Protective film-forming film, composite sheet for protective film formation, method for manufacturing workpiece with protective film, and method for manufacturing workpiece with protective film

Abstract

To provide a thermosetting protective membrane-forming film which, when a processed workpiece with a protective membrane is produced by pasting a protective membrane-forming film on a workpiece, thereafter preparing a processed workpiece by processing the workpiece, and forming a protective membrane by thermally curing the protective membrane-forming film, can suppress occurrence of abnormalities in the protective membrane even when the protective membrane-forming film is thermally cured at a higher temperature than heretofore.SOLUTION: Provided is a thermosetting protective membrane-forming film 13 which is a laminate of a plurality of protective membrane-forming films 13. When a test piece of a width of 4 mm is held at two places with an interval of 20 mm and a storage modulus E' of the test piece is measured by a tension mode under conditions of a frequency of 11 Hz, a rate of temperature increase of 3°C / min, and a constant rate temperature increase while raising the temperature of the test piece from -10°C to 170°C, the storage modulus E' of the test piece becomes 1 MPa or more in all temperature range of 160°C to 170°C.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 Art

[0002] In wafers such as semiconductor wafers and insulator wafers, a circuit is formed on one surface (the circuit surface), and some have protruding electrodes such as bumps on that surface (the circuit surface). Such wafers are diced into chips, and the protruding electrodes are connected to connection pads on the circuit board, whereby they are mounted on the circuit board. In such wafers and chips, in order to suppress damage such as crack generation, the surface (the back surface) opposite to the circuit surface may be protected with a protective film.

[0003] To form such a protective film, a protective film-forming film for forming a protective film is attached to the back surface of the wafer. The protective film-forming film may be laminated on a support sheet for supporting it and used in the state of a composite sheet for forming a protective film, or may be used without being laminated on the support sheet (see Patent Document 1). Next, a wafer having a protective film-forming film on the back surface (a wafer with a protective film-forming film) is processed through subsequent various processes into a chip having a protective film on the back surface (a chip with a protective film). Such a chip with a protective film is mounted on a circuit board after being picked up and constitutes various substrate devices (for example, semiconductor devices).

[0004] The chip with a protective film can be manufactured, for example, by manufacturing the above-mentioned wafer with a protective film-forming film, then dicing the wafer to manufacture chips, cutting the protective film-forming film, and manufacturing a chip having the cut protective film-forming film on the back surface (a chip with a protective film-forming film), and further curing the cut protective film-forming film to form a protective film.

[0005] Further, the chip with the protective film can be manufactured, for example, by producing the wafer with the protective film forming film as described above, then curing the protective film forming film therein to form a protective film, then dividing the wafer to produce chips, and cutting the protective film.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] As the protective film forming film, a thermosetting protective film forming film that can form a protective film by heating and thermosetting it is widely used. The thermosetting protective film forming film is often thermoset at a temperature of about 120 to 130°C, for example. On the other hand, such thermosetting at this temperature is usually performed for several hours. Therefore, in the manufacturing process of the chip with the protective film, it is desired to shorten the time required for the entire process by shortening the time required for this thermosetting. For this purpose, it is conceivable to increase the heating temperature when thermosetting the protective film forming film.

[0008] However, as described above, when a chip having the protective film forming film on the back surface after cutting, that is, a chip with the protective film forming film, is produced and the protective film forming film after cutting is heated at a higher temperature than before, the fluidity of the protective film forming film becomes higher than before before the protective film forming film is sufficiently cured. Then, between the chips with the protective film forming film existing in the vicinity, the protective film forming films are likely to contact each other. When they contact and adhere, the curing of the protective film forming film proceeds in this adhered state, and defective products in which a plurality of chips are connected by the protective film are produced.

[0009] Also, as described above, after manufacturing a wafer with a protective film forming film, when the protective film forming film in it is heated at a higher temperature than before, still, before the protective film forming film is sufficiently cured, the fluidity of the protective film forming film becomes higher than before. Then, at the peripheral portion along the outer periphery of the wafer in the wafer with the protective film forming film, the protective film forming film is deformed, and typically, the thickness becomes thinner in the portion closer to the outer periphery. Such a phenomenon is also liable to be affected by the hot air generated during heating. In such a case, then, when the wafer is divided to produce chips and the protective film is cut to produce chips with a protective film, in the chips with a protective film produced from the portion closer to the outer periphery of the wafer, the thickness of the protective film is thinner than normal or the protective film forms an inclined surface, and still defective products are produced.

[0010] Thus, when forming a protective film, when the protective film forming film is heated at a higher temperature than before, various abnormalities occur in the formed protective film. And the protective film forming film disclosed in Patent Document 1 is not intended to solve such problems.

[0011] Here, the problems when the protective film forming film is heated at a higher temperature than before have been described by taking the case of producing chips from a wafer as an example, but such problems can also occur when processing workpieces other than wafers.

[0012] The present invention provides a thermosetting protective film forming film, which is used to attach the protective film forming film to a workpiece, then process the workpiece to produce a processed workpiece, and thermally cure the protective film forming film to form a protective film, so that when manufacturing a processed workpiece with a protective film, even if the protective film forming film is thermally cured at a higher temperature than before, abnormal occurrence in the protective film can be suppressed. The present invention also provides a composite sheet for forming a protective film including the protective film forming film, and a method for manufacturing a processed workpiece with a protective film using the protective film forming film or the composite sheet for forming a protective film.

Means for Solving the Problems

[0013] The present invention provides a thermosetting protective film-forming film, which is a laminate of multiple sheets of the protective film-forming film, and when a 4 mm wide test piece is held at two points 20 mm apart and the storage modulus E' of the test piece is measured while heating the test piece from -10°C to 170°C in a tensile mode under conditions of a frequency of 11 Hz, a heating rate of 3°C / min and a uniform heating rate, the storage modulus E' of the test piece is 1 MPa or more in the entire temperature range from 160°C to 170°C.

[0014] The thermoset product obtained by heating the protective film-forming film of the present invention in a temperature range of 160 to 170° C. for 1 hour preferably has a transmittance of 90% or less at a wavelength of 550 nm. The thickness of the protective film of the present invention is preferably less than 50 μm.

[0015] The present invention provides a composite sheet for forming a protective film, comprising a support sheet and a protective film-forming film provided on one side of the support sheet, wherein the protective film-forming film is the protective film-forming film of the present invention described above. The present invention provides a method for manufacturing a workpiece with a protective film, the workpiece with a protective film comprising a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, the manufacturing method comprising: an attachment step of attaching the protective film-forming film of the present invention or the protective film-forming film in the composite sheet for forming a protective film of the present invention to a desired location on the workpiece to produce a workpiece with a protective film-forming film comprising the workpiece and the protective film-forming film; a processing step of processing the workpiece after the attachment step to produce the workpiece; a cutting step of cutting the protective film-forming film after the attachment step; and a heat-curing step of heat-curing the protective film-forming film after the cutting at a temperature of 160 to 170°C to form the protective film, to produce the workpiece with a protective film, after the processing step and the cutting step.

[0016] The present invention provides a method for manufacturing a workpiece with a protective film, wherein the workpiece with a protective film includes a workpiece and a protective film provided at any location of the workpiece. The manufacturing method includes an attaching step of attaching the protective film forming film of the present invention or the protective film forming film in the composite sheet for forming a protective film of the present invention to a target location of the workpiece to produce a workpiece with a protective film forming film including the workpiece and the protective film forming film, and a thermosetting step of thermosetting the protective film forming film at a temperature of 160 to 170°C to form the protective film, thereby producing the workpiece with a protective film.

Effects of the Invention

[0017] According to the present invention, when manufacturing a workpiece with a protective film by attaching a protective film forming film to a workpiece, then processing the workpiece to produce a processed workpiece, and thermosetting the protective film forming film to form a protective film, even if the protective film forming film is thermoset at a higher temperature than before, a protective film forming film capable of suppressing the occurrence of abnormalities in the protective film, a composite sheet for forming a protective film including the protective film forming film, and a method for manufacturing a processed workpiece with a protective film using the protective film forming film or the composite sheet for forming a protective film are provided.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0019] ◇Protective Film Forming Film The protective film forming film according to an embodiment of the present invention is a thermosetting protective film forming film, which is a laminate of a plurality of the protective film forming films. When a test piece with a width of 4 mm is held at two locations with an interval of 20 mm and the storage elastic modulus E' of the test piece is measured while raising the temperature of the test piece from -10°C to 170°C under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and a constant heating rate in a tensile mode, the storage elastic modulus E' of the test piece is 1 MPa or more in all temperature ranges from 160°C to 170°C. The protective film forming film of the present embodiment can form a composite sheet for forming a protective film by laminating with a support sheet, for example, as described later.

[0020] In the present embodiment, examples of the workpiece include wafers such as semiconductor wafers and semiconductor device panels. A semiconductor device panel is handled in the manufacturing process of a semiconductor device. As a specific example, a semiconductor device in which one or two or more electronic components are encapsulated with a sealing resin is used, and a plurality of these semiconductor devices are planarized and arranged within a region having a shape such as a circle or a rectangle. In this specification, a processed workpiece is referred to as a “workpiece artifact.” For example, if the workpiece is a semiconductor wafer, an example of the workpiece artifact is a semiconductor chip.

[0021] By using the protective film-forming film of this embodiment or a composite sheet for forming a protective film including the same, it is possible to manufacture a workpiece with a protective film, which includes a workpiece and a protective film provided at any location on the workpiece. For example, when the workpiece is a wafer, it is possible to manufacture a chip with a protective film, which includes 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.

[0022] In this specification, the term "wafer" refers to semiconductor wafers made of elemental semiconductors such as silicon, germanium, and selenium, and compound semiconductors such as GaAs, GaP, InP, CdTe, ZnSe, and SiC; and insulating wafers made of insulators such as sapphire, glass, lithium niobate, and lithium tantalate. A circuit is formed on one surface of each of these wafers, and in this specification, the surface of the wafer on which the circuit is formed is referred to as the "circuit side," and the surface of the wafer opposite the circuit side is referred to as the "back side." The wafer is divided into chips by dicing or other means. In this specification, as with the wafer, the surface of the chip on which the circuit is formed is referred to as the "circuit side," and the surface of the chip opposite the circuit side is referred to as the "back side." It is preferable that both the circuit surface of the wafer and the circuit surface of the chip are provided with protruding electrodes such as bumps, pillars, etc. The protruding electrodes are preferably made of solder.

[0023] Furthermore, by using the chip with the protective film, a substrate device can be manufactured. In this specification, the term "substrate device" refers to a device in which a chip with a protective film is flip-chip connected to connection pads on a circuit board at protruding electrodes on the circuit surface of the chip. For example, if a semiconductor wafer is used as the wafer, the substrate device may be a semiconductor device.

[0024] Since the storage modulus E' of the test piece is 1 MPa or more in the entire temperature range from 160°C to 170°C, when the protective film-forming film of this embodiment is used to manufacture the protective film-equipped workpiece, the occurrence of abnormalities in the protective film can be suppressed even if the protective film-forming film is thermally cured at a higher temperature than conventionally. More specifically, for example, adhesion of the protective films between adjacent protective film-equipped workpieces can be suppressed, and in the protective film-equipped workpiece, deformation of the protective film arranged on the peripheral portion of the workpiece can be suppressed. The protective film-equipped workpiece becomes a protective film-equipped workpiece by processing the workpiece. In this way, the protective film-forming film of this embodiment can suppress the occurrence of abnormalities in the protective film even when thermally cured at a higher temperature than conventionally, and therefore, by using the protective film-forming film of this embodiment, the workpiece with the protective film can be manufactured in a shorter time than conventionally possible.

[0025] The protective film-forming film of the present embodiment has thermosetting properties and functions as a protective film by the thermal curing.

[0026] A protective film-forming film at room temperature is heated to a temperature above room temperature and then cooled to room temperature to obtain a protective film-forming film after heating and cooling.When the hardness of the protective film-forming film after heating and cooling is compared with the hardness of the protective film-forming film before heating at the same temperature, if the protective film-forming film after heating and cooling is harder, then the protective film-forming film is thermosetting.

[0027] The protective film-forming film may be composed of one layer (single layer) or two or more layers. When the protective film-forming film is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

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

[0029] The storage modulus E' is measured by stacking a plurality of protective film-forming films and cutting them to prepare a laminate having a width of 4 mm, and using this laminate as a test piece. More specifically, the test piece is held at two positions spaced 20 mm apart, and in this state, the test piece is heated at a constant rate of 3°C / min from -10°C to 170°C, while measuring the storage modulus E' of the test piece under the condition of a frequency of 11 Hz. The test piece is held at two points with a gap of 20 mm between them, which means that the length of the portion of the test piece to be measured for storage modulus E' is 20 mm.

[0030] The test piece can be held at the two locations using, for example, a holding means such as a known gripper.

[0031] The thickness of the test piece (laminate) is not particularly limited as long as it does not interfere with the execution of the test and does not impair the measurement accuracy of the storage modulus E'. Generally, the thickness of the test piece is preferably 190 to 210 μm, more preferably 195 to 205 μm, and particularly preferably 200 μm.

[0032] The number of protective film forming films constituting the test piece is not particularly limited as long as it is 2 or more, and can be arbitrarily selected according to the thickness of each protective film forming film. For example, the test piece can be produced by using 5 protective film forming films with a thickness of 40 μm. However, this is just an example, and the number and thickness of the protective film forming films used are not limited to this.

[0033] The storage elastic modulus E' shown by the test piece in all temperature ranges from 160°C to 170°C is not particularly limited as long as it is 1 MPa or more, but it is preferably 3 MPa or more, more preferably 5 MPa or more, and for example, it may be any of 10 MPa or more, 20 MPa or more, and 30 MPa or more. The higher the storage elastic modulus E', the higher the effect of suppressing the occurrence of abnormalities in the above-mentioned protective film.

[0034] The upper limit value of the storage elastic modulus E' shown by the test piece in all temperature ranges from 160°C to 170°C is not particularly limited. In all temperature ranges from 160°C to 170°C, a protective film forming film with a storage elastic modulus E' of the test piece of 350 MPa or less is highly feasible, and the storage elastic modulus E' may be, for example, any of 200 MPa or less, 150 MPa or less, and 120 MPa or less.

[0035] The storage modulus E' of the test piece over the entire temperature range from 160°C to 170°C can be appropriately adjusted within a range set by arbitrarily combining any of the lower limit values and any of the upper limit values described above. For example, in one embodiment, the storage elastic modulus E' may be any of 1 to 350 MPa, 3 to 350 MPa, 5 to 350 MPa, 10 to 350 MPa, 20 to 350 MPa, and 30 to 350 MPa, or any of 1 to 200 MPa, 3 to 200 MPa, 5 to 200 MPa, 10 to 200 MPa, 20 to 200 MPa, and 30 to 200 MPa, or any of 1 to 150 MPa, 3 to 150 MPa, 5 to 150 MPa, 10 to 150 MPa, 20 to 150 MPa, and 30 to 150 MPa, or any of 1 to 120 MPa, 3 to 120 MPa, 5 to 120 MPa, 10 to 120 MPa, 20 to 120 MPa, and 30 to 120 MPa.

[0036] It is preferable that the test piece exhibits a higher storage modulus E' as the temperature increases in the temperature range of 160°C to 170°C. That is, the protective film-forming film preferably exhibits an increase in storage modulus E' with increasing temperature of the test piece in a temperature range of 160° C. to 170° C. Such a protective film-forming film exhibits a higher effect of suppressing the occurrence of abnormalities in the protective film described above.

[0037] The storage modulus E' (sometimes referred to herein as "E'(160)") exhibited by the test piece at a temperature of 160°C may be the same as the above-mentioned lower limit value of the storage modulus E' exhibited by the test piece in the entire temperature range from 160°C to 170°C. The storage modulus E' (sometimes referred to herein as "E'(170)") of the test piece at a temperature of 170°C may be the same as the upper limit value of the storage modulus E' of the test piece in the entire temperature range from 160°C to 170°C. For example, E'(170) may be higher than E'(160).

