Method of manufacturing multilayer sheet and laminate

Abstract

To prevent peeling failure when a multi-layer sheet is subjected to a lamination process. A multi-layer sheet (100) in which the multi-layer sheet (100) has a first base film (12), an adhesive film (14), a second base film (16), and a third base film (18) stacked in this order, and satisfies the following formula (1). · Formula (1) P1 < P2 < P3 [In the formula, P1 represents the peeling strength of the first base film and the adhesive film, P2 represents the peeling strength of the adhesive film and the second base film, and P3 represents the peeling strength of the second base film and the third base film].

Description

Technical Field

[0001] This invention relates to a method for manufacturing multilayer sheets and laminates. Background Technology

[0002] In the manufacturing processes of various products such as semiconductor devices, there are cases where a lamination process is performed using a multilayer sheet consisting of an adhesive film and one or more other films (hereinafter referred to as "substrate films") disposed on both sides of the adhesive film (for example, Patent Document 1, etc.). The lamination process typically includes the following first step (first substrate film peeling step) and second step (laminate formation step). (1) First step: Peel off the substrate film (first substrate film) set on one side of the multilayer sheet to expose one side of the adhesive film. (2) Second process: The laminate is obtained by attaching the laminated object (e.g., semiconductor wafer) to the surface of the exposed adhesive film and heating and pressurizing it. Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-2231 Summary of the Invention The technical problem that the invention aims to solve

[0004] In addition, when performing lamination, from the perspective of product production efficiency and manufacturing cost, there is a situation where it is preferable to perform the semi-cutting process described below before performing the first process, and to perform the second region peeling process described below after performing the semi-cutting process and before or at the same time as performing the first process. (P1) Half-cutting process: The multilayer sheet is partially cut (half-cut) from one side in such a way that the adhesive film is also cut to the middle of the thickness direction of the multilayer sheet. The cut line formed by cutting the one side is used as the boundary line to divide the sheet into a first region (e.g., a circular region) and a second region (the region other than the first region). (P2) Second region peeling process: Selectively peel (remove) the second region formed on one side of the multilayer sheet, including the adhesive film layer. Then, having implemented these processes, the first and second processes are performed on the first area.

[0005] On the other hand, the multilayer sheet, in which a (first) substrate film, an adhesive film, and a (second) substrate film are sequentially stacked, has a simple three-layer structure and is a typical and representative type of multilayer sheet used for lamination processing. Furthermore, the inventors have confirmed that, even when using a multilayer sheet with the aforementioned three-layer structure during lamination processing including the aforementioned half-cutting step and the second region peeling step, either or both of the two types of peeling defects described below can occur simultaneously. (D1) Poor peeling (excessive peeling): Regarding the first process, in the first area, the adhesive film (which should not have been peeled off) became integral with the substrate film (first substrate film) on one side and was also peeled off. (D2) Poor peeling (too small peeling): Regarding the second area peeling process, for the second area, part or all of the adhesive film (which should have been peeled off as an integral part of the substrate film (first substrate film) on one side) is attached to the substrate film (second substrate film) on the other side and remains.

[0006] The present invention was made in view of the above circumstances, and its object is to provide a multilayer sheet and a method for manufacturing a laminate using the multilayer sheet, wherein the multilayer sheet is capable of suppressing the occurrence of the two types of peeling defects mentioned above during the lamination process, the lamination process including a half-cutting process and a second region peeling process, the half-cutting process dividing one surface into a first region and a second region by half-cutting, and the second region peeling process selectively peeling the second region from the multilayer sheet in a manner that also includes an adhesive film layer. Technical means to solve technical problems

[0007] The aforementioned problem is achieved through the following invention. That is, The multilayer sheet of the present invention comprises a first substrate film, an adhesive film, a second substrate film and a third substrate film, wherein the multilayer sheet is sequentially stacked with the first substrate film, the adhesive film, the second substrate film and the third substrate film, and satisfies the following formula (1). Equation (1) P1 <P2<P3 [In formula (1), P1 represents the peel strength (N / 250mm) between the first substrate film and the adhesive film, P2 represents the peel strength (N / 250mm) between the adhesive film and the second substrate film, and P3 represents the peel strength (N / 250mm) between the second substrate film and the third substrate film.]

[0008] One embodiment of the multilayer sheet of the present invention preferably satisfies the following formula (2). Equation (2) Q2 / Q3≤2.0 [In equation (2), Q2 represents the elastic modulus (MPa) of the second substrate film, and Q3 represents the elastic modulus (MPa) of the third substrate film.]

[0009] In other embodiments of the multilayer sheet of the present invention, the peel strength P3 is preferably 0.5N / 250mm to 15N / 250mm.

[0010] In other embodiments of the multilayer sheet of the present invention, the peel strength P2 is preferably greater than 0.1 N / 250 mm and less than 5 N / 250 mm.

[0011] In other embodiments of the multilayer sheet of the present invention, the peel strength P1 is preferably 0.1 N / 250 mm or more and less than 5 N / 250 mm.

[0012] In other embodiments of the multilayer sheet of the present invention, the third substrate film is preferably composed of a PET film and a pressure-sensitive adhesive layer (adhesive layer) disposed on at least one side of the PET film.

[0013] In another embodiment of the multilayer sheet of the present invention, the side of the second substrate film that is in close contact with the adhesive film is preferably demolded.

[0014] In other embodiments of the multilayer sheet of the present invention, the adhesive film is preferably composed of a resin composition containing epoxy resin, curing agent, inorganic filler and black pigment.

[0015] In another embodiment of the multilayer sheet of the present invention, the side of the first substrate film that is in close contact with the adhesive film is preferably demolded.

[0016] Other embodiments of the multilayer sheet of the present invention are preferably used in the manufacture of semiconductor devices.

[0017] The manufacturing method of the laminate of the present invention preferably includes: a semi-cutting process: while partially cutting the multilayer sheet of the present invention from the side of the multilayer sheet on which the first substrate film is disposed, in a manner that separates the first substrate film, the adhesive film, and the second substrate film, to the middle of the thickness direction of the multilayer sheet, the side of the multilayer sheet on which the first substrate film is disposed is divided into a first region and a region other than the first region, i.e., a second region, by using the cut line formed by the cut as a boundary line; a second region peeling process: for the second region, at the interface between the second substrate film and the third substrate film... Peeling; First step: peeling at the interface between the first substrate film and the adhesive film in the first region; and second step: forming a laminate by heating and pressurizing the laminate, the laminate being a laminate obtained by bonding the adhesive film of the sheet body to the surface of the laminated object component, the sheet body being one of two sheets obtained by separating the multilayer sheet into two in the thickness direction through at least the second region peeling step and the first step, the sheet body having the second substrate film and the adhesive film sequentially laminated on one side of the third substrate film and in the first region.

[0018] In one embodiment of the method for manufacturing the laminate of the present invention, the first step is preferably performed after the second region peeling step.

[0019] In other embodiments of the method for manufacturing the laminate of the present invention, the second region peeling process and the first process are preferably performed substantially simultaneously.

[0020] In other embodiments of the method for manufacturing the laminate of the present invention, the multilayer sheet is preferably a strip sheet.

[0021] In other embodiments of the method for manufacturing the laminate of the present invention, the first region is preferably a plurality of circular regions or approximately circular regions arranged along the length direction of the multilayer sheet.

[0022] In other embodiments of the method for manufacturing the laminate of the present invention, the laminated object is preferably a semiconductor wafer or a glass wafer. Beneficial effects

[0023] According to the present invention, a multilayer sheet and a method for manufacturing a laminate using the multilayer sheet are provided, wherein the multilayer sheet is capable of suppressing the occurrence of the two types of peeling defects mentioned above during the lamination process, the lamination process including a half-cutting process and a second region peeling process, the half-cutting process dividing a surface of one side into a first region and a second region by half-cutting, and the second region peeling process selectively peeling the second region from the multilayer sheet in a manner that also includes an adhesive film layer. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating an example of a lamination process using multilayer sheets. Figure 2 This is a cross-sectional view showing an example of the cross-sectional structure of the multilayer sheet in this embodiment. Figure 3 This is a schematic diagram illustrating an example of a half-cut multilayer sheet in the lamination process (first process and second process) of the multilayer sheet using this embodiment. Here, Figure 3 (a) is a top view showing an example of a multi-layered sheet after being partially cut, viewed from the half-cut side. Figure 3 (b) is Figure 3 The cross-sectional view between reference numerals AA in (a) of the figure. Figure 4 This is a top view showing an example of a state in which a peeling tape is attached to the half-cut surface of a multilayer sheet after half-cutting, in the lamination process (first process) of the multilayer sheet using this embodiment. Figure 5 This is a cross-sectional view showing the state in which the multilayer sheet is separated into a main sheet portion and a non-main sheet portion during the lamination process (first process) using the multilayer sheet of this embodiment. Here, Figure 5 (a) is a cross-sectional view of the main body of the sheet. Figure 5 (b) is a cross-sectional view of the unused portion of the sheet. Figure 6 This is a cross-sectional view showing the state in which the multilayer sheet is separated into a main sheet portion and a non-main sheet portion during the lamination process (second process) of the multilayer sheet using this embodiment. Here, Figure 6 (a) is a cross-sectional view of the main body of the sheet. Figure 6 (b) is a cross-sectional view of the unused portion of the sheet. Figure 7 This indicates that in the lamination process (second process) of the multilayer sheet using this embodiment, Figure 6 (a) is a top view of an example of a sheet body with a peeling tape attached to a half-cut surface. Figure 8 This indicates that in the lamination process (second process) of the multilayer sheet using this embodiment, for Figure 7 The diagram shows a cross-sectional view of the sheet body after the first process (first substrate film peeling process) has been performed. Figure 9 It is a cross-sectional diagram showing the cross-sectional structure of a conventional multi-layer sheet material. Figure 10This is a schematic diagram illustrating an example of a half-cut multilayer sheet in a conventional lamination process (first process and second process). Here, Figure 10 (a) is a top view showing an example of a multi-layered sheet after being partially cut, viewed from the half-cut side. Figure 10 (b) is Figure 10 The cross-sectional view between reference numerals B and C in (a). Figure 11 This is a top view showing an example of a multi-layer sheet with a peeling tape adhered to the half-cut surface after half-cutting, in a conventional multi-layer sheet lamination process (first process). Figure 12 This is a cross-sectional view showing the state in which the multilayer sheet is separated into a main sheet portion and a non-main sheet portion during a conventional lamination process (first process). Here, Figure 12 (a) is a cross-sectional view of the main body of the sheet. Figure 12 (b) is a cross-sectional view of the unused portion of the sheet. Figure 13 This is a cross-sectional view showing the state in which the multilayer sheet is separated into a main sheet portion and a non-main sheet portion during a conventional lamination process (second process). Here, Figure 13 (a) is a cross-sectional view of the main body of the sheet. Figure 13 (b) is a cross-sectional view of the unused portion of the sheet. Figure 14 This indicates that in the conventional lamination process (second process) for multi-layer sheets, Figure 13 (a) is a top view of an example of a sheet body with a peeling tape attached to a half-cut surface. Figure 15 This indicates that in the conventional lamination process (second process) for multi-layer sheets, the lamination process is performed on... Figure 14 The diagram shows a cross-sectional view of the sheet body after the first process (first substrate film peeling process) has been performed. Figure 16 This is a cross-sectional view of the sheet body showing a state of poor peeling (too small peel) that occurred during the conventional lamination process for multi-layer sheets (first process and second process). Here, Figure 16 (a) is a cross-sectional view of the sheet body showing a state of poor peeling (too small peeling) that occurred in the first process. Figure 16 (b) is a cross-sectional view of the sheet body showing a state of poor peeling (too small peeling) that occurred in the second process. Figure 17This is a cross-sectional view of the sheet body showing a state of poor peeling (over-peeling) that occurred during conventional multilayer sheet lamination processes (first process and second process). Here, Figure 17 (a) is a cross-sectional view of the sheet body showing a state of poor peeling (over-peeling) that occurred in the first process. Figure 17 (b) is a cross-sectional view of the sheet body showing a state of poor peeling (over-peeling) that occurred in the second process. Detailed Implementation

[0025] (Poor peeling of multi-layer sheets in the past) In studying the multilayer sheet of this embodiment described later, the inventors first investigated the peeling defects that occurred when a lamination process including a half-cutting process and a second region peeling process was performed using a multilayer sheet having a conventional three-layer structure.

