CN113366080B

CN113366080B - Wafer expanding method and method for manufacturing semiconductor device

Info

Publication number: CN113366080B
Application number: CN202080011754.0A
Authority: CN
Inventors: 布施启示; 稻男洋一; 山田忠知
Original assignee: Lintec Corp
Current assignee: Lintec Corp
Priority date: 2019-01-31
Filing date: 2020-01-29
Publication date: 2023-12-26
Anticipated expiration: 2040-01-29
Also published as: JPWO2020158766A1; KR20210123318A; TW202044384A; WO2020158766A1; CN113366080A

Abstract

The invention provides a method for expanding a slice, which comprises the following steps: and a step of expanding the 1 st sheet (10) on which the plurality of semiconductor devices (CP) are bonded so as to expand the intervals between the plurality of semiconductor devices (CP), wherein the plurality of semiconductor devices (CP) each have a 1 st semiconductor device surface (W1) and a 2 nd semiconductor device surface (W3) on the opposite side of the 1 st semiconductor device surface (W1), and the plurality of semiconductor devices (CP) are bonded so as to include a protective layer (100) between the 2 nd semiconductor device surface (W3) and the 1 st sheet (10).

Description

Wafer expanding method and method for manufacturing semiconductor device

Technical Field

The present invention relates to a dicing method and a method for manufacturing a semiconductor device.

Background

In recent years, miniaturization, weight saving, and higher functionality of electronic devices have been advanced. A semiconductor device mounted on an electronic device is also required to be small, thin, and high in density. Semiconductor chips are sometimes mounted on packages that are close to their size. Such packages are sometimes also referred to as chip scale packages (Chip Scale Package; CSP). One example of CSP is a wafer level package (Wafer Level Package; WLP). In WLP, external electrodes and the like are formed on a wafer before singulation by dicing, and finally the wafer is diced to singulate. As WLP, fan-In (Fan-In) type and Fan-Out (Fan-Out) type may be cited. In a fan-out WLP (hereinafter, also referred to simply as "FO-WLP"), a semiconductor chip is covered with a sealing material to a region larger than the chip size, and a semiconductor chip sealing body is formed, and a rewiring layer and an external electrode are formed not only on the circuit surface of the semiconductor chip but also on the surface region of the sealing material.

For example, patent document 1 describes a method for manufacturing a semiconductor package, the method including: the semiconductor package is formed by forming an extension wafer by surrounding a circuit forming surface of a plurality of semiconductor chips formed by singulating a semiconductor wafer with a mold member, and extending a rewiring pattern to an area outside the semiconductor chips. In the manufacturing method described in patent document 1, before surrounding the singulated semiconductor chips with the mold member, the die attach tape for dicing is transferred and adhered to the dicing die attach tape, and the die attach tape is extended to expand the distance between the semiconductor chips.

Patent document 2 describes an adhesive sheet comprising, in order, a second base layer, a first base layer, and a first adhesive layer, wherein the second base layer has an elongation at break of 400% or more. The method for manufacturing a semiconductor device described in patent document 2 includes: bonding a semiconductor wafer to a first adhesive layer of the adhesive sheet; a step of dicing the semiconductor wafer to form a plurality of semiconductor chips; and stretching the adhesive sheet to expand the interval between the semiconductor chips.

Prior art literature

Patent literature

Patent document 1: international publication No. 2010/058646

Patent document 2: japanese patent laid-open No. 2017-076758

Disclosure of Invention

Problems to be solved by the invention

The tape used in the dicing step generally has an adhesive layer for fixing the semiconductor chip on the tape, and a base material for supporting the adhesive layer. When the die attach tape for dicing is stretched as described in patent document 1, not only the base material and the adhesive layer of the tape but also the adhesive layer are stretched. When the semiconductor chip is peeled from the adhesive layer after the dicing step, there is a case where the adhesive layer remains on the surface of the semiconductor chip that is in contact with the adhesive layer. In this specification, such a problem is sometimes referred to as a residual glue.

When the dicing step is performed using the pressure-sensitive adhesive sheet described in patent document 2, it is considered that the pressure-sensitive adhesive layer that is in contact with the semiconductor chip is not stretched, and therefore, the occurrence of the adhesive residue is less likely to occur. However, the pressure-sensitive adhesive sheet described in patent document 2 has a tape structure in which a second base layer, a first base layer, and a first pressure-sensitive adhesive layer are laminated, and therefore, there is a demand for a sheet-spreading method capable of preventing adhesive residue by using a simpler tape structure. In the process described in patent document 2, the semiconductor wafer on the adhesive sheet is cut, and the adhesive sheet is stretched without being transferred to another adhesive sheet, thereby performing a dicing step. Accordingly, the depth of the cut mark of the cutting blade needs to be carefully controlled so that the cutting blade does not reach the second base material layer at the time of cutting, and thus there is also a demand for a dicing method capable of preventing the residual glue by a simpler method.

In the dicing method, examples of the adherend supported by the pressure-sensitive adhesive sheet include not only semiconductor chips but also semiconductor devices such as wafers, semiconductor device packages, and micro LEDs. In these semiconductor devices, the intervals between the semiconductor devices may be widened in the same manner as the semiconductor chips.

The invention aims to provide a dicing method capable of simplifying at least one of tape constitution and process and suppressing residual glue compared with the prior art, and a method for manufacturing a semiconductor device comprising the dicing method.

Means for solving the problems

According to an embodiment of the present invention, there may be provided a method of expanding a slice, the method including: and a step of expanding a 1 st sheet on which a plurality of semiconductor devices are bonded to expand a space between the plurality of semiconductor devices, wherein the plurality of semiconductor devices each have a 1 st semiconductor device surface and a 2 nd semiconductor device surface on the opposite side of the 1 st semiconductor device surface, and the plurality of semiconductor devices are bonded to each other by including a protective layer between the 1 st semiconductor device surface or the 2 nd semiconductor device surface and the 1 st sheet.

In the dicing method according to one embodiment of the present invention, it is preferable that the plurality of semiconductor devices are bonded to the 1 st wafer after the protective layer is formed on the 1 st semiconductor device surface.

In the dicing method according to one embodiment of the present invention, it is preferable that the plurality of semiconductor devices are obtained by cutting the object to be processed.

In the dicing method according to one aspect of the present invention, it is preferable that the protective layer is formed on the object, and the object and the protective layer are cut to obtain the plurality of semiconductor devices.

In the dicing method according to one embodiment of the present invention, it is preferable that the object on which the protective layer is formed is bonded to the 2 nd adhesive layer of the 2 nd adhesive sheet having the 2 nd adhesive layer and the 2 nd base material, the protective layer and the object are cut to obtain the plurality of semiconductor devices, and the 1 st sheet is bonded to the protective layer after cutting.

In the dicing method according to one embodiment of the present invention, it is preferable that the 2 nd adhesive sheet is peeled off after the 1 st sheet is bonded to the cut protective layer.

In the dicing method according to one embodiment of the present invention, it is preferable that the object is bonded to the protective layer of the composite sheet having the protective layer and the 3 rd piece, the object and the protective layer are cut to obtain the plurality of semiconductor devices, and the 3 rd piece is peeled from the protective layer.

In the dicing method according to one embodiment of the present invention, it is preferable that the protective layer and the 1 st piece are stacked in advance, the object is supported by the protective layer, and the object and the protective layer are cut to obtain the plurality of semiconductor devices.

In the dicing method according to one embodiment of the present invention, the object is preferably a semiconductor wafer.

In the method for expanding a sheet according to one embodiment of the present invention, the 1 st sheet is preferably an expanded sheet.

In the dicing method according to one embodiment of the present invention, it is preferable that the 1 st semiconductor device surface has a circuit.

According to an embodiment of the present invention, a method for manufacturing a semiconductor device including the method for expanding a wafer according to the above embodiment of the present invention can be provided.

According to one embodiment of the present invention, a method for expanding a tape, which can simplify at least one of the tape structure and the process and can suppress the residual adhesive, as compared with the conventional method, can be provided. According to another embodiment of the present invention, a method for manufacturing a semiconductor device including the dicing method can be provided.

Drawings

Fig. 1A is a cross-sectional view illustrating a manufacturing method according to embodiment 1.

Fig. 1B is a cross-sectional view illustrating a manufacturing method according to embodiment 1.

Fig. 1C is a cross-sectional view illustrating a manufacturing method according to embodiment 1.

Fig. 2A is a cross-sectional view illustrating the manufacturing method according to embodiment 1.

Fig. 2B is a cross-sectional view illustrating the manufacturing method according to embodiment 1.

Fig. 3 is a cross-sectional view illustrating a manufacturing method according to embodiment 1.

Fig. 4A is a cross-sectional view illustrating the manufacturing method according to embodiment 1.

Fig. 4B is a cross-sectional view illustrating the manufacturing method according to embodiment 1.

Fig. 5A is a cross-sectional view illustrating the manufacturing method according to embodiment 1.

Fig. 5B is a cross-sectional view illustrating the manufacturing method according to embodiment 1.

Fig. 6A is a cross-sectional view illustrating a manufacturing method according to embodiment 2.

Fig. 6B is a cross-sectional view illustrating the manufacturing method according to embodiment 2.

Fig. 6C is a cross-sectional view illustrating the manufacturing method according to embodiment 2.

Fig. 7A is a cross-sectional view illustrating a manufacturing method according to embodiment 2.

Fig. 7B is a cross-sectional view illustrating a manufacturing method according to embodiment 2.

Fig. 7C is a cross-sectional view illustrating the manufacturing method according to embodiment 2.

Fig. 8A is a cross-sectional view illustrating a manufacturing method according to embodiment 3.

Fig. 8B is a cross-sectional view illustrating the manufacturing method according to embodiment 3.

Fig. 8C is a cross-sectional view illustrating the manufacturing method according to embodiment 3.

Fig. 9 is a cross-sectional view illustrating a manufacturing method according to embodiment 3.

Fig. 10 is a plan view illustrating a biaxially oriented panel device used in the examples.

Fig. 11 is a schematic diagram for explaining a method of measuring chip alignment.

Symbol description

10 … 1 st piece,

100. 100A, 100B … protective layer,

11 … No. 1 base material,

12 … adhesive layer 1,

130. 140 … composite sheet,

20 … the 2 nd adhesive sheet,

W … semiconductor wafer (object),

W1 … circuit face (1 st semiconductor device face),

W3 … back side (semiconductor device side 2).

Detailed Description

[ embodiment 1 ]

Hereinafter, a method for manufacturing a semiconductor device including the method for expanding a wafer according to the present embodiment will be described.

Fig. 1 (fig. 1A, 1B, and 1C), fig. 2 (fig. 2A and 2B), fig. 3, 4 (fig. 4A and 4B), and fig. 5 (fig. 5A and 5B) are schematic cross-sectional views illustrating a method of manufacturing a semiconductor device including a dicing method according to the present embodiment.

The method for expanding a sheet according to the present embodiment includes at least the following steps (P1) to (P2).

(P1) a step of preparing a plurality of semiconductor devices bonded to the 1 st wafer. The plurality of semiconductor devices and the 1 st chip are bonded together with a protective layer interposed therebetween.

(P2) stretching the 1 st sheet to expand the interval between the plurality of semiconductor devices.

Fig. 1A, 1B, 1C, 2A, and 2B are diagrams for explaining the step (P1).

(object to be processed)

Fig. 1A is a schematic cross-sectional view of a processing object having a protective layer.

In the present embodiment, a semiconductor wafer W as a processing target is described as an example. In the present invention, the object to be processed is not limited to a wafer.

The semiconductor wafer W has a circuit surface W1 as a 1 st object surface and a back surface W3 as a 2 nd object surface. A circuit W2 is formed on the circuit surface W1. In the present embodiment, the protective layer 100 is provided on the circuit surface W1.

The semiconductor wafer W may be, for example, a silicon wafer or a compound semiconductor wafer such as gallium arsenic. As a method for forming the circuit W2 on the circuit surface W1 of the semiconductor wafer W, general methods such as etching and Lift-off (Lift-off) are mentioned.

(protective layer)

The protective layer 100 is a layer covering the circuit surface W1 and the circuit W2. The protective layer 100 is not particularly limited as long as it can protect the circuit surface W1 and the circuit W2. The thickness of the protective layer 100 is preferably 1 μm or more, more preferably 5 μm or more. The thickness of the protective layer 100 is preferably 500 μm or less, more preferably 300 μm or less.

As the protective layer 100, for example, there can be mentioned: a protective film, and a protective sheet.

The protective film is preferably a film formed by, for example, forming a resin material on the circuit surface W1. The protective film may be formed of one layer or two or more layers. Examples of the film forming method include: printing, spraying, spin coating and dipping.

Examples of the protective sheet include an adhesive sheet having an adhesive layer and a base material. The base material of the protective sheet is not particularly limited as long as it can function properly as one of the members constituting the protective layer and supports the pressure-sensitive adhesive layer. The base material in the protective sheet is preferably formed of a film mainly composed of a resin-based material. Examples of the film containing a resin-based material as a main material include: olefinic copolymer film, polyolefin film, polyvinyl chloride film, polyester film, polyurethane film, polyimide film, polystyrene film, polycarbonate film, and fluororesin film.

The pressure-sensitive adhesive layer in the protective sheet is not particularly limited as long as it can function properly as one of the members constituting the protective layer and is adhered to the base material and the circuit surface W1. The pressure-sensitive adhesive layer in the protective sheet is preferably formed of at least one pressure-sensitive adhesive selected from, for example, an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, a polyester pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, and a silicone pressure-sensitive adhesive, and more preferably formed of an acrylic pressure-sensitive adhesive.

In the present embodiment, the case where the protective layer 100 is a protective film formed of one layer has been described as an example, but the present invention is not limited to this embodiment.

[ Back grinding Process ]

The semiconductor wafer W is preferably a wafer obtained by a back grinding process. The step (P1) of preparing a plurality of semiconductor devices bonded to the 1 st wafer preferably includes the back grinding step as the step (P1-1).

In the back grinding step, the surface of the semiconductor wafer W opposite to the circuit surface W1 is ground to a predetermined thickness. The back surface W3 is preferably a surface formed by back grinding the semiconductor wafer W. The surface exposed after grinding the semiconductor wafer W is referred to as the back surface W3.

The method for grinding the semiconductor wafer W is not particularly limited, and a known method using a grinder or the like may be used. In grinding the semiconductor wafer W, an adhesive sheet called a back grinding sheet is preferably bonded to the circuit surface W1 in order to protect the circuit W2. In the back surface grinding of the wafer, the circuit surface W1 side, that is, the back grinding sheet side of the semiconductor wafer W is fixed by a chuck table or the like, and the back surface side on which the circuit is not formed is ground by a grinder. The step of bonding the back grinding sheet to the circuit surface W1 is also referred to as a bonding step of the back grinding sheet.

The thickness of the semiconductor wafer W before grinding is not particularly limited, and is usually 500 μm or more and 1000 μm or less.

The thickness of the semiconductor wafer W after grinding is not particularly limited, and is usually 20 μm or more and 500 μm or less.

[ bonding step of the 2 nd pressure-sensitive adhesive sheet ]

Fig. 1B shows a semiconductor wafer W having a 2 nd adhesive sheet 20 attached to a back surface W3.

The semiconductor wafer W prepared in the step (P1) is preferably a wafer obtained by a back grinding step and a bonding step of bonding the 2 nd adhesive sheet 20 to the back surface W3. This bonding step is sometimes referred to as a bonding step of the 2 nd pressure-sensitive adhesive sheet.

As described later, in the step (P2), the semiconductor wafer W is diced and singulated into a plurality of semiconductor chips CP. When dicing the semiconductor wafer W, an adhesive sheet called dicing sheet is preferably bonded to the back surface W3 in order to hold the semiconductor wafer W. In the present embodiment, the 2 nd adhesive sheet 20 is preferably a cut sheet. When the 2 nd adhesive sheet 20 is used as the dicing sheet, the back surface W3 of the semiconductor wafer W is bonded to the 2 nd adhesive layer 22 of the 2 nd adhesive sheet 20. The circuit surface W1 of the semiconductor wafer W corresponds to the circuit surface W1 of the semiconductor chip CP. The back surface W3 of the semiconductor wafer W corresponds to the back surface W3 of the semiconductor chip CP.

