TW202045651A - Expansion method and semiconductor device production method - Google Patents

Abstract

An expansion method comprising: adhering a first adhesive sheet (10) having a first adhesive layer (12) and a first substrate (11) to a second wafer surface of a wafer having a first wafer surface and a second wafer surface on the reverse side from the first wafer surface; making a cut starting from the first wafer surface side to dice the wafer into a plurality of chips (CP) and cut the first adhesive layer (12); separating the first substrate (11) from the first adhesive layer (12); adhering a second sheet (20) to the first adhesive layer (12); and stretching the second sheet (20) to widen the interval between the plurality of chips (CP).

Description

Extension method and manufacturing method of semiconductor device

The invention relates to an expansion method and a manufacturing method of a semiconductor device.

In recent years, electronic machines have progressed to miniaturization, light weight and high performance. Semiconductor devices mounted in electronic equipment are also required to be miniaturized, thinner, and high-density. Semiconductor chips are sometimes mounted in packages close to their size. These packages are also called Chip Scale Packages (CSP). As one of the CSPs, for example, a wafer level package (Wafer Level Package: WLP). In WLP, before singulation by dicing, external electrodes and the like are formed on the wafer, and finally the wafer is diced and singulated. As WLP, for example, fan-in (Fan-In) type and fan-out (Fan-Out) type. In fan-out WLP (hereinafter also referred to as "FO-WLP"), the semiconductor chip is covered with a sealing member in an area larger than the chip size to form a sealing body of the semiconductor chip, not only forming a rewiring layer and External electrodes are also formed on the surface area of the sealing member.

For example, Document 1 (International Publication No. 2010/058646) describes a plurality of semiconductor wafers singulated from semiconductor wafers, leaving the circuit formation surface, and using mold members to surround the surrounding to form an expanded wafer. A method of manufacturing a semiconductor package with a rewiring pattern formed by extending the outer area. In the manufacturing method described in Document 1, before the singulated plural semiconductor chips are surrounded by a mold member, they are replaced on the expansion wafer adhesive tape to extend the wafer adhesive tape so that the gap between the plural semiconductor chips The distance expands.

In addition, Document 2 (Japanese Patent Application Laid-Open No. 2017-076748) describes that a second base material layer, a first base material layer, and a first adhesive layer are sequentially provided, and the elongation at break of the second base material layer is 400 % Of adhesive flakes. The method of manufacturing a semiconductor device described in Document 2 includes a step of attaching a semiconductor wafer to the first adhesive layer of the adhesive sheet, a step of dicing the semiconductor wafer into pieces to form a plurality of semiconductor chips, and pulling The step of lengthening the adhesive sheet to expand the distance between semiconductor chips.

The tape used in the expansion step usually has an adhesive layer for fixing the semiconductor chip on the tape and a substrate supporting the adhesive layer. When the wafer adhesive tape for expansion is stretched as described in Document 1, not only the base material of the tape is stretched, but the adhesive layer is also stretched. After the expansion step, when the semiconductor wafer is peeled from the adhesive layer, there may be defects in the adhesive layer remaining on the surface of the semiconductor wafer in contact with the adhesive layer. These defects are sometimes referred to as remnants in this specification.

In addition, when the expansion step is performed using the adhesive sheet described in Document 2, since the adhesive layer in contact with the semiconductor wafer is not elongated, it is considered that it is difficult to generate a sticky layer. However, since the adhesive sheet described in Document 2 is composed of a tape composed of a second base material layer, a first base material layer, and a first adhesive layer layer, a simpler tape composition can be used to prevent the spread of residue. Looking forward eagerly. In addition, the process described in Document 2 is to cut the semiconductor wafer on the adhesive sheet without transferring it to other adhesive sheets, but directly stretch the adhesive sheet to perform the expansion step. Therefore, it is necessary to carefully control the cutting depth of the cutting blade in such a way that the cutting blade does not reach the second substrate layer during cutting. Therefore, it is also eagerly expected that the expansion method can be prevented by a simpler method.

In addition, in the expansion method, the adherend supported on the adhesive sheet is not only a semiconductor chip, but also semiconductor devices such as wafers, semiconductor device packages, and micro LEDs. These semiconductor devices are also similar to semiconductor wafers, and the distance between the semiconductor devices may be expanded.

The object of the present invention is to provide an expansion method that can simplify the tape structure and manufacturing process and suppress residual blur compared with the prior art, and provide a method of manufacturing a semiconductor device including the expansion method.

According to an aspect of the present invention, an expansion method is provided, which is attached to the second wafer surface of a wafer having a first wafer surface and a second wafer surface opposite to the first wafer surface A first adhesive sheet having a first adhesive layer and a first substrate is cut out from the first wafer surface side, the wafer is singulated into a plurality of chips, and the first adhesive layer is further cut The first substrate is peeled from the first adhesive layer, a second sheet is attached to the first adhesive layer, and the second sheet is stretched to expand the gap between the plurality of chips.

In the expansion method of one aspect of the present invention, it is preferable that the cut is formed to reach the depth of the first substrate. In the expansion method of an aspect of the present invention, it is preferable that the first adhesive layer contains a first energy ray curable resin. In the expansion method of one aspect of the present invention, the second sheet is preferably an expansion sheet. In the expansion method of one aspect of the present invention, it is preferable that the second sheet has a second adhesive layer and a second substrate, and the second adhesive layer contains a second energy ray curable resin. In the expansion method of one aspect of the present invention, it is preferable that the peeling force when the first base material is peeled from the first adhesive layer is 10 mN/25mm or more and 2000 mN/25mm or less. In the expansion method of one aspect of the present invention, it is preferable that the first adhesive sheet has a release layer between the first substrate and the first adhesive layer. In the expansion method of one aspect of the present invention, it is preferable that after the first substrate is peeled from the first adhesive layer, the plurality of chips to which the first adhesive layer is attached are held by a holding member and then pasted on The second sheet is attached to the first adhesive layer on the plurality of wafers held by the holding member. In the expansion method of one aspect of the present invention, it is preferable to singulate the wafer into a plurality of chips, and then stretch the first adhesive sheet to expand the interval between the plurality of chips. In the expansion method of one aspect of the present invention, the aforementioned wafer is preferably a semiconductor wafer. In the expansion method of one aspect of the present invention, it is preferable that the first wafer surface has a circuit. According to one aspect of the present invention, there is provided a method of manufacturing a semiconductor device, which includes an extension method.

According to one aspect of the present invention, it is possible to provide an expansion method that can simplify the structure and manufacturing process of the adhesive tape, and can suppress residual paste compared with the prior art. According to another aspect of the present invention, it is possible to provide a method of manufacturing a semiconductor device including an expansion method capable of suppressing residual blur.

[First Embodiment]

Hereinafter, the extension method of this embodiment and the manufacturing method of the semiconductor device including the extension method will be described. 1 (FIG. 1A and FIG. 1B), FIG. 2 (FIG. 2A and FIG. 2B), and FIG. 3 and FIG. 4 (FIG. 4A and FIG. 4B) are cross-sectional schematic diagrams illustrating the manufacturing method of the semiconductor device including the expansion method of this embodiment Figure. The extension method of this embodiment has at least the following steps (P1) to (P5). (P1) Prepare the step of attaching the first adhesive sheet to the second wafer surface of the wafer having the first wafer surface and the second wafer surface. The first adhesive sheet has a first adhesive layer and a first base material. (P2) A step of scribing a cut from the first wafer surface side, cutting the wafer, and further cutting at least the first adhesive layer to separate into a plurality of wafers. The first wafer surface becomes the circuit surface of the chip, and the second wafer surface becomes the back surface of the chip. (P3) The step of peeling off the first substrate with the first adhesive layer remaining on the back of the wafer. (P4) The step of attaching the second sheet to the first adhesive layer on the back side of the chip. (P5) The step of stretching the second sheet to enlarge the interval between a plurality of wafers. Fig. 1A is a diagram for explaining the step (P1). FIG. 1A shows a wafer W to which the first adhesive sheet 10 is attached.

The semiconductor wafer W has a circuit surface W1 as a first wafer surface and a back surface W3 as a second wafer surface. A circuit W2 is formed on the circuit surface W1. Paste the first adhesive sheet 10 on the back W3. In this embodiment, an example is described in which the circuit surface W1 is exposed and the process is performed. However, as an example of other aspects, for example, a protective member with a protective sheet or a protective film attached to the circuit surface W1 The state of the process. The first adhesive sheet 10 has a first adhesive layer 12 and a first base material 11. The details of the first adhesive sheet 10 will be described later. The semiconductor wafer W can be, for example, a silicon wafer, or a compound semiconductor wafer such as gallium and arsenic. As a method of forming the circuit W2 on the circuit surface W1 of the semiconductor wafer W, a widely used method is exemplified, such as an etching method and a peeling method.

[Back grinding step] The semiconductor wafer W prepared in step (P1) is preferably a wafer obtained through a back grinding step. In the back grinding step, the surface of the semiconductor wafer W on the opposite side to the circuit surface W1 is ground until the wafer has a specific thickness. The back surface W3 is preferably a surface formed by back grinding of the semiconductor wafer W. The surface exposed after the semiconductor wafer W is ground is the back surface W3. The method for grinding the semiconductor wafer W is not particularly limited, and for example, a conventional method using a grinder is used. When grinding the semiconductor wafer W, in order to protect the circuit W2, it is preferable to stick an adhesive sheet called a back grinding sheet on the circuit surface W1. The backside grinding of the wafer is to fix the circuit surface W1 side of the semiconductor wafer W by a fixture table etc., that is, the backside grinding sheet side, and to grind the backside side with no circuit formed by a grinder. The thickness of the semiconductor wafer W before grinding is not particularly limited, but is usually 500 μm or more and 1000 μm or less. The thickness of the semiconductor wafer W after grinding is not particularly limited, but is usually 20 μm or more and 500 μm or less.

[The first adhesive sheet pasting step] The semiconductor wafer W prepared in the step (P1) is preferably a wafer obtained through a back grinding step, and then a bonding step of pasting the first adhesive sheet 10 on the back side W3. This sticking step is sometimes called the sticking step of the first adhesive sheet. As described later, in the step (P2), the semiconductor wafer W is diced into a plurality of semiconductor wafers CP. In this embodiment, when the semiconductor wafer W is diced, in order to hold the semiconductor wafer W, it is preferable to stick the first adhesive sheet 10 to the back surface W3. The semiconductor wafer W is stuck on the back surface W3 toward the first adhesive layer 12 of the first adhesive sheet 10.

[Cutting step] Fig. 1B is a diagram for explaining the step (P2). Step (P2) is sometimes called the cutting step. FIG. 1B shows a plurality of semiconductor chips CP held on the first adhesive sheet 10. The semiconductor wafer W in the state where the first adhesive sheet 10 is pasted on the back surface W3 is diced and singulated to form a plurality of semiconductor chips CP. The circuit surface W1 as the first wafer surface corresponds to the circuit surface of the chip. The back surface W3 as the second wafer surface corresponds to the back surface of the wafer. In this embodiment, a cut is made from the circuit surface W1 side to cut the semiconductor wafer W, and furthermore, at least the first adhesive layer 12 of the first adhesive sheet 10 is cut. The first adhesive layer 12 is also cut to the same size as the semiconductor wafer CP. Cutting system uses cutting mechanism such as cutting saw or laser. The cutting depth at the time of dicing is not particularly limited as long as it is a depth at which the semiconductor wafer W and the first adhesive layer 12 can be singulated. In the present embodiment, a state in which the cutout to the first substrate 11 is not drawn is taken as an example for description, but the present invention is not limited to these aspects. For example, in other embodiments, based on the viewpoint of surely cutting the semiconductor wafer W and the first adhesive layer 12, it is also possible to form a cut with a depth up to the depth of the first substrate 11 by cutting. In addition, the dicing step of the present embodiment is to cut along the end surface of the semiconductor wafer W to form a cut in the first adhesive layer 12 as shown in FIG. 1B.

[Peeling step of the first substrate] Fig. 2A is a diagram for explaining the step (P3). This step (P3) is sometimes called the peeling step of the first substrate. 2A shows the step of peeling off the first base material 11 in a state where the first adhesive layer 12 remains on the back surface W3 of the singulated semiconductor chip CP after dicing. As one aspect of the first adhesive sheet 10, when the first adhesive layer 12 is directly laminated on the first substrate 11, in the peeling step of the first substrate, the first adhesive layer 12 is preferred The interface with the first substrate 11 peels off. When the first base material 11 is peeled off, a plurality of semiconductor wafers CP with the first adhesive layer 12 attached to the back surface W3 is obtained. Furthermore, in the peeling step of the first substrate of this embodiment, the first adhesive layer 12 that is not attached to the back surface W3 of the semiconductor chip CP is removed in a state of being attached to the first substrate 11 as shown in FIG. 2A. The peeling force when peeling the first base material 11 from the first adhesive layer 12 is preferably 10 mN/25 mm or more and 2000 mN/25 mm or less. By setting the peeling force when peeling the first base material 11 from the first adhesive layer 12 to 10 mN/25 mm or more, an effect of excellent semiconductor wafer retention during dicing is obtained. By setting the peeling force when peeling the first base material 11 from the first adhesive layer 12 to 2000 mN/25 mm or less, an effect of excellent pick-up of the diced semiconductor wafer is obtained. The peeling force when peeling the first base material 11 from the first adhesive layer 12 is more preferably 30 mN/25 mm or more and 1000 mN/25 mm or less, and still more preferably 50 mN/25 mm or more and 500 mN/25 mm or less. Using a precision universal testing machine ("Autograph AG-IS" manufactured by Shimadzu Corporation), the first base material was peeled from the first adhesive layer 12 under the conditions of a peeling angle of 180°, a measurement temperature of 23°C, and a stretching speed of 300 mm/min. In the tensile test of 11, the load measured during the tensile test is taken as the peel force.

