KR102918831B1 - Method for removing a semiconductor chip with a protective film attached - Google Patents

Abstract

The present invention relates to a method for peeling off a semiconductor chip with a protective film, comprising: a step (S1): a step of sticking a plurality of semiconductor chips with a protective film to an adhesive layer (X1) with the protective film side as an adhesive surface; and a step (S2): a step of sublimating at least a part of the protective film of some semiconductor chips with a protective film among the plurality of semiconductor chips with a protective film to generate a gas and reducing the adhesive force between the semiconductor chips with a protective film and the adhesive layer (X1); a method for manufacturing a semiconductor chip with a protective film, comprising a step of performing the method for peeling off 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 performing the method for peeling off a semiconductor chip with a protective film.

Description

Method for removing a semiconductor chip with a protective film attached

The present invention relates to a method for peeling off a semiconductor chip with a protective film attached.

Recently, semiconductor devices have been manufactured using a so-called face-down mounting method. In this method, semiconductor chips with electrodes, such as bumps, on their circuit surfaces are used, and these electrodes are bonded to the substrate. Therefore, the surface of the semiconductor chip opposite the circuit surface (hereinafter referred to as the "back side of the semiconductor chip") may be exposed. This exposed back side of the semiconductor chip is protected by a protective film primarily composed of organic materials, and is sometimes mounted in a semiconductor device as a semiconductor chip with a protective film.

A semiconductor chip with a protective film is obtained by dicing a semiconductor wafer with a protective film into individual pieces. Typically, dicing of a semiconductor wafer with a protective film is performed with the protective film side of the wafer attached to an adhesive layer. Therefore, the semiconductor chip with a protective film obtained after dicing is still attached to the adhesive layer. When manufacturing a semiconductor device, the semiconductor chip with a protective film is peeled from the adhesive layer and provided to the next process.

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

Japanese Patent Publication No. 2001-131507

The heat-peelable adhesive sheet described in Patent Document 1 is generally used in a manner in which the adhesive strength with an adherend is reduced across the entire surface of the adhesive layer by heat treatment. In short, it is used in a manner in which the adherend is peeled off en masse from the adhesive layer.

However, there are cases where it is desired to selectively peel off only some of the adherends from the adhesive layer, rather than peeling them all at once. For example, when the adherends are semiconductor chips with protective films, there are cases where it is desired to provide only some of the semiconductor chips with protective films among the plurality of semiconductor chips with protective films attached to the adhesive layer to the next process. In such cases, if the adhesive strength with the semiconductor chips with protective films is reduced over the entire surface of the adhesive layer, there is a problem that when only some of the semiconductor chips with protective films are selectively picked up and moved, vibrations, etc. that occur may cause the remaining semiconductor chips with protective films that are not picked up to misalign or peel off from the adhesive layer.

Therefore, the present invention aims to provide a method for peeling off a semiconductor chip with a protective film attached, which can selectively reduce the adhesive strength with an adhesive layer for only some of the semiconductor chips with a protective film attached among a plurality of semiconductor chips with a protective film attached attached to an adhesive layer.

After careful consideration, the inventors of the present invention have discovered that the above-mentioned problem can be solved by actively utilizing the protective film provided on a semiconductor chip with a protective film attached. Specifically, the inventors have discovered that the problem can be solved by sublimating at least a portion of the protective film of the semiconductor chip with a protective film to be peeled, generating gas and reducing the adhesive strength with the adhesive layer. After further investigation, the inventors have completed the present invention.

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

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

·Process (S1): A process of attaching a plurality of semiconductor chips with protective films to an adhesive layer (X1) with the protective film side as the bonding surface.

·Process (S2): A process of generating gas by sublimating at least a part of the protective film of some of the protective film-attached semiconductor chips among the plurality of protective film-attached semiconductor chips, and reducing the adhesive strength between some of the protective film-attached semiconductor chips and the adhesive layer (X1).

[2] The above process (S1) is a peeling method described in [1], which includes the following processes (S1-1) to (S1-2) in this order.

·Process (S1-1): A process of attaching a semiconductor wafer with a protective film to an adhesive layer (X1) with the protective film side as the attachment surface.

·Process (S1-2): A process of dicing the semiconductor wafer with the protective film attached to obtain the plurality of semiconductor chips with the protective film attached.

[3] The peeling method described in [2] above, wherein the semiconductor wafer with the protective film attached in the above process (S1-1) is obtained by bonding the protective film forming film to the semiconductor wafer and then curing the protective film forming film.

[4] The peeling method described in [2] above, wherein the process (S1-1) is performed by bonding a semiconductor wafer to the protective film-forming film side of a protective film-forming laminate in which a protective film-forming film is laminated on the adhesive layer (X1) of the adhesive sheet (X) having the adhesive layer (X1), and then curing the protective film-forming film.

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

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

The peeling method according to any one of [1] to [5], wherein the above process (S2) is performed by irradiating the laser light to at least a part of the protective film of the semiconductor chip having the protective film attached thereto.

[7] A peeling method according to any one of [1] to [6], wherein the following process (SP1) is performed before or after the above process (S2), and the following process (SP2) is performed after the below process (SP1) and also after the above process (S2).

·Process (SP1): A process of laminating the adhesive layer (Z1) of the transfer sheet (Z) having the adhesive layer (Z1) with the surface opposite to the protective film side of the plurality of protective film-attached semiconductor chips as the bonding surface, and laminating the adhesive layer (X1) and the transfer sheet (Z) with the plurality of protective film-attached semiconductor chips interposed therebetween.

·Process (SP2): A process of separating the transfer sheet (Z) and the adhesive layer (X1), peeling only the semiconductor chips with a protective film attached thereto from the adhesive layer (X1), and transferring the semiconductor chips with a protective film attached thereto onto the transfer sheet (Z).

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

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

According to the present invention, it is possible to provide a method for peeling off a semiconductor chip with a protective film attached, which can selectively reduce the adhesive strength with an adhesive layer for only some of the semiconductor chips with a protective film attached among a plurality of semiconductor chips with a protective film attached attached to an adhesive layer.

FIG. 1 is a drawing showing an example of a process (S1) of the peeling method of the present invention, (A) is a top view, and (B-1) and (B-2) are schematic cross-sectional views.
FIG. 2 is a schematic cross-sectional view showing an example of steps (S1-1) to (S1-2) of a peeling method according to one embodiment of the present invention.
Figure 3 is a schematic cross-sectional view showing an example of a process (S2) of the peeling method of the present invention.
Figure 4 is a schematic cross-sectional view showing the course of adhesive strength deterioration by enlarging the dotted line area of Figure 3.
Figure 5 is a schematic cross-sectional view showing an example of steps (SP1) to (SP2) of a peeling method according to one embodiment of the present invention.

In the present invention, “active ingredient” refers to a component excluding a dilution solvent among the components included in the target composition.

In addition, the mass average molecular weight (Mw) is a value converted to standard polystyrene measured by the gel permeation chromatography (GPC) method, and is specifically a value measured based on the method described in the examples.

Also, “(meth)acrylic acid” refers to both “acrylic acid” and “methacrylic acid,” and other similar terms are the same.

In addition, for a preferred numerical range (e.g., a range of content, etc.), the lower and upper limits described stepwise can be independently combined. For example, from the description “preferably 10 to 90, more preferably 30 to 60,” “preferable lower limit (10)” and “more preferable upper limit (60)” can be combined to obtain “10 to 60.”

[Method for removing a semiconductor chip with a protective film attached]

The method for peeling off a semiconductor chip with a protective film attached according to the present invention comprises the following process (S1) and the following process (S2).

·Process (S1): A process of attaching a plurality of semiconductor chips with protective films to an adhesive layer (X1) with the protective film side as the bonding surface.