[ cutting procedure ]

Fig. 1C is a diagram for explaining a dicing process for dicing a semiconductor wafer W as a processing target. Fig. 1C shows a plurality of semiconductor chips CP held by the 2 nd adhesive sheet 20. In the present embodiment, the semiconductor chip CP is described as an example of the semiconductor device, but the present invention is not limited to such an embodiment. Examples of the semiconductor device include: a die, a semiconductor device package, and a micro LED.

The plurality of semiconductor devices prepared in the step (P1) are preferably a plurality of semiconductor chips CP obtained by dicing the semiconductor wafer W in the dicing step. The step (P1) preferably includes a dicing step of dicing the semiconductor wafer W supported by the 2 nd adhesive sheet 20 as the step (P1-2).

The protective layer 100 is provided on the circuit surface W1, and the semiconductor wafer W in a state where the 2 nd adhesive sheet 20 is bonded to the back surface W3 is diced into individual pieces to form a plurality of semiconductor chips CP. In the present embodiment, a dicing mark is cut from the protective layer 100 side, the protective layer 100 is cut, and the semiconductor wafer W is further cut. The circuit surfaces W1 of the plurality of semiconductor chips CP after the dicing step are covered with the protection layer 100 after the dicing step.

Cutting may use a cutting mechanism such as a microtome (dicing saw).

The dicing depth at the dicing is not particularly limited as long as the protective layer 100 and the semiconductor wafer W can be singulated. From the viewpoint of reliably cutting the semiconductor wafer W, the dicing mark in the dicing step is preferably formed at a depth from the protective layer 100 side up to the 2 nd adhesive sheet 20, and more preferably at a depth up to the 2 nd adhesive layer 22 of the 2 nd adhesive sheet 20. By dicing, the 2 nd adhesive layer 22 is also diced into the same size as the semiconductor chip CP. In addition, a dicing mark may be formed in the 2 nd base material 21 by dicing.

[ bonding step of sheet 1 ]

Fig. 2A is a diagram for explaining a step of bonding the 1 st sheet 10 to the plurality of semiconductor chips CP after the dicing step. Fig. 2A shows a state in which the 1 st sheet 10 is attached to a plurality of semiconductor chips CP obtained by the dicing process. The 1 st sheet 10 of the present embodiment is an adhesive sheet having a 1 st adhesive layer 12 and a 1 st base material 11. Details of the 1 st sheet 10 are described later. In the present invention, the 1 st sheet is not limited to the adhesive sheet having a two-layer structure of the 1 st adhesive layer and the 1 st base material.

In the present embodiment, when the 1 st sheet 10 is bonded to the circuit surface W1 side of the plurality of semiconductor chips CP, a laminated structure in which the plurality of semiconductor chips CP and the 1 st adhesive layer 12 of the 1 st sheet 10 are sandwiched by the singulated protective layers 100 can be obtained.

[ step of peeling the 2 nd pressure-sensitive adhesive sheet ]

Fig. 2B is a diagram for explaining a step of peeling the 2 nd pressure-sensitive adhesive sheet 20 after the lamination step of the 1 st sheet. This step is sometimes referred to as a step of peeling the 2 nd pressure-sensitive adhesive sheet. Fig. 2B shows a state in which the 2 nd adhesive sheet 20 is peeled off from the back surface W3 of the semiconductor wafer W after the 1 st sheet 10 is bonded.

When the 2 nd adhesive sheet 20 is peeled off after the 1 st sheet 10 is bonded, the back surfaces W3 of the plurality of semiconductor chips CP are exposed.

When the 2 nd pressure-sensitive adhesive layer 22 is blended with an energy ray polymerizable compound, it is preferable that the 2 nd pressure-sensitive adhesive layer 22 is irradiated with energy rays from the 2 nd base material 21 side, and the 2 nd pressure-sensitive adhesive sheet 20 is peeled after the energy ray polymerizable compound is cured.

[ step of expanding sheet ]

Fig. 3 is a diagram for explaining the step (P2). The process (P2) is sometimes referred to as a dicing step. Fig. 3 shows a state in which the 1 st sheet 10 is stretched to expand the intervals of the plurality of semiconductor chips CP after the 2 nd adhesive sheet 20 is peeled off.

When the intervals between the plurality of semiconductor chips CP are enlarged, it is preferable to stretch the extension sheet in a state where the plurality of semiconductor chips CP are held by an adhesive sheet called an extension sheet. In the present embodiment, the 1 st sheet 10 is preferably an extension sheet.

The method for stretching the 1 st sheet 10 in the sheet stretching step is not particularly limited. Examples of the method for stretching the 1 st sheet 10 include: a method of stretching the 1 st sheet 10 by being put on an endless or circular expander, a method of stretching the 1 st sheet 10 by grasping the outer peripheral portion of the 1 st sheet 10 with a grasping member or the like, and the like. In the present embodiment, the interval D1 of the plurality of semiconductor chips CP depends on the size of the semiconductor chip CP, and is therefore not particularly limited. In particular, the distance D1 between adjacent semiconductor chips CP among the plurality of semiconductor chips CP bonded to one surface of the adhesive sheet is preferably 200 μm or more. The upper limit of the interval between the semiconductor chips CP is not particularly limited. The upper limit of the interval between the semiconductor chips CP may be 6000 μm, for example.

[ transfer Process 1 ]

In the present embodiment, a step of transferring the plurality of semiconductor chips CP bonded to the 1 st sheet 10 to another adhesive sheet (for example, a 5 th adhesive sheet) (hereinafter, sometimes referred to as "1 st transfer step") may be performed after the sheet expanding step.

Fig. 4A shows a diagram illustrating a process of transferring a plurality of semiconductor chips CP bonded to the 1 st sheet 10 to the 5 th adhesive sheet 50 (hereinafter, sometimes referred to as a "transfer process").

The 5 th adhesive sheet 50 is not particularly limited as long as it can hold a plurality of semiconductor chips CP. The 5 th adhesive sheet 50 has a 5 th base material 51 and a 5 th adhesive layer 52.

In the case of performing the transfer step in the present embodiment, for example, after the dicing step, the 5 th adhesive sheet 50 is preferably bonded to the back surface W3 of the plurality of semiconductor chips CP, and then the 1 st sheet 10 is peeled off.

The 5 th adhesive sheet 50 may be attached to the second ring frame together with the plurality of semiconductor chips CP. In this case, the ring frame is placed on the 5 th adhesive layer 52 of the 5 th adhesive sheet 50, and is fixed by being lightly pressed. Then, the 5 th adhesive layer 52 exposed on the inner side of the ring shape of the ring frame is pressure-bonded to the back surface W3 of the semiconductor chip CP, and the plurality of semiconductor chips CP are fixed to the 5 th adhesive sheet 50.

Fig. 4B is a diagram illustrating a step of peeling the 1 st sheet 10 after the 5 th adhesive sheet 50 is attached.

In the present embodiment, the case where the 1 st sheet 10 is peeled off together with the protective layer 100 after singulation of the circuit surface W1 covering the semiconductor chip CP is described as an example. The singulated protective layer 100 covering the circuit surface W1 may be left on the semiconductor chip CP to peel off only the 1 st sheet 10.

When the 1 st sheet 10 and the protective layer 100 are peeled off after the 5 th adhesive sheet 50 is attached, the circuit surfaces W1 of the plurality of semiconductor chips CP are exposed. It is preferable that the spacing D1 between the plurality of expanded semiconductor chips CP be maintained in the dicing step even after the 1 st sheet 10 and the protective layer 100 are peeled off.

[ transfer procedure 2 ]

Fig. 5A shows a process of transferring a plurality of semiconductor chips CP bonded to the 5 th adhesive sheet 50 to the 6 th adhesive sheet 60 (hereinafter, sometimes referred to as "2 nd transfer process") in the following.

The plurality of semiconductor chips CP transferred from the 5 th adhesive sheet 50 to the 6 th adhesive sheet 60 preferably maintain the interval D1 between the semiconductor chips CP.

The 6 th adhesive sheet 60 is not particularly limited as long as a plurality of semiconductor chips CP can be held. The 6 th adhesive sheet 60 has a 6 th base material 61 and a 6 th adhesive layer 62.

When the plurality of semiconductor chips CP to be sealed to the 6 th adhesive sheet 60 are to be sealed, the 6 th adhesive sheet 60 is preferably an adhesive sheet for a sealing process, and more preferably an adhesive sheet having heat resistance is used. In the case of using a heat-resistant adhesive sheet as the 6 th adhesive sheet 60, the 6 th base material 61 and the 6 th adhesive layer 62 are each preferably formed of a material having heat resistance that can withstand the temperature applied in the sealing step.

The plurality of semiconductor chips CP transferred from the 5 th adhesive sheet 50 to the 6 th adhesive sheet 60 are bonded with the circuit surface W1 facing the 6 th adhesive layer 62.

[ sealing Process ]

Fig. 5B shows a process of sealing a plurality of semiconductor chips CP using the sealing member 300 (hereinafter, sometimes referred to as a "sealing process").

In the present embodiment, the sealing process is performed after the plurality of semiconductor chips CP are transferred to the 6 th adhesive sheet 60.

In the sealing step, the plurality of semiconductor chips CP are covered with the sealing member 300 in a state where the circuit surface W1 is protected by the 6 th adhesive sheet 60, thereby forming the sealing body 3. 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 with the 6 th adhesive sheet 60, the circuit surface W1 can be prevented from being covered with the sealing member 300.

By the sealing process, the sealing body 3 in which the plurality of semiconductor chips CP separated by a predetermined distance are embedded in the sealing member 300 can be obtained. In the sealing step, the plurality of semiconductor chips CP are preferably covered with the sealing member 300 while maintaining the interval D1 after the dicing step is performed.

After the sealing step, the 6 th adhesive sheet 60 is peeled off. When the 6 th adhesive sheet 60 is peeled off, the circuit surface W1 of the semiconductor chip CP and the surface 3A of the sealing body 3, which is in contact with the 6 th adhesive sheet 60, are exposed.

After the dicing step, the transfer step and the dicing step are repeated an arbitrary number of times, whereby the distance between the semiconductor chips CP can be set to a desired distance, and the orientation of the circuit surface when the semiconductor chips CP are sealed can be set to a desired orientation.

[ other procedures ]

After the pressure-sensitive adhesive sheet is peeled off from the sealing body 3, a rewiring layer forming step of forming a rewiring layer electrically connected to the semiconductor chip CP and a connecting step of electrically connecting the rewiring layer to the external terminal electrode are sequentially performed on the sealing body 3. The circuit of the semiconductor chip CP can be electrically connected to the external terminal electrode 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 the semiconductor chip CP unit. The method of singulating the sealing body 3 is not particularly limited. By singulating the sealing body 3, a semiconductor package of the semiconductor chip CP unit can be manufactured. The semiconductor package to which the external electrode fanned out to the outside of the area of the semiconductor chip CP is connected is manufactured as a fanout wafer level package (FO-WLP).

(1 st sheet)

The 1 st sheet 10 of the present embodiment has a 1 st base material 11 and a 1 st adhesive layer 12. The 1 st adhesive layer 12 is laminated on the 1 st base material 11.

1 st substrate

The 1 st base material 11 is not particularly limited as long as it can function properly in a desired process (for example, process (P2)) such as a dicing process.

The 1 st substrate 11 has a 1 st substrate surface and a 1 st substrate back surface. The 1 st substrate back surface is a surface opposite to the 1 st substrate surface.

In the 1 st sheet 10, the 1 st adhesive layer 12 is preferably provided on one of the 1 st substrate surface and the 1 st substrate back surface, and the adhesive layer is preferably not provided on the other surface.

From the viewpoint of easy large-scale stretching, the material of the 1 st base material 11 is preferably a thermoplastic elastomer or a rubber-like material, and more preferably a thermoplastic elastomer.

In addition, as the material of the 1 st base material 11, a resin having a low glass transition temperature (Tg) is preferably used in view of easy large stretching. The glass transition temperature (Tg) of such a resin is preferably 90 ℃ or lower, more preferably 80 ℃ or lower, and further preferably 70 ℃ or lower.

As the thermoplastic elastomer, there may be mentioned: urethane-based elastomer, olefin-based elastomer, vinyl chloride-based elastomer, polyester-based elastomer, styrene-based elastomer, acrylic elastomer, amide-based elastomer, and the like. The thermoplastic elastomer may be used singly or in combination of two or more. As the thermoplastic elastomer, a urethane elastomer is preferably used in view of easy large-scale stretching.

Urethane elastomers are generally obtained by reacting a long-chain polyol, a chain extender and a diisocyanate. The urethane elastomer includes a soft segment having a structural unit derived from a long chain polyol and a hard segment having a polyurethane structure obtained by reacting a chain extender with a diisocyanate.

If classified according to the kind of long-chain polyol, urethane-based elastomers can be classified into polyester-based polyurethane elastomers, polyether-based polyurethane elastomers, polycarbonate-based polyurethane elastomers, and the like. The urethane elastomer may be used singly or in combination of two or more. In the present embodiment, the urethane elastomer is preferably a polyether polyurethane elastomer from the viewpoint of easy large-scale stretching.

Examples of the long-chain polyol include: polyester polyols such as lactone-type polyester polyols and adipic acid ester-type polyester polyols; polyether polyols such as polypropylene (ethylene) polyol and polytetramethylene ether glycol; polycarbonate polyols, and the like. In the present embodiment, the long-chain polyol is preferably an adipate polyester polyol from the viewpoint of easy substantial stretching.

As examples of the diisocyanate, there may be mentioned: 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4' -diphenylmethane diisocyanate, hexamethylene diisocyanate, and the like. In this embodiment, the diisocyanate is preferably hexamethylene diisocyanate from the viewpoint of easy substantial stretching.

As the chain extender, there may be mentioned: low molecular weight polyols (e.g., 1, 4-butanediol, 1, 6-hexanediol, etc.), aromatic diamines, etc. Among them, 1, 6-hexanediol is preferably used in view of easy large-scale stretching.

The olefin-based elastomer may be an elastomer containing at least one resin selected from the group consisting of an ethylene/α -olefin copolymer, a propylene/α -olefin copolymer, a butene/α -olefin copolymer, an ethylene/propylene/α -olefin copolymer, an ethylene/butene/α -olefin copolymer, a propylene/butene/α -olefin copolymer, an ethylene/propylene/butene/α -olefin copolymer, a styrene/isoprene copolymer, and a styrene/ethylene/butene copolymer. The olefin-based elastomer may be used singly or in combination of two or more.

The density of the olefin elastomer is not particularly limited. For example, the olefin elastomer preferably has a density of 0.860g/cm ³ Above and below 0.905g/cm ³ More preferably 0.862g/cm ³ The above and less than 0.900g/cm ³ Particularly preferably 0.864g/cm ³ The above and less than 0.895g/cm ³ . By making the density of the olefin elastomer satisfy the above range, the substrate is excellent in the following property of the irregularities when the semiconductor device as an adherend is attached to an adhesive sheet, and the like.

The mass ratio of the monomer containing an olefin compound (also referred to as "olefin content" in the present specification) of all the monomers used for forming the elastomer is preferably 50% by mass or more and 100% by mass or less.

When the olefin content is too low, the elastomer is unlikely to exhibit properties as an elastomer containing structural units derived from an olefin, and the base material is unlikely to exhibit flexibility and rubber elasticity.

From the viewpoint of stably obtaining flexibility and rubber elasticity, the olefin content is preferably 50 mass% or more, more preferably 60 mass% or more.

