming film 13, particulate foreign matter 17 may get mixed in between the dicing sheet 80 and the laminating roll 16, for example, and scratches such as indentation marks 18 (not shown) may be formed on the surface 13b of the protective film forming film 13 on the side opposite to the wafer 9.

[0265] In the manufacturing method (2-1), after the bonding step, the chip 90 is produced in the processing step by dividing the wafer 9. Furthermore, after the application process, the protective film-forming film 13 is cut during the cutting process. By performing the processing and cutting steps described above, a protective film-forming chip 913 is produced, as shown in Figure 8(c), which comprises a chip 90 and a protective film-forming film 130 provided on its back surface 90b after cutting. At the same time, a group of protective film-forming chips 903 is produced, which consists of multiple protective film-forming chips 913 held in an aligned state on a support sheet 10. In Figure 8(c), reference numeral 130a indicates the first surface of the protective film-forming film 130 after cutting, and corresponds to the first surface 13a of the protective film-forming film 13. Reference numeral 130b indicates the second surface of the protective film-forming film 130 after cutting, and corresponds to the second surface 13b of the protective film-forming film 13.

[0266] In the manufacturing method (2-1), it is preferable to perform the processing step and the cutting step simultaneously after the pasting step, or to perform the processing step first and then the cutting step. In the manufacturing method (2-1), if the wafer processing (splitting) and the cutting of the protective film-forming film are performed continuously using the same operation without interruption, regardless of the order, the processing step and the cutting step shall be considered to have been performed simultaneously.

[0267] Both the processing step and the cutting step can be carried out by known methods, depending on the order in which they are performed.

[0268] For example, when the processing and cutting processes are performed simultaneously, the wafer 9 can be divided and the protective film 13 cut at the same time by various dicing methods such as blade dicing using a blade, laser dicing using laser irradiation, or water dicing by spraying water containing an abrasive. Furthermore, by performing a so-called expansion, which involves pulling both the wafer 9 (which has a modified layer formed by stealth dicing and has not been divided) and the protective film-forming film 13 in a direction parallel to their surfaces, the wafer 9 can be divided and the protective film-forming film 13 can be cut simultaneously. Such expansion is preferably performed at low temperatures such as -20 to 5°C.

[0269] Stealth dicing (registered trademark) is a method that works as follows: First, a section to be divided is set inside the wafer, and a laser beam is shone onto this section, focusing the beam to form a modified layer inside the wafer. Unlike other parts of the wafer, the modified layer is altered by the laser beam and has weakened strength. Therefore, when force is applied to the wafer, cracks extending in both directions of the wafer are generated in the modified layer inside the wafer, becoming the starting point for wafer division. Next, force is applied to the wafer to divide it at the modified layer, and chips are produced.

[0270] For example, in the manufacturing method (2-1), by performing the processing step and cutting step, a chip 913 with a protective film is produced as shown in Figure 8(c), and a group of chips 903 with a protective film is produced, which consists of multiple such chips 913 with protective films held in an aligned state on a dicing sheet 80.

[0271] After the processing and cutting steps of the manufacturing method (2-1), the heat curing step is performed to produce protective film-coated chips 913' as shown in Figure 8(d), and a group of protective film-coated chips 904 is produced, which consists of multiple protective film-coated chips 913' held in an aligned state on the dicing sheet 80.

[0272] In Figure 8(d), reference numeral 130a' indicates the first surface of the protective film 130' and corresponds to the first surface 130a of the protective film-forming film 130 after cutting. Reference numeral 130b' indicates the second surface of the protective film 130' and corresponds to the second surface 130b of the protective film-forming film 130 after cutting.

[0273] The thermosetting step in manufacturing method (2-1) can be carried out in the same manner as the thermosetting step in manufacturing method (1-1).

[0274] In the case of manufacturing method (2-1), since the protective film forming film of the embodiment described above is used, similar to the case of manufacturing method (1-1), even if scratches such as indentation marks 18 are formed on the surface of the protective film forming film 13, the scratches can be reduced in size by performing a heat curing process due to the self-healing effect of heating, making the scratches on the surface of the protective film 13' less noticeable.

