Composite for forming rear surface protective film, method for manufacturing third laminate, and method for manufacturing semiconductor device with rear surface protective film

Abstract

A back-surface-protection-film forming composite (1) that is formed by laminating a back-surface-protection-film forming film (13) on a protection layer (12) is used for a method for manufacturing a first laminated body, said method including: a first lamination step for bonding the back-surface-protection-film forming film (13) to a back surface of a semiconductor substrate to obtain a second laminated body in which the semiconductor substrate, the back-surface-protection-film forming film (13), and the protection layer (12) are laminated in that order; a curing step for curing the back-surface-protection-film forming film (13) of the second laminated body to obtain a back surface protection film; and a transportation step for transporting the second laminated body from the first lamination step to the curing step, whereby the first laminated body includes the semiconductor substrate, the back surface protection film, and the protection layer (12) that are laminated in that order.

Description

[Technical Field]

[0001] The present invention relates to a composite for forming a rear surface protective film, a method for manufacturing a first laminate, a method for manufacturing a third laminate, and a method for manufacturing a semiconductor device with a rear surface protective film. This application claims priority based on Japanese Patent Application No. 2020-028103, filed on February 21, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] In recent years, semiconductor devices have been manufactured using a mounting method known as the face-down method. In the face-down method, a semiconductor chip is used that has electrodes such as bumps on its circuit surface, and these electrodes are bonded to a substrate. As a result, the back surface of the semiconductor chip, opposite the circuit surface, may be exposed.

[0003] A resin film containing an organic material is formed on the back surface of the exposed semiconductor chip as a back surface protective film, and the semiconductor chip with the back surface protective film is sometimes incorporated into a semiconductor device. The back surface protective film is used to prevent cracks from occurring in the semiconductor chip after the dicing process and packaging (for example, Patent Documents 1 and 2).

[0004] Such semiconductor chips with a back surface protective film are manufactured, for example, through the steps shown in Figures 1A to 1G. That is, a method is known in which a back surface protective film-forming film 13 is laminated on the back surface 8b of a semiconductor wafer (also referred to as a "semiconductor substrate") 8 having a circuit surface (Figure 1A), the back surface protective film-forming film 13 is heat-cured or energy-ray-cured to form a back surface protective film 13' (Figure 1B), the back surface protective film 13' is laser-marked (Figure 1C), a support sheet 10 is laminated on the back surface protective film 13' (Figure 1D), the semiconductor wafer 8 and the back surface protective film 13' are diced to form semiconductor chips 7 with a back surface protective film (Figures 1E and 1F), and the semiconductor chips 7 with a back surface protective film are picked up from the support sheet 10 (Figure 1G). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent No. 4271597 [Patent Document 2] Japanese Patent No. 5363662 Summary of the Invention [Problem to be solved by the invention]

[0006] 1A is transported to a curing step in FIG. 1B in which the back surface protective film formation film 13 is thermally cured or energy ray cured to form the back surface protective film 13'. When the lamination step and the curing step are performed in separate devices, the laminate obtained in the lamination step is transported with the suction surface of the transport arm, which has suction holes, adsorbed to the back surface protective film formation film surface of the laminate, and then placed in a cassette and transported to a device that performs the curing step. In this case, there is a risk that the back surface protective film formation film may become contaminated or deformed while being transported while housed in the transport arm and cassette.

[0007] Even when the lamination process and the curing process are performed by connecting an apparatus for applying the film for forming a back surface protective film and an apparatus for curing the film for forming a back surface protective film, the laminate obtained in the apparatus for applying the film for forming a back surface protective film must be transported to the apparatus for curing the film for forming a back surface protective film, and there is a risk that the film for forming a back surface protective film may become contaminated or deformed during this process.

[0008] When the lamination step to the curing step are performed in the same device, they can be performed, for example, by a device equipped with a back surface protective film forming film attaching table, a curing unit, and a transport arm. Specifically, a work (also called a "semiconductor substrate") fed into the device is transported by the transport arm to the back surface protective film forming film attaching table, and a back surface protective film forming film, which has been processed to a size matching the work beforehand outside the device or immediately beforehand inside the device, is attached to the back side of the work to form a laminate.

[0009] The suction surface of the transport arm, which has suction holes, is attached to the surface of the film for forming a back surface protective film of the laminate, and the laminate is transported to a unit for curing. Heat is applied to the laminate transported to the unit for curing, or energy rays are irradiated, and the film for forming a back surface protective film becomes a back surface protective film.

[0010] When the inventors of the present application observed the surface of the film for forming a back surface protective film after it was transported by the transport arm, they found that deformation (unevenness) occurred due to the suction holes in the transport arm. It was also considered possible that dirt or dust might adhere to the film for forming a back surface protective film during transport, causing contamination. The occurrence of such deformation (unevenness) or adhesion of dirt or dust may result in a disadvantage of reduced reliability of the semiconductor device.