The styrene-based elastomer may be exemplified by: styrene-conjugated diene copolymers, styrene-olefin copolymers, and the like. Specific examples of the styrene-conjugated diene copolymer include: hydrogenated styrene-conjugated diene copolymers such as styrene-butadiene copolymers, styrene-butadiene-styrene copolymers (SBS), styrene-butadiene-butene-styrene copolymers, styrene-isoprene-styrene copolymers (SIS), unhydrogenated styrene-conjugated diene copolymers such as styrene-ethylene-isoprene-styrene copolymers, styrene-ethylene/propylene-styrene copolymers (SEPS, hydrogenated products of styrene-isoprene-styrene copolymers), and styrene-ethylene-butene-styrene copolymers (SEBS, hydrogenated products of styrene-butadiene copolymers). Further, as styrene-based elastomers industrially, there are listed: trade names such as Tufprene (manufactured by asahi chemical Co., ltd.), kraton (manufactured by Kraton Polymers Japan), sumitomo TPE-SB (manufactured by Sumitomo chemical Co., ltd.), EPOFIEND (manufactured by Satsubishi chemical Co., ltd.), rubberron (manufactured by kavali chemical Co., ltd.), septon (manufactured by colali Co., ltd.), and Tuftec (manufactured by asahi chemical Co., ltd.). The styrenic elastomer may be a hydrogenated product or may be unhydrogenated.

Examples of the rubber-based material include: natural rubber, synthetic Isoprene Rubber (IR), butadiene Rubber (BR), styrene-butadiene rubber (SBR), chloroprene Rubber (CR), nitrile rubber (NBR), butyl rubber (IIR), halogenated butyl rubber, acrylic rubber, urethane rubber, polysulfide rubber, and the like. One of these may be used alone, or two or more may be used in combination.

The 1 st base material 11 may be a laminated film obtained by laminating a film formed of a plurality of the above-described materials (for example, thermoplastic elastomer or rubber-based material). The 1 st substrate 11 may be a laminated film obtained by laminating a film made of the above-described material (for example, a thermoplastic elastomer or a rubber-based material) and another film.

The 1 st base material 11 may contain an additive in a film containing the above-mentioned resin material as a main material. Specific examples of the additives are the same as those listed in the description of the 1 st substrate 11. Examples of the additive include: pigments, dyes, flame retardants, plasticizers, antistatic agents, lubricants, fillers, and the like. Examples of pigments include: titanium dioxide, carbon black, and the like. Examples of the filler include an organic material such as melamine resin, an inorganic material such as fumed silica, and a metal material such as nickel particles. The content of the additive optionally contained in the film is not particularly limited, and preferably falls within a range that enables the 1 st substrate 11 to exert a desired function.

The 1 st substrate 11 may be subjected to a treatment for improving adhesion with the 1 st adhesive layer 12 laminated on the surface of the 1 st substrate 11 on one or both surfaces of the 1 st substrate 11.

When the 1 st adhesive layer 12 contains an energy ray-curable adhesive, the 1 st base material 11 preferably has a transmittance to energy rays. When ultraviolet rays are used as the energy rays, the 1 st substrate 11 is preferably transparent to ultraviolet rays. In the case of using an electron beam as an energy ray, the 1 st substrate 11 preferably has electron beam transmittance.

The thickness of the 1 st base material 11 is not limited as long as the 1 st sheet 10 can function properly in a desired step. The thickness of the 1 st substrate 11 is preferably 20 μm or more, more preferably 40 μm or more. The thickness of the 1 st substrate 11 is preferably 250 μm or less, more preferably 200 μm or less.

When the thickness of the 1 st substrate 11 is measured at a plurality of positions at 2cm intervals in the in-plane direction on the 1 st substrate surface or the 1 st substrate back surface, the standard deviation of the thickness of the 1 st substrate 11 is preferably 2 μm or less, more preferably 1.5 μm or less, and still more preferably 1 μm or less. By setting the standard deviation to 2 μm or less, the 1 st sheet 10 has a high-precision thickness, and the 1 st sheet 10 can be uniformly stretched.

The 1 st substrate 11 has tensile elastic moduli in the MD and CD directions of 10MPa to 350MPa, respectively, at 23 ℃, and 100% stresses in the MD and CD directions of the 1 st substrate 11 are 3MPa to 20MPa, respectively, at 23 ℃.

By setting the tensile elastic modulus and 100% stress to the above ranges, the 1 st sheet 10 can be greatly stretched.

The 100% stress of the 1 st substrate 11 is a value obtained in the following manner. A test piece having a size of 150mm (longitudinal direction). Times.15 mm (width direction) was cut from the 1 st substrate 11. The both ends of the cut test piece in the longitudinal direction were clamped with a jig so that the length between the jigs was 100mm. After the test piece was clamped by the jigs, the test piece was pulled in the longitudinal direction at a speed of 200 mm/min, and the measured value of the tensile force when the length between the jigs reached 200mm was read. The 100% stress of the 1 st substrate 11 is a value obtained by dividing the measured value of the tensile force read by the cross-sectional area of the substrate. The cross-sectional area of the 1 st substrate 11 was calculated as the length in the width direction of 15mm×the thickness of the 1 st substrate 11 (test piece). The cutting was performed so that the direction of travel (MD direction) or the direction perpendicular to the MD direction (CD direction) at the time of substrate production was aligned with the longitudinal direction of the test piece. In the tensile test, the thickness of the test piece is not particularly limited, and may be the same as the thickness of the base material to be tested.

The elongation at break in the MD and CD directions of the 1 st substrate 11 at 23℃is preferably 100% or more, respectively.

By setting the elongation at break in the MD direction and the CD direction of the 1 st base material 11 to 100% or more, the 1 st sheet 10 can be greatly stretched without breaking.

The tensile modulus (MPa) of the substrate and the elongation at break (%) of the substrate can be measured as follows. The substrate was cut into 15mm×140mm pieces to obtain test pieces. The test piece was measured for elongation at break and tensile modulus at 23℃according to JIS K7161:2014 and JIS K7127:1999. Specifically, the test piece was subjected to a tensile test at a speed of 200 mm/min with a tensile tester (product name "Autograph AG-IS 500N") and the elongation at break (%) and tensile modulus (MPa) were measured. The measurement was performed in both the direction of travel (MD) and the direction perpendicular to the direction (CD) during the substrate production.

1 st adhesive layer

The 1 st pressure-sensitive adhesive layer 12 is not particularly limited as long as it can function properly in a desired step such as a dicing step. Examples of the binder contained in the 1 st binder layer 12 include: rubber-based adhesives, acrylic adhesives, silicone adhesives, polyester adhesives, and urethane adhesives.

Energy ray-curable resin (ax 1)

The 1 st adhesive layer 12 preferably contains an energy ray curable resin (ax 1). The energy ray curable resin (ax 1) has an energy ray curable double bond in a molecule.

The adhesive layer containing the energy ray-curable resin is cured by irradiation with energy rays, and the adhesive force is reduced. In the case where the adherend is to be separated from the adhesive sheet, the adherend can be easily separated by irradiation of energy rays to the adhesive layer.

The energy ray curable resin (ax 1) is preferably a (meth) acrylic resin.

The energy ray-curable resin (ax 1) is preferably an ultraviolet-curable resin, and more preferably an ultraviolet-curable (meth) acrylic resin.

The energy ray curable resin (ax 1) is a resin which undergoes polymerization curing when irradiated with energy rays. Examples of the energy ray include ultraviolet rays and electron beams.

Examples of the energy ray-curable resin (ax 1) include low molecular weight compounds having an energy ray-polymerizable group (monofunctional monomers, polyfunctional monomers, monofunctional oligomers, and polyfunctional oligomers). Specific examples of the energy ray-curable resin (a 1) include acrylates such as trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1, 4-butanediol diacrylate, and 1, 6-hexanediol diacrylate, acrylates containing a cyclic aliphatic skeleton such as dicyclopentadiene dimethoxy diacrylate and isobornyl acrylate, and acrylic compounds such as polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy modified acrylate, polyether acrylate, and itaconic acid oligomer. The energy ray curable resin (a 1) may be used singly or in combination of two or more.

The molecular weight of the energy ray-curable resin (ax 1) is usually 100 to 30000, preferably 300 to 10000.

(meth) acrylic copolymer (b 1)

The 1 st adhesive layer 12 preferably further contains a (meth) acrylic copolymer (b 1). The (meth) acrylic copolymer is different from the energy ray curable resin (ax 1) described above.

The (meth) acrylic copolymer (b 1) preferably has an energy ray-curable carbon-carbon double bond. That is, in the present embodiment, the 1 st adhesive layer 12 preferably contains an energy ray curable resin (ax 1) and an energy ray curable (meth) acrylic copolymer (b 1).

The 1 st pressure-sensitive adhesive layer 12 preferably contains the energy ray-curable resin (ax 1) in an amount of 10 parts by weight or more, more preferably 20 parts by weight or more, and still more preferably 25 parts by weight or more, based on 100 parts by weight of the (meth) acrylic copolymer (b 1).

The 1 st pressure-sensitive adhesive layer 12 preferably contains the energy ray-curable resin (ax 1) in an amount of 80 parts by weight or less, more preferably 70 parts by weight or less, and still more preferably 60 parts by weight or less, based on 100 parts by weight of the (meth) acrylic copolymer (b 1).

The weight average molecular weight (Mw) of the (meth) acrylic copolymer (b 1) is preferably 1 ten thousand or more, more preferably 15 ten thousand or more, and still more preferably 20 ten thousand or more.

The weight average molecular weight (Mw) of the (meth) acrylic copolymer (b 1) is preferably 150 ten thousand or less, more preferably 100 ten thousand or less.

The weight average molecular weight (Mw) in the present specification is a value converted to standard polystyrene as measured by Gel Permeation Chromatography (GPC).

The (meth) acrylic copolymer (b 1) is preferably a (meth) acrylate polymer (b 2) having a functional group having energy ray curability (energy ray curable group) introduced into a side chain thereof (hereinafter, sometimes referred to as "energy ray curable polymer (b 2)").

Energy ray-curable polymer (b 2)

The energy ray-curable polymer (b 2) is preferably a copolymer obtained by reacting an acrylic copolymer (b 21) having a functional group-containing monomer unit with an unsaturated group-containing compound (b 22) having a functional group bonded to the functional group.

In the present specification, (meth) acrylate means both acrylate and methacrylate. Other similar terms are also used.

The acrylic copolymer (b 21) preferably contains structural units derived from a functional group-containing monomer, and structural units derived from a (meth) acrylate monomer or a (meth) acrylate monomer derivative.

The functional group-containing monomer as the structural unit of the acrylic copolymer (b 21) is preferably a monomer having a polymerizable double bond in the molecule and a functional group. The functional group is preferably at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, an epoxy group, and the like.

Examples of the hydroxyl group-containing monomer include: 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like. The hydroxyl group-containing monomers may be used singly or in combination of two or more.

Examples of the carboxyl group-containing monomer 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 may be used singly or in combination of two or more.

Examples of the amino group-containing monomer or the substituted amino group-containing monomer include: aminoethyl (meth) acrylate, n-butylaminoethyl (meth) acrylate, and the like. The amino group-containing monomer or the substituted amino group-containing monomer may be used singly or in combination of two or more.

As the (meth) acrylic acid ester monomer constituting the acrylic copolymer (b 21), in addition to the alkyl (meth) acrylate having 1 to 20 carbon atoms in the alkyl group, for example, a monomer having an alicyclic structure in the molecule (alicyclic structure-containing monomer) can be preferably used.

The alkyl (meth) acrylate is preferably one having 1 to 18 carbon atoms in the alkyl group. The alkyl (meth) acrylate is more preferably, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, or the like. The alkyl (meth) acrylate may be used singly or in combination of two or more.

As the alicyclic structure-containing monomer, for example, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like can be preferably used. The alicyclic structure-containing monomer may be used singly or in combination of two or more.

The acrylic copolymer (b 21) preferably contains the structural unit derived from the functional group-containing monomer in an amount of 1% by mass or more, more preferably contains the structural unit derived from the functional group-containing monomer in an amount of 5% by mass or more, and still more preferably contains the structural unit derived from the functional group-containing monomer in an amount of 10% by mass or more.

The acrylic copolymer (b 21) preferably contains a structural unit derived from the functional group-containing monomer at a ratio of 35% by mass or less, more preferably contains a structural unit derived from the functional group-containing monomer at a ratio of 30% by mass or less, and still more preferably contains a structural unit derived from the functional group-containing monomer at a ratio of 25% by mass or less.

The acrylic copolymer (b 21) preferably contains a structural unit derived from a (meth) acrylate monomer or a derivative thereof in an amount of 50% by mass or more, more preferably contains a structural unit derived from a (meth) acrylate monomer or a derivative thereof in an amount of 60% by mass or more, and still more preferably contains a structural unit derived from a (meth) acrylate monomer or a derivative thereof in an amount of 70% by mass or more.

The acrylic copolymer (b 21) preferably contains a structural unit derived from a (meth) acrylate monomer or a derivative thereof in an amount of 99 mass% or less, more preferably contains a structural unit derived from a (meth) acrylate monomer or a derivative thereof in an amount of 95 mass% or less, and still more preferably contains a structural unit derived from a (meth) acrylate monomer or a derivative thereof in an amount of 90 mass% or less.

The acrylic copolymer (b 21) can be obtained by copolymerizing the functional group-containing monomer described above with a (meth) acrylate monomer or a derivative thereof by a usual method.

The acrylic copolymer (b 21) may contain, in addition to the above-mentioned monomers, at least one structural unit selected from the group consisting of dimethylacrylamide, vinyl formate, vinyl acetate, styrene, and the like.

The energy ray-curable polymer (b 2) can be obtained by reacting the acrylic copolymer (b 21) having the functional group-containing monomer unit with the unsaturated group-containing compound (b 22) having a functional group bonded to the functional group thereof.

The functional group of the unsaturated group-containing compound (b 22) may be appropriately selected depending on the kind of the functional group-containing monomer unit of the acrylic copolymer (b 21). For example, in the case where the functional group of the acrylic copolymer (b 21) is a hydroxyl group, an amino group or a substituted amino group, the functional group of the unsaturated group-containing compound (b 22) is preferably an isocyanate group or an epoxy group, and in the case where the functional group of the acrylic copolymer (b 21) is an epoxy group, the functional group of the unsaturated group-containing compound (b 22) is preferably an amino group, a carboxyl group or an aziridine group.

The unsaturated group-containing compound (b 22) contains at least 1 energy-ray polymerizable carbon-carbon double bond in 1 molecule, preferably contains 1 or more and 6 or less, more preferably contains 1 or more and 4 or less energy-ray polymerizable carbon-carbon double bonds.

Examples of the unsaturated group-containing compound (b 22) include: 2-methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate), m-isopropenyl- α, α -dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1- (bisacryloxymethyl) ethyl isocyanate; an acryl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth) acrylate; an acryl monoisocyanate compound obtained by the reaction of a diisocyanate compound or polyisocyanate compound, a 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->Oxazolines, and the like.

The unsaturated group-containing compound (b 22) is preferably used in a proportion of 50 mol% or more (addition ratio), more preferably 60 mol% or more, and still more preferably 70 mol% or more, based on the number of moles of the functional group-containing monomer of the acrylic copolymer (b 21).

The unsaturated group-containing compound (b 22) is preferably used in an amount of 95 mol% or less, more preferably 93 mol% or less, and still more preferably 90 mol% or less, based on the number of moles of the functional group-containing monomer of the acrylic copolymer (b 21).

In the reaction of the acrylic copolymer (b 21) and the unsaturated group-containing compound (b 22), the temperature, pressure, solvent, time, presence or absence of a catalyst, and the kind of catalyst may be appropriately selected according to the combination of the functional group of the acrylic copolymer (b 21) and the functional group of the unsaturated group-containing compound (b 22). Thus, the functional group of the acrylic copolymer (b 21) reacts with the functional group of the unsaturated group-containing compound (b 22), and an unsaturated group is introduced into the side chain of the acrylic copolymer (b 21), thereby obtaining the energy ray-curable polymer (b 2).

The weight average molecular weight (Mw) of the energy ray-curable polymer (b 2) is preferably 1 ten thousand or more, more preferably 15 ten thousand or more, and still more preferably 20 ten thousand or more.

The weight average molecular weight (Mw) of the energy ray-curable polymer (b 2) is preferably 150 ten thousand or less, more preferably 100 ten thousand or less.

Photopolymerization initiator (C)

In the case where the 1 st adhesive layer 12 contains an ultraviolet-curable compound (for example, an ultraviolet-curable resin), the 1 st adhesive layer 12 preferably contains a photopolymerization initiator (C).