·Process (S2): A process of generating gas by sublimating at least a part of the protective film of some of the protective film-attached semiconductor chips among the plurality of protective film-attached semiconductor chips, and reducing the adhesive strength between some of the protective film-attached semiconductor chips and the adhesive layer (X1).

In the following description, the method for peeling off a semiconductor chip with a protective film attached according to the present invention is also simply referred to as “the method for peeling off according to the present invention.”

In addition, the method for peeling off a semiconductor chip with a protective film attached according to one embodiment of the present invention is also simply referred to as “the method for peeling off according to one embodiment of the present invention.”

Also, the process (S1) is also called the “preparation process”.

Additionally, process (S2) is also called “adhesion reduction process”.

Below, process (S1) and process (S2) are described.

[Process (S1): Preparation Process]

In process (S1), as shown in Fig. 1, a plurality of semiconductor chips (11) with protective films attached are attached to an adhesive layer (X1) with the protective film (13) side as the attachment surface.

A semiconductor chip (11) with a protective film attached is composed of a semiconductor chip (12) and a protective film (13). The protective film (13) is formed on the surface opposite to the circuit surface (12a) of the semiconductor chip (12), i.e., the back surface (12b) of the semiconductor chip (12).

The thickness of the semiconductor chip (12) is not particularly limited, but is usually 3 ㎛ to 500 ㎛.

The thickness of the protective film (13) is not particularly limited, but is preferably 0.05 ㎛ to 200 ㎛.

The size of the semiconductor chip (12) is not particularly limited, but is usually 5 ㎛ to 15 mm in length and 5 ㎛ to 15 mm in width.

Here, in (B-1) of Fig. 1, a plurality of semiconductor chips (11) with protective films are attached to the adhesive layer (X1) of the adhesive sheet (X) on which the adhesive layer (X1) is laminated on one side of the substrate (Y), but this is only an example, and as shown in (B-2) of Fig. 1, a plurality of semiconductor chips (11) with protective films may be attached to the adhesive layer (X1) that does not have the substrate (Y). The adhesive layer (X1) that does not have the substrate (Y) is used by attaching and fixing, for example, the surface opposite to the surface on which the plurality of semiconductor chips (11) with protective films are attached to a rigid substrate or the like.

In addition, the configuration of the adhesive sheet (X) is not limited to the configuration as in (B-1) of Fig. 1, and for example, an adhesive layer (X1) may be formed on both sides of the substrate (Y) (in this case, either adhesive layer (X1) may be an adhesive layer (X2) described later). In addition, a release agent may be provided on the adhesive surface of the adhesive layer (X1), and the release agent may be removed immediately before bonding a plurality of protective film-attached semiconductor chips (11) to the adhesive layer (X1) to expose the adhesive surface of the adhesive layer (X1).

＜Process (S1-1), Process (S1-2)＞

Here, in the preparation process of process (S1), a plurality of semiconductor chips (11) with protective films attached may be attached to the adhesive layer (X1) as described above, and the order of performing process (S1) is not limited, but from the viewpoint of efficiently carrying out the present invention, including the process of slicing the semiconductor wafer with protective films, in the peeling method of one embodiment of the present invention, process (S1) preferably includes the following processes (S1-1) to (S1-2) in this order.

·Process (S1-1): A process of attaching a semiconductor wafer with a protective film to an adhesive layer (X1) with the protective film side as the attachment surface.

·Process (S1-2): A process of dicing the semiconductor wafer with the protective film attached to obtain the plurality of semiconductor chips with the protective film attached.

(Process (S1-1))

In process (S1-1), as shown in Fig. 2, a semiconductor wafer (1) with a protective film attached is attached to an adhesive layer (X1) with the protective film (13) side as the attachment surface.

In addition, in Fig. 2, a semiconductor wafer (1) with a protective film attached is attached to an adhesive layer (X1) of an adhesive sheet (X), but this is only an example, and a semiconductor wafer (1) with a protective film attached may be attached to an adhesive layer (X1) that does not have a substrate (Y).

A semiconductor wafer (1) with a protective film attached is composed of a semiconductor wafer (2) and a protective film (13). The protective film (13) is formed on the surface opposite to the circuit surface (2a) of the semiconductor wafer (2), i.e., the back surface (2b) of the semiconductor wafer (2).

Examples of the semiconductor wafer (2) include a silicon wafer, a silicon carbide wafer, a compound semiconductor wafer, a glass wafer, and a sapphire wafer. In addition, the semiconductor wafer (2) may have a back surface that has been appropriately ground or the like to have a thickness of about 3 µm to 500 µm.

In addition, the shape of the semiconductor wafer (2) is not limited to a circle, and may be a square shape such as a square or rectangle, for example.

The thickness of the protective film (13) is preferably 0.05 ㎛ to 200 ㎛.

(Process (S1-2))

In process (S1-2), as shown in Fig. 2, a semiconductor wafer (1) with a protective film attached is diced to obtain a plurality of semiconductor chips (11) with a protective film attached.

The dicing method is not particularly limited, but known methods such as blade dicing and laser dicing can be employed. Dicing is performed, for example, by forming a cutting portion (20) so as to penetrate the semiconductor wafer (2) and the protective film (13).

In addition, after dicing, an expand process may be performed to widen the gap (width of the cut portion (20)) between the semiconductor chips (11) with the protective film attached.

(Method for manufacturing a semiconductor wafer with a protective film attached)

The method for manufacturing a semiconductor wafer with a protective film used in the process (S1-1) is not particularly limited, but from the viewpoint of making the film thickness of the protective film uniform and improving the covering property of the back surface of the semiconductor wafer by the protective film, the semiconductor wafer with a protective film is preferably obtained by bonding a protective film forming film to a semiconductor wafer and then curing the protective film forming film.

Curing of the protective film forming film can be performed by either thermal curing or curing by irradiation with energy rays, depending on the type of curable component included in the protective film forming film.

In addition, in this specification, “energy ray” means an electromagnetic wave or charged particle ray having energy quantum, and examples thereof include ultraviolet rays, electron rays, etc., and preferably ultraviolet rays.

Conditions for performing heat curing include a curing temperature of preferably 100°C to 170°C, and a curing time of preferably 1 hour to 3 hours.

In addition, the conditions for performing curing by irradiation with energy rays are appropriately determined depending on the type of energy rays used. For example, when using ultraviolet rays, the illuminance is preferably 170 mW/cm2 to 250 mW/cm2, and the light quantity is preferably 600 mJ/cm2 to 1,000 mJ/cm2.

The timing for performing curing of the protective film forming film may be before bonding the semiconductor wafer with the protective film forming film attached to the adhesive layer (X1), or may be after bonding the semiconductor wafer with the protective film forming film attached to the adhesive layer (X1).

Here, when curing the protective film-forming film is performed after the semiconductor wafer to which the protective film-forming film is adhered is adhered to the adhesive layer (X1), from the viewpoint of simplifying the process, it is preferable to adhere the protective film-forming film and the adhesive layer (X1) together to the back surface (2b) of the semiconductor wafer. Specifically, it is preferable to use a protective film-forming laminate in which a protective film-forming film is laminated on the adhesive layer (X1) of an adhesive sheet (X) having the adhesive layer (X1), and to adhere the protective film-forming film side of the protective film-forming laminate to the back surface of the semiconductor wafer, and then to cure the protective film-forming film.

[Process (S2): Adhesion reduction process]

In process (S2), among a plurality of semiconductor chips having a protective film attached, at least a portion of the semiconductor chips having a protective film attached is sublimated to generate gas, thereby reducing the adhesive strength between the semiconductor chips having a protective film attached and the adhesive layer (X1).