[Paste the second sheet] Fig. 2B is a diagram for explaining the step (P4). Step (P4) is sometimes called the second sheet pasting step. FIG. 2B shows the state where the second sheet 20 is pasted on the plurality of semiconductor chips CP obtained by the dicing step. The second sheet 20 of this embodiment has a second adhesive layer 22 and a second base material 21. The details of the second sheet 20 will be described later. In the present embodiment, when the second sheet 20 is adhered to the back W3 side of the plurality of semiconductor chips CP, a singulated first adhesive is obtained between the plurality of semiconductor chips CP and the second adhesive layer 22 of the second sheet 20. The laminated structure of the agent layer 12.

[Extension steps] Fig. 3 is a diagram for explaining the step (P5). Step (P5) is sometimes called an expansion step. FIG. 3 shows a state where the second sheet 20 is stretched after the second sheet 20 is pasted to expand the gap between the plurality of semiconductor chips CP. When expanding the interval between the plurality of semiconductor chips CP, it is preferable to stretch the expansion sheet while maintaining the state of the plurality of semiconductor chips CP by an adhesive sheet called an expansion sheet. In this embodiment, the second sheet 20 is preferably an expanded sheet. The method of extending the second sheet 20 in the expansion step is not particularly limited. Examples of methods for stretching the second sheet 20 include pressing against an annular or circular expander to stretch the second sheet 20, and a method of pinching and stretching the outer periphery of the second sheet 20 using a holding member, etc. . In this embodiment, the interval D1 between the plurality of semiconductor chips CP is not particularly limited because it depends on the size of the semiconductor chip CP. In particular, the mutual distance D1 between the adjacent semiconductor chips CP of the plurality of semiconductor chips CP attached to one side of the adhesive sheet is preferably 200 μm or more. In addition, the upper limit of the mutual spacing of the semiconductor chips CP is not particularly limited. The upper limit of the mutual spacing of the semiconductor chips CP can be, for example, 6000 μm.

[First transfer step] In this embodiment, after the expansion step, the step of transferring the plurality of semiconductor chips CP adhered to the second sheet 20 to another adhesive sheet (for example, the third adhesive sheet) (hereinafter sometimes referred to as "the first transfer sheet") Printing steps"). FIG. 4A shows a diagram illustrating a step of transferring the plurality of semiconductor wafers CP adhered to the second sheet 20 to the third adhesive sheet 30 (hereinafter sometimes referred to as the "first transfer step"). The third adhesive sheet 30 is not particularly limited if it can hold a plurality of semiconductor chips CP. The third adhesive sheet 30 has a third base material 31 and a third adhesive layer 32. When it is desired to seal the plurality of semiconductor chips CP on the third adhesive sheet 30, as the third adhesive sheet 30, it is preferable to use an adhesive sheet for the sealing step, and it is more preferable to use an adhesive sheet having heat resistance. In addition, in the case of using an adhesive sheet having heat resistance as the third adhesive sheet 30, it is preferable that the third base material 31 and the third adhesive layer 32 are formed of heat-resistant materials that can withstand the temperature experienced in the sealing step. . When the transfer step is performed in this embodiment, it is preferable, for example, after the expansion step, to stick the third adhesive sheet 30 on the circuit surface W1 of the plurality of semiconductor chips CP, and then peel off the second sheet 20 and the first adhesive layer from the back surface W3 12. The second sheet 20 and the first adhesive layer 12 may be peeled from the back surface W3 together, or after the second sheet 20 is peeled off first, the first adhesive layer 12 may be peeled from the back surface W3. The step of peeling the first adhesive layer 12 from the back surface W3 may be referred to as the peeling step of the first adhesive layer.

After the peeling step of the first adhesive layer, it is also preferable to maintain the interval D1 between the plurality of semiconductor chips CP expanded in the expanding step. When peeling the first adhesive layer 12 from the back surface W3, it is preferable that the first adhesive layer 12 contains a first energy ray-curable resin from the viewpoint of suppressing residual paste on the back surface W3. When the first adhesive layer 12 contains a first energy ray curable resin, the first adhesive layer 12 is irradiated with energy rays to cure the first energy ray curable resin. When the first energy ray curable resin is cured, the cohesive force of the first adhesive layer 12 increases, and the adhesive force between the first adhesive layer 12 and the back surface W3 of the semiconductor chip CP can be reduced or eliminated. As the energy rays, for example, ultraviolet rays (UV) and electron beams (EB) are exemplified, and ultraviolet rays are preferable. Therefore, the first energy ray curable resin is preferably an ultraviolet curable resin.

Based on the viewpoint that the second sheet 20 and the first adhesive layer 12 are peeled from the back surface W3, when the second sheet 20 includes the second adhesive layer 22, the second adhesive layer 22 preferably contains a second energy ray hardening性resin. When the first adhesive layer 12 contains the first energy ray curable resin and the second adhesive layer 22 contains the second energy ray curable resin, the second adhesive layer 22 and the first The adhesive layer 12 is irradiated with energy rays to harden the second energy ray curable resin and the first energy ray curable resin. As the energy ray for curing the second energy curable resin, for example, ultraviolet light (UV) and electron beam (EB) are exemplified, and ultraviolet light is preferable. Therefore, the second energy ray curable resin is preferably an ultraviolet curable resin. The second substrate 21 preferably has energy ray permeability. As a different aspect from this embodiment, the first adhesive layer 12 may be used as a protective film for protecting the back surface W3 of the semiconductor chip CP without being peeled off from the back surface W3 of the semiconductor chip CP. When the first adhesive layer 12 is used as a protective film for the back surface W3, the first adhesive layer 12 preferably contains a curable adhesive composition. The third adhesive sheet 30 may be attached to the ring frame together with the plurality of semiconductor chips CP. In this case, a ring frame is placed on the third adhesive layer 32 of the third adhesive sheet 30, and the ring frame is gently pressed and fixed. Subsequently, the third adhesive layer 32 exposed inside the ring shape of the ring frame is pressed against the circuit surface W1 of the semiconductor chip CP to fix the plurality of semiconductor chips CP to the third adhesive sheet 30. Alternatively, the third adhesive layer 32 exposed inside the ring shape of the ring frame is pressed against the first adhesive layer 12 on the back W3 of the semiconductor chip CP to fix the plurality of semiconductor chips CP to the third adhesive sheet 30. At this time, the first adhesive layer 12 is interposed between the back surface W3 of the semiconductor chip CP and the third adhesive layer 32.

[Sealing step] FIG. 4B shows a diagram illustrating a step of sealing a plurality of semiconductor wafers CP using the sealing member 300 (hereinafter sometimes referred to as a "sealing step"). In this embodiment, the sealing step is performed after transferring the plurality of semiconductor wafers CP to the third adhesive sheet 30. In the sealing step, in a state where the circuit surface W1 is protected by the third adhesive sheet 30, the sealing body 3 is formed by covering the plurality of semiconductor chips CP with the sealing member 300. The sealing member 300 is also filled between the plurality of semiconductor chips CP. Since the circuit surface W1 and the circuit W2 are covered by the third adhesive sheet 30, it is possible to prevent the sealing member 300 from covering the circuit surface W1.

Through the sealing step, a sealing body 3 in which a plurality of semiconductor chips CP separated by a certain distance are embedded in the sealing member 300 is obtained. In the sealing step, the plurality of semiconductor chips CP are preferably covered by the sealing member 300 to maintain the state of the interval D1 after the expansion step is performed. After the sealing step, the third adhesive sheet 30 is peeled off. When the third adhesive sheet 30 is peeled off, the circuit surface W1 of the semiconductor chip CP and the surface 3A of the sealing body 3 contacting the third adhesive sheet 30 are exposed. After the aforementioned expansion step, by repeating the transfer step and the expansion step an arbitrary number of times, the distance between the semiconductor wafers CP is set to a desired distance, and the direction of the circuit surface when the semiconductor wafer CP is sealed can be set to the desired direction.

[Other steps] After peeling off the adhesive sheet from the sealing body 3, the sealing body 3 is sequentially subjected to a rewiring layer forming step to form a rewiring layer electrically connected to the semiconductor chip CP and a connecting step to electrically connect the rewiring layer to the external terminal electrode . The circuit of the semiconductor chip CP and the external terminal electrode are electrically connected through the rewiring layer forming step and the connection step with the external terminal electrode. The sealing body 3 to which the external terminal electrode is connected is singulated by semiconductor chip CP units. The method of singulating the sealing body 3 into pieces is not particularly limited. By singulating the sealing body 3 into pieces, a semiconductor package of the semiconductor chip CP unit is manufactured. The semiconductor package in which fan-out external electrodes are connected outside the area of the semiconductor chip CP is manufactured as a fan-out wafer level package (FO-WLP).

(The first adhesive sheet) The first adhesive sheet 10 has a first base material 11 and a first adhesive layer 12. The first adhesive layer 12 is laminated on the first base material 11. ・First base material The first base material 11 of the present embodiment is not particularly limited as long as it can exhibit an appropriate function in a desired step. The first substrate 11 is a member that supports the first adhesive layer 12. The first substrate 11 is, for example, a resin film. As the resin film, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate are used. Diester film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene and (methyl) ) At least one film selected from the group consisting of acrylic copolymer film, ethylene/(meth)acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film and fluororesin film. Furthermore, as the first substrate 11, these crosslinked films are also used. Furthermore, the first substrate 11 may be such a laminated film.

In addition, the first substrate 11 may be, for example, a rigid support. The material of the rigid support may be appropriately determined in consideration of mechanical strength and heat resistance. Examples of hard support materials are metal materials such as SUS; non-metallic inorganic materials such as glass and silicon wafers; epoxy, ABS, acrylic, engineering plastics, super engineering plastics, polyimide, and polyamide Resin materials such as amines; composite materials such as glass epoxy resins, etc. Among them, SUS, glass and silicon wafers are preferred. Examples of engineering plastics include nylon, polycarbonate (PC), and polyethylene terephthalate (PET). Examples of super engineering plastics include polyphenylene sulfide (PPS), polyether sulfide (PES), and polyether ether ketone (PEEK). The thickness of the first substrate 11 is not particularly limited. The thickness of the first substrate 11 is preferably 20 μm or more and 50 mm or less, more preferably 60 μm or more and 20 mm or less. By setting the thickness of the first base material 11 in the above range, when the first base material 11 is a resin film, since the first adhesive sheet 10 has sufficient flexibility, it shows good adhesion to the processing object (workpiece). Attached. The object to be processed (workpiece) is, for example, a wafer or a semiconductor element, and a more specific example is a semiconductor wafer or a semiconductor wafer. When the first base material 11 is a hard support, the thickness of the hard support may be appropriately determined in consideration of mechanical strength, handling properties, and the like. The thickness of the rigid support is, for example, 100 μm or more and 50 mm or less.

・The first adhesive layer The constituent material of the first adhesive layer 12 is not particularly limited as long as it can exhibit an appropriate function in a desired step. In one aspect of the first adhesive layer 12, it is preferably made of, for example, acrylic adhesives, urethane adhesives, polyester adhesives, rubber adhesives, and silicone adhesives. It is composed of at least one adhesive selected from the group, more preferably composed of an acrylic adhesive. One aspect of the first adhesive layer 12 preferably contains a curable adhesive composition which receives energy rays from the outside and hardens. Examples of energy supplied from the outside include ultraviolet rays, electron beams, and heat. The first adhesive layer 12 preferably contains at least one of an ultraviolet curable adhesive and a thermosetting adhesive. When the first base material 11 has heat resistance, the adhesive layer is preferably a thermosetting adhesive layer containing a thermosetting adhesive because it can suppress the occurrence of residual stress during thermal curing.

The first adhesive layer 12 contains, for example, a first adhesive composition. The first adhesive composition contains a binder polymer component (A) and a curable component (B). (A) Binder polymer composition In order to impart sufficient adhesiveness and film forming properties (sheet-forming properties) to the first adhesive layer 12, the adhesive polymer component (A) is used. As the binder polymer component (A), conventionally known acrylic polymers, polyester resins, urethane resins, acrylic urethane resins, silicone resins, rubber-based polymers, etc. can be used. The weight average molecular weight (Mw) of the binder polymer component (A) is preferably 10,000 or more and 2 million or less, more preferably 100,000 or more and 1.2 million or less. In this specification, the weight average molecular weight (Mw) is a standard polystyrene conversion value measured by the Gel Permeation Chromatography (GPC) method. As the binder polymer component (A), an acrylic polymer is preferably used. The glass transition temperature (Tg) of the acrylic polymer is preferably -60°C or higher and 50°C or lower, more preferably -50°C or higher and 40°C or lower, and still more preferably in the range of -40°C or higher and 30°C or lower.

Examples of the monomer constituting the above-mentioned acrylic polymer include (meth)acrylate monomers or derivatives thereof. For example, alkyl (meth)acrylates with the carbon number of the alkyl group being 1-18, specific examples are methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, (meth) Butyl acrylate, 2-ethylhexyl (meth)acrylate, etc. Also, examples are (meth)acrylates having a cyclic skeleton, specifically cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, di(meth)acrylate Cyclopentyl ester, dicyclopentenyl (meth)acrylate, dicyclopentenoxyethyl (meth)acrylate, imide (meth)acrylate, and the like. Further examples of monomers having functional groups include hydroxymethyl (meth)acrylate having hydroxyl groups, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc.; in addition, examples include Epoxy glycidyl (meth)acrylate, etc. The acrylic polymer is preferably an acrylic polymer containing a monomer having a hydroxyl group because it has good compatibility with the curable component (B) described later. In addition, the above-mentioned acrylic polymer may also be copolymerized with at least one selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, and styrene, for example. Furthermore, as the adhesive polymer component (A), a thermoplastic resin for maintaining the flexibility of the film of the first adhesive layer 12 after curing may be formulated. Such thermoplastic resins are preferably resins with a weight average molecular weight of 1,000 or more and 100,000 or less, and more preferably 3,000 or more and 80,000 or less. The glass transition temperature of the thermoplastic resin is preferably -30°C or higher and 120°C or lower, more preferably -20°C or higher and 120°C or lower. Examples of the thermoplastic resin include polyester resin, urethane resin, phenoxy resin, polybutene, polybutadiene, or polystyrene. These thermoplastic resins can be used individually by 1 type or in combination of 2 or more types.