[0275] The manufacturing method (2-1) preferably includes a heating step of heating the protective film-forming film 130 under conditions that prevent the protective film-forming film 130 from heat-curing, either after the bonding step and before the processing step, or after the processing step and before the heat-curing step. By heating the protective film-forming film 130 under conditions that prevent the protective film-forming film 130 from heat-curing, the surface scratches of the protective film-forming film 130 can be reduced, and the surface scratches of the protective film 130' can be made less noticeable. The heating step in manufacturing method (2-1) can be carried out in the same manner as the heating step in manufacturing method (1-1).

[0276] In the heating step and the thermosetting step, the chip group 903 with the protective film-forming film can be arranged (so-called "horizontally") such that its surface (for example, the first surface 130a of the protective film-forming film 130 after cutting, and the back surface 90b of the chip 90) is parallel to the horizontal direction, thereby allowing the protective film-forming film 130 to be heated and thermoset. On the other hand, in the heating step and the heat curing step, the chip group 903 with the protective film-forming film may be arranged (so-called "vertical orientation") such that its surface (the same as above) is perpendicular to the horizontal direction (in other words, parallel to the vertical direction), and the protective film-forming film 130 may be heated or heat cured. When the chip group 902 with the protective film-forming film is heated in this vertical orientation, the occurrence of sagging in the region of the dicing sheet 80 that holds the chips 913' with the protective film can be suppressed more effectively than when it is heated in a horizontal orientation.

[0277] After the heat curing step in manufacturing method (2-1), as shown in Figure 8(e), a pickup step is performed in which the protective-coated chips 913' in the protective-coated chip group 904 are pulled away from the dicing sheet 80 to pick them up, thereby allowing the desired protective-coated chips 913' to be extracted. In the pickup step of the manufacturing method (2-1), delamination occurs between the second surface 130b' of the protective film 130' in the protective film-coated chip 913' and the first surface 82a of the adhesive layer 82 in the dicing sheet 80.

[0278] The protective film-covered chip 913' can be picked up by known methods. The protective film-coated tip 913' can be picked up using a push-up mechanism such as a push-up needle pin. Here, the case where the protective film-coated tip 913' is pulled away in the direction of arrow P using a separation mechanism 8 such as a vacuum collet is shown. Note that only the cross-sectional view of the separation means 8 is omitted here.

[0279] <<Manufacturing method for chips with protective film (Manufacturing method (2-2))>> Figure 9 is a schematic cross-sectional view illustrating an example of a manufacturing method for a chip with a protective film according to this embodiment, using a protective film-forming film in a composite sheet for forming a protective film (sometimes referred to as "Manufacturing Method (2-2)" in this specification). Here, we will describe the case using the composite sheet 101 for forming a protective film shown in Figure 2.

[0280] In the bonding step of the manufacturing method (2-2) described above, as shown in Figure 9(a), a wafer 901 with a protective film is produced by bonding the protective film forming film 13 from the protective film forming composite sheet 101, more specifically, the protective film forming film 13 from which the release film 15 has been removed, to the back surface 9b of the wafer 9.

[0281] In manufacturing method (2-2), the processing and cutting steps can be carried out in the same manner as in manufacturing method (2-1), except that, after the bonding step, a wafer 901 with a protective film that has a support sheet 10 is used instead of the wafer 901 with a protective film that has a dicing sheet 80 as described above, and a pick-up step is performed before the heat curing step.

[0282] For example, in the manufacturing method (2-2), by performing the processing step and cutting step, a chip 913 with a protective film is produced as shown in Figure 9(b), and a group of chips 905 with a protective film is produced, which consists of multiple such chips 913 with protective films held in an aligned state on a support sheet 10. The chip group 905 with protective film is the same as the chip group 903 with protective film in the manufacturing method (2-1), except that it is equipped with a support sheet 10 instead of a dicing sheet 80. The method for dividing the wafer 9 may be the same as, for example, the method for dividing the wafer 9 in the processing step of the manufacturing method (2-1). In manufacturing method (2-2), the cutting of the protective film-forming film 13 may be by a known method, for example, the same as the cutting method for the protective film-forming film 13 in the cutting step of manufacturing method (2-1).