The present inventors have discovered a method for selectively reducing the adhesive strength of some of the semiconductor chips with a protective film attached among a plurality of semiconductor chips with a protective film with an adhesive layer (X1), wherein the protective film of the semiconductor chips with a protective film is actively utilized to sublimate a portion of the protective film to generate gas, thereby completing the present invention.

The method of generating gas by sublimating a portion of a protective film is not particularly limited, but for example, it is preferable to perform the method by irradiating laser light to at least a portion of the protective film of a semiconductor chip having a protective film attached thereto, using a protective film capable of absorbing laser light.

Fig. 3 shows an embodiment of a process (S2) using laser light. In addition, Fig. 4 is an enlarged view of the dotted line surrounding the Fig. 3, and is a diagram schematically showing a situation in which the adhesive strength of some of the semiconductor chips with protective films attached among a plurality of semiconductor chips with protective films is reduced with respect to the adhesive layer (X1).

In the process (S2) using laser light, it is preferable to irradiate the laser light from the side opposite to the bonding surface of the plurality of protective film-attached semiconductor chips of the adhesive layer (X1), and irradiate the protective film of the protective film-attached semiconductor chips. When using an adhesive sheet (X) having an adhesive layer (X1), for example, as shown in FIGS. 3 and 4, it is preferable to irradiate the protective film of some of the protective film-attached semiconductor chips (11a) with the laser light by causing the laser light L generated from the laser irradiation device (30) to be incident from the base material (Y) side of the adhesive sheet (X). As a result, a part of the protective film is ablated, a sublimation gas is generated, and the contact area between the protective film around the irradiated portion of the laser light L and the adhesive layer (X1) is reduced. In addition, by widening the irradiation area of the protective film of the laser light L, the protective film is extensively ablated, sublimation gas is generated, and the contact area between the protective film and the adhesive layer (X1) is further reduced. As a result, the adhesive strength of some of the protective film-attached semiconductor chips (11a) and the adhesive layer (X1) is reduced.

In addition, even if the sublimation gas leaks around some of the protective film-attached semiconductor chips (11a), the leaked sublimation gas is released from the cut portion (20). Therefore, the adhesive strength of the protective film-attached semiconductor chips that do not require peeling around some of the protective film-attached semiconductor chips (11a) can be prevented from deteriorating.

The laser irradiation device (30) is not particularly limited as long as it is a device capable of irradiating laser light capable of generating sublimation gas from a protective film, and for example, a laser irradiation device for performing laser marking on a protective film can be used.

Examples of such laser irradiation devices include the CSM2000 manufactured by EO Technics (solid-state green laser, wavelength: 532 nm), but are not necessarily limited to this device, and various devices capable of emitting laser light that can be absorbed by the protective film can be used.

The irradiation conditions of the laser light are not particularly limited as long as the protective film can absorb the laser light. However, from the viewpoint of more efficiently peeling off only some semiconductor chips with the protective film attached, for example, the frequency is preferably 10,000 Hz to 30,000 Hz. In addition, the beam diameter of the laser light is preferably 10 µm to 100 µm, more preferably 20 µm to 40 µm. The output of the laser light is preferably 0.1 W to 1.0 W. The scanning speed of the laser light is preferably 50 to 200 mm/sec.

In addition, laser light irradiation of the protective film of the semiconductor chip with the protective film to be peeled off is performed on at least a part of the bonding surface of the protective film with the adhesive layer (X1), so that the adhesive strength with the adhesive layer (X1) may be reduced. However, from the viewpoint of making it easier to further reduce the adhesive strength, it is preferable to perform the laser light irradiation on a certain area or more of the bonding surface of the protective film with the adhesive layer (X1). Specifically, the laser light irradiation area of the bonding surface of the protective film with the adhesive layer (X1) is preferably 50% or more, more preferably 60% or more, further preferably 70% or more, still more preferably 80% or more, still more preferably 90% or more, and particularly preferably 100% (i.e., the entire surface of the protective film) of the bonding surface of the protective film with the adhesive layer (X1). In addition, it is preferable that the laser light irradiation on the protective film be distributed over multiple areas rather than concentrated on a certain area. For example, by irradiating the laser light on the periphery and the center of the protective film, it is easy to effectively reduce the contact area between the protective film and the adhesive layer (X1), and therefore, it is easy to effectively reduce the adhesive strength between the protective film and the adhesive layer (X1).

In addition, as already described, laser light irradiation on the protective film is preferably performed from the side opposite to the bonding surface of the adhesive layer (X1) with the plurality of protective film-attached semiconductor chips toward the protective film. When using an adhesive sheet (X), it is preferably performed from the base material (Y) side toward the protective film. In addition, it is preferable to adjust the laser light so as to be irradiated to the bonding surface of the protective film with the adhesive layer (X1) or its vicinity. Here, the vicinity of the bonding surface of the protective film with the adhesive layer (X1) means a position at a distance of 10 μm or less from the bonding surface.

Next, the composition of the adhesive sheet (X) and the protective film forming film used in the peeling method of one embodiment of the present invention will be described below.

[Adhesive Sheet (X)]

The adhesive sheet (X) has a laminated structure of a substrate (Y) and an adhesive layer (X1).

In addition, the adhesive sheet (X) shown in (B-1) of FIG. 1 and FIGS. 2 to 5 is in the form of having an adhesive layer (X1) on one side of the substrate (Y), but is not limited thereto, and may be in the form of a double-sided adhesive sheet having an adhesive layer (X2) on the other side of the substrate (Y).

In addition, in the peeling method of one aspect of the present invention, it is preferable that the adhesive sheet (X) is a dicing tape. Hereinafter, each layer that may have the adhesive sheet (X) will be described.

＜Report (Y)＞

The substrate (Y) of the adhesive sheet (X) functions as a support that supports the adhesive layer (X1), and is composed of, for example, a resin film having laser light transparency and made mainly of a resin-based material.

Specific examples of the resin film 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. Additionally, modified films such as crosslinked films and ionomer films formed by crosslinking resins that form these films may be used.

The substrate (Y) may be made of one of these resin films alone, or may be made of a laminated film using two or more of these resin films in combination.

Here, from the viewpoint of versatility, and from the viewpoint of having relatively high strength and thus being easy to prevent warping, from the viewpoint of heat resistance, and from the viewpoint of improving laser light 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, and a polypropylene film. Specifically, the resin film is preferably a single-layer film having one or more layers selected from the group consisting of a polyethylene film, a polyester film, and a polypropylene film, or a laminated film in which two or more layers are laminated.

In addition, from the viewpoint of making it easy to secure high light transmittance for light of a desired wavelength, it is preferable to increase the smoothness on the first surface of the substrate (Y) (the surface opposite to the surface on which the adhesive layer (X1) is formed). Specifically, it is preferable that the arithmetic mean roughness Ra on the first surface of the substrate (Y) is 0.01 µm to 0.8 µm. In addition, the arithmetic mean roughness Ra is a value measured in accordance with JIS B 0601: 1994.

In addition, the substrate (Y) may contain a coloring agent, but when using laser light in the adhesive strength reduction step of the step (S2), from the viewpoint of making the substrate with better laser light transmittance, it is preferable that the content of the coloring agent that absorbs the laser light is small. Specifically, the content of the coloring agent that absorbs the laser light is preferably less than 0.1 mass%, more preferably less than 0.01 mass%, even more preferably less than 0.001 mass%, and even more preferably, no coloring agent is contained, based on the total amount of the substrate (Y).

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

＜Adhesive layer (X1)＞

The adhesive layer (X1) may contain an adhesive resin, and may contain adhesive additives such as a crosslinking agent, a tackifier, a polymerizable compound, or a polymerization initiator, as needed.