(B) Hardening ingredients The curable component (B) uses at least one of a thermosetting component and an energy ray curable component. As the curable component (B), a thermosetting component and an energy ray curable component can also be used. As the thermosetting component, a thermosetting resin and a thermosetting agent are used. The thermosetting resin is preferably epoxy resin. As the epoxy resin, conventionally known epoxy resins can be used. Specific examples of epoxy resins are polyfunctional epoxy resins, or bisphenol A diglycidyl ether or its hydride, o-cresol novolac epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type ring Oxygen resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenylene skeleton type epoxy resins, and other epoxy compounds that have more than two functions in the molecule These can be used individually by 1 type or in combination of 2 or more types. In the first adhesive layer 12, relative to 100 parts by mass of the adhesive polymer component (A), the thermosetting resin preferably contains 1 part by mass to 1000 parts by mass, more preferably 10 parts by mass to 500 parts by mass, and More preferably, it is 20 parts by mass or more and 200 parts by mass or less. If the content of the thermosetting resin is 1 part by mass or more, the disadvantage that sufficient adhesiveness cannot be obtained can be suppressed. If the content of the thermosetting resin is 1000 parts by mass or less, the peeling force between the first adhesive layer 12 and the first base material 11 can be prevented from becoming too high. If the peeling force is prevented from becoming too high, it is possible to prevent transfer failure of the first adhesive layer 12 to the back surface W3 of the semiconductor wafer CP.

The thermosetting agent functions as a curing agent for thermosetting resins, especially epoxy resins. As a preferable thermosetting agent, a compound having two or more functional groups that can react with epoxy groups in one molecule is exemplified. Examples of functional groups that can react with epoxy groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and acid anhydride groups. Among these, phenolic hydroxyl group, amino group, acid anhydride group, etc. are preferred, and phenolic hydroxyl group and amino group are more preferred. Specific examples of phenolic hardeners include polyfunctional phenol resins, bisphenols, novolac phenol resins, dicyclopentadiene phenol resins, Xyloc phenol resins, and aralkylphenol resins. As a specific example of the amine curing agent, DICY (dicyanodiamide) is exemplified. These thermosetting agents may be used individually by 1 type, or may be used in combination of 2 or more types. The content of the thermosetting agent is preferably not less than 0.1 part by mass and not more than 500 parts by mass, and more preferably not less than 1 part by mass and not more than 200 parts by mass relative to 100 parts by mass of the thermosetting resin. When the first adhesive layer 12 contains a thermosetting component as the curable component (B), the first adhesive layer 12 has thermosetting properties. In this case, the first adhesive layer 12 can be cured by heating, but in the first adhesive sheet 10 of this embodiment, when the first base material 11 has heat resistance, the first adhesive layer 12 is thermally cured In this case, it is unlikely that residual stress will be generated on the base material to cause defects.

As the energy-ray curable component, a low-molecular compound (energy-ray polymerizable compound) that contains an energy-ray polymerizable group and polymerizes and hardens when irradiated with energy rays such as ultraviolet rays or electron beams can be used. Specific examples of such energy ray curable components are trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxy pentaacrylate, dipentaerythritol hexaacrylate, or 1,4-butane Alcohol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, oligopolyester acrylate, urethane acrylate oligomer, epoxy modified acrylate, poly Acrylic compounds such as ether acrylate and itaconic acid oligomer. These compounds have at least one polymerizable double bond in the molecule, and usually have a weight average molecular weight of 100 or more and 30,000 or less, preferably 300 or more and 10,000 or less. The blending amount of the energy ray polymerizable compound is preferably 1 part by mass or more and 1500 parts by mass or less, more preferably 10 parts by mass or more and 500 parts by mass or less, with respect to 100 parts by mass of the binder polymer component (A) It is 20 parts by mass or more and 200 parts by mass or less. In addition, as the energy ray curable component, it is sufficient to use an energy ray curable polymer formed by bonding an energy ray polymerizable group to the main chain or side chain of the binder polymer component (A). These energy-ray curable polymers have both the function of the binder polymer component (A) and the function of the curable component (B).

The main skeleton of the energy ray hardening polymer is not particularly limited. It can be an acrylic polymer widely used as the binder polymer component (A), and can also be polyester, polyether, etc., but it is easy to synthesize and control For physical properties, acrylic polymer is preferred as the main skeleton. The energy ray polymerizable group bonded to the main chain or side chain of the energy ray hardening polymer is, for example, a group containing energy ray polymerizable carbon-carbon double bonds, and specific examples include (meth)acrylic acid groups. The energy ray polymerizable group may be bonded to the energy ray curable polymer via an alkylene group, an alkoxy group, and a polyalkylene group. The weight average molecular weight (Mw) of the energy ray curable polymer to which the energy ray polymerizable group is bonded is preferably 10,000 or more and 2 million or less, more preferably 100,000 or more and 1.5 million or less. In addition, the glass transition temperature (Tg) of the energy ray hardening polymer is preferably -60°C or higher and 50°C or lower, more preferably -50°C or higher and 40°C or lower, and still more preferably -40°C or higher and 30°C or lower. The energy ray curable polymer is obtained by reacting, for example, an acrylic polymer containing a functional group and a compound containing a polymerizable group. Examples of the functional group possessed by the functional group-containing acrylic polymer include, for example, a hydroxyl group, a carboxyl group, an amino group, a substituted amine, and an epoxy group. The polymerizable group-containing compound is a polymerizable group-containing compound having 1 to 5 substituent groups that react with the substituent groups of the acrylic polymer and energy-ray polymerizable carbon-carbon double bonds per molecule. Examples of the substituent that reacts with the functional group include an isocyanate group, a glycidyl group, and a carboxyl group.

Examples of polymerizable group-containing compounds include (meth)acryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, (meth)acryloyl isocyanate, and allyl Isocyanate, glycidyl (meth)acrylate and (meth)acrylic acid, etc. The acrylic polymer is preferably a (meth)acrylic monomer or its derivative having functional groups such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group, and other (meth)acrylates that can be copolymerized therewith A copolymer of monomers or their derivatives. Examples of (meth)acrylic monomers or derivatives thereof having functional groups such as hydroxyl, carboxyl, amino, substituted amino, epoxy, etc. are, for example, 2-hydroxyethyl (meth)acrylate having hydroxyl, ( 2-hydroxypropyl meth)acrylate; acrylic acid, methacrylic acid, and itaconic acid with carboxyl group; glycidyl methacrylate and glycidyl acrylate with epoxy group. Examples of other (meth)acrylate monomers or derivatives thereof that can be copolymerized with the above-mentioned (meth)acrylic monomers are, for example, alkyl (meth)acrylates with an alkyl group of 1 to 18 carbon atoms. Specific examples are These include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and the like. Examples of other (meth)acrylate monomers or derivatives thereof that can be copolymerized with the above-mentioned (meth)acrylic monomers are (meth)acrylates having a cyclic skeleton, specifically cyclohexane (meth)acrylate Ester, benzyl (meth)acrylate, isobornyl acrylate, dicyclopentyl acrylate, dicyclopentenyl acrylate, dicyclopentenoxyethyl acrylate, imide acrylate, etc. In addition, the aforementioned acrylic polymer may be copolymerized with at least one selected from the group consisting of vinyl acetate, acrylonitrile, and styrene, for example.

Even in the case of using an energy-ray curable polymer, the aforementioned energy-ray polymerizable compound may be used in combination, and the binder polymer component (A) may also be used in combination. In the present embodiment, the relationship between the amounts of the three components in the first adhesive layer 12 is 100 parts by mass relative to the total mass of the energy ray hardening polymer and the adhesive polymer component (A). The energy ray polymerization The sexual compound is preferably from 1 part by mass to 1500 parts by mass, more preferably from 10 parts by mass to 500 parts by mass, and still more preferably from 20 parts by mass to 200 parts by mass. By imparting energy ray curability to the first adhesive layer 12, the first adhesive layer 12 can be cured easily and in a short time, thereby improving the production efficiency of the cured film-attached wafer. The cured film can function as a protective film for protecting semiconductor elements. In the past, protective films for semiconductor devices such as chips are generally formed by thermosetting resins such as epoxy resins. However, the curing temperature of thermosetting resins exceeds 200°C and the curing time takes about 2 hours, which improves production efficiency. Obstacles. However, since the energy-ray curable adhesive layer is cured in a short time by irradiation with energy rays, a protective film can be easily formed, which can help improve production efficiency.

・Other ingredients The first adhesive layer 12 may contain the following components in addition to the above-mentioned adhesive polymer component (A) and curable component (B). (C) Coloring agent The first adhesive layer 12 contains a coloring agent (C) in one aspect. Since the coloring agent is blended in the first adhesive layer 12, when the first adhesive layer 12 is hardened to become the protective film of the semiconductor chip CP, when the semiconductor device is assembled in the machine, the protective film will shield the surrounding devices. Infrared rays, etc., can prevent malfunctions of semiconductor devices caused by such infrared rays. In addition, the visibility of characters when the product number or the like is printed on the cured film (protective film) obtained by curing the first adhesive layer 12 containing the colorant (C) is improved. That is, on the semiconductor device or semiconductor chip on which the protective film is formed, the product number and the like are usually printed on the surface of the protective film by the laser marking method (a method of cutting off the surface of the protective film by laser light to perform printing). When the protective film contains the coloring agent (C), the contrast between the laser-cut part and the uncut part of the protective film can be sufficiently obtained to improve visibility. As the coloring agent (C), at least any one of organic pigments, inorganic pigments, organic dyes, and inorganic dyes is used. As the colorant (C), a black pigment is preferred from the viewpoint of electromagnetic wave or infrared shielding properties. As the black pigment system, carbon black, iron oxide, manganese dioxide, aniline black, activated carbon, etc. are used, but are not limited to these. From the viewpoint of improving the reliability of semiconductor devices, carbon black is particularly preferred as the colorant (C). The coloring agent (C) may be used individually by 1 type, and may be used in combination of 2 or more types. The high curability of the first adhesive layer 12 in this embodiment is particularly useful when using a coloring agent that reduces the transmittance of at least any one of visible light and infrared rays and both ultraviolet rays to reduce the transmittance of ultraviolet rays. Can play better. As a coloring agent that reduces the transmittance of at least any one of visible light and infrared rays and ultraviolet rays, in addition to the above-mentioned black pigments, if it has absorption in the wavelength region of at least one of visible light and infrared rays and both ultraviolet rays The coloring agent, which is sexual or reflective, is not particularly limited. The compounding amount of the colorant (C) is preferably 0.1 parts by mass or more and 35 parts by mass or less, and more preferably 0.5 parts by mass or more and 25 parts by mass or less relative to 100 parts by mass of the total solid content constituting the first adhesive layer 12, More preferably, it is 1 part by mass or more and 15 parts by mass or less.

(D) Hardening accelerator The hardening accelerator (D) is used to adjust the hardening speed of the first adhesive layer 12. The hardening accelerator (D) is particularly preferably used when an epoxy resin and a thermosetting agent are used in combination with the hardening component (B). Examples of preferable hardening accelerators are tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol, etc.; 2- Methyl imidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethyl Imidazoles such as ylimidazole; organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine; tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, etc. Base borate and so on. These hardening accelerators may be used alone or in combination of two or more kinds. The curing accelerator (D) is preferably contained in an amount of 0.01 parts by mass or more and 10 parts by mass or less, and more preferably 0.1 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the curable component (B).

(E) Coupling agent The coupling agent (E) is used in order to improve at least any one of the adhesion and adhesion of the first adhesive layer 12 to the semiconductor element, and the cohesiveness of the cured film (protective film). In addition, by using the coupling agent (E), the heat resistance of the cured film (protective film) obtained by curing the first adhesive layer 12 is not impaired, and the water resistance can be improved. As the coupling agent (E), it is preferable to use a compound having a group that reacts with functional groups such as the binder polymer component (A) and the curable component (B). As the coupling agent (E), a silane coupling agent is desirable. Examples of these coupling agents are γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethane Trimethoxysilane, γ-(methacryloxypropyl) trimethoxysilane, γ-aminopropyl trimethoxysilane, N-6-(aminoethyl)-γ-aminopropyl Trimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyl diethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-urea Propyl propyl triethoxy silane, γ-mercaptopropyl trimethoxy silane, γ-mercaptopropyl methyl dimethoxy silane, bis (3-triethoxy silyl propyl) tetrasulfide, methyl Trimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, imidazolesilane, etc. These coupling agents (E) may be used individually by 1 type, or may mix and use 2 or more types. Coupling agent (E) is usually 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.2 parts by mass or more and 10 parts by mass relative to 100 parts by mass of the total of the binder polymer component (A) and curable component (B) Hereinafter, it is more preferable to contain 0.3 parts by mass or more and 5 parts by mass or less.