[0283] Using the obtained protective film-forming chip 913, the protective film-forming chip 913 can be picked up by separating it from the support sheet 10, as shown in Figure 9(c). The process at this time may be the same as the pick-up process described in manufacturing method (2-1). In the pickup step of the manufacturing method (2-2), delamination occurs between the second surface 130b of the protective film forming film 130 in the protective film forming film chip 913 and the first surface 12a of the adhesive layer 12 in the support sheet 10.

[0284] When the protective film-forming chip 913 is picked up using a pushing mechanism such as a pushing needle pin, scratches such as indentations (needle marks) may be formed on the protective film-forming film 130 at the point where it was pushed up by the pushing mechanism.

[0285] After the pick-up step of the manufacturing method (2-2) described above, in the thermosetting step, the protective film forming film 130 on the protective film forming chip 913 is thermoset to form a protective film 130', thereby producing a protective film-coated chip 913'.

[0286] In Figure 9(d), reference numeral 130a' indicates the first surface of the protective film 130' and corresponds to the first surface 130a of the protective film-forming film 130 after cutting. Reference numeral 130b' indicates the second surface of the protective film 130' and corresponds to the second surface 130b of the protective film-forming film 130 after cutting.

[0287] The thermosetting step in manufacturing method (2-2) can be carried out in the same manner as the thermosetting step in manufacturing method (1-1).

[0288] When using a conventional protective film, if scratches such as dents (not shown) are formed on the surface 130b of the protective film 13 opposite to the wafer 9 side, the scratches will remain even after the heat curing process, resulting in the production of defective products. In contrast, in the manufacturing method (2-2) using the protective film forming film of this embodiment, even if scratches are formed on the surface of the protective film forming film 13, the scratches can be reduced in size by performing a heat curing process due to the self-healing effect of heating, making the scratches on the surface of the protective film 13' less noticeable.

[0289] The manufacturing method (2-2) preferably includes a heating step after the pickup step and before the heat curing step in which the protective film forming film 130 is heated under conditions that prevent the protective film forming film 130 from heat curing. By heating the protective film forming film 130 under conditions that prevent the protective film forming film 130 from heat curing, the surface scratches of the protective film forming film 130 can be reduced, and the surface scratches of the protective film 130' can be made less noticeable. The heating step in manufacturing method (2-2) can be carried out in the same manner as the heating step in manufacturing method (1-1).

[0290] Up to this point, we have described the case in which the protective film-forming composite sheet 101 shown in Figure 2 is used as the manufacturing method (2-2) described above. However, in the manufacturing method of a workpiece with a protective film according to this embodiment, other protective film-forming composite sheets such as the protective film-forming composite sheet 102 shown in Figure 3, the protective film-forming composite sheet 103 shown in Figure 4, and the protective film-forming composite sheet 104 shown in Figure 5 may also be used. When using the aforementioned other composite sheet for forming a protective film, the method for manufacturing a workpiece with a protective film according to this embodiment may include the aforementioned other steps performed at any given time, based on the differences in the configuration between the aforementioned other composite sheet for forming a protective film and the composite sheet 101 for forming a protective film shown in Figure 2.

[0291] Up to this point, we have described a method for manufacturing a chip with a protective film using a composite sheet for forming a protective film as the manufacturing method (2-2) described above. However, a chip with a protective film can also be manufactured by using a protective film forming film that does not constitute a composite sheet for forming a protective film, instead of the composite sheet for forming a protective film.

[0292] <<Variations in the manufacturing method of a workpiece with a protective coating>> The method for manufacturing a workpiece with a protective film according to this embodiment may include other steps that do not fall under any of the following categories: the bonding step, the processing step, the cutting step, the heating step, the thermosetting step, the pickup step, or the dicing sheet bonding step, as long as the effects of the present invention are not impaired. The aforementioned other steps can be arbitrarily selected depending on the purpose and are not particularly limited. The timing for performing the other processes can be appropriately selected depending on the content of those other processes.