The adhesive layer (X1) can be formed from an adhesive composition containing an adhesive resin.

Below, each component included in the adhesive composition, which is a forming material of the adhesive layer (X1), is described.

(adhesive resin)

The adhesive resin is preferably a polymer that has adhesiveness by itself and has a mass average molecular weight (Mw) of 10,000 or more.

The mass average molecular weight (Mw) of the adhesive resin is, from the viewpoint of improving adhesive strength, more preferably 10,000 to 2 million, further preferably 20,000 to 1.5 million, and still more preferably 30,000 to 1 million.

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

These adhesive resins may be used alone or in combination of two or more types.

In addition, when these adhesive resins are copolymers having two or more types of constituent 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.

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

Examples of the polymerizable functional group include (meth)acryloyl group and vinyl group.

Also, energy rays include ultraviolet rays and electron rays, but ultraviolet rays are preferred.

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

In addition, in the following description of this specification, “content of each component relative to the total amount of effective ingredients of the adhesive composition” has the same meaning as “content of each component in the adhesive layer formed from the adhesive composition.”

Here, from the viewpoint of exhibiting excellent adhesiveness and suppressing the phenomenon of cutting water intruding between the adhesive layer (X1) and the protective film during dicing, it is preferable that the adhesive resin include an acrylic resin.

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

(Acrylic resin)

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, polymers containing a structural unit derived from a (meth)acrylate having a cyclic structure, etc.

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

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 preferable.

The number of carbon atoms in the alkyl group of the monomer (a1') is preferably 1 to 24, more preferably 1 to 12, even more 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 from the viewpoint of suppressing the phenomenon of cutting water penetrating between the adhesive layer (X1) and the protective film during dicing.

Additionally, the alkyl group of the monomer (a1') may be a straight-chain alkyl group or a branched-chain alkyl group.

Examples of monomers (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.

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

As monomers (a1'), butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are preferred.

The content of the constituent unit (a1) is preferably 50 to 99.9 mass%, more preferably 60 to 99.0 mass%, further preferably 70 to 97.0 mass%, and still more preferably 80 to 95.0 mass%, relative to the total constituent units (100 mass%) of the acrylic copolymer (A1).

Functional groups possessed by the monomer (a2') include, for example, a hydroxyl group, a carboxyl group, an amino group, and an epoxy group.

In short, examples of monomers (a2') include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, and epoxy group-containing monomers.

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

Among these, as monomers (a2'), hydroxyl group-containing monomers and carboxyl group-containing monomers are preferred.

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; unsaturated alcohols such as vinyl alcohol and allyl alcohol; and the like.

Examples of carboxyl group-containing monomers include ethylenically unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids and their anhydrides such as fumaric acid, itaconic acid, maleic acid, and citraconic acid; 2-(acryloyloxy)ethylsuccinate, and 2-carboxyethyl(meth)acrylate.

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

The acrylic copolymer (A1) may additionally have a structural unit (a3) derived from a monomer (a3') other than monomers (a1') and (a2').

In addition, in the acrylic copolymer (A1), the content of the constituent units (a1) and (a2) is preferably 70 to 100 mass%, more preferably 80 to 100 mass%, even more preferably 90 to 100 mass%, and even more preferably 95 to 100 mass%, relative to the total constituent units (100 mass%) of the acrylic copolymer (A1).

Monomers (a3') include, for example, 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, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and imide (meth)acrylate; Examples thereof include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, (meth)acrylamide, (meth)acrylonitrile, (meth)acryloylmorpholine, and N-vinylpyrrolidone.

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

Examples of the polymerizable functional group include (meth)acryloyl group and vinyl group.

Also, energy rays include ultraviolet rays and electron rays, but ultraviolet rays are preferred.

In addition, the polymerizable functional group can be introduced by reacting an acrylic copolymer having the above-described structural units (a1) and (a2) with a compound having a polymerizable functional group and a substituent capable of bonding to the functional group of the structural unit (a2) of the acrylic copolymer.

Examples of the compounds include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

(crosslinking agent)

It is preferable that the adhesive composition additionally contain a crosslinking agent.

The crosslinking agent reacts with an adhesive resin having a functional group, such as the acrylic copolymer (A1) described above, and crosslinks the adhesive resins using the functional group as a crosslinking starting point.

Examples of crosslinking agents include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, and metal chelate crosslinking agents.

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

Among these crosslinking agents, isocyanate crosslinking agents are preferable from the viewpoint of increasing cohesion and improving adhesiveness, and from the viewpoint of ease of acquisition.

The content of the crosslinking agent is appropriately adjusted depending on the number of functional groups possessed by 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.

(adhesive)

The adhesive composition may additionally contain a tackifier from the viewpoint of further improving adhesive strength.

In this specification, “tackifier” refers to an oligomer having a mass average molecular weight (Mw) of less than 10,000, which is a component that auxiliary improves the adhesive strength of the above-described adhesive resin, and is distinct from the above-described adhesive resin.

The mass average molecular weight (Mw) of the adhesive agent is preferably 400 to less than 10,000, more preferably 500 to 8,000, and even more preferably 800 to 5,000.

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

The softening point of the adhesive agent is preferably 60 to 170°C, more preferably 65 to 160°C, and even more preferably 70 to 150°C.

In addition, in this specification, the “softening point” of the adhesive agent means a value measured in accordance with JIS K 2531.

The adhesive agent may be used alone, or two or more types having different softening points, structures, etc. may be used in combination.

In addition, when two or more types of tackifiers are used, it is preferable that the weighted average of the softening points of the tackifiers falls within the above range.

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

(photopolymerization initiator)

When the adhesive composition includes an energy-ray-curable adhesive resin as the adhesive resin, it is preferable to additionally contain a photopolymerization initiator.

By containing a photopolymerization initiator, the curing reaction can be sufficiently promoted even by irradiation with relatively low-energy energy rays.

Examples of photopolymerization initiators include 1-hydroxy-cyclohexyl-phenyl-ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzyl phenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, and 8-chloranthraquinone.

These photopolymerization initiators may be used alone or in combination of two or more types.

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, per 100 parts by mass of the energy ray-curable adhesive resin.

(additive for adhesive)

The adhesive composition, which is a forming material of the adhesive layer (X1), may contain, in addition to the additives described above, an adhesive additive used in general adhesives.

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

In addition, each of these adhesive additives may be used alone, or two or more may be used in combination.

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, per 100 parts by mass of the adhesive resin.

Here, the adhesive composition may contain at least one of a pigment and a dye, but when using laser light in the adhesive strength reduction step of step (S2), from the viewpoint of laser light transmittance, it is preferable that the content of the pigment and dye that absorb the laser light is small.

Specifically, the content of pigments and dyes that absorb laser light is preferably less than 0.1 mass%, more preferably less than 0.01 mass%, even more preferably less than 0.001 mass%, and even more preferably, no pigments or dyes are contained, relative to the total amount of the adhesive composition.

In addition, when using laser light in the adhesive strength reduction process of process (S2), an adhesive composition capable of preventing scattering of laser light is preferable.

＜Adhesive layer (X2)＞

When the adhesive sheet (X) is a double-sided adhesive sheet, the adhesive layer (X2) of the double-sided adhesive sheet may contain an adhesive resin, and may contain an adhesive additive such as a crosslinking agent, a tackifier, a polymerizable compound, or a polymerization initiator, as necessary.

The preferred embodiments of the composition and shape of the adhesive layer (X2) are the same as those of the adhesive layer (X1). However, the compositions of the adhesive layer (X1) and the adhesive layer (X2) may be the same or different. In addition, the shapes of the adhesive layer (X1) and the adhesive layer (X2) may be the same or different.

