Method for peeling semiconductor chip with protective film

Abstract

The present invention relates to a method for stripping a semiconductor chip with a protective film, a method for manufacturing a semiconductor chip with a protective film comprising a step of implementing the method for stripping a semiconductor chip with a protective film, and a method for manufacturing a semiconductor device including a semiconductor chip with a protective film comprising a step of implementing the method for stripping a semiconductor chip with a protective film. The method for stripping a semiconductor chip with a protective film comprises: a step (S1) of bonding a plurality of semiconductor chips with protective films to an adhesive layer (X1) with the protective film side as a bonding surface; and a step (S2) of sublimating at least a portion of the protective film of a portion of the plurality of semiconductor chips with protective films to generate gas, thereby reducing the adhesion between the portion of semiconductor chips with protective films and the adhesive layer (X1).

Description

Technical Field

[0001] The present invention relates to a method for peeling a semiconductor chip with a protective film. Background Art

[0002] In recent years, a so-called face-down mounting method has been used to manufacture semiconductor devices. In the face-down method, a semiconductor chip having electrodes such as bumps on a circuit surface is used, and the electrodes are bonded to a substrate. Therefore, the side of the semiconductor chip opposite to the circuit surface (hereinafter also referred to as the "back side of the semiconductor chip") is sometimes exposed. The back side of the exposed semiconductor chip can be protected by a protective film containing an organic material as a main component, and is sometimes assembled into a semiconductor device in the form of a semiconductor chip with a protective film.

[0003] Semiconductor chips with protective films can be obtained by singulating a semiconductor wafer with a protective film. Generally, dicing of a semiconductor wafer with a protective film is performed with the protective film side of the semiconductor wafer attached to an adhesive layer. Therefore, the semiconductor chips with protective films obtained after dicing are attached to the adhesive layer. During semiconductor device manufacturing, the semiconductor chips with protective films are peeled from the adhesive layer and used in subsequent steps.

[0004] However, as a method for peeling a semiconductor chip from an adhesive layer, there is known a method using, for example, a heat-peelable adhesive sheet having an adhesive layer containing heat-expandable particles provided on at least one side of a substrate. In this method, when peeling an adherend such as a semiconductor chip attached to the adhesive sheet, the heat-expandable particles in the adhesive layer are expanded by heating, thereby reducing the contact area between the adherend and the adhesive layer, thereby reducing the bonding strength between the adhesive layer and the adherend, and thus peeling the adherend from the adhesive sheet (for example, see Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-131507 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] The heat-peelable PSA sheet described in Patent Document 1 is generally used by heat-treating the entire surface of the PSA layer to reduce the adhesive strength to the adherend over the entire surface of the PSA layer. In other words, the adherend can be peeled from the PSA layer all at once.

[0010] However, sometimes it is not desirable to peel the adherend from the adhesive layer all at once, but rather to selectively peel only a portion. For example, in the case of an adherend comprising a semiconductor chip with a protective film, it is sometimes desirable to only remove a portion of the plurality of semiconductor chips with a protective film adhered to the adhesive layer for subsequent processing. In such a case, if the adhesion to the semiconductor chips with a protective film is reduced over the entire surface of the adhesive layer, the vibration generated when only the portion of semiconductor chips with a protective film is selectively picked up and moved may cause problems such as misalignment of the remaining semiconductor chips with a protective film and peeling from the adhesive layer.

[0011] Therefore, an object of the present invention is to provide a method for peeling semiconductor chips with protective films that can selectively reduce the adhesive force between only some of the semiconductor chips with protective films among a plurality of semiconductor chips with protective films bonded to the adhesive layer.

[0012] Solutions to the problem

[0013] The present inventors have conducted extensive research and have discovered that the aforementioned issues can be resolved by actively utilizing the protective film of a semiconductor chip with a protective film. Specifically, they discovered that the aforementioned issues can be resolved by sublimating at least a portion of the protective film of the semiconductor chip with a protective film to be peeled, thereby generating a gas that reduces the adhesive strength between the protective film and the adhesive layer. Further research has led to the completion of the present invention.

[0014] That is, the present invention relates to the following [1] to [9].

[0015] [1] A method for peeling a semiconductor chip with a protective film, comprising the following step (S1) and the following step (S2).

[0016] Step (S1): a step of laminating a plurality of semiconductor chips with protective films to the adhesive layer (X1) with the protective film side as the laminating surface;

[0017] Step (S2): a step of sublimating at least a portion of the protective film of some of the plurality of semiconductor chips with protective films to generate gas, thereby reducing the adhesive force between the semiconductor chips with protective films and the adhesive layer (X1).

[0018] [2] The peeling method described in [1] above, wherein the step (S1) includes the following steps (S1-1) to (S1-2) in sequence.

[0019] Step (S1-1): a step of laminating a semiconductor wafer with a protective film to an adhesive layer (X1) with the protective film side as the laminating surface;

[0020] Step (S1-2): a step of dicing the semiconductor wafer with a protective film to obtain the plurality of semiconductor chips with a protective film.

[0021] [3] The peeling method described in [2] above, wherein:

[0022] The semiconductor wafer with a protective film in the step (S1-1) is obtained by bonding a protective film-forming film to a semiconductor wafer and then curing the protective film-forming film.

[0023] [4] The peeling method described in [2] above, wherein:

[0024] The above-mentioned process (S1-1) is carried out as follows: a protective film-forming film is stacked on the above-mentioned adhesive layer (X1) of the adhesive sheet (X) having the above-mentioned adhesive layer (X1) to obtain a protective film-forming laminate, and after a semiconductor chip is bonded to the above-mentioned protective film-forming film side of the protective film-forming laminate, the above-mentioned protective film-forming film is cured.

[0025] [5] The peeling method according to [4] above, wherein the adhesive sheet (X) is a dicing tape.

[0026] [6] The peeling method described in any one of [1] to [5] above, wherein

[0027] The protective film of the semiconductor chip with a protective film is a protective film capable of absorbing laser light,

[0028] The step (S2) is performed by irradiating at least a portion of the protective film of the partially protective film-attached semiconductor chip with the laser beam.

[0029] [7] The peeling method described in any one of [1] to [6] above, wherein:

[0030] The following step (SP1) is performed before or after the above step (S2), and the following step (SP2) is performed after the following step (SP1) and after the above step (S2).

[0031] Step (SP1): a step of laminating the plurality of semiconductor chips with protective films to the adhesive layer (Z1) of a transfer sheet (Z) having an adhesive layer (Z1) with the side opposite to the protective film side as a laminating surface, and laminating the adhesive layer (X1) and the transfer sheet (Z) with the plurality of semiconductor chips with protective films interposed therebetween;

[0032] Step (SP2): a step of separating the transfer sheet (Z) from the adhesive layer (X1), peeling only the partially protected semiconductor chips from the adhesive layer (X1), and transferring the partially protected semiconductor chips to the transfer sheet (Z).

[0033] [8] A method for manufacturing a semiconductor chip with a protective film, comprising: performing the steps of any one of the methods described in [1] to [7].

[0034] [9] A method for manufacturing a semiconductor device including a semiconductor chip with a protective film, comprising: performing the process described in any one of [1] to [7] above.

[0035] Effects of the Invention

[0036] According to the present invention, a method for peeling semiconductor chips with protective films can be provided, which can selectively reduce the adhesive force between only some of the semiconductor chips with protective films among a plurality of semiconductor chips with protective films bonded to the adhesive layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The drawings show an example of step (S1) of the peeling method of the present invention, wherein (A) is a top view, and (B-1) and (B-2) are schematic cross-sectional views.

[0038] Figure 2 This is a schematic cross-sectional view showing an example of steps ( S1 - 1 ) to ( S1 - 2 ) of the peeling method according to one embodiment of the present invention.

[0039] Figure 3 This is a schematic cross-sectional view showing an example of step ( S2 ) of the peeling method of the present invention.

[0040] Figure 4 It will Figure 3 The portion surrounded by the dotted line is enlarged to show a schematic cross-sectional view of the process of adhesive strength reduction.

[0041] Figure 5 It is a schematic cross-sectional view showing an example of steps (SP1) to (SP2) of the peeling method according to one embodiment of the present invention.

[0042] Explanation of symbols

[0043] 1 Semiconductor wafer with protective film

[0044] 2 semiconductor chips

[0045] 11 Semiconductor chip with protective film

[0046] 12 semiconductor chips

[0047] 13 Protective film

[0048] 20 Cutting section

[0049] 30 Laser irradiation device

[0050] X Adhesive Sheet

[0051] X1 adhesive layer

[0052] Y substrate

[0053] Z transfer film

[0054] Z1 adhesive layer

[0055] Y' substrate DETAILED DESCRIPTION

[0056] In the present invention, the "active ingredient" refers to the components contained in the target composition excluding the diluent solvent.

[0057] The weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene, and specifically, is a value measured according to the method described in Examples.

[0058] In addition, "(meth)acrylic acid" means both "acrylic acid" and "methacrylic acid", and the same applies to other similar terms.

[0059] In addition, regarding preferred numerical ranges (e.g., content ranges), the lower and upper limits described in a hierarchical manner can be independently combined. For example, from the description "preferably 10 to 90, more preferably 30 to 60", the "preferable lower limit (10)" and the "more preferably upper limit (60)" can be combined to obtain "10 to 60".

[0060] [Method for peeling a semiconductor chip with a protective film]

[0061] The method for peeling a semiconductor chip with a protective film of the present invention includes the following step (S1) and the following step (S2).