[0026] Figure 1 This is a schematic diagram illustrating an example of a lamination process using multilayer sheets. Specifically, it is a side view of the multilayer sheet during the lamination process, observed from one side along the width direction of the multilayer sheet. Additionally, in Figure 1 In this drawing, detailed descriptions of the cross-sectional structure of the multi-layer sheet are omitted (details of the cross-sectional structure are explained in other figures). Furthermore, in... Figure 1 In the other accompanying figures described later, the X, Y, and Z directions refer to mutually orthogonal directions. The plane containing the X and Y directions, i.e., the XY plane, is a horizontal plane, and the Z direction is a vertical direction. Furthermore, in these figures, there are instances where the X1 direction is referred to as the right (side, direction), the X2 direction as the left (side, direction), the Z1 direction as the top (side, direction), the Z2 direction as the bottom (side, direction), and the Y direction as the width direction (of the multi-layer sheet).

[0027] The conveying path of the multilayer sheet 10 during lamination is summarized as follows: First, the multilayer sheet 10, supplied by a multilayer sheet supply roller (not shown), is conveyed from the right side to the half-cutting section HC. After passing the half-cutting section HC, it is further conveyed to the left side, reaching the peeling section P. Then, at the peeling section P, a portion of the multilayer sheet 10 is peeled off, separating it into a sheet body portion 10A and a sheet unwanted portion 10B. Then, the sheet body portion 10A is further conveyed to the left side from the peeling section P, moving towards the lamination section R. On the other hand, the sheet unwanted portion 10B, after being temporarily conveyed to the lower right side from the peeling section P, is further conveyed to the right side and finally wound onto a unwanted portion recovery roller (not shown).

[0028] The half-cutting part HC is equipped with a rotation axis and a Y-direction (and) Figure 1A pair of rollers arranged parallel to each other (in the direction perpendicular to the paper surface) consists of a support roller 20 and a half-cutting roller 22 arranged opposite to the support roller 20 on the lower side. At least one of the rollers is rotated by an electric motor. Furthermore, a flat cutter for half-cutting is mounted on the outer peripheral surface of the half-cutting roller 22. The flat cutter has a blade shape corresponding to the shape used for half-cutting the multilayer sheet 10. Then, when the multilayer sheet 10 passes between the support roller 20 and the half-cutting roller 22, the multilayer sheet 10 is half-cut by pressing the flat cutter into one side of the multilayer sheet 10.

[0029] The peeling section P includes peeling claws 30 and a support roller 32 arranged with its rotation axis parallel to the Y direction. The peeling claws 30 are configured to contact the lower surface of the multilayer sheet 10 located between the half-cut section HC and the laminating section R, and the support roller 32 is configured to contact the lower surface of the sheet body section 10A located between the half-cut section HC and the laminating section R. Furthermore, in the conveying direction (X2 direction) of the multilayer sheet 10, the support roller 32 is positioned relative to the peeling claws 30 on the laminating section R side. The peeling claws 30 have a first support surface 30S1 parallel to the conveying direction (X2 direction) of the multilayer sheet 10 and in contact with the lower surface of the multilayer sheet 10, and a second support surface 30S2 in contact with one side of the sheet blank section 10B and intersecting the first support surface 30S1 at an acute angle. Furthermore, the area near the top end 30T where the first support surface 30S1 and the second support surface 30S2 intersect is a curved surface. Furthermore, at the top end 30T of the peeling claw 30, for the multilayer sheet 10 that has passed through the semi-cutting section HC and been conveyed to the peeling section P, the tension pulling to the left and the tension pulling to the lower right act simultaneously, thereby separating the multilayer sheet 10 into a sheet body section 10A conveyed to the left and a sheet non-contained section 10B conveyed to the lower right.

[0030] During separation, to prevent the newly separated sheet body 10A from being pulled downwards, the lower surface of the sheet body 10A is supported by a support roller 32 that rotates passively as the sheet body 10A is conveyed. Then, the separated sheet body 10A is conveyed to the laminating section R. Furthermore, when the separated unwanted sheet portion 10B is conveyed to a support roller 40 located on the lower right side of the peeling section P and whose rotation axis is parallel to the Y-axis, the conveying direction is changed from the lower right direction to the right direction using this support roller 40 as a fulcrum, and finally wound onto a unwanted portion recovery roller (not shown).

[0031] The laminating section R includes a pair of pressure rollers 50 and 52, whose rotation axes are parallel to and opposite to each other in the Y direction. At least one of the rollers is rotated by an electric motor. Furthermore, the laminating section R also includes a heating means (heater, etc.) not shown. The heating means may be built into at least one of the pair of pressure rollers 50 and 52, or may be disposed near the pressure rollers 50 and 52. Moreover, the pair of pressure rollers 50 and 52 are configured such that pressure roller 50 is positioned above pressure roller 52. During lamination, the outer peripheral surface of pressure roller 50 presses against the upper surface of the sheet body 10A, and the outer peripheral surface of pressure roller 52 presses against the lower surface of the laminating target component 200. In the lamination section R, near its entrance (near the right side of the lamination section R), the lamination target component 200 is supplied from the lower surface side of the sheet body 10A that is conveyed to the lamination section R, thereby forming a laminate containing the sheet body 10A and the lamination target component 200. As the laminate passes between the pressure rollers 50 and 52, it is heated and pressurized to obtain a laminate. Thus, the lamination process is completed. Then, according to the shape and structure of the final product, predetermined subsequent processes are sequentially performed on the laminate.

[0032] On the other hand, the strip-shaped multilayer sheet 10 with a conventional three-layer structure used for lamination processing has Figure 9 The cross-sectional structure shown. Additionally... Figure 9 The cross-sectional structure of the multilayer sheet 10 shown represents the state just before the half-cut portion HC is half-cut. The multilayer sheet 10 is a sheet with a three-layer structure having a first substrate film 12, an adhesive film 14, and a second substrate film 16 stacked sequentially. For the multilayer sheet 10, near the entrance of the half-cut portion HC ( Figure 1 (near the right side of the half-cut portion HC in the middle), such as Figure 9 The first substrate film 12 shown is located on the lower surface side. Furthermore, the side of the multilayer sheet 10 on which the first substrate film 12 is disposed is the side that is to be half-cut (half-cut surface 10C), and the side of the multilayer sheet 10 opposite to the half-cut surface 10C is the side that is not to be half-cut (non-half-cut surface 10N).

[0033] Furthermore, when the peel strength between the first substrate film 12 and the adhesive film 14 is set to p1, and the peel strength between the adhesive film 14 and the second substrate film 16 is set to p2, the peel strengths p1 and p2 can be set to satisfy any one of the following formulas (A) to (C). However, for ease of explanation, it is assumed that formula (A) is satisfied in the description of the first and second processes described later. Furthermore, for reference, in Figure 9 In the other accompanying drawings, the interfaces and peel strengths p1 and p2 between the films are marked as needed. Formula (A) p1 <p2 Equation (B) p1>p2 Equation (C) p1=p2

[0034] When laminating using multilayer sheet 10, each process can be implemented in two modes (first process or second process). Furthermore, although the order of the processes differs between the first and second processes, the resulting laminates have the same structure. The first and second processes are described in detail below.

[0035] <First Process> In the first process, a semi-cutting process is first performed on the multilayer sheet 10 in the semi-cutting section HC. In the semi-cutting process, the multilayer sheet 10 is partially cut from the side of the multilayer sheet 10 on which the first substrate film 12 is provided (semi-cutting surface 10C) in such a way that the adhesive film 14 is also cut along with the first substrate film 12, up to the middle of the thickness direction of the multilayer sheet 10. At this time, the semi-cutting surface 10C is divided into a first region and a region other than the first region (second region) with the cut line formed by the cut as the boundary line. Figure 10 This is a diagram showing an example of a multi-layered sheet 10 after being partially cut. Figure 10 (a) is a top view showing an example of the case where the multilayer sheet 10 after being cut is viewed from the side of the half-cut surface 10C. Figure 10 (b) is Figure 10 The cross-sectional view between reference numerals B and C in (a).

[0036] exist Figure 10 In the example shown, the half-cut surface 10C of the half-cut multilayer sheet 10 is divided by a cutting line CL into a plurality of circular first regions 10R1 formed at equal intervals along the length direction (or transport direction) of the multilayer sheet 10, and regions other than the first regions 10R1 (second regions 10R2). Furthermore, the cutting line CL is formed to extend from the half-cut surface 10C to the interface between the adhesive film 14 and the second substrate film 16. In addition, the shape and size of the first regions 10R1 and the second regions 10R2 in the XY plane are appropriately selected according to the shape and structure of the final product manufactured after lamination and subsequent post-processing, as well as the content of the post-processing after lamination. For example, if the final product is a semiconductor device, the shape and size of the first region 10R1 can be set to a shape and size that basically corresponds to the semiconductor wafer, carrier wafer, etc.

[0037] Next, as Figure 11 As shown, a release tape 60 is attached to the half-cut surface 10C of the half-cut multilayer sheet 10. The placement of the release tape 60 is not particularly limited as long as it is attached to both the first region 10R1 and the second region 10R2. For example, as shown... Figure 11 As illustrated, the material can be pasted at the center of the width direction of the half-cut surface 10C in a manner where the length direction of the peeling tape 60 is parallel to the length direction of the multilayer sheet 10. Figure 1 In the lamination process shown, a release tape bonding method can be provided between the half-cut section HC and the release section P to continuously bond the release tape 60 to the half-cut surface 10C. The structure of the release tape bonding method is not particularly limited; for example, a pressure roller can be used to press and bond the adhesive surface of the release tape 60 supplied by a release tape 60 supply roller to the half-cut surface 10C. In this case, the pressure roller for bonding the release tape 60 is positioned on the lower surface side of the multilayer sheet 10 located between the half-cut section HC and the release section P. Furthermore, the adhesive force between the release tape 60 and the half-cut surface 10C is set to be much greater than the adhesive force between the individual films constituting the multilayer sheet 10.

[0038] If a multilayer sheet 10 with a release strip 60 attached is conveyed to the release section P, the multilayer sheet 10 is separated in the release section P as follows: Figure 12 The illustrated sheet body portion 10A1 (10A) and the sheet unwanted portion 10B1 (10B) are shown. At this time, (i) the second region peeling process and (ii) the first process (first substrate film peeling process) are performed simultaneously. That is, (i) for the second region 10R2, peeling occurs at the interface between the second substrate film 16 and the adhesive film 14. The peeled second substrate film 16 becomes a component on the sheet body portion 10A1 side, and the peeled adhesive film 14 and the first substrate film 12 together with the peeling strip 60 adhered to the surface (half-cut surface 10C) of the first substrate film 12 become components on the sheet unwanted portion 10B1 side. (ii) Furthermore, for the first region 10R1, peeling occurs at the interface between the adhesive film 14 and the first substrate film 12. The peeled second substrate film 16 and the adhesive film 14 become components on the sheet body 10A1 side, and the peeled first substrate film 12 together with the peeling strip 60 pasted on the surface (half-cut surface 10C) of the first substrate film 12 become components on the sheet unwanted portion 10B1 side.

[0039] Figure 12 This is a cross-sectional view showing the cross-sectional structure of the multilayer sheet 10 after it has been separated into a main sheet portion 10A1 and a non-main sheet portion 10B1 by the peeling section P in the first process. Figure 12 (a) indicates that will Figure 1 A cross-sectional view of the cross-sectional structure of the sheet body 10A1 (10A) at position L1, cut off at the center of its width direction. Figure 12 (b) indicates that Figure 1 A cross-sectional view of the cross-sectional structure of the sheet material at position L2, where part 10B1 (10B) is cut off at the center of its width direction. (See diagram below.) Figure 12As shown, the sheet main body portion 10A1 has a layer structure in which a second base film 16 and an adhesive film 14 composed only of a portion corresponding to the first region 10R1 are laminated in sequence. The unnecessary portion 10B1 of the sheet has the following layer structure: a first base film 12 and an adhesive film 14 composed only of a portion corresponding to the second region 10R2 are laminated in sequence, and a release tape 60 is pasted on the surface (half-cut surface 10C) of the first base film 12 on the side opposite to the side where the adhesive film 14 is provided.