(F) Inorganic filler By blending the inorganic filler (F) in the first adhesive layer 12, the thermal expansion coefficient of the cured film (protective film) after curing can be adjusted. Examples of preferred inorganic fillers include powders of silica, alumina, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, and boron nitride, such spherical beads, single crystal fibers, and glass fibers. Wait. Among these inorganic fillers, silica fillers and alumina fillers are preferred. The above-mentioned inorganic filler (F) may be used alone or in combination of two or more kinds. The content of the inorganic filler (F) can usually be adjusted within the range of 1 part by mass to 80 parts by mass relative to 100 parts by mass of the total solid content constituting the adhesive layer.

(G) Photopolymerization initiator When the first adhesive layer 12 contains an energy-ray curable component as the aforementioned curable component (B), it is irradiated with energy rays such as ultraviolet rays during use to harden the energy-ray curable component. At this time, since the photopolymerization initiator (G) is contained in the composition constituting the first adhesive layer 12, the polymerization curing time can be shortened, and the amount of light irradiation can be reduced. Specific examples of these photopolymerization initiators (G) are benzophenone, acetophenone, benzil, benzyl methyl ether, benzyl ethyl ether, benzyl isopropyl ether, and benzyl isobutyl. Ether, benzyl benzoic acid, benzyl methyl benzoate, benzyl dimethyl acetal, 2,4-diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, benzyl diphenyl Sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, biphenyl, biphenyl, biphenyl, 1,2-diphenylmethane, 2-hydroxy-2-methyl -1-[4-(1-methylvinyl)phenyl]acetone, 2,4,6-trimethylbenzyldiphenylphosphine oxide, β-chloroanthraquinone, etc. The photopolymerization initiator (G) may be used alone or in combination of two or more kinds. The blending ratio of the photopolymerization initiator (G) is preferably 0.1 part by mass or more and 10 parts by mass or less, and more preferably 1 part by mass or more and 5 parts by mass or less relative to 100 parts by mass of the energy ray curable component. If the compounding ratio of the photopolymerization initiator (G) is 0.1 parts by mass or more, it is possible to prevent the defect of insufficient transferability due to insufficient photopolymerization. If the blending ratio of the photopolymerization initiator (G) is 10 parts by mass or less, it is possible to prevent the generation of residues that do not contribute to photopolymerization and the defect that the curability of the first adhesive layer 12 becomes insufficient.

(H) Crosslinking agent In order to adjust the initial adhesive force and cohesive force of the first adhesive layer 12, a cross-linking agent may be added to the first adhesive layer 12. Examples of the crosslinking agent (H) include organic polyvalent isocyanate compounds and organic polyvalent imine compounds. As the above-mentioned organic polyisocyanate compound, there can be exemplified aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds and trimers of these organic polyisocyanate compounds, as well as these organic polyisocyanate compounds and polyisocyanate compounds. Terminal isocyanate urethane prepolymer obtained by reaction of alcohol compound, etc. Examples of organic polyvalent isocyanate compounds include, for example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, and diphenylmethane-4,4 '-Diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4 '-Diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, trimethylolpropane add toluene diisocyanate and lysine isocyanate. Examples of the above-mentioned organic polyimine compound are N,N'-diphenylmethane-4,4'-bis(1-aziridine carboxyamide), trimethylolpropane-tris-β-aziridinyl Propionate, tetramethylolmethane-tris-β-aziridinyl propionate and N,N'-toluene-2,4-bis(1-aziridine carboxyamide) triethylene melamine, etc. . The crosslinking agent (H) is usually used in a ratio of 0.01 parts by mass to 20 parts by mass, and preferably 0.1 parts by mass or more, relative to the total of 100 parts by mass of the binder polymer component (A) and the energy ray curable polymer It is used in a ratio of 10 parts by mass or less, and more preferably in a ratio of 0.5 parts by mass to 5 parts by mass.

(I) Widely used additives In addition to the above, various additives may be blended in the first adhesive layer 12 as needed. Examples of various additives include leveling agents, plasticizers, antistatic agents, antioxidants, ion trapping agents, aggregating agents, and chain transfer agents. The first adhesive layer composed of the above-mentioned components has adhesiveness and curability, and can be easily adhered by pressing the workpiece (semiconductor wafer or chip, etc.) in the uncured state. In addition, the first adhesive layer 12 may have a single-layer structure, or may have a multilayer structure as long as it contains one or more layers containing the above-mentioned components. The thickness of the first adhesive layer 12 is not particularly limited. The thickness of the first adhesive layer 12 is preferably 3 μm or more and 300 μm or less, more preferably 5 μm or more and 250 μm or less, and still more preferably 7 μm or more and 200 μm or less. The above is the description of the first adhesive layer 12.

・Peeling sheet A release sheet can be attached to the surface of the first adhesive sheet 10. Specifically, the release sheet is attached to the surface of the first adhesive layer 12 of the first adhesive sheet 10. The release sheet is attached to the surface of the first adhesive layer 12 to protect the first adhesive layer 12 during transportation and storage. The release sheet is releasably attached to the first adhesive sheet 10, and is peeled and removed from the first adhesive sheet 10 before the first adhesive sheet 10 is used. The peeling sheet is a peeling sheet with at least one surface subjected to a peeling treatment. Specifically, for example, a release sheet provided with a release sheet substrate and a release agent layer formed by applying a release agent on the surface of the substrate. The base material for the release sheet is preferably a resin film. Examples of resins constituting the resin film of the base material for the release sheet include polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin. And polyolefin resins such as polypropylene resin and polyethylene resin. Examples of release agents include rubber elastomers such as silicone resins, olefin resins, isoprene resins, butadiene resins, long-chain alkyl resins, alkyd resins, and fluorine resins. . The thickness of the release sheet is not particularly limited, but is preferably from 10 μm to 200 μm, more preferably from 20 μm to 150 μm.

The first adhesive sheet is not limited to the sheet structure shown in FIG. 1A. Depending on the type of the first adhesive layer, there may be a better combination of the first substrate and the first adhesive layer. For example, when the first adhesive layer is an uncured adhesive layer, the first substrate is a resin film alone, or may be the aforementioned release sheet. When the aforementioned release sheet is used as the first substrate, the first adhesive layer is preferably laminated on the release agent layer. For example, when the first adhesive layer is a curable adhesive layer, the first substrate is a resin film alone, or may be the aforementioned release sheet. When the aforementioned release sheet is used as the first substrate, the first adhesive layer is preferably laminated on the release agent layer. In addition, when the first adhesive layer is a curable adhesive layer, the first adhesive sheet is preferably between the first substrate and the curable first adhesive layer and has another curable adhesive layer (with When called the fourth adhesive layer). The curable fourth adhesive layer preferably contains a conventional curable adhesive or the curable adhesive described in this specification. The first adhesive layer and the fourth adhesive layer preferably have different compositions. When the cured film of the first adhesive layer is used as a protective film to protect the back of a semiconductor chip, the first adhesive layer and the fourth adhesive layer can be cured, which can be easily applied to the cured film of the first adhesive layer and the fourth adhesive layer. The interface of the hardened film of the adhesive layer is peeled off.

・Method of manufacturing adhesive sheet The manufacturing method of the first adhesive sheet 10 and other adhesive sheets described in this specification is not particularly limited, and can be manufactured by a conventional method. For example, the adhesive layer provided on the release sheet is attached to one side of the substrate, and the adhesive sheet with the release sheet attached to the surface of the adhesive layer can be manufactured. Moreover, the buffer layer provided on the release sheet is attached to the base material, and the release sheet is removed to obtain a laminate of the buffer layer and the base material. Moreover, the adhesive layer provided on the release sheet is attached to the substrate side of the laminate, and an adhesive sheet with the release sheet attached to the surface of the adhesive layer can be manufactured. In addition, when the buffer layer is provided on both sides of the substrate, the adhesive layer is formed on the buffer layer. The peeling sheet attached to the surface of the adhesive layer can be properly peeled and removed before the adhesive sheet is used. As a more specific example of the manufacturing method of the adhesive sheet, the following method is exemplified. First, the adhesive composition constituting the adhesive layer and the coating solution containing a solvent or a dispersion medium as desired are prepared. Secondly, the coating liquid is applied to one surface of the substrate by the coating mechanism to form a coating film. As the coating mechanism, for example, die nozzle coater, curtain coater, spray coater, slit coater, knife coater, etc. are exemplified. Secondly, by drying the coating film, an adhesive layer can be formed. If the coating liquid can be applied, its properties are not particularly limited. The coating solution may also contain components for forming the adhesive layer as a solute, and may also contain components for forming the adhesive layer as a dispersion medium. Similarly, the adhesive composition can also be directly coated on one side of the substrate or the buffer layer to form an adhesive layer. Also, as another more specific example of the manufacturing method of the adhesive sheet, the following method is exemplified. First, a coating liquid is applied to the release surface of the release sheet to form a coating film. Next, the coating film is dried to form a laminate composed of the adhesive layer and the release sheet. Secondly, by attaching the substrate to the surface of the adhesive layer of the laminate on the side opposite to the side of the release sheet, a laminate of the adhesive sheet and the release sheet can also be obtained. The peeling sheet in the laminated body can also be used as a step material to be peeled off to protect the adhesive layer before the adherend (such as semiconductor wafers and semiconductor wafers) is attached to the adhesive layer.

In the case that the coating liquid contains a crosslinking agent, if the coating film drying conditions (such as temperature and time, etc.) are changed, or by additional heat treatment, for example, the (meth)acrylic copolymer in the coating film The cross-linking reaction with the cross-linking agent is sufficient to form a cross-linked structure at a desired density in the adhesive layer. In order to fully carry out the cross-linking reaction, after laminating the adhesive layer on the substrate by the above method, the resulting adhesive sheet can also be allowed to stand for several days in an environment of, for example, 23° C. and 50% relative humidity. The thickness of the first adhesive sheet 10 is preferably 40 μm or more, more preferably 60 μm or more. The thickness of the first adhesive sheet 10 is preferably 200 μm or less, more preferably 150 μm or less.

(Second sheet) The second sheet 20 has a second base material 21 and a second adhesive layer 22. The second adhesive layer 22 is laminated on the second base material 21. ・Second base material The material of the second base material 21 is not particularly limited as long as it exhibits an appropriate function in a desired step such as an expansion step. The aforementioned second substrate 21 preferably has a first substrate surface and a second substrate surface opposite to the first substrate surface. In the second sheet 20, the second adhesive layer 22 is preferably provided on one of the first substrate surface and the second substrate surface, and the adhesive layer is preferably not provided on the other surface. From the viewpoint of being easily extended to a large extent, the material of the second substrate 21 is preferably a thermoplastic elastomer or a rubber-based material, and more preferably a thermoplastic elastomer. In addition, from the viewpoint of being easily extended to a large extent, it is preferable to use a resin having a relatively low glass transition temperature (Tg) as the material of the second substrate 21. The glass transition temperature (Tg) of these resins is preferably 90°C or less, more preferably 80°C or less, and still more preferably 70°C or less. Examples of thermoplastic elastomers include urethane-based elastomers, olefin-based elastomers, vinyl chloride-based elastomers, polyester-based elastomers, styrene-based elastomers, acrylic-based elastomers, and amide-based elastomers. A thermoplastic elastomer may be used individually by 1 type, or may be used in combination of 2 or more types. As the thermoplastic elastomer, a urethane-based elastomer is preferably used from the viewpoint of being easily extended to a large extent.

Urethane-based elastomers are generally obtained by reacting long-chain polyols, chain extenders, and diisocyanates. The urethane-based elastic system is composed of a soft segment and a hard segment. The soft segment has a structural unit derived from a long-chain polyol. The hard segment has a polyurethane formed by the reaction of a chain extender and a diisocyanate. Ester structure. Urethane-based elastomers are classified according to the types of long-chain polyols. They are classified into polyester-based polyurethane elastomers, polyether-based polyurethane elastomers, and polycarbonate-based polyamines. Base formate elastomers, etc. In this embodiment, the urethane elastomer is preferably a polyether-based polyurethane elastomer from the viewpoint of being easily extended to a large extent. Examples of long-chain polyols include polyester polyols such as lactone-based polyester polyols and adipate-based polyester polyols; polypropylene (ethylene) polyols and polytetramethylene ether glycols Such as polyether polyol; polycarbonate polyol, etc. In this embodiment, the long-chain polyol is preferably an adipate-based polyester polyol from the viewpoint of being easy to extend to a large extent.

Examples of diisocyanates include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, and the like. In this embodiment, the diisocyanate is preferably hexamethylene diisocyanate from the viewpoint of ease of large extension. Examples of chain extenders include low molecular weight polyols (for example, 1,4-butanediol, 1,6-hexanediol, etc.), aromatic diamines, and the like. Among these, 1,6-hexanediol is preferably used from the viewpoint of ease of large extension. Examples of olefin-based elastomers include those selected from ethylene·α-olefin copolymers, propylene·α-olefin copolymers, butene·α-olefin copolymers, ethylene·propylene·α-olefin copolymers, ethylene·butene· α-olefin copolymer, propylene, butene, α-olefin copolymer, ethylene, propylene, butene, α-olefin copolymer, styrene, isoprene copolymer, and styrene, ethylene, butene copolymer A group of at least one resin elastomer. An olefin-based elastomer may be used alone or in combination of two or more kinds.

The density of the olefin-based elastomer is not particularly limited. For example the density of the olefin-based elastomer is preferably 0.860g / cm ³ or more and less than 0.905g / cm ^3, more preferably 0.862g / cm ³ or more and less than 0.900g / cm ^3, particularly preferably 0.864g / cm ^{3 and} above, less than 0.895g/cm ³ . When the density of the olefin-based elastomer satisfies the above-mentioned range, the substrate has excellent unevenness followability when attaching a semiconductor device such as a semiconductor wafer as an adherend to an adhesive sheet. Among all the monomers used to form the olefin-based elastomer, the mass ratio of monomers made of olefin-based compounds (also referred to as "olefin content" in this specification) is preferably 50% by mass or more. 100 Less than mass%. When the olefin content is too low, it is difficult to express the properties of an elastomer containing structural units derived from olefins, and it is difficult for the substrate to exhibit flexibility and rubber elasticity. From the viewpoint of stably obtaining flexibility and rubber elasticity, the olefin content is preferably 50% by mass or more, and more preferably 60% by mass or more.