[0038] The storage modulus E' of the test piece can be adjusted by adjusting the type and content of the components contained in the protective film-forming film. For example, when the protective film-forming film contains the polymer component (A) described below, the storage modulus E' of the test piece can be more easily adjusted by adjusting the type and amount of the structural units contained in the polymer component (A). More specifically, for example, by using an acrylic resin having a certain amount or more of structural units derived from acrylonitrile or acrylic acid as the polymer component (A) and adjusting the content thereof, the storage modulus E' of the test piece can be more easily adjusted. In addition, for example, when the protective film-forming film contains a filler (D) described later, the storage modulus E' of the test piece can be more easily adjusted by adjusting the average particle size of the filler (D). Typically, the smaller the average particle size of the filler (D), the larger the storage modulus E' of the test piece tends to be.

[0039] In this specification, unless otherwise specified, the term "average particle size" refers to the particle size at 50% of the integrated value in a particle size distribution curve obtained by a laser diffraction scattering method (D 50 ) value.

[0040] The thickness of the protective film-forming film is preferably less than 50 μm, more preferably 43 μm or less, and may be, for example, 40 μm or less. By making the thickness of the protective film-forming film equal to or less than the upper limit, the effect of suppressing the occurrence of abnormalities in the protective film described above is enhanced.

[0041] The thickness of the protective film-forming film is preferably 5 μm or more in terms of forming a protective film with higher protective performance.

[0042] The thickness of the protective film-forming 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-forming film may be any of 5 μm or more and less than 50 μm, 5 to 43 μm, and 5 to 40 μm.

[0043] In this specification, the "thickness of the protective film-forming film" means the thickness of the entire protective film-forming film. For example, the thickness of a protective film-forming film composed of multiple layers means the total thickness of all the layers constituting the protective film-forming film.

[0044] In this specification, not limited to the case of the protective film-forming film, the "thickness" is, unless otherwise specified, a value represented by 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.

[0045] The transmittance of light with a wavelength of 550 nm (which may be referred to as "light (550 nm) transmittance" in this specification) of the thermoset obtained by heating the protective film-forming film in a temperature range of 160 to 170 °C for 1 hour is not particularly limited, but is preferably 90% or less, and may be, for example, any of 70% or less, 50% or less, 30% or less, and 20% or less. When the light (550 nm) transmittance of the thermoset is at or below the upper limit value, the protective film formed from the protective film-forming film can be easily recognized and has a more favorable appearance.

[0046] The lower limit value of the light (550 nm) transmittance of the thermoset is not particularly limited. For example, a protective film-forming film with a light (550 nm) transmittance of 1% or more of the thermoset can be manufactured more easily.

[0047] The light (550 nm) transmittance of the thermoset can be appropriately adjusted within a range set by arbitrarily combining any of the above upper limit values and lower limit values. For example, in one embodiment, the light (550 nm) transmittance of the thermoset may be any of 1 to 90%, 1 to 70%, 1 to 50%, 1 to 30%, and 1 to 20%.

[0048] Not limited to the light (550 nm) transmittance, the light transmittance of the thermoset can be adjusted by adjusting the type and content of the components contained in the protective film-forming film. For example, when the protective film-forming film contains the colorant (I) described below, the light transmittance of the thermoset product can be more easily adjusted by adjusting the type of colorant (I) and its content in the protective film-forming film.

[0049] In the present embodiment, it is preferable that the thermoset product obtained by heating the protective film-forming film in a temperature range of 160 to 170° C. for 1 hour functions as a protective film.

[0050] The curing conditions when the protective film-forming film is attached to the desired location on the wafer and thermally cured to form a protective film are not particularly limited, as long as the protective film is cured to a degree that allows it to fully perform its function, and may be selected appropriately depending on the type of protective film-forming film.

[0051] For example, the heating temperature during thermal curing of the protective film-forming film may be any of 100 to 200° C., 110 to 180° C., and 120 to 170° C. However, in the present embodiment, when the heating temperature is 160 to 170° C., the effect of the protective film-forming film becomes particularly remarkable.

[0052] The heating time during the thermal curing may be appropriately set in consideration of the heating temperature, and may be, for example, any one of 0.5 to 5 hours, 0.5 to 3 hours, and 1 to 2 hours. For example, when the heating temperature is 160 to 170° C. and the heating time is 0.5 to 1 hour, the effect of the protective film-forming film becomes particularly remarkable.

[0053] <<Composition for forming protective film>> The protective film-forming film can be formed using a composition for forming a protective film (more specifically, a thermosetting composition for forming a protective film) containing its constituent materials. For example, the protective film-forming film can be formed by applying the composition for forming a protective film to the surface to be formed and drying it as necessary. The ratio of the contents of the components that do not vaporize at normal temperature in the composition for forming a protective film is usually the same as the ratio of the contents of the said components in the protective film-forming film. In this specification, "normal temperature" means a temperature that is not particularly cooled or heated, that is, an ordinary temperature, and examples thereof include a temperature of 15 to 25°C.

[0054] In addition to being thermosetting, the protective film-forming film may have energy ray curability.

[0055] In this specification, "energy ray" means those having energy quanta among electromagnetic waves or charged particle beams, and examples thereof include ultraviolet rays, radiation, electron beams, etc. Ultraviolet rays can be irradiated, for example, by using a high-pressure mercury lamp, a xenon lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet ray source. Electron beams can be irradiated with those generated by an electron beam accelerator or the like. In this specification, "energy ray curability" means the property of curing by irradiating with energy rays, and "non-energy ray curability" means the property of not curing even when irradiated with energy rays.

[0056] The application of the composition for forming a protective film may be carried out by a known method. For example, methods using various coaters such as an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater, a screen coater, a Meyer bar coater, and a kiss coater can be mentioned.

[0057] The drying conditions for the protective film-forming composition are not particularly limited. However, when the protective film-forming composition contains a solvent, which will be described later, it is preferable to heat-dry it. The protective film-forming composition containing the solvent is preferably heat-dried, for example, at 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 so as not to thermally cure the composition itself or the thermosetting protective film-forming film formed from this composition.

[0058] A preferred protective film-forming film includes, for example, one containing a polymer component (A), a thermosetting component (B), and a filler (D). The polymer component (A) is a component that can be considered to be formed by a polymerization reaction of a polymerizable compound. The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction when heat is used as a reaction trigger. In this specification, polymerization reaction also includes polycondensation reaction. The composition for forming a protective film will be described in detail below.

[0059] <Protective film forming composition (III)> A preferred example of a composition for forming a protective film is a composition for forming a protective film (III) (sometimes abbreviated herein as "composition (III)") containing the polymer component (A), the thermosetting component (B), and the filler (D).

[0060] [Polymer component (A)] The polymer component (A) is a polymer compound for imparting film-forming properties, flexibility, etc. to the protective film-forming film. In this specification, the polymer compound also includes products of polycondensation reactions.

[0061] The polymer component (A) contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0062] Examples of the polymer component (A) include acrylic resins, urethane resins, phenoxy resins, silicone resins, saturated polyester resins, etc., and acrylic resins are preferred.

[0063] Examples of the acrylic resin in the polymer component (A) include known acrylic polymers. The weight average molecular weight (Mw) of the acrylic resin is preferably from 10,000 to 2,000,000, more preferably from 100,000 to 1,500,000, still more preferably from 200,000 to 1,200,000, and particularly preferably from 300,000 to 1,000,000. When the weight average molecular weight of the acrylic resin is at least the lower limit value, it becomes easier to increase the E’(160) and E’(170). When the weight average molecular weight of the acrylic resin is at most the upper limit value, the protective film forming film can more easily follow the uneven surface of the adherend.

[0064] In this specification, the "weight average molecular weight" is the polystyrene conversion value measured by the gel permeation chromatography (GPC) method, unless otherwise specified.

[0065] The glass transition temperature (Tg) of the acrylic resin is preferably from -60 to 70°C, more preferably from -50 to 50°C, still more preferably from -50 to 20°C, and particularly preferably from -50 to -5°C. When the Tg of the acrylic resin is at least the lower limit value, for example, the adhesion between the cured 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 at most the upper limit value, the adhesive force between the protective film forming film and its cured product and the adherend is improved.

[0066] When the acrylic resin has m types (m is an integer of 2 or more) of structural units, and non-repeating numbers from 1 to m are sequentially assigned to the m types of monomers that induce these structural units and named "monomer m", the glass transition temperature (Tg) of the acrylic resin can be calculated using the following Fox's formula.

[0067] [Number] (In the formula, Tg is the glass transition temperature of the acrylic resin; m is an integer of 2 or more; Tg k is the glass transition temperature of the homopolymer of monomer m; W k is the mass fraction of the structural unit m derived from monomer m in the acrylic resin, provided that W k satisfies the following formula.)

[0068] [Number] (In the formula, m and W k are the same as those described above.)

[0069] As for the above Tg k , values described in a polymer data handbook, an adhesion handbook, Polymer Handbook, etc. can be used. For example, the Tg of the homopolymer of methyl acrylate k is 10°C, the Tg of the homopolymer of methyl methacrylate k is 105°C, the Tg of the homopolymer of 2-hydroxyethyl acrylate k is -15°C, the Tg of the homopolymer of glycidyl methacrylate k is 41°C, the Tg of the homopolymer of 2-ethylhexyl acrylate k is -70°C, the Tg of the homopolymer of acrylic acid k is 103°C, the Tg of the homopolymer of acrylonitrile k is 97°C, the Tg of the homopolymer of n-butyl acrylate k is -54°C, the Tg of the homopolymer of ethyl acrylate k is -24°C.

[0070] Examples of the acrylic resin include polymers of one or more (meth)acrylic acid esters; copolymers of two or more monomers selected from the group consisting of the (meth)acrylic acid esters, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like.

[0071] Examples of the (meth)acrylic acid ester that constitutes the acrylic resin include (meth)acrylic acid methyl, (meth)acrylic acid ethyl, (meth)acrylic acid n-propyl, (meth)acrylic acid isopropyl, (meth)acrylic acid n-butyl, (meth)acrylic acid isobutyl, (meth)acrylic acid sec-butyl, (meth)acrylic acid tert-butyl, (meth)acrylic acid pentyl, (meth)acrylic acid hexyl, (meth)acrylic acid heptyl, (meth)acrylic acid 2-ethylhexyl, (meth)acrylic acid isooctyl, (meth)acrylic acid n-octyl, (meth)acrylic acid n-nonyl, (meth)acrylic acid isononyl, (meth)acrylic acid decyl, (meth)acrylic acid undecyl, (meth)acrylic acid dodecyl ((meth)acrylic acid lauryl), (meth)acrylic acid tridecyl, (meth)acrylic acid tetradecyl ((meth)acrylic acid myristyl), (meth)acrylic acid pentadecyl, (meth)acrylic acid hexadecyl ((meth)acrylic acid palmityl), (meth)acrylic acid heptadecyl, (meth)acrylic acid octadecyl ((meth)acrylic acid stearyl), etc., wherein the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms, and (meth)acrylic acid alkyl esters; (meth)acrylic acid cycloalkyl esters such as (meth)acrylic acid isobornyl and (meth)acrylic acid dicyclopentanyl; (meth)acrylic acid aralkyl esters such as (meth)acrylic acid benzyl; (meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester; (meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyl oxyethyl ester; (meth)acrylic acid imide; (Meth)acrylic acid glycidyl esters such as glycidyl (meth)acrylate; Hydroxyl group-containing (meth)acrylic acid esters such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate; Examples thereof include substituted amino group-containing (meth)acrylic acid esters such as N-methylaminoethyl (meth)acrylate. Here, the "substituted amino group" means a group having a structure in which one or two hydrogen atoms of the amino group are substituted with groups other than hydrogen atoms.

[0072] In this specification, "(meth)acrylic acid" is a concept that includes 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 includes both "acryloyl group" and "methacryloyl group", and "(meth)acrylate" is a concept that includes both "acrylate" and "methacrylate".

[0073] The monomer constituting the acrylic resin may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0074] The acrylic resin may have a functional group capable of bonding to other compounds such as a vinyl group, (meth)acryloyl group, amino group, hydroxyl group, carboxyl group, isocyanate group. The functional group of the acrylic resin may be bonded to other compounds via a crosslinking agent (F) described later, or may be directly bonded to other compounds without passing through the crosslinking agent (F).

[0075] An example of a preferred acrylic resin is an acrylic resin (α) that has a structural unit derived from a (meth)acrylic acid alkyl ester and further has either or both of a structural unit derived from acrylonitrile and a structural unit derived from acrylic acid.

[0076] In the acrylic resin (α), the proportion (content) of the total amount of the structural units derived from acrylonitrile and the structural units derived from acrylic acid relative to the total amount of structural units constituting the acrylic resin (α) is preferably 0.5 to 50 mass%, and may be, for example, any one of 0.5 to 18 mass%, 0.5 to 11 mass%, and 0.5 to 4 mass%, or any one of 18 to 45 mass%, and 20 to 40 mass%.

[0077] In the acrylic resin (α), the proportion (content) of the amount of the structural units derived from the (meth)acrylic acid ester relative to the total amount of structural units constituting the acrylic resin (α) is preferably 50 to 99.5 mass%, and may be, for example, either 50 to 82 mass% or 82 to 99.5 mass%.

[0078] In the present invention, as the polymer component (A), a thermoplastic resin other than an acrylic resin (hereinafter sometimes simply referred to as a "thermoplastic resin") may be used alone without using an acrylic resin, or may be used in combination with an acrylic resin. Use of 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.

[0079] The weight average molecular weight of the thermoplastic resin is preferably 1,000 to 100,000, and more preferably 3,000 to 80,000.

[0080] The glass transition temperature (Tg) of the thermoplastic resin is preferably from -30 to 150°C, more preferably from -20 to 120°C.

[0081] Examples of the thermoplastic resin include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, polystyrene, and the like.

[0082] The thermoplastic resin contained in the composition (III) and the protective film-forming film may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0083] In the composition (III), the ratio of the content of the 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 the polymer component (A). For example, it may be either 15 to 45% by mass or 15 to 35% by mass, or it may be either 20 to 70% by mass or 25 to 70% by mass. This is synonymous with the fact that in the protective film-forming film, the ratio of the content of the polymer component (A) 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 the polymer component (A). For example, it may be either 15 to 45% by mass or 15 to 35% by mass, or it may be either 20 to 70% by mass or 25 to 70% by mass. This is based on the fact that in the process of removing the solvent from the resin composition containing the solvent to form a resin film, the amount of components other than the solvent usually does not change, and the ratio of the contents of components other than the solvent is the same between the resin composition and the resin film. Therefore, in this specification, hereinafter, regarding the content of components other than the solvent, only the content in the resin film obtained by removing the solvent from the resin composition is described, not limited to the case of the protective film-forming film.

[0084] The polymer component (A) may also correspond to the thermosetting component (B). In the present invention, when the composition (III) contains a component that corresponds to both such a polymer component (A) and a thermosetting component (B), the composition (III) is regarded as containing the polymer component (A) and the thermosetting component (B).

[0085] [Thermosetting component (B)] The thermosetting component (B) is a component for curing the protective film-forming film. The thermosetting component (B) contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0086] 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, the thermosetting polyimide resin is a general term for a polyimide precursor that forms a polyimide resin by thermal curing, and a thermosetting polyimide.

[0087] (epoxy thermosetting resin) The epoxy thermosetting resin is composed of an epoxy resin (B1) and a thermosetting agent (B2). The epoxy thermosetting resin contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0088] Epoxy resin (B1) Examples of the epoxy resin (B1) include known epoxy resins, such as bifunctional or higher functional epoxy compounds, including polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene-type epoxy resins, biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and phenylene skeleton-type epoxy resins.

[0089] As the epoxy resin (B1), an epoxy resin having an unsaturated hydrocarbon group may be used.

[0090] The number average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoints of the curability of the protective film-forming film and the strength and heat resistance of the protective film, it is preferably 300 to 30,000, more preferably 300 to 10,000, and particularly preferably 300 to 3,000. The epoxy equivalent of the epoxy resin (B1) is preferably 100 to 1000 g / eq, and more preferably 150 to 950 g / eq.

[0091] The epoxy resin (B1) may be used alone or in combination of two or more. When two or more are used in combination, their combinations and ratios can be arbitrarily selected.