[0040] Here, the peel strengths p1 and p2 satisfy the formula (A) "p1 < p2" as described above. Therefore, in the first step (first base film peeling step), for the first region 10R1, among the interfaces formed between the films constituting the multi-layer sheet 10, peeling occurs at the interface with the lowest peel strength (the interface between the first base film 12 and the adhesive film 14). On the other hand, for the second region 10R2, Figure 1 Before the start of the continuous laminating process shown, initial setting is performed in advance so that peeling automatically occurs at the interface between the adhesive film 14 and the second base film 16 regardless of whether the formula (A) is satisfied in the second region peeling step.

[0041] This initial setting is implemented as follows. First, Figure 1 Before the start of the continuous laminating process shown, the interface between the adhesive film 14 and the second base film 16 is forcibly peeled in advance manually at the peeling portion P, so as to be separated into a first sheet composed only of the second base film 16 and a second sheet composed of the laminate of the first base film 12 and the adhesive film 14. Then, the manually separated first sheet (second base film 16) is pulled and set at the position for performing subsequent processes such as the laminating portion R, and the manually separated second sheet (the laminate of the first base film 12 and the adhesive film 14) is pulled via the support roller 40 and set at a waste portion recovery roller not shown. After such initial setting, if the continuous laminating process is implemented, peeling can automatically and continuously occur at the interface between the adhesive film 14 and the second base film 16 in the second region 10R2 as per the initial setting during the laminating process at the peeling portion P.

[0042] In addition, after the initial setting and the start of the continuous laminating process, in order for the interface between the adhesive film 14 and the second base film 16 to automatically and continuously peel only in the second region 10R2 at the peeling portion P, the first region 10R1 and the second region 10R2 respectively need to satisfy the following conditions. (i) As Figure 10 illustrated in (a) of, the first region 10R1 is a non-continuous region (or multiple discrete and dispersed regions) in the length direction (transport direction) of the multi-layer sheet 10. (ii) As Figure 10As illustrated in (a), the second region 10R2 is a region that is continuous along the length direction (conveyance direction) of the multilayer sheet 10.

[0043] The sheet material 10B1, separated at the peeling section P, is supported by the support roller 40. Figure 1 It is conveyed to the right and finally wound onto a non-displayed recovery roller. Furthermore, the sheet body 10A1, separated at the peeling section P, is then... Figure 1 The laminating section R is conveyed. Then, near the entrance of the laminating section R, the laminating target component 200 is stacked on the surface of the adhesive film 14 corresponding to the first region 10R1 of the sheet body 10A1 to form a laminate. The laminate is heated and pressurized as it passes between a pair of pressure rollers 50 and 52 constituting the laminating section R, thereby obtaining a laminate. Thus, the second process (laminated body formation process) ends. Afterward, the obtained laminate is further subjected to predetermined post-processes according to the structure, shape, etc. of the final product.

[0044] <Second Process> In the second process, firstly, a semi-cutting process is performed on the multilayer sheet 10 in the semi-cutting section HC. The semi-cutting process performed in the second process is performed in the same way as the semi-cutting process performed in the first process. Thus, the desired result is obtained. Figure 10 The example is a semi-cut multilayer sheet 10.

[0045] The partially cut multilayer sheet 10 is directly fed to the peeling section P, where it is separated into layers as shown below. Figure 13 The illustrated sheet body portion 10A2 (10A) and the sheet unwanted portion 10B2 (10B) are shown. At this time, a second region peeling process is performed. That is, for the second region 10R2, peeling occurs at the interface between the second substrate film 16 and the adhesive film 14. The peeled second substrate film 16 becomes a component on the sheet body portion 10A2 side, and the peeled adhesive film 14 and the first substrate film 12 become components on the sheet unwanted portion 10B2 side.

[0046] Figure 13 This is a cross-sectional view showing the cross-sectional structure of the multilayer sheet 10 after it has been separated into a main sheet portion 10A2 and a non-main sheet portion 10B2 by the peeling section P in the second process. Figure 13 (a) indicates that will Figure 1 A cross-sectional view of the cross-sectional structure of the sheet body 10A2 (10A) at position L1 in the middle of its width direction, cut off at the center. Figure 13 (b) indicates that Figure 1 A cross-sectional view of the cross-sectional structure of the sheet material at position L2, where part 10B2 (10B) is cut at the center of its width direction. (See diagram below.) Figure 13As shown, the sheet main body portion 10A2 has a layer structure in which a second base film 16, an adhesive film 14 composed only of a portion corresponding to the first region 10R1, and a first base film 12 composed only of a portion corresponding to the first region 10R1 are laminated in sequence. The sheet unnecessary portion 10B2 has a layer structure in which a first base film 12 composed only of a portion corresponding to the second region 10R2 and an adhesive film 14 composed only of a portion corresponding to the second region 10R2 are laminated in sequence.

[0047] Here, the peel strengths p1 and p2 satisfy the formula (A) "p1 < p2" as described above. However, for the second region 10R2, prior to the start of the continuous lamination process shown, initial setting is performed so that peeling automatically occurs at the interface between the adhesive film 14 and the second base film 16 regardless of whether the formula (A) is satisfied in the peeling process of the second region. This initial setting is the same as the initial setting in the first process. Figure 1 The sheet unnecessary portion 10B2 separated at the peeling portion P is conveyed in the right direction in

[0048] with the support roller 40 as a fulcrum and is finally wound around an unnecessary portion recovery roller not shown. Figure 1 On the other hand, while the sheet main body portion 10A2 separated at the peeling portion P is being conveyed to the lamination portion R in

[0049] it, a peeling tape 60 is pasted on the half-cut surface 10C (first region 10R1). As long as the peeling tape 60 is pasted on the half-cut surface 10C (first region 10R1), its pasting position is not particularly limited. For example, as Figure 1 illustrated, it can be pasted at the center in the width direction of the half-cut surface 10C (first region 10R1) such that the length direction of the peeling tape 60 is parallel to the length direction (conveying direction) of the sheet main body portion 10A2. In the Figure 14 lamination process shown, a peeling tape pasting means for continuously pasting the peeling tape 60 on the half-cut surface 10C (first region 10R1) can be provided between the position L1 and the lamination portion R. The structure of the peeling tape pasting means is not particularly limited. For example, a pressing roller that presses and pastes the adhesive surface of the peeling tape 60 supplied from the peeling tape supply roller onto the half-cut surface 10C (first region 10R1) can be cited. In this case, the pressing roller for pasting the peeling tape 60 is arranged on the lower surface side of the sheet main body portion 10A2 located between the position L1 and the lamination portion R. In addition, the adhesion force between the peeling tape 60 and the half-cut surface 10C (first region 10R1) is set to be much greater than the adhesion force between the films constituting the sheet main body portion 10A2. Figure 1 Furthermore, the sheet main body portion 10A2 pasted with the peeling tape 60 is further conveyed to

[0050] In addition, the sheet main body portion 10A2 pasted with the peeling tape 60 is further conveyed to Figure 1During the conveying of the laminating section R, the peeling belt 60 is directed in a direction intersecting the conveying direction (X2 direction) of the sheet body section 10A2 (e.g., Figure 1 Pulling the strip 60 (in the lower right direction) peels it off from the sheet body 10A2 while it is integrated with the first substrate film 12. This completes the first process (first substrate film peeling process). Furthermore, the means of performing the first process (first substrate film peeling process) is not particularly limited; for example, a device with a... Figure 1 The illustrated peeling section P has a substantially the same structure. Furthermore, the first substrate film 12, which is peeled off from the sheet body 10A2 while integrated with the peeling belt 60, is finally wound onto a substrate film recycling roller (not shown).

[0051] Furthermore, in the first process (first substrate film peeling process), at the interface between the films constituting the sheet body 10A2, peeling occurs at the interface between the first substrate film 12 and the adhesive film 14, where the peel strength is relatively weak. Therefore, with this interface as the peeling interface, the sheet body 10A2 with the peeling tape 60 attached is separated into two parts.

[0052] For reference only. Figure 15 The cross-sectional structure of the sheet body portion 10A2' (10A) obtained by performing a first process (first substrate film peeling process) on the sheet body portion 10A2 is shown. Figure 15 As shown, the sheet body 10A2' has a similar structure to... Figure 12 It has the same cross-sectional structure as the sheet body 10A1 shown in (a).

[0053] The sheet body 10A2', having had the first substrate film 12 peeled off after the first process (first substrate film peeling process), is then directed towards... Figure 1 The laminating section R is conveyed. Then, near the entrance of the laminating section R, the laminating target component 200 is stacked on the surface of the adhesive film 14 corresponding to the first region 10R1 of the sheet body 10A2' to form a laminate. The laminate is heated and pressurized as it passes between a pair of pressure rollers 50 and 52 constituting the laminating section R, thereby obtaining a laminate. Thus, the second process (laminated body formation process) ends. Afterward, the obtained laminate is further subjected to predetermined post-processes according to the structure, shape, etc. of the final product.

[0054] <The Occurrence Modes and Causes of Defective Peeling in the First and Second Processes> The descriptions of the first and second processes above assume that the processes are carried out under ideal conditions where no peeling defects occur. However, when the inventors actually tested the first and second processes, they confirmed that peeling defects (excessive peeling) as described in (a) and (b) below occurred.

[0055] (a) The following peeling defect (insufficient peeling) occurred: In the first process, when performing the second-region peeling process at the peeling portion P, for the second region 10R2, the interface between the adhesive film 14 and the second base film 16 could not be cleanly peeled, and a part or all of the adhesive film 14 adhered to the second base film 16 constituting the sheet main body portion 10A1 and remained. (b) The following peeling defect (insufficient peeling) occurred: In the second process, when performing the second-region peeling process at the peeling portion P, for the second region 10R2, the interface between the adhesive film 14 and the second base film 16 could not be cleanly peeled, and a part or all of the adhesive film 14 adhered to the second base film 16 constituting the sheet main body portion 10A2 and remained.

[0056] For reference, Figure 16 An example of the cross-sectional structure of a cut surface obtained by cutting the sheet main body portion 10A where a peeling defect (insufficient peeling) occurred at the central portion in the width direction is shown. Here, Figure 16 (a) is a cross-sectional view showing an example of the sheet main body portion 10A1 where a peeling defect (insufficient peeling) occurred in the first process, Figure 16 (b) is a cross-sectional view showing an example of the sheet main body portion 10A2 where a peeling defect (insufficient peeling) occurred in the second process. From the comparison with Figure 12 (a) and Figure 13 (a), it is also clear that for the Figure 16 shown sheet main body portions 10A1 and 10A2, the adhesive film 14 that should not originally exist in the second region 10R2 adhered to the second base film 16 and remained.

[0057] As the main reason for the occurrence of the peeling defect (insufficient peeling) as Figure 16 exemplified, the following reasons can be considered. "Even if it is initially set to pre-peel the interface between the second base film 16 and the adhesive film 14 in the second region 10R2, since the peeling strength p2 is relatively greater than the peeling strength p1, after the start of the lamination process, the adhesive film 14 easily adheres to the second base film 16 side during the second-region peeling process."

[0058] On the other hand, if it is considered that the main cause of the above peeling defect (insufficient peeling) is that the peeling strengths p1 and p2 satisfy the formula (A) "p1 < p2", then in order to suppress the occurrence of the peeling defect (insufficient peeling), it is sufficient to make the peeling strengths p1 and p2 satisfy the formula (B) "p1 > p2" or the formula (C) "p1 = p2". Therefore, the inventors used the multi-layer sheet 10 that satisfies the formula (B) or (C) instead of the multi-layer sheet 10 that satisfies the formula (A) to perform the lamination process in the first process and the second process.