By containing the photopolymerization initiator (C) in the 1 st adhesive layer 12, the polymerization curing time and the light irradiation amount can be reduced.

Specific examples of the photopolymerization initiator (C) include, for example: benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds and peroxide compounds. Examples of the photopolymerization initiator (C) include: photosensitizers such as amines and quinones.

More specific photopolymerization initiator (C) includes, for example: 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl phenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, butanedione, 8-chloroanthraquinone, and bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide. The photopolymerization initiator (C) may be used singly or in combination of two or more.

The amount of the photopolymerization initiator (C) to be blended is preferably 0.01 to 10 parts by weight, more preferably 0.03 to 5 parts by weight, still more preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the adhesive resin.

When the energy ray-curable resin (ax 1) and the (meth) acrylic copolymer (b 1) are blended in the pressure-sensitive adhesive layer, the photopolymerization initiator (C) is preferably used in an amount of 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, relative to 100 parts by mass of the total amount of the energy ray-curable resin (ax 1) and the (meth) acrylic copolymer (b 1).

In the case where the energy ray-curable resin (ax 1) and the (meth) acrylic copolymer (b 1) are blended in the pressure-sensitive adhesive layer, the photopolymerization initiator (C) is preferably used in an amount of 10 parts by mass or less, more preferably 6 parts by mass or less, based on 100 parts by mass of the total amount of the energy ray-curable resin (ax 1) and the (meth) acrylic copolymer (b 1).

The 1 st pressure-sensitive adhesive layer 12 may be appropriately blended with other components in addition to the above components. Examples of the other component include a crosslinking agent (E).

Crosslinking agent (E)

As the crosslinking agent (E), a polyfunctional compound reactive with the functional group of the (meth) acrylic copolymer (b 1) or the like can be used. Examples of the polyfunctional compound in the 1 st sheet 10 include: isocyanate compound, epoxy compound, amine compound, melamine compound, aziridine compound, hydrazine compound, aldehyde compound, Oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, reactive phenolic resins, and the like.

The amount of the crosslinking agent (E) to be blended 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 or more, based on 100 parts by mass of the (meth) acrylic copolymer (b 1).

The amount of the crosslinking agent (E) to be blended 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 or less, based on 100 parts by mass of the (meth) acrylic copolymer (b 1).

The thickness of the 1 st adhesive layer 12 is not particularly limited. The thickness of the 1 st pressure-sensitive adhesive layer 12 is, for example, preferably 10 μm or more, more preferably 20 μm or more. The thickness of the 1 st pressure-sensitive adhesive layer 12 is preferably 150 μm or less, more preferably 100 μm or less.

The recovery rate of the 1 st sheet 10 is preferably 70% or more, more preferably 80% or more, and still more preferably 85% or more. The recovery rate of the 1 st sheet 10 is preferably 100% or less. By setting the recovery ratio to the above range, the pressure-sensitive adhesive sheet can be greatly stretched.

The recovery rate is obtained by: for a test piece in which an adhesive sheet was cut into 150mm (longitudinal direction) ×15mm (width direction), both ends in the longitudinal direction were clamped by clamps, the length between the clamps was set to 100mm, then the test piece was stretched at a speed of 200 mm/min until the length between the clamps reached 200mm, the test piece was held for 1 minute in a state in which the length between the clamps was expanded to 200mm, then the test piece was recovered at a speed of 200 mm/min to the length between the clamps for 1 minute in a state in which the length between the clamps was recovered to 100mm, then the test piece was stretched at a speed of 60 mm/min in the longitudinal direction, the measured value of the tensile force was measured to show the length between the clamps at 0.1N/15mm, the length obtained by subtracting the initial length between the clamps by 100mm was set to L2 (mm), and the length obtained by subtracting the initial length between the clamps by 100mm from the length between the clamps in the expanded state was set to L1 (mm), the test piece was calculated by the following formula (mathematical formula 2).

Recovery (%) = {1- (L2L 1) } ×100. Cndot. Of formula 2

When the recovery ratio is within the above range, the adhesive sheet is easily recovered even after being stretched to a large extent. In general, when a sheet having a yield point is stretched to a temperature equal to or higher than the yield point, the sheet is plastically deformed, and a portion subjected to plastic deformation, that is, a portion subjected to extreme stretching is in a state where unevenness exists. When the sheet in such a state is further stretched, the sheet is broken from the extremely stretched portion, or the spread sheet becomes uneven even if the sheet is not broken. In the stress-strain graph plotted on the x-axis and the y-axis of the strain and elongation, even if the slope dx/dy does not take a stress value ranging from a positive value to 0 or a negative value and does not show a clear yield point, the sheet is plastically deformed with an increase in the tensile amount, and breakage is caused or the spread sheet becomes uneven. On the other hand, when elastic deformation occurs, not plastic deformation, the sheet is easily restored to its original shape by releasing the stress. Therefore, by setting the recovery rate, which is an index indicating how much the adhesive sheet recovers after being stretched by a sufficiently large amount, that is, 100%, in the above range, plastic deformation of the film when the adhesive sheet is stretched greatly can be suppressed to the minimum, and it is possible to realize a uniform sheet with less breakage.

(Release sheet)

A release sheet is attached to the surface of the 1 st sheet 10. Specifically, the release sheet is adhered to the surface of the 1 st adhesive layer 12 of the 1 st sheet 10. The release sheet is adhered to the surface of the 1 st adhesive layer 12 to protect the 1 st adhesive layer 12 during transportation and storage. The release sheet is releasably adhered to the 1 st sheet 10 and is peeled from the 1 st sheet 10 for removal prior to use of the 1 st sheet 10.

The release sheet may be one having at least one surface subjected to a release treatment. Specifically, examples thereof include: the release sheet comprises a release sheet substrate and a release agent layer formed by coating a release agent on the surface of the substrate.

As the base material for the release sheet, a resin film is preferable. Examples of the resin constituting the resin film as the base material for the release sheet include: polyethylene terephthalate resin, polybutylene terephthalate resin, polyester resin films such as polyethylene naphthalate resin, and polyolefin resins such as polypropylene resin and polyethylene resin.

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

The thickness of the release sheet is not particularly limited, but is preferably 10 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less.

(method for producing adhesive sheet)

The method for producing the pressure-sensitive adhesive sheet described in the 1 st sheet 10 and other descriptions herein is not particularly limited, and the pressure-sensitive adhesive sheet can be produced by a known method.

For example, an adhesive layer provided on a release sheet may be bonded to one surface of a base material, and an adhesive sheet having a release sheet attached to the surface of the adhesive layer may be produced. Further, a laminate of the buffer layer and the substrate can be obtained by bonding the buffer layer provided on the release sheet to the substrate and removing the release sheet. Then, the pressure-sensitive adhesive layer provided on the release sheet is bonded to the base material side of the laminate, whereby a pressure-sensitive adhesive sheet having the release sheet bonded to the surface of the pressure-sensitive adhesive layer can be produced. In the case where the buffer layers are provided on both sides of the base material, the adhesive layer is formed on the buffer layers. The release sheet attached to the surface of the pressure-sensitive adhesive layer may be removed by being suitably peeled off before the pressure-sensitive adhesive sheet is used.

As a more specific example of the method for producing the pressure-sensitive adhesive sheet, the following method can be given. First, a coating liquid containing an adhesive composition constituting the adhesive layer and a solvent or a dispersion medium further added as needed is prepared. Then, the coating liquid is applied to one surface of the substrate by a coating mechanism to form a coating film. Examples of the coating means include: die coater, curtain coater, spray coater, slot coater, knife coater, and the like. Next, by drying the coating film, an adhesive layer can be formed. The properties of the coating liquid are not particularly limited as long as the coating liquid can be applied. The coating liquid includes both a case of containing a component for forming the adhesive layer as a solute and a case of containing a component for forming the adhesive layer as a dispersoid. Similarly, the pressure-sensitive adhesive layer may be formed by directly applying the pressure-sensitive adhesive composition to one surface of the substrate or the buffer layer.

In addition, as another more specific example of the method for producing the pressure-sensitive adhesive sheet, the following method can be mentioned. First, a coating liquid is applied to the release surface of the release sheet to form a coating film. Subsequently, the coating film is dried to form a laminate composed of the pressure-sensitive adhesive layer and the release sheet. Next, a base material may be attached to the surface of the pressure-sensitive adhesive layer of the laminate opposite to the surface of the release sheet side, thereby obtaining a laminate of the pressure-sensitive adhesive sheet and the release sheet. The release sheet in the laminate may be peeled as a process material, or may be used to protect the adhesive layer until an adherend (for example, a semiconductor chip, a semiconductor wafer, or the like) is stuck to the adhesive layer.

When the coating liquid contains a crosslinking agent, for example, the crosslinking reaction between the (meth) acrylic copolymer in the coating film and the crosslinking agent can be performed by changing the drying condition (for example, temperature, time, etc.) of the coating film or by performing a separate heat treatment, so that a crosslinked structure is formed in the adhesive layer at a desired existing density. In order to sufficiently carry out the crosslinking reaction, the pressure-sensitive adhesive layer may be laminated on the substrate by the above-mentioned method or the like, and then the resulting pressure-sensitive adhesive sheet may be left to stand for several days in an environment of, for example, 23 ℃ and 50% relative humidity.

The thickness of the 1 st sheet 10 is preferably 30 μm or more, more preferably 50 μm or more. The thickness of the 1 st sheet 10 is preferably 400 μm or less, more preferably 300 μm or less.

(2 nd adhesive sheet)

The 2 nd pressure-sensitive adhesive sheet 20 of the present embodiment has a 2 nd base material 21 and a 2 nd pressure-sensitive adhesive layer 22. The 2 nd adhesive layer 22 is laminated on the 2 nd base material 21.

2 nd substrate

The constituent material of the 2 nd base material 21 of the present embodiment is not particularly limited as long as it can function properly in a desired step such as a dicing step.

The 2 nd base material 21 is preferably composed of a film mainly composed of a resin-based material. Examples of the film containing a resin-based material as a main material include: olefinic copolymer film, polyolefin film, polyvinyl chloride film, polyester film, polyurethane film, polyimide film, polystyrene film, polycarbonate film, and fluororesin film.

Adhesive layer 2

The constituent material of the 2 nd pressure-sensitive adhesive layer 22 is not particularly limited as long as it can function properly in a desired step such as a dicing step.

The 2 nd adhesive layer 22 is preferably formed of at least one adhesive selected from the group consisting of an acrylic adhesive, a urethane adhesive, a polyester adhesive, a rubber adhesive, and a silicone adhesive, and more preferably formed of an acrylic adhesive.

The 2 nd adhesive layer 22 may be formed of a non-energy ray curable adhesive or an energy ray curable adhesive.

[ Effect of the present embodiment ]

According to the dicing method of the present embodiment, when the 1 st sheet 10 is stretched, the circuit surface W1 of the semiconductor chip CP is not joined to the 1 st adhesive layer 12 of the 1 st sheet 10. Since the individual semiconductor chips CP sandwich the protective layer 100 that has been singulated in the dicing step between the circuit surface W1 and the 1 st adhesive layer 12, the protective layer 100 that has been brought into contact with the circuit surface W1 is not stretched even when the 1 st sheet 10 is stretched. As a result, according to the dicing method of the present embodiment, the residual glue can be suppressed.

The pressure-sensitive adhesive sheet used in the sheet expanding method of the present embodiment has a simple structure including a base material and a pressure-sensitive adhesive layer. In addition, since the adhesive sheet used in the dicing step is transferred from the adhesive sheet used in the dicing step to the adhesive sheet used in the dicing step before the dicing step is performed, the depth of the dicing mark does not need to be carefully controlled so that the dicing blade does not reach the base material of the dicing sheet in the dicing step.

Therefore, according to the sheet expanding method of the present embodiment, the adhesive sheet structure and process can be simplified and the residual glue can be suppressed as compared with the conventional one.

Further, a method for manufacturing a semiconductor device including the dicing method of the present embodiment can be provided.

[ embodiment 2 ]

Next, embodiment 2 of the present invention will be described.

Embodiment 1 and embodiment 2 differ mainly in the following points. In embodiment 1, a protective layer is provided on the 1 st object surface (circuit surface W1) of the object (semiconductor wafer W), whereas in embodiment 2, the 2 nd object surface (back surface W3) of the object (semiconductor wafer W) is bonded to the protective layer of the composite sheet having the protective layer and the 3 rd sheet, whereby the protective layer is provided on the object.

In the following description, a description will be mainly given of portions different from embodiment 1, and the repeated description will be omitted or simplified. The same reference numerals are given to the same components as those of embodiment 1, and the description thereof will be omitted or simplified.

Fig. 6 (fig. 6A, 6B, and 6C) and fig. 7 (fig. 7A, 7B, and 7C) are schematic cross-sectional views illustrating a method for manufacturing a semiconductor device including the dicing method of the present embodiment.

The sheet expanding method according to the present embodiment includes the following steps (PX 1) to (PX 5).

(PX 1) bonding the object to the protective layer having the composite sheet of the protective layer and the 3 rd sheet.

(PX 2) cutting the wafer from the object plane side of the 1 st object, and cutting at least the protective layer to singulate the plurality of semiconductor devices. The 1 st object plane becomes a circuit plane of the semiconductor device, and the 2 nd object plane becomes a back plane of the semiconductor device.

(PX 3) peeling the 3 rd sheet in a state where the protective layer remains on the back surface of the semiconductor device.

(PX 4) a step of adhering the 1 st sheet to the protective layer on the back surface side of the semiconductor device.

(PX 5) a step of expanding the 1 st sheet to expand the intervals between the plurality of semiconductor devices.

(composite sheet)

Fig. 6A shows a schematic cross-sectional view of the composite sheet 130 used in the present embodiment.

The composite sheet 130 has a protective layer 100A and a 3 rd sheet 30. The composite sheet 130 holds the semiconductor wafer W while dicing the semiconductor wafer W. The semiconductor wafer W is bonded to the protective layer 100A of the composite sheet 130 with the back surface W3.

(protective layer)

The protective layer 100A in the composite sheet 130 is laminated on the 3 rd sheet 30. The protective layer 100A is not particularly limited as long as it can be bonded to the back surface W3 of the semiconductor wafer W as the object to be processed and the semiconductor chip CP as the semiconductor device (back surface of the semiconductor device) and protects the back surface W3. As the protective layer 100A, for example, there can be mentioned: a protective film, and a protective sheet. The thickness of the protective layer 100A is preferably 1 μm or more, more preferably 5 μm or more. The thickness of the protective layer 100A is preferably 500 μm or less, more preferably 300 μm or less.

As the protective layer 100A, for example, the same protective layer as the protective layer 100 described in embodiment 1 can be used.

(sheet 3)

The 3 rd sheet 30 of the composite sheet 130 is a member supporting the protective layer 100A. The 3 rd sheet 30 is not particularly limited as long as it can support the protective layer 100A. In the step (PX 3) of the present embodiment, the 3 rd sheet 30 is peeled off while the protective layer 100A remains on the back surface W3 of the semiconductor chip CP, and therefore, the 3 rd sheet 30 is preferably formed of a material or the like that can be peeled off from the protective layer 100A.

A more detailed example of the composite sheet 130 will be described later.

[ lamination Process of composite sheet ]

Fig. 6B is a diagram for explaining the step (PX 1). Fig. 6B illustrates the semiconductor wafer W to which the composite sheet 130 is bonded. The semiconductor wafer W in the present embodiment is also preferably a wafer obtained by a back grinding process. This step (PX 1) may be referred to as a lamination step of the composite sheet.

As described later, in the step (PX 2), the semiconductor wafer W is diced and singulated into a plurality of semiconductor chips CP. In the present embodiment, the composite sheet 130 is bonded to the back surface W3 in order to hold the semiconductor wafer W when dicing the semiconductor wafer W. The semiconductor wafer W is bonded to the protective layer 100 of the composite sheet 130 with the back surface W3.

In the present embodiment, the process is described by taking an example of a state where the circuit surface W1 is exposed, and examples of other modes include, for example: the process is performed in a state where a protective member such as a protective sheet or a protective film different from the protective layer 100A is attached to the circuit surface W1.