[0092] ·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 an epoxy group in one molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxy group, a group in which an acid group is anhydrified, etc., and it is preferably a phenolic hydroxyl group, an amino group, or a group in which an acid group is anhydrified, and more preferably a phenolic hydroxyl group or an amino group.

[0093] Among the thermosetting agents (B2), examples of the phenolic curing agent having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenol, novolak-type phenolic resins, dicyclopentadiene-type phenolic resins, aralkyl-type phenolic resins, etc. Among the thermosetting agents (B2), examples of the amine curing agent having an amino group include dicyandiamide, etc.

[0094] The thermosetting agent (B2) may have an unsaturated hydrocarbon group.

[0095] When a phenol-based curing agent is used as the heat curing agent (B2), it is preferable that the heat curing agent (B2) has a high softening point or glass transition temperature, since this improves the peelability of the protective film from the support sheet.

[0096] Of the thermosetting agents (B2), for example, the number average molecular weight of resin components such as polyfunctional phenol resins, novolac type phenol resins, dicyclopentadiene type phenol resins, and aralkyl type phenol resins is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000. Of the thermosetting agent (B2), the molecular weight of the non-resin components such as biphenol and dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

[0097] The heat curing agent (B2) may be used alone or in combination of two or more kinds. When two or more kinds are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0098] In the composition (III) and the protective film-forming film, the content of the heat curing agent (B2) is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, and may be, for example, any of 0.5 to 25 parts by mass, 0.5 to 10 parts by mass, and 0.5 to 5 parts by mass, relative to 100 parts by mass of the epoxy resin (B1). When the content of the heat curing agent (B2) is equal to or more than the lower limit, the curing of the protective film-forming film is more likely to proceed. When the content of the heat curing agent (B2) is equal to or less than the upper limit, the moisture absorption rate of the protective film-forming film is reduced, and the reliability of the package obtained using the protective film-forming film is further improved.

[0099] In the composition (III) and the protective film-forming film, the content of the thermosetting component (B) (for example, the total content of the epoxy resin (B1) and the thermosetting agent (B2)) is preferably 10 to 70 parts by mass, more preferably 20 to 60 parts by mass, still more preferably 25 to 50 parts by mass, and particularly preferably 30 to 45 parts by mass with respect to 100 parts by mass of the total content of the polymer component (A) and the thermosetting component (B). When the content of the thermosetting component (B) is within such a range, for example, the adhesion between the cured product of the protective film-forming film and the support sheet is suppressed, and the peelability of the support sheet is improved.

[0100] [Filler (D)] The composition (III) and the protective film-forming film preferably contain a filler (D). By the protective film-forming film containing the filler (D), the storage elastic modulus E' of the test piece can be more easily adjusted. More specifically, by adjusting the average particle diameter of the filler (D) contained in the protective film-forming film and the content of the filler (D) in the protective film-forming film, the storage elastic modulus E' of the test piece can be more easily adjusted. Further, by the protective film-forming film containing the filler (D), the adjustment of the coefficient of thermal expansion of the protective film-forming film and the protective film becomes easy, and by optimizing this coefficient of thermal expansion with respect to the object to be formed with the protective film, the reliability of the chip with the protective film obtained using the protective film-forming film is further improved. Further, by the protective film-forming film containing the filler (D), the moisture absorption rate of the protective film can be reduced or the heat dissipation property can be improved.

[0101] The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler. Preferred inorganic fillers include, for example, powders such as silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride; beads obtained by spheroidizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers and the like. Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

[0102] In terms of improving the dispersibility of the filler (D) in the composition for forming a protective film with respect to other components, the silica is preferably silica surface-modified with an organic group, more preferably silica surface-modified with a vinyl group, an epoxy group, a phenyl group or a methacrylic group, and particularly preferably silica surface-modified with a vinyl group or an epoxy group.

[0103] In terms of improving the dispersibility of the filler (D) in the composition for forming a protective film with respect to other components, the average particle diameter of the filler (D) is preferably 0.02 to 2 μm, more preferably 0.05 to 0.7 μm, and particularly preferably 0.07 to 0.5 μm. When the average particle diameter of the filler (D) is not more than the above upper limit value, the E’(160) and E’(170) tend to be larger.

[0104] The filler (D) contained in the composition (III) and the protective film-forming film may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0105] When using the filler (D), the ratio of the content of the filler (D) to the total mass of the protective film-forming film in the protective film-forming film is preferably 15 to 70% by mass, for example, any one of 40 to 70% by mass, 45 to 70% by mass, and 50 to 70% by mass, or may be 15 to 60% by mass. When the ratio is within such a range, the adjustment of the storage elastic modulus E’ of the test piece and the adjustment of the thermal expansion coefficients of the protective film-forming film and the protective film become easier.

[0106] [Curing accelerator (C)] The composition (III) and the protective film-forming film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of the composition (III). Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organic phosphines such as tributylphosphine, diphenylphosphine, triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

[0107] The curing accelerator (C) contained in the composition (III) and the protective film-forming film may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0108] When using the curing accelerator (C), in the composition (III) and the protective film-forming film, the content of the curing accelerator (C) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 7 parts by mass, based on 100 parts by mass of the content of the thermosetting component (B). When the content of the curing accelerator (C) is at or above the lower limit value, the effect of using the curing accelerator (C) can be obtained more significantly. When the content of the curing accelerator (C) is at or below the upper limit value, for example, the effect of suppressing the migration and segregation of a highly polar curing accelerator (C) to the adhesion interface side with the adherend in the protective film-forming film under high temperature and high humidity conditions is enhanced. As a result, the reliability of the chip with the protective film obtained using the protective film-forming film is further improved.

[0109] [Coupling agent (E)] The composition (III) and the protective film-forming film may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesiveness of the protective film formed from the protective film-forming film to the adherend can be improved. Further, by using the coupling agent (E), the protective film has improved water resistance without impairing its heat resistance.

[0110] The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional groups of the polymer component (A), the thermosetting component (B), etc., and more preferably a silane coupling agent.

[0111] Examples of the preferred silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole silane, and the like.

[0112] Examples of the preferred silane coupling agent also include oligomer-type silane coupling agents having a plurality of alkoxysilyl groups in one molecule. Since the oligomeric silane coupling agent is difficult to volatilize and has a plurality of alkoxysilyl groups in one molecule, it is preferable in that it is effective in improving durability. Examples of the oligomeric silane coupling agent include "X-41-1053", "X-41-1059A", "X-41-1056", and "X-40-2651" (all manufactured by Shin-Etsu Chemical Co., Ltd.), which are epoxy group-containing oligomeric silane coupling agents; "X-41-1818", "X-41-1810", and "X-41-1805" (all manufactured by Shin-Etsu Chemical Co., Ltd.), which are mercapto group-containing oligomeric silane coupling agents, and the like.

[0113] The coupling agent (E) contained in the composition (III) and the protective film-forming film may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0114] When the coupling agent (E) is used, in the composition (III) and the protective film-forming film, the content of the coupling agent (E) 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 with respect to 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 within such a range, the chemical compatibility between the protective film-forming film and the adherend can be slightly controlled, and the adhesiveness and peelability can be more easily adjusted. On the other hand, when the content of the coupling agent (E) is equal to or higher than the lower limit value, the effects obtained by using the coupling agent (E), such as the improvement of the dispersibility of the filler (D) in the resin and the improvement of the adhesiveness between the protective film-forming film and the adherend, can be obtained more significantly. When the content of the coupling agent (E) is equal to or lower than the upper limit value, the generation of outgas is more suppressed.

[0115] [Crosslinking agent (F)] When using, as the polymer component (A), those having functional groups such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, isocyanate groups, etc., which can be bonded to other compounds, such as the above-mentioned acrylic resins, the composition (III) and the protective film-forming film may contain a crosslinking agent (F). The crosslinking agent (F) is a component for bonding the functional groups in the polymer component (A) to other compounds for crosslinking. By crosslinking in this way, the adhesive force and cohesive force of the protective film-forming film can be adjusted.

[0116] Examples of the crosslinking agent (F) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate-based crosslinking agents (crosslinking agents having a metal chelate structure), aziridine-based crosslinking agents (crosslinking agents having an aziridinyl group), and the like.

[0117] The crosslinking agent (F) contained in the composition (III) and the protective film-forming film may be only one kind, or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0118] In terms of improving the temporal stability of the composition for forming a protective film, it is preferable that the composition (III) does not contain the crosslinking agent (F), or in the composition (III), the content of the crosslinking agent (F) is, for example, less than 0.01 part by mass with respect to 100 parts by mass of the content of the polymer component (A), that is, the content of the crosslinking agent (F) is small. On the other hand, when using a certain amount or more of the crosslinking agent (F), in the composition (III), the content of the crosslinking agent (F) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the content of the polymer component (A). When the content of the crosslinking agent (F) is not less than the lower limit value, the effect of using the crosslinking agent (F) can be obtained more significantly. When the content of the crosslinking agent (F) is not more than the upper limit value, excessive use of the crosslinking agent (F) is suppressed.

[0119] [Energy ray-curable resin (G)] The composition (III) and the protective film-forming film may contain an energy-ray curable resin (G). By containing the energy-ray curable resin (G), the protective film-forming film can change its properties by irradiation with energy rays.

[0120] The energy-ray curable resin (G) is an energy-ray curable compound, or an oligomer or polymer (polymer) that can be regarded as 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.

[0121] Examples of the acrylate compounds include chain aliphatic skeleton-containing (meth)acrylates such as trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxy penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate; 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)acrylate; urethane (meth)acrylate oligomer; epoxy-modified (meth)acrylate; polyether (meth)acrylate other than the polyalkylene glycol (meth)acrylate; itaconic acid oligomer, and the like.

[0122] The weight average molecular weight of the energy-ray curable compound is preferably from 100 to 30,000, more preferably from 300 to 10,000.

[0123] The energy ray-curable compound used in the synthesis of the oligomer or polymer may be one kind or two or more kinds, and when two or more kinds are used, the combination and ratio thereof can be selected arbitrarily.

[0124] The energy ray curable resin (G) contained in the composition (III) and the protective film-forming film may be one type or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0125] When the energy ray curable resin (G) is used, the content of the energy ray curable resin (G) in the composition (III) relative to the total mass of the composition (III) is preferably 1 to 30 mass%, more preferably 5 to 25 mass%, and particularly preferably 10 to 20 mass%.

[0126] [Photopolymerization initiator (H)] When the composition (III) and the protective film-forming film contain an energy ray curable resin (G), they may contain a photopolymerization initiator (H) in order to efficiently advance the polymerization reaction of the energy ray curable resin (G).

[0127] Examples of the photopolymerization initiator (H) in the composition (III) include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin 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; acylphosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; sulfide compounds such as benzyl phenyl sulfide and tetramethylthiuram monosulfide; α-ketol compounds such as 1-hydroxycyclohexyl phenyl ketone; azo compounds such as azobisisobutyronitrile; titanocene compounds such as titanocene; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as diacetyl; benzyl; dibenzyl; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; and quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone. In addition, examples of the photopolymerization initiator (H) also include photosensitizers such as amines.

[0128] The photopolymerization initiator (H) contained in the composition (III) and the protective film-forming film may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0129] When using the photoinitiator (H), in the composition (III), the content of the photoinitiator (H) 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 with respect to 100 parts by mass of the energy ray curable resin (G).

[0130] [Colorant (I)] The composition (III) and the protective film forming film preferably contain a colorant (I). By containing the colorant (I), the light transmittance of the protective film forming film and the protective film can be easily adjusted.

[0131] Examples of the colorant (I) include known ones such as inorganic pigments, organic pigments, and organic dyes.

[0132] Examples of the organic pigments and organic dyes include ammonium-based dyes, cyanine-based dyes, merocyanine-based dyes, croconium-based dyes, squarium-based dyes, azulenium-based dyes, polymethine-based dyes, naphthoquinone-based dyes, pyrylium-based dyes, phthalocyanine-based dyes, naphthalocyanine-based dyes, naphtholactam-based dyes, azo-based dyes, condensed azo-based dyes, indigo-based dyes, perinone-based dyes, perylene-based dyes, dioxazine-based dyes, quinacridone-based dyes, isoindolinone-based dyes, quinophthalone-based dyes, pyrrole-based dyes, thioindigo-based dyes, metal complex-based dyes (metal complex salts), dithiol metal complex-based dyes, indole phenol-based dyes, triallylmethane-based dyes, anthraquinone-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyranthrone-based dyes, and threne-based dyes.

[0133] Examples of the inorganic pigments 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.

[0134] The colorant (I) contained in the composition (III) and the protective film-forming film may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0135] When using the colorant (I), the content of the colorant (I) in the protective film-forming film may be appropriately adjusted according to the purpose. For example, by adjusting the content of the colorant (I) in the protective film-forming film and adjusting the light transmittance of the protective film-forming film, the print visibility when laser printing is performed on the protective film-forming film or the protective film can be adjusted. Also, by adjusting the content of the colorant (I) in the protective film-forming film, the design property of the protective film can be improved, or the grinding marks on the back surface of the wafer can be made less visible. Considering these points, the ratio of the content of the colorant (I) to the total mass of the protective film-forming film in 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 at least the lower limit value, the effect of using the colorant (I) can be obtained more significantly. For example, when the protective film-forming film is peeled from the adherend, the presence or absence of residue of the protective film-forming film on the adherend can be easily confirmed visually. When the ratio is at most the upper limit value, excessive use of the colorant (I) is suppressed.

[0136] [General-purpose additive (J)] The 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 a known one, can be arbitrarily selected according to the purpose, and is not particularly limited. Preferred examples include plasticizers, antistatic agents, antioxidants, gettering agents, ultraviolet absorbers, and the like.

[0137] The general-purpose additive (J) contained in the composition (III) and the protective film-forming film may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected. The content of the composition (III) and the general-purpose additive (J) of the protective film-forming film is not particularly limited and may be appropriately selected according to the purpose.

[0138] [Solvent] The composition (III) preferably further contains a solvent. The composition (III) containing a solvent has good handleability. In this specification, unless otherwise specified, the term "solvent" is a concept that includes not only a substance that dissolves the target component but also a dispersion medium that disperses the target component.

[0139] 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; amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The composition (III) may contain only one kind of solvent or two or more kinds of solvents. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0140] Among the solvents contained in the composition (III), more preferred examples include methyl ethyl ketone, toluene, ethyl acetate, etc. from the viewpoint of being able to mix the components contained in the composition (III) more uniformly.

[0141] The content of the solvent in the composition (III) is not particularly limited and may be appropriately selected according to, for example, the types of components other than the solvent.

[0142] <Method for producing the protective film-forming composition (III)> The composition (III) can be obtained by blending each component for constituting it. The addition order at the time of blending each component is not particularly limited, and two or more components may be added simultaneously. The method of mixing the respective components during compounding is not particularly limited, and any known method can be appropriately selected, such as a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer; a method of mixing by applying ultrasonic waves, etc. The temperature and time during the addition and mixing of each component are not particularly limited as long as each compounding component does not deteriorate, and can be adjusted as appropriate. However, the temperature is preferably 15 to 30°C.

[0143] ◎ Examples of the protective film-forming film FIG. 1 is a cross-sectional view schematically showing an example of the protective film-forming film of the present embodiment. In addition, the figures used in the following description may show the main part enlarged for the sake of easy understanding of the features of the present invention, and the dimensional ratios of each component are not necessarily the same as the actual ones.

[0144] The protective film-forming film 13 shown here has a first release film 151 on one of its surfaces (which may be referred to as the "first surface" in this specification) 13a, and a second release film 152 on the other surface (which may be referred to as the "second surface" in this specification) 13b opposite to the first surface 13a. Such a protective film-forming film 13 is suitable for storage in a roll shape, for example.

[0145] When the storage elastic modulus E' of the test piece produced using the protective film-forming film 13 is measured, the storage elastic modulus E' of the test piece is 1 MPa or more in all temperature ranges from 160°C to 170°C.

[0146] The protective film-forming film 13 can be formed using the above-described composition for forming a protective film.