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

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

Park Ri-jae

A release agent may be additionally formed on one or both adhesive surfaces of the adhesive layer (X1) of the adhesive sheet (X) and the adhesive layer (X2) that the adhesive sheet (X) may have.

Examples of release materials include release sheets with double-sided release treatment, release sheets with single-sided release treatment, and those in which a release agent is applied to a substrate for release materials.

Examples of substrates for the release agent 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.

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

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

＜Method for manufacturing adhesive sheet (X)＞

There is no particular limitation on the method for manufacturing the adhesive sheet (X), and it can be manufactured by a known method. For example, an organic solvent is added to a raw material composition containing each of the above-described components (hereinafter also referred to as a “pressure-sensitive adhesive layer-forming composition”) to form a solution of the raw material composition, and the solution is applied onto a substrate (Y) by a known application method to form a coating film, and then dried to form an adhesive layer (X1) on the substrate (Y).

In addition, the solution is applied to the above-described release agent by a known application method to form a coating film, and then dried to form an adhesive layer (X1) on the release agent, and then the base material (Y) and the adhesive layer (X1) are bonded together to manufacture an adhesive sheet (X) having a laminated structure of release agent/adhesive layer (X1)/base material (Y).

Organic solvents used include toluene, ethyl acetate, and methyl ethyl ketone.

The solid content concentration of the solution of the adhesive layer forming composition when an organic solvent is mixed is preferably 10 to 80 mass%, more preferably 25 to 70 mass%, and even more preferably 45 to 65 mass%.

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

[Protective film formation]

As for the protective film forming film, there is no particular limitation, but it is preferable to include a polymer component (B) and a curable component (C), and may additionally contain a colorant (D), a coupling agent (E), an inorganic filler (F), and a general-purpose additive (G).

Hereinafter, the components (B) to (G) included in the protective film forming film will be described.

＜Polymer component (B)＞

"Polymer component" means a compound having a mass average molecular weight (Mw) of 20,000 or more and at least one type of repeating unit. By including a polymerizable component (B) in the protective film-forming film, flexibility and film-forming properties can be mainly provided to the protective film-forming film, and sheet-like properties can be maintained well.

The mass average molecular weight (Mw) of the polymer component (B) is preferably 20,000 to 3 million, more preferably 50,000 to 2 million, and even more preferably 100,000 to 1.5 million.

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 still more preferably 12 to 25 mass%, relative to the total amount (100 mass%) of the protective film-forming film.

As the polymer component (B), an acrylic polymer (B1) is preferable, and other than an acrylic polymer (B1), a non-acrylic polymer (B2) such as polyester, phenoxy resin, polycarbonate, polyether, polyurethane, polysiloxane, or rubber polymer may be used.

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

(Acrylic polymer (B1))

The mass average molecular weight (Mw) of the acrylic polymer (B1) is preferably 20,000 to 3 million, more preferably 100,000 to 1.5 million, further preferably 150,000 to 1.2 million, and still more preferably 250,000 to 1 million, from the viewpoint of imparting flexibility and film-forming properties to the protective film-forming film.

The glass transition temperature (Tg) of the acrylic polymer (B1) is preferably -60 to 50°C, more preferably -50 to 40°C, even more preferably -40 to 30°C, and even more preferably -35 to 20°C, from the viewpoint of the adhesiveness of the protective film formed from the protective film forming film to the adherend and the viewpoint of improving the reliability of the chip to which the protective film is attached.

As the acrylic polymer (B1), a polymer containing an alkyl (meth)acrylate as a main component can be exemplified. 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 preferable, and an acrylic copolymer containing a structural unit (b2) derived from a functional group-containing monomer together with the structural unit (b1) is more preferable.

Ingredient (B1) can be used alone or in combination of two or more types.

In addition, when the component (B1) is a copolymer, the form of the copolymer may be any of a block copolymer, a random copolymer, an alternating copolymer, and a graft copolymer.

(Composition unit (b1))

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

Examples of alkyl (meth)acrylates 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, stearyl (meth)acrylate, etc.

Additionally, these alkyl (meth)acrylates may be used alone or in combination of two or more types.

Among these, an alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms is preferable, an alkyl (meth)acrylate having an alkyl group having 4 to 6 carbon atoms is more preferable, and butyl (meth)acrylate is even more preferable.

The content ratio of the structural unit derived from an alkyl (meth)acrylate 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%, with respect to the total structural units (100 mass%) of the acrylic polymer (B1).

Also, from the viewpoint of improving the reliability of the chip to which the protective film is attached, an alkyl (meth)acrylate having an alkyl group having 1 to 3 carbon atoms is preferable, and methyl (meth)acrylate is more preferable.

From the above viewpoint, the content ratio of the structural unit derived from an alkyl (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%, with respect to the total structural units (100 mass%) of the acrylic polymer (B1).

The content ratio of the constituent unit (b1) is preferably 50 mass% or more, more preferably 50 to 99 mass%, further preferably 55 to 90 mass%, and further preferably 60 to 80 mass%, relative to the total constituent units (100 mass%) of the acrylic polymer (B1).

(composition unit (b2))

Examples of the functional group-containing monomer constituting the structural unit (b2) include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an epoxy group-containing monomer, an amino group-containing monomer, a cyano group-containing monomer, a keto group-containing monomer, a monomer having a nitrogen atom-containing ring, an alkoxysilyl group-containing monomer, and the like.

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

Among these, a hydroxyl group-containing monomer is preferable.

As a hydroxyl group-containing monomer, those exemplified in the description of the hydroxyl group-containing monomer in the adhesive layer (X1) can be cited, but 2-hydroxyethyl (meth)acrylate is preferable.

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

By using a carboxyl group-containing monomer, a carboxyl group is introduced into the acrylic polymer (B1), and when the protective film-forming film contains an energy ray-curable component as the curable component (C), the compatibility of the component (C) and the component (B) is improved.

In addition, when using an epoxy-based thermosetting component as the curable component (C) described later, it is preferable that the content of the structural unit derived from a carboxyl group-containing monomer be small, because the carboxyl group and the epoxy group in the epoxy-based thermosetting component react.

When an epoxy-based thermosetting component is used as the curable component (C), the content of the structural unit derived from a 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 the total structural units (100 mass%) of the (A1) acrylic polymer.

Examples of epoxy-containing monomers include epoxy group-containing (meth)acrylic acid esters and non-acrylic epoxy group-containing monomers.

Examples of epoxy group-containing (meth)acrylic acid esters include glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and 3-epoxycyclo-2-hydroxypropyl (meth)acrylate.

In addition, examples of non-acrylic epoxy group-containing monomers include glycidyl crotonate and allyl glycidyl ether.

Among these, epoxy group-containing (meth)acrylic acid ester is preferable, and glycidyl (meth)acrylate is more preferable.

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

From the viewpoint of facilitating the improvement of the sublimation property of the protective film, the content ratio of the structural unit derived from the epoxy group-containing monomer is preferably 1 to 30 mass%, more preferably 5 to 27 mass%, and even more preferably 10 to 24 mass%, relative to the total structural units (100 mass%) of the acrylic polymer (B1).

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

(Other monomer-derived structural units)

In addition, the acrylic polymer (B1) may have a structural unit derived from a monomer other than the structural units (b1) and (b2), as long as the effects of the present invention are not impaired.

Other monomers include, for example, vinyl acetate, styrene, ethylene, and α-olefins.

(Non-acrylic resin (B2))

The protective film forming film may, if necessary, contain a non-acrylic resin (B2) as a resin component other than the acrylic polymer (B1) described above.

Non-acrylic resins (B2) include, for example, polyester, phenoxy resin, polycarbonate, polyether, polyurethane, polysiloxane, and rubber polymers.