Examples of the styrene-based elastomer include styrene-conjugated diene copolymers, styrene-olefin copolymers, and the like. As specific examples of styrene-conjugated diene copolymers, styrene-butadiene copolymers, styrene-butadiene-styrene copolymers (SBS), styrene-butadiene-butene copolymers can be exemplified -Unhydrogenated styrene copolymer, styrene-isoprene copolymer, styrene-isoprene-styrene copolymer (SIS), styrene-ethylene-isoprene-styrene copolymer, etc. Styrene-conjugated diene copolymer, styrene-ethylene/propylene-styrene copolymer (SEPS, hydrogenated product of styrene-isoprene-styrene copolymer) and styrene-ethylene-butene-benzene Hydrogenated styrene-conjugated diene copolymers such as ethylene copolymers (SEBS, hydrogenated styrene-butadiene copolymers). In addition, industrially, as styrene elastomers, examples include Tufprene (manufactured by Asahi Kasei Co., Ltd.), Clayton (manufactured by Clayton Polymer Co., Ltd.), Sumitomo TPE-SB (manufactured by Sumitomo Chemical Co., Ltd.), and Epofriend (Made by DAICEL Co., Ltd.), Rabaron (made by Mitsubishi Chemical Co., Ltd.), Septon (made by Kuraray Co., Ltd.), Tuftec (made by Asahi Kasei Co., Ltd.), etc. The styrene elastomer may be a hydrogenated product or an unhydrogenated product.

Examples of rubber-based materials include natural rubber, synthetic isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), acrylonitrile -Butadiene copolymer rubber (NBR), butyl rubber (IIR), halogenated butyl rubber, acrylic rubber, urethane rubber and polyvulcanized rubber, etc. The rubber-based materials may be used alone or in combination of two or more. The second substrate 21 is not a laminate film formed by laminating multiple films made of the above-mentioned materials (for example, thermoplastic elastomer or rubber-based materials), but is preferably a single-layer film. In addition, the second substrate 21 is not a laminated film formed by laminating a film made of the above-mentioned material (for example, a thermoplastic elastomer or a rubber-based material) with another film, but is preferably a single-layer film. The second base material 21 may contain an additive in a film mainly made of the above-mentioned resin-based material. Specific examples of the additives are the same as those described and exemplified for the first base material 11. Examples of additives include pigments, dyes, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. As the pigment, for example, titanium dioxide and carbon black are exemplified. In addition, examples of fillers include organic materials such as melamine resin, inorganic materials such as fumed silica, and metal materials such as nickel particles. The content of additives that can be contained in the film is not particularly limited, but is preferably limited to a range where the second base material 21 can exhibit desired functions.

The second base material 21 is the same as the first base material 11, and can also be implemented on one or both sides of the second base material 21 to increase the density with the second adhesive layer 22 laminated on the surface of the second base material 21. Intensive treatment. When the second adhesive layer 22 contains an energy ray curable adhesive, the second base material 21 preferably has energy ray permeability. When ultraviolet rays are used as energy rays, the second base material 21 is preferably transparent to ultraviolet rays. When an electron beam is used as the energy beam, the second base material 21 preferably has electron beam permeability. The thickness of the second base material 21 is not particularly limited as long as the second sheet 20 can appropriately function in a desired step. The thickness of the second substrate 21 is preferably 20 μm or more, more preferably 40 μm or more. In addition, the thickness of the second substrate 21 is preferably 250 μm or less, and more preferably 200 μm or less.

In addition, the standard deviation of the thickness of the second base material 21 when measuring the thickness of a plurality of parts at 2 cm intervals in the in-plane direction of the first base material surface or the second base material surface of the second base material 21 is preferably 2 μm or less, and more It is preferably 1.5 μm or less, and more preferably 1 μm or less. With the standard deviation of 2 μm or less, the second sheet 20 has a highly accurate thickness, and the second sheet 20 can be stretched uniformly. The tensile modulus of elasticity in the MD and CD directions of the second substrate 21 at 23°C is 10 MPa or more and 350 MPa or less. The 100% stress in the MD and CD directions of the second substrate 21 at 23° C. Preferably, they are 3 MPa or more and 20 MPa or less. By setting the tensile modulus of elasticity and 100% stress within the above-mentioned ranges, the second sheet 20 can be greatly extended.

The 100% stress of the second substrate 21 is a value obtained as follows. A test piece with a size of 150 mm (length direction)×15 mm (width direction) was cut out from the second base material 21. The both ends of the cut test piece in the longitudinal direction were pinched by the pinch clamps so that the length between the pinch clamps became 100 mm. After the test piece was pinched with the pinch jig, it was stretched in the length direction at a speed of 200 mm/min, and the measured value of the tensile force when the length between the pinch jigs reached 200 mm was read. The 100% stress of the second substrate 21 is a value obtained by dividing the read tensile force measurement value by the cross-sectional area of the substrate. The cross-sectional area of the second base material 21 was calculated as 15 mm in the width direction×the thickness of the second base material 21 (test piece). This cutting is performed in such a way that the traveling direction (MD direction) or the direction orthogonal to the MD direction (CD direction) at the time of the base material production coincides with the length direction of the test piece. In addition, in this tensile test, the thickness of the test piece is not particularly limited, and may be the same as the thickness of the substrate to be tested. The elongation at break of the second substrate 21 in the MD direction and the CD direction at 23° C. is preferably 100% or more. By setting the elongation at break of the second base material 21 in the MD direction and the CD direction to 100% or more, the second sheet 20 can be extended significantly without breaking.

The tensile elastic modulus (MPa) of the substrate and the elongation at break (%) of the substrate can be measured as follows. The base material was cut into 15 mm×140 mm to obtain a test piece. For this test piece, the elongation at break and the tensile modulus of elasticity at 23° C. were measured in accordance with JIS K7161:2014 and JIS K7127:1999. Specifically, the above-mentioned test piece was tested with a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph AG-IS 500N") at a distance of 100 mm between clamps, and a tensile test was performed at a speed of 200 mm/min. , Determine the elongation at break (%) and tensile modulus (MPa). In addition, the measurement was performed in both the direction of travel (MD) and the direction (CD) at right angles to the substrate at the time of manufacture.

・Second adhesive layer The material of the second adhesive layer 22 is not particularly limited as long as it can exhibit an appropriate function in a desired step such as an expansion step. Examples of the adhesive contained in the second adhesive layer 22 are, for example, a rubber-based adhesive, an acrylic adhesive, a silicone-based adhesive, a polyester-based adhesive, and a urethane-based adhesive.

・Energy ray curable resin (ax1) The second adhesive layer 22 preferably contains an energy ray curable resin (ax1). The energy ray curable resin (ax1) has an energy ray curable double bond in the molecule. The adhesive layer containing energy ray curable resin is cured by energy ray irradiation and reduces the adhesive force. To separate the adherend and the adhesive sheet, the adhesive layer can be easily separated by irradiating energy rays. The energy ray curable resin (ax1) is preferably a (meth)acrylic resin. The energy ray curable resin (ax1) is preferably an ultraviolet curable resin, more preferably an ultraviolet curable (meth)acrylic resin. Energy ray curable resin (ax1) is a resin that polymerizes and hardens when irradiated with energy rays. Examples of energy rays include ultraviolet rays and electron beams. As an example of the energy-ray curable resin (ax1), low-molecular-weight compounds (monofunctional monomers, multifunctional monomers, monofunctional oligomers, and multifunctional oligomers) having energy ray polymerizable groups are exemplified. The energy ray curable resin (ax1) specifically uses trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxy pentaacrylate, and dipentaerythritol hexaacrylate , 1,4-butanediol diacrylate and 1,6-hexanediol diacrylate and other acrylates, dicyclopentadiene dimethoxy diacrylate and isobornyl acrylate, etc. containing ring Acrylic esters with morphological aliphatic skeleton, as well as polyethylene glycol diacrylate, oligopolyester acrylate, urethane acrylate oligomer, epoxy modified acrylate, polyether acrylate and itaconic acid oligomer Acrylate compounds such as polymers. The energy ray curable resin (a1) can be used alone or in combination of two or more kinds. The molecular weight of the energy ray curable resin (ax1) is usually 100 or more and 30,000 or less, preferably 300 or more and 10,000 or less.

・(Meth)acrylic copolymer (b1) The second adhesive layer 22 preferably further contains a (meth)acrylic copolymer (b1). The (meth)acrylic copolymer is different from the aforementioned energy ray curable resin (ax1). The (meth)acrylic copolymer (b1) preferably has an energy-ray curable carbon-carbon double bond. That is, in this embodiment, the second adhesive layer 22 preferably contains an energy ray curable resin (ax1) and an energy ray curable (meth)acrylic copolymer (b1). The second adhesive layer 22 is preferably in a ratio of 10 parts by mass or more to 100 parts by mass of the (meth)acrylic copolymer (b1), more preferably in a ratio of 20 parts by mass or more, and still more preferably in a ratio of 25 parts by mass or more The ratio contains energy ray curable resin (ax1). The second adhesive layer 22 is preferably at a ratio of 80 parts by mass or less to 100 parts by mass of the (meth)acrylic copolymer (b1), more preferably at a ratio of 70 parts by mass or less, and still more preferably at a ratio of 60 parts by mass or less The ratio contains energy ray curable resin (ax1).

The weight average molecular weight (Mw) of the (meth)acrylic copolymer (b1) is preferably 10,000 or more, more preferably 150,000 or more, and still more preferably 200,000 or more. In addition, the weight average molecular weight (Mw) of the (meth)acrylic copolymer (b1) is preferably 1.5 million or less, more preferably 1 million or less. In addition, the weight average molecular weight (Mw) in this specification is a value in terms of standard polystyrene measured by gel permeation chromatography (GPC method). The (meth)acrylic copolymer (b1) is preferably a (meth)acrylate copolymer (b2) in which a functional group having energy ray curability (energy ray curable group) is introduced into the side chain (hereinafter sometimes It is called "energy-ray curable polymer (b2)").

・Energy ray curable polymer (b2) The energy-ray curable polymer (b2) is preferably an acrylic copolymer (b21) having a functional group-containing monomer unit and an unsaturated group-containing compound (b22) having a functional group bonded to the functional group And the resulting copolymer. In this specification, (meth)acrylate means both acrylate and methacrylate. Other similar terms are also the same. The acrylic copolymer (b21) preferably contains a structural unit derived from a functional group-containing monomer and a structural unit derived from a (meth)acrylate monomer or a derivative of a (meth)acrylate monomer. The functional group-containing monomer as a structural unit of the acrylic copolymer (b21) is preferably a monomer having a polymerizable double bond and a functional group in the molecule. The functional group is preferably at least any functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group.

Examples of hydroxyl-containing monomers include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxy (meth)acrylate Butyl ester, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc. The hydroxyl-containing monomer can be used alone or in combination of two or more. Examples of carboxyl group-containing monomers include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. The carboxyl group-containing monomer can be used individually by 1 type or in combination of 2 or more types. Examples of the amine group-containing monomer or the substituted amine group-containing monomer are, for example, aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate. The amine group-containing monomer or the substituted amine group-containing monomer can be used alone or in combination of two or more.

As the (meth)acrylate monomer constituting the acrylic copolymer (b21), in addition to the alkyl (meth)acrylate having an alkyl group of 1 to 20 carbon atoms, it is preferable to use an alicyclic structure in the molecule The monomer (monomer with alicyclic structure). The alkyl (meth)acrylate is preferably an alkyl (meth)acrylate having an alkyl group with a carbon number of 1 or more and 18 or less. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and (meth)acrylic acid 2 -Ethylhexyl ester. As the alkyl (meth)acrylate, one type can be used alone or two or more types can be used in combination. As the monomer containing an alicyclic structure, for example, cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, Dicyclopentenyl (meth)acrylate and dicyclopentenoxyethyl (meth)acrylate, etc. The alicyclic structure-containing monomer can be used alone or in combination of two or more.

The acrylic copolymer (b21) preferably contains the constituent units derived from the functional group-containing monomer in a proportion of 1% by mass or more, more preferably in a proportion of 5% by mass or more, and still more preferably in a proportion of 10% by mass or more contain. In addition, the acrylic copolymer (b21) preferably contains the constituent units derived from the functional group-containing monomer in a proportion of 35% by mass or less, more preferably in a proportion of 30% by mass or less, and more preferably 25% by mass or less The ratio contains. Furthermore, the acrylic copolymer (b21) preferably contains the constituent units derived from the (meth)acrylate monomer or its derivative in a proportion of 50% by mass or more, more preferably in a proportion of 60% by mass or more, and More preferably, it is contained in a ratio of 70% by mass or more. Furthermore, the acrylic copolymer (b21) preferably contains the constituent units derived from the (meth)acrylate monomer or its derivative in a proportion of 99% by mass or less, more preferably in a proportion of 95% by mass or less, and more It is preferably contained in a proportion of 90% by mass or less.