[0293] Examples of other steps in the method for manufacturing the chip with the protective film include a backgrind tape application step of applying backgrind tape to the circuit surface of the wafer before the application step, and a backgrind tape removal step of removing the backgrind tape from the circuit surface of the wafer after the backgrind tape application step and before the processing step and the cutting step. The backgrind tape may be a known type, and the backgrind tape can be attached to the circuit surface of the wafer and removed from the circuit surface of the wafer by known methods.

[0294] In this specification, the term "attachment process" refers to a process of attaching the protective film-forming film, or the protective film-forming film in the protective film-forming composite sheet, to a target location on the workpiece (for example, the back surface of the wafer), which is not a "dicing sheet attachment process" or a "backgrind tape attachment process."

[0295] Another example of the other steps in the method for manufacturing the chip with the protective film is a printing step in which laser printing is performed on the side of the protective film forming film or protective film opposite to the wafer side or opposite to the chip side, after the bonding step and before the pickup step. Laser printing on a protective film or protective film can be performed by known methods.

[0296] ◇Manufacturing method for substrate devices (Method of using workpieces with protective coatings) After obtaining a workpiece with a protective film using the manufacturing method described above, the substrate device can be manufactured in the same manner as the conventional substrate device manufacturing method, except that this workpiece with a protective film is used instead of a conventional workpiece with a protective film.

[0297] One example of a manufacturing method for such a substrate device is a manufacturing method that includes a flip-chip connection step, in which a protruding electrode on a workpiece with a protective film, obtained using the protective film forming film, is brought into contact with a connection pad on a circuit board, thereby electrically connecting the protruding electrode and the connection pad on the circuit board. [Examples]

[0298] 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.

[0299] <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. MA: Methyl acrylate HEA: 2-hydroxyethyl acrylate 2EHA: 2-ethylhexyl acrylate 2EHMA: 2-ethylhexyl methacrylate GMA: Glycidyl methacrylate MMA: Methyl methacrylate BA: n-butyl acrylate EA: Ethyl acrylate

[0300] <Raw materials for manufacturing protective film-forming compositions> The raw materials used in the production of the protective film-forming composition are listed below.

[0301] [Polymer component (A)] (A)-1: Acrylic polymer obtained by copolymerizing 2EHA (65 parts by mass), MMA (25 parts by mass), and HEA (10 parts by mass) (weight-average molecular weight: 500,000, glass transition temperature: -38°C) (A)-2: Acrylic polymer obtained by copolymerizing BA (40 parts by mass), EA (25 parts by mass), MMA (30 parts by mass), and GMA (5 parts by mass) (weight-average molecular weight: 500,000, glass transition temperature: -9°C) (A)-3: Acrylic polymer obtained by copolymerizing 2EHA (30 parts by mass), EA (35 parts by mass), MMA (30 parts by mass), and GMA (5 parts by mass) (weight-average molecular weight: 500,000, glass transition temperature: -12°C) (A)-4: Copolymer obtained by copolymerizing 2EHA (73 parts by mass), MA (12 parts by mass), GMA (3 parts by mass), and HEA (12 parts by mass) (weight-average molecular weight: 550,000, glass transition temperature: -55°C) (A)-5: Copolymer obtained by copolymerizing 2EHA (12 parts by mass), MA (73 parts by mass), GMA (3 parts by mass), and HEA (12 parts by mass) (weight-average molecular weight: 550,000, glass transition temperature: -5°C) (A)-6: Copolymer obtained by copolymerizing 2EHMA (85 parts by mass), MA (7 parts by mass), and HEA (8 parts by mass) (weight-average molecular weight: 650,000, glass transition temperature: -9°C) (A)-7: Copolymer obtained by copolymerizing BA (60 parts by mass), MA (10 parts by mass), GMA (17 parts by mass), and HEA (13 parts by mass) (weight-average molecular weight: 500,000, glass transition temperature: -31°C) (A)-8: Copolymer obtained by copolymerizing MA (87 parts by mass) and HEA (13 parts by mass) (weight-average molecular weight: 450,000, glass transition temperature: 6°C)