[ cutting procedure ]

Fig. 6C is a diagram for explaining the step (PX 2). The step (PX 2) is sometimes referred to as a dicing step. Fig. 6C shows a plurality of semiconductor chips CP held by the composite sheet 130.

The semiconductor wafer W having the composite sheet 130 bonded to the back surface W3 is diced and singulated to form a plurality of semiconductor chips CP. The circuit surface W1 as the 1 st semiconductor device surface corresponds to the circuit surface of the chip. The back surface W3 as the 2 nd semiconductor device surface corresponds to the back surface of the chip.

In the present embodiment, the semiconductor wafer W is cut by cutting a dicing mark from the circuit surface W1 side, and at least the protective layer 100A of the composite sheet 130 is cut.

The dicing depth at the dicing is not particularly limited as long as the semiconductor wafer W and the protective layer 100A can be singulated. In the present embodiment, the case where the 3 rd sheet 30 is not cut by the dicing lines has been described as an example, but the present invention is not limited to this embodiment. For example, in another embodiment, from the viewpoint of reliably cutting the semiconductor wafer W and the protective layer 100A, a scribe line may be formed by dicing to a depth reaching the 3 rd sheet 30.

[ step of peeling off the 3 rd sheet ]

Fig. 7A is a diagram for explaining the step (PX 3). The step (PX 3) may be referred to as a sheet 3 peeling step. Fig. 7A shows a step of peeling the 3 rd sheet 30 in a state where the protective layer 100A remains on the rear surface W3 of the singulated semiconductor chip CP after the dicing step.

In the case where the protective layer 100A is directly laminated on the 3 rd sheet 30 as one embodiment of the composite sheet 130, the protective layer 100A is preferably peeled off from the 3 rd sheet 30 at the interface in the 3 rd sheet peeling step. After the 3 rd sheet 30 is peeled off, a plurality of semiconductor chips CP having the protective layer 100A attached to the back surface W3 can be obtained.

The peeling force at the time of peeling the 3 rd sheet 30 from the protective layer 100A is preferably 10mN/25mm or more and 2000mN/25mm or less. When the peeling force of the 3 rd sheet 30 from the protective layer 100A is 10mN/25mm or more, the effect of excellent semiconductor chip retention at dicing can be obtained. When the peeling force at the time of peeling the 3 rd sheet 30 from the protective layer 100A is 2000mN/25mm or less, an effect of excellent pickup of the semiconductor chip after dicing can be obtained. The peeling force at the time of peeling the 3 rd sheet 30 from the protective layer 100A is preferably 30mN/25mm or more and 1000mN/25mm or less, more preferably 50mN/25mm or more and 500mN/25mm or less.

[ bonding step of sheet 1 ]

Fig. 7B is a diagram for explaining the step (PX 4). The step (PX 4) may be referred to as a bonding step of the 1 st sheet. Fig. 7B shows a state in which the 1 st sheet 10 is attached to a plurality of semiconductor chips CP obtained by the dicing process. The 1 st sheet 10 of the present embodiment is the same as the 1 st sheet 10 used in embodiment 1.

In the present embodiment, when the 1 st sheet 10 is adhered to the back surface W3 side of the plurality of semiconductor chips CP, a laminated structure is obtained in which the plurality of semiconductor chips CP and the 1 st adhesive layer 12 of the 1 st sheet 10 are sandwiched by the singulated protective layers 100A.

[ step of expanding sheet ]

Fig. 7C is a diagram for explaining the step (PX 5). The process (PX 5) is sometimes referred to as a dicing step. Fig. 7C shows a state in which the 1 st sheet 10 is stretched after the 1 st sheet 10 is attached, and the intervals between the plurality of semiconductor chips CP are enlarged.

In the sheet expanding step of the present embodiment, the method of stretching the 1 st sheet 10 is similar to that of embodiment 1. In the present embodiment, the interval D1 of the plurality of semiconductor chips CP is also not particularly limited as depending on the size of the semiconductor chips CP. The distance D1 between adjacent semiconductor chips CP is preferably 200 μm or more. The upper limit of the interval between the semiconductor chips CP is not particularly limited. The upper limit of the interval between the semiconductor chips CP may be 6000 μm, for example.

[ transfer Process 1 ]

In the present embodiment, after the dicing step, a step of bonding the plurality of semiconductor chips CP bonded to the 1 st sheet 10 to the 6 th adhesive sheet 60 (hereinafter, sometimes referred to as "1 st transfer step") may be performed in the same manner as in the 1 st embodiment.

In the case of performing the transfer step in the present embodiment, for example, after the dicing step, it is preferable to attach the 6 th adhesive sheet 60 to the circuit surface W1 of the plurality of semiconductor chips CP, and then peel the 1 st sheet 10 and the protective layer 100A from the back surface W3. The 1 st sheet 10 and the protective layer 100A may be peeled off from the back surface W3 together, or the protective layer 100A may be peeled off from the back surface W3 after the 1 st sheet 10 is peeled off. The step of peeling the protective layer 100A from the rear surface W3 is sometimes referred to as a protective layer peeling step.

The spacing D1 between the plurality of semiconductor chips CP expanded in the dicing step is preferably maintained even after the peeling step of the protective layer 100A.

When the protective layer 100A is peeled off from the back surface W3, the protective layer 100A preferably contains the 1 st energy ray curable resin from the viewpoint of suppressing the residual glue on the back surface W3. When the protective layer 100A contains the 1 st energy ray-curable resin, the 1 st energy ray-curable resin is cured by irradiation of the protective layer 100A with energy rays. When the 1 st energy ray-curable resin is cured, the cohesive force of the protective layer 100A can be increased, and the adhesive force between the protective layer 100A and the back surface W3 of the semiconductor chip CP can be reduced or eliminated. Examples of the energy rays include ultraviolet rays (UV) and Electron Beams (EB), and ultraviolet rays are preferable. Therefore, the 1 st energy ray curable resin is preferably an ultraviolet ray curable resin.

In the case where the 1 st sheet 10 is provided with the 1 st adhesive layer 12, the 1 st adhesive layer 12 preferably contains the 2 nd energy ray-curable resin, from the viewpoint of peeling the 1 st sheet 10 together with the protective layer 100A from the back surface W3. When the protective layer 100A contains the 1 st energy ray-curable resin and the 1 st adhesive layer 12 contains the 2 nd energy ray-curable resin, the 1 st adhesive layer 12 and the protective layer 100A are irradiated with energy rays from the 1 st base material 11 side to cure the 2 nd energy ray-curable resin and the 1 st energy ray-curable resin. Examples of the energy ray used to cure the 2 nd energy ray curable resin include Ultraviolet (UV) and Electron Beam (EB), and ultraviolet rays are preferable. Therefore, the 2 nd energy ray curable resin is preferably an ultraviolet ray curable resin. The 1 st substrate 11 preferably has energy ray permeability.

As an embodiment different from the present embodiment, the protective layer 100A may be used as a protective film for protecting the back surface W3 of the semiconductor chip CP, instead of being peeled off from the back surface W3 of the semiconductor chip CP. When the protective layer 100A is used as the protective film for the rear surface W3, the protective layer 100A preferably contains a curable adhesive composition.

[ sealing Process and other Process ]

In this embodiment, the sealing step and other steps (the rewiring layer forming step and the step of connecting to the external terminal electrode) may be performed in the same manner as in embodiment 1.

(composite sheet)

In one embodiment of the present embodiment, the protective layer 100A of the composite sheet 130 is preferably a 3 rd pressure-sensitive adhesive layer, and the 3 rd sheet 30 is preferably a 3 rd base material. That is, the composite sheet 130 is preferably an adhesive sheet having a 3 rd base material and a 3 rd adhesive layer and being peelable between the 3 rd base material and the 3 rd adhesive layer.

3 rd substrate

The 3 rd base material of the present embodiment is not particularly limited as long as it can function properly in a desired process. The 3 rd substrate is a member supporting the 3 rd adhesive layer.

The 3 rd base material is, for example, a resin film. As the resin film, at least any film selected from the group consisting of: for example, polyethylene films, polypropylene films, polybutylene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films, polyethylene naphthalate films, polybutylene terephthalate films, polyurethane films, ethylene-vinyl acetate copolymer films, ionomer resin films, ethylene- (meth) acrylic acid copolymer films, ethylene- (meth) acrylic acid ester copolymer films, polystyrene films, polycarbonate films, polyimide films, and fluororesin films. As the 3 rd base material, a crosslinked film thereof may be used. The 3 rd substrate may be a laminated film of these films.

The 3 rd base material may be, for example, a hard support. The material of the hard support may be appropriately determined in consideration of mechanical strength, heat resistance, and the like. Examples of the material of the hard support include: metal materials such as SUS; nonmetallic inorganic materials such as glass and silicon wafers; resin materials such as epoxy, ABS, acrylic, engineering plastics, special engineering plastics, polyimide, and polyamideimide; among them, SUS, glass, silicon wafer, and the like are preferable. As engineering plastics, there may be mentioned: nylon, polycarbonate (PC), polyethylene terephthalate (PET), and the like. Specific engineering plastics include: polyphenylene Sulfide (PPS), polyethersulfone (PES), polyetheretherketone (PEEK), and the like.

The thickness of the 3 rd substrate is not particularly limited. The thickness of the 3 rd substrate is preferably 20 μm or more and 50mm or less, more preferably 60 μm or more and 20mm or less. When the thickness of the 3 rd base material is in the above range, the 3 rd sheet 30 has sufficient flexibility in the case where the 3 rd base material is a resin film, and therefore, good adhesion to the object (workpiece) is exhibited. The object to be processed is, for example, a wafer or a semiconductor element, and more specifically, a semiconductor wafer or a semiconductor chip. When the 3 rd base material is a hard support, the thickness of the hard support may be appropriately determined in consideration of mechanical strength, handleability, and the like. The thickness of the hard support is, for example, 100 μm or more and 50mm or less.

3 rd adhesive layer

The 3 rd pressure-sensitive adhesive layer is not particularly limited as long as it can function properly in a desired step.

In one embodiment of the 3 rd adhesive layer, the adhesive layer is preferably formed of at least one adhesive selected from, for example, an acrylic adhesive, a urethane adhesive, a polyester adhesive, a rubber adhesive, and a silicone adhesive, and more preferably formed of an acrylic adhesive.

In one embodiment of the 3 rd pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer preferably contains a curable pressure-sensitive adhesive composition that cures upon receiving energy from the outside. Examples of the energy supplied from the outside include: ultraviolet light, electron beam, heat, and the like. The 3 rd adhesive layer preferably contains at least one of an ultraviolet curable adhesive and a thermosetting adhesive. In the case where the 3 rd substrate has heat resistance, the pressure-sensitive adhesive layer is preferably a thermosetting pressure-sensitive adhesive layer containing a thermosetting pressure-sensitive adhesive, because occurrence of residual stress during thermosetting can be suppressed.

The 3 rd adhesive layer contains, for example, a first adhesive composition. The first adhesive composition contains an adhesive polymer component (A) and a curable component (B).

(A) Adhesive polymer component

In order to impart sufficient adhesiveness and film-forming property (sheet-forming property) to the 3 rd pressure-sensitive adhesive layer, the pressure-sensitive adhesive polymer component (a) may be used. As the binder polymer component (a), conventionally known acrylic polymers, polyester resins, urethane resins, acrylic urethane resins, silicone resins, rubber polymers, and the like can be used.

The weight average molecular weight (Mw) of the binder polymer component (A) is preferably 1 to 200 ten thousand, more preferably 10 to 120 ten thousand. In the present specification, the weight average molecular weight (Mw) is a value converted to standard polystyrene as measured by gel permeation chromatography (Gel Permeation Chromatography; GPC).

As the binder polymer component (a), an acrylic polymer can be preferably used. The glass transition temperature (Tg) of the acrylic polymer is preferably in the range of-60℃or more and 50℃or less, more preferably-50℃or more and 40℃or less, still more preferably-40℃or more and 30℃or less.

The monomer for forming the acrylic polymer may be a (meth) acrylate monomer or a derivative thereof. For example, alkyl (meth) acrylates having an alkyl group with 1 to 18 carbon atoms are exemplified, and specific examples thereof include: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like. Further, (meth) acrylic esters having a cyclic skeleton are exemplified, and specific examples thereof include: cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, imide (meth) acrylate, and the like. Further, as the monomer having a functional group, there may be mentioned: hydroxymethyl (meth) acrylate having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and the like; and glycidyl (meth) acrylate having an epoxy group. Among the acrylic polymers, an acrylic polymer containing a monomer having a hydroxyl group is preferable because of its good compatibility with the curable component (B) described later. The acrylic polymer may be copolymerized with at least one member selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, and styrene.

Further, as the adhesive polymer component (a), a thermoplastic resin for maintaining the flexibility of the film of the 3 rd adhesive layer after curing may be blended. Such thermoplastic resins preferably have a weight average molecular weight of 1000 to 10 ten thousand, more preferably 3000 to 8 ten thousand. The glass transition temperature of the thermoplastic resin is preferably from-30℃to 120℃and more preferably from-20℃to 120 ℃. Examples of the thermoplastic resin include: polyester resin, urethane resin, phenoxy resin, polybutene, polybutadiene, polystyrene, or the like. These thermoplastic resins may be used singly or in combination of two or more.

(B) Curable component

The curable component (B) may be at least any one of thermosetting components and energy ray curable components. As the curable component (B), a thermosetting component and an energy ray curable component can be used.

As the thermosetting component, a thermosetting resin and a thermosetting agent can be used. As the thermosetting resin, for example, epoxy resin is preferable.

As the epoxy resin, conventionally known epoxy resins can be used. Specific examples of the epoxy resin include: epoxy compounds having a double function or more in the molecule, such as a multifunctional epoxy resin, bisphenol a diglycidyl ether or a hydrogenated product thereof, an o-cresol novolac epoxy resin, a dicyclopentadiene type epoxy resin, a biphenyl type epoxy resin, a bisphenol a type epoxy resin, a bisphenol F type epoxy resin, and a phenylene skeleton type epoxy resin. These epoxy resins may be used singly or in combination of two or more.

In the 3 rd pressure-sensitive adhesive layer, the content of the thermosetting resin is preferably 1 part by weight or more and 1000 parts by weight or less, more preferably 10 parts by weight or more and 500 parts by weight or less, still more preferably 20 parts by weight or more and 200 parts by weight or less, based on 100 parts by weight of the pressure-sensitive adhesive polymer component (a). When the content of the thermosetting resin is 1 part by weight or more, the problem that sufficient adhesiveness cannot be obtained can be suppressed. When the content of the thermosetting resin is 1000 parts by weight or less, the peeling force of the 3 rd adhesive layer from the 3 rd base material can be prevented from becoming excessively high. If the peeling force is prevented from becoming excessively high, transfer failure of the 3 rd adhesive layer to the back surface W3 of the semiconductor chip CP can be prevented.

The thermosetting agent functions as a curing agent for a thermosetting resin, particularly an epoxy resin. As a preferable thermosetting agent, a compound having 2 or more functional groups capable of reacting with an epoxy group in 1 molecule is exemplified. Examples of the functional group capable of reacting with an epoxy group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an acid anhydride group. Among these functional groups, a phenolic hydroxyl group, an amino group, an acid anhydride group, and the like are preferable, and a phenolic hydroxyl group and an amino group are more preferable.

Specific examples of the phenolic curing agent include polyfunctional phenol resins, diphenols, novolak-type phenol resins, dicyclopentadiene-type phenol resins, xylOCK-type phenol resins, and aralkyl-type phenol resins. As a specific example of the amine curing agent, DICY (dicyandiamide) is mentioned. These thermosetting agents may be used singly or in combination of two or more.

The content of the thermosetting agent is preferably 0.1 part by weight or more and 500 parts by weight or less, more preferably 1 part by weight or more and 200 parts by weight or less, relative to 100 parts by weight of the thermosetting resin.

When the 3 rd adhesive layer contains a thermosetting component as the curable component (B), the 3 rd adhesive layer has thermosetting properties. In this case, the 3 rd pressure-sensitive adhesive layer can be cured by heating, but in the 1 st sheet 10 of the present embodiment, when the 3 rd base material has heat resistance, there is a problem that residual stress is less likely to occur in the base material when the 3 rd pressure-sensitive adhesive layer is thermally cured, and thus a problem arises.