The acrylic copolymer (b21) is obtained by copolymerizing the above-mentioned functional group-containing monomer and (meth)acrylate monomer or its derivative by a common method. The acrylic copolymer (b21) may contain at least any structural unit selected from the group consisting of dimethylacrylamide, vinyl formate, vinyl acetate, and styrene in addition to the above-mentioned monomers. The acrylic copolymer (b21) having the aforementioned functional group-containing monomer unit is reacted with an unsaturated group-containing compound (b22) having a functional group bonded to the functional group to obtain an energy-ray curable polymer (b2). The functional group of the unsaturated group-containing compound (b22) can be appropriately selected corresponding to the functional group type of the functional group-containing monomer unit of the acrylic copolymer (b21). For example, when the functional group of the acrylic copolymer (b21) is a hydroxyl group, an amino group or a substituted amino group, the functional group of the unsaturated group-containing compound (b22) is preferably an isocyanate group or an epoxy group. When the functional group possessed by the copolymer (b21) is an epoxy group, the functional group possessed by the unsaturated group-containing compound (b22) is preferably an amino group, a carboxyl group or an aziridin group.

The unsaturated group-containing compound (b22) contains at least one in one molecule, preferably one to six and more preferably one to four energy ray polymerizable carbon-carbon double bonds. Examples of the unsaturated group-containing compound (b22) are, for example, 2-methacryloxyethyl isocyanate (2-isocyanatoethyl methacrylate), m-isocyanate-isopropenyl-α,α -Dimethyl benzyl, methacrylic isocyanate, allyl isocyanate, 1,1-(bisacryloxymethyl) ethyl isocyanate; diisocyanate compound or polyisocyanate compound and Acrylic monoisocyanate compound obtained by reacting hydroxyethyl (meth)acrylate; Acrylic monoisocyanate compound obtained by reacting diisocyanate compound or polyisocyanate compound with polyol compound and hydroxyethyl (meth)acrylate; Glycidyl (meth)acrylate; (meth)acrylic acid, 2-(1-aziridinyl)ethyl (meth)acrylate, 2-vinyl-2-oxazoline, 2-isopropenyl- 2-oxazoline and so on.

The unsaturated group-containing compound (b22) is preferably used at a ratio (addition rate) of 50 mol% or more relative to the molar number of the functional group-containing monomer of the acrylic copolymer (b21), and more preferably 60 mol% It is used in the proportion of ear% or more, and preferably in the proportion of 70 mol% or more. And the unsaturated group-containing compound (b22) is preferably used in a ratio of 95 mol% or less relative to the mol number of the functional group-containing monomer of the acrylic copolymer (b21), more preferably 93 mol% or less It is used in proportion, and it is better to use in a proportion of less than 90 mol%. The reaction between the acrylic copolymer (b21) and the unsaturated group-containing compound (b22) can correspond to the functional group of the acrylic copolymer (b21) and the functional group of the unsaturated group-containing compound (b22) Combination, appropriate selection of reaction temperature, pressure, solvent, time, presence or absence of catalyst and type of catalyst. Thereby, the functional group of the acrylic copolymer (b21) is reacted with the functional group of the unsaturated group-containing compound (b22) to introduce the unsaturated group into the side chain of the acrylic copolymer (b21) to obtain energy rays Curing polymer (b2). The weight average molecular weight (Mw) of the energy ray curable polymer (b2) is preferably 10,000 or more, more preferably 150,000 or more, and still more preferably 200,000 or more. In addition, the weight average molecular weight (Mw) of the energy ray curable polymer (b2) is preferably 1.5 million or less, more preferably 1 million or less.

・Photopolymerization initiator (CX) When the second adhesive layer 22 contains an ultraviolet curable compound (for example, an ultraviolet curable resin), the second adhesive layer 22 preferably contains a photopolymerization initiator (CX). By making the second adhesive layer 22 contain a photopolymerization initiator (CX), the polymerization curing time and the amount of light irradiation can be reduced. The specific example of the photopolymerization initiator (CX) is the same as the polymer example of the photopolymerization initiator (G) in the description of the first adhesive sheet 10. In the second sheet 20, the photopolymerization initiator (CX) may be used alone or in combination of two or more kinds.

When the energy-ray curable resin (ax1) and (meth)acrylic copolymer (b1) are blended in the adhesive layer, the photopolymerization initiator (CX) is relative to the energy-ray curable resin (ax1) and (methyl) ) The total amount of the acrylic copolymer (b1) is 100 parts by mass, preferably 0.1 parts by mass or more, and more preferably 0.5 parts by mass or more. In addition, when the energy ray curable resin (ax1) and the (meth)acrylic copolymer (b1) are blended in the adhesive layer, the photopolymerization initiator (CX) is relative to the energy ray curable resin (ax1) and ( The total amount of the meth)acrylic copolymer (b1) is 100 parts by mass, preferably 10 parts by mass or less, and more preferably 6 parts by mass or less. In addition to the above-mentioned components, the second adhesive layer 22 may be blended with other suitable components. Examples of other components include, for example, a crosslinking agent (EX).

・Crosslinking agent (EX) As the crosslinking agent (EX), a compound having reactivity with the functional group of the (meth)acrylic copolymer (b1) or the like can be used. Examples of polyfunctional compounds in the second sheet 20 include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, and metal alkoxide compounds. , Metal chelating compounds, metal salts, ammonium salts and reactive phenol resins, etc. The compounding amount of the crosslinking agent (EX) is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, and still more preferably 0.04 parts by mass relative to 100 parts by mass of the (meth)acrylic copolymer (b1) the above. In addition, the blending amount of the crosslinking agent (E) is preferably 8 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 3.5 parts by mass relative to 100 parts by mass of the (meth)acrylic copolymer (b1) Parts by mass or less.

The thickness of the second adhesive layer 22 is not particularly limited. The thickness of the second adhesive layer 22 is, for example, preferably 10 μm or more, and more preferably 20 μm or more. In addition, the thickness of the second adhesive layer 22 is preferably 150 μm or less, and more preferably 100 μm or less, for example. The recovery rate of the second sheet 20 is preferably 70% or more, more preferably 80% or more, and still more preferably 85% or more. The recovery rate of the second sheet 20 is preferably 100% or less. If the recovery rate is in the above range, the adhesive sheet can be extended significantly. The recovery rate is to cut a 150mm (length direction) x 15mm (width direction) test piece from the adhesive sheet, pinch both ends of the length direction by the pinch jigs so that the length between the pinch jigs becomes 100mm, and then place the pinch between the jigs. The length is stretched at a speed of 200mm/min to become 200mm, and the length between the pinch clamps is expanded to 200mm for 1 minute, and then the length between the pinch clamps is restored to the length between the pinch clamps at a speed of 200mm/min. When the length becomes 100mm, hold for 1 minute with the length between the pinch clamps returning to 100mm, then stretch in the length direction at a speed of 60mm/min, and measure the tensile force between the pinch clamps when the measured value shows 0.1N/15mm Length, the length minus the initial length between the pinch clamps 100mm is L2(mm), and the length between the initial pinch clamps is 200mm minus the initial length between the pinch clamps 100mm. When it is set to L1 (mm), it is calculated by the following mathematical formula (Equation 2). Recovery rate (%)={1-(L2÷L1)}×100・・・(Number 2)

When the recovery rate is in the above range, it means that it is easy to recover even if the adhesive sheet is greatly extended. Generally, if a sheet with a yield point extends above the yield point, the sheet causes plastic deformation, and the part that causes plastic deformation, that is, the extremely extended part becomes a local state. If the sheet in these states is further extended, it will break from the extreme extended part, or even if it does not break, the expansion will be uneven. In addition, in the stress-deformation diagram with deformation as the x-axis and elongation as the y-axis, even if the slope dx/dy does not become a stress value that changes from a positive value to 0 or a negative value, and does not Sheets showing a clear yield point will also cause plastic deformation as the amount of stretch becomes larger, and will also break or expand unevenly. On the other hand, in the case of elastic deformation without plastic deformation, the sheet is easily restored to its original shape by removing the stress. Therefore, by setting the recovery rate, which is an index indicating the degree of recovery after 100% elongation with a sufficiently large amount of stretching, to the above range, the plastic deformation of the film can be suppressed to a minimum when the adhesive sheet is greatly stretched. , And it is difficult to break, and can expand uniformly.

・Peeling sheet For the purpose of protecting the adhesive surface of the second sheet 20 until its adhesive surface is attached to the adherend (such as a semiconductor chip, etc.), a release sheet may be laminated on the adhesive surface. The structure of the peeling sheet is arbitrary, and the peeling process of a plastic film with a peeling agent etc. is illustrated. The release sheet may be a release sheet that can be used for the first adhesive sheet 10. The thickness of the second sheet 20 is preferably 30 μm or more, more preferably 50 μm or more. The thickness of the second sheet 20 is preferably 400 μm or less, more preferably 300 μm or less.

[Effects of this embodiment] According to the expansion method of this embodiment, when the second sheet 20 is stretched, the back surface W3 of the semiconductor chip CP does not contact the second adhesive layer 22 of the second sheet 20. In each of the semiconductor chips CP, since the back surface W3 and the second adhesive layer 22 are interposed between the first adhesive layer 12 of the first adhesive sheet 10 singulated in the dicing step, even if the second adhesive layer is stretched The sheet 20 and the first adhesive layer 12 in contact with the back surface W3 are also not elongated. As a result, according to the expansion method of this embodiment, residual blur can be suppressed. In addition, in this embodiment, during the dicing step, the semiconductor wafer W is not supported by the dicing sheet, but is supported by the first adhesive sheet 10. Therefore, in order to form a layer (the first adhesive layer 12 in this embodiment) for protecting the back W3 of the semiconductor chip CP after dicing, it is not necessary to replace the adhesive sheet used in the dicing step with another adhesive sheet. In the step, if peeling between the first substrate 11 and the first adhesive layer 12, a layer for protecting the back surface W3 can be formed. Furthermore, before implementing the expansion step, in order to change the adhesive sheet used during the cutting step to the adhesive sheet for the expansion step, it is not necessary to carefully control the cutting depth so that the cutting blade will not reach the cutting during the cutting step. The substrate of the sheet. Therefore, according to the extended method of the present embodiment, the tape structure and the manufacturing process can be simplified and the residual sticking can be suppressed compared with the prior art. Furthermore, it is possible to provide a method of manufacturing a semiconductor device including the extension method of this embodiment.

[Second Embodiment] Next, the second embodiment of the present invention will be described. The first embodiment and the second embodiment are mainly different in the following points. The second sheet 20 used in the expansion step in the first embodiment has a laminated structure of the second base material 21 and the second adhesive layer 22. In contrast, in the second embodiment, the second sheet used in the expansion step The two sheets 20A have a single-layer structure composed of the second substrate 21A. In the following description, differences from the first embodiment are mainly described, and repeated descriptions are omitted or simplified. The same components as those in the first embodiment are given the same reference numerals, and the description is omitted or simplified.

Fig. 5 shows a diagram for explaining the "sticking step of the second sheet" of the second embodiment. In this embodiment, after the "peeling step of the first base material", as shown in FIG. 5, the second sheet 20A is adhered on the first adhesive layer 12 adhered to the back surface W3 of the semiconductor chip CP. The second sheet 20A of this embodiment has a single-layer structure composed of the second substrate 21A as described above. Unlike the second sheet 20, the second sheet 20A does not have an adhesive layer, etc., but since the first adhesive layer 12 is adhesive, the semiconductor chip CP can be supported on the second substrate via the first adhesive layer 12 On 21A. As a specific example of the second substrate 21A, the same substrate as the second substrate 21 described in the first embodiment can be used. Fig. 6 shows a diagram for explaining the "expansion procedure" of the second embodiment. As shown in FIG. 6, the plurality of semiconductor chips CP supported on the second sheet 20A via the first adhesive layer 12 expands the distance between each other by expanding the second sheet 20A. Due to the expansion, in the thickness direction of the first adhesive layer 12, the second substrate 21A side of the first adhesive layer 12 is stretched preferentially, so it is difficult for the first adhesive layer 12 on the back side W3 of the semiconductor chip CP to be stretched. Deformed. Regarding the extension method of the second embodiment and the method of manufacturing a semiconductor device including the extension method, other aspects can be implemented in the same manner as the first embodiment.

[Effects of this embodiment] According to the expansion method of the present embodiment, as in the first embodiment, the tape structure and manufacturing process can be simplified compared with the prior art, and residual sticking can be suppressed. Furthermore, it is possible to provide a method of manufacturing a semiconductor device including the extension method of this embodiment. In addition, according to the present embodiment, the expanded sheet is not an adhesive sheet composed of an adhesive layer and a base material layer, but a second sheet 20A of a single-layer structure formed of the second base material 21A with a simpler structure. The distance between the plurality of semiconductor chips CP can be expanded.

[Third Embodiment] Next, the third embodiment of the present invention will be described. The first embodiment and the third embodiment are mainly different in the following points. In the first embodiment, the semiconductor wafer W is attached to the first adhesive sheet 10 having the first base material 11 and the first adhesive layer 12. In contrast, in the third embodiment, the first base material 11 and the first adhesive sheet 10 1 The semiconductor wafer W is pasted on the first adhesive sheet 10A including the intermediate adhesive layer 13 between the adhesive layers 12. In the following description, differences from the first embodiment are mainly described, and repeated descriptions are omitted or simplified. The same components as those in the first embodiment are given the same reference numerals, and the description is omitted or simplified.

FIG. 7A is a diagram for explaining the step (P1) of the third embodiment (the step of preparing the wafer W for pasting the first adhesive sheet 10A on the back surface W3). FIG. 7A shows the wafer W to which the first adhesive sheet 10A is attached. The first adhesive sheet 10A has a first base material 11, a first adhesive layer 12 and an intermediate adhesive layer 13. The first adhesive sheet 10A includes an intermediate adhesive layer 13 between the first base material 11 and the first adhesive layer 12. The first base material 11 of the first adhesive sheet 10A uses the same base material as the first base material described in the first embodiment. The first adhesive layer 12 of the first adhesive sheet 10A uses the same adhesive layer as the first adhesive layer 12 described in the first embodiment. The first adhesive layer 12 of this embodiment preferably contains a curable adhesive adhesive composition that is cured by receiving energy from the outside. In the first adhesive sheet 10A, the first adhesive layer 12 is laminated on the intermediate adhesive layer 13 provided on the first substrate 11.