[0302] [Epoxy resin (B1)] (B1)-1: Bisphenol A type epoxy resin (Mitsubishi Chemical Corporation "jER828", epoxy equivalent: 184~194 g / eq) (B1)-2: Dicyclopentadiene type epoxy resin (DIC Corporation's "Epiclon HP-7200", epoxy equivalent: 254~264 g / eq) (B1)-3: Bisphenol-type epoxy resin (Mitsubishi Chemical Corporation's "jER1055", epoxy equivalent: 800-900 g / eq) (B1)-4: Dicyclopentadiene type epoxy resin (XD-1000, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 248 g / eq) (B1)-5: Dicyclopentadiene type epoxy resin (DIC Corporation's "Epiclon HP-7200HH", epoxy equivalent: 274~286 g / eq) [Thermosetting agent (B2)] (B2)-1: Dicyandiamide (thermally active latent epoxy resin curing agent, "DICY7" manufactured by Mitsubishi Chemical Corporation)

[0303] [Curing accelerator (C)] (C)-1:2-phenyl-4,5-dihydroxymethylimidazole (Shikoku Chemicals Co., Ltd. "Curesol 2PHZ") [Filling material (D)] (D)-1: Silica filler (SC2050MA, manufactured by Admatex, spherical silica filler with epoxy group surface modification, average particle size: 0.5 μm) (D)-2: Silica filler (crushed "SV-10" manufactured by Ryumori Co., Ltd. (spherical silica filler with an average particle size of 10 μm), average particle size after crushing: 2.0 μm) (D)-3: Silica filler (Admatex "SC105G-MMQ", spherical silica filler surface modified with vinyl groups, average particle size: 0.3 μm) (E)-1: Oligomer-type silane coupling agent having epoxy, methyl, and methoxy groups (Shin-Etsu Chemical Co., Ltd. "X-41-1056", epoxy equivalent 280 g / eq) [Coloring agent (I)] (I)-1: Organic black pigment (Dainichi Seika Kogyo Co., Ltd. "6377 Black") (I)-2: Carbon black (Mitsubishi Chemical Corporation "MA-600")

[0304] [Example 1] <<Manufacturing of protective film-forming film>> <Manufacturing of protective film-forming composition (III)-1> Polymer component (A)-1 (30.1 parts by mass), epoxy resin (B1)-1 (12.0 parts by mass), epoxy resin (B1)-2 (6.0 parts by mass), thermosetting agent (B2)-1 (0.4 parts by mass), curing accelerator (C)-1 (0.4 parts by mass), filler (D)-1 (48.1 parts by mass), coupling agent (E)-1 (0.4 parts by mass), and coloring agent (I)-1 (2.5 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain thermosetting protective film-forming composition (III)-1, in which the total concentration of all components other than the solvent was 60% by mass. The amounts of components other than methyl ethyl ketone shown here are all amounts of the target product excluding the solvent.

[0305] <Manufacturing of protective film-forming films> A release film (second release film, Lintec Corporation's "SP-PET502150", 50 μm thick) made of polyethylene terephthalate film, in which one side was treated with silicone for release, was used. The protective film-forming composition (III)-1 obtained above was applied to the release-treated surface, and the film was dried at 100°C for 2 minutes to produce a thermosetting protective film-forming film with a thickness of 40 μm.