[0062] Step (S1): a step of laminating a plurality of semiconductor chips with protective films to the adhesive layer (X1) with the protective film side as the laminating surface;

[0063] Step (S2): a step of sublimating at least a portion of the protective film of some of the plurality of semiconductor chips with protective films to generate gas, thereby reducing the adhesive force between the semiconductor chips with protective films and the adhesive layer (X1).

[0064] In the following description, the method for peeling a semiconductor chip with a protective film of the present invention is also simply referred to as "the peeling method of the present invention."

[0065] In addition, the method for peeling a semiconductor chip with a protective film according to one embodiment of the present invention is also simply referred to as "the peeling method according to one embodiment of the present invention."

[0066] In addition, step (S1) is also referred to as a "preparation step".

[0067] In addition, step (S2) is also referred to as "adhesive strength reducing step".

[0068] Hereinafter, step (S1) and step (S2) will be described.

[0069] [Step (S1): Preparation Step]

[0070] In step (S1), if Figure 1 As shown, a plurality of semiconductor chips 11 with protective films are bonded to the adhesive layer (X1) with the protective film 13 side as the bonding surface.

[0071] The semiconductor chip 11 with a protective film can be composed of a semiconductor chip 12 and a protective film 13. The protective film 13 is formed on the surface of the semiconductor chip 12 opposite to the circuit surface 12a, that is, the back surface 12b of the semiconductor chip 12.

[0072] The thickness of the semiconductor chip 12 is not particularly limited, but is generally 3 μm to 500 μm.

[0073] The thickness of the protective film 13 is not particularly limited, but is preferably 0.05 μm to 200 μm.

[0074] The size of the semiconductor chip 12 is not particularly limited, but is generally 5 μm to 15 mm in length and 5 μm to 15 mm in width.

[0075] Here, in Figure 1 In (B-1), a plurality of semiconductor chips 11 with protective films are attached to the adhesive layer (X1) of the adhesive sheet (X), wherein the adhesive sheet (X) is formed by laminating the adhesive layer (X1) on one side of the substrate (Y). However, this is only an example and may also be as follows. Figure 1 As shown in (B-2), a plurality of semiconductor chips 11 with protective films are bonded to an adhesive layer (X1) having no base material (Y). The adhesive layer (X1) having no base material (Y) can be used to bond and fix the plurality of semiconductor chips 11 with protective films on a surface opposite to the bonding surface to a hard substrate or the like.

[0076] In addition, the structure of the adhesive sheet (X) is not limited to Figure 1In a configuration such as (B-1), for example, an adhesive layer (X1) may be provided on both sides of the substrate (Y) (in this case, the adhesive layer (X1) on either side may also be the adhesive layer (X2) described later). In addition, a release material may be provided on the adhesive surface of the adhesive layer (X1), and the release material may be removed immediately before the plurality of semiconductor chips 11 with protective films are attached to the adhesive layer (X1) to expose the adhesive surface of the adhesive layer (X1).

[0077] <Step (S1-1), Step (S1-2)>

[0078] Here, in the preparation step of process (S1), multiple semiconductor chips 11 with protective films can be attached to the adhesive layer (X1) as described above. There is no limitation on the order of implementing process (S1), but from the perspective of efficiently implementing the present invention including the singulation process of semiconductor chips with protective films, it is preferred that in one embodiment of the peeling method of the present invention, process (S1) includes the following processes (S1-1) to (S1-2) in sequence.

[0079] Step (S1-1): Laminating the semiconductor wafer with the protective film to the adhesive layer (X1) with the protective film side as the laminating surface

[0080] Step (S1-2): dicing the semiconductor wafer with the protective film to obtain the plurality of semiconductor chips with the protective film.

[0081] (Step (S1-1))

[0082] In step (S1-1), Figure 2 As shown, the semiconductor wafer 1 with a protective film is bonded to the adhesive layer (X1) with the protective film 13 side as the bonding surface.

[0083] It should be noted that in Figure 2 In the embodiment, the semiconductor chip 1 with a protective film is bonded to the adhesive layer (X1) of the adhesive sheet (X), but this is only an example, and the semiconductor chip 1 with a protective film can also be bonded to the adhesive layer (X1) without the base material (Y).

[0084] The semiconductor wafer 1 with a protective film is composed of a semiconductor wafer 2 and a protective film 13. The protective film 13 is formed on the surface of the semiconductor wafer 2 opposite to the circuit surface 2a, that is, on the back surface 2b of the semiconductor wafer 2.

[0085] Examples of the semiconductor wafer 2 include silicon wafers, silicon carbide wafers, compound semiconductor wafers, glass wafers, and sapphire wafers. The back surface of the semiconductor wafer 2 may be appropriately ground to a thickness of approximately 3 μm to 500 μm.

[0086] In addition, the shape of the semiconductor wafer 2 is not limited to a circle, and may be a square, rectangular, or other square shape.

[0087] The thickness of the protective film 13 is preferably 0.05 μm to 200 μm.

[0088] (Step (S1-2))

[0089] In step (S1-2), if Figure 2 As shown, the semiconductor wafer 1 with a protective film is diced to obtain a plurality of semiconductor chips 11 with a protective film.

[0090] The dicing method is not particularly limited, and known methods such as blade dicing and laser dicing can be used. Dicing can be performed, for example, by providing a cutout 20 so as to penetrate the semiconductor wafer 2 and the protective film 13 .

[0091] Note that, after dicing, a chip expansion process may be performed to increase the interval between the semiconductor chips 11 with protective films (the width of the cutout portion 20 ).

[0092] (Method for Manufacturing Semiconductor Wafer with Protective Film)

[0093] The method for manufacturing the semiconductor chip with a protective film used in process (S1-1) is not particularly limited, but from the viewpoint of making the film thickness of the protective film uniform and thus achieving excellent coverage of the back side of the semiconductor chip by the protective film, the semiconductor chip with a protective film is preferably obtained by curing the protective film forming film after bonding the protective film forming film to the semiconductor chip.

[0094] The protective film-forming film can be cured by either thermal curing or curing by irradiation with energy rays, depending on the type of curable component contained in the protective film-forming film.

[0095] In this specification, “energy rays” refer to rays having energy particles among electromagnetic waves or charged particle beams, and examples thereof include ultraviolet rays and electron beams, with ultraviolet rays being preferred.

[0096] As conditions in the case of heat curing, the curing temperature is preferably 100° C. to 170° C., and the curing time is preferably 1 hour to 3 hours.

[0097] In addition, as the conditions for curing by irradiating energy rays, they can be appropriately determined according to the type of energy rays used. For example, when ultraviolet rays are used, the illuminance is preferably 170 mW / cm 2 ~250mW / cm 2 The light intensity is preferably 600mJ / cm 2~1,000mJ / cm 2 .

[0098] The protective film-forming film may be cured before or after the semiconductor wafer having the protective film-forming film bonded thereto is bonded to the adhesive layer (X1).

[0099] Here, when curing the protective film-forming film after laminating the semiconductor wafer to which the protective film-forming film is laminated to the adhesive layer (X1), it is preferred to laminate the protective film-forming film and the adhesive layer (X1) to the back surface 2b of the semiconductor wafer at once from the viewpoint of simplifying the process. Specifically, it is preferred to use a protective film-forming laminate in which the protective film-forming film is laminated on the adhesive layer (X1) of an adhesive sheet (X) having an adhesive layer (X1), and to laminate the protective film-forming film side of the protective film-forming laminate to the back surface of the semiconductor wafer before curing the protective film-forming film.

[0100] [Step (S2): Adhesion Reduction Step]

[0101] In step (S2), at least a portion of the plurality of semiconductor chips with protective films is sublimated to generate gas, thereby reducing the adhesive force between the semiconductor chips with protective films and the adhesive layer (X1).

[0102] As a method for selectively reducing the adhesion between a portion of the semiconductor chips with protective films among a plurality of semiconductor chips with protective films and the adhesive layer (X1), the inventors of the present invention came up with the idea of ​​actively utilizing the protective film possessed by the semiconductor chips with protective films, sublimating a portion of the protective film to generate gas, and thus completed the present invention.

[0103] The method of sublimating a portion of the protective film to generate gas is not particularly limited, but is preferably performed by, for example, using a protective film capable of absorbing laser light and irradiating at least a portion of the protective film of a portion of the semiconductor chip with the protective film with laser light.

[0104] Figure 3 The embodiment of the step (S2) using laser is shown. Figure 4 It will Figure 3 The figure is an enlarged view of the portion surrounded by the dotted line, schematically showing a state in which the adhesive force between some of the semiconductor chips with protective films and the adhesive layer (X1) is reduced among the plurality of semiconductor chips with protective films.

[0105] In the step (S2) using a laser, it is preferred to irradiate the laser from the side of the adhesive layer (X1) opposite to the bonding surface of the plurality of semiconductor chips with protective films, and irradiate the protective films of the semiconductor chips with protective films. When using an adhesive sheet (X) having an adhesive layer (X1), for example, it is preferred that Figure 3 、 Figure 4 As shown, laser light L generated by a laser irradiation device 30 is incident from the substrate (Y) side of the adhesive sheet (X), and the protective film of a portion of the semiconductor chip 11a with a protective film is irradiated with laser light L. As a result, a portion of the protective film is ablated, generating sublimation gas, and the contact area between the protective film and the adhesive layer (X1) around the portion irradiated with laser light L is reduced. Furthermore, by expanding the irradiation area of ​​the protective film with laser light L, the protective film is ablated over a wide area, generating sublimation gas, thereby further reducing the contact area between the protective film and the adhesive layer (X1). As a result, the adhesion between the portion of the semiconductor chip 11a with a protective film and the adhesive layer (X1) is reduced.