[0147] Both the first release film 151 and the second release film 152 may be known ones. The first release film 151 and the second release film 152 may be the same as each other, or may be different from each other, for example, when the release forces required for peeling from the protective film-forming film 13 are different from each other.

[0148] Of the first release film 151 and the second release film 152 of the protective film forming film 13 shown in FIG. 1, one is removed, and the resulting exposed surface becomes the attachment surface to any part of the work (not shown). When using the support sheet or dicing sheet described later, the remaining one 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 attachment surface of the support sheet or dicing sheet.

[0149] FIG. 1 shows an example in which release films are provided on both surfaces (the first surface 13a and the second surface 13b) of the protective film forming film 13, but the release film may be provided on only one surface of the protective film forming film 13, that is, only on the first surface 13a or only on the second surface 13b.

[0150] By using the protective film forming film of the present embodiment in combination with the support sheet described later, it is possible to configure a composite sheet for forming a protective film that can perform both the formation of the protective film and dicing. Hereinafter, such a composite sheet for forming a protective film will be described.

[0151] ◇Composite sheet for forming protective film A composite sheet for forming a protective film according to an embodiment of the present invention includes a support sheet and a protective film forming film provided on one surface of the support sheet, and the protective film forming film is the protective film forming film according to an embodiment of the present invention described above. The composite sheet for forming a protective film of the present embodiment can be attached to a target part (for example, the back surface of a wafer) of the work by the protective film forming film therein.

[0152] In this specification, as long as the laminated structure of the support sheet and the cured product of the protective film forming film is maintained even after the protective film forming film is cured, this laminated structure is referred to as a "composite sheet for forming a protective film".

[0153] Hereinafter, each layer constituting the composite sheet for forming the protective film will be described in detail.

[0154] ◎ Support sheet The support sheet may be composed of one layer (single layer) or may be composed of two or more layers. When the support sheet is composed of a plurality of layers, the constituent materials and thicknesses of these plurality of layers may be the same as or different from each other, and the combination of these plurality of layers is not particularly limited as long as the effects of the present invention are not impaired.

[0155] The support sheet may be either transparent or non-transparent, and may be colored according to the purpose. When the protective film forming film has energy ray curability, it is preferable that the support sheet transmits energy rays.

[0156] Examples of the support sheet include those provided with a base material and an adhesive layer provided on one surface of the base material; those composed only of the base material; and the like. When the support sheet has an adhesive layer, the adhesive layer is disposed between the base material and the protective film forming film in the composite sheet for forming the protective film.

[0157] When a support sheet provided with a base material and an adhesive layer is used, the adhesion and peelability between the support sheet and the protective film forming film in the composite sheet for forming the protective film can be easily adjusted. When a support sheet composed only of the base material is used, the composite sheet for forming the protective film can be manufactured at low cost.

[0158] Examples of the composite sheet for forming the protective film of the present embodiment will be described below for each type of such support sheet with reference to the drawings.

[0159] ◎ An example of the composite sheet for forming the protective film FIG. 2 is a cross-sectional view schematically showing an example of the composite sheet for forming the protective film of the present embodiment. In the figures after Fig. 2, the same components as those shown in the already described figures are given the same reference numerals as in the case of the already described figures, and the detailed description thereof is omitted.

[0160] The composite sheet 101 for forming a protective film shown here is composed of a support sheet 10 and a protective film forming film 13 provided on one surface (which may be referred to as the "first surface" in this specification) 10a of the support sheet 10. The support sheet 10 is composed of a base material 11 and an adhesive layer 12 provided on one surface (the first surface) 11a of the base material 11. In the composite sheet 101 for forming a protective film, the adhesive layer 12 is disposed between the base material 11 and the protective film forming film 13. That is, the composite sheet 101 for forming a protective film is configured by laminating the base material 11, the adhesive layer 12, and the protective film forming film 13 in this order in their thickness directions. The first surface 10a of the support sheet 10 is the same as the surface (which may be referred to as the "first surface" in this specification) 12a on the side of the base material 11 of the adhesive layer 12 and opposite thereto.

[0161] The composite sheet 101 for forming a protective film further includes a jig adhesive layer 16 and a release film 15 on the protective film forming film 13. In the composite sheet 101 for forming a protective film, the protective film forming film 13 is laminated on the entire or substantially the entire first surface 12a of the adhesive layer 12, and a jig adhesive layer 16 is laminated on a part of the surface (which may be referred to as the "first surface" in this specification) 13a on the side opposite to the adhesive layer 12 side of the protective film forming film 13, that is, in the region near the peripheral edge. Further, a release film 15 is laminated on the region 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 (which may be referred to as the "first surface" in this specification) 16a on the side opposite to the protective film forming film 13 side of the jig adhesive layer 16. A support sheet 10 is provided on the surface (which may be referred to as the "second surface" in this specification) 13b on the side opposite to the first surface 13a of the protective film forming film 13.

[0162] Not limited to the case of the composite sheet 101 for forming a protective film, in the composite sheet for forming a protective film of the present embodiment, the release film (for example, the release film 15 shown in FIG. 2) has an arbitrary configuration, and the composite sheet for forming a protective film of the present embodiment may or may not include a release film.

[0163] The jig adhesive layer 16 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 have, for example, a single-layer structure containing an adhesive component or an adhesive component, or may have a multi-layer structure including a sheet serving as a core material and layers provided on both surfaces of the sheet and containing an adhesive component or an adhesive component.

[0164] The composite sheet 101 for forming a protective film is used by attaching the target portion of the workpiece to the first surface 13a of the protective film forming film 13 in a state where the release film 15 is removed, and further attaching the first surface 16a of the jig adhesive layer 16 to a jig such as a ring frame.

[0165] As described above, when manufacturing the workpiece with a protective film using the protective film forming film 13, even if the protective film forming film 13 is thermally cured at a higher temperature than before, the occurrence of abnormalities in the protective film can be suppressed.

[0166] FIG. 3 is a cross-sectional view schematically showing another example of the composite sheet for forming a protective film of the present embodiment. The composite sheet 102 for forming a protective film shown here is the same as the composite sheet 101 for forming a protective film shown in FIG. 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.

[0167] More specifically, in the composite sheet 102 for forming a protective film, the protective film forming film 23 is laminated on a partial region of the first surface 12a of the adhesive layer 12, that is, on the central region in the width direction (the left - right direction in FIG. 3) of the adhesive layer 12. Further, on the region of the first surface 12a of the adhesive layer 12 where the protective film forming film 23 is not laminated, a jig - use adhesive layer 16 is laminated so as to non - contactingly surround the protective film forming film 23 from the outside in its width direction. And a release film 15 is laminated on the surface 23a (which may be referred to as the "first surface" in this specification) on the side opposite to the adhesive layer 12 side of the protective film forming film 23 and the first surface 16a of the jig - use adhesive layer 16. A support sheet 10 is provided on the surface 23b (which may be referred to as the "second surface" in this specification) on the side opposite to the first surface 23a of the protective film forming film 23.

[0168] FIG. 4 is a cross - sectional view schematically showing still another example of the composite sheet for forming a protective film of the present embodiment. The composite sheet 103 for forming a protective film shown here is the same as the composite sheet 102 for forming a protective film shown in FIG. 3, except that it does not include the jig - use adhesive layer 16.

[0169] FIG. 5 is a cross - sectional view schematically showing still another example of the composite sheet for forming a protective film of the present embodiment. The composite sheet 104 for forming a protective film shown here is the same as the composite sheet 101 for forming a protective film shown in FIG. 2, except that it is configured to include a support sheet 20 instead of the support sheet 10.

[0170] The support sheet 20 is composed of only the base material 11. That is, the composite sheet 104 for forming a protective film is configured by laminating the base material 11 and the protective film forming film 13 in their thickness directions. The surface 20a (one surface) on the protective film forming film 13 side of the support sheet 20 is the same as the first surface 11a of the base material 11.

[0171] The composite sheet for forming a protective film according to this embodiment is not limited to those shown in FIGS. 1 to 5, and within the range not impairing the effects of the present invention, a part of the configuration of those shown in FIGS. 1 to 5 may be changed or deleted, or other configurations may be added to those described so far.

[0172] Next, each layer constituting the support sheet will be described in more detail.

[0173] ○Base material The base material is in the form of a sheet or film, and examples of its constituent materials include various resins. Examples of the resin include polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-based copolymers (copolymers obtained using ethylene as a monomer) such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer, and ethylene-norbornene copolymer; vinyl chloride-based resins (resins obtained using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymer; polystyrene; polycycloolefin; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalene dicarboxylate, and wholly aromatic polyester in which all constitutional units have an aromatic cyclic group; copolymers of two or more of the above polyesters; poly(meth)acrylate; polyurethane; polyurethane acrylate; polyimide; polyamide; polycarbonate; fluororesin; polyacetal; modified polyphenylene oxide; polyphenylene sulfide; polysulfone; polyether ketone, etc. In addition, examples of the resin include polymer alloys such as a mixture of the above polyester and other resins. The polymer alloy of the polyester and other resins preferably has a relatively small amount of resin other than the polyester. In addition, examples of the resin include a crosslinked resin 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. In terms of excellent heat resistance, the resin is preferably polypropylene or polybutylene terephthalate.

[0174] The resin constituting the base material may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0175] The base material may be composed of one layer (single layer) or may be composed of two or more layers. When it is composed of two or more layers, these layers may be the same as or different from each other, and the combination of these layers is not particularly limited.

[0176] The thickness of the base material is preferably 50 to 300 μm, and more preferably 60 to 100 μm. When the thickness of the base material is within such a range, the flexibility of the composite sheet for forming a protective film and the adhesion suitability to the wafer are further improved. Here, the "thickness of the base material" means the thickness of the entire base material. For example, the thickness of a base material composed of multiple layers means the total thickness of all the layers constituting the base material.

[0177] In addition to the main constituent materials such as the resin, the base material may contain various known additives such as fillers, colorants, antioxidants, organic lubricants, catalysts, and softeners (plasticizers).

[0178] The base material may be either transparent or non-transparent, may be colored according to the purpose, or may have other layers deposited thereon. When the protective film-forming film has energy ray curability, the base material preferably transmits energy rays.

[0179] The substrate may be subjected to surface treatments such as roughening treatment by sandblasting, solvent treatment, etc. to adjust the adhesion to the layer provided thereon (e.g., an adhesive layer, a protective film-forming film, or the other layer); oxidation treatment such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone-ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment, etc.; lipophilic treatment; hydrophilic treatment, etc. Further, the surface of the substrate may be primer-treated.

[0180] The substrate may have adhesiveness on at least one surface by containing components within a specific range (e.g., resin, etc.).

[0181] 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.

[0182] ○Adhesive layer The adhesive layer is in the form of a sheet or film and contains an adhesive. Examples of the adhesive include adhesive resins such as acrylic resins, urethane resins, rubber-based resins, silicone resins, epoxy resins, polyvinyl ethers, polycarbonates, ester-based resins, etc.

[0183] The adhesive layer may consist of one layer (single layer) or may consist of two or more layers. In the case of multiple layers, these multiple layers may be the same as or different from each other, and the combination of these multiple layers is not particularly limited.

[0184] 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, the "thickness of the adhesive layer" means the total thickness of the entire adhesive layer. For example, the thickness of an adhesive layer composed of multiple layers means the total thickness of all the layers constituting the adhesive layer.

[0185] The adhesive layer may be either transparent or non-transparent, and may be colored according to the purpose. When the protective film forming film has energy ray curability, it is preferable that the adhesive layer transmits energy rays.

[0186] The adhesive layer may be either energy ray curable or non-energy ray curable. The energy ray curable adhesive layer can adjust the physical properties before and after its curing. For example, by curing the energy ray curable adhesive layer before picking up the chip with a protective film described later, the chip with a protective film can be picked up more easily.

[0187] In this specification, as long as the laminated structure of the base material and the cured product of the energy ray curable adhesive layer is maintained even after the energy ray curable adhesive layer is cured by energy rays, this laminated structure is referred to as a "support sheet".

[0188] The adhesive layer can be formed using an adhesive composition containing an adhesive. For example, by applying the adhesive composition to the surface to be formed with the adhesive layer and drying it as necessary, the adhesive layer can be formed at the target site. The ratio of the contents of the components that do not vaporize at room temperature in the adhesive composition is usually the same as the ratio of the contents of the said components in the adhesive layer.

[0189] The application and drying of the adhesive composition can be carried out, for example, in the same manner as in the case of the application and drying of the above-described composition for forming a protective film.

[0190] When the adhesive layer is energy ray curable, examples of the energy ray curable adhesive composition include an adhesive composition (I-1) containing a non-energy ray curable pressure-sensitive adhesive resin (I-1a) (hereinafter, may be abbreviated as "pressure-sensitive adhesive resin (I-1a)") and an energy ray curable compound; an adhesive composition (I-2) containing an energy ray curable pressure-sensitive adhesive resin (I-2a) (hereinafter, may be abbreviated as "pressure-sensitive adhesive resin (I-2a)") in which an unsaturated group is introduced into the side chain of the non-energy ray curable pressure-sensitive adhesive resin (I-1a); an adhesive composition (I-3) containing the pressure-sensitive adhesive resin (I-2a) and an energy ray curable compound, and the like.

[0191] When the adhesive layer is non-energy ray curable, examples of the non-energy ray curable adhesive composition include an adhesive composition (I-4) containing the non-energy ray curable pressure-sensitive adhesive resin (I-1a), and the like.

[0192] [Non-energy ray curable pressure-sensitive adhesive resin (I-1a)] The pressure-sensitive adhesive resin (I-1a) is preferably an acrylic resin.

[0193] Examples of the acrylic resin include an acrylic polymer having at least a structural unit derived from an alkyl (meth)acrylate. Examples of the alkyl (meth)acrylate 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.

[0194] The acrylic polymer preferably further has a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the alkyl (meth)acrylate. Examples of the functional group-containing monomer include those in which the functional group reacts with a crosslinking agent described later to serve as a starting point for crosslinking.

[0195] Examples of the functional group-containing monomer include a hydroxyl group-containing monomer, a carboxy group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, and the like.

[0196] In addition to the structural unit derived from the (meth)acrylic acid alkyl ester and the structural unit derived from the functional group-containing monomer, the acrylic polymer may further have a structural unit derived from another monomer. The other monomer is not particularly limited as long as it is copolymerizable with a (meth)acrylic acid alkyl ester or the like. Examples of the other monomer include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide, and the like.

[0197] In the pressure-sensitive adhesive compositions (I-1), (I-2), (I-3), and (I-4) (hereinafter, these pressure-sensitive adhesive compositions are collectively abbreviated as "pressure-sensitive adhesive compositions (I-1) to (I-4)"), the structural units of the acrylic resin such as the acrylic polymer may be only one type or two or more types. When there are two or more types, their combinations and ratios can be arbitrarily selected.

[0198] In the acrylic polymer, the ratio of the amount of the structural unit derived from the functional group-containing monomer to the total amount of the structural units is preferably 1 to 35% by mass.

[0199] The pressure-sensitive adhesive resin (I-1a) contained in the pressure-sensitive adhesive composition (I-1) or the pressure-sensitive adhesive composition (I-4) may be only one type or two or more types. When there are two or more types, their combinations and ratios can be arbitrarily selected.

[0200] In the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (I-1) or the pressure-sensitive adhesive composition (I-4), the ratio of the content of the pressure-sensitive adhesive resin (I-1a) to the total mass of the pressure-sensitive adhesive layer is preferably 5 to 99% by mass.

[0201] [Energy ray curable pressure-sensitive adhesive resin (I-2a)] The pressure-sensitive adhesive resin (I-2a) can be obtained, for example, by reacting a functional group in the pressure-sensitive adhesive resin (I-1a) with an unsaturated group-containing compound having an energy ray polymerizable unsaturated group.

[0202] The unsaturated group-containing compound is a compound having a group capable of bonding to the pressure-sensitive adhesive resin (I-1a) by reacting with a functional group in the pressure-sensitive adhesive resin (I-1a) in addition to the energy ray polymerizable unsaturated group. Examples of the energy ray polymerizable unsaturated group include a (meth)acryloyl group, a vinyl group (ethenyl group), an allyl group (2-propenyl group), etc., and a (meth)acryloyl group is preferable. Examples of the group capable of bonding to a functional group in the pressure-sensitive adhesive resin (I-1a) include an isocyanate group and a glycidyl group capable of bonding to a hydroxyl group or an amino group, and a hydroxyl group and an amino group capable of bonding to a carboxy group or an epoxy group.