[0059] As a result, when using the multilayer sheet 10 that satisfies formula (B), the aforementioned peeling defects (excessive peeling) are significantly suppressed. This is believed to be because, in the case of formula (B), the adhesive film 14 is more firmly bonded to the first substrate film 12 side compared to the second substrate film 16 side. Therefore, in the second region peeling process, peeling is very likely to occur continuously in the second region 10R2 at the interface between the second substrate film 16 and the adhesive film 14 (the interface with the weakest peel strength), just as stably as initially set. However, when using the multilayer sheet 10 that satisfies formula (B), in the first process (first substrate film peeling process) performed on the first region 10R1, a new peeling defect (excessive peeling) as shown in (c) and (d) below was confirmed to occur.

[0060] (c) The following peeling failure (over-peeling) occurs: In the first process, for the first region 10R1, not only is the first substrate film 12 (the original object to be peeled) peeled from the multilayer sheet 10, but the adhesive film 14 is also peeled from the multilayer sheet 10 as an integral part of the first substrate film 12. (d) The following peeling failure (over-peeling) occurs: In the second process, for the first region 10R1, not only is the first substrate film 12 (the original object to be peeled) peeled from the sheet body 10A2, but the adhesive film 14 is also peeled from the sheet body 10A2 as an integral part of the first substrate film 12.

[0061] For reference only. Figure 17 An example of a cross-sectional structure of a cut surface taken at the center of the width direction of a sheet body 10A that has experienced poor peeling (excessive peeling). Here, Figure 17 (a) is a cross-sectional view of an example of sheet body 10A1 where poor peeling (excessive peeling) occurred in the first process. Figure 17 (b) is a cross-sectional view showing an example of sheet body 10A2' where poor peeling (over-peeling) occurred in the second process. According to... Figure 12 (a) and Figure 15 The comparison also clearly shows that, for Figure 17 The adhesive film 14 in the sheet body 10A1 and 10A2' shown is missing from the first region 10R1, where it should be present.

[0062] As it occurs Figure 17 The main reasons for the poor peeling (over-peeling) illustrated can be considered as follows. "Since the peel strength p1 is relatively greater than the peel strength p2, the adhesive film 14 is more firmly bonded to the first substrate film 12 side compared to the second substrate film 16 side. Therefore, the result is that in the first process (first substrate film peeling process) performed on the first region 10R1, not only is the first substrate film 12 (the original object to be peeled) easily peeled off, but the adhesive film 14 is also easily peeled off as a whole with the first substrate film 12."

[0063] Furthermore, when using the multilayer sheet 10 that satisfies formula (C), it was confirmed that... Figure 16 The illustrated poor peeling (too small peeling) and Figure 17 The illustrated poor peeling (over-peeling) mixture occurs. It is believed that this is because equation (C) represents an intermediate characteristic between equation (A) and equation (B).

[0064] As explained above, when lamination is performed using a multilayer sheet 10 with a conventional three-layer structure, poor peeling occurs in either the first process or the second process, as shown in (1) and (2) below. (1) Defective peeling that occurs during the second zone peeling process ( Figure 16 (Example of excessively small peeling) (2) Delamination occurring in the first process (first substrate film peeling process) Figure 17 (Excessive stripping as illustrated)

[0065] Therefore, based on the above insights, the inventors discovered the multilayer sheet of the present embodiment described below.

[0066] (The multilayer sheet in this embodiment) The multilayer sheet of this embodiment includes a first substrate film, an adhesive film, a second substrate film and a third substrate film. The multilayer sheet is composed of the first substrate film, the adhesive film, the second substrate film and the third substrate film stacked in sequence, and satisfies the following formula (1). Equation (1) P1 <P2<P3

[0067] Here, in formula (1), P1 represents the peel strength between the first substrate film and the adhesive film (N / 250mm), P2 represents the peel strength between the adhesive film and the second substrate film (N / 250mm), and P3 represents the peel strength between the second substrate film and the third substrate film (N / 250mm).

[0068] The multilayer sheet of this embodiment is a four-layer structure in which a third substrate film is newly provided on the second substrate film 16 side, compared to the conventional three-layer multilayer sheet 10, and satisfies equation (1). Therefore, the two types of peeling defects mentioned above can be significantly suppressed. Figure 16 The example of excessively small peel and Figure 17The exemplified excessive peeling).

[0069] Further, according to Equation (1), in the multi-layer sheet of the present embodiment, the ratio of the peel strengths of two interfaces adjacent in the thickness direction is 1.0 < P2 / P1 and 1.0 < P3 / P2. However, when P2 / P1 and P3 / P2 are too close to 1.0, it is difficult to intentionally and reproducibly cause peeling at any of the three interfaces. Therefore, P2 / P1 is preferably 1.1 or more, more preferably 1.2 or more, and further preferably 1.3 or more. In addition, P3 / P2 is also preferably 1.1 or more, more preferably 1.2 or more, and further preferably 1.3 or more.

[0070] Next, the details of the case of performing a lamination process including a semi-cutting process and a second region peeling process using the multi-layer sheet of the present embodiment will be described with reference to the drawings. In addition, in the following description of the components and parts of the multi-layer sheet constituting the present embodiment and the sheet main body part and the unnecessary sheet part obtained by separating the multi-layer sheet into two, components and parts having the same or similar relationships in terms of function, material, or arrangement position as those of the conventional multi-layer sheet 10 are given the same or similar reference numerals as the components and parts in the multi-layer sheet 10. In addition, for reference, in Figure 2 and other drawings, for the multi-layer sheet, the sheet main body part, and the unnecessary sheet part of the present embodiment, each film is marked corresponding to its elastic modulus Q1, R, Q2, Q3 as needed. In addition, the interfaces between the films are marked corresponding to the peel strengths P1, P2, P3.

[0071] Figure 2 is a cross-sectional view showing an example of the cross-sectional structure of the multi-layer sheet of the present embodiment. The multi-layer sheet 100 of the present embodiment is a sheet having a four-layer structure in which a first base film 12, an adhesive film 14, a second base film 16, and a third base film 18 are laminated in sequence. Near the entrance of the semi-cutting part HC ( Figure 1 near the right side of the semi-cutting part HC in), the multi-layer sheet 100 is as Figure 2 shown, and the first base film 12 is located on the lower surface side.

[0072] When performing a lamination process using the multi-layer sheet 100 of the present embodiment, it can also be applied in the same manner as the conventional multi-layer sheet 10 Figure 1The lamination process is shown. Here, the outline of the conveying path of the multilayer sheet 100 in this embodiment during lamination is as follows. First, the multilayer sheet 100, supplied by a multilayer sheet supply roller (not shown), is conveyed from the right side to the half-cutting section HC in the figure, where it is half-cut. Next, the half-cut multilayer sheet 100 is further conveyed to the left side to reach the peeling section P. Then, at the peeling section P, a portion of the multilayer sheet 100 is peeled off from the multilayer sheet 100, thereby separating it into a sheet body portion 100A and a sheet unwanted portion 100B. Then, the sheet body portion 100A is further conveyed to the left side from the peeling section P and moves towards the lamination section R. The sheet body portion 100A moving towards the lamination section R forms a laminate of the sheet body portion 100A and the lamination target component 200, which is heated and pressurized in the lamination section R to obtain a laminate. Thus, the lamination process ends. Then, various post-processing steps are performed on the laminate according to the shape and structure of the final product. On the other hand, the unwanted portion 100B of the sheet is temporarily conveyed to the lower right from the peeling section P, and is further conveyed to the right, and is finally wound onto the unwanted portion recovery roller (not shown).

[0073] When laminating using the multilayer sheet 100 of this embodiment, as with laminating using the conventional multilayer sheet 10, each process can be performed in two modes (first process or second process). The first process and the second process will be described in detail below.

[0074] <First Process> In the first process, a semi-cutting process is first performed on the multilayer sheet 100 in the semi-cutting section HC. In the semi-cutting process, the multilayer sheet 100 is partially cut from the side of the multilayer sheet 100 on which the first substrate film is provided (semi-cutting surface 10C) in such a way that the first substrate film 12, the adhesive film 14 and the second substrate film 16 are cut to the middle of the thickness direction of the multilayer sheet 100. At this time, the semi-cutting surface 10C is divided into a first region and a region other than the first region (second region) with the cut line formed by the cut as the boundary line. Figure 3 This is a diagram showing an example of a multi-layered sheet 100 after being partially cut. Figure 3 (a) is a top view showing an example of the case where the multilayer sheet 100 after being cut is viewed from the side of the half-cut surface 10C. Figure 3 (b) is Figure 3 The cross-sectional view between reference numerals AA in (a) of the figure.

[0075] exist Figure 3 In the example shown, the cut line CL provided on the multilayer sheet 100, except that it is formed to extend from the half-cut surface 10C to the interface between the second substrate film 16 and the third substrate film 18, is similar to... Figure 10The example shown is formed similarly. Next, the peeling tape 60 is applied to the conventional multi-layer sheet 10 after it has been cut in half ( Figure 11 Similarly, such as Figure 4 As shown, a peeling tape 60 is attached to the half-cut surface 10C of the multilayer sheet 100 of this embodiment after half-cutting.

[0076] If a multilayer sheet 100 with a release strip 60 attached is conveyed to the release section P, the multilayer sheet 100 is separated in the release section P into the following sections: Figure 5 The illustrated sheet body portion 100A1 (100A) and the sheet unwanted portion 100B1 (100B) are shown. At this time, (i) the second region peeling process and (ii) the first process (first substrate film peeling process) are performed simultaneously. That is, (i) for the second region 10R2, peeling occurs at the interface between the third substrate film 18 and the second substrate film 16. The peeled third substrate film 18 becomes a component on the sheet body portion 100A1 side, and the peeled second substrate film 16, adhesive film 14, and first substrate film 12, together with the peeling strip 60 adhered to the surface (half-cut surface 10C) of the first substrate film 12, become components on the sheet unwanted portion 10B1 side. (ii) Furthermore, for the first region 10R1, peeling occurs at the interface between the adhesive film 14 and the first substrate film 12. The peeled third substrate film 18, the second substrate film 16 and the adhesive film 14 become the components on the sheet body portion 100A1 side. The peeled first substrate film 12 together with the peeling strip 60 pasted on the surface (half-cut surface 10C) of the first substrate film 12 become the components on the sheet unwanted portion 100B1 side.

[0077] Figure 5 This is a cross-sectional view showing the cross-sectional structure of the multilayer sheet 100 after it has been separated into a main sheet portion 100A1 and a non-main sheet portion 100B1 by the peeling section P in the first process. Figure 5 (a) indicates that will Figure 1 A cross-sectional view of the cross-sectional structure of the sheet body 100A1 (100A) at position L1 in the middle of its width direction, showing the cut surface. Figure 5 (b) indicates that Figure 1 A cross-sectional view of the cross-sectional structure of the sheet material at position L2, where part 100B1 (100B) is cut at the center of its width direction. (See diagram below.) Figure 5As shown, the sheet main body portion 100A1 has a layer structure in which a third base film 18, a second base film 16 composed only of a portion corresponding to the first region 10R1, and an adhesive film 14 composed only of a portion corresponding to the first region 10R1 are laminated in sequence. The unnecessary portion 100B1 of the sheet has the following layer structure: a first base film 12, an adhesive film 14 composed only of a portion corresponding to the second region 10R2, and a second base film 16 composed only of a portion corresponding to the second region 10R2 are laminated in sequence, and a release tape 60 is pasted on the surface (half-cut surface 10C) of the first base film 12 on the side opposite to the side where the adhesive film 14 is provided.

[0078] Here, the peel strengths P1, P2, and P3 satisfy the formula (1) "P1 < P2 < P3" as described above. Therefore, in the first step (first base film peeling step), for the first region 10R1, among the interfaces formed between the respective films constituting the multilayer sheet 100, peeling occurs at the interface with the minimum peel strength (the interface between the first base film 12 and the adhesive film 14). On the other hand, for the second region 10R2, before the start of the continuous lamination process shown in Figure 1 initial setting is performed in advance so that peeling automatically occurs at the interface between the second base film 16 and the third base film 18 in the second region peeling step.