The intermediate adhesive layer 13 may be formed of a weakly adhesive adhesive having an adhesive force that can be peeled off from the first adhesive layer 12, or may be formed of an energy-ray curable adhesive whose adhesive force is reduced by irradiation with energy rays . In addition, when an adhesive layer formed of an energy-ray curable adhesive is used as the intermediate adhesive layer 13, the area where the first adhesive layer 12 is laminated (for example, the inner peripheral portion of the first base material 11) is previously energy Ray irradiation reduces the adhesion in advance. On the other hand, other areas (such as the outer periphery of the first substrate 11) are not irradiated with energy rays. For example, for the purpose of sticking to a jig, the adhesion can be maintained at a relatively high level. high. In order not to perform energy ray irradiation only in other regions, an energy ray shielding layer may be provided in regions corresponding to other regions of the first substrate 11 by printing, and energy ray irradiation may be performed from the first substrate 11 side. The intermediate adhesive layer 13 can be formed by various conventional adhesives. The intermediate adhesive layer 13 may be formed by at least any adhesive selected from the group of widely used adhesives, energy-ray hardening adhesives, and adhesives containing thermal expansion components. The widely used adhesive is preferably at least any selected from the group consisting of, for example, rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, and vinyl ether-based adhesives. An adhesive. In addition, the form of the intermediate adhesive layer 13 also includes a form having a core material and an adhesive layer provided on both sides of the core material.

In addition, the intermediate adhesive layer 13 is also preferably a thermally expandable adhesive layer. The heat-expandable adhesive layer is formed with a heat-expandable adhesive. The heat-expandable adhesive contains an adhesive and a heat-expandable component. When the intermediate adhesive layer 13 is a heat-expandable adhesive layer, the contact area between the heat-expandable adhesive layer and the adherend is reduced by heating, and the adhesive force can be reduced. As the thermally expandable component, thermally expandable fine particles can be used. The thermally expandable fine particles are, for example, fine particles in which a substance that is easily vaporized and expanded by heating is enclosed in an elastic shell. Examples of substances to be gasified and expanded include isobutane, propane, and pentane. In particular, the heat-expandable fine particles are preferable because the surface shape of the adhesive layer can be easily controlled after being heated and expanded, so that the state of the adhesive layer can be easily self-strengthened and easily peeled by heating. Moreover, a foaming agent can also be used as a thermally expandable component. The blowing agent is, for example, a chemical substance that has the ability to generate gas through thermal decomposition. Examples of the generated gas include water, carbon dioxide, and nitrogen. By dispersing the foaming agent in the adhesive, the effect is similar to that of thermally expandable particles. The thickness of the intermediate adhesive layer 13 is not particularly limited. The thickness of the intermediate adhesive layer 13 is usually 1 μm or more and 50 μm or less, preferably 5 μm or more and 30 μm or less.

[Cutting step] Fig. 7B is a diagram for explaining the cutting step of this embodiment. FIG. 7B shows a plurality of semiconductor chips CP held by the first adhesive sheet 10A. The semiconductor wafer W in the state where the first adhesive sheet 10A is attached to the back surface W3 is diced and singulated to form a plurality of semiconductor chips CP. In this embodiment, a cut is made from the circuit surface W1 side to cut the semiconductor wafer W, and further cut at least the first adhesive layer 12 of the first adhesive sheet 10A. The first adhesive layer 12 is also cut to the same size as the semiconductor wafer CP. The cutting system uses a cutting mechanism such as a cutting saw. The cutting depth at the time of dicing is not particularly limited as long as it is a depth at which the semiconductor wafer W and the first adhesive layer 12 can be singulated. In this embodiment, a state where the cut does not reach the intermediate adhesive layer 13 and the first base material 11 is taken as an example for description, but the present invention is not limited to these aspects. For example, in other aspects, based on the viewpoint of surely cutting the semiconductor wafer W and the first adhesive layer 12, by dicing, it is also possible to form a cut to the depth of the intermediate adhesive layer 13, or to reach the first base. Material 11 depth of incision. In addition, in the dicing step of the present embodiment, the dicing is performed along the end surface of the semiconductor wafer W, and a slit is formed in the first adhesive layer 12 as shown in FIG. 7B.

[Peeling step of the first base material and the intermediate adhesive layer] Fig. 7C is a diagram for explaining the step (P3) of this embodiment. In this embodiment, after the cutting step, the first base material 11 and the intermediate adhesive layer 13 are peeled from the first adhesive layer 12. This step is sometimes referred to as the peeling step of the first base material and the intermediate adhesive layer. FIG. 7C shows the step of peeling the first base material 11 and the intermediate adhesive layer 13 in a state where the first adhesive layer 12 remains on the back surface W3 of the singulated semiconductor chip CP after dicing. In the peeling step, peeling is performed at the interface between the first adhesive layer 12 and the intermediate adhesive layer 13. When the first base material 11 and the intermediate adhesive layer 13 are peeled off, a plurality of semiconductor wafers CP with the first adhesive layer 12 attached to the back surface W3 is obtained. Furthermore, in the peeling step of the first base material of this embodiment, the first adhesive layer 12 that is not attached to the back surface W3 of the semiconductor chip CP is removed in a state of being attached to the intermediate adhesive layer 13 as shown in FIG. 7C.

The peeling force when peeling the first base material 11 and the intermediate adhesive layer 13 from the first adhesive layer 12 is preferably 50 mN/25 mm or more and 2000 mN/25 mm or less. By setting the peeling force when peeling the first base material 11 and the intermediate adhesive layer 13 from the first adhesive layer 12 to 50 mN/25 mm or more, the effect of excellent wafer retention during dicing is obtained. By setting the peeling force when peeling the first base material 11 and the intermediate adhesive layer 13 from the first adhesive layer 12 to 2000 mN/25 mm or less, an effect of excellent peelability is obtained. The peeling force when peeling the first base material 11 and the intermediate adhesive layer 13 from the first adhesive layer 12 is more preferably 50 mN/25 mm or more and 2000 mN/25 mm or less, and still more preferably 100 mN/25 mm or more and 1500 mN/25 mm or less. In this embodiment, similar to the peeling force when peeling off the first base material 11 from the first adhesive layer 12, stretching is performed to peel off the first base material 11 and the intermediate adhesive layer 13 from the first adhesive layer 12 In the test, the load measured during the tensile test is taken as the peel force. Regarding the extension method of the third embodiment and the method of manufacturing a semiconductor device including the extension method, other aspects can be implemented in the same manner as the first embodiment. [Effects of this embodiment] According to the expansion method of this embodiment, similar to the first embodiment, the tape structure and manufacturing process can be simplified and residual sticking can be suppressed compared with the prior art. Furthermore, according to the expansion method of this embodiment, the deformation of the first adhesive layer 12 can be suppressed compared with the second embodiment. Furthermore, it is possible to provide a method of manufacturing a semiconductor device including the extension method of this embodiment.

[Fourth Embodiment] Next, the fourth embodiment of the present invention will be described. The first embodiment and the fourth embodiment are mainly different in the following points. In the fourth embodiment, before the step of peeling off the first base material 11 (step (P3)) and after the dicing step, the fourth adhesive sheet 40 as a holding member is stuck on the circuit surface W1 of the plurality of semiconductor chips CP. The holding member is not limited to the adhesive sheet, as long as it is a member (for example, a suction holding table, etc.) that can hold a plurality of semiconductor wafers CP when the first base material 11 is peeled off. In the following description, differences from the first embodiment are mainly described, and repeated descriptions are omitted or simplified. The same components as those in the first embodiment are given the same reference numerals, and the description is omitted or simplified.

[The 4th adhesive sheet pasting step] FIG. 8A shows a diagram for explaining the step of pasting the fourth adhesive sheet 40 on the circuit surface W1 of the plurality of semiconductor chips CP after the cutting step (step (P2)). This step is sometimes called the fourth adhesive sheet pasting step. The fourth adhesive sheet 40 has a fourth base material 41 and a fourth adhesive layer 42. The material of the fourth substrate 41 is not particularly limited. Examples of the material of the fourth substrate 41 include, for example, polyvinyl chloride resin, polyester resin (polyethylene terephthalate, etc.), acrylic resin, polycarbonate resin, polyethylene resin, polypropylene resin, acrylonitrile, etc. Butadiene, styrene resin, polyimide resin, polyurethane resin, polystyrene resin, etc. The adhesive contained in the fourth adhesive layer 42 is not particularly limited. Examples of the adhesive contained in the fourth adhesive layer 42 include rubber-based, acrylic-based, silicone-based, polyester-based, and urethane-based adhesives. In addition, the type of adhesive is selected in consideration of the use and the type of the adherend to be adhered. The fourth adhesive sheet 40 may be adhered to the second ring frame together with the plurality of semiconductor chips CP. In this case, the second ring-shaped frame is placed on the fourth adhesive layer 42 of the fourth adhesive sheet 40, and it is gently pressed and fixed. Subsequently, the fourth adhesive layer 42 exposed inside the ring shape of the second ring frame is pressed against the circuit surface W1 of the semiconductor chip CP to fix the plurality of semiconductor chips CP to the fourth adhesive sheet 40.

[Peeling step of the first substrate] 8B is a diagram illustrating the step of peeling off the first base material 11 of the first adhesive sheet 10 after the fourth adhesive sheet 40 is attached. In this embodiment, the first adhesive layer 12 is left on the back surface W3 of the semiconductor wafer CP, and the first base material 11 is peeled off. As one aspect of the first adhesive sheet 10, when the first adhesive layer 12 is directly laminated on the first substrate 11, in the peeling step of the first substrate, the first adhesive layer 12 is preferred The interface with the first substrate 11 peels off. When the first base material 11 is peeled off, a plurality of semiconductor wafers CP having the first adhesive layer 12 attached to the back surface W3 is obtained. Moreover, in the peeling step of the first substrate of this embodiment, the first adhesive layer 12 that is not attached to the back surface W3 of the semiconductor chip CP is removed in a state of being attached to the first substrate 11 as shown in FIG. 8B.

[Paste the second sheet] Fig. 8C is a diagram for explaining the step (P4). FIG. 8C shows the state where the second sheet 20 is pasted on the plurality of semiconductor chips CP obtained by the dicing step. The second sheet 20 of this embodiment can use the same sheet as the second sheet 20 described in the first embodiment. In one aspect of the present invention, instead of the second sheet 20 of this embodiment, the same sheet as the second sheet 20A described in the second embodiment may be used. In the present embodiment, when the second sheet 20 is adhered to the back W3 side of the plurality of semiconductor chips CP, a singulated first adhesive is obtained between the plurality of semiconductor chips CP and the second adhesive layer 22 of the second sheet 20. The laminated structure of the agent layer 12.

[The fourth step of peeling off the adhesive sheet] After the bonding step of the second sheet 20, the fourth adhesive sheet 40 is peeled from the circuit surface W1. This step is sometimes called the peeling step of the fourth adhesive sheet. It is preferable to blend an energy ray polymerizable compound in the fourth adhesive layer 42. When an energy-ray polymerizable compound is blended in the fourth adhesive layer 42, the fourth adhesive layer 42 is irradiated with energy rays from the side of the fourth base material 41 to harden the energy-ray polymerizable compound. When the energy ray polymerizable compound is cured, the cohesive force of the fourth adhesive layer 42 is increased, and the adhesive force between the fourth adhesive layer 42 and the semiconductor chip CP can be reduced or disappeared. Therefore, the fourth adhesive sheet 40 is easily peeled off. As the energy ray, for example, ultraviolet (UV) or electron beam (EB), etc. are exemplified, and ultraviolet is preferable. When the fourth adhesive sheet 40 is peeled off, a plurality of semiconductor chips CP supported by the second sheet 20 are obtained, so it is preferable to perform the same expansion steps as in the first embodiment and the like. Regarding the extension method of the fourth embodiment and the method of manufacturing a semiconductor device including the extension method, other aspects can be implemented in the same manner as in the first embodiment.

[Effects of this embodiment] According to the expansion method of this embodiment, similar to the first embodiment, the tape structure and manufacturing process can be simplified and residual sticking can be suppressed compared with the prior art. Furthermore, it is possible to provide a method of manufacturing a semiconductor device including the extension method of this embodiment. In addition, according to this embodiment, the first base material 11 can be peeled off while the plurality of semiconductor chips CP are supported by the fourth adhesive sheet 40. Therefore, the first base material 11 is easily peeled off, and it is also possible to prevent the scattering of the plural semiconductor wafers CP.

[Changes in implementation form] The present invention is not limited to the above-mentioned embodiment. The present invention includes aspects such as changes to the above-mentioned embodiments within the scope of achieving the purpose of the invention. For example, the semiconductor wafer or the circuits in the semiconductor wafer are not limited to the arrangement or shape shown in the figure. The connection structure of the semiconductor package and the external terminal electrode is not limited to the aspect described in the foregoing embodiment. In the foregoing embodiment, the FO-WLP type semiconductor package is manufactured as an example for description, but the present invention is also applicable to the manufacture of fan-in type WLP and other semiconductor packages. The manufacturing method of the above-mentioned FO-WLP may change part of the steps, or omit part of the steps. In one aspect, the first adhesive sheet is a sheet in which the first substrate and the first adhesive layer are directly laminated as in the previous embodiment. In one aspect, the first substrate and the first adhesive are laminated A sheet with an intermediate adhesive layer between the layers, but the present invention is not limited to these aspects. For example, it may be a sheet having a release layer between the first base material and the first adhesive layer. The release layer is preferably composed of the same material as the release sheet in the description of the first embodiment.