[0203] Examples of the unsaturated group-containing compound include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, glycidyl (meth)acrylate, etc.

[0204] The pressure-sensitive adhesive resin (I-2a) contained in the pressure-sensitive adhesive composition (I-2) or (I-3) may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0205] In the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (I-2) or (I-3), the proportion of the content of the pressure-sensitive adhesive resin (I-2a) with respect to the total mass of the pressure-sensitive adhesive layer is preferably 5 to 99% by mass.

[0206] [Energy ray curable compound] Examples of the energy ray curable compound contained in the pressure-sensitive adhesive composition (I-1) or (I-3) include monomers or oligomers having an energy ray polymerizable unsaturated group and curable by irradiation with energy rays.

[0207] Among the energy ray curable compounds, examples of the monomers 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, 1,6-hexanediol (meth)acrylate; urethane (meth)acrylate; polyester (meth)acrylate; polyether (meth)acrylate; epoxy (meth)acrylate and the like. Among the energy ray curable compounds, examples of the oligomers include oligomers which are polymers of the monomers exemplified above.

[0208] The energy ray curable compound contained in the pressure-sensitive adhesive composition (I-1) or (I-3) may be only one kind or two or more kinds. In the case of two or more kinds, their combinations and ratios can be arbitrarily selected.

[0209] In the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (I-1) or (I-3), the ratio of the content of the energy ray curable compound to the total mass of the pressure-sensitive adhesive layer is preferably 1 to 95% by mass.

[0210] [Crosslinking agent] When using the acrylic polymer having a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from an alkyl (meth)acrylate as the pressure-sensitive adhesive resin (I-1a), the pressure-sensitive adhesive composition (I-1) or (I-4) preferably further contains a crosslinking agent. Further, when using the acrylic polymer having a structural unit derived from a functional group-containing monomer similar to that in the pressure-sensitive adhesive resin (I-1a) as the pressure-sensitive adhesive resin (I-2a), the pressure-sensitive adhesive composition (I-2) or (I-3) may further contain a crosslinking agent.

[0211] The crosslinking agent reacts with the functional group to crosslink the pressure-sensitive adhesive resins (I-1a) or the pressure-sensitive adhesive resins (I-2a) with each other. Examples of the crosslinking agent include isocyanate-based crosslinking agents (crosslinking agents having isocyanate groups) such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy-based crosslinking agents (crosslinking agents having glycidyl groups) such as ethylene glycol glycidyl ether; aziridine-based crosslinking agents (crosslinking agents having aziridinyl groups) such as hexakis[1-(2-methyl)-aziridinyl]phosphorotriazine; metal chelate-based crosslinking agents (crosslinking agents having metal chelate structures) such as aluminum chelate; and isocyanurate-based crosslinking agents (crosslinking agents having an isocyanuric acid skeleton).

[0212] The crosslinking agent contained in the pressure-sensitive adhesive compositions (I-1) to (I-4) may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0213] In the pressure-sensitive adhesive composition (I-1) or (I-4), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass with respect to 100 parts by mass of the content of the pressure-sensitive adhesive resin (I-1a). In the pressure-sensitive adhesive composition (I-2) or (I-3), the content of the crosslinking agent is preferably 0.01 to 50 parts by mass with respect to 100 parts by mass of the content of the pressure-sensitive adhesive resin (I-2a).

[0214] [Photoinitiator] The pressure-sensitive adhesive compositions (I-1), (I-2), and (I-3) (hereinafter, collectively referred to as "pressure-sensitive adhesive compositions (I-1) to (I-3)") may further contain a photoinitiator. The pressure-sensitive adhesive compositions (I-1) to (I-3) containing a photoinitiator can proceed with a sufficient curing reaction even when irradiated with energy rays having relatively low energy such as ultraviolet rays.

[0215] Examples of the photoinitiator include those similar to the above-mentioned photoinitiator (H).

[0216] The photoinitiator contained in the pressure-sensitive adhesive compositions (I-1) to (I-3) may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0217] In the pressure-sensitive adhesive composition (I-1), the content of the photoinitiator is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the content of the energy ray-curable compound. In the pressure-sensitive adhesive composition (I-2), the content of the photoinitiator is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the content of the pressure-sensitive resin (I-2a). In the pressure-sensitive adhesive composition (I-3), the content of the photoinitiator is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the total content of the pressure-sensitive resin (I-2a) and the energy ray-curable compound.

[0218] [Other Additives] The pressure-sensitive adhesive compositions (I-1) to (I-4) may contain other additives that do not fall under any of the above components within the range that does not impair the effects of the present invention. Examples of the other additives include known additives such as antistatic agents, antioxidants, softeners (plasticizers), fillers, rust preventives, colorants (pigments, dyes), sensitizers, tackifiers, reaction retardants, crosslinking accelerators (catalysts), and the like. Note that the reaction retardant is a component that suppresses the progress of an unintended crosslinking reaction in the pressure-sensitive adhesive compositions (I-1) to (I-4) during storage by the action of a catalyst mixed in the pressure-sensitive adhesive compositions (I-1) to (I-4). Examples of the reaction retardant include those that form a chelate complex by a chelate with respect to the catalyst, and more specifically, those having two or more carbonyl groups (-C(=O)-) in one molecule.

[0219] The other additives contained in the pressure-sensitive adhesive compositions (I-1) to (I-4) may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0220] The content of the other additives in the pressure-sensitive adhesive compositions (I-1) to (I-4) is not particularly limited and may be appropriately selected according to the type thereof.

[0221] [Solvent] The pressure-sensitive adhesive compositions (I-1) to (I-4) may contain a solvent. By containing a solvent, the pressure-sensitive adhesive compositions (I-1) to (I-4) have improved coating suitability on the surface to be coated.

[0222] The solvent is preferably an organic solvent. Examples of the organic solvent include ketones such as methyl ethyl ketone and acetone; esters (carboxylic acid esters) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; and alcohols such as 1-propanol and 2-propanol.

[0223] The solvent contained in the pressure-sensitive adhesive compositions (I-1) to (I-4) may be only one kind or two or more kinds. When there are two or more kinds, their combinations and ratios can be arbitrarily selected.

[0224] The content of the solvent in the pressure-sensitive adhesive compositions (I-1) to (I-4) is not particularly limited and may be appropriately adjusted.

[0225] ○Method for producing pressure-sensitive adhesive composition The pressure-sensitive adhesive composition can be produced, for example, in the same manner as the composition for forming a protective film described above, except that the types of the compounding components are different.

[0226] ◇Method for producing composite sheet for forming protective film The composite sheet for forming the protective film can be manufactured by laminating the above-described respective layers so as to have the corresponding positional relationship, and adjusting the shape of part or all of the layers as necessary. The forming method of each layer is as described above.

[0227] For example, when manufacturing the support sheet, in the case of laminating the adhesive layer on the base material, the above-described adhesive composition may be applied on the base material and dried as necessary. Also, an adhesive layer can be formed on the release film by applying the adhesive composition on the release film and drying as necessary, and the exposed surface of this adhesive layer can be laminated on one surface of the base material by a method of bonding it. At this time, the adhesive composition is preferably applied to the release-treated surface of the release film. Further, in this case, the release film may be removed at any timing during the manufacturing process or the use process of the composite sheet for forming the protective film. So far, the case of laminating the adhesive layer on the base material has been taken as an example, but the above-described method can also be applied to the case of laminating other layers other than the adhesive layer on the base material, for example.

[0228] On the other hand, for example, when further laminating the protective film forming film on the adhesive layer laminated on the base material, it is possible to directly form the protective film forming film by applying the composition for forming the protective film on the adhesive layer. Layers other than the protective film forming film can also be laminated on the adhesive layer in the same manner using the composition for forming this layer. Thus, when forming a new layer (hereinafter abbreviated as "second layer") on any layer (hereinafter abbreviated as "first layer") laminated on the base material to form a continuous two-layer laminated structure (in other words, the laminated structure of the first layer and the second layer), a method of applying the composition for forming the second layer on the first layer and drying as necessary can be applied. However, the second layer is preferably formed in advance on the release film using a composition for forming the same, and a continuous two-layer laminated structure is formed by bonding the exposed surface of the formed second layer on the side opposite to the side in contact with the release film to the exposed surface of the first layer. At this time, the composition is preferably applied to the release-treated surface of the release film. The release film may be removed as necessary after the formation of the laminated structure. Here, the case where the protective film forming film is laminated on the adhesive layer has been described as an example. However, the target laminated structure can be arbitrarily selected, such as the case where a layer (film) other than the protective film forming film is laminated on the adhesive layer.

[0229] As described above, all the layers other than the base material constituting the composite sheet for forming the protective film can be formed in advance on the release film and laminated by a method of bonding them to the surface of the target layer. Therefore, the layers adopting such a process can be appropriately selected as necessary, and the composite sheet for forming the protective film can be manufactured.

[0230] The composite sheet for forming the protective film is usually stored in a state where the release film is bonded to the surface of the outermost layer (for example, the protective film forming film) on the side opposite to the support sheet. Therefore, a composition for forming a layer constituting the outermost layer, such as a composition for forming a protective film, is applied on this release film (preferably its release-treated surface) and dried as necessary to form a layer constituting the outermost layer on the release film. Then, the remaining layers are laminated on the exposed surface of this layer on the side opposite to the side in contact with the release film, and the release film is left in a bonded state without being removed, thereby obtaining a composite sheet for forming a protective film with a release film.

[0231] ◇ Method for manufacturing a workpiece with a protective film (method of using a protective film forming film and a composite sheet for forming a protective film) The protective film forming film and the composite sheet for forming a protective film can be used for manufacturing a workpiece with a protective film, which includes a workpiece obtained by processing a workpiece and a protective film provided at any location of the workpiece. In particular, when manufacturing a workpiece with a protective film by heating a workpiece with a protective film forming film, it is preferable to use the protective film forming film and the composite sheet for forming the protective film.

[0232] The method for manufacturing a workpiece with a protective film according to the present embodiment includes a pasting step of producing a workpiece with a protective film forming film including the workpiece and the protective film forming film by pasting the protective film forming film that does not constitute the composite sheet for forming the protective film or the protective film forming film in the composite sheet for forming the protective film to a target location of the workpiece; a processing step of producing the workpiece by processing the workpiece after the pasting step; a cutting step of cutting the protective film forming film after the pasting step; and a thermosetting step of producing the workpiece with a protective film by thermosetting the cut protective film forming film at a temperature of 160 to 170°C to form a protective film after the processing step and the cutting step. When the workpiece is a wafer, examples of the workpiece with a protective film include a chip with a protective film provided on the back surface of the chip. The method for manufacturing the chip with a protective film includes a pasting step of producing a wafer with a protective film forming film including the wafer and the protective film forming film provided on the back surface of the wafer by pasting the protective film forming film that does not constitute the composite sheet for forming the protective film or the protective film forming film in the composite sheet for forming the protective film to the back surface of the wafer; a processing step (which may also be referred to as a "dicing step") of producing chips by dicing the wafer after the pasting step; a cutting step of cutting the protective film forming film after the pasting step; and a thermosetting step of producing the chip with a protective film by thermosetting the cut protective film forming film at a temperature of 160 to 170°C to form a protective film after the processing step and the cutting step.

[0233] Hereinafter, as a method for manufacturing a workpiece with a protective film, a method for manufacturing a chip with a protective film will be taken as an example and described with reference to the drawings. FIG. 6 is a cross-sectional view for schematically explaining an example of a manufacturing method (hereinafter sometimes referred to as "manufacturing method (1-1)") when using a composite sheet for forming a protective film in the manufacturing method of the chip with a protective film according to the present embodiment. Here, the case of using the composite sheet 101 for forming a protective film shown in FIG. 2 will be described.

[0234] <<Manufacturing method of chip with protective film (manufacturing method (1-1))>> In the pasting step of the manufacturing method (1-1), as shown in FIG. 6(a), the protective film forming film 13 in the composite sheet 101 for forming a protective film from which the release film 15 has been removed is pasted on the back surface 9b of the wafer 9, thereby producing a wafer 901 with a protective film forming film. The first surface 13a of the protective film forming film 13 is bonded to the back surface 9b of the wafer 9.

[0235] The pasting of the protective film forming film 13 onto the wafer 9 can be performed by a known method such as a method using a roll.

[0236] 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 speed of pasting the protective film forming film 13 (pasting speed) 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.

[0237] After the pasting step of the manufacturing method (1-1), in the processing step, the wafer 9 is divided to produce chips 90. Also, after the pasting step, in the cutting step, the protective film forming film 13 is cut. By performing the processing step and the cutting step, as shown in Fig. 6(b), a chip 90 with a protective film forming film 130 provided on its back surface 90b is produced, and on the support sheet 10, a chip group 902 with a protective film forming film, in which a plurality of these chips 913 with a protective film forming film are held in an aligned state, is produced. In Fig. 6(b), reference numeral 130a indicates the first surface of the protective film forming film 130 after cutting, corresponding to the first surface 13a of the protective film forming film 13. Further, reference numeral 130b indicates the second surface of the protective film forming film 130 after cutting, corresponding to the second surface 13b of the protective film forming film 13.

[0238] In the manufacturing method (1-1), after the pasting step, it is preferable to perform the processing step and the cutting step simultaneously, or to perform the cutting step after performing the processing step. In the manufacturing method (1-1), when the processing (dicing) of the wafer and the cutting of the protective film forming film are continuously performed by the same operation without interruption regardless of the order, it is regarded as performing the processing step and the cutting step simultaneously.

[0239] Both the processing step and the cutting step can be performed by known methods according to the order in which they are performed.

[0240] For example, when performing the processing step and the cutting step simultaneously, dicing such as blade dicing using a blade, laser dicing by laser irradiation, or water dicing by spraying water containing an abrasive can be used to simultaneously perform the dicing of the wafer 9 and the cutting of the protective film forming film 13. Also, by performing a so-called expand operation in which both the wafer 9 on which a modified layer is formed by stealth dicing (registered trademark) and not divided and the protective film forming film 13 are pulled in a direction parallel to their surfaces, it is possible to simultaneously perform the division of the wafer 9 and the cutting of the protective film forming film 13. Such an expand operation is preferably performed at a low temperature such as -20 to 5°C.

[0241] Stealth dicing (registered trademark) is the following method. That is, first, a division planned location is set inside the wafer, and by irradiating laser light so as to focus on this location, a modified layer is formed inside the wafer. The modified layer of the wafer is different from other parts of the wafer in that it has been altered by the irradiation of laser light and its strength has weakened. Therefore, when a force is applied to the wafer, cracks extending in both surface directions of the wafer occur in the modified layer inside the wafer, which becomes the starting point for dividing the wafer. Next, a force is applied to the wafer to divide the wafer at the site of the modified layer and produce chips.

[0242] After the processing step and the cutting step of the manufacturing method (1-1), in the heat curing step, the cut protective film forming film 130 is heat cured at a temperature of 160 to 170°C to form a protective film 130'. As a result, as shown in FIG. 6(c), a chip 90 with a protective film 913' provided with a protective film 130' on its back surface 90b is produced, and on the support sheet 10, a group of chips with protective films 903 is produced in which a plurality of these chips with protective films 913' are held in an aligned state. In FIG. 6(c), reference numeral 130a' indicates the first surface of the protective film 130', which corresponds to the first surface 130a of the cut protective film forming film 130. Also, reference numeral 130b' indicates the second surface of the protective film 130', which corresponds to the second surface 130b of the cut protective film forming film 130.

[0243] When using a conventional protective film-forming film, if it is thermally cured at a temperature higher than the conventional 160 to 170 °C, before the protective film-forming film is sufficiently cured, the fluidity of the protective film-forming film becomes higher than before. Then, between the chips with the protective film-forming film existing in the vicinity, it is easy for the protective film-forming films to come into contact with each other. When they come into contact and adhere, the curing of the protective film-forming film proceeds in this adhered state, and defective products in which a plurality of chips are connected by the protective film are produced. On the other hand, in the case of the manufacturing method (1-1) using the protective film-forming film of the present embodiment, such abnormal occurrence in the protective film can be suppressed.