[0079] This initial setting is carried out as follows. First, before the start of the continuous lamination process shown in Figure 1 the interface between the second base film 16 and the third base film 18 is manually and forcibly peeled in advance at the peeling portion P, so as to be separated into a first sheet composed only of the third base film 18 and a second sheet composed of a laminate in which the first base film 12, the adhesive film 14, and the second base film 16 are laminated in sequence. Then, the manually separated first sheet (third base film 18) is pulled and set at a position for performing subsequent steps such as the lamination portion R, and the manually separated second sheet (the laminate in which the first base film 12, the adhesive film 14, and the second base film 16 are laminated in sequence) is pulled and set at a non-illustrated unnecessary portion recovery roller via the support roller 40. After such initial setting is performed, if the continuous lamination process is carried out, peeling can automatically and continuously occur at the interface between the second base film 16 and the third base film 18 in the second region 10R2 as per the initial setting during the lamination process at the peeling portion P.

[0080] In addition, after the initial setting is performed and the continuous lamination process is started, in order for the interface between the second base film 16 and the third base film 18 to automatically and continuously occur only in the second region 10R2 at the peeling portion P, the first region 10R1 and the second region 10R2 respectively need to satisfy the following conditions. (i)As Figure 3As illustrated in (a), the first region 10R1 is a region that is discontinuous (or a plurality of discrete regions) along the length (conveyance direction) of the multilayer sheet 100. (ii) such as Figure 3 As illustrated in (a), the second region 10R2 is a region that is continuous along the length direction (conveyance direction) of the multilayer sheet 100.

[0081] In the peeling section P, the sheet material 100B1, which is not in the peeling section, is supported by the support roller 40 as the fulcrum. Figure 1 It is conveyed to the right and finally wound onto a non-displayed recovery roller. Furthermore, the sheet body 100A1, separated at the peeling section P, is then... Figure 1 The laminating section R is conveyed. Then, near the entrance of the laminating section R, the laminating target component 200 is stacked on the surface of the adhesive film 14 corresponding to the first region 10R1 of the sheet body 100A1 to form a laminate. The laminate is heated and pressurized as it passes between a pair of pressure rollers 50 and 52 constituting the laminating section R, thereby obtaining a laminate. Thus, the second process (laminated body formation process) ends. Afterward, a predetermined post-process is performed on the obtained laminate according to the structure, shape, etc. of the final product.

[0082] <Second Process> In the second process, firstly, a semi-cutting process is performed on the multilayer sheet 100 in the semi-cutting section HC. The semi-cutting process performed in the second process is performed in the same way as the semi-cutting process performed in the first process. Thus, the desired result is obtained. Figure 3 The example is a semi-cut multilayer sheet 100.

[0083] The semi-cut multi-layer sheet 100 is directly conveyed to the peeling section P, where it is separated into layers as shown below. Figure 6 The illustrated sheet body portion 100A2 (100A) and the sheet unwanted portion 100B2 (100B) are shown. At this time, a second region peeling process is performed. That is, for the second region 10R2, peeling occurs at the interface between the third substrate film 18 and the second substrate film 16. The peeled third substrate film 18 becomes a component on the sheet body portion 100A2 side, and the peeled second substrate film 16, adhesive film 14, and first substrate film 12 become components on the sheet unwanted portion 100B2 side.

[0084] Figure 6 This is a cross-sectional view showing the cross-sectional structure of the multilayer sheet 100 after it has been separated into a main sheet portion 100A2 and a non-main sheet portion 100B2 by the peeling section P in the second process. Figure 6 (a) indicates that will Figure 1Cross-sectional view of the cross-sectional structure of the sheet main body portion 100A2 (100A) at position L1 in [reference] cut at the central portion in its width direction Figure 6 (b) of [reference] shows Figure 1 Cross-sectional view of the cross-sectional structure of the unnecessary sheet portion 100B2 (100B) at position L2 in [reference] cut at the central portion in its width direction. As Figure 6 shown, the sheet main body portion 100A2 has a layer structure in which a third base film 18, a second base film 16 composed only of the portion corresponding to the first region 10R1, an adhesive film 14 composed only of the portion corresponding to the first region 10R1, and a first base film 12 composed only of the portion corresponding to the first region 10R1 are laminated in sequence. The unnecessary sheet portion 100B2 has a layer structure in which a first base film 12 composed only of the portion corresponding to the second region 10R2, an adhesive film 14 composed only of the portion corresponding to the second region 10R2, and a second base film 16 composed only of the portion corresponding to the second region 10R2 are laminated in sequence.

[0085] Here, the peel strengths P1, P2, and P3 satisfy the formula (1) "P1 < P2 < P3" as described above. However, for the second region 10R2, an initial setting is made in advance before the start of the continuous lamination process shown in Figure 1 such that peeling automatically occurs at the interface between the second base film 16 and the third base film 18 regardless of whether the formula (1) is satisfied in the peeling process of the second region. This initial setting is the same as the initial setting in the first process.

[0086] The unnecessary sheet portion 100B2 separated at the peeling portion P is conveyed in the right direction in [reference] with the support roller 40 as a fulcrum, and finally wound around an unnecessary portion recovery roller (not shown). Figure 1 On the other hand, the sheet main body portion 100A2 separated at the peeling portion P is conveyed to the lamination portion R in [reference], and a peeling tape 60 is pasted on the half-cut surface 10C (first region 10R1). As long as the peeling tape 60 is pasted on the half-cut surface 10C (first region 10R1), its pasting position is not particularly limited, and it is the same as the case of pasting the peeling tape 60 on the sheet main body portion 10A2 obtained by separating the conventional multi-layer sheet 10 at the peeling portion P (

[0087] ). Similarly, as Figure 1 shown, the peeling tape 60 is pasted on the half-cut surface 10C (first region 10R1) of the sheet main body portion 100A2. Figure 14 Figure 7

[0088] In addition, the sheet main body portion 100A2 pasted with the peeling tape 60 is further conveyed to Figure 1 ​​During the conveying of the laminating section R, the peeling belt 60 is directed in a direction that intersects with the conveying direction (X2 direction) of the sheet body section 100A2 (e.g., Figure 1 Pulling the strip 60 (in the lower right direction), the stripping strip 60 is peeled off from the sheet body 100A2 while integrated with the first substrate film 12. This completes the first process (first substrate film peeling process). Then, the first substrate film 12, peeled off from the sheet body 100A2 while integrated with the stripping strip 60, is finally wound onto a substrate film recycling roller (not shown).

[0089] Furthermore, in the first process (first substrate film peeling process), at the interface between the films constituting the sheet body 100A2, peeling occurs at the interface between the first substrate film 12 and the adhesive film 14, where the peel strength is relatively weakest. Therefore, with this interface as the peeling interface, the sheet body 100A2 with the peeling tape 60 attached is separated into two parts.

[0090] For reference only. Figure 8 The cross-sectional structure of the sheet body 100A2' (100A) obtained by performing a first process (first substrate film peeling process) on the sheet body 100A2 is shown. Figure 8 As shown, the sheet body 100A2' has the same as Figure 5 It has the same cross-sectional structure as the sheet body 100A1 shown in (a).

[0091] The sheet body 100A2', having had the first substrate film 12 peeled off after the first process (first substrate film peeling process), is then directed to... Figure 1 The laminating section R is conveyed. Then, near the entrance of the laminating section R, the laminating target component 200 is stacked on the surface of the adhesive film 14 corresponding to the first region 10R1 of the sheet body 100A2' to form a laminate. The laminate is heated and pressurized as it passes between a pair of pressure rollers 50 and 52 constituting the laminating section R, thereby obtaining a laminate. Thus, the second process (laminated body formation process) ends. Afterward, a predetermined post-process is performed on the obtained laminate according to the structure, shape, etc. of the final product.

[0092] <Laminated Material Manufacturing Method> The above description uses the accompanying drawings to illustrate a specific example of the lamination process of the multilayer sheet 100 using this embodiment. However, as long as the lamination process of the multilayer sheet 100 using this embodiment (in other words, the method of manufacturing the laminate) includes at least the half-cutting process, the second region peeling process, the first process, and the second process described below, the implementation is not limited to the specific example described above (the first process and the second process).

[0093] Semi-cutting process: The process involves partially cutting the multilayer sheet 100 from the side of the multilayer sheet 100 where the first substrate film 12 is disposed (half-cut surface 10C) in such a way that the first substrate film 12, the adhesive film 14, and the second substrate film 16 are cut to the middle of the thickness direction of the multilayer sheet 100, while the side of the multilayer sheet 100 where the first substrate film 12 is disposed (half-cut surface 10C) is cut into a first region 10R1 and a region other than the first region 10R1, namely a second region 10R2, with the cutting line CL formed by the cutting as the boundary line.

[0094] Second-zone stripping process: For the second region 10R2, a peeling process is performed at the interface between the second substrate film 16 and the third substrate film 18.

[0095] First step: For the first region 10R1, a peeling process is performed at the interface between the first substrate film 12 and the adhesive film 14.

[0096] Second step: The process of forming a laminate by heating and pressurizing the laminate is a laminate obtained by attaching the laminated object component 200 to the surface of the adhesive film 14 of the sheet body portions 100A1 and 100A2' (sheets on one side of the third substrate film 18 and in the first region 10R1 where the second substrate film 16 and the adhesive film 14 are sequentially laminated). The sheet body portions 100A1 and 100A2' are one of two sheets obtained by separating the multilayer sheet 100 into two in its thickness direction by at least a second region peeling process and a first process.

[0097] Here, regarding the execution order of the second region peeling process and the first process, the second region peeling process and the first process can be performed substantially simultaneously, as in the first process, or the first process can be performed after the second region peeling process, as in the second process. Furthermore, the planar shape of the multilayer sheet 100 used in the laminate manufacturing method of this embodiment is not particularly limited and can be appropriately selected according to the implementation of the lamination process. For example, if the lamination process is as follows... Figure 1 The exemplified continuous process can be as follows: Figure 1 and Figure 2 The strip-shaped sheet shown in the example, which is long in the length direction, can also be a square or strip-shaped sheet with a length-to-width ratio of about 1:3 to 3:1 if the lamination process is a single-sheet (leaf-type) process.

[0098] Furthermore, the planar shape of the first region 10R1 can be appropriately selected based on the shape and structure of the manufactured laminate and the final product, for example, it can be circular, approximately circular, or polygonal. Additionally, when the multilayer sheet 100 used in the lamination process is a strip sheet, the planar shape of the first region 10R1 can be a single continuous region along the length of the strip multilayer sheet 100, but it is generally preferred to have multiple regions arranged along the length of the strip multilayer sheet 100 (e.g., multiple circular or approximately circular regions). Furthermore, the lamination target component 200 constituting the laminate can be selected based on various subsequent processes performed after the manufacturing method of the laminate of this embodiment, and the shape and structure of the final product manufactured after these subsequent processes; for example, semiconductor wafers, glass wafers (glass carrier substrates), etc., can be used.

[0099] <Post-processing of laminates> As described above, the subsequent processes performed on the laminate obtained by the first or second process are appropriately determined based on the structure, shape, etc., of the final product. However, when the final product is a semiconductor device, for the laminate, for example after the second process (laminate formation process), various processes required for manufacturing a semiconductor device (e.g., electrode formation process, mounting process, molding process, polishing process, wiring formation process, etc.) are performed on the laminate obtained by separating the laminate at the interface between the adhesive film 14 and the second substrate film 16. In this case, the laminated component 200 uses glass wafers (glass carrier substrates), semiconductor wafers, etc., depending on the semiconductor device manufacturing process.

[0100] <Details about multi-layer sheets> Next, the details of each film constituting the multilayer sheet 100 of this embodiment, suitable characteristic values, etc., will be described below.