The cutting in the cutting step can also be performed by irradiating the semiconductor wafer with laser light instead of using the above-mentioned cutting mechanism. For example, by irradiating laser light, semiconductor wafers can also be completely broken and singulated into plural semiconductor wafers. In these methods, the laser light can also be irradiated from either side of the semiconductor wafer. In the first embodiment, the first adhesive sheet 10 is attached to the back surface W3 as the second wafer surface, and the expansion method and the manufacturing method of the semiconductor device including the expansion method are described. However, the present invention is not limited to this. And so on. For example, the first adhesive sheet 10 may be pasted on the circuit surface W1 which is the first wafer surface, and the expansion method and the manufacturing method of the semiconductor device including the expansion method may be implemented as in the foregoing embodiment. Example

The following examples illustrate the present invention in further detail. The present invention is not limited to these embodiments. (Making of adhesive sheet) [Example 1] 62 parts by mass of butyl acrylate (BA), 10 parts by mass of methyl methacrylate (MMA), and 28 parts by mass of 2-hydroxyethyl acrylate (2HEA) were copolymerized to obtain an acrylic copolymer. To prepare the acrylic copolymer, add 2-isocyanatoethyl methacrylate (manufactured by Showa Denko Co., Ltd., product name "CURRANTS MOI" (registered trademark)) with a resin (acrylic acid A) solution (main adhesive agent) Agent, solid content 35.0 mass%). The addition rate is 100 mol% for 2HEA of acrylic copolymer and 90 mol% for 2-isocyanatoethyl methacrylate. The weight average molecular weight (Mw) of the obtained resin (acrylic acid A) was 600,000, and Mw/Mn was 4.5. The weight average molecular weight Mw and the number average molecular weight Mn in terms of standard polystyrene were measured by the gel permeation chromatography (GPC) method, and the molecular weight distribution (Mw/Mn) was obtained from each measurement value. Add UV resin A (10-functional urethane acrylate, manufactured by Mitsubishi Chemical Co., Ltd., product name "UV-5806", Mw=1740, containing photopolymerization initiator) to the main adhesive of the adhesive and as Toluene diisocyanate-based crosslinking agent of crosslinking agent (manufactured by Japan Polyurethane Industry Co., Ltd., product name "CORONATE L"). For the solid content of the adhesive main agent 100 parts by mass, 50 parts by mass of UV resin A are added, and 0.2 parts by mass of crosslinking agent is added. After the addition, it was stirred for 30 minutes to prepare an adhesive composition A1.

Next, apply the prepared adhesive composition A1 solution to a polyethylene terephthalate (PET) release film (manufactured by LINTEC Co., Ltd., product name "SP-PET381031", thickness 38μm) and dry , Form a 40μm thick adhesive layer on the release film. Regarding this adhesive layer, in this embodiment, it corresponds to the description in the previous embodiment, but it may be called the second adhesive layer. After attaching the second adhesive layer as a base polyester-based polyurethane elastomer sheet (manufactured by SHEEDOM Co., Ltd., product name "HIGRESS DUS202", thickness 100μm), the ends in the width direction are cut off No part, make adhesive sheet SA1. Regarding this substrate, in this embodiment, it corresponds to the description in the foregoing embodiment, but may be referred to as the second substrate.

(Measurement method of chip spacing) The adhesive sheet SA1 obtained in Example 1 was cut into 210 mm×210 mm to obtain a test sheet. At this time, the cutting is performed so that each side of the cut sheet becomes parallel or perpendicular to the MD direction of the second base material of the adhesive sheet. Prepare the semiconductor wafer to be attached to the adhesive sheet in the following sequence. The first adhesive sheet (manufactured by LINTEC Co., Ltd., quality name "LC2850(25)") is pasted on a 6-inch silicon wafer. Since the first adhesive sheet (LC2850(25)) is a thermosetting type, the first adhesive sheet is adhered to the silicon wafer and heated to harden the first adhesive layer of the first adhesive sheet to obtain a cured film. Next, cut the silicon wafer and the hardened film from the side of the 6-inch silicon wafer so that the 3mm×3mm size of the chip becomes 5 rows in the X-axis direction and the Y-axis direction becomes 5 rows, cutting out a total of 25 chips . Paste the cut hardened film on each chip. The peeling film of the peeling test sheet is attached to the cured film side of the 25 wafers cut out above at the center of the exposed second adhesive layer. At this time, the wafers are arranged in 5 rows in the X-axis direction and 5 rows in the Y-axis direction. Next, the test sheet attached with the chip is set in a biaxially extendable expansion device (spacer device). A top view illustrating the expansion device 100 is shown in FIG. 9. In Figure 9, the X axis and the Y axis are orthogonal to each other, the positive direction of the X axis is set to the +X axis direction, the negative direction of the X axis is set to the -X axis direction, and the positive direction of the Y axis Set as the +Y axis direction, and the negative direction of the Y axis as the -Y axis direction. The test sheet 200 is installed in the expansion device 100 so that each side is parallel to the X axis or the Y axis. As a result, the MD direction of the substrate in the test sheet 200 is parallel to the X axis or the Y axis. In addition, the wafer is omitted in FIG. 9.

As shown in FIG. 9, the expansion device 100 includes five holding mechanisms 101 (20 holding mechanisms 101 in total) in the +X axis direction, the -X axis direction, the +Y axis direction, and the -Y axis direction, respectively. Among the five holding mechanisms 101 in each direction, the holding mechanism 101A is located at both ends, the holding mechanism 101C is located at the center, and the holding mechanism 101B is located between the holding mechanism 101A and the holding mechanism 101C. Each side of the test sheet 200 is grasped by the holding mechanisms 101. Here, as shown in FIG. 9, one side of the test sheet 200 is 210 mm. And the distance between the holding mechanisms 101 on each side is 40 mm. The distance between the end of one side of the test sheet 200 (the apex of the sheet) and the holding mechanism 101A closest to the end of the test sheet 200 is 25 mm. Next, a plurality of tension applying mechanisms (not shown) corresponding to the holding mechanisms 101 are driven to move the holding mechanisms 101 independently. Fix the four sides of the test sheet with a pinch jig, and expand the test sheet at a speed of 5mm/s in the X-axis direction and the Y-axis direction with an expansion of 200mm. Subsequently, the expanded state of the test sheet 200 was maintained by the ring frame. While maintaining the expanded state, the distance between each wafer was measured with a digital microscope, and the average value of the distance between each wafer was set as the wafer interval. If the wafer spacing is 1800μm or more, it will be judged as "A", and if the wafer spacing is less than 1800μm, it will be judged as "B".

(Measurement method of chip alignment) Measure the deviation rate from the center line of adjacent wafers in the X-axis and Y-axis directions of the workpiece whose wafer spacing is measured. Figure 10 shows a schematic diagram of a specific measurement method. Select a row of 5 chips arranged in the X-axis direction, and measure the distance Dy between the uppermost end of the chip and the lowermost end of the chip in this row with a digital microscope. Calculate the offset rate in the Y-axis direction based on the following formula (Equation 3). Sy is the size of the wafer in the Y-axis direction, which is set to 3 mm in this embodiment. Y-axis deviation rate [%]=[(Dy-Sy)/2]/Sy×100･･･(number 3) For the other four rows in which 5 chips are arranged in the X-axis direction, the offset rate in the Y-axis direction is also calculated. Choose a row of 5 chips arranged in the Y-axis direction, in this row, measure the distance Dx between the leftmost end of the chip and the rightmost end of the chip with a digital microscope. The offset rate in the X-axis direction is calculated based on the following formula (Equation 4). Sx is the size of the wafer in the X-axis direction, and is set to 3 mm in this embodiment. Offset rate in the X-axis direction [%]=[(Dx-Sx)/2]/Sx×100･･･(number 4) For the other four rows of 5 chips arranged in the Y-axis direction, the offset rate in the X-axis direction is also calculated. In the formulas (Equation 3) and (Equation 4), the reason for dividing by 2 is to express the maximum distance of the chip from a specific position after expansion as an absolute value. Among all rows in the X-axis direction and Y-axis direction (10 rows), if the deviation rate is less than ±10%, it is judged as “A”, and if the deviation rate is more than ±10%, it is judged as unqualified. B".

(Evaluation method of residual paste) After expanding the conditions described in the above-mentioned wafer spacing measurement method, using an ultraviolet irradiation device (“RAD-2000 m/12” manufactured by LINTEC Co., Ltd.), and the adhesive sheet of Example 1 the wafer mounting surface opposite to the side at an intensity of 220mW / cm ^2, light quantity of 460mJ / cm ² of ultraviolet irradiation conditions. After the ultraviolet ray is irradiated, the wafer is held by the suction table and the adhesive sheet is peeled off. After peeling off the adhesive sheet, observe the hardened film surface of the chip on which the adhesive sheet is attached with an optical microscope. The case where no residue is observed on the surface of the hardened film of the chip is judged as pass "A", and the case where residue is observed is judged as unqualified "B". After using the adhesive sheet of Example 1 to expand, the evaluation result of the chip spacing was a pass "A" judgment, and the evaluation result of the wafer alignment was a pass "A" judgment. After the first adhesive layer (cured film) is interposed between the chip and the adhesive sheet of the embodiment and the adhesive sheet is expanded, the evaluation result of the residue on the cured film surface of the chip is a pass "A" judgment.

3: Sealing body 3A: Noodles 10, 10A: The first adhesive sheet 11: The first substrate 12: The first adhesive layer 13: Middle adhesive layer 20, 20A: second slice 21, 21A: Second base material 22: The second adhesive layer 30: The third adhesive sheet 31: The third substrate 32: The third adhesive layer 40: The fourth adhesive sheet 41: 4th substrate 42: The fourth adhesive layer 100: Expansion device 101, 101A, 101B, 101C: holding mechanism 200: test sheet 300: Sealing member W: semiconductor wafer W1: circuit surface W2: Circuit W3: Back CP: Semiconductor wafer Sx: Chip size in X axis direction Sy: Chip size in Y axis direction Dx: The distance between the leftmost end of the chip and the rightmost end of the chip Dy: the distance between the top end of the chip and the bottom end of the chip D1: interval

[Fig. 1A] is a cross-sectional view explaining the manufacturing method of the first embodiment. [Fig. 1B] is a cross-sectional view explaining the manufacturing method of the first embodiment. [Fig. 2A] is a cross-sectional view explaining the manufacturing method of the first embodiment. [Fig. 2B] is a cross-sectional view explaining the manufacturing method of the first embodiment. [Fig. 3] is a cross-sectional view explaining the manufacturing method of the first embodiment. [Fig. 4A] is a cross-sectional view explaining the manufacturing method of the first embodiment. [Fig. 4B] is a cross-sectional view explaining the manufacturing method of the first embodiment. [Fig. 5] is a cross-sectional view explaining the manufacturing method of the second embodiment. [Fig. 6] is a cross-sectional view explaining the manufacturing method of the second embodiment. [Fig. 7A] is a cross-sectional view explaining the manufacturing method of the third embodiment. [Fig. 7B] is a cross-sectional view explaining the manufacturing method of the third embodiment. [Fig. 7C] is a cross-sectional view explaining the manufacturing method of the third embodiment. [Fig. 8A] is a cross-sectional view explaining the manufacturing method of the fourth embodiment. [Fig. 8B] is a cross-sectional view explaining the manufacturing method of the fourth embodiment. [Fig. 8C] is a cross-sectional view explaining the manufacturing method of the fourth embodiment. [Figure 9] is a top view illustrating the biaxial extension and expansion device used in the embodiment. [Fig. 10] A schematic diagram for explaining the measurement method of wafer alignment.

12: The first adhesive layer

20: 2nd slice

21: The second substrate

22: The second adhesive layer

W1: circuit surface

W2: Circuit

W3: Back

CP: Semiconductor wafer

Claims (12)

An expansion method is to attach the second wafer surface of the wafer having the first wafer surface and the second wafer surface on the opposite side of the first wafer surface, and attach the first adhesive layer and the second wafer surface 1 The first adhesive sheet of the substrate, Cut a cut from the first wafer surface side, separate the wafer into a plurality of wafers, and further cut the first adhesive layer, Peeling off the first base material from the first adhesive layer, Attach the second sheet to the aforementioned first adhesive layer, The second sheet is stretched to enlarge the interval between the plurality of wafers. Such as the extension method of claim 1, in which, The notch is formed to reach the depth of the first base material. Such as the extension method of claim 1, in which, The first adhesive layer contains a first energy ray curable resin. Such as the extension method of claim 1, in which, The aforementioned second sheet is an expanded sheet. Such as the extension method of claim 1, in which, The aforementioned second sheet has a second adhesive layer and a second substrate, The second adhesive layer contains a second energy ray curable resin. Such as the extension method of claim 1, in which, The peeling force when the first base material is peeled from the first adhesive layer is 10 mN/25mm or more and 2000 mN/25mm or less. Such as the extension method of claim 1, in which, The first adhesive sheet has a release layer between the first base material and the first adhesive layer. Such as the extension method of claim 1, in which, After the first base material is peeled from the first adhesive layer, the plurality of wafers to which the first adhesive layer is attached are held by a holding member, The second sheet is attached to the first adhesive layer attached to the plurality of chips held by the holding member. Such as the extension method of claim 1, in which, After the wafer is singulated into a plurality of chips, the first adhesive sheet is stretched to expand the interval between the plurality of chips. Such as the extension method of claim 1, in which, The aforementioned wafer is a semiconductor wafer. Such as the extension method of any one of claims 1 to 10, where: The first wafer surface has a circuit. A method of manufacturing a semiconductor device, which includes the extension method as described in any one of claims 1 to 11.

Images