[0106] It should be noted that even if the sublimated gas leaks around a portion of the semiconductor chip 11a with a protective film, the leaked sublimated gas will be released toward the cutout portion 20. Therefore, it is possible to prevent the adhesive strength of the semiconductor chip with a protective film that is not intended to be peeled off from the portion of the semiconductor chip 11a with a protective film from being reduced.

[0107] The laser irradiation device 30 is not particularly limited as long as it can irradiate laser light that can generate sublimation gas from the protective film. For example, a laser irradiation device for laser marking a protective film can be used.

[0108] Examples of such laser irradiation devices include CSM2000 manufactured by EOTechnics (green solid-state laser, wavelength: 532 nm), but the device is not necessarily limited to this device, and various devices that can oscillate laser light that can be absorbed by the protective film can be used.

[0109] Laser irradiation conditions are not particularly limited as long as the protective film can absorb the laser light. However, from the perspective of more efficiently peeling off only a portion of the semiconductor chip with the protective film, the frequency is preferably 10,000 Hz to 30,000 Hz. Furthermore, the laser beam diameter is preferably 10 μm to 100 μm, more preferably 20 μm to 40 μm. The laser output is preferably 0.1 W to 1.0 W. The laser scanning speed is preferably 50 to 200 mm / second.

[0110] In addition, for laser irradiation of the protective film of the semiconductor chip with a protective film to be peeled off, the adhesion between the protective film and the adhesive layer (X1) can be reduced by performing the laser irradiation on at least a portion of the bonding surface of the protective film and the adhesive layer (X1). However, from the viewpoint of easily reducing the adhesion further, it is preferably performed on a certain area or more of the bonding surface of the protective film and the adhesive layer (X1). Specifically, the laser irradiation area of ​​the bonding surface of the protective film and the adhesive layer (X1) is preferably 50% or more, more preferably 60% or more, further preferably 70% or more, further preferably 80% or more, further preferably 90% or more, and even more preferably 100% (i.e., the entire surface of the protective film) relative to the entire surface of the bonding surface of the protective film and the adhesive layer (X1). In addition, it is preferred that the laser irradiation of the protective film is not biased towards irradiation of a partial area, but is dispersedly irradiated across multiple areas. For example, by irradiating the edge and center of the protective film with laser light, the contact area between the protective film and the adhesive layer (X1) can be effectively reduced, thereby effectively reducing the adhesive force between the protective film and the adhesive layer (X1).

[0111] It should be noted that, as described above, the laser irradiation to the protective film is preferably performed from the side of the adhesive layer (X1) opposite to the bonding surface of the semiconductor chips with the multiple protective films toward the protective film. When using an adhesive sheet (X), it is preferably performed from the substrate (Y) side toward the protective film. In addition, it is preferably adjusted so that the laser irradiation is directed to the bonding surface of the protective film with the adhesive layer (X1) or its vicinity. Here, the bonding surface of the protective film with the adhesive layer (X1) is represented by a position within 10 μm of the bonding surface.

[0112] Next, the structures of the pressure-sensitive adhesive sheet (X) and the protective film-forming film used in the peeling method according to one embodiment of the present invention will be described below.

[0113] [Adhesive sheet (X)]

[0114] The pressure-sensitive adhesive sheet (X) has a laminated structure of a substrate (Y) and a pressure-sensitive adhesive layer (X1).

[0115] It should be noted that Figure 1 (B-1) and Figures 2 to 5 The PSA sheet (X) shown is in the form of a substrate (Y) having a PSA layer (X1) on one side, but is not limited thereto and may be a double-sided PSA sheet having a PSA layer (X2) on the other side of the substrate (Y).

[0116] In the peeling method according to one embodiment of the present invention, the pressure-sensitive adhesive sheet (X) is preferably a dicing tape. Hereinafter, each layer that the pressure-sensitive adhesive sheet (X) may have will be described.

[0117] <Base Material (Y)>

[0118] The substrate (Y) of the pressure-sensitive adhesive sheet (X) functions as a support for the pressure-sensitive adhesive layer (X1), and can be composed of, for example, a laser-transmitting resin film mainly composed of a resin material.

[0119] Specific examples of resin films include polyethylene films such as low-density polyethylene (LDPE) films, linear low-density polyethylene (LLDPE) films, and high-density polyethylene (HDPE) films; polyolefin films such as polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, ethylene-norbornene copolymer films, and norbornene resin films; ethylene copolymer films such as ethylene-vinyl acetate copolymer films, ethylene-(meth)acrylic acid copolymer films, and ethylene-(meth)acrylic acid ester copolymer films; polyvinyl chloride films such as polyvinyl chloride films and vinyl chloride copolymer films; polyester films such as polyethylene terephthalate films and polybutylene terephthalate films; polyurethane films; polyimide films; polystyrene films; polycarbonate films; fluororesin films, etc. Furthermore, modified films such as crosslinked films and ionomer films formed by crosslinking the resins forming these films may also be used.

[0120] As the substrate (Y), one of these resin films may be used alone, or a laminated film of two or more types used in combination may be used.

[0121] Here, from the perspectives of versatility, high strength and ease of warping prevention, heat resistance, and improved laser transmittance, the resin film is preferably a polyethylene film such as a low-density polyethylene (LDPE) film, a linear low-density polyethylene (LLDPE) film, and a high-density polyethylene (HDPE) film, a polyester film such as a polyethylene terephthalate film and a polybutylene terephthalate film, or a polypropylene film. Specifically, the resin film is preferably a single-layer film having one or more layers selected from polyethylene films, polyester films, and polypropylene films, or a laminated film comprising two or more layers.

[0122] It should be noted that, from the perspective of easily ensuring high light transmittance for light of a desired wavelength, it is preferable to improve the smoothness of the first surface of the substrate (Y) (the surface opposite to the surface on which the adhesive layer (X1) is formed). Specifically, the arithmetic mean roughness Ra of the first surface of the substrate (Y) is preferably 0.01 μm to 0.8 μm. It should be noted that the arithmetic mean roughness Ra is a value measured in accordance with JIS B 0601:1994.

[0123] The substrate (Y) may contain a colorant. However, when a laser is used in the adhesion reduction step of step (S2), the content of the colorant that absorbs the laser light is preferably low from the perspective of obtaining a substrate with improved laser light transmittance. Specifically, the content of the colorant that absorbs the laser light is preferably less than 0.1% by mass, more preferably less than 0.01% by mass, even more preferably less than 0.001% by mass, based on the total amount of the substrate (Y). It is even more preferred that no colorant be present.

[0124] The thickness of the substrate (Y) is not particularly limited, but is preferably in the range of 20 μm to 450 μm, more preferably 25 μm to 400 μm.

[0125] <Adhesive Layer (X1)>

[0126] The adhesive layer (X1) only needs to contain an adhesive resin, and may contain adhesive additives such as a cross-linking agent, a tackifier, a polymerizable compound, and a polymerization initiator as needed.

[0127] The adhesive layer (X1) can be formed of an adhesive composition containing an adhesive resin.

[0128] Hereinafter, each component contained in the adhesive composition which is a material for forming the adhesive layer (X1) will be described.

[0129] (Adhesive resin)

[0130] The adhesive resin is preferably a polymer having adhesive properties alone and a weight average molecular weight (Mw) of 10,000 or more.

[0131] From the viewpoint of improving adhesive strength, the weight average molecular weight (Mw) of the adhesive resin is more preferably 10,000 to 2,000,000, further preferably 20,000 to 1,500,000, and even more preferably 30,000 to 1,000,000.

[0132] Examples of the adhesive resin include rubber-based resins such as polyisobutylene-based resins, acrylic resins, urethane resins, polyester resins, olefin-based resins, silicone-based resins, and polyvinyl ether-based resins.

[0133] These adhesive resins may be used alone or in combination of two or more.

[0134] When these adhesive resins are copolymers having two or more structural units, the form of the copolymer is not particularly limited and may be any of a block copolymer, a random copolymer, an alternating copolymer, and a graft copolymer.

[0135] The adhesive resin may be an energy-ray-curable adhesive resin having a polymerizable functional group introduced into a side chain.

[0136] Examples of the polymerizable functional group include a (meth)acryloyl group and a vinyl group.

[0137] In addition, examples of energy rays include ultraviolet rays and electron beams, and ultraviolet rays are preferred.

[0138] The content of the adhesive resin relative to the total amount of active ingredients in the adhesive composition (100% by mass) is preferably 30 to 99.99% by mass, more preferably 40 to 99.95% by mass, further preferably 50 to 99.90% by mass, further preferably 55 to 99.80% by mass, and further preferably 60 to 99.50% by mass.

[0139] In the following description of this specification, “the content of each component relative to the total amount of active ingredients in the adhesive composition” and “the content of each component in the adhesive layer formed from the adhesive composition” have the same meaning.

[0140] Here, the adhesive resin preferably contains an acrylic resin from the viewpoint of exhibiting excellent adhesive strength and suppressing the penetration of cutting water between the adhesive layer (X1) and the protective film during cutting.