These resins may be used alone or in combination of two or more types.

The mass 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.

The non-acrylic resin (B2) can be used alone, but when used in combination with the acrylic polymer (B1) described above, when an adhesive sheet and a protective film forming film are laminated, interlayer peeling can be easily performed, and the occurrence of voids, etc. can be suppressed.

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

In addition, in the case where the acrylic polymer (B1) includes a constituent unit derived from an epoxy group-containing monomer in the constituent units constituting the acrylic polymer (B1), or a phenoxy resin having an epoxy group has thermosetting properties, these are not curable components (C), but are included in the concept of polymer components (B).

＜Curing component (C)＞

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

As the curable component (C), it is preferable to use a thermosetting component (C1) and/or an energy ray curable component (C2), and from the viewpoint of sufficiently progressing the curing reaction and from the viewpoint of reducing costs, it is more preferable to use at least the thermosetting component (C1).

As the thermosetting component (C1), it is preferable to contain at least a compound having a functional group that reacts by heating.

In addition, the energy ray curable component (C2) contains a compound (C21) having a functional group that reacts upon energy ray irradiation, and polymerizes and cures upon irradiation with energy ray such as ultraviolet rays or electron rays.

Curing is achieved by the reaction between the functional groups of these curable components, forming a three-dimensional network structure.

The mass 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 a protective film by using it in combination with the component (B) and improving handleability.

(Thermosetting component (C1))

As the thermosetting component (C1), an epoxy-based thermosetting component is preferable.

It is preferable to use an epoxy thermosetting component that combines a thermosetting agent (C12) with a compound (C11) having an epoxy group.

Examples of compounds (C11) having an epoxy group (hereinafter also referred to as “epoxy compound (C11)”) include epoxy compounds having two or more functional groups in their molecules, such as multifunctional epoxy resins, bisphenol A diglycidyl ether and hydrogenated products thereof, orthocresol novolac epoxy resins, dicyclopentadiene-type epoxy resins, biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and phenylene skeleton-type epoxy resins.

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

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 still more preferably 20 to 120 parts by mass, relative to 100 parts by mass of component (B).

(thermosetting agent (C12))

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

As a thermosetting agent, a compound having two or more functional groups capable of reacting with an epoxy group per molecule is preferable.

Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an acid anhydride group (acid anhydride structure). Among these, a phenolic hydroxyl group, an amino group, or an acid anhydride group is preferable, a phenolic hydroxyl group or an amino group is more preferable, and an amino group is even more preferable.

Examples of phenolic thermosetting agents having a phenol group include multifunctional phenol resins, biphenols, novolac-type phenol resins, dicyclopentadiene-type phenol resins, xyloc-type phenol resins, and aralkylphenol resins.

Examples of amine-based heat curing agents having an amino group include dicyandiamide (DICY).

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

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

(Curing Accelerator (C13))

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

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 tetraphenyl boron salts such as tetraphenylphosphoniumtetraphenylborate and triphenylphosphinetetraphenylborate.

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

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), from the viewpoint of improving the adhesiveness of the protective film formed from the protective film forming film and improving the reliability of the chip to which the protective film is attached.

(Energy ray curable component (C2))

As the energy ray curable component (C2), a compound (C21) having a functional group that reacts by energy ray irradiation may be used alone, but it is preferable to use a photopolymerization initiator (C22) in combination with the compound (C21).

(Compound (C21) having a functional group that reacts with energy ray irradiation)

Examples of compounds (C21) having a functional group that reacts by energy ray irradiation (hereinafter also referred to as “energy ray reactive compounds (C21)”) include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, oligoester acrylate, urethane acrylate oligomers, epoxy acrylates, polyether acrylates, itaconic acid oligomers, and the like.

These energy-reactive compounds (C21) may be used alone or in combination of two or more.

In addition, the mass average molecular weight (Mw) of the energy ray reactive compound (C21) is preferably 100 to 30,000, more preferably 300 to 10,000.

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 component (B).

(Photopolymerization initiator (C22))

By using the energy ray reactive compound (C21) described above together with a photopolymerization initiator (C22), the polymerization curing time can be shortened, and curing of the protective film forming film can be promoted even with a small amount of light irradiation.

As photopolymerization initiators (C22), those described above can be mentioned.

The content of the photopolymerization initiator (C22) is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the energy ray reactive compound (C21), from the viewpoint of sufficiently promoting the curing reaction and suppressing the generation of residue.

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

In addition, the content of component (C) is the total content of the thermosetting component (C1) including the above-described epoxy compound (C11), thermosetting agent (C12), and curing accelerator (C13), and the energy ray-curable component (C2) including the energy ray-reactive compound (C21) and the photopolymerization initiator (C22).

＜Colorant (D)＞

It is preferable that the protective film forming film additionally contains a coloring agent (D).

Since the protective film forming film contains a colorant (D), when laser light is used in the adhesion reduction process of process (S2), the laser light absorption rate of the protective film can be improved by selecting the type and content of the colorant (D), thereby improving the sublimation property of the protective film. In short, since the protective film formed by the protective film forming film contains a colorant (D) capable of absorbing laser light, the sublimation property of the protective film can be improved.

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

The pigment may be either an organic or an inorganic pigment.

Dyes include, for example, basic dyes, acid dyes, disperse dyes, and direct dyes.

Examples of black pigments include carbon black, copper oxide, iron trioxide, manganese dioxide, aniline black, and activated carbon.

Examples of yellow pigments include lead sulfide, zinc sulfur, cadmium yellow, yellow iron oxide, mineral first yellow, nickel titanium yellow, Naples yellow, naphthol yellow S, Hansa yellow, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartrazine lake.

Examples of the orange pigments include red lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, and indanthrene brilliant orange GKM.

Examples of red pigments include Bengala, cadmium red, mercury sulfide, cadmium, permanent red 4R, lithol red, pyrrolo red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake, and brilliant carmine 3B.

Examples of purple pigments include manganese violet, first violet B, and methyl violet lake.

Examples of blue pigments include prussian blue, cobalt blue, alkaline blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, first sky blue, and indanthrene blue BC.

Examples of green pigments include chrome green, chromium oxide, pigment green B, malachite green lake, and final yellow green G.

Dyes include, for example, nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

Here, in the adhesion reduction process of process (S2), it is preferable to use a black pigment or black dye to facilitate improving laser light absorption over a wide wavelength range. Among black pigments, carbon black is more preferable to improve the reliability of semiconductor chips. From the same perspective, among black dyes, nigrosine is more preferable.

In addition, these colorants (D) may be used alone or in combination of two or more.

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 still more preferably 1.2 to 5 mass%, relative to the total amount (100 mass%) of the protective film-forming film.

Coupling agent (E)

It is preferable that the protective film forming film additionally contains a coupling agent (E).

By including a coupling agent (E), the polymer component in the protective film forming film can be bonded to the surface of the semiconductor chip or the surface of the filler, which is the adherend, thereby improving adhesiveness and cohesiveness. In addition, the water resistance of the protective film formed from the protective film forming film can be improved without impairing the heat resistance.

As the coupling agent (E), a compound that reacts with a functional group of component (B) or component (C) is preferable, and a silane coupling agent is more preferable.

Silane coupling agents include, for example, 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)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, Examples include vinyltriacetoxysilane and imidazolesilane.

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

As a coupling agent (E), an oligomer type coupling agent is preferable.

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

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 still more preferably 0.15 to 2 mass%, relative to the total amount (100 mass%) of the protective film-forming film.

Weapon Refill (F)

It is preferable that the protective film forming film additionally contains an inorganic filler (F).