[0101] In this embodiment, the multilayer sheet 100 satisfies equation (1), and more preferably satisfies equation (2). Equation (2) Q2 / Q3≤2.0 In addition, in equation (2), Q2 represents the elastic modulus (MPa) of the second substrate film and Q3 represents the elastic modulus (MPa) of the third substrate film. Furthermore, in the following description, the elastic modulus (MPa) of the first substrate film is denoted as Q1, and the elastic modulus (MPa) of the adhesive film (in its uncured state) is denoted as R.

[0102] Compared to the conventional three-layer multilayer sheet 10, the multilayer sheet 100 of this embodiment satisfies Equation (1) by setting the number of film layers constituting the multilayer sheet 100 to four, thereby significantly suppressing the two types of peeling defects (over-peeling and under-peeling) that occur in the conventional three-layer multilayer sheet 10. However, with the four-layer structure, it was found that a new type of peeling defect occurs in the multilayer sheet 100 of this embodiment. This peeling defect is: in the second process (laminate formation process), a wrinkle occurs between the third substrate film 18 and the second substrate film 16 constituting the sheet body 100A, and from this wrinkle, an unintentional peeling defect occurs at the interface between the third substrate film 18 and the second substrate film 16 (hereinafter, this peeling defect is referred to as "peeling caused by wrinkles"). Therefore, the inventors have studied the cause of peeling caused by wrinkles. As can be seen from the results, in the second process, when tension is applied to the third substrate film 18 in its length direction, if the third substrate film 18 is too soft relative to the second substrate film 16, the third substrate film 18 will extend in the length direction, thereby causing wrinkles between the third substrate film 18 and the second substrate film 16, which become the cause of peeling due to wrinkles.

[0103] Therefore, based on the above insights, the inventors discovered that if formula (2) is satisfied, the occurrence of peeling caused by wrinkles can be significantly suppressed. Furthermore, from the viewpoint of further suppressing the occurrence of peeling caused by wrinkles, Q2 / Q3 is more preferably 1.35 or less, and more preferably 1.1 or less. On the other hand, the lower limit value of Q2 / Q3 is not particularly limited, but from the viewpoint of the ease of obtaining films that can be used as the second substrate film 16 and the third substrate film 18, practically it is preferably 0.2 or more, and more preferably 0.4 or more.

[0104] The elastic modulus R of the adhesive film 14 is not particularly limited, but if the elastic modulus R is too large, then... Figure 1 The lamination process shown is prone to self-destruction of the adhesive film 14, which may result in poor peeling. Therefore, the elastic modulus R of the adhesive film 14 is preferably 20 MPa or less, more preferably 10 MPa or less. Furthermore, the lower limit of the elastic modulus R is not particularly limited, but from a practical point of view, it is preferably 1.0 MPa or more, more preferably 0.5 MPa or more.

[0105] Furthermore, the peel strengths P1, P2, and P3 are not particularly limited as long as they satisfy formula (1). The peel strength P1 is preferably 0.1N / 250mm or more and less than 5N / 250mm, more preferably 0.1N / 250mm to 1N / 250mm, and even more preferably 0.1N / 250mm to 0.5N / 250mm. The peel strength P2 is preferably greater than 0.1N / 250mm and less than 5N / 250mm, more preferably greater than 0.5N / 250mm and less than 5N / 250mm, and even more preferably greater than 0.5N / 250mm and less than 1.5N / 250mm. The peel strength P3 is preferably 0.5N / 250mm to 15N / 250mm, more preferably 1N / 250mm to 10N / 250mm, and even more preferably greater than 1.5N / 250mm and less than 10N / 250mm. In addition, by making the peel strength P3 below 15N / 250mm, the second-zone peeling process can be carried out stably.

[0106] The multilayer sheet 100 of this embodiment has a layer structure in which a first substrate film 12, an adhesive film 14, a second substrate film 16, and a third substrate film 18 are sequentially stacked. Here, the thickness of each film 12, 14, 16, and 18 is fixed relative to the horizontal direction (XY direction), and they are not pre-cut (no cutting lines CL are provided to divide each film in the horizontal direction). Furthermore, the planar shape of the multilayer sheet 100 of this embodiment is not particularly limited and can be appropriately selected to suit the lamination process. For example, as... Figure 1 As illustrated, when lamination is performed in a continuous processing manner, the multilayer sheet 100 of this embodiment is typically used as a strip sheet. Furthermore, when lamination is performed in a batch processing manner, the multilayer sheet 100 of this embodiment is typically used as a square sheet with a aspect ratio of approximately 1:3 to 3:1.

[0107] Furthermore, the material, thickness, etc., of the first substrate film 12, adhesive film 14, second substrate film 16, and third substrate film 18 are not particularly limited as long as they satisfy formula (1) and the adhesive film 14 has adhesive properties and is cured during heat treatment. However, it is particularly suitable that these films 12, 14, 16, and 18 are the films described below.

[0108] First substrate film 12 Examples of materials constituting the first substrate film 12 include polyolefin resins such as polypropylene (PP) resin and polymethylpentene resin, polyester resins such as polyethylene terephthalate (PET) resin and polyethylene naphthalate resin, and resin materials such as polyimide resin and polyetherimide resin. The first substrate film 12 can be a single-layer film composed of only one type of resin material, or it can be a multilayer film composed of two layers of film. However, when the first substrate film 12 is composed of a multilayer film, the adhesive force between each film is set to be sufficiently large compared to the peel strengths P1, P2, and P3, so that when an external force such as the peeling portion P is applied to the multilayer sheet 100 in its thickness direction to divide it into two parts, the interfaces between the films constituting the first substrate film 12 with a multilayer structure do not peel off. Furthermore, it is preferable to use a release material or the like to perform a release treatment on the surface of the first substrate film 12 (at least the side that is in close contact with the adhesive film 14, or both sides). The thickness of the first substrate film 12 is not particularly limited, but from the viewpoints of cost, strength, and operability, it is preferably 15μm to 100μm, and more preferably 20μm to 50μm. In addition, as a release material, examples include silicone-based release materials, long-chain alkyl-based release materials, and fluorine-based release materials.

[0109] Adhesive film 14 The adhesive film 14 is a film that has adhesive properties and cures upon heat treatment, and is generally composed of a thermosetting resin composition. Examples of such thermosetting resin compositions include resin compositions containing epoxy resin, a curing agent, and inorganic fillers. Furthermore, the thermosetting resin composition constituting the adhesive film 14 may, as needed, contain a black pigment such as carbon. When using a black adhesive film 14 containing dispersed black pigment, in subsequent processes after lamination, the concealment of components (e.g., semiconductor elements) formed or disposed on one or the other side of the adhesive film 14 can be ensured, and laser marking can be performed on the cured layer of the adhesive film 14.

[0110] The thickness of the adhesive film 14 is not particularly limited, but from the viewpoint of ensuring sufficient adhesion and suppressing warping of the resulting laminate, it is preferably 1 μm to 50 μm, more preferably 10 μm to 50 μm, and even more preferably 15 μm to 40 μm. Furthermore, in subsequent processes after lamination, where concealment is required, from the viewpoint of ensuring concealment, the thickness of the black adhesive film 14 is preferably 10 μm or more.

[0111] When the thermosetting resin composition constituting the adhesive film 14 contains epoxy resin, curing agent and inorganic filler, and further contains black pigment as needed, the materials described below are suitable.

[0112] First, examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic varnish type epoxy resin, alicyclic epoxy resin, siloxane type epoxy resin, biphenyl type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, and epoxy resin containing naphthalene rings, etc., and two or more can be used in combination. Furthermore, based on adhesion, from the viewpoint of the reliability of the resulting laminate and the final product, it is preferable to use a combination of epoxy resin that is solid at room temperature and liquid epoxy resin. The content of epoxy resin in the thermosetting resin composition is not particularly limited, but from the viewpoint of ensuring sufficient adhesion to the laminated component 200 in the second step (laminate formation step), it is preferably 15 to 45 parts by mass relative to 100 parts by mass of the non-volatile component constituting the thermosetting resin composition.

[0113] Examples of curing agents for epoxy resins include imidazole-based, amine-based, and phosphorus-based curing agents. From the viewpoint of the storage stability and reactivity of the thermosetting resin composition constituting the adhesive film 14, it is preferable to use at least 2-phenyl-1-benzyl-1H-imidazolium, dicyandiamide, and other curing agents in combination. The content of the curing agent is not particularly limited, but is preferably 0.5 to 3 parts by weight relative to 100 parts by weight of the non-volatile components constituting the thermosetting resin composition. Furthermore, in this application specification, the term "curing agent" includes not only curing agents in the narrow sense but also compounds referred to as curing catalysts or curing accelerators.

[0114] Examples of inorganic materials constituting inorganic fillers include SiO2 (silicon dioxide), Al2O3 (alumina), AlN, and BN. From the viewpoint of reducing the coefficient of linear expansion, silicon dioxide is preferred, while from the viewpoint of improving thermal conductivity, alumina and BN are preferred. The content of the inorganic filler is not particularly limited, but from the viewpoint of suppressing warping of the resulting laminate, it is preferably 60 to 90 parts by mass relative to 100 parts by mass of the non-volatile component constituting the thermosetting resin composition. Particularly when the inorganic filler is silicon dioxide, it is more preferably 60 to 80 parts by mass, and when the inorganic filler is alumina or BN, it is more preferably 70 to 90 parts by mass.

[0115] Examples of black pigments include carbon and titanium, but carbon is preferred from the viewpoint of easily obtaining superior concealment. The content of the black pigment is not particularly limited, but from the viewpoint of easily ensuring concealment, it is preferably 0.05 to 3 parts by weight relative to 100 parts by weight of the non-volatile component of the thermosetting resin composition containing the black pigment.

[0116] Second substrate film 16 Examples of materials constituting the second substrate film 16 include polyolefin resins such as polypropylene resin and polymethylpentene resin, polyester resins such as polyethylene terephthalate resin and polyethylene naphthalate resin, polyimide resin, and polyetherimide resin. The second substrate film 16 can be a single-layer film composed of only one type of resin material, or it can be a multilayer film composed of two layers of film. However, when the second substrate film 16 is composed of multiple layers, the adhesive force between each film is set to be sufficiently large compared to the peel strengths P1, P2, and P3, so that when an external force, such as a peeling portion P, is applied to the multilayer sheet 100 in its thickness direction to divide it into two parts, the interfaces between the films constituting the second substrate film 16 with a multilayer structure do not peel off. The second substrate film 16 can be a single-layer film or a combination of two or more multilayer films. Furthermore, it is preferable to use a release material or the like to perform a demolding treatment on only one side of the second substrate film 16. In this case, when manufacturing the multilayer sheet 100, the surface of the second substrate film 16 that has undergone the demolding treatment is in close contact with the adhesive film 14. Furthermore, examples of demolding materials include silicone-based demolding materials, long-chain alkyl-based demolding materials, and fluorine-based demolding materials. The thickness of the second substrate film 16 is not particularly limited, but from the viewpoints of cost and processability, it is preferably 15μm to 100μm, and more preferably 20μm to 75μm.

[0117] Third substrate film 18 There are no particular limitations on the material and layer structure of the third substrate film 18. For example, it can have the same or similar material and layer structure as the second substrate film 16. From the viewpoint of easily satisfying equation (1), it is generally suitable to have a film with self-adhesive properties (pressure-sensitive adhesive film). In this case, the self-adhesive property is given to the side of the third substrate film 18 that is in close contact with the second substrate film 16. When the third substrate film 18 is composed of a pressure-sensitive adhesive film, the third substrate film 18 can contain a pressure-sensitive adhesive layer and a substrate layer. For example, a two-layer pressure-sensitive adhesive film with a pressure-sensitive adhesive layer and a substrate layer stacked in sequence can be cited. In addition, the adhesive force between the pressure-sensitive adhesive layer and the substrate layer is set to be large enough compared with the peel strength P1, P2, P3, so that when the peel portion P, etc., applies an external force to the multilayer sheet 100 in its thickness direction to divide it into two parts, the interfaces of each layer constituting the pressure-sensitive adhesive film do not peel off.