[0141] The content of the acrylic resin in the adhesive resin is preferably 30 to 100 mass %, more preferably 50 to 100 mass %, further preferably 70 to 100 mass %, and even more preferably 85 to 100 mass %, relative to the total amount (100 mass %) of the adhesive resin contained in the adhesive composition.

[0142] (Acrylic resin)

[0143] Examples of acrylic resins that can be used as adhesive resins include polymers containing a structural unit derived from an alkyl (meth)acrylate having a linear or branched alkyl group and polymers containing a structural unit derived from a (meth)acrylate having a cyclic structure.

[0144] The weight average molecular weight (Mw) of the acrylic resin is preferably 100,000 to 1.5 million, more preferably 200,000 to 1.3 million, even more preferably 350,000 to 1.2 million, and even more preferably 500,000 to 1.1 million.

[0145] As the acrylic resin, an acrylic copolymer (A1) having a structural unit (a1) derived from an alkyl (meth)acrylate (a1′) (hereinafter also referred to as “monomer (a1′)”) and a structural unit (a2) derived from a functional group-containing monomer (a2′) (hereinafter also referred to as “monomer (a2′)”) is more preferred.

[0146] The number of carbon atoms of the alkyl group possessed by the monomer (a1′) is preferably 1 to 24, more preferably 1 to 12, further preferably 2 to 10, and even more preferably 4 to 8, from the viewpoint of improving the adhesive properties required as an adhesive sheet (dicing tape) and suppressing the phenomenon of cutting water penetrating between the adhesive layer (X1) and the protective film during dicing.

[0147] It should be noted that the alkyl group contained in the monomer (a1′) may be a linear alkyl group or a branched alkyl group.

[0148] Examples of the monomer (a1′) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, and stearyl (meth)acrylate.

[0149] These monomers (a1') may be used alone or in combination of two or more.

[0150] As the monomer (a1′), butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are preferred.

[0151] The content of the structural unit (a1) relative to all structural units (100% by mass) of the acrylic copolymer (A1) is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% by mass, further preferably 70 to 97.0% by mass, and even more preferably 80 to 95.0% by mass.

[0152] Examples of the functional group possessed by the monomer (a2′) include a hydroxyl group, a carboxyl group, an amino group, and an epoxy group.

[0153] That is, as a monomer (a2'), a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, etc. are mentioned, for example.

[0154] These monomers (a2') may be used alone or in combination of two or more.

[0155] Among these monomers, the monomer (a2′) is preferably a hydroxyl group-containing monomer or a carboxyl group-containing monomer.

[0156] Examples of hydroxyl group-containing monomers include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; and unsaturated alcohols such as vinyl alcohol and allyl alcohol.

[0157] Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid, and citraconic acid, and their anhydrides; 2-(acryloyloxy)ethyl succinate; and 2-carboxyethyl (meth)acrylate.

[0158] The content of the structural unit (a2) relative to the total structural units (100% by mass) of the acrylic copolymer (A1) is preferably 0.1 to 40% by mass, more preferably 0.5 to 35% by mass, further preferably 1.0 to 30% by mass, and even more preferably 3.0 to 25% by mass.

[0159] The acrylic copolymer (A1) may further have a structural unit (a3) ​​derived from another monomer (a3') other than the monomers (a1') and (a2').

[0160] In the acrylic copolymer (A1), the content of the structural units (a1) and (a2) relative to the total structural units (100% by mass) of the acrylic copolymer (A1) is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and even more preferably 95 to 100% by mass.

[0161] Examples of the monomer (a3') include olefins such as ethylene, propylene, and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; diene monomers such as butadiene, isoprene, and chloroprene; (meth)acrylates having a cyclic structure such as cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and imide (meth)acrylate; styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, (meth)acrylamide, (meth)acrylonitrile, (meth)acryloylmorpholine, and N-vinylpyrrolidone.

[0162] Moreover, the acrylic copolymer (A1) may be an energy-ray-curable acrylic copolymer having a polymerizable functional group introduced into a side chain.

[0163] Examples of the polymerizable functional group include a (meth)acryloyl group and a vinyl group.

[0164] In addition, examples of energy rays include ultraviolet rays and electron beams, and ultraviolet rays are preferred.

[0165] The polymerizable functional group can be introduced by reacting the acrylic copolymer having the structural units (a1) and (a2) with a compound having a substituent capable of bonding to the functional group of the structural unit (a2) of the acrylic copolymer and a polymerizable functional group.

[0166] As said compound, (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, glycidyl (meth)acrylate, etc. are mentioned, for example.

[0167] (cross-linking agent)

[0168] The adhesive composition preferably further contains a cross-linking agent.

[0169] This crosslinking agent reacts with the adhesive resin having a functional group, as in the above-mentioned acrylic copolymer (A1), and crosslinks the adhesive resins with the functional group serving as a crosslinking starting point.

[0170] Examples of the cross-linking agent include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, aziridine-based cross-linking agents, and metal chelate-based cross-linking agents.

[0171] These cross-linking agents may be used alone or in combination of two or more.

[0172] Among these cross-linking agents, isocyanate cross-linking agents are preferred from the viewpoints of improving cohesive strength and thus adhesive strength, and from the viewpoints of easy availability.

[0173] The content of the crosslinking agent can be appropriately adjusted depending on the number of functional groups in the adhesive resin, but is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 7 parts by mass, and even more preferably 0.05 to 5 parts by mass per 100 parts by mass of the adhesive resin having functional groups.

[0174] (Thickener)

[0175] From the viewpoint of further improving adhesive strength, the adhesive composition may further contain a tackifier.

[0176] In this specification, the "tackifier" refers to an oligomer having a weight average molecular weight (Mw) of less than 10,000 among components that auxiliary improve the adhesive strength of the adhesive resin, and is a component distinct from the adhesive resin.

[0177] The weight average molecular weight (Mw) of the tackifier is preferably 400 or more and less than 10,000, more preferably 500 to 8,000, and even more preferably 800 to 5,000.

[0178] Examples of the tackifier include rosin-based resins, terpene-based resins, styrene-based resins, C5 petroleum resins obtained by copolymerizing C5 fractions such as pentene, isoprene, piperine, and 1,3-pentadiene produced by thermal decomposition of naphtha, C9 petroleum resins obtained by copolymerizing C9 fractions such as indene and vinyltoluene produced by thermal decomposition of naphtha, and hydrogenated resins obtained by hydrogenating these resins.

[0179] The softening point of the tackifier is preferably 60 to 170°C, more preferably 65 to 160°C, and even more preferably 70 to 150°C.

[0180] In addition, in this specification, the "softening point" of a tackifier means the value measured based on JIS K 2531.

[0181] The thickener may be used alone or in combination of two or more thickeners having different softening points, structures, etc.

[0182] When two or more types of thickeners are used, it is preferred that the weighted average of the softening points of these types of thickeners fall within the above range.

[0183] The content of the tackifier relative to the total amount (100% by mass) of the active ingredients of the adhesive composition is preferably 0.01 to 65% by mass, more preferably 0.05 to 55% by mass, further preferably 0.1 to 50% by mass, further preferably 0.5 to 45% by mass, and further preferably 1.0 to 40% by mass.

[0184] (Photopolymerization initiator)

[0185] When the adhesive composition contains an energy-ray-curable adhesive resin as the adhesive resin, it is preferred that the adhesive composition further contain a photopolymerization initiator.

[0186] By containing a photopolymerization initiator, the curing reaction can be sufficiently advanced by irradiation with energy rays having relatively low energy.

[0187] Examples of the photopolymerization initiator include 1-hydroxycyclohexylphenylketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzylphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, bibenzyl, diacetyl, and 8-chloroanthraquinone.

[0188] These photopolymerization initiators may be used alone or in combination of two or more.

[0189] The content of the photopolymerization initiator is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, and even more preferably 0.05 to 2 parts by mass, relative to 100 parts by mass of the energy-ray-curable adhesive resin.

[0190] (Additives for adhesives)

[0191] The adhesive composition serving as a material for forming the adhesive layer (X1) may contain adhesive additives commonly used in adhesives in addition to the above-mentioned additives.

[0192] Examples of such adhesive additives include antioxidants, softeners (plasticizers), rust preventives, retarders, reaction accelerators (catalysts), and ultraviolet absorbers.

[0193] In addition, these adhesive additives may be used individually by 1 type, or may use 2 or more types together.

[0194] When these adhesive additives are contained, the content of each adhesive additive is preferably 0.0001 to 20 parts by mass, more preferably 0.001 to 10 parts by mass, relative to 100 parts by mass of the adhesive resin.

[0195] The adhesive composition may contain at least one of a pigment and a dye. However, when a laser is used in the adhesive strength reducing step (S2), the content of the pigment or dye that absorbs the laser light is preferably low from the viewpoint of laser light transmittance.

[0196] Specifically, the content of laser-absorbing pigments and dyes relative to the total amount of the adhesive composition is preferably less than 0.1 mass %, more preferably less than 0.01 mass %, further preferably less than 0.001 mass %, and even more preferably contains no pigments or dyes.

[0197] When laser light is used in the adhesive strength reducing step (S2), a pressure-sensitive adhesive composition that can prevent scattering of the laser light is preferred.

[0198] <Adhesive Layer (X2)>

[0199] When the PSA sheet (X) is a double-sided PSA sheet, the PSA layer (X2) of the double-sided PSA sheet only needs to contain an adhesive resin and may contain PSA additives such as a crosslinking agent, a tackifier, a polymerizable compound, and a polymerization initiator as needed.