By including an inorganic filler (F), it becomes possible to adjust the coefficient of thermal expansion of the protective film after curing of the protective film forming film to an appropriate range, thereby optimizing the coefficient of thermal expansion of the protective film after curing for the semiconductor chip, thereby improving the reliability of the semiconductor device. In addition, it also becomes possible to reduce the moisture absorption rate of the protective film after curing.

Examples of inorganic fillers (F) include powders of silica, alumina, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride, spheroidized beads of these, single crystal fibers, and glass fibers.

These weapon fillers (F) may be used alone or in combination of two or more types.

Among these, silica or alumina is preferred.

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 gloss value of the protective film formed from the protective film forming film.

In addition, in the present invention, the average particle diameter of the inorganic filler (F) means a value measured using a laser diffraction scattering particle size distribution measuring device.

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 still more preferably 45 to 60 mass%, relative to the total amount (100 mass%) of the protective film forming film.

＜General Purpose Additive (G)＞

In addition to the above, various additives may be mixed into the protective film forming film as needed.

Various additives include crosslinking agents, leveling agents, plasticizers, antistatic agents, antioxidants, ion scavengers, gettering agents, and chain transfer agents.

＜Method for manufacturing a protective film formation film＞

There is no particular limitation on the method for producing a protective film-forming film, and it can be produced by a known method. For example, an organic solvent is added to a raw material composition containing each of the above-described components (hereinafter also referred to as a "protective film-forming composition") to form a solution of the protective film-forming composition, and the solution is applied onto the above-described peeling sheet by a known application method to form a coating film, followed by drying, and a protective film-forming film can be formed on the peeling sheet.

Organic solvents used include toluene, ethyl acetate, and methyl ethyl ketone.

The solid content concentration of the solution of the protective film-forming composition when an organic solvent is mixed is preferably 10 to 80 mass%, more preferably 20 to 70 mass%, and even more preferably 30 to 65 mass%.

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

The protective film forming film may be a single layer or a multilayer structure of two or more types.

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. Even when the protective film forming film has a multilayer configuration, it is preferable that the total thickness (sum of the thicknesses of each layer) be within the range.

<Method for manufacturing a laminate for forming a protective film>

There is no particular limitation on the method for manufacturing a laminate for forming a protective film including a laminated structure with a protective film forming film and an adhesive sheet (X), and it can be manufactured by a known method.

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, by bonding the adhesive layer (X1) of the adhesive sheet (X) and the protective film forming film formed on the release sheet, a protective film forming laminate having a laminated structure of release sheet/protective film forming film/adhesive layer (X1), or release sheet/protective film forming film/adhesive layer (X1)/substrate (Y) can be produced.

[How to pick up a semiconductor chip with a desired protective film attached]

The method for picking up a semiconductor chip with a protective film attached, the adhesive strength of which has been reduced with respect to the adhesive layer (X1) by the process (S2), is not particularly limited, but examples thereof include a method of pushing it up from the lower side with a pin or the like through an adhesive sheet (X) and picking it up with a vacuum collet or the like.

Here, in the manufacturing method of one aspect of the present invention, it is preferable to pick up the semiconductor chip with the protective film attached, the adhesive strength of which has been reduced with respect to the adhesive layer (X1) by the process (S2), by the method shown below.

That is, it is preferable to perform the following process (SP1) before or after the process (S2), and also to perform the following process (SP2) after the following process (SP1) and also after the process (S2).

·Process (SP1): A process of laminating the adhesive layer (Z1) of the transfer sheet (Z) having the adhesive layer (Z1) with the surface opposite to the protective film side of the plurality of protective film-attached semiconductor chips as the bonding surface, and laminating the adhesive layer (X1) and the transfer sheet (Z) with the plurality of protective film-attached semiconductor chips interposed therebetween.

·Process (SP2): A process of separating the transfer sheet (Z) and the adhesive layer (X1), peeling only the semiconductor chips with a protective film attached thereto from the adhesive layer (X1), and transferring the semiconductor chips with a protective film attached thereto onto the transfer sheet (Z).

In the following explanation, this method is also called the "translation method."

In the process (SP1), as shown in Fig. 5, the adhesive layer (Z1) of the transfer sheet (Z) having the adhesive layer (Z1) is attached to a plurality of protective film-attached semiconductor chips (11) (including some protective film-attached semiconductor chips (11a) requiring peeling) with the surface opposite to the protective film side as the attachment surface, and the adhesive layer (X1) and the transfer sheet (Z) are laminated with the plurality of protective film-attached semiconductor chips (11) interposed therebetween.

＜Warrior Sheet (Z)＞

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

The substrate (Y') can be the same as the substrate (Y) of the adhesive sheet (X), and its thickness is also the same as that of the substrate (Y).

In addition, the adhesive layer (Z1) may be the same as the adhesive layer (X1) of the adhesive sheet (X).

Process (SP1) may be performed before process (S2) or after process (S2). Regardless of the timing, it does not affect the adhesive strength reduction process in process (S2).

Then, the process (S2) is performed, and the adhesive strength of some of the protective film-attached semiconductor chips (11a) with the adhesive layer (X1) is reduced, and the transfer sheet (Z) and the adhesive sheet (X) are separated, as shown in Fig. 5. As a result, only some of the protective film-attached semiconductor chips (11a) can be peeled off from the adhesive sheet (X), and some of the protective film-attached semiconductor chips (11a) can be transferred to the transfer sheet (Z).

Here, the transfer method is not limited to the above method. For example, after performing the process (S2), and while the adhesive strength of some of the protective film-attached semiconductor chips (11a) with the adhesive layer (X1) is reduced, the porous table may be placed in contact with the surface opposite to the protective film side of the plurality of protective film-attached semiconductor chips (11), and some of the protective film-attached semiconductor chips (11a) may be adsorbed and transferred to the porous table. The adsorption by the porous table may be selectively performed only on some of the protective film-attached semiconductor chips (11a) with reduced adhesive strength, or may be performed on the entire surface of the adhesive layer (X1). When the adsorption by the porous table is performed on the entire surface of the adhesive layer (X1), only some of the protective film-attached semiconductor chips (11a) with reduced adhesive strength can be adsorbed and transferred to the porous table by separating the adhesive layer (X1) adsorbed to the porous table from the porous table. In addition, the average pore diameter of the porous table used at this time is preferably 60 μm or less, more preferably 55 μm or less, from the viewpoint of adsorbing and transferring only a portion of the protective film-attached semiconductor chip (11a) whose adhesive strength with the adhesive layer (X1) is reduced by weakly sucking the entire surface. In addition, the porosity is preferably 30% to 60%, more preferably 45% to 60%.

Also, for example, by performing process (S2), the adhesive strength of some of the protective film-attached semiconductor chips (11a) with the adhesive layer (X1) is reduced, and the electrostatic chuck is placed in contact with the surface opposite to the protective film side of the plurality of protective film-attached semiconductor chips (11), and some of the protective film-attached semiconductor chips (11a) are gripped and transferred by the electrostatic chuck. The gripping by the electrostatic chuck may be selectively performed only on some of the protective film-attached semiconductor chips (11a) with reduced adhesive strength, or may be performed on the entire surface of the adhesive layer (X1). When the gripping by the electrostatic chuck is performed on the entire surface of the adhesive layer (X1), only some of the protective film-attached semiconductor chips (11a) with reduced adhesive strength can be gripped and transferred by the electrostatic chuck by separating the adhesive layer (X1) gripped by the electrostatic chuck from the electrostatic chuck. In addition, at this time, from the viewpoint of gripping and transferring only a portion of the protective film-attached semiconductor chip (11a) whose adhesive strength with the adhesive layer (X1) is reduced by gripping the entire surface with a weak force, an adhesive sheet in which a substrate and an adhesive layer are laminated may be attached to the electrostatic chuck as a cushioning material to weaken the gripping force.