[0306] Furthermore, a protective film-forming film with a release film was manufactured by laminating the release-treated surface of a release film (first release film, Lintec Corporation's "SP-PET381031", thickness 38 μm) to the exposed surface of the obtained protective film-forming film that does not have a second release film, under the conditions of a lamination speed of 2 m / min, a lamination temperature of 60°C, and a lamination pressure of 0.5 MPa, thereby 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] <<Evaluation of protective film-forming film>> <Measurement of Storage Modulus E'(70) and E'(90) of Protective Film Forming Film> Using the five protective film-forming films with release films obtained above, the exposed surfaces of the protective film-forming films were sequentially bonded together while removing either the first or second release film, thereby creating a laminate in which the second release film, the five protective film-forming films (total thickness 200 μm), and the second release film were stacked in this order. Then, from this laminate, sections with a width of 4 mm and a length of 30 mm were cut out so that the length direction was the MD direction of the protective film-forming film. Next, the two outermost second release films were removed from this section, and the resulting specimen was used as the test piece. Next, using a dynamic viscoelasticity automatic measuring device (A&D Corporation's "Reovibron DDV-01FP"), the storage modulus E' of the test specimen was measured using the tensile method (tensile mode) under the following measurement conditions: chuck distance of 20 mm, frequency of 11 Hz, heating rate of 3 °C / min, and constant heating rate, in the temperature range from -50 °C to 150 °C. The storage modulus E'(70) at 70 °C and the storage modulus E'(90) at 90 °C are shown in Table 1. In addition, the tanδ(70) at 70 °C and the tanδ(90) at 90 °C are also shown in Table 1.

[0308] <Measurement of the storage modulus E'(23) of the protective film> Similarly to the above, a laminate was prepared by stacking the second release film, five protective film-forming films (total thickness 200 μm), and the second release film in this order. From this laminate, a section with a width of 5 mm and a length of 30 mm was cut out so that the length direction was the MD direction of the protective film-forming film. This section was heated at 90°C for 2 hours, then further heated in two stages at 130°C for 2 hours. Subsequently, the two outermost second release films were removed from this section, and the resulting specimen was used as the test piece. Next, using a dynamic viscoelasticity measuring device (TA Instruments "DMAQ800"), the storage modulus E' of the test specimen was measured using the tensile method (tensile mode) under the following measurement conditions: chuck distance of 20 mm, frequency of 11 Hz, heating rate of 3 °C / min, and constant heating rate, in the temperature range from -60 °C to 300 °C. The storage modulus E'(23) at 23 °C is shown in Table 1.

[0309] <Evaluation of self-healing ability (A)> Using a tape laminator (Lintec Corporation, RAD-3600F / 12), the first release film was removed from the protective film-forming film with release film obtained above. By pressing a laminating roll with a piece of debris (tiny silicon foreign matter) measuring 40 μm thick, 0.25 mm long, and 0.25 mm wide sandwiched between the second release film side, the exposed protective film-forming film was attached to the ground surface of a silicon wafer (8 inches in diameter, 350 μm thick, #2000 ground), thereby creating a laminate in which the silicon wafer, protective film-forming film, and second release film were stacked in this order. After peeling off the second release film, the surface of the protective film-forming film was observed with a laser microscope (Keyence Corporation, VK-9700). A scratch with a depth of approximately 2.03 μm (i.e., the depth of the scratch before heating) was observed on the surface of the protective film-forming film due to the embedded debris.

[0310] A protective film-forming film with scratches on its surface was heated at 90°C for 2 hours. Similarly, when the surface of the protective film-forming film after heating was observed with a laser microscope, scratches with a depth of approximately 0.26 μm (i.e., the depth of the scratches after heating) were observed on the surface of the protective film-forming film.

[0311] The self-repair rate (A) [%] obtained by heating at 90°C for 2 hours was calculated using the following formula, rounding the value to one decimal place to obtain an integer. Self-healing rate (A) [%] = {(Depth of scratch before heating - Depth of scratch after heating) / Depth of scratch before heating} × 100

[0312] Furthermore, the self-repair rate (A) [%] and the evaluation results based on the following criteria are shown in Table 1. A: 100-80% B: 79-60% C: 59-35% D: 34-15% E: 14-0%

[0313] <Evaluation of self-healing ability (C)> A protective film-forming film, similar to the one described above, with scratches on its surface that were 2.07 μm deep before heating, was heated at 90°C for 2 hours, and then at 130°C for 2 hours to form a protective film. Similarly, when the surface of the protective film was observed with a laser microscope, scratches with a depth of approximately 0.18 μm (i.e., the depth of the scratches after heating at 90°C and then further heat curing) were observed on the surface of the protective film.