[0200] The preferred embodiment of the composition and morphology of the adhesive layer (X2) is the same as that of the adhesive layer (X1). The compositions of the adhesive layer (X1) and the adhesive layer (X2) may be the same or different. In addition, the morphologies of the adhesive layer (X1) and the adhesive layer (X2) may be the same or different.

[0201] The thickness of each of the adhesive layer (X1) and the adhesive layer (X2) is not particularly limited, but is preferably about 1 to 50 μm, more preferably 2 to 30 μm.

[0202] The thicknesses of the adhesive layer (X1) and the adhesive layer (X2) may be the same or different.

[0203] <Peeling Material>

[0204] A release material may be further provided on the adhesive surface of either or both of the adhesive layer (X1) and the adhesive layer (X2) optionally included in the adhesive sheet (X).

[0205] As the release material, a release sheet treated on both sides or a release sheet treated on one side can be used. Examples of the release material include a release material substrate coated with a release agent.

[0206] Examples of the release material substrate include: paper such as high-quality paper, glassine paper, and kraft paper; plastic films such as polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin; and olefin resin films such as polypropylene resin and polyethylene resin.

[0207] Examples of the release agent include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins, and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins.

[0208] The thickness of the release material is not particularly limited, but is preferably 10 to 200 μm, more preferably 25 to 170 μm, and even more preferably 35 to 80 μm.

[0209] <Method for producing adhesive sheet (X)>

[0210] The method for producing the adhesive sheet (X) is not particularly limited and can be produced by a known method. For example, an organic solvent can be added to a raw material composition (hereinafter also referred to as "adhesive layer-forming composition") containing the above-mentioned components to prepare a solution of the raw material composition. This solution can be applied to a substrate (Y) by a known coating method to form a coating film, which is then dried to form the adhesive layer (X1) on the substrate (Y).

[0211] Alternatively, after forming a coating film by coating the solution on the release material using a known coating method, drying the coating film to form an adhesive layer (X1) on the release material, the substrate (Y) and the adhesive layer (X1) may be bonded together to produce an adhesive sheet (X) having a laminated structure of release material / adhesive layer (X1) / substrate (Y).

[0212] Examples of the organic solvent used include toluene, ethyl acetate, and methyl ethyl ketone.

[0213] When an organic solvent is added, the solid content concentration of the adhesive layer-forming composition solution is preferably 10 to 80% by mass, more preferably 25 to 70% by mass, and even more preferably 45 to 65% by mass.

[0214] Examples of the coating method include spin coating, spray coating, wire bar coating, knife coating, roll coating, knife roll coating, blade coating, die coating, and gravure coating.

[0215] [Protective film forming film]

[0216] The protective film-forming film is not particularly limited, but preferably contains a polymer component (B) and a curable component (C), and may further contain a colorant (D), a coupling agent (E), an inorganic filler (F), and a general additive (G).

[0217] Hereinafter, the components (B) to (G) contained in the protective film-forming film will be described.

[0218] <Polymer component (B)>

[0219] The "polymer component" refers to a compound having a weight-average molecular weight (Mw) of 20,000 or greater and at least one repeating unit. The inclusion of the polymerizable component (B) in the protective film-forming film primarily imparts flexibility and film-forming properties to the protective film-forming film, thereby improving sheet shape retention.

[0220] The weight average molecular weight (Mw) of the polymer component (B) is preferably 20,000 to 3,000,000, more preferably 50,000 to 2,000,000, and even more preferably 100,000 to 1,500,000.

[0221] The content of the polymer component (B) is preferably 5 to 50 mass %, more preferably 8 to 40 mass %, further preferably 10 to 30 mass %, and even more preferably 12 to 25 mass % relative to the total amount (100 mass %) of the protective film-forming film.

[0222] The polymer component (B) is preferably an acrylic polymer (B1), but non-acrylic polymers (B2) such as polyesters, phenoxy resins, polycarbonates, polyethers, polyurethanes, polysiloxanes, and rubber polymers other than the acrylic polymer (B1) may also be used.

[0223] These polymer components may be used alone or in combination of two or more.

[0224] (Acrylic polymer (B1))

[0225] From the viewpoint of imparting flexibility and film-forming properties to the protective film-forming film, the weight average molecular weight (Mw) of the acrylic polymer (B1) is preferably 20,000 to 3,000,000, more preferably 100,000 to 1,500,000, further preferably 150,000 to 1,200,000, and even more preferably 250,000 to 1,000,000.

[0226] From the viewpoint of the adhesion of the protective film formed from the protective film-forming film to the adherend and the viewpoint of improving the reliability of the chip with the protective film, the glass transition temperature (Tg) of the acrylic polymer (B1) is preferably -60 to 50°C, more preferably -50 to 40°C, further preferably -40 to 30°C, and even more preferably -35 to 20°C.

[0227] Examples of the acrylic polymer (B1) include polymers containing an alkyl (meth)acrylate as a main component. Specifically, an acrylic polymer containing a structural unit (b1) derived from an alkyl (meth)acrylate having an alkyl group having 1 to 18 carbon atoms is preferred. An acrylic copolymer containing the structural unit (b1) and a structural unit (b2) derived from a functional group-containing monomer is more preferred.

[0228] Component (B1) may be used alone or in combination of two or more.

[0229] When the component (B1) is a copolymer, the copolymer may be in the form of a block copolymer, a random copolymer, an alternating copolymer, or a graft copolymer.

[0230] (Structural unit (b1))

[0231] The alkyl group of the (meth)acrylate constituting the structural unit (b1) preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, and even more preferably 1 to 8 carbon atoms, from the viewpoint of imparting flexibility and film-forming properties to the protective film-forming film.

[0232] Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate.

[0233] In addition, these alkyl (meth)acrylates may be used alone or in combination of two or more.

[0234] Among these alkyl (meth)acrylates, alkyl (meth)acrylates having an alkyl group with 4 or more carbon atoms are preferred, alkyl (meth)acrylates having an alkyl group with 4 to 6 carbon atoms are more preferred, and butyl (meth)acrylate is further preferred.

[0235] The content ratio of the structural units derived from the (meth)acrylic acid alkyl ester having an alkyl group having 4 or more carbon atoms is preferably 1 to 70 mass%, more preferably 5 to 65 mass%, and even more preferably 10 to 60 mass%, relative to all structural units (100 mass%) of the acrylic polymer (B1).

[0236] From the viewpoint of improving the reliability of the chip with a protective film, an alkyl (meth)acrylate having an alkyl group having 1 to 3 carbon atoms is preferred, and methyl (meth)acrylate is more preferred.

[0237] From the above viewpoints, the content ratio of the structural units derived from the (meth)acrylate having an alkyl group having 1 to 3 carbon atoms is preferably 1 to 60 mass%, more preferably 3 to 50 mass%, and even more preferably 5 to 40 mass%, relative to the total structural units (100 mass%) of the acrylic polymer (B1).

[0238] The content of the structural unit (b1) relative to all structural units (100% by mass) of the acrylic polymer (B1) is preferably 50% by mass or more, more preferably 50 to 99% by mass, further preferably 55 to 90% by mass, and even more preferably 60 to 80% by mass.

[0239] (Structural unit (b2))

[0240] Examples of the functional group-containing monomer constituting the structural unit (b2) include hydroxyl group-containing monomers, carboxyl group-containing monomers, epoxy group-containing monomers, amino group-containing monomers, cyano group-containing monomers, ketone group-containing monomers, monomers having a nitrogen atom-containing ring, and alkoxysilyl group-containing monomers.

[0241] These functional group-containing monomers may be used alone or in combination of two or more.

[0242] Among these functional group-containing monomers, hydroxyl group-containing monomers are preferred.

[0243] Examples of the hydroxyl group-containing monomer include those exemplified in the description of the hydroxyl group-containing monomer for the pressure-sensitive adhesive layer (X1), and 2-hydroxyethyl (meth)acrylate is preferred.

[0244] As the carboxyl group-containing monomer, those exemplified as the carboxyl group-containing monomer in the adhesive layer (X1) can be mentioned.

[0245] By using a carboxyl group-containing monomer, a carboxyl group can be introduced into the acrylic polymer (B1). When the protective film-forming film contains an energy ray-curable component as the curable component (C), the compatibility between the component (C) and the component (B) is improved.

[0246] When an epoxy thermosetting component is used as the curable component (C) described below, the content of the structural unit derived from the carboxyl group-containing monomer is preferably low because the carboxyl group reacts with the epoxy group in the epoxy thermosetting component.

[0247] When an epoxy thermosetting component is used as the curable component (C), the content of the structural unit derived from the carboxyl group-containing monomer is preferably 0 to 10 mass %, more preferably 0 to 5 mass %, even more preferably 0 to 2 mass %, and even more preferably 0 mass %, relative to all structural units (100 mass %) of the acrylic polymer (A1).

[0248] Examples of the epoxy group-containing monomer include epoxy group-containing (meth)acrylates and non-acrylic epoxy group-containing monomers.

[0249] Examples of the epoxy group-containing (meth)acrylate include glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and 3-epoxycyclo-2-hydroxypropyl (meth)acrylate.

[0250] Moreover, as a non-acrylic epoxy group-containing monomer, glycidyl crotonate, allyl glycidyl ether, etc. are mentioned, for example.

[0251] Among these, epoxy group-containing (meth)acrylate is preferred, and glycidyl (meth)acrylate is more preferred.

[0252] These functional group-containing monomers may be used alone or in combination of two or more.