[0244] In the thermal curing step, the chip group 902 with the protective film-forming film can be arranged (so-called "placed horizontally") so that its surface (for example, the first surface 130a of the protective film-forming film 130 after cutting, the back surface 90b of the chip 90) is parallel to the horizontal direction, and the protective film-forming film 130 can be thermally cured. On the other hand, in the thermal curing step, the chip group 902 with the protective film-forming film can be arranged (so-called "placed vertically") so that its surface (the same as above) is orthogonal to the horizontal direction (in other words, parallel to the vertical direction), and the protective film-forming film 130 can be thermally cured. When the chip group 902 with the protective film-forming film is heated in a vertical position in this way, the occurrence of slack in the region of the support sheet 10 that holds the chip 913' with the protective film can be suppressed more than when it is heated in a horizontal position.

[0245] After the thermal curing step of the manufacturing method (1-1), as shown in FIG. 6(d), by performing a pickup step of separating and picking up the chip 913' with the protective film in the chip group 903 with the protective film from the support sheet 10, the target chip 913' with the protective film can be taken out. In the pickup step of the manufacturing method (1-1), peeling occurs between the second surface 130b' of the protective film 130' in the chip 913' with the protective film and the first surface 12a of the adhesive layer 12 in the support sheet 10.

[0246] The chip 913' with a protective film can be picked up by a known method. Here, the case is shown where the chip 913' with a protective film is separated in the direction of arrow P using separation means 7 such as a vacuum collet.

[0247] So far, as the manufacturing method (1-1), the manufacturing method of the chip with a protective film when using a composite sheet for forming a protective film has been described. However, even if a protective film forming film that does not constitute a composite sheet for forming a protective film is used instead of the composite sheet for forming a protective film, a chip with a protective film can be manufactured. FIG. 7 is a cross-sectional view for schematically explaining an example of a manufacturing method (which may be referred to as "manufacturing method (1-2)" in this specification) when using a protective film forming film that does not constitute a composite sheet for forming a protective film among the manufacturing methods of the chip with a protective film according to the present embodiment. Here, the case where the protective film forming film 13 shown in FIG. 1 is used will be described.

[0248] <<Manufacturing method of chip with protective film (manufacturing method (1-2))>> In the pasting step of the manufacturing method (1-2), as shown in FIG. 7(a), a protective film forming film 13 that does not constitute the composite sheet for forming a protective film, more specifically, the protective film forming film 13 from which the first release film 151 has been removed, is pasted on the back surface 9b of the wafer 9 to produce a wafer 901 with a protective film forming film. This step is the same as the pasting step of the manufacturing method (1-1), except that a protective film forming film 13 provided with a second release film 152 is used instead of the protective film forming film 13 that constitutes the composite sheet 101 for forming a protective film, in other words, the protective film forming film 13 provided with the support sheet 10.

[0249] The protective film forming film 13 may be cut into a circular shape having the same diameter as the wafer 9 or a diameter 1 to 10 mm smaller than the diameter of the wafer before being pasted on the back surface 9b of the wafer 9. By doing so, the workability in the pasting step and the workability of removing the second release film 152 described later are improved.

[0250] After the pasting step of the manufacturing method (1-2) and before the processing step, as shown in FIG. 7(b), the second release film 152 is removed from the wafer 901 with the protective film forming film, and thereby the newly generated exposed surface, that is, the second surface 13b of the protective film forming film 13, the dicing sheet 80 is pasted. The dicing sheet 80 includes a base material 81 and an adhesive layer 82 provided on one surface thereof. In this step, the surface (which may be referred to as the "first surface" in this specification) 82a on the side opposite to the base material 81 side of the adhesive layer 82 is pasted on 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 (1-2) has a dicing sheet pasting step of pasting a dicing sheet on the surface of the protective film forming film in the wafer with the protective film forming film, which is opposite to the wafer side, between the pasting step and the processing step.

[0251] The dicing sheet 80 may have the same configuration as the support sheet 10 in the composite sheet 101 for forming a protective film. Here, the case of using the dicing sheet 80 is shown, but in the manufacturing method (1-2), for example, a known dicing sheet other than the dicing sheet 80, such as a dicing sheet composed only of a base material, may be used.

[0252] The pasting of the dicing sheet 80 to the protective film forming film 13 can be performed by a known method. For example, it can be performed in the same manner as the pasting of the composite sheet 101 for forming a protective film to the wafer 9 in the pasting step of the manufacturing method (1-1).

[0253] In the manufacturing method (1-2), after the dicing sheet attaching step, except for using a wafer 901 with a protective film forming film having a dicing sheet 80 instead of the wafer 901 with a protective film forming film having a support sheet 10 as described above, the processing step, cutting step, thermosetting step, and pickup step can be performed in the same manner as in the case of the manufacturing method (1-1), and the target chip 913' with a protective film can be manufactured and taken out.

[0254] For example, in the manufacturing method (1-2), by performing the processing step and the cutting step, as shown in FIG. 7(c), a chip 913 with a protective film forming film is produced, and on the dicing sheet 80, a chip group 904 with a protective film forming film configured to hold a plurality of these chips 913 with a protective film forming film in an aligned state is produced. The chip group 904 with a protective film forming film is the same as the chip group 902 with a protective film forming film in the manufacturing method (1-1), except that it has a dicing sheet 80 instead of a support sheet 10.

[0255] For example, in the manufacturing method (1-2), by performing the thermosetting step, as shown in FIG. 7(d), a chip 913' with a protective film is produced, and on the dicing sheet 80, a chip group 905 with a protective film configured to hold a plurality of these chips 913' with a protective film in an aligned state is produced. The chip group 905 with a protective film is the same as the chip group 903 with a protective film in the manufacturing method (1-1), except that it has a dicing sheet 80 instead of a support sheet 10. Also in the case of the manufacturing method (1-2) using the protective film forming film of the present embodiment, the occurrence of abnormalities in the protective film as described above can be suppressed.

[0256] Also in the thermosetting step of the manufacturing method (1-2), by placing the chip group 904 with a protective film forming film vertically and thermosetting the protective film forming film 130, the occurrence of slack in the region of the support sheet 10 that holds the chip 913' with a protective film can be suppressed.

[0257] For example, after the heat curing step of the manufacturing method (1-2), as shown in FIG. 7(e), a pickup step is performed to separate and pick up the chip 913' with a protective film in the chip group 905 with a protective film from the dicing sheet 80, whereby the target chip 913' with a protective film can be taken out. In the pickup step of the manufacturing method (1-2), peeling occurs between the second surface 130b' of the protective film 130' in the chip 913' with a protective film and the first surface 82a of the adhesive layer 82 in the dicing sheet 80.

[0258] <<Modification Example of Manufacturing Method of Workpiece with Protective Film>> The manufacturing method of the workpiece with a protective film according to the present embodiment may have other steps that do not fall into any of the pasting step, the processing step, the cutting step, the heat curing step, the pickup step, and the dicing sheet pasting step, as long as the effects of the present invention are not impaired. The other steps can be arbitrarily selected according to the purpose and are not particularly limited. The timing of performing the other steps can be appropriately selected according to the content of the other steps.

[0259] As an example of the other steps in the manufacturing method of the chip with a protective film, a back grind tape pasting step of pasting a back grind tape on the back surface of the wafer before the pasting step, and a back grind tape removing step of removing the back grind tape from the back surface of the wafer after the back grind tape pasting step and before the processing step and the cutting step can be mentioned. The back grind tape may be a known one, and the pasting of the back grind tape on the back surface of the wafer and the removal of the back grind tape from the back surface of the wafer can be performed by known methods.

[0260] In this specification, the description of merely "the pasting step" does not correspond to either the "dicing sheet pasting step" or the "back grind tape pasting step", but means the step of pasting the above-described protective film forming film or the protective film forming film in the composite sheet for forming a protective film to a target location (for example, the back surface of a wafer) of the work.

[0261] As another example of the other steps in the method for manufacturing the chip with a protective film, after the pasting step and before the pickup step, there is a printing step of performing laser printing on the surface of the protective film forming film or the protective film on the side opposite to the wafer side or the side opposite to the chip side. Laser printing on the protective film forming film or the protective film can be performed by a known method.

[0262] So far, as the manufacturing method (1-1), the case of using the composite sheet 101 for forming a protective film shown in FIG. 2 has been described. However, in the manufacturing method of the work processed product with a protective film of the present embodiment, other composite sheets for forming a protective film such as the composite sheet 102 for forming a protective film shown in FIG. 3, the composite sheet 103 for forming a protective film shown in FIG. 4, the composite sheet 104 for forming a protective film shown in FIG. 5, etc. may be used. When using the other composite sheet for forming a protective film, based on the difference in configuration between the other composite sheet for forming a protective film and the composite sheet 101 for forming a protective film shown in FIG. 2, the manufacturing method of the work processed product with a protective film of the present embodiment may have the other steps performed at any timing.

[0263] ◇ Method for manufacturing a work with a protective film (Method for using a protective film forming film and a composite sheet for forming a protective film) The protective film forming film and the composite sheet for forming a protective film can be used for manufacturing a work with a protective film including a work and a protective film provided at any location of the work. The manufacturing method of the work with a protective film of the present embodiment is different from the above-described manufacturing method of the work processed product with a protective film in that it does not have a step of producing a work processed product by processing the work.

[0264] The manufacturing method of the work with a protective film according to this embodiment includes an attaching step of producing a work with a protective film forming film including the work and a protective film forming film by attaching a protective film forming film that does not constitute the composite sheet for forming a protective film, or the protective film forming film in the composite sheet for forming a protective film, to a target location of the work, and a thermosetting step of producing the work with a protective film by thermosetting the protective film forming film at a temperature of 160 to 170°C to form a protective film after the attaching step. When the work is a wafer, examples of the work with a protective film include a wafer with a protective film including the wafer and a protective film provided on the back surface of the wafer. The manufacturing method of the wafer with a protective film includes an attaching step of producing a wafer with a protective film forming film including the wafer and the protective film forming film provided on the back surface of the wafer by attaching a protective film forming film that does not constitute the composite sheet for forming a protective film, or the protective film forming film in the composite sheet for forming a protective film, to the back surface of the wafer, and a thermosetting step of producing the work with a protective film by thermosetting the protective film forming film at a temperature of 160 to 170°C to form a protective film after the attaching step.

[0265] Hereinafter, as a manufacturing method of a work with a protective film, a manufacturing method of a wafer with a protective film will be described by way of example with reference to the drawings. FIG. 8 is a cross-sectional view for schematically explaining an example of a manufacturing method (which may be referred to as "manufacturing method (2-1)" in this specification) when using a composite sheet for forming a protective film in the manufacturing method of the wafer with a protective film according to this embodiment. Here, the case of using the composite sheet 101 for forming a protective film shown in FIG. 2 will be described.

[0266] <<Manufacturing method of wafer with protective film (Manufacturing method (2-1))>> In the pasting step of the manufacturing method (2-1), as shown in Fig. 8(a), the protective film forming film 13 in the composite sheet 101 for forming a protective film from which the release film 15 has been removed is pasted onto the back surface 9b of the wafer 9, thereby producing a wafer 901 with a protective film forming film. The pasting step of the manufacturing method (2-1) is the same as the pasting step of the manufacturing method (1-1).

[0267] After the pasting step of the manufacturing method (2-1), in the thermosetting step, the protective film forming film 13 pasted onto the wafer 9 is thermoset at a temperature of 160 to 170°C to form a protective film 13', thereby producing a wafer 906 with a protective film as shown in Fig. 8(b). The thermosetting step of the manufacturing method (2-1) can be performed in the same manner as in the case of the thermosetting step of the manufacturing method (1-1).

[0268] When using a conventional protective film forming film, if it is thermoset at a temperature higher than the conventional 160 to 170°C, the fluidity of the protective film forming film becomes higher than before the protective film forming film is sufficiently cured. Then, the protective film forming film disposed at the peripheral portion along the outer periphery of the wafer in the wafer with the protective film forming film is deformed, and typically, the thickness becomes thinner at the portion closer to the outer periphery. Such a phenomenon is also likely to be affected by the hot air generated during heating. In such a case, when the wafer is then divided to produce chips and the protective film is cut to produce chips with a protective film, in the chips with a protective film produced from the portion close to the outer periphery of the wafer, the thickness of the protective film is thinner than normal or the protective film forms an inclined surface, resulting in the production of defective products. On the other hand, in the case of the manufacturing method (2-1) using the protective film forming film of the present embodiment, such abnormal occurrences in the protective film can be suppressed.

[0269] Using the wafer 906 with the protective film obtained above, the wafer 9 is divided, and by cutting the protective film 13', a chip with a protective film (not shown) can be produced, and on the support sheet 10, a group of chips with protective films can be produced, which are configured to hold a plurality of these chips with protective films in an aligned state. The group of chips with protective films obtained here is, for example, the same as the group of chips with protective films 903 obtained by the manufacturing method (1-1).

[0270] The division of the wafer 9 and the cutting of the protective film 13' are preferably performed simultaneously or the cutting of the protective film 13' is performed after the division of the wafer 9. The method of dividing the wafer 9 may be, for example, the same as the method of dividing the wafer 9 in the processing step of the manufacturing method (1-1). The cutting of the protective film 13' may be a known method, for example, the same as the method of cutting the protective film forming film 13 in the cutting step of the manufacturing method (1-1).

[0271] Using the obtained chip with a protective film, the chip with a protective film can be taken out by separating the chip with a protective film from the support sheet 10 and picking it up. The process at this time may be the same as the pickup process described in the manufacturing method (1-1).

[0272] So far, as the manufacturing method (2-1), the manufacturing method of the wafer with a protective film when using the composite sheet for forming a protective film has been described. However, even if a protective film forming film that does not constitute the composite sheet for forming a protective film is used instead of the composite sheet for forming a protective film, a wafer with a protective film can be manufactured. FIG. 9 is a cross-sectional view for schematically explaining an example of the manufacturing method when using a protective film forming film that does not constitute the composite sheet for forming a protective film in the manufacturing method of the wafer with a protective film of the present embodiment (in this specification, it may be referred to as "manufacturing method (2-2)"). Here, the case of using the protective film forming film 13 shown in FIG. 1 will be described.

[0273] <<Manufacturing Method of Wafer with Protective Film (Manufacturing Method (2-2))>> In the pasting step of the manufacturing method (2-2), as shown in Fig. 9(a), the protective film forming film 13 that does not constitute the composite sheet for forming the protective film, more specifically, the protective film forming film 13 with the first release film 151 removed, is pasted onto the back surface 9b of the wafer 9 to produce a wafer 901 with a protective film forming film. This step is the same as the pasting step of the manufacturing method (2-1), except that in place of the protective film forming film 13 that constitutes the composite sheet 101 for forming the protective film, that is, the protective film forming film 13 provided with the support sheet 10, a protective film forming film 13 provided with the second release film 152 is used.

[0274] Also in the manufacturing method (2-2), the protective film forming film 13 may be cut into a circular shape with the same diameter as the wafer 9 or a diameter 1 to 10 mm smaller than the diameter of the wafer before being pasted onto the back surface 9b of the wafer 9. By doing so, the workability in the pasting step and the workability of removing the second release film 152 described later are improved.

[0275] After the pasting step of the manufacturing method (2-2) and before the thermosetting step, the second release film 152 is removed from the wafer 901 with the protective film forming film. Next, in the thermosetting step, the protective film forming film 13 is thermoset at a temperature of 160 to 170 °C to form the protective film 13', thereby producing a wafer 906 with a protective film, as shown in Fig. 9(b). The thermosetting step of the manufacturing method (2-2) is the same as the thermosetting step of the manufacturing method (2-1), except that in place of the wafer 901 with the protective film forming film provided with the support sheet 10, a wafer 901 with the protective film forming film without the support sheet 10 (the second surface 13b of the protective film forming film 13 is the exposed surface) is used. Even in the case of the manufacturing method (2-2) using the protective film forming film of the present embodiment, the occurrence of abnormalities in the protective film as described above can be suppressed.