As the energy ray-curable component, a low molecular compound (energy ray-polymerizable compound) containing an energy ray-polymerizable group and being polymerized and cured when irradiated with energy rays such as ultraviolet rays or electron beams can be used. Specific examples of such an energy ray-curable component include: trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, or 1, 4-butanediol diacrylate, 1, 6-hexanediol diacrylate, polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy modified acrylate, polyether acrylate, and itaconic acid oligomer. Such a compound has at least 1 polymerizable double bond in the molecule, and the weight average molecular weight is usually 100 to 30000, preferably 300 to 10000. The amount of the energy ray-polymerizable compound to be blended is preferably 1 part by weight or more and 1500 parts by weight or less, more preferably 10 parts by weight or more and 500 parts by weight or less, still more preferably 20 parts by weight or more and 200 parts by weight or less, relative to 100 parts by weight of the binder polymer component (a).

As the energy ray-curable component, an energy ray-curable polymer in which an energy ray-polymerizable group is bonded to the main chain or side chain of the binder polymer component (a) can be used. Such an energy ray-curable polymer has both the function as the binder polymer component (a) and the function as the curable component (B).

The main skeleton of the energy ray-curable polymer is not particularly limited, and may be an acrylic polymer commonly used as the binder polymer component (a), or may be polyester, polyether, or the like, but from the viewpoint of easy control of synthesis and physical properties, an acrylic polymer is preferable as the main skeleton.

The energy ray polymerizable group bonded to the main chain or side chain of the energy ray curable polymer is, for example, a group containing an energy ray polymerizable carbon-carbon double bond, and specifically, a (meth) acryl group and the like can be exemplified. The energy ray polymerizable group may be bonded to the energy ray curable polymer via an alkylene group, an alkyleneoxy group, or a polyalkyleneoxy group.

The weight average molecular weight (Mw) of the energy ray-curable polymer to which the energy ray-polymerizable group is bonded is preferably 1 to 200 ten thousand, more preferably 10 to 150 ten thousand. The glass transition temperature (Tg) of the energy ray-curable polymer is preferably from-60℃to 50℃or lower, more preferably from-50℃to 40℃or lower, and still more preferably from-40℃to 30 ℃.

The energy ray-curable polymer can be obtained, for example, by reacting an acrylic polymer containing a functional group with a compound containing a polymerizable group. Examples of the functional group-containing acrylic polymer include: hydroxy, carboxyl, amino, substituted amino, epoxy, and the like. The polymerizable group-containing compound is a polymerizable group-containing compound having 1 to 5 substituents per 1 molecule which react with the substituents of the acrylic polymer and an energy ray polymerizable carbon-carbon double bond. Examples of the substituent reactive with the functional group include an isocyanate group, a glycidyl group, and a carboxyl group.

Examples of the polymerizable group-containing compound include: (meth) acryloyloxyethyl isocyanate, m-isopropenyl- α, α -dimethylbenzyl isocyanate, (meth) acryloyl isocyanate, allyl isocyanate, glycidyl (meth) acrylate, and (meth) acrylic acid.

The acrylic polymer is preferably a copolymer formed from a (meth) acrylic monomer or a derivative thereof having a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group, and another (meth) acrylate monomer or a derivative thereof capable of copolymerizing with the (meth) acrylic monomer.

Examples of the (meth) acrylic monomer having a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group or a derivative thereof include: 2-hydroxyethyl (meth) acrylate having a hydroxyl group, 2-hydroxypropyl (meth) acrylate; acrylic acid, methacrylic acid, itaconic acid having a carboxyl group; glycidyl methacrylate having an epoxy group, glycidyl acrylate, and the like.

Examples of the other (meth) acrylate monomer or derivative thereof copolymerizable with the (meth) acrylic acid monomer include alkyl (meth) acrylates having an alkyl group of 1 to 18 carbon atoms, and specific examples thereof include: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like.

Examples of the other (meth) acrylate monomer or derivative thereof copolymerizable with the (meth) acrylic monomer include (meth) acrylates having a cyclic skeleton, and specific examples thereof include: cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, imide acrylate, and the like. The acrylic polymer may be copolymerized with at least any monomer selected from vinyl acetate, acrylonitrile, and styrene, for example.

In the case of using an energy ray-curable polymer, the energy ray-polymerizable compound may be used in combination, or the binder polymer component (a) may be used in combination. Regarding the relation of the blending amounts of the three components in the 3 rd pressure-sensitive adhesive layer of the present embodiment, the content of the energy ray-polymerizable compound is preferably 1 part by weight or more and 1500 parts by weight or less, more preferably 10 parts by weight or more and 500 parts by weight or less, still more preferably 20 parts by weight or more and 200 parts by weight or less, with respect to 100 parts by weight of the total mass of the energy ray-curable polymer and the pressure-sensitive adhesive polymer component (a).

By imparting energy ray curability to the 3 rd adhesive layer, the 3 rd adhesive layer can be cured easily and in a short time, thereby improving the production efficiency of the chip with the cured adhesive layer. The cured adhesive layer may also function as a protective film for protecting the semiconductor element. Conventionally, a protective film for a semiconductor element such as a chip is generally formed of a thermosetting resin such as an epoxy resin, but since the curing temperature of the thermosetting resin exceeds 200 ℃ and the curing time takes about 2 hours, it becomes an obstacle to improving the production efficiency. However, the energy ray-curable adhesive layer can be cured in a short time by irradiation with energy rays, and therefore, a protective film can be formed easily, which contributes to improvement in production efficiency.

Other ingredients

The 3 rd pressure-sensitive adhesive layer may contain the following components in addition to the pressure-sensitive adhesive polymer component (a) and the curable component (B).

(CX) colorants

The 3 rd adhesive layer contains a Colorant (CX) in one embodiment. When the 3 rd adhesive layer is mixed with a colorant, and the 3 rd adhesive layer is cured to form a protective film for the semiconductor chip CP, the protective film shields infrared rays and the like generated by surrounding devices when the semiconductor device is assembled in the apparatus, and thus malfunction of the semiconductor device due to these infrared rays and the like can be prevented. In addition, the visibility of characters is improved when printing a product number or the like on the cured adhesive layer (protective film) obtained by curing the 3 rd adhesive layer containing the Colorant (CX). That is, in a semiconductor device or a semiconductor chip on which a protective film is formed, printing such as a product number is generally performed on the surface of the protective film by a laser marking method (a method of performing printing by removing the surface of the protective film by laser). By containing the Colorant (CX) in the protective film, a contrast difference between the laser-cut portion and the non-cut portion of the protective film can be sufficiently obtained, and visibility can be improved. As the Colorant (CX), at least any of an organic pigment, an inorganic pigment, an organic dye, and an inorganic dye can be used. The Colorant (CX) is preferably a black pigment from the viewpoint of electromagnetic wave and infrared ray shielding properties. As the black pigment, carbon black, iron oxide, manganese dioxide, aniline black, activated carbon, and the like can be used, but are not limited to these black pigments. Carbon black is particularly preferred as the Colorant (CX) from the viewpoint of improving the reliability of the semiconductor device. The Colorant (CX) may be used singly or in combination of two or more. The high curability of the 3 rd pressure-sensitive adhesive layer in this embodiment is particularly preferably exhibited when the ultraviolet light transmittance is reduced by using a colorant which can reduce the ultraviolet light transmittance as well as at least one of visible light and infrared light. The colorant that can reduce the transmittance of ultraviolet rays or at least one of visible light and infrared rays is not particularly limited as long as it is a colorant having an absorbability or a reflectivity in the wavelength range of ultraviolet rays or at least one of visible light and infrared rays, in addition to the black pigment.

The amount of the Colorant (CX) is preferably 0.1 to 35 parts by weight, more preferably 0.5 to 25 parts by weight, still more preferably 1 to 15 parts by weight, based on 100 parts by weight of the total solid content constituting the 3 rd pressure-sensitive adhesive layer.

(D) Curing accelerator

The curing accelerator (D) is used to adjust the curing speed of the 3 rd adhesive layer. The curing accelerator (D) is preferably used particularly when an epoxy resin and a thermosetting agent are used in combination in the curable component (B).

Preferable curing accelerators include: tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris (dimethylaminomethyl) phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4, 5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines such as tributylphosphine, diphenylphosphine, triphenylphosphine, etc.; tetraphenylboron salts such as tetraphenylboron tetraphenylphosphorus and triphenylphosphine tetraphenylborate. These curing accelerators may be used singly or in combination of two or more.

The content of the curing accelerator (D) is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 1 part by weight, based on 100 parts by weight of the curable component (B).

(EX) coupling agent

The coupling agent (EX) can be used to improve at least any of the adhesiveness and the adhesion of the 3 rd adhesive layer to the semiconductor element and the cohesiveness of the cured adhesive layer (protective film). In addition, by using the coupling agent (EX), the heat resistance of the cured adhesive layer (protective film) obtained by curing the 3 rd adhesive layer can be improved without impairing the heat resistance.

As the coupling agent (EX), a compound having a group reactive with the functional group of the binder polymer component (a), the curable component (B), or the like can be preferably used. As the coupling agent (EX), a silane coupling agent is preferable. Examples of such coupling agents include: gamma-glycidoxypropyl trimethoxysilane, gamma-glycidoxypropyl methyl diethoxysilane, beta- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane, gamma- (methacryloxypropyl) trimethoxysilane, gamma-aminopropyl trimethoxysilane, N-6- (aminoethyl) -gamma-aminopropyl methyl diethoxysilane, N-phenyl-gamma-aminopropyl trimethoxysilane, gamma-ureidopropyl triethoxysilane, gamma-mercaptopropyl trimethoxysilane, gamma-mercaptopropyl methyl dimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfide, methyl trimethoxysilane, methyl triethoxysilane, vinyl trimethoxysilane, vinyl triacetoxysilane, imidazole silane, and the like. These coupling agents (EX) may be used singly or in combination of two or more.

The content of the coupling agent (EX) is usually 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, more preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the total of the binder polymer component (a) and the curable component (B).

(F) Inorganic filler

By adding the inorganic filler (F) to the 3 rd pressure-sensitive adhesive layer, the thermal expansion coefficient of the cured pressure-sensitive adhesive layer (protective film) after curing can be adjusted.

Preferable examples of the inorganic filler include powders of silica, alumina, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride, and the like, beads obtained by spheroidizing these powders, single crystal fibers, glass fibers, and the like. Among these inorganic fillers, silica fillers and alumina fillers are preferable. The inorganic filler (F) may be used singly or in combination of two or more. The content of the inorganic filler (F) can be generally adjusted in the range of 1 to 80 parts by weight based on 100 parts by weight of the total solid components constituting the adhesive layer.

(G) Photopolymerization initiator

When the 3 rd pressure-sensitive adhesive layer contains an energy ray-curable component as the curable component (B), the energy ray-curable component is cured by irradiation with an energy ray such as ultraviolet rays when the composition is used. In this case, by containing the photopolymerization initiator (G) in the composition constituting the 3 rd pressure-sensitive adhesive layer, the polymerization curing time can be shortened, and the light irradiation amount can be reduced.

Specific examples of such photopolymerization initiator (G) include: benzophenone, acetophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoyl benzoic acid, methyl benzoyl benzoate, benzoin dimethyl ether, 2, 4-diethylthiazolone, alpha-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzil, dibenzyl, butanedione, 1, 2-diphenylmethane, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] acetone, 2,4, 6-trimethylbenzoyl diphenyl phosphine oxide, beta-chloroanthraquinone, and the like. The photopolymerization initiator (G) may be used singly or in combination of two or more.

The mixing ratio of the photopolymerization initiator (G) is preferably 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the energy ray-curable component. When the blending ratio of the photopolymerization initiator (G) is 0.1 part by weight or more, it is possible to prevent a problem that satisfactory transferability cannot be obtained due to insufficient photopolymerization. When the blending ratio of the photopolymerization initiator (G) is 10 parts by weight or less, it is possible to prevent the occurrence of defects such as insufficient curability of the 3 rd adhesive layer due to the formation of residues which are detrimental to photopolymerization.

(H) Crosslinking agent

In order to adjust the initial adhesion and cohesion of the 3 rd adhesive layer, a crosslinking agent may be added to the 3 rd adhesive layer. Examples of the crosslinking agent (H) include an organic polyisocyanate compound and an organic polyimide compound.

Examples of the organic polyisocyanate compound include: aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, trimers of these organic polyisocyanate compounds, terminal isocyanate urethane prepolymers obtained by reacting these organic polyisocyanate compounds with a polyol compound, and the like.

Examples of the organic polyisocyanate compound include: 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 1, 3-xylene diisocyanate, 1, 4-xylene diisocyanate, diphenylmethane-4, 4 '-diisocyanate, diphenylmethane-2, 4' -diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4, 4 '-diisocyanate, dicyclohexylmethane-2, 4' -diisocyanate, trimethylolpropane adduct toluene diisocyanate and lysine isocyanate.

Examples of the organic polyimine compound include: n, N ' -diphenylmethane-4, 4' -bis (1-aziridinecarboxamide), trimethylol propane tris (beta-aziridinyl propionate), tetramethylol methane tris (beta-aziridinylpropionate), and N, N ' -toluene-2, 4-bis (1-aziridincarboxamide) triethylenemelamine, and the like.

The crosslinking agent (H) is usually used in a ratio of 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the total amount of the binder polymer component (a) and the energy ray curable polymer.

(I) Universal additive

In addition to the above components, various additives may be blended into the 3 rd pressure-sensitive adhesive layer as required. As various additives, there may be mentioned: leveling agents, plasticizers, antistatic agents, antioxidants, ion capturing agents, getters, chain transfer agents, and the like.

The 3 rd adhesive layer containing the above-described components has adhesiveness and curability, and is easily bonded by pressing the object (semiconductor wafer, chip, or the like) in an uncured state. The 3 rd pressure-sensitive adhesive layer may have a single-layer structure, or may have a multilayer structure as long as it contains one or more layers containing the above components.

The thickness of the 3 rd adhesive layer is not particularly limited. The thickness of the 3 rd pressure-sensitive adhesive layer is preferably 3 μm or more and 300 μm or less, more preferably 5 μm or more and 250 μm or less, still more preferably 7 μm or more and 200 μm or less.

The above description is about the 3 rd adhesive layer.

Release sheet

The surface of the composite sheet 130 may be adhered with a release sheet. Specifically, the release sheet is adhered to the surface of the 3 rd adhesive layer of the composite sheet 130. The release sheet is adhered to the surface of the 3 rd adhesive layer to protect the 3 rd adhesive layer during transportation and storage. The release sheet is releasably adhered to the composite sheet 130 and is peeled from the composite sheet 130 for removal prior to use of the composite sheet 130.

The release sheet may be one having at least one surface subjected to a release treatment. Specifically, examples thereof include a release sheet having a release sheet substrate and a release agent layer formed by coating a release agent on the surface of the substrate.

[ Effect of the present embodiment ]

According to the dicing method of the present embodiment, when the 1 st sheet 10 is stretched, the back surface W3 of the semiconductor chip CP is not in contact with the 1 st adhesive layer 12 of the 1 st sheet 10. Since the protective layer 100A, which has been singulated in the dicing step, is interposed between the back surface W3 and the 1 st adhesive layer 12, the 1 st adhesive layer 12 in contact with the back surface W3 does not stretch even when the 1 st sheet 10 is stretched. As a result, according to the dicing method of the present embodiment, the residual glue can be suppressed.

In the present embodiment, the dicing sheet is not used to support the semiconductor wafer W in the dicing step, but the composite sheet 130 is used to support the semiconductor wafer W. Therefore, in order to form a layer (the protective layer 100A in the present embodiment) for protecting the rear surface W3 of the semiconductor chip CP after dicing, a layer for protecting the rear surface W3 may be formed so long as the protective layer 100A and the 3 rd sheet 30 can be peeled off from each other without performing a step of transferring the adhesive sheet used in the dicing step from another adhesive sheet.