[0253] From the viewpoint of further improving the sublimation properties of the protective film, the content of the structural units derived from the epoxy-group-containing monomer is preferably 1 to 30% by mass, more preferably 5 to 27% by mass, and even more preferably 10 to 24% by mass, relative to the total structural units (100% by mass) of the acrylic polymer (B1).

[0254] The content of the structural unit (b2) relative to all structural units (100% by mass) of the acrylic polymer (B1) is preferably 1 to 50% by mass, more preferably 5 to 45% by mass, further preferably 10 to 40% by mass, and even more preferably 20 to 40% by mass.

[0255] (Structural units derived from other monomers)

[0256] In addition, the acrylic polymer (B1) may have a structural unit derived from another monomer in addition to the above-mentioned structural units (b1) and (b2) within a range not impairing the effects of the present invention.

[0257] Examples of other monomers include vinyl acetate, styrene, ethylene, and α-olefins.

[0258] (Non-acrylic resin (B2))

[0259] The protective film-forming film may contain a non-acrylic resin (B2) as a resin component other than the acrylic polymer (B1), as needed.

[0260] Examples of the non-acrylic resin (B2) include polyester, phenoxy resin, polycarbonate, polyether, polyurethane, polysiloxane, and rubber-based polymers.

[0261] These resins may be used alone or in combination of two or more.

[0262] The weight average molecular weight of the non-acrylic resin (B2) is preferably 20,000 or more, more preferably 20,000 to 100,000, and even more preferably 20,000 to 80,000.

[0263] The non-acrylic resin (B2) may be used alone, but its combined use with the acrylic polymer (B1) facilitates interlayer delamination when the pressure-sensitive adhesive sheet and the protective film-forming film are laminated, thereby suppressing the generation of voids.

[0264] When the non-acrylic resin (B2) is used in combination with the acrylic polymer (B1), from the above viewpoint, the mass ratio of the non-acrylic resin (B2) to the acrylic polymer (B1) [(B2) / (B1)] is preferably 1 / 99 to 60 / 40, more preferably 1 / 99 to 30 / 70.

[0265] It should be noted that when the structural units constituting the acrylic polymer (B1) include structural units derived from epoxy-containing monomers, the acrylic polymer (B1) and the phenoxy resin having an epoxy group are thermosetting, but they are not the curable component (C) and are considered to be included in the concept of the polymer component (B).

[0266] <Curing Component (C)>

[0267] The curable component (C) plays a role in curing the protective film-forming film to form a hard protective film, and is a compound having a weight average molecular weight of less than 20,000.

[0268] As the curable component (C), it is preferred to use a thermosetting component (C1) and / or an energy ray curable component (C2). From the viewpoint of sufficient progress of the curing reaction and cost reduction, it is more preferred to use at least the thermosetting component (C1).

[0269] As the thermosetting component (C1), it is preferred that the thermosetting component (C1) contain at least a compound having a functional group that reacts by heating.

[0270] The energy ray-curable component (C2) contains a compound (C21) having a functional group that reacts upon irradiation with energy rays, and is polymerized and cured upon irradiation with energy rays such as ultraviolet rays and electron beams.

[0271] The functional groups of these curable components react with each other to form a three-dimensional network structure, thereby achieving curing.

[0272] The weight average molecular weight (Mw) of the curable component (C) is preferably less than 20,000, more preferably 10,000 or less, and even more preferably 100 to 10,000, from the viewpoint of suppressing the viscosity of the composition forming the protective film-forming film and improving workability by using it in combination with the component (B).

[0273] (Thermosetting component (C1))

[0274] As the thermosetting component (C1), an epoxy-based thermosetting component is preferred.

[0275] The epoxy-based thermosetting component is preferably used in combination with a thermosetting agent (C12) and a compound (C11) having an epoxy group.

[0276] Examples of the compound (C11) having an epoxy group (hereinafter also referred to as "epoxy compound (C11)") include: polyfunctional epoxy resins, bisphenol A diglycidyl ether and its hydrogenated product, o-cresol novolac epoxy resin, dicyclopentadiene epoxy resin, biphenyl epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, phenylene skeleton epoxy resin, and other epoxy compounds having two or more functional groups in the molecule.

[0277] These epoxy compounds (C11) may be used alone or in combination of two or more.

[0278] The content of the epoxy compound (C11) is preferably 1 to 500 parts by mass, more preferably 3 to 300 parts by mass, further preferably 10 to 150 parts by mass, and even more preferably 20 to 120 parts by mass, relative to 100 parts by mass of the component (B).

[0279] (Thermosetting agent (C12))

[0280] The thermosetting agent (C12) functions as a curing agent for the epoxy compound (C11).

[0281] As the thermosetting agent, a compound having two or more functional groups reactive with an epoxy group in one molecule is preferred.

[0282] Examples of the functional group include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and acid anhydride groups (acid anhydride structures). Among these functional groups, phenolic hydroxyl groups, amino groups, and acid anhydride groups are preferred, phenolic hydroxyl groups or amino groups are more preferred, and amino groups are further preferred.

[0283] Examples of the phenolic thermosetting agent having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenol, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, XYLOK-type phenolic resins, and aralkylphenolic resins.

[0284] Examples of the amine-based thermosetting agent having an amino group include dicyandiamide (DICY) and the like.

[0285] These thermosetting agents (C12) may be used alone or in combination of two or more.

[0286] The content of the thermosetting agent (C12) is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass, relative to 100 parts by mass of the epoxy compound (C11).

[0287] (Curing accelerator (C13))

[0288] In order to adjust the thermal curing speed of the protective film forming film, a curing accelerator (C13) may be used. The curing accelerator (C13) is preferably used in combination with the epoxy compound (C11) as the thermosetting component (C1).

[0289] Examples of the curing accelerator (C13) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphine tetraphenylborate and triphenylphosphine tetraphenylborate.

[0290] These curing accelerators (C13) may be used alone or in combination of two or more.

[0291] From the viewpoint of improving the adhesion of the protective film formed by the protective film-forming film and the viewpoint of improving the reliability of the chip with the protective film, the content of the curing accelerator (C13) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 6 parts by mass, and even more preferably 0.3 to 4 parts by mass relative to 100 parts by mass of the total amount of the epoxy compound (C11) and the thermosetting agent (C12).

[0292] (Energy ray curable component (C2))

[0293] As the energy ray-curable component (C2), a compound (C21) having a functional group that reacts upon irradiation with energy rays may be used alone, but it is preferred to use the compound (C21) in combination with a photopolymerization initiator (C22).

[0294] (Compound (C21) having a functional group that reacts upon energy ray irradiation)

[0295] Examples of the compound (C21) having a functional group that reacts upon exposure to energy rays (hereinafter also referred to as “energy ray-reactive compound (C21)”) include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, oligoester acrylates, urethane acrylate oligomers, epoxy acrylates, polyether acrylates, and itaconic acid oligomers.

[0296] These energy ray reactive compounds (C21) may be used alone or in combination of two or more.

[0297] The weight average molecular weight (Mw) of the energy ray reactive compound (C21) is preferably 100 to 30,000, more preferably 300 to 10,000.

[0298] The content of the energy ray-reactive compound (C21) is preferably 1 to 1,500 parts by mass, more preferably 3 to 1,200 parts by mass, relative to 100 parts by mass of the component (B).

[0299] (Photopolymerization initiator (C22))

[0300] By using the energy ray reactive compound (C21) in combination with the photopolymerization initiator (C22), the polymerization curing time can be shortened, and curing of the protective film-forming film can be advanced even with a reduced light irradiation dose.

[0301] As the photopolymerization initiator (C22), those mentioned above can be cited.

[0302] From the viewpoint of sufficiently advancing the curing reaction and suppressing the generation of residues, the content of the photopolymerization initiator (C22) is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the energy ray-reactive compound (C21).

[0303] The content of component (C) is preferably 5 to 50 mass %, more preferably 8 to 40 mass %, further preferably 10 to 30 mass %, and even more preferably 12 to 25 mass % relative to the total amount (100 mass %) of the protective film-forming film.

[0304] It should be noted that the content of component (C) refers to the total content of the thermosetting component (C1) containing the above-mentioned epoxy compound (C11), the thermosetting agent (C12), and the curing accelerator (C13), and the energy ray-curable component (C2) containing the energy ray-reactive compound (C21) and the photopolymerization initiator (C22).

[0305] <Colorant (D)>

[0306] The protective film-forming film preferably further contains a colorant (D).

[0307] By including a colorant (D) in the protective film-forming film, when a laser is used in the adhesion reduction step (S2), the type and content of the colorant (D) can be selected to increase the laser absorptivity of the protective film, thereby improving the sublimation properties of the protective film. In other words, by including a colorant (D) that absorbs laser light in the protective film formed from the protective film-forming film, the sublimation properties of the protective film can be improved.

[0308] As the colorant (D), one or more selected from pigments and dyes can be used.

[0309] The pigment can be either organic or inorganic.

[0310] Examples of the dye include basic dyes, acid dyes, disperse dyes, and direct dyes.

[0311] Examples of the black pigment include carbon black, copper oxide, ferrosoferric oxide, manganese dioxide, aniline black, and activated carbon.

[0312] Examples of yellow pigments include chrome yellow, zinc yellow, cadmium yellow, iron oxide yellow, mineral fast yellow, nickel titanium yellow, Naples yellow, naphthol yellow S, Hansa yellow, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and lemon yellow lake.