[0118] Preferably, the pressure-sensitive adhesive layer has pressure-sensitive adhesive force at room temperature and has the necessary adhesion to the adhered object, such as the second substrate film 16. Examples of materials constituting the pressure-sensitive adhesive layer include acrylic resins, various synthetic rubbers, natural rubbers, and polyimide resins.

[0119] Furthermore, as the substrate layer, known resin films such as polyester film, polytetrafluoroethylene film, polyethylene (PE) film, polypropylene film, and polymethylpentene film can be used. Among these, polyester film is preferred, and polyethylene terephthalate film is more preferred. In addition, the substrate layer can also be a laminated film of the two resin films listed above. However, the adhesive force between each resin film constituting the laminated film is set to be sufficiently large compared with the peel strength P1, P2, and P3, so that when an external force is applied to the multilayer sheet 100 in its thickness direction at the peel portion P, causing it to split into two parts, the interface between each resin film constituting the laminated film does not peel off.

[0120] Examples of pressure-sensitive adhesive films include PET-type pressure-sensitive adhesive films composed of a PET film and a pressure-sensitive adhesive layer disposed on at least one side of the PET film; EVA-type pressure-sensitive adhesive films composed of an EVA (ethylene-vinyl acetate copolymer) film and a pressure-sensitive adhesive layer disposed on at least one side of the EVA film; and OPP-type pressure-sensitive adhesive films composed of an OPP (biaxially oriented polypropylene) film and a pressure-sensitive adhesive layer disposed on at least one side of the OPP film. From the viewpoint of easily ensuring rigidity, PET-type pressure-sensitive adhesive films are preferred. Furthermore, the thickness of the pressure-sensitive adhesive film is not particularly limited. From the viewpoint of cost and preventing wrinkles when tension is applied in the horizontal direction of the multilayer sheet 100, a thickness of 25 μm to 100 μm is preferred, and from the viewpoint of operability, a thickness of 30 μm to 75 μm is more preferred.

[0121] Furthermore, when a semiconductor device is manufactured as a final product by further performing post-processing on the laminate made using the multilayer sheet 100 of this embodiment, the third substrate film 18 can also function as a back-side polishing belt.

[0122] Manufacturing method of multilayer sheet 100 The manufacturing method of the multilayer sheet 100 in this embodiment is not particularly limited, and it can be manufactured appropriately, for example, by the following sequence (i) and (ii). (i) First, a coating liquid for forming an adhesive film 14 is applied to one side of the first substrate film 12, and then dried to form the adhesive film 14. Next, a second substrate film 16 is bonded to the adhesive film 14, and then a third substrate film composed of a pressure-sensitive adhesive film is bonded to the second substrate film 16. (ii) First, a coating liquid for forming an adhesive film 14 is applied to one side of the second substrate film 16, and then dried to form the adhesive film 14. Next, the first substrate film 12 is bonded to the adhesive film 14, and a third substrate film composed of a pressure-sensitive adhesive film is bonded to the second substrate film 16.

[0123] Furthermore, the coating liquid used to form the adhesive film 14 is a solution in which the thermosetting resin composition constituting the adhesive film 14 is dissolved in a solvent and adjusted to have a viscosity suitable for coating. Moreover, there are no particular limitations on the method of coating using the coating liquid; for example, a roller coater can be used.

[0124] Applications of multi-layer sheet 100 The multilayer sheet 100 of this embodiment can be used in the same way as the conventional multilayer sheet 10 during lamination and subsequent processes to form a laminate, which can then be used to manufacture a final product. However, the multilayer sheet 100 of this embodiment is particularly suitable for use in the manufacture of various semiconductor devices as the final product. In this case, the laminated component 200 can be a glass substrate, a semiconductor wafer, or the like, depending on the semiconductor device manufacturing process. Example

[0125] The following examples illustrate specific examples of the present invention, but the present invention is not limited to the examples described below.

[0126] 1. Films and coating solutions used for manufacturing multilayer sheets The films and coating solutions used in the fabrication of the multilayer sheets in the various embodiments and comparative examples are those described below.

[0127] (1) First substrate film D-1: PET film with single-sided demolding treatment (pure water contact angle: 102°, 31B tape peel strength: 115mN / 25mm, thickness: 25μm, elastic modulus Q1: 3500MPa) D-2: PET film with single-sided demolding treatment (pure water contact angle: 115°, 31B tape peel strength: 275mN / 25mm, thickness: 25μm, elastic modulus Q1: 3500MPa) D-3: PP film with single-sided demolding treatment (pure water contact angle: 110°, 31B tape peel strength: 125mN / 25mm, thickness: 25μm, elastic modulus Q1: 1700MPa) D-4: PET film with single-sided demolding treatment (pure water contact angle: 89°, 31B peel strength: 4125mN / 25mm, thickness: 38μm, elastic modulus Q1: 3500MPa).

[0128] Here, "pure water contact angle" refers to the contact angle of the peel-treated surface of the first substrate film relative to pure water. Furthermore, "31B tape peel strength" refers to the peel strength obtained when a 31B tape (manufactured by Nitto Denko) is adhered to the peel-treated surface of the first substrate film and peeled at a peel speed of 300 mm / min and a peel angle of 180°. These points also apply to the second substrate film, which will be described later.

[0129] (2) Coating liquid used to form adhesive film C-1: A coating solution consisting of 76 parts by mass of a non-volatile component comprising the following components dissolved in 24 parts by mass of an organic solvent. • Non-volatile components: 30 parts by weight of epoxy resin, 1.2 parts by weight of curing agent, 0.8 parts by weight of carbon, and 68 parts by weight of silica filler. • The elastic modulus R of the film (20 μm thick) obtained by coating and drying the coating solution is 1.5 MPa.

[0130] C-2: A coating solution consisting of 86 parts by mass of a non-volatile component comprising the following components dissolved in 14 parts by mass of an organic solvent. • Non-volatile components: 23 parts by weight of epoxy resin, 1 part by weight of curing agent, and 76 parts by weight of silica filler. • The elastic modulus R of the film (20 μm thick) obtained by coating and drying the coating solution is 2.5 MPa.

[0131] C-3: A coating solution consisting of 87 parts by mass of a non-volatile component comprising the following components is dissolved in 13 parts by mass of an organic solvent. • Non-volatile components: 23.9 parts by weight of epoxy resin, 1 part by weight of curing agent, 0.1 parts by weight of carbon, and 75 parts by weight of silica filler. • The elastic modulus R of the film (20 μm thick) obtained by coating and drying the coating solution is 3.0 MPa.

[0132] C-4: A coating solution consisting of 89 parts by mass of a non-volatile component comprising the following components is dissolved in 11 parts by mass of an organic solvent. • Non-volatile components: 13.4 parts by weight of epoxy resin, 0.5 parts by weight of curing agent, 0.6 parts by weight of carbon, and 85.5 parts by weight of alumina filler. • The elastic modulus R of the film (20 μm thick) obtained by coating and drying the coating solution is 3.5 MPa.

[0133] (3) Second substrate film B-1: PET film with single-sided demolding treatment (pure water contact angle: 96°, 31B peel strength: 2313mN / 25mm, thickness: 38μm, elastic modulus Q2: 3500MPa) B-2: PET film with single-sided demolding treatment (pure water contact angle: 94°, 31B peel strength: 688mN / 25mm, thickness: 38μm, elastic modulus Q2: 3500MPa) B-3: PET film with single-sided demolding treatment (pure water contact angle: 96°, 31B peel strength: 2313mN / 25mm, thickness: 25μm, elastic modulus Q2: 3500MPa) B-4: PET film with single-sided demolding treatment (pure water contact angle: 89°, 31B peel strength: 4125mN / 25mm, thickness: 38μm, elastic modulus Q2: 3500MPa) B-5: PET film with single-sided demolding treatment (pure water contact angle: 73°, 31B tape peel strength: 7500mN / 25mm, thickness: 38μm, elastic modulus Q2: 3500MPa) B-6: PET film with single-sided demolding treatment (pure water contact angle: 102°, 31B tape peel strength: 115mN / 25mm, thickness: 25μm, elastic modulus Q2: 3500MPa) B-7: PP film with single-sided demolding treatment (pure water contact angle: 110°, 31B tape peel strength: 125mN / 25mm, thickness: 25μm, elastic modulus Q2: 1700MPa)

[0134] (4) Third substrate film A-1: A film with a pressure-sensitive adhesive layer on one side of a substrate layer (PET film) (180° peel strength of 188μm polyester: 0.17N / 25mm, total thickness: 50μm, elastic modulus Q3: 3500MPa). A-2: A film with a pressure-sensitive adhesive layer on one side of a substrate layer (PET film) (180° peel strength of 188μm polyester: 0.20N / 25mm, total thickness: 38μm, elastic modulus Q3: 3500MPa). A-3: A film with a pressure-sensitive adhesive layer on one side of a substrate layer (PET film) (180° peel strength of 188μm polyester: 0.49N / 25mm, total thickness: 50μm, elastic modulus Q3: 3500MPa). A-4: A film with a pressure-sensitive adhesive layer on one side of a substrate layer (PET film) (180° peel strength of 188μm polyester: 1.23N / 25mm, total thickness: 50μm, elastic modulus Q3: 3500MPa). A-5: A film with a pressure-sensitive adhesive layer on one side of a substrate layer (PET film) (180° peel strength of 188μm polyester: 0.08N / 25mm, total thickness: 50μm, elastic modulus Q3: 3500MPa). A-6: A film with a pressure-sensitive adhesive layer on one side of a substrate layer (PE film) (180° peel strength of 188μm polyester: 0.13N / 25mm, total thickness: 70μm, elastic modulus Q3: 1000MPa).

[0135] Here, "180° peel strength of 188μm polyester" refers to the peel strength when the polyester film (thickness: 188μm) is adhered to the side of the third substrate film with the pressure-sensitive adhesive layer using a roller, and after being left at room temperature for 30 minutes, it is peeled at a peel speed of 300mm / min and a peel angle of 180°.

[0136] 2. Fabrication of multi-layer sheets Next, as shown in Tables 1-3, the first substrate film, the coating liquid for the adhesive film, the second substrate film, and the third substrate film were combined to produce multilayer sheets for each embodiment and comparative example. Specifically, in producing the multilayer sheet, firstly, the coating liquid for the adhesive film was applied to one side (the side that underwent demolding treatment) of the first substrate film using a roller coater, and then dried to form an adhesive film (20 μm thick). Next, the second substrate film was bonded to the surface of the adhesive film. At this time, the demolded side of the second substrate film was bonded to the surface of the adhesive film. Then, the side of the third substrate film with the pressure-sensitive adhesive layer was bonded to the surface of the second substrate film, thereby producing a strip-shaped multilayer sheet.

[0137] 3. Evaluation Results For the multilayer sheets of each embodiment and comparative example, the types of films constituting these multilayer sheets, the characteristic values ​​of the multilayer sheets (peel strength, elastic modulus, etc.), and the results of the evaluation of peel defects are shown in Tables 1 to 3. Furthermore, the evaluation results of the concealment (L value) of the multilayer sheets of some embodiments are shown in Table 4. In addition, the evaluation methods for peel strength, elastic modulus, peel defects (processability, peelability, laminationability), and concealment (L value) shown in the tables are described in detail in the following four sections.

[0138] [Table 1]

[0139] [Table 2]

[0140] [Table 3]

[0141] [Table 4] 4. Evaluation Methods For the multilayer sheets of each embodiment and comparative example, peel strengths P1, P2, and P3 were measured, and the elastic modulus of each film constituting the multilayer sheet was also measured. Furthermore, using the multilayer sheets of each embodiment and comparative example, [the following was conducted]... Figure 1 The peeling defects during lamination of the continuous processing method shown are evaluated. These evaluation methods are described in detail below.

[0142] 4.1 Determination of peel strength (1) Determination of peel strength P1 Using test samples cut from multilayer sheets with a width of 250 mm and a length of 250 mm, the peel strength P1 was measured using an AUTOGRAGH (manufactured by Shimadzu Scientific, AUTOGRAGH AGS-X (load sensor: 5N)). During the measurement, on a flat sample stage, with one end of the test sample (where the side with the first substrate film is fixed to the top) at 0° along its length, the first substrate film was peeled at a peeling speed of 500 mm / min in a 180° direction (the other end) (i.e., at a peeling angle of 180°) starting from one end of the test sample. The peel strength at this point was then measured. The peel strength of five test samples was measured, and the average of the five measured strengths was taken as the peel strength P1.