In addition, before the dicing step is performed, it is not necessary to carefully control the depth of the dicing mark so that the dicing blade does not reach the base material of the dicing sheet in the dicing step in order to transfer the adhesive sheet used in the dicing step from the adhesive sheet used in the dicing step to the adhesive sheet used in the dicing step.

Therefore, according to the dicing method of the present embodiment, the tape structure and process can be simplified and the residual glue can be suppressed as compared with the conventional one.

Further, a method for manufacturing a semiconductor device including the dicing method according to this embodiment can be provided.

[ embodiment 3 ]

Next, embodiment 3 of the present invention will be described.

Embodiment 1 and embodiment 3 differ mainly in the following points.

In embodiment 1, a protective layer is provided on the 1 st object plane (circuit plane W1) of the object (semiconductor wafer W), and is transferred from the dicing sheet (2 nd adhesive sheet 20) to the dicing sheet (1 st sheet) after the dicing step and before the dicing step. In contrast, in embodiment 3, the object surface (back surface W3) of the object (semiconductor wafer W) 2 is bonded to the protective layer of the composite sheet having the protective layer and the 1 st sheet, whereby the protective layer is provided on the object, and the dicing step is performed without transferring the 1 st sheet to another sheet, and the expanding step is performed.

The method for expanding a sheet according to the present embodiment includes the following steps (PY 1) to (PY 3).

(PY 1) bonding the object to be processed to the protective layer having the composite sheet of the protective layer and the 1 st sheet. The protective layer has substantially the same shape as the object.

(PY 2) cutting the wafer from the object plane side of the object 1, cutting at least the protective layer, and singulating the plurality of semiconductor devices. The 1 st object plane becomes a circuit plane of the semiconductor device, and the 2 nd object plane becomes a back plane of the semiconductor device.

(PY 3) extending the 1 st sheet to expand the interval between the plurality of semiconductor devices.

Fig. 8 (fig. 8A, 8B, and 8C) and 9 are schematic cross-sectional views illustrating a method for manufacturing a semiconductor device including the dicing method of the present embodiment.

(composite sheet)

Fig. 8A shows a schematic cross-sectional view of the composite sheet 140 used in the present embodiment.

The composite sheet 140 has a protective layer 100B and a 1 st sheet 10. The composite sheet 140 holds the semiconductor wafer W when dicing the semiconductor wafer W, and the composite sheet 140 holds the semiconductor chips CP when performing the dicing step. The semiconductor wafer W is bonded to the protective layer 100B of the composite sheet 140 with the back surface W3.

The 1 st sheet 10 and the protective layer 100B bonded to the back surface W3 are preferably laminated composite sheets 140 laminated in advance.

(protective layer)

The protective layer 100B in the composite sheet 140 is laminated on the 1 st sheet 10. The protective layer 100B is not particularly limited as long as it can be bonded to the back surface W3 of the semiconductor wafer W as the object to be processed and the semiconductor chip CP as the semiconductor device (back surface of the semiconductor device) and protects the back surface W3.

In the present embodiment, the protective layer 100B has substantially the same shape as the back surface W3 of the semiconductor wafer W. The protective layer 100B is preferably shaped so as to cover the back surface W3 of the semiconductor wafer W. Therefore, the protective layer 100B is preferably formed substantially the same as the back surface W3 of the semiconductor wafer W or slightly larger than the back surface W3.

The protective layer 100B is preferably formed smaller than the 1 st sheet 10 in the sheet surface direction. A mounting frame such as a ring frame may be attached to a portion of the 1 st adhesive layer 12 of the 1 st sheet 10 where the protective layer 100B is not laminated.

The protective layer 100B of the present embodiment is formed of a single layer. The protective layer 100B may be a sheet formed by laminating a plurality of layers. The protective layer 100B is preferably formed of a single layer from the viewpoints of easiness in light transmittance control and manufacturing cost.

The thickness of the protective layer 100B is preferably 1 μm or more, more preferably 5 μm or more. The thickness of the protective layer 100B is preferably 500 μm or less, more preferably 300 μm or less.

The protective layer 100B includes, for example, a protective film and a protective sheet. As the protective layer 100B, for example, the same protective layer as the protective layer 100 described in embodiment 1 can be used. Further, another embodiment different from the protective layer 100B will be described below.

(1 st sheet)

The 1 st sheet 10 of the composite sheet 140 is a member supporting the protective layer 100B. The 1 st sheet 10 is not particularly limited as long as it can support the protective layer 100B.

The 1 st sheet 10 in the composite sheet 140 has the 1 st adhesive layer 12 and the 1 st base material 11. The 1 st sheet 10 is the same as the 1 st sheet 10 of embodiment 1.

In the present embodiment, when the 1 st sheet 10 is made of a material or the like that can be peeled from the protective layer 100B, the 1 st sheet 10 may be peeled while maintaining the state in which the protective layer 100B remains on the back surface W3 of the semiconductor chip CP.

[ lamination Process of composite sheet ]

Fig. 8B is a diagram for explaining the step (PY 1). Fig. 8B shows a semiconductor wafer W to which a composite sheet 140 having the 1 st sheet 10 and the protective layer 100B is bonded. The semiconductor wafer W in the present embodiment is also preferably a wafer obtained by a back grinding process. This step (PY 1) is sometimes referred to as a lamination step of the composite sheet.

As described later, in the step (PY 2), the semiconductor wafer W is diced and singulated into a plurality of semiconductor chips CP. In the present embodiment, the composite sheet 140 is bonded to the back surface W3 in order to hold the semiconductor wafer W when dicing the semiconductor wafer W. The semiconductor wafer W is bonded to the protective layer 100B of the composite sheet 140 with the back surface W3. The protective layer 100B is formed in substantially the same shape as the back surface W3, and thus can cover the back surface W3. In the present embodiment, the protective layer 100B is sandwiched between the semiconductor wafer W and the 1 st wafer 10.

In the present embodiment, the process is described by taking an example of a state where the circuit surface W1 is exposed, and examples of other modes include, for example: the process is performed in a state where a protective member such as a protective sheet or a protective film different from the protective layer 100B is attached to the circuit surface W1.

The step of bonding the 1 st sheet 10 and the protective layer 100B to the back surface W3 is not limited to the method using the laminated composite sheet 140, and may be, for example, a method of bonding the 1 st sheet 10 to the protective layer 100B after bonding the protective layer 100B to the back surface W3 of the semiconductor wafer W.

[ cutting procedure ]

Fig. 8C is a diagram for explaining the step (PY 2). The step (PY 2) is sometimes referred to as a dicing step. Fig. 8C shows a plurality of semiconductor chips CP held on the 1 st sheet 10.

The semiconductor wafer W having the 1 st wafer 10 and the protective layer 100B bonded to the back surface W3 is diced and singulated to form a plurality of semiconductor chips CP.

In the present embodiment, the semiconductor wafer W is cut by cutting a dicing mark from the circuit surface W1 side, and then the protective layer 100B is cut, so that the dicing mark reaches the 1 st adhesive layer 12. By this dicing, the protective layer 100B is also cut to the same size as the semiconductor chip CP.

The dicing depth at the dicing is not particularly limited as long as the semiconductor wafer W and the protective layer 100B can be singulated. In the present embodiment, the description has been given taking an example in which the dicing kerf is not cut into the 1 st base material 11, but the present invention is not limited to the embodiment. For example, in another embodiment, from the viewpoint of cutting the semiconductor wafer W and the protective layer 100B more reliably, a scribe line may be formed by dicing to a depth reaching the 1 st base material 11. In addition, the protective layer 100B may be cut without making the cut mark reach the 1 st adhesive layer 12.

In the present embodiment, a laminated structure is obtained in which the singulated protective layer 100B is sandwiched between the plurality of semiconductor chips CP and the 1 st adhesive layer 12 of the 1 st sheet 10 on the back surface W3 side of the semiconductor chip CP by the dicing step.

[ step of expanding sheet ]

Fig. 9 is a diagram for explaining the step (PY 3). The step (PY 3) is sometimes referred to as a dicing step. Fig. 9 shows a state in which the 1 st sheet 10 is stretched after the dicing process to expand the intervals of the plurality of semiconductor chips CP.

[ transfer Process, sealing Process, and other Process ]

In this embodiment, as in embodiment 1 or embodiment 2, a transfer step, a sealing step, and other steps (a rewiring layer forming step and a step of connecting to an external terminal electrode) may be performed.

(protective layer)

In one embodiment of the protective layer 100B, it is preferably formed of an uncured curable adhesive. In this case, by laminating the protective layer 100B on the object (work) such as the semiconductor wafer W and then curing the protective layer 100B, the cured product (protective film) of the protective layer 100B can be strongly adhered to the object, and a protective film having durability can be formed with respect to the semiconductor device such as the semiconductor chip CP.

The protective layer 100B preferably has adhesion at normal temperature or exhibits adhesion by heating. Thus, when the object such as the semiconductor wafer W is laminated on the protective layer 100B as described above, the two can be bonded. Therefore, positioning can be performed reliably before curing the protective layer 100B.

The curable adhesive constituting the protective layer 100B having the characteristics described above preferably contains a curable component and an adhesive polymer component. As the curable component, a thermosetting component, an energy ray curable component, or a mixture thereof can be used, but the use of a thermosetting component is particularly preferable. That is, the protective layer 100B is preferably formed of a thermosetting adhesive.

Examples of the thermosetting component include: epoxy resin, phenolic resin, melamine resin, urea resin, polyester resin, urethane resin, acrylic resin, polyimide resin, benzo Oxazine resins, and the like, and mixtures thereof. Among these resins, epoxy resins, phenolic resins, and mixtures thereof can be preferably used as the thermosetting component.

The epoxy resin has a property of forming a strong film by forming a three-dimensional network when heated. As such an epoxy resin, various epoxy resins known from the past can be used. Generally, an epoxy resin having a number average molecular weight of about 300 to 2000 is preferable, and an epoxy resin having a number average molecular weight of 300 to 500 is more preferable. It is more preferable to use a blend type epoxy resin obtained by blending an epoxy resin having a number average molecular weight of 330 to 400 and being normally liquid with an epoxy resin having a number average molecular weight of 400 to 2500 (preferably, a number average molecular weight of 500 to 2000) and being solid at normal temperature. The epoxy equivalent of the epoxy resin is preferably 50g/eq to 5000g/eq. The number average molecular weight of the epoxy resin can be obtained by a method using GPC.

Specific examples of such epoxy resins include: glycidyl ethers of phenols such as bisphenol a, bisphenol F, resorcinol, phenol novolac, cresol novolac, and the like; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, tetrahydrophthalic acid, and the like; glycidyl-type or alkyl-glycidyl-type epoxy resins in which active hydrogen bonded to nitrogen atoms such as aniline isocyanurates is substituted with a glycidyl group; so-called alicyclic epoxides, such as vinylcyclohexane diepoxide, 3, 4-epoxycyclohexylmethyl-3, 4-dicyclohexyl formate, and 2- (3, 4-epoxy) cyclohexyl-5, 5-spiro (3, 4-epoxy) cyclohexane-m-dioxane, which are obtained by introducing an epoxy group into a carbon-carbon double bond in a molecule by oxidation, for example. Further, for example, an epoxy resin having at least one skeleton selected from a biphenyl skeleton, a dicyclohexyl diene skeleton, and a naphthalene skeleton may be used.

Among specific examples of these epoxy resins, bisphenol glycidyl type epoxy resins, o-cresol novolac type epoxy resins, and phenol novolac type epoxy resins are preferably used as the epoxy resins. These epoxy resins may be used singly or in combination of two or more.

When an epoxy resin is used, a heat-activated latent epoxy resin curing agent is preferably used in combination as an auxiliary agent. The heat-activated latent epoxy resin curing agent is a curing agent which does not react with an epoxy resin at room temperature, but is activated by heating to a temperature equal to or higher than a predetermined temperature to react with the epoxy resin. The activation method of the heat-activated latent epoxy resin curing agent comprises the following steps: a method of generating active species (anions, cations) by a chemical reaction based on heating; a method of stably dispersing in an epoxy resin around room temperature and being compatible/soluble with the epoxy resin at high temperature to initiate a curing reaction; a method of initiating a curing reaction by dissolving out a molecular sieve-encapsulated curing agent at a high temperature; a method using microcapsules, and the like.

As a specific example of the heat-activated latent epoxy resin curing agent, there may be mentioned The following are listed: various kinds ofSalts, dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, imidazole compounds and other high-melting-point active hydrogen compounds. These heat-activated latent epoxy resin curing agents may be used singly or in combination of two or more. The proportion of the heat-activated latent epoxy resin curing agent used is preferably 0.1 to 20 parts by weight, more preferably 0.2 to 10 parts by weight, still more preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the epoxy resin.

As the phenol resin, there can be used, without particular limitation, condensates of phenols such as alkylphenols, polyhydric phenols and naphthols with aldehydes, and the like. Specifically, for example, can be used: phenol novolac resins, orthocresol novolac resins, para-cresol novolac resins, tert-butylphenol novolac resins, dicyclopentadiene cresol resins, poly-para-vinylphenol resins, bisphenol a novolac resins, or modified products thereof, and the like.

The phenolic hydroxyl groups contained in these phenolic resins can be easily subjected to an addition reaction with the epoxy groups of the epoxy resins by heating to form cured products having high impact resistance. Therefore, as the thermosetting component, an epoxy resin and a phenol resin may be used in combination.

The adhesive polymer component can impart moderate tackiness to the protective layer 100B. The weight average molecular weight (Mw) of the binder polymer is usually in the range of 5 to 200,preferably 10 to 150,preferably 20 to 100,. When the molecular weight is too low, the film formation of the protective layer 100B becomes insufficient, and when too high, the compatibility with other components becomes poor, which prevents uniform film formation. As such a binder polymer component, for example, can be used: at least one resin selected from the group consisting of acrylic polymers, polyester resins, phenoxy resins, urethane resins, silicone resins, and rubber polymers, and acrylic polymers are particularly preferably used.

Examples of the acrylic polymer include: (meth) acrylate copolymers formed from constituent units derived from (meth) acrylate monomers and (meth) acrylic acid derivatives. Among them, as the (meth) acrylic acid ester monomer, an alkyl (meth) acrylate having an alkyl group with 1 to 18 carbon atoms, for example, is preferably used: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and the like. Further, examples of the (meth) acrylic acid derivative include: (meth) acrylic acid, glycidyl (meth) acrylate, hydroxyethyl (meth) acrylate, and the like.

In the above, when glycidyl groups are introduced into an acrylic polymer using glycidyl methacrylate or the like as a constituent unit, the compatibility with the epoxy resin as a thermosetting component is improved, the glass transition temperature (Tg) of the protective layer 100B after curing is improved, and the heat resistance is improved. In addition, in the above, when hydroxyl groups are introduced into the acrylic polymer using hydroxyethyl acrylate or the like as a constituent unit, adhesion to a processing object and adhesive properties can be controlled.

When an acrylic polymer is used as the binder polymer, the weight average molecular weight (Mw) of the polymer is preferably 10 ten thousand or more, more preferably 15 ten thousand or more and 100 ten thousand or less. The glass transition temperature of the acrylic polymer is usually 20℃or lower, preferably about-70℃to 0℃and the acrylic polymer has adhesion at ordinary temperature (23 ℃).

The blending amount of the thermosetting component is preferably 50 parts by weight or more and 1500 parts by weight or less, more preferably 70 parts by weight or more and 1000 parts by weight or less, and still more preferably 80 parts by weight or more and 800 parts by weight or less, based on 100 parts by weight of the binder polymer component. When the thermosetting component and the binder polymer component are mixed in such a ratio, the mixture exhibits moderate tackiness before curing, and a protective film excellent in film strength can be obtained after curing while stably performing the bonding operation.

The protective layer 100B preferably contains at least one of a colorant and a filler, and particularly preferably contains both a colorant and a filler.

As the colorant, for example, a known colorant such as an inorganic pigment, an organic pigment, or an organic dye can be used, but from the viewpoint of improving the light transmittance control, it is preferable that the colorant contains an organic colorant. From the viewpoint of improving the chemical stability of the colorant (specifically, the low solubility, the low liability of color transfer, and the small degree of change with time), it is preferable that the colorant be composed of a pigment.