[0313] Examples of the orange pigment include red chrome yellow, molybdenum orange, Pigment Orange GTR, pyrazolone orange, sulfur-resistant orange, Indanthrene Brilliant Orange RK, benzidine orange G, and Indanthrene Brilliant Orange GKM.

[0314] Examples of red pigments include red earth, cadmium red, red lead, mercuric sulfide, cadmium, Permanent Red 4R, Lithol Red, pyrazolone red, Watching Red, calcium salts, Red Lake D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, and Brilliant Carmine 3B.

[0315] Examples of the violet pigment include manganese violet, permanent violet B, and methyl violet lake.

[0316] Examples of the blue pigment include Prussian blue, cobalt blue, basic blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, fast sky blue, and Indanth Blue BC.

[0317] Examples of the green pigment include chrome green, chromium oxide, Pigment Green B, malachite green lake, and Final Yellow Green G.

[0318] Examples of the dye include nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

[0319] Among them, in the adhesive force reduction step of step (S2), black pigments and black dyes are preferably used from the viewpoint of easily improving the laser absorptivity in a wide wavelength range. Among black pigments, carbon black is more preferably used from the viewpoint of improving the reliability of semiconductor chips. From the same viewpoint, aniline black is more preferably used among black dyes.

[0320] The axis colorant (D) may be used alone or in combination of two or more.

[0321] The content of the colorant (D) is preferably 0.1 to 30 mass %, more preferably 0.5 to 25 mass %, further preferably 1.0 to 15 mass %, and even more preferably 1.2 to 5 mass % relative to the total amount (100 mass %) of the protective film-forming film.

[0322] <Coupling Agent (E)>

[0323] The protective film-forming film preferably further contains a coupling agent (E).

[0324] The inclusion of a coupling agent (E) allows the polymer component in the protective film-forming film to bond with the surface of the semiconductor chip or filler as an adherend, thereby improving adhesion and cohesion. Furthermore, the water resistance of the protective film formed from the protective film-forming film can be improved without compromising the heat resistance of the protective film.

[0325] The coupling agent (E) is preferably a compound that reacts with the functional groups of the component (B) and the component (C), and more preferably a silane coupling agent.

[0326] Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane.

[0327] These coupling agents (E) may be used alone or in combination of two or more.

[0328] As the coupling agent (E), an oligomer type coupling agent is preferred.

[0329] The molecular weight of the coupling agent (E), including oligomer-type coupling agents, is preferably 100 to 15,000, more preferably 150 to 10,000, further preferably 200 to 5,000, further preferably 250 to 3,000, and still further preferably 350 to 2,000.

[0330] The content of the coupling agent (E) is preferably 0.01 to 10 mass %, more preferably 0.05 to 7 mass %, further preferably 0.10 to 4 mass %, and even more preferably 0.15 to 2 mass % relative to the total amount (100 mass %) of the protective film-forming film.

[0331] <Inorganic Filler (F)>

[0332] The protective film-forming film preferably further contains an inorganic filler (F).

[0333] The inclusion of the inorganic filler (F) allows the thermal expansion coefficient of the protective film after curing of the protective film-forming film to be adjusted to an appropriate range. This optimizes the thermal expansion coefficient of the cured protective film relative to the semiconductor chip, thereby improving the reliability of the semiconductor device. Furthermore, the moisture absorption rate of the cured protective film can be reduced.

[0334] Examples of the inorganic filler (F) include powders of silica, alumina, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride, and the like, spherical beads thereof, single crystal fibers, and glass fibers.

[0335] These inorganic fillers (F) may be used alone or in combination of two or more.

[0336] Among these, silica or alumina is preferred.

[0337] The average particle size of the inorganic filler (F) is preferably 10 nm to 50 μm, more preferably 20 nm to 30 μm, and even more preferably 30 nm to 10 μm, from the viewpoint of improving the glossiness value of the protective film formed from the protective film-forming film.

[0338] In addition, in this invention, the average particle diameter of an inorganic filler (F) is the value measured using the laser diffraction scattering type particle size distribution measuring apparatus.

[0339] The content of the inorganic filler (F) is preferably 25 to 80 mass %, more preferably 30 to 70 mass %, further preferably 40 to 65 mass %, and even more preferably 45 to 60 mass % relative to the total amount (100 mass %) of the protective film-forming film.

[0340] <General Additives (G)>

[0341] In addition to the above-mentioned additives, various additives may be blended into the protective film-forming film as needed.

[0342] Examples of the various additives include a cross-linking agent, a leveling agent, a plasticizer, an antistatic agent, an antioxidant, an ion scavenger, a getter, and a chain transfer agent.

[0343] <Method for Producing Protective Film-Forming Film>

[0344] The method for producing the protective film-forming film is not particularly limited and can be produced by a known method. For example, an organic solvent can be added to a raw material composition containing the above-mentioned components (hereinafter also referred to as a "protective film-forming composition") to prepare a solution of the protective film-forming composition. This solution can be applied to the release sheet by a known coating method to form a coating film, and then dried to form a protective film-forming film on the release sheet.

[0345] Examples of the organic solvent used include toluene, ethyl acetate, and methyl ethyl ketone.

[0346] When an organic solvent is added, the solid content concentration of the solution of the protective film-forming composition is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, and even more preferably 30 to 65% by mass.

[0347] Examples of the coating method include spin coating, spray coating, wire bar coating, knife coating, roll coating, knife roll coating, blade coating, die coating, and gravure coating.

[0348] The protective film-forming film may be a single layer or may have a multilayer structure of two or more layers.

[0349] The thickness of the protective film forming film is not particularly limited, but is preferably 3 to 300 μm, more preferably 5 to 250 μm, and even more preferably 7 to 200 μm. When the protective film forming film has a multilayer structure, the total thickness (the total thickness of each layer) is also preferably within this range.

[0350] <Method for Manufacturing a Protective Film-Forming Laminated Body>

[0351] There are no particular restrictions on the method for producing the protective film-forming laminate comprising a laminate structure of a protective film-forming film and an adhesive sheet (X), and the laminate can be produced by a known method.

[0352] First, as described in the method for producing a protective film-forming film, a protective film-forming film is formed on a release sheet. Next, the adhesive layer (X1) of an adhesive sheet (X) is bonded to the protective film-forming film formed on the release sheet, thereby producing a protective film-forming laminate having a laminate structure of release sheet / protective film-forming film / adhesive layer (X1) or release sheet / protective film-forming film / adhesive layer (X1) / substrate (Y).

[0353] [Desirable method for picking up semiconductor chips with protective films]

[0354] The method for picking up the semiconductor chip with a protective film after the adhesive strength with the adhesive layer (X1) is reduced by step (S2) is not particularly limited, and examples thereof include a method of pushing upward from the bottom side with a needle or the like through the adhesive sheet (X) and picking up with a vacuum collet or the like.

[0355] Here, in the manufacturing method of one embodiment of the present invention, it is preferable to pick up the semiconductor chip with a protective film after the adhesive force with the pressure-sensitive adhesive layer (X1) is reduced in step (S2) by the following method.

[0356] That is, it is preferable to perform the following step (SP1) before or after the step (S2), and to perform the following step (SP2) after the following step (SP1) and after the step (S2).

[0357] Step (SP1): a step of laminating the plurality of semiconductor chips with protective films to the adhesive layer (Z1) of a transfer sheet (Z) having an adhesive layer (Z1) with the side opposite to the protective film side as a laminating surface, and laminating the adhesive layer (X1) and the transfer sheet (Z) with the plurality of semiconductor chips with protective films interposed therebetween;

[0358] Step (SP2): a step of separating the transfer sheet (Z) from the adhesive layer (X1), peeling only the partially protected semiconductor chips from the adhesive layer (X1), and transferring the partially protected semiconductor chips to the transfer sheet (Z).

[0359] In the following description, this method is also referred to as a "transfer method."

[0360] In step (SP1), if Figure 5 As shown, a plurality of semiconductor chips 11 with protective films (including a portion of semiconductor chips 11a with protective films that need to be peeled off) are bonded to the adhesive layer (Z1) of a transfer sheet (Z) having an adhesive layer (Z1) with the side opposite to the protective film side as the bonding surface, and the adhesive layer (X1) and the transfer sheet (Z) are stacked with the plurality of semiconductor chips 11 with protective films therebetween.

[0361] <Transfer Sheet (Z)>

[0362] The transfer sheet (Z) has a laminated structure of a substrate (Y') and an adhesive layer (Z1).

[0363] The substrate (Y') may be the same as those exemplified as the substrate (Y) of the pressure-sensitive adhesive sheet (X), and the thickness thereof is also the same as that of the substrate (Y).

[0364] Moreover, the same ones as those exemplified as the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (X) can also be used as the pressure-sensitive adhesive layer (Z1).

[0365] Step (SP1) may be performed before or after step (S2). It can be performed at any time without affecting the adhesive strength reduction step in step (S2).

[0366] Then, step (S2) is performed, in which the adhesive force between the semiconductor chip 11a with the protective film and the adhesive layer (X1) is reduced. Figure 5 As shown, the transfer sheet (Z) is separated from the adhesive sheet (X). This allows only a portion of the semiconductor chips 11a with protective films to be peeled off from the adhesive sheet (X) and a portion of the semiconductor chips 11a with protective films to be transferred to the transfer sheet (Z).