[0314] The self-repair rate (C) [%] obtained by heating at 130°C for 2 hours was calculated using the following formula, rounding the value to one decimal place to obtain an integer. Self-healing rate (C) [%] = {(Depth of scratch before heating - Depth of scratch after heating to 90°C and further heat hardening) / Depth of scratch before heating} × 100

[0315] The self-repair rate (C) [%] and the evaluation results based on the following criteria are shown in Table 1. A: 100-80% B: 79-60% C: 59-35% D: 34-15% E: 14-0%

[0316] <Evaluation of self-healing ability (B)> A protective film-forming film, similar to the one described above, with scratches on its surface that were 2.01 μm deep before heating, was heated at 130°C for 2 hours to form a protective film. Similarly, when the surface of the protective film was observed with a laser microscope, scratches with a depth of approximately 0.80 μm (i.e., the depth of the scratches after heat curing) were observed on the surface of the protective film.

[0317] The self-repair rate (B) [%] obtained by heating at 130°C for 2 hours was calculated using the following formula, rounding the value to one decimal place to obtain an integer. Self-healing rate (B) [%] = {(Depth of scratch before heating - Depth of scratch after heat hardening) / Depth of scratch before heating} × 100

[0318] The self-repair rate (B) [%] and the evaluation results based on the following criteria are shown in Table 1. (Evaluation Criteria) A: 100-80% B: 79-60% C: 59-35% D: 34-15% E: 14-0%

[0319] <<Manufacturing of protective film-forming films and evaluation of protective film-forming films>> [Examples 2-7, Comparative Examples 1-2] Except for changing the types of components used in the formulation so that the components and their contents of the protective film-forming film are as shown in Table 1 or Table 2, the protective film-forming film and the composite sheet for protective film formation were manufactured using the same method as in Example 1, and the protective film-forming film was evaluated. The results are shown in Table 1 or Table 2.

[0320] [Table 1]

[0321] [Table 2]

[0322] As is clear from the results above, the protective film-forming films of Comparative Examples 1 and 2 did not exhibit a self-healing effect when heated at 90°C for 2 hours. Furthermore, the protective film-forming films of Comparative Examples 1 and 2 did not exhibit a self-healing effect when heated at 130°C for 2 hours, which is a normal heat curing condition. No self-healing effect was observed even when heated at 90°C for 2 hours or at 130°C for 2 hours.

[0323] In contrast to these, the protective film-forming films of Examples 1 to 7 showed a self-healing effect when heated at 90°C for 2 hours. Furthermore, the protective film-forming films of Examples 1 to 7 also showed a self-healing effect when heated at 130°C for 2 hours, which is a normal heat curing condition. Moreover, superior self-healing effects were observed when heated at 90°C for 2 hours and 130°C for 2 hours compared to the normal heat curing condition of 130°C for 2 hours. Therefore, even if scratches are formed on the surface of the protective film-forming film during the process of manufacturing a workpiece with a protective film or a workpiece processed with a protective film using the protective film-forming film of the present invention or a composite sheet for forming a protective film comprising the protective film-forming film of the present invention, the scratches on the surface of the protective film after heat curing of the protective film-forming film can be made less noticeable. [Industrial applicability]

[0324] This invention can be used in the manufacture of various substrate devices, including semiconductor devices. [Explanation of Symbols]

[0325] 10,20...Support sheet, 10a,20a...One side (first side) of the support sheet, 11...Base material, 12. Adhesive layer, 13,23...Protective film forming film, 130... Protective film formed after cutting, 13',130'...protective film, 15, 151, 152... Release film, 16...Laminating roll, 17...Foreign object, 18...Indentation marks, 19...Contact marks 101, 102, 103, 104... Composite sheets for forming protective films, 9...wafer, 9b...back side of wafer, The reverse side of the 90... chip and the 90b... chip. 901...Wafer with protective film formation film, 902...Wafer with protective film, 903...Chip group with protective film formation film, 904... Group of chips with protective film, 905...Chip group with protective film formation film, 913...Chip with protective film 913'... Protective film-covered tip