[0276] Generally, as described above, when the protective film forming film before being attached to the back surface 9b of the wafer 9 is cut into a circular shape with the same diameter as the wafer 9 or a diameter 1 to 10 mm smaller than the diameter of the wafer, if the protective film forming film is thermally cured at a temperature of 160 to 170 °C, deformation of the protective film forming film disposed at the peripheral portion of the wafer, which was described above, is more likely to occur than in the case where the protective film forming film is not cut in this way or in the case of the manufacturing method (2-1). On the other hand, when the protective film forming film of the present embodiment is used, such deformation of the protective film forming film is suppressed. Therefore, as described above, when the protective film forming film before being attached to the back surface 9b of the wafer 9 is cut and the manufacturing method (2-2) is adopted, the effect of suppressing the occurrence of abnormalities in the protective film is more significantly exhibited.

[0277] For example, after the thermal curing step of the manufacturing method (2-2), a dicing sheet (not shown) is attached to the second surface 13b of the protective film forming film 13 in the wafer 906 with the protective film, the wafer 9 is divided, and the protective film 13' is cut, whereby a chip with the protective film (not shown) can be produced, and on the dicing sheet, a group of chips with the protective film configured to hold a plurality of these chips with the protective film aligned can be produced. The group of chips with the protective film obtained here may be the same as, for example, the group of chips with the protective film 905 obtained by the manufacturing method (1-2).

[0278] The division of the wafer 9 and the cutting of the protective film 13' are performed after the dicing sheet is attached to the protective film forming film 13. The dicing sheet may be a known one, and for example, may be the same as the dicing sheet 80 used in the manufacturing method (1-2). The division of the wafer 9 and the cutting of the protective film 13' may be performed by a known method, and for example, may be performed in the same manner as in the case of the manufacturing method (2-1).

[0279] Using the obtained chip with the protective film, the chip with the protective film can be taken out by separating and picking up the chip with the protective film from the support sheet 10. The process at this time may be the same as the pickup process described in the manufacturing method (1-2).

[0280] <<Modification Example of Manufacturing Method of Workpiece with Protective Film>> The manufacturing method of the workpiece with the protective film of the present embodiment may have other processes that do not fall into either the pasting process or the thermosetting process, as long as the effects of the present invention are not impaired. The other processes can be arbitrarily selected according to the purpose and are not particularly limited. The timing of performing the other processes can be appropriately selected according to the content of the other processes.

[0281] As an example of the other processes in the manufacturing method of the wafer with the protective film, in the case of using a wafer provided with a back grind tape on its back surface, before the pasting process, a back grind tape removing process of removing the back grind tape from the back surface of the wafer can be mentioned. The back grind tape may be a known one, and the pasting of the back grind tape to the back surface of the wafer and the removal from the back surface of the wafer can be performed by known methods.

[0282] So far, as the manufacturing method (2-1), the case of using the composite sheet 101 for forming a protective film shown in FIG. 2 has been described. However, in the manufacturing method of the workpiece with a protective film of the present embodiment, other composite sheets for forming a protective film such as the composite sheet 102 for forming a protective film shown in FIG. 3, the composite sheet 103 for forming a protective film shown in FIG. 4, and the composite sheet 104 for forming a protective film shown in FIG. 5 may be used. When using the other composite sheets for forming a protective film, based on the difference in the configuration between the other composite sheets for forming a protective film and the composite sheet 101 for forming a protective film shown in FIG. 2, the manufacturing method of the workpiece with a protective film of the present embodiment may have the other processes performed at any timing.

[0283] ◇ Manufacturing method of substrate device (method of using chip with protective film) After obtaining the chip with protective film by the above manufacturing method, a substrate device can be manufactured in the same manner as the conventional manufacturing method of substrate devices, except that this chip with protective film is used instead of the conventional chip with protective film.

[0284] As such a manufacturing method of a substrate device, for example, there is a manufacturing method having a flip chip connection step of electrically connecting the protruding electrode on the chip with protective film obtained by using the protective film forming film to the connection pad on the circuit board by bringing the protruding electrode into contact with the connection pad on the circuit board.

Example

[0285] Hereinafter, the present invention will be described in more detail with specific examples. However, the present invention is not limited to the examples shown below at all.

[0286] <Raw materials for resin production> The official names of the raw materials for resin production, which are abbreviated in the present examples and comparative examples, are shown below. MA: Methyl acrylate HEA: 2-Hydroxyethyl acrylate 2EHA: 2-Ethylhexyl acrylate GMA: Glycidyl methacrylate AAc: Acrylic acid MMA: Methyl methacrylate BA: n-Butyl acrylate EA: Ethyl acrylate AN: Acrylonitrile

[0287] <Raw materials for manufacturing the protective film-forming composition> The raw materials used for manufacturing the protective film-forming composition are shown below. [Polymer component (A)] (A)-1: Acrylic copolymer ("Taisen Resin SG-P3" manufactured by Nagase ChemteX Corporation) (A)-2: An acrylic polymer obtained by copolymerizing 2-EHA (62 parts by mass), MA (12 parts by mass), GMA (7 parts by mass), AAc (1 part by mass) and HEA (18 parts by mass) (weight average molecular weight 500,000, glass transition temperature -47 °C) (A)-3: An acrylic polymer obtained by copolymerizing 2-EHA (65 parts by mass), MA (11 parts by mass), GMA (7 parts by mass) and HEA (17 parts by mass) (weight average molecular weight 500,000, glass transition temperature -49 °C) (A)-4: An acrylic polymer obtained by copolymerizing MA (97 parts by mass) and HEA (3 parts by mass) (weight average molecular weight 500,000, glass transition temperature 9 °C) (A)-5: An acrylic resin obtained by copolymerizing BA (45 parts by mass), MA (38 parts by mass), GMA (3 parts by mass) and HEA (14 parts by mass) (weight average molecular weight 400,000, glass transition temperature -25 °C) [Epoxy resin (B1)] (B1)-1: Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, "jER828", epoxy equivalent 184 - 194 g / eq) (B1)-2: Dicyclopentadiene type epoxy resin (manufactured by DIC Corporation, "Epiclon HP-7200", epoxy equivalent 254 - 264 g / eq) [Thermosetting agent (B2)] (B2)-1: Dicyandiamide (thermal activation latent epoxy resin curing agent, manufactured by Mitsubishi Chemical Corporation, "DICY7") [Curing accelerator (C)] (C)-1: 2-Phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals Corporation, "Curezol 2PHZ") [Filler (D)] (D)-1: Silica filler (manufactured by Admatechs Co., Ltd., "Y100SV-CM1", spherical silica filler surface-modified with vinyl groups, average particle diameter 0.1 μm) (D)-2: Silica filler (manufactured by Admatechs Co., Ltd., "SC105G-MMQ", spherical silica filler surface-modified with vinyl groups, average particle diameter 0.3 μm) (D)-3: Silica filler (manufactured by Admatechs Co., Ltd., "3SE-CM6", spherical silica filler surface-modified with epoxy groups, average particle diameter 0.3 μm) (D)-4: Silica filler ("SC2050MA" manufactured by Admatechs Co., Ltd., spherical silica filler surface-modified with epoxy groups, average particle diameter 0.5 μm) [Coupling agent (E)] (E)-1: Oligomeric silane coupling agent having epoxy groups, methyl groups and methoxy groups ("X-41-1056" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent 280 g / eq) [Colorant (I)] (I)-1: Organic black pigment ("6377 Black" manufactured by Dainichi Seika Kogyo Co., Ltd.)

[0288] [Example 1] [[Manufacture of protective film-forming film]] [[Manufacture of protective film-forming composition (III)-1]] 25 parts by mass of polymer component (A)-1, 10 parts by mass of epoxy resin (B1)-1, 5 parts by mass of epoxy resin (B1)-2, 0.1 part by mass of thermosetting agent (B2)-1, 0.1 part by mass of curing accelerator (C)-1, 57.5 parts by mass of filler (D)-1, 0.3 part by mass of coupling agent (E)-1 and 2 parts by mass of colorant (I)-1 were dissolved or dispersed in methyl ethyl ketone and stirred at 23 °C to obtain a thermosetting protective film-forming composition (III)-1 in which the total concentration of all components other than the solvent was 60% by mass. The blending amounts of the components other than methyl ethyl ketone shown here are all the blending amounts of the target product without the solvent.

[0289] [[Manufacture of protective film-forming film]] Using a release film (second release film, "SP-PET502150" manufactured by Lintec Co., Ltd., thickness 50 μm) with one side of a polyethylene terephthalate film subjected to a release treatment by silicone treatment, the protective film-forming composition (III)-1 obtained above was coated on the release-treated surface and dried at 100 °C for 2 minutes to produce a thermosetting protective film-forming film with a thickness of 40 μm.

[0290] Furthermore, on the exposed surface of the obtained protective film-forming film on the side without the second release film, under the conditions of a sticking speed of 2 m / min, a sticking temperature of 60°C, and a sticking pressure of 0.5 MPa, the release-treated surface of a release film (the first release film, "SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) was bonded. As a result, a protective film-forming film with a release film, which is composed of a protective film-forming film, a first release film provided on one surface of the protective film-forming film, and a second release film provided on the other surface of the protective film-forming film, was manufactured.

[0291] <<Evaluation of Protective Film-Forming Film>> <Measurement of Storage Elastic Modulus E' of Test Specimen> Using the five protective film-forming films with release films obtained above, while removing these first release films or second release films, the exposed surfaces of the protective film-forming films were sequentially bonded together to produce a laminate composed of a second release film, five protective film-forming films (total thickness 200 μm), and a second release film in this order. Then, a section with a width of 4 mm and a length of 30 mm was cut out from this laminate. Next, the two outermost second release films were removed from this section, and the resulting product was used as a test specimen. Next, using a dynamic viscoelasticity automatic measuring device ("Rheovibron DDV-01FP" manufactured by A&D Company), by the tensile method (tensile mode), under the measurement conditions of a chuck distance of 20 mm, a frequency of 11 Hz, a heating rate of 3°C / min, and isothermal heating, the storage elastic modulus E' of the test specimen was measured in the temperature range from -10°C to 170°C. Among them, E'(160) and E'(170) are shown in Table 1.

[0292] <<Manufacture of Composite Sheet for Protective Film Formation>> <Manufacture of Adhesive Composition (I-4)> 100 parts by mass of an acrylic resin, which is an adhesive resin (I-1a), and 20 parts by mass of a crosslinking agent (xylene diisocyanate adduct of trimethylolpropane, "Takenate D110N" manufactured by Mitsui Takeda Chemicals, Inc.) were mixed, further diluted with methyl ethyl ketone, and stirred at 23°C to produce an adhesive composition (I-4) in which the total concentration of the two components other than the above-mentioned methyl ethyl ketone is 25% by mass. The blending amounts of the two components other than methyl ethyl ketone shown here are all the blending amounts of the target product without solvent. The acrylic resin used here is a (meth)acrylic acid ester copolymer (weight average molecular weight 600,000) obtained by copolymerizing 2EHA (60 parts by mass), MMA (30 parts by mass), and HEA (10 parts by mass).

[0293] <Manufacture of Support Sheet> Using a release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) in which one side of a polyethylene terephthalate film was subjected to a release treatment by silicone treatment, the adhesive composition (I-4) obtained above was applied to the release-treated surface using a knife coater, and heated and dried at 100°C for 2 minutes to form a non-energy-ray curable adhesive layer (thickness 5 μm).

[0294] Next, as a base material, an uncolored polypropylene film (thickness 80 μm, melting point 156°C, surface roughness (Ra) of the matte surface on one side 0.20 μm, surface roughness (Ra) of the micro-matte surface on the other side 0.15 μm) was used, and the exposed surface of the adhesive layer obtained above (the surface opposite to the release film side) was attached to the matte surface to manufacture a support sheet with a release film in which the base material, the adhesive layer, and the release film were laminated in this order in the thickness direction of these layers.

[0295] <Formation of Adhesive Layer for Fixture> 100 parts by mass of an acrylic resin, which is an adhesive resin (I-1a), and 5 parts by mass of a crosslinking agent (a tolylene diisocyanate-based crosslinking agent, "Coronate L" manufactured by Tosoh Corporation) were mixed, further diluted with toluene, and stirred at 23°C to produce an adhesive composition for a jig in which the total concentration of the two components other than the above-mentioned toluene is 15% by mass. The blending amounts of the two components other than toluene shown here are all the blending amounts of the target product without a solvent. The acrylic resin used here is a (meth)acrylic acid ester copolymer (weight average molecular weight 500,000) obtained by copolymerizing BA (69.5 parts by mass), MA (30 parts by mass), and HEA (0.5 parts by mass).

[0296] A release film (first release film, "SP-PET382150" manufactured by Lintec Corporation, thickness 38 μm) in which one side of a polyethylene terephthalate film was subjected to a release treatment by silicone treatment was used. The adhesive composition for a jig obtained above was applied to the release-treated surface using a knife coater and heated and dried at 120°C for 2 minutes to form a non-energy-ray-curable adhesive layer for a jig (thickness 20 μm). Furthermore, the release-treated surface of a release film (second release film, "SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) was bonded to the exposed surface of the obtained adhesive layer for a jig on the side not provided with the first release film, thereby obtaining an adhesive layer for a jig with a release film configured to include the adhesive layer for a jig, the first release film provided on one surface of the adhesive layer for a jig, and the second release film provided on the other surface of the adhesive layer for a jig.

[0297] <Manufacture of Composite Sheet for Forming Protective Film> The first release film was removed from the protective film-forming film with a release film (thickness 40 μm) obtained above, and one surface of the protective film-forming film was exposed. The release film was removed from the support sheet with a release film obtained above, and one surface of the adhesive layer (the surface opposite to the substrate side) was exposed. By bonding the exposed one surface of the protective film forming film and the exposed one surface of the adhesive layer, a laminated sheet was manufactured in which the base material, the adhesive layer, the protective film forming film, and the second release film were laminated in this order in their thickness directions.

[0298] The first release film was removed from the adhesive layer for jig with the release film obtained above, and a circular region with a diameter of 220 mm was removed from the adhesive layer for jig.

[0299] The second release film was removed from the laminated sheet obtained above, and the exposed surface of the protective film forming film thus generated was bonded to the exposed surface of the adhesive layer for jig on the above second release film (the surface opposite to the second release film side), and these were pressure-bonded. Next, in the obtained pressure-bonded product, for the part other than the second release film, by removing the region near the outer peripheral part so that the adhesive layer for jig becomes ring-shaped, on the second release film, a laminated product of the protective film forming film, the adhesive layer, and the base material was provided in a circular shape with a diameter of 270 mm, and a composite sheet for forming a protective film with a release film having the configuration shown in FIG. 2 was manufactured. That is, a base material (thickness 80 μm), an adhesive layer (thickness 5 μm), and a protective film forming film (thickness 40 μm) were laminated in this order in their thickness directions, a ring-shaped adhesive layer for jig was provided along the peripheral edge of the surface of the protective film forming film opposite to the adhesive layer side, and a second release film was provided on the surface of the adhesive layer for jig opposite to the protective film forming film side and the exposed surface of the protective film forming film, and a composite sheet for forming a protective film with a release film was manufactured.

[0300] <<Evaluation of Protective Film Forming Film>> <Evaluation of the adhesion suppression effect (1) of the protective film between adjacent silicon chips with protective film (curing temperature 160 °C)> [Manufacture of Silicon Chip Group with Protective Film Forming Film] The second release film was removed from the composite sheet for forming a protective film obtained above, and the protective film forming film exposed inside the jig adhesive layer in the radial direction of the composite sheet for forming a protective film was attached to the dry polished surface of a silicon wafer (diameter 8 inches, thickness 350 μm, silicon mirror wafer). Thus, a laminate in which the silicon wafer, the protective film forming film, and the support sheet were laminated in this order, that is, a silicon wafer with a composite sheet for forming a protective film was produced. The sticking temperature at this time was 70°C, the sticking speed was 0.3 m / min, and the sticking pressure was 0.3 MPa. Further, this silicon wafer with a composite sheet for forming a protective film was attached to a ring frame with the jig adhesive layer and left standing for 30 minutes.