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

A method for manufacturing a semiconductor chip with a protective film attached, which is one embodiment of the present invention, includes a step of performing the peeling method of the present invention or the peeling method of one embodiment of the present invention, including steps (S1) and (S2).

In particular, the method for manufacturing a semiconductor chip with a protective film of the present invention is preferable because it is possible to efficiently manufacture a semiconductor chip with a protective film from a semiconductor wafer with a protective film by including a step (S1) of performing a peeling method of one aspect of the present invention including steps (S1-1) to (S1-2) in this order.

In addition, since process (S1) includes processes (S1-1) to (S1-2) in this order and also includes a process for performing the method for manufacturing a semiconductor wafer with a protective film described above, it is preferable that a semiconductor chip with a protective film be manufactured efficiently from a semiconductor wafer.

[Method for manufacturing a semiconductor device including a semiconductor chip with a protective film attached]

In this specification, “semiconductor device” refers to a device in general that can function by utilizing semiconductor characteristics, such as those used in processors, memories, and sensors.

A method for manufacturing a semiconductor device including a semiconductor chip with a protective film, which is one embodiment of the present invention, includes a step of performing the stripping method of the present invention, including steps (S1) and (S2), or a step of performing the stripping method of one embodiment of the present invention. Accordingly, among a plurality of semiconductor chips with protective films, only some of the semiconductor chips with protective films can be provided to a semiconductor device processing step. Specifically, among a plurality of semiconductor chips with protective films, only some of the semiconductor chips with protective films can be provided to a step of mounting them into a semiconductor device. For example, it becomes possible to selectively provide only good semiconductor chips with protective films to a step of mounting them into a semiconductor device, thereby contributing to an improvement in the yield of the semiconductor device.

Example

The present invention will be specifically described by the following examples, but the present invention is not limited to the following examples.

On the adhesive layer (X1) of the adhesive sheet (X), 10 semiconductor chips with protective films attached (chip size: 1 mm × 1 mm, chip thickness: 200 ㎛, protective film thickness: 25 ㎛) were arranged in series with a chip spacing of 30 ㎛, and attached with the protective film side as the attachment surface, thereby preparing an adhesive sheet (X) in which a plurality of semiconductor chips with protective films attached were attached.

The adhesive sheet (X) uses the following dicing tape, which is a configuration in which an adhesive layer (X1) is laminated on a substrate (Y). In addition, the arithmetic mean roughness Ra of the surface opposite to the surface on which the adhesive layer (X1) of the substrate (Y) is formed is 0.1 ㎛.

·Dicing tape (Lintec, Adwill D-456H)

The protective film forming film and curing conditions used to form the protective film of the protective film-attached semiconductor chip were as follows.

·Protective film formation film: ADWILL LC2850 (25)

·Curing conditions: 130℃, 2 hours

In addition, the protective film forming film contains carbon black, and the protective film formed by curing the protective film forming film can absorb laser light, which will be described later.

Among the adhesive sheets (X) on which multiple semiconductor chips with protective films are attached, a laser beam was irradiated from the substrate (Y) side toward one semiconductor chip with a protective film. The irradiation conditions were as follows.

(Laser light irradiation conditions)

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

·Frequency: 20,000 Hz to 25,000 Hz

Scanning speed: 100 mm/s

·Output: 0.12 W ~ 0.82 W

·Beam diameter: 35 ㎛

(Experimental results)

Among the adhesive sheets (X) on which a plurality of semiconductor chips with protective films are adhered, when a laser beam is irradiated from the substrate (Y) side toward one semiconductor chip with protective films, it can be visually confirmed from the substrate (Y) side that air is gathered and formed at the interface between the semiconductor chip with protective films and the adhesive layer (X1), and it can be seen that the adhesive strength with the adhesive layer (X1) can be significantly reduced only for the semiconductor chip with protective films. On the other hand, the remaining semiconductor chips with protective films do not have air gathered and formed at the interface with the adhesive layer (X1), and thus they are maintained in a state of being firmly adhered to the adhesive layer (X1) without the adhesive strength with the adhesive layer (X1) being reduced.

1: Semiconductor wafer with protective film attached
2: Semiconductor wafer
11: Semiconductor chip with protective film attached
12: Semiconductor chips
13: Shield
20: Incision
30: Laser irradiation device
X: Adhesive sheet
X 1: Adhesive layer
Y: Description
Z: Transfer Sheet
Z1: Adhesive layer
Y': Description

Claims (9)

A method for peeling off a semiconductor chip with a protective film attached, comprising the following process (S1) and the following process (S2).
·Process (S1): Includes the following processes (S1-1) to (S1-2) in this order.
·Process (S1-1): A process of attaching a semiconductor wafer with a protective film to an adhesive layer (X1) with the protective film side as the attachment surface.
·Process (S1-2): Process of dicing the semiconductor wafer with the protective film attached and obtaining a plurality of semiconductor chips with the protective film attached.
·Process (S2): A process of generating gas by sublimating at least a part of the protective film of some of the protective film-attached semiconductor chips among the plurality of protective film-attached semiconductor chips, and reducing the adhesive strength between some of the protective film-attached semiconductor chips and the adhesive layer (X1). delete In the first paragraph,
A peeling method in which a semiconductor wafer having a protective film attached in the above process (S1-1) is obtained by bonding a protective film forming film to a semiconductor wafer and then curing the protective film forming film. A method for peeling off a semiconductor chip with a protective film attached, comprising the following process (S1) and the following process (S2).
·Process (S1): Includes the following processes (S1-1) to (S1-2) in this order.
·Process (S1-1): A process of obtaining a semiconductor wafer with a protective film by attaching a semiconductor wafer to the protective film forming film side of a protective film forming laminate in which a protective film forming film is laminated on the adhesive layer (X1) of an adhesive sheet (X) having an adhesive layer (X1) and then curing the protective film forming film.
·Process (S1-2): A process of dicing the semiconductor wafer with the protective film attached to obtain a plurality of semiconductor chips with the protective film attached.
·Process (S2): A process of generating gas by sublimating at least a part of the protective film of some of the protective film-attached semiconductor chips among the plurality of protective film-attached semiconductor chips, and reducing the adhesive strength between some of the protective film-attached semiconductor chips and the adhesive layer (X1). In paragraph 4,
A peeling method in which the above adhesive sheet (X) is a dicing tape. In claim 1 or 4,
The above protective film of the semiconductor chip with the protective film attached is a protective film capable of absorbing laser light,
A peeling method, wherein the above process (S2) is performed by irradiating the laser light to at least a part of the protective film of the semiconductor chip having the protective film attached thereto. In claim 1 or 4,
A peeling method in which the following process (SP1) is performed before or after the above process (S2), and the following process (SP2) is performed after the below process (SP1) and also after the above process (S2).
·Process (SP1): A process of laminating the adhesive layer (Z1) of the transfer sheet (Z) having the adhesive layer (Z1) with the surface opposite to the protective film side of the plurality of protective film-attached semiconductor chips as the bonding surface, and laminating the adhesive layer (X1) and the transfer sheet (Z) with the plurality of protective film-attached semiconductor chips interposed therebetween.
·Process (SP2): A process of separating the transfer sheet (Z) and the adhesive layer (X1), peeling only the semiconductor chips with a protective film attached thereto from the adhesive layer (X1), and transferring the semiconductor chips with a protective film attached thereto onto the transfer sheet (Z). A method for manufacturing a semiconductor chip with a protective film, comprising a process for performing the method described in claim 1 or claim 4. A method for manufacturing a semiconductor device including a semiconductor chip with a protective film attached, comprising a process for performing the method described in claim 1 or claim 4.