Claims

1. A thermosetting protective film, It contains acrylic resin, epoxy resin, thermosetting agent and filler, When a 4 mm wide test specimen of the protective film-forming film is held at two locations with a 20 mm gap between them, and the storage modulus E' of the test specimen is measured while the test specimen is heated from -50°C to 150°C under tensile mode conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, the storage modulus E'(90) of the test specimen at 90°C is 5 MPa or less. A protective film-forming film in which a 4 mm wide test piece of the protective film-forming film is held at two locations with a 20 mm gap between them, and the tanδ of the test piece is measured while the test piece is heated from -50°C to 150°C under the conditions of constant heating, frequency of 11 Hz, heating rate of 3°C / min, in tensile mode, and the tanδ of the test piece at 90°C is 0.20 or more.

2. A thermosetting protective film, It contains acrylic resin, epoxy resin, thermosetting agent and filler, When a 4 mm wide test specimen of the protective film-forming film is held at two locations with a 20 mm gap between them, and the storage modulus E' of the test specimen is measured while the test specimen is heated from -50°C to 150°C under tensile mode conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, the storage modulus E'(90) of the test specimen at 90°C is 5 MPa or less. A protective film-forming film in which a 4 mm wide test piece of the protective film-forming film is held at two locations with a 20 mm gap between them, and the tanδ of the test piece is measured while the test piece is heated from -50°C to 150°C under the conditions of constant heating, frequency of 11 Hz, heating rate of 3°C / min, in tensile mode, and the tanδ of the test piece at 70°C is 0.35 or more.

3. The protective film forming film according to claim 1 or 2, wherein a 4 mm wide test piece of the protective film forming film is held at two locations with a 20 mm gap between them, and the tanδ of the test piece is measured while the test piece is heated from -50°C to 150°C under the conditions of a tensile mode, a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the tanδ of the test piece at 90°C is 0.34 or more.

4. A protective film-forming film according to any one of claims 1 to 3, wherein a 5 mm wide test piece of a thermoset product obtained by heat-curing the protective film-forming film is held at two locations with a 20 mm gap between them, and the storage modulus E' of the test piece is measured while heating the test piece from -60°C to 300°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the storage modulus E' of the test piece at 23°C is 100 MPa or more.

5. It contains a polymer component (A) including acrylic resin, The protective film forming film according to any one of claims 1 to 4, wherein the glass transition temperature of the acrylic resin is less than 10°C.

6. It contains filler (D), The protective film forming film according to any one of claims 1 to 5, wherein the ratio of the content of the filler (D) to the total mass of the protective film forming film is less than 50% by mass.

7. It comprises 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 any one of claims 1 to 6.

8. A method for manufacturing a workpiece with a protective film, The aforementioned workpiece with protective film comprises a workpiece and a protective film provided on any part of the workpiece. The manufacturing method includes a bonding step of bonding a protective film-forming film to a workpiece comprising the workpiece and the protective film-forming film, by bonding the protective film-forming film described in any one of claims 1 to 6, or the protective film-forming film in the protective film-forming composite sheet described in claim 7, to a target location on the workpiece, A method for manufacturing a workpiece with a protective film, comprising a heat curing step of producing the workpiece with a protective film by heat curing the protective film-forming film after the bonding step to form the protective film.

9. A method for manufacturing a workpiece with a protective film, The aforementioned workpiece with protective film comprises a workpiece obtained by processing a workpiece, and a protective film provided on any part of the workpiece. The manufacturing method includes a bonding step of bonding a protective film-forming film to a workpiece comprising the workpiece and the protective film-forming film, by bonding the protective film-forming film described in any one of claims 1 to 6, or the protective film-forming film in the protective film-forming composite sheet described in claim 7, to a target location on the workpiece, A processing step is performed to produce the workpiece by processing the workpiece after the aforementioned bonding step, A method for manufacturing a workpiece with a protective film, comprising a heat curing step of forming the protective film by heat curing the protective film-forming film after the aforementioned bonding step.

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