[0143] (2) Determination of peel strength P2 The first substrate film is removed from the multilayer sheet, exposing the surface of the adhesive film. Next, to aid in the peeling of the second substrate film and the adhesive film at the interface, a PET film (thickness: 25 μm, without demolding treatment on both sides) for assisted peeling is laminated onto the exposed adhesive film surface using a laminator at a temperature of 80°C and a lamination speed of 0.3 m / min, resulting in a laminate. The resulting laminate is then cut into test samples with a width of 250 mm and a length of 250 mm, and the peel strength P2 is measured using Autogrig. During the measurement, on a flat sample stage, with one end of the test sample (where the side with the PET film for assisted peeling is fixed to the top) at 0° along its length, the two layers of film (the PET film for assisted peeling and the adhesive film) are peeled 180° (towards the other end) at a peeling speed of 500 mm / min, starting from one end of the test sample. The peel strength at this point is then measured. Peel strength was measured on 5 samples, and the average value of the 5 measured strengths was taken as the peel strength P2.

[0144] (3) Determination of peel strength P3 After removing the first substrate film and adhesive film from the multilayer sheet, the peel strength P3 was measured using an Autogrighur tool with test samples cut to a width of 250 mm and a length of 250 mm. During the measurement, on a flat sample stage, with one end of the test sample (where the side with the third substrate film is fixed to the top) at 0° along its length, the third substrate film was peeled 180° (towards the other end) at a peel speed of 500 mm / min, starting from one end of the test sample. The peel strength was then measured. The peel strength of five test samples was measured, and the average of the five measured strengths was taken as the peel strength P3.

[0145] 4.2 Determination of elastic modulus For the first, second, and third substrate films used in the fabrication of multilayer sheets, test pieces with a width of 25 mm × 23 cm were cut from each film. Furthermore, when determining the elastic modulus of the adhesive film, an adhesive film obtained by coating and drying on a PET film under the same conditions as in the fabrication of the multilayer sheets of each embodiment and comparative example was peeled off from the PET film, and test pieces with a width of 25 mm × 23 cm were cut from it. Next, using a Shimadzu Scientific AUTOGRAGH AGS-X (load sensor: 5 kN), according to JIS K7127 (1999), the elastic modulus of the test pieces was measured under the conditions of a measurement temperature of 23 ± 2 °C, 50 ± 5% RH, and a pulling speed of 5 mm / min.

[0146] 4.3 Evaluation of poor stripping (1) Evaluation of processability (evaluation of excessive peeling that occurs in the second zone peeling process) Using the multilayer sheets of each embodiment and comparative example, implementation Figure 1 The lamination process (first process) is shown. However, during the lamination process, the lamination section R does not perform the second process (laminated body formation process), and only the sheet body is recycled. By visually observing 100 sheet bodies obtained through 100 cycles of this test, those exhibiting excessive peeling (poor peeling where the film constituting the second region 10R2, which should not exist in the sheet body, remains) are judged as defective. Then, the percentage of good products among the 100 sheet bodies is calculated (yield rate (%)). <Note> The multilayer sheets in all embodiments and Comparative Example 1 are four-layer multilayer sheets. Here, in the context of four-layer multilayer sheets, "good quality" refers to sheets with... Figure 5 The sheet body 100A1 with the cross-sectional structure shown in (a). Furthermore, in a four-layer multilayer sheet, "defective" refers to... Figure 5 In the sheet body 100A1 shown in (a), the second region 10R2 still retains the adhesive film 14 and the second substrate film 16. In the case of the conventional three-layer multilayer sheet 10, this is equivalent to the occurrence of... Figure 16 The poor peeling condition illustrated in (a).

[0147] (2) Evaluation of peeling (evaluation of excessive peeling that occurs in the first process) Using the multilayer sheets of each embodiment and comparative example, implementation Figure 1 The lamination process (first step) is shown. However, during the lamination process, the lamination section R does not perform the second step (laminate formation process), and only the sheet body is recycled. Assuming a yield rate of 100%, the first region 10R1 in the length direction of the obtained sheet body is visually observed (equivalent to 100 parts formed by half-cutting to form the first region 10R1), thereby investigating whether excessive peeling (a peeling defect where the film constituting the first region 10R1 that should be present in the sheet body is absent) has occurred in the 100 first regions 10R1. Then, the total number of parts in the 100 first regions 10R1 that have not experienced excessive peeling (good products) is counted, and the proportion of good products (yield rate (%)) is calculated. <Note> The multilayer sheets in all embodiments and Comparative Example 1 are four-layer multilayer sheets. Here, in the context of four-layer multilayer sheets, "good quality" refers to sheets with... Figure 5 The sheet body 100A1 with the cross-sectional structure shown in (a). Furthermore, in a four-layer multilayer sheet, "defective" refers to... Figure 5In the sheet body 100A1 shown in (a), the adhesive film 14 that should be present in the first region 10R1, or the adhesive film 14 and the second substrate film 16, are absent. In the case of a conventional three-layer multilayer sheet 10, this is equivalent to the following: Figure 17 The poor peeling condition illustrated in (a).

[0148] (3) Evaluation of lamination (evaluation of delamination caused by wrinkles that occurs in the second process) Using the multilayer sheets of each embodiment, implement Figure 1 The lamination process shown is the first step. Furthermore, a glass substrate with the same shape and size as the first region 10R1 is used as the lamination target component 200. For the laminate obtained through the lamination section R (a laminate in which the third substrate film 18, the second substrate film 16, the adhesive film 14, and the lamination target component 200 are sequentially stacked), a release liner is further attached to the side of the laminate on which the lamination target component 200 is located. This release liner is then pulled downwards, causing peeling to occur at the interface with the least peel strength (the interface between the adhesive film 14 and the second substrate film 16). This performs a peeling process separating the component (sheet portion) consisting of the third substrate film 18 and the second substrate film 16, and the component consisting of the adhesive film 14 and the lamination target component 200 (laminate body portion). Then, for the 100 laminated body parts obtained after the peeling process, when visually observing the side with the adhesive film 14, the case where the surface of the adhesive film 14 is exposed is judged as "good product", and the case where the second substrate film 16 with wrinkles on the surface is further attached to the adhesive film 14 (due to peeling of the wrinkles) is judged as "defective product", and the proportion of good products (good product rate (%)) is calculated.

[0149] 4.4 Evaluation of Concealment (L value) After coating the surface of a 1 mm thick PET film with the coating liquid used in the embodiments and comparative examples for forming the adhesive film, the adhesive film was formed by drying. At this time, the thickness of the adhesive film formed on the PET film was set to be the same as the thickness of the adhesive film constituting the multilayer films of the embodiments and comparative examples. Next, the lightness L value in the Lab color system of the adhesive film formed on the surface of the PET film was measured on clean white paper. The lightness L value was measured using a spectrophotometer (NF999 SPECTROPHOTOMETER, manufactured by NIPPON DENSHOKU), in measurement mode: colorimeter, measurement conditions: C / 2°. The evaluation criteria are as follows. A: L value is below 20 B: The L value is greater than 20 and less than 50. C: L value is 50 or above Explanation of reference numerals in the attached figures

[0150] 10: Multi-layer sheet 10A, 10A1, 10A2, 10A2': Sheet body 10B, 10B1, 10B2: Do not use sheet materials. 10C: Half-cut surface 10N: Non-half-cut surface 10R1: First Zone 10R2: Second Zone 12: First substrate film 14: Adhesive film 16: Second substrate film 18: Third substrate film 20: Support roller 22: Half-cutting roller 30: Peeling claw 30S1: First support surface 30S2: Second support surface 30T: Top section 32: Support roller 40: Support roller 50: Pressure roller 52: Pressure roller 60: Peeling band 100: Multi-layer sheet 100A, 100A1, 100A2, 100A2': Sheet body 100B, 100B1, 100B2: Do not use sheet materials. 200: Laminated object component CL: Cut line HC: Half-cut section P: Peeling section R: Lamination section.

Claims

1. A multilayer sheet, wherein, The multilayer sheet comprises a first substrate film, an adhesive film, a second substrate film, and a third substrate film. The multilayer sheet is composed of the first substrate film, the adhesive film, the second substrate film and the third substrate film stacked in sequence, and satisfies the following formula (1). Equation (1) P1 <P2<P3 In the formula (1), P1 represents the peel strength (N / 250mm) between the first substrate film and the adhesive film, P2 represents the peel strength (N / 250mm) between the adhesive film and the second substrate film, and P3 represents the peel strength (N / 250mm) between the second substrate film and the third substrate film.

2. The multilayer sheet as described in claim 1, wherein, The multilayer sheet satisfies the following formula (2). Equation (2) Q2 / Q3≤2.0 In the formula (2), Q2 represents the elastic modulus (MPa) of the second substrate film, and Q3 represents the elastic modulus (MPa) of the third substrate film.

3. The multilayer sheet as described in claim 1 or 2, wherein, The peel strength P3 is 0.5N / 250mm to 15N / 250mm.

4. The multilayer sheet as described in any one of claims 1 to 3, wherein, The peel strength P2 is greater than 0.1N / 250mm and less than 5N / 250mm.

5. The multilayer sheet as described in any one of claims 1 to 4, wherein, The peel strength P1 is greater than 0.1N / 250mm and less than 5N / 250mm.

6. The multilayer sheet as described in any one of claims 1 to 5, wherein, The third substrate film is composed of a PET film and a pressure-sensitive adhesive layer disposed on one side of the PET film.

7. The multilayer sheet as described in any one of claims 1 to 6, wherein, The side of the second substrate film that is in close contact with the adhesive film is demolded.

8. The multilayer sheet as described in any one of claims 1 to 7, wherein, The adhesive film is composed of a resin composition containing epoxy resin, curing agent, inorganic filler and black pigment.

9. The multilayer sheet as described in any one of claims 1 to 8, wherein, The side of the first substrate film that is in close contact with the adhesive film is demolded.

10. The multilayer sheet as described in any one of claims 1 to 9, wherein, The multilayer sheet is used in the manufacture of semiconductor devices.

11. A method for manufacturing a laminate, wherein, The manufacturing method includes: Half-cutting process: While partially cutting the multilayer sheet of any one of claims 1 to 10 from the side of the multilayer sheet on which the first substrate film is provided, in a manner that separates the first substrate film, the adhesive film and the second substrate film, to the middle of the thickness direction of the multilayer sheet, the side of the multilayer sheet on which the first substrate film is provided is divided into a first region and a region other than the first region, i.e., a second region, by using the cutting line formed by the cutting as the boundary line; Second region peeling process: For the second region, peeling is performed at the interface between the second substrate film and the third substrate film; First step: For the first region, peeling is performed at the interface between the first substrate film and the adhesive film; and The second step involves heating and pressurizing the laminate to form a laminate, which is a laminate obtained by bonding the adhesive film of the sheet body to the surface of the laminated object component. The sheet body is one of two sheets obtained by separating the multilayer sheet into two in the thickness direction through at least the second region peeling process and the first step. The sheet body has the second substrate film and the adhesive film sequentially laminated on one side of the third substrate film and in the first region.

12. The method for manufacturing a laminate as described in claim 11, wherein, After performing the second area stripping process, the first process is performed.

13. The method for manufacturing a laminate as claimed in claim 11, wherein, The second region stripping process and the first process are basically performed simultaneously.

14. The method for manufacturing a laminate according to any one of claims 11 to 13, wherein, The multi-layer sheet is a strip sheet.

15. The method for manufacturing a laminate as described in claim 14, wherein, The first region is a plurality of circular or approximately circular regions arranged along the length of the multilayer sheet.

16. The method for manufacturing a laminate as described in claim 15, wherein, The laminated component is a semiconductor wafer or a glass wafer.

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