Examples of the filler include: silica such as crystalline silica, fused silica and synthetic silica, and inorganic filler such as alumina and glass spheres. Among these inorganic fillers, silica is preferable, and synthetic silica is more preferable, and synthetic silica of the type in which an α -ray source that is a main cause of malfunction of a semiconductor device is removed as much as possible is preferable. Examples of the shape of the filler include spherical, needle-like, and irregular shapes, and preferably spherical, more preferably spherical.

In addition, the protective layer 100B may contain a coupling agent. By containing the coupling agent, after the protective layer 100B is cured, the adhesiveness/adhesiveness between the protective film and the object can be improved without impairing the heat resistance of the protective film, and the water resistance (wet heat resistance) can be improved. As the coupling agent, a silane coupling agent is preferable in view of its versatility, cost advantage, and the like.

Examples of the silane coupling agent include: gamma-glycidoxypropyl trimethoxysilane, gamma-glycidoxypropyl methyl diethoxysilane, beta- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane, gamma- (methacryloxypropyl) trimethoxysilane, gamma-aminopropyl trimethoxysilane, N-6- (aminoethyl) -gamma-aminopropyl methyl diethoxysilane, N-phenyl-gamma-aminopropyl trimethoxysilane, gamma-ureidopropyl triethoxysilane, gamma-mercaptopropyl trimethoxysilane, gamma-mercaptopropyl methyl dimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfide, methyl trimethoxysilane, methyl triethoxysilane, vinyl trimethoxysilane, vinyl triacetoxysilane, imidazole silane, and the like. As the silane coupling agent, one of these may be used alone, or two or more may be used in combination.

In order to adjust the cohesive force before curing, the protective layer 100B may contain a crosslinking agent such as an organic polyisocyanate compound, an organic polyimine compound, or an organometallic chelate compound. In addition, an antistatic agent may be contained in the protective layer 100B in order to suppress static electricity and improve the reliability of the chip. Further, in order to improve the flame retardant performance of the protective film and to improve the reliability as a package, the protective layer 100B may contain a flame retardant such as a phosphoric acid compound, a bromine compound, or a phosphorus compound.

The thickness of the protective layer 100B is not particularly limited. When the protective layer 100B is cured and used as a protective film, the thickness of the protective layer 100B is preferably 3 μm or more and 300 μm or less, more preferably 5 μm or more and 200 μm or less, and still more preferably 7 μm or more and 100 μm or less in order to effectively exhibit the function as a protective film.

[ Effect of the present embodiment ]

According to the dicing method of the present embodiment, when the 1 st sheet 10 is stretched, the back surface W3 of the semiconductor chip CP is not in contact with the 1 st adhesive layer 12 of the 1 st sheet 10. Since the protective layer 100B, which has been singulated in the dicing step, is interposed between the back surface W3 and the 1 st adhesive layer 12, the protective layer 100B in contact with the back surface W3 does not stretch even when the 1 st sheet 10 is stretched. As a result, according to the dicing method of the present embodiment, the residual glue can be suppressed.

In the present embodiment, the protective layer 100B has substantially the same shape as the back surface W3 of the semiconductor wafer W, and the protective layer 100B is singulated from the back surface W3 of the semiconductor chip CP (semiconductor chip on the outer peripheral side) formed on the end portion side of the semiconductor wafer W by dicing, so that the interval between the semiconductor chips CP can be sufficiently widened.

In the present embodiment, the semiconductor wafer W is not supported by the dicing sheet but by the composite sheet 140 having the 1 st sheet 10 and the protective layer 100B in the dicing step. Therefore, in order to form a layer (the protective layer 100B in the present embodiment) for protecting the rear surface W3 of the semiconductor chip CP after dicing, a step of transferring the adhesive sheet used in the dicing step from the adhesive sheet to another adhesive sheet may not be performed, and the process can be simplified.

In addition, the adhesive sheet used in the dicing step does not need to be transferred from the adhesive sheet used in the dicing step to the adhesive sheet used in the dicing step before the dicing step is performed.

Therefore, according to the dicing method of the present embodiment, the process can be simplified as compared with the conventional one, and the residual glue can be suppressed while the space between the chips is sufficiently expanded.

[ modification of embodiment ]

The present invention is not limited to any of the above embodiments. The present invention includes embodiments and the like obtained by modifying the above-described embodiments within a range that can achieve the object of the present invention.

For example, the semiconductor wafer, the circuits in the semiconductor chip, and the like are not limited to the illustrated arrangement, shape, and the like. The connection structure with the external terminal electrode and the like in the semiconductor package are not limited to those described in the above embodiments. In the above-described embodiment, the description has been given taking the mode of manufacturing the FO-WLP type semiconductor package as an example, but the present invention is also applicable to the mode of manufacturing other semiconductor packages such as the fan-in type WLP.

The above-described method for producing FO-WLP may be modified in part of the steps or may omit part of the steps.

The dicing in the dicing step may be performed by irradiating the semiconductor wafer with laser light instead of using the above-described dicing mechanism. For example, the semiconductor wafer may be completely diced by irradiating a laser beam, and singulated into a plurality of semiconductor chips. In these methods, the irradiation of the laser light may be performed from any side of the semiconductor wafer.

In embodiment 2, the composite sheet 130 is described as having the protective layer 100A and the 3 rd sheet 30, or having the protective layer 100A as the 3 rd adhesive layer and the 3 rd sheet 30 as the 3 rd base material, but the present invention is not limited to these forms. For example, the pressure-sensitive adhesive sheet may be one having a release layer between the 3 rd pressure-sensitive adhesive layer and the 3 rd base material. The release layer is preferably formed using the same material as the release sheet described in embodiment 1.

Examples

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples at all.

(production of adhesive sheet)

Example 1

62 parts by weight of Butyl Acrylate (BA), 10 parts by weight of Methyl Methacrylate (MMA), and 28 parts by weight of 2-hydroxyethyl acrylate (2 HEA) were copolymerized to obtain an acrylic copolymer. A solution (adhesive base, solid content: 35.0 mass%) of the resin (acrylic acid A) was prepared by adding 2-isocyanate ethyl methacrylate (product name "Karenz MOI" (registered trademark)) to the acrylic copolymer. The addition ratio is as follows: the amount of ethyl 2-isocyanate methacrylate was set to 90 mol% relative to 100 mol% of 2HEA of the acrylic copolymer.

The weight average molecular weight (Mw) of the resulting resin (acrylic acid A) was 60 million, and Mw/Mn was 4.5. The weight average molecular weight Mw and the number average molecular weight Mn converted to standard polystyrene were measured by Gel Permeation Chromatography (GPC), and the molecular weight distribution (Mw/Mn) was obtained from each measurement value.

To this adhesive base, UV resin a (10-functional urethane acrylate, mitsubishi chemical co., product name "UV-5806", mw=1740, including photopolymerization initiator), and toluene diisocyanate-based crosslinking agent (product name "cornate L", manufactured by japan polyurethane industrial co., ltd.) as a crosslinking agent were added. 50 parts by weight of UV resin A and 0.2 part by weight of a crosslinking agent were added to 100 parts by weight of the solid content in the adhesive main agent. After the addition, stirring was carried out for 30 minutes to prepare an adhesive composition A1.

Next, the prepared solution of the adhesive composition A1 was applied to a polyethylene terephthalate (PET) release film (product name "SP-PET381031", manufactured by lindeke corporation, thickness 38 μm) and dried, and an adhesive layer having a thickness of 40 μm was formed on the release film.

After a polyester-based polyurethane elastomer sheet (product name "Higress DUS202", thickness 100 μm) as a base material was bonded to the pressure-sensitive adhesive layer, an unnecessary portion of the end portion in the width direction was cut and removed to prepare a pressure-sensitive adhesive sheet SA1.

(method for measuring chip Interval)

The pressure-sensitive adhesive sheet obtained in example 1 was cut into pieces of 210mm×210mm to obtain test pieces. At this time, the cutting is performed such that each side of the cut sheet is parallel or perpendicular to the MD direction of the base material in the adhesive sheet.

The semiconductor chips to be bonded to the adhesive sheet were prepared in the order shown below. A sheet as a protective layer (in the example, sometimes referred to as a protective sheet) was bonded to a 6-inch silicon wafer. As the protective sheet, "E-3125KL" (product name) manufactured by Lindeke Co., ltd. Next, a 6-inch silicon wafer was cut from the protective sheet side so that chips of 3mm×3mm size were 5 columns in the X-axis direction and 25 chips in total were cut out in 5 columns in the Y-axis direction. For each chip, a cut protective sheet was attached.

The release film of the test piece was peeled off, and the protection piece side of the cut total of 25 chips was adhered to the center portion of the exposed adhesive layer. At this time, the chips are arranged in 5 rows in the X-axis direction and 5 rows in the Y-axis direction.

Next, the test piece to which the chip is attached is set in a biaxial stretching dicing apparatus (separation apparatus). Fig. 10 shows a plan view illustrating the expanding device 400. In fig. 10, the X-axis and the Y-axis are in an orthogonal relationship, the positive direction of the X-axis is defined as the +x-axis direction, the negative direction of the X-axis is defined as the-X-axis direction, the positive direction of the Y-axis is defined as the +y-axis direction, and the negative direction of the Y-axis is defined as the-Y-axis direction. The test piece 500 is provided in the dicing device 400 such that each side is parallel to the X-axis or the Y-axis. As a result, the MD direction of the base material in the test piece 500 is parallel to the X-axis or the Y-axis. In fig. 10, the chip is omitted.

As shown in fig. 10, the film expander 400 includes 5 holding mechanisms 401 (20 holding mechanisms 401 in total) in the +x-axis direction, -X-axis direction, +y-axis direction, and-Y-axis direction, respectively. Of the 5 holding mechanisms 401 in each direction, the holding mechanism 401A is located at both ends, the holding mechanism 401C is located at the center, and the holding mechanism 401B is located between the holding mechanisms 401A and 401C. Each side of the test piece 500 is gripped by these holding mechanisms 401.

Here, as shown in fig. 10, the side length of the test piece 500 is 210mm. The distance between the holding mechanisms 401 on the respective sides is 40mm. The distance between the end portion (the apex of the sheet) on one side of the test piece 500 and the holding mechanism 401A located on the side and closest to the end portion is 25mm.

Next, a plurality of tension applying mechanisms, not shown, corresponding to the respective holding mechanisms 401 are driven so that the holding mechanisms 401 each independently move. Four sides of the test piece were fixed by a holding jig, and the test piece was expanded at a speed of 5mm/s and an expansion amount of 200mm in the X-axis direction and the Y-axis direction, respectively. Then, the expanded state of the test piece 500 is maintained by the ring frame.

The distance between the chips was measured by a digital microscope while the expanded state was maintained, and the average value of the distance between the chips was used as the chip interval.

A qualified "A" is determined when the chip interval is 1800 μm or more, and a disqualified "B" is determined when the chip interval is less than 1800 μm.

(method for measuring chip alignment)

The rate of deviation of the adjacent chips with respect to the center line in the X-axis and Y-axis directions of the workpiece from which the chip spacing was measured.

Fig. 11 shows a schematic diagram of a specific measurement method.

A row of 5 chips was selected in the X-axis direction, and the distance Dy between the uppermost end of the chip and the lowermost end of the chip in the row was measured by a digital microscope. The Y-axis deviation rate was calculated based on the following expression (expression 3). Sy is the chip size in the Y-axis direction, and is set to 3mm in this example.

Deviation in Y-axis direction [% ] = [ (Dy-Sy)/2 ]/Syx 100. Cndot. Of formula 3

The Y-axis deviation rate was calculated similarly for the other 4 columns in which 5 chips were arranged in the X-axis direction.

A column in which 5 chips were arranged was selected in the Y-axis direction, and the distance Dx between the leftmost end of the chip and the rightmost end of the chip in the column was measured by a digital microscope. The deviation ratio in the X-axis direction was calculated based on the following expression (expression 4). Sx is the chip size in the X-axis direction, and is set to 3mm in this embodiment.

Deviation in X-axis direction [% ] = [ (Dx-Sx)/2 ]/Sx×100. Cndot. (formula 4)

The deviation rate in the X-axis direction was calculated similarly for the other 4 columns in which 5 chips were arranged in the Y-axis direction.

In the expressions (expression 3) and (expression 4), division by 2 is to represent the maximum distance of the chip from the given position after expansion in absolute value.

A case where the deviation ratio is less than + -10% in all columns (10 columns in total) in the X-axis direction and the Y-axis direction is judged as a qualified "A", and a case where the deviation ratio is + -10% or more in 1 or more columns is judged as a disqualified "B".

(evaluation method of residual glue)

After the dicing was performed under the conditions described in the above-mentioned method for measuring the chip spacing, the dicing was performed using an ultraviolet irradiation device (RAD-2000 m/12, manufactured by Leideco Co., ltd.) at an illuminance of 220mW/cm from the surface of the adhesive sheet of example 1 opposite to the surface on which the chips were mounted ² Light quantity 460mJ/cm ² Ultraviolet irradiation was performed under the conditions of (2). After the irradiation of ultraviolet rays, the chip was held by an adsorption tape, and the adhesive sheet was peeled off. After the pressure-sensitive adhesive sheet was peeled off, the surface of the chip to which the pressure-sensitive adhesive sheet was bonded was observed with an optical microscope. No residual glue is observed on the chip surface The case was judged as "A" and the case where the residual glue was observed was judged as "B" failed.

When the adhesive sheet of example 1 was used for the dicing, the evaluation result of the chip spacing was a qualified "a" judgment, and the evaluation result of the chip alignment was a qualified "a" judgment.

When the adhesive sheet of the example was subjected to a sheet expansion with a protective sheet interposed between the chip and the adhesive sheet, the evaluation result of the residual glue on the chip surface was judged as a pass "a".

Claims

1. A method of expanding a slice, the method comprising:

a step of expanding the 1 st sheet on which the plurality of semiconductor devices are bonded to expand the interval between the plurality of semiconductor devices,

the plurality of semiconductor devices each have a 1 st semiconductor device face and a 2 nd semiconductor device face on the opposite side of the 1 st semiconductor device face,

the plurality of semiconductor devices are bonded to each other with a protective layer interposed between the 1 st semiconductor device side or the 2 nd semiconductor device side and the 1 st sheet,

the plurality of semiconductor devices are obtained by forming the protective layer on the object to be processed and dicing the object to be processed and the protective layer,

the protective layer is an adhesive sheet having an adhesive layer and a base material,

The 1 st sheet has a 1 st base material and a 1 st adhesive layer.

2. The method for expanding a patch according to claim 1, wherein,

after the protective layer is formed on the 1 st semiconductor device surface, the plurality of semiconductor devices are bonded to the 1 st wafer.

3. The method for expanding a patch according to claim 1, wherein,

attaching the object having the protective layer formed thereon to the 2 nd adhesive layer of a 2 nd adhesive sheet having a 2 nd adhesive layer and a 2 nd base material,

dicing the protective layer and the object to obtain the plurality of semiconductor devices,

and attaching the 1 st piece to the cut protective layer.

4. The method for expanding a patch according to claim 3, wherein,

and peeling the 2 nd adhesive sheet after bonding the 1 st sheet to the cut protective layer.

5. The method for expanding a patch according to claim 1, wherein,

attaching the object to be processed to the protective layer of the composite sheet having the protective layer and the 3 rd sheet,

cutting the object to be processed and the protective layer to obtain the plurality of semiconductor devices,

and peeling the 3 rd sheet from the protective layer.

6. The method for expanding a patch according to claim 1, wherein,

The protective layer and the 1 st sheet are laminated together in advance,

the object is supported by the protective layer,

and cutting the object to be processed and the protective layer to obtain the plurality of semiconductor devices.

7. The method for expanding a patch according to claim 1, wherein,

the object to be processed is a semiconductor wafer.

8. The method for expanding a patch according to claim 1, wherein,

the 1 st piece is an expansion piece.

9. The method for expanding a sheet according to any one of claims 1 to 8, wherein,

the 1 st semiconductor device side has a circuit.

10. A method for manufacturing a semiconductor device, the method comprising the dicing method according to any one of claims 1 to 9.