[0367] Here, the transfer method is not limited to the above method. For example, step (S2) can also be implemented, in which a porous stage is arranged in contact with the surface of a plurality of semiconductor chips 11 with protective films that is opposite to the protective film side in a state where the adhesion between a portion of the semiconductor chips 11a with protective films and the adhesive layer (X1) is reduced, so that a portion of the semiconductor chips 11a with protective films are adsorbed and transferred to the porous stage. Adsorption by the porous stage can be selectively performed only on a portion of the semiconductor chips 11a with protective films after the adhesion is reduced, or it can be performed on the entire surface of the adhesive layer (X1). In the case of adsorption by the porous stage on the entire surface of the adhesive layer (X1), the adhesive layer (X1) adsorbed on the porous stage can be separated from the porous stage, so that only a portion of the semiconductor chips 11a with protective films after the adhesion is reduced can be adsorbed and transferred to the porous stage. It should be noted that, from the perspective of transferring the semiconductor chip 11a with a protective film by attracting the entire surface with a relatively weak force, whereby only the portion of the semiconductor chip 11a with a protective film whose adhesive strength to the adhesive layer (X1) has been reduced is adsorbed, the average pore diameter of the porous stage used in this case is preferably 60 μm or less, more preferably 55 μm or less. Furthermore, the porosity is preferably 30% to 60%, more preferably 45% to 60%.

[0368] In addition, for example, a process (S2) can also be implemented, in which an electrostatic chuck is arranged in a manner that contacts the surface of a plurality of semiconductor chips 11 with protective films that is opposite to the protective film side in a state where the adhesion between a portion of the semiconductor chips 11a with protective films and the adhesive layer (X1) is reduced, thereby holding and transferring a portion of the semiconductor chips 11a with protective films to the electrostatic chuck. Holding by the electrostatic chuck can be selectively performed only on a portion of the semiconductor chips 11a with protective films after the adhesion is reduced, or it can be performed on the entire surface of the adhesive layer (X1). In the case of holding the entire surface of the adhesive layer (X1) by the electrostatic chuck, the adhesive layer (X1) held by the electrostatic chuck can be separated from the electrostatic chuck, thereby holding and transferring only a portion of the semiconductor chips 11a with protective films after the adhesion is reduced to the electrostatic chuck. It should be noted that at this time, from the perspective of holding the entire surface with a weaker force and only holding and transferring a portion of the semiconductor chip 11a with a protective film whose bonding force with the adhesive layer (X1) is reduced, an adhesive sheet formed by laminating a base material and an adhesive layer can be pasted on the electrostatic chuck as a buffer material to weaken the holding force.

[0369] [Method for manufacturing a semiconductor chip with a protective film]

[0370] The method for manufacturing a semiconductor chip with a protective film according to one embodiment of the present invention includes the step of performing the peeling method according to the present invention or the peeling method according to one embodiment of the present invention including steps ( S1 ) and ( S2 ).

[0371] In particular, the method for manufacturing a semiconductor chip with a protective film of the present invention is preferred because it can efficiently manufacture a semiconductor chip with a protective film from a semiconductor wafer with a protective film by including the step of implementing a peeling method of one embodiment of the present invention that sequentially includes steps (S1-1) to (S1-2).

[0372] In addition, by also including step (S1) and sequentially including steps (S1-1) to (S1-2), and implementing the above-mentioned method for manufacturing a semiconductor chip with a protective film, a semiconductor chip with a protective film can be efficiently manufactured from a semiconductor wafer, which is preferred.

[0373] [Method for Manufacturing a Semiconductor Device Including a Semiconductor Chip with a Protective Film]

[0374] In this specification, a "semiconductor device" refers to any device that can be used for a processor, a memory, a sensor, etc. and can function by utilizing semiconductor characteristics.

[0375] A method for manufacturing a semiconductor device including a semiconductor chip with a protective film according to one embodiment of the present invention includes the following steps: implementing the stripping method of the present invention including steps (S1) and (S2) or the stripping method of one embodiment of the present invention. Therefore, only a portion of the semiconductor chips with a protective film among a plurality of semiconductor chips with a protective film can be supplied to the processing step of the semiconductor device. Specifically, only a portion of the semiconductor chips with a protective film among a plurality of semiconductor chips with a protective film can be supplied to the step of assembling in the semiconductor device. For example, only good semiconductor chips with a protective film can be selectively supplied to the step of assembling in the semiconductor device, etc., thereby contributing to an improvement in the yield of the semiconductor device.

[0376] Example

[0377] The present invention will be described in detail with reference to the following embodiments, but the present invention is not limited to the following embodiments.

[0378] Ten semiconductor chips with protective films (chip size: 1 mm × 1 mm, chip thickness: 200 μm, protective film thickness: 25 μm) were arranged in series on the adhesive layer (X1) of the adhesive sheet (X) at a chip interval of 30 μm, and the chips were bonded with the protective film side as the bonding surface to prepare an adhesive sheet (X) having a plurality of semiconductor chips with protective films bonded thereto.

[0379] The adhesive sheet (X) used was a dicing tape having an adhesive layer (X1) laminated on a substrate (Y). The arithmetic mean roughness Ra of the surface of the substrate (Y) opposite to the surface on which the adhesive layer (X1) was formed was 0.1 μm.

[0380] Cutting tape (Adwill D-456H, manufactured by Lintec Co., Ltd.)

[0381] The protective film forming film and curing conditions for forming the protective film of the semiconductor chip with a protective film are as follows.

[0382] Protective film forming film: ADWILL LC2850 (25)

[0383] Curing conditions: 130°C, 2 hours

[0384] The protective film-forming film contains carbon black, and the protective film formed by curing the protective film-forming film can absorb laser light described later.

[0385] One semiconductor chip with a protective film in the adhesive sheet (X) on which a plurality of semiconductor chips with protective films are bonded is irradiated with laser light from the substrate (Y) side. The irradiation conditions are as follows.

[0386] (Laser irradiation conditions)

[0387] Laser irradiation device: EO Technics CSM2000, green solid-state laser (wavelength: 532 nm)

[0388] Frequency: 20,000Hz~25,000Hz

[0389] Scanning speed: 100mm / s

[0390] Output: 0.12W~0.82W

[0391] Beam diameter: 35μm

[0392] (Experimental results)

[0393] When laser light was irradiated from the substrate (Y) side toward one of the semiconductor chips with protective films in an adhesive sheet (X) having a plurality of semiconductor chips with protective films bonded thereto, visual observation from the substrate (Y) side revealed the formation of air entrapments at the interface between the semiconductor chip with protective films and the adhesive layer (X1). This indicates that a significant reduction in the adhesive strength to the adhesive layer (X1) was achieved only for this one semiconductor chip with protective films. On the other hand, the remaining semiconductor chips with protective films did not form air entrapments at their interfaces with the adhesive layer (X1), and their adhesive strength to the adhesive layer (X1) did not decrease, maintaining a secure bond to the adhesive layer (X1).

Claims

1. A method for peeling a semiconductor chip with a protective film, comprising the following steps (S1) and (S2): Step (S1): a step of laminating a plurality of semiconductor chips with protective films to the adhesive layer X1 with the protective film side as the laminating surface; Step (S2): a step of causing at least a portion of the protective film of some of the plurality of semiconductor chips with protective films to sublime to generate gas, thereby reducing the adhesive force between the semiconductor chips with protective films and the adhesive layer X1. The protective film of the semiconductor chip with a protective film is a protective film capable of absorbing laser light, The step (S2) is performed by irradiating at least a portion of the protective film of the partially protective film-attached semiconductor chip with the laser beam.

2. The stripping method according to claim 1, wherein: The step (S1) includes the following steps (S1-1) to (S1-2) in sequence. Step (S1-1): a step of laminating a semiconductor wafer with a protective film to the adhesive layer X1 with the protective film side as the laminating surface; Step (S1-2): a step of dicing the semiconductor wafer with a protective film to obtain the plurality of semiconductor chips with a protective film.

3. The stripping method according to claim 2, wherein: The semiconductor wafer with a protective film in the step (S1-1) is obtained by bonding a protective film-forming film to a semiconductor wafer and then curing the protective film-forming film.

4. The stripping method according to claim 2, wherein: The step (S1-1) is performed as follows: a protective film-forming film is stacked on the adhesive layer X1 of the adhesive sheet X having the adhesive layer X1 to obtain a protective film-forming laminate, a semiconductor wafer is bonded to the protective film-forming film side of the protective film-forming laminate, and then the protective film-forming film is cured.

5. The stripping method according to claim 4, wherein: The adhesive sheet X is a dicing tape.

6. The peeling method according to any one of claims 1 to 5, wherein: The following step (SP1) is performed before or after the step (S2), and the following step (SP2) is performed after the following step (SP1) and after the step (S2). Step (SP1): a step of laminating the plurality of semiconductor chips with protective films with the surface opposite to the protective film side thereof to the adhesive layer Z1 of a transfer sheet Z having an adhesive layer Z1, and laminating the adhesive layer X1 and the transfer sheet Z with the plurality of semiconductor chips with protective films interposed therebetween; Step (SP2): a step of separating the transfer sheet Z from the adhesive layer X1, peeling only the partially protected semiconductor chips from the adhesive layer X1, and transferring the partially protected semiconductor chips to the transfer sheet Z.

7. A method for manufacturing a semiconductor chip with a protective film, comprising: The process of carrying out the method according to any one of claims 1 to 6.

8. A method for manufacturing a semiconductor device including a semiconductor chip with a protective film, comprising: The process of carrying out the method according to any one of claims 1 to 6.

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