[0301] Next, using a dicing apparatus ("DFD6361" manufactured by DISCO) and a dicing blade (ZH05-SD2000-N1-90), under the conditions of a moving speed of the dicing blade of 50 mm / sec and a rotational speed of the dicing blade of 40,000 rpm, the silicon wafer and the protective film forming film in the silicon wafer with a composite sheet for forming a protective film after standing were diced. As a result, a plurality of silicon chips with protective film forming films, each having a size of 2 mm × 5 mm and a protective film forming film of the same size (2 mm × 5 mm) provided on its dry polished surface, were aligned and fixed on the adhesive layer to produce a group of silicon chips with protective film forming films. In this group of silicon chips with protective film forming films, the width of the dicing line (kerf width) was 25 to 30 μm.

[0302] [Manufacture of Group of Silicon Chips with Protective Films] The group of silicon chips with protective film forming films obtained above was installed inside an oven. At this time, the surface of the group of silicon chips with protective film forming films was made orthogonal to the horizontal direction, and the group of silicon chips with protective film forming films was placed vertically. Next, while maintaining this state, the group of silicon chips with the protective film-forming film was heated at 160°C for 1 hour, and the protective film-forming film was thermally cured to form a protective film, thereby producing a group of silicon chips with a protective film.

[0303] [Evaluation of the adhesion suppression effect (1) of the protective film (curing temperature 160°C)] Regarding the region corresponding to 8 columns of silicon chips with a protective film in two directions perpendicular to each other near the center in the group of silicon chips with a protective film obtained above, that is, the region corresponding to 64 silicon chips, using a digital microscope, focusing on the presence or absence of dicing lines, the presence or absence of adhesion of the protective film between adjacent silicon chips with a protective film was confirmed. Then, the adhesion suppression effect of the protective film was evaluated according to the following criteria. The results are shown in the column of "(1) 160°C" of "Adhesion suppression effect of the protective film" in Table 1. (Evaluation criteria) A: No adhesion of the protective film is observed at all. B: There are 2 to 4 silicon chips with a protective film where adhesion of the protective film is observed. C: There are 5 or more silicon chips with a protective film where adhesion of the protective film is observed.

[0304] <Evaluation of the deformation suppression effect (1) of the protective film arranged at the peripheral part of the silicon wafer in the silicon wafer with a protective film (curing temperature 160°C)> The adhesion suppression effect of the protective film between adjacent silicon chips with a protective film was evaluated in the same manner as in the case of the evaluation of the adhesion suppression effect (1) of the protective film above, except that the heating temperature of the group of silicon chips with the protective film-forming film was changed to 170°C instead of 160°C (evaluation of the adhesion suppression effect (2) of the protective film). The results are shown in the column of "(2) 170°C" of "Adhesion suppression effect of the protective film" in Table 1.

[0305] [Manufacture of silicon wafer with a protective film] [Manufacture of silicon wafer with a protective film] The protective film-forming film with a release film obtained above (thickness: 40 μm) was cut into a circular shape with a diameter 4 mm smaller than the diameter of the silicon wafer described later. Next, the first release film was removed from this circular protective film-forming film with a release film, and one surface of the protective film-forming film was exposed. Next, this one surface (exposed surface) of the protective film-forming film was attached to the dry-polished surface of a silicon wafer (diameter: 8 inches, thickness: 350 μm, silicon mirror wafer). At this time, the attachment temperature was 70°C, the attachment speed was 0.3 m / min, and the attachment pressure was 0.3 MPa. Also, at this time, the position of the center of the protective film-forming film and the position of the center of the silicon wafer were made to coincide in their surface directions. Next, by removing the second release film from the protective film-forming film, a silicon wafer with a protective film-forming film provided on its dry-polished surface was produced.

[0306] Next, this silicon wafer with a protective film-forming film was placed inside an oven. At this time, the surface of the silicon wafer with a protective film-forming film was made perpendicular to the horizontal direction, and the silicon wafer with a protective film-forming film was placed vertically. Next, in this state, the silicon wafer with a protective film-forming film was heated at 160°C for 1 hour, and the protective film-forming film was thermally cured to form a protective film, thereby producing a silicon wafer with a protective film provided on its dry-polished surface.

[0307] [Evaluation of the effect of suppressing deformation of the protective film (1) (curing temperature: 160°C)] Regarding the protective film in the silicon wafer with a protective film obtained above, the thicknesses at 12 locations equally spaced from each other and 0.5 mm closer to the center from its outer periphery were measured, and their average value (hereinafter referred to as "the average value of the thickness of the protective film closer to the outer periphery") was calculated. Furthermore, for this protective film, the thicknesses at 12 locations equally spaced from each other and near the outer periphery 20 mm from the center were measured, and the average value thereof (hereinafter referred to as the "average value of the thickness near the center of the protective film") was calculated. Then, the following formula: [Rate of change in thickness of protective film (%)] = ([Average value of thickness near the center of protective film] - [Average value of thickness near the outer periphery of protective film]) / [Average value of thickness near the center of protective film] × 100 was used to calculate the rate of change in the thickness of the protective film, and based on the value, the effect of suppressing deformation of the protective film was evaluated according to the following criteria. The results are shown in the column of "(1) 160°C" of "Effect of suppressing deformation of protective film" in Table 1. (Evaluation criteria) A: The rate of change in the thickness of the protective film is less than 1.5%. B: The rate of change in the thickness of the protective film is 1.5% or more and less than 3%. C: The rate of change in the thickness of the protective film is 3% or more.

[0308] (Evaluation of the effect of suppressing deformation (2) of the protective film disposed at the peripheral portion of the silicon wafer in the silicon wafer with a protective film (curing temperature 170°C)) The effect of suppressing deformation of the protective film disposed at the peripheral portion of the silicon wafer in the silicon wafer with a protective film was evaluated in the same manner as in the case of evaluating the effect of suppressing deformation (1) of the above protective film, except that the heating temperature of the silicon wafer with the protective film forming film was changed from 160°C to 170°C (evaluation of the effect of suppressing deformation (2) of the protective film). The results are shown in the column of "(2) 170°C" of "Effect of suppressing deformation of protective film" in Table 1.

[0309] (Measurement of light (550 nm) transmittance of the thermoset product of the protective film forming film) The protective film forming film with a release film (thickness 40 μm) obtained above was heat-cured by heating in a temperature range of 160 to 170°C for 1 hour. Next, in the obtained thermoset, the first release film and the second release film were removed. Then, light with a wavelength of 200 to 3000 nm was incident on the thermoset from the outside on one surface side thereof, and the light (550 nm) transmittance was measured. At this time, an integrating sphere in the measuring device was not used. The results are shown in Table 1.

[0310] <<Manufacture of protective film-forming film, manufacture of composite sheet for forming protective film, and evaluation of protective film-forming film>> [Examples 2 to 7, Comparative Examples 1 to 3] The protective film-forming film and the composite sheet for forming a protective film were manufactured and the protective film-forming film was evaluated in the same manner as in Example 1, except that the types of the compounding components were changed so that the content components and contents of the protective film-forming film were as shown in Table 1 or Table 2. The results are shown in Table 1 or Table 2.

[0311]

Table 1

[0312]

Table 2

[0313] As is clear from the above results, in Examples 1 to 7, even when the protective film-forming film was thermally cured at 160 °C or 170 °C to manufacture a silicon chip with a protective film, adhesion of the protective films between adjacent silicon chips with protective films could be suppressed. Further, in Examples 1 to 7, even when the silicon wafer with a protective film-forming film was thermally cured at 160 °C or 170 °C to manufacture a silicon wafer with a protective film, deformation of the protective film disposed at the peripheral portion of the silicon wafer therein could be suppressed. These silicon wafers with protective films were suitable for manufacturing silicon chips with protective films.

[0314] Table 1 shows only E’(160) and E’(170) as the storage elastic modulus E’ of the test pieces. However, the storage elastic modulus E’ of the test pieces in Examples 1 to 7 satisfied the condition of 1 MPa or more (5.8 MPa or more) in all temperature ranges from 160°C to 170°C. Also, the test pieces in Examples 1 to 7 showed an increase in the storage elastic modulus E’ with an increase in temperature in the temperature range from 160°C to 170°C. In the protective film-forming films of Examples 1 to 7, the polymer component (A) had a structural unit derived from an alkyl (meth)acrylate, and further had either a structural unit derived from acrylonitrile or a structural unit derived from acrylic acid. Therefore, it was presumed that the intermolecular force between the molecules of the polymer component (A) increased, and the cohesiveness of the polymer component (A) was high, so E’(160) and E’(170) were high.

[0315] Thus, the protective film-forming films of Examples 1 to 7 did not have fluidity or had low fluidity suppressed even when thermally cured at a higher temperature than before. In particular, the protective film-forming films of Examples 1, 3, 6, and 7 had both a high effect of suppressing the adhesion of the protective film and a high effect of suppressing the deformation of the protective film, and it was presumed that the effect of suppressing the flow when thermally cured at a higher temperature than before was particularly high.

[0316] The results of Examples 1, 3 to 7, particularly Examples 5 to 7, showed a tendency that the smaller the average particle diameter of the filler (D) contained in the protective film-forming film, the larger E’(160) and E’(170) became.

[0317] In Examples 1 to 7, due to the surface modification of the filler (D), the dispersibility of the filler (D) in the protective film-forming composition was good. In particular, the results of Examples 2 and 3 showed a tendency that when the filler (D) was surface-modified with an epoxy group, E’(160) and E’(170) of the protective film-forming film became high.

[0318] Thus, since the average particle diameter of the filler (D) is small and the filler (D) is surface-modified (particularly surface-modified with an epoxy group), while the dispersibility of the filler (D) in the protective film-forming composition is maintained, the force by which the particles of the filler (D) attract each other moderately increases, and since the cohesiveness of the filler (D) is high, it is presumed that E’(160) and E’(170) were high.

[0319] In Examples 1 to 7, the light (550 nm) transmittance of the thermoset product of the protective film-forming film was 13% or less, and it was clearly black, having a preferable appearance as a protective film.

[0320] On the other hand, in Comparative Examples 1 to 3, when the protective film-forming film was thermoset at 160 °C or 170 °C to produce a silicon chip with a protective film, the effect of suppressing the adhesion of the protective films between adjacent silicon chips with protective films was low. Further, in Comparative Examples 1 to 3, when a silicon wafer with a protective film-forming film was thermoset at 160 °C or 170 °C to produce a silicon wafer with a protective film, the effect of suppressing the deformation of the protective film disposed at the peripheral portion of the silicon wafer therein was low. These silicon wafers with protective films were not suitable for manufacturing silicon chips with protective films.

[0321] Table 1 shows only E’(160) and E’(170) as the storage elastic modulus E’ of the test pieces, but the storage elastic modulus E’ of the test pieces in Comparative Examples 1 to 3 satisfied the condition of less than 1 MPa (0.65 MPa or less) in all temperature ranges from 160 °C to 170 °C. Further, the test pieces in Comparative Examples 1 to 3 showed a decrease in the storage elastic modulus E’ with an increase in temperature in the temperature range from 160 °C to 170 °C.

Industrial Applicability

[0322] The present invention can be used in the manufacture of various substrate devices including semiconductor devices.

Explanation of Signs

[0323] 10, 20 ··· support sheets, 10a, 20a ··· one side (first side) of the support sheets, 11 ··· base material, 12 ··· adhesive layer, 13, 23 ··· protective film forming films, 130 ··· protective film forming film after cutting, 13’, 130’ ··· protective films, 101, 102, 103, 104 ··· composite sheets for forming protective films, 9 ··· wafer, 9b ··· back surface of the wafer, 90 ··· chip, 90b ··· back surface of the chip, 901 ··· wafer with a protective film forming film, 906 ··· wafer with a protective film, 913’ ··· chip with a protective film

Claims

1. A thermosetting protective film-forming film, the protective film-forming film contains an acrylic resin and is heat-cured at a heating temperature of 160 to 170°C; A protective film-forming film which is a laminate of a plurality of the protective film-forming films, and when a test piece having a width of 4 mm is held at two points spaced 20 mm apart and the test piece is heated from -10°C to 170°C in a tensile mode under conditions of a frequency of 11 Hz, a temperature rise rate of 3°C / min and a uniform temperature rise, and the storage modulus E' of the test piece is measured, the storage modulus E' of the test piece is 1 MPa or more in the entire temperature range from 160°C to 170°C.

2. A thermosetting protective film-forming film, The protective film-forming film contains an acrylic resin (α) having a structural unit derived from a (meth)acrylic acid alkyl ester and further having either or both of a structural unit derived from acrylonitrile and a structural unit derived from acrylic acid, The protective film-forming film contains an oligomer-type silane coupling agent, A protective film-forming film which is a laminate of a plurality of the protective film-forming films, and when a test piece having a width of 4 mm is held at two points spaced 20 mm apart and the test piece is heated from -10°C to 170°C in a tensile mode under conditions of a frequency of 11 Hz, a temperature rise rate of 3°C / min and a uniform temperature rise, and the storage modulus E' of the test piece is measured, the storage modulus E' of the test piece is 1 MPa or more in the entire temperature range from 160°C to 170°C.

3. The protective film-forming film according to claim 1 or 2, wherein the transmittance of a heat-cured product obtained by heating the protective film-forming film at a temperature range of 160 to 170 ° C. for 1 hour is 90% or less at a wavelength of 550 nm.

4. The protective film-forming film according to any one of claims 1 to 3, wherein the thickness of the protective film-forming film is less than 50 µm.

5. 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 4.

6. A method for manufacturing a workpiece with a protective film using a protective film-forming film or a composite sheet for forming a protective film, the protective film-forming film contains an acrylic resin and is thermosetting; The composite sheet for forming a protective film includes a support sheet and the protective film-forming film provided on one surface of the support sheet, A laminate of a plurality of the protective film-forming films, wherein a test piece having a width of 4 mm is held at two positions spaced 20 mm apart, and the storage modulus E' of the test piece is measured while heating the test piece from -10°C to 170°C under conditions of a frequency of 11 Hz, a temperature rise rate of 3°C / min, and a uniform temperature rise in a tensile mode, the storage modulus E' of the test piece is 1 MPa or more in the entire temperature range from 160°C to 170°C, The workpiece with a protective film includes a workpiece obtained by processing a workpiece and a protective film provided at any location on the workpiece, The manufacturing method includes a pasting step of producing a workpiece with a protective film-forming film, which includes the workpiece and the protective film-forming film, by pasting the protective film-forming film that does not constitute the protective film-forming composite sheet or the protective film-forming film in the protective film-forming composite sheet to a desired location on the workpiece; a processing step of processing the workpiece after the attaching step to produce the workpiece; a cutting step of cutting the protective film-forming film after the attaching step; The method for manufacturing a workpiece with a protective film includes a thermal curing step of thermally curing the protective film-forming film after cutting at a temperature of 160 to 170°C to form the protective film, after the processing step and cutting step, thereby producing the workpiece with the protective film.

7. A method for manufacturing a workpiece with a protective film using a protective film-forming film or a protective film-forming composite sheet, the protective film-forming film contains an acrylic resin and is thermosetting; The composite sheet for forming a protective film includes a support sheet and the protective film-forming film provided on one surface of the support sheet, A laminate of a plurality of the protective film-forming films, wherein a test piece having a width of 4 mm is held at two positions spaced 20 mm apart, and the storage modulus E' of the test piece is measured while heating the test piece from -10°C to 170°C under conditions of a frequency of 11 Hz, a temperature rise rate of 3°C / min, and a uniform temperature rise in a tensile mode, the storage modulus E' of the test piece is 1 MPa or more in the entire temperature range from 160°C to 170°C, The work with the protective film includes a work and a protective film provided at any location of the work. The manufacturing method includes an attaching step of producing a work with a protective film-forming film by attaching the protective film-forming film that does not constitute the composite sheet for forming the protective film or the protective film-forming film in the composite sheet for forming the protective film to a target location of the work, and a thermosetting step of producing the work with the protective film by thermosetting the protective film-forming film at a temperature of 160 to 170°C to form the protective film after the attaching step. A manufacturing method of a work with a protective film.

Images