[0011] The present invention has been made in consideration of the above circumstances, and has an object to provide a composite for forming a back surface protective film, a method for manufacturing a first laminate using the composite for forming a back surface protective film, a method for manufacturing a third laminate, and a method for manufacturing a semiconductor device with a back surface protective film, which can prevent contamination and deformation of the film for forming a back surface protective film when the film for forming a back surface protective film is transported after being attached to the back surface of a semiconductor substrate in a method for manufacturing a semiconductor device with a back surface protective film. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention has the following aspects. [1] A composite for forming a back surface protective film, which is formed by laminating a protective layer and a film for forming a back surface protective film, and which is used in a method for manufacturing a first laminate in which the semiconductor substrate, the film for forming a back surface protective film, and the protective layer are laminated in this order, the method including: a first lamination step in which the film for forming a back surface protective film is attached to the back surface of a semiconductor substrate to obtain a second laminate in which the semiconductor substrate, the film for forming a back surface protective film, and the protective layer are laminated in this order; a curing step in which the film for forming a back surface protective film of the second laminate is cured to form a back surface protective film; and a transport step in which the second laminate is transported from the first lamination step to the curing step. [2] A composite for forming a back surface protective film, which is formed by laminating a protective layer and a film for forming a back surface protective film, and is used in a method for manufacturing a third laminate, the method including: a first lamination step of attaching the film for forming a back surface protective film to the back surface of a semiconductor substrate to obtain a second laminate in which the semiconductor substrate, the film for forming a back surface protective film, and the protective layer are laminated in this order; a second lamination step of attaching a support sheet to the protective layer of the second laminate to obtain a third laminate in which the semiconductor substrate, the film for forming a back surface protective film, the protective layer, and the support sheet are laminated in this order; and a transport step of transporting the second laminate from the first lamination step to the second lamination step. [3] A method for manufacturing a first laminate in which a semiconductor substrate, a back surface protective film, and a protective layer are laminated in this order, the method comprising: a first lamination step of attaching the back surface protective film formation film of the back surface protective film formation composite described in [1] to the back surface of the semiconductor substrate to obtain a second laminate in which the semiconductor substrate, the back surface protective film formation film, and the protective layer are laminated in this order; a curing step of curing the back surface protective film formation film of the second laminate to form a back surface protective film; and a transport step of transporting the second laminate from the first lamination step to the curing step. [4] A method for manufacturing a third laminate in which a semiconductor substrate, a film for forming a back surface protective film, a protective layer, and a support sheet are laminated in this order, the method comprising: a first lamination step of attaching the film for forming a back surface protective film of the composite for forming a back surface protective film described in [2] to the back surface of the semiconductor substrate to obtain a second laminate in which the semiconductor substrate, the film for forming a back surface protective film, and the protective layer are laminated in this order; a second lamination step of attaching a support sheet to the protective layer of the second laminate to obtain a third laminate in which the semiconductor substrate, the film for forming a back surface protective film, the protective layer, and the support sheet are laminated in this order; and a transport step of transporting the second laminate from the first lamination step to the second lamination step. [5] A method for manufacturing a semiconductor device with a back surface protective film, comprising: a second stacking step of attaching a support sheet to the protective layer of a first stack manufactured by the manufacturing method described in [3] to obtain a fourth stack in which the semiconductor substrate, the back surface protective film, the protective layer, and the support sheet are stacked in this order; a step of dicing the semiconductor substrate and the back surface protective film of the fourth stack to obtain a semiconductor device with a back surface protective film; and a step of picking up the semiconductor device with the back surface protective film from the support sheet. [6] A curing step of curing the film for forming a back surface protective film of the third laminate manufactured by the manufacturing method described in [4] to form a back surface protective film, thereby obtaining a fourth laminate in which the semiconductor substrate, the back surface protective film, the protective layer, and the support sheet are laminated in this order; and a step of dicing the semiconductor substrate and the back surface protective film of the fourth laminate to obtain a semiconductor device with a back surface protective film. and picking up the semiconductor device with the back surface protective film from the support sheet. [7] A step of dicing the semiconductor substrate and the film for forming a back surface protective film of the third laminate manufactured by the manufacturing method described in [4] to obtain a semiconductor device with a film for forming a back surface protective film; and a curing step of curing the film for forming a back surface protective film to form a back surface protective film. and picking up the semiconductor with the film for forming a back surface protective film or the semiconductor device with the back surface protective film from the support sheet.

[0013] [8] Use of the composite for forming a back surface protective film according to [1] or [2] for forming a back surface protective film. [9] The composite for forming a back surface protection film according to [1] or [2], wherein the film for forming a back surface protection film is formed from an uncured curable resin composition and the protective layer is formed from a cured curable resin or a thermoplastic resin; the manufacturing method according to any one of [3] to [7]; or the use according to [8]. [Effects of the Invention]

[0014] According to the present invention, in a method for manufacturing a semiconductor device with a back surface protective film, there are provided a composite for forming a back surface protective film, a method for manufacturing a first laminate using the composite for forming a back surface protective film, a method for manufacturing a third laminate, and a method for manufacturing a semiconductor device with a back surface protective film, which can prevent contamination and deformation of the film for forming a back surface protective film when the film for forming a back surface protective film is attached to the back surface of a workpiece and then transported. [Brief explanation of the drawings]

[0015] [Figure 1A] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of a conventional method for manufacturing a semiconductor chip with a back surface protective film. [Figure 1B] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of a conventional method for manufacturing a semiconductor chip with a back surface protective film. [Figure 1C] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of a conventional method for manufacturing a semiconductor chip with a back surface protective film. [Figure 1D] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of a conventional method for manufacturing a semiconductor chip with a back surface protective film. [Figure 1E] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of a conventional method for manufacturing a semiconductor chip with a back surface protective film. [Figure 1F] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of a conventional method for manufacturing a semiconductor chip with a back surface protective film. [Figure 1G] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of a conventional method for manufacturing a semiconductor chip with a back surface protective film. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of a composite for forming a rear surface protective film. [Figure 3] FIG. 2 is a schematic cross-sectional view showing an example of a composite for forming a rear surface protective film. [Figure 4A] 3A to 3C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a first laminate. [Figure 4B] 3A to 3C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a first laminate. [Figure 4C] 3A to 3C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a first laminate. [Figure 4D] 3A to 3C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a first laminate. [Figure 5A] 3A to 3C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a first laminate. [Figure 5B] 3A to 3C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a first laminate. [Figure 5C] 3A to 3C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a first laminate. [Figure 5D] 3A to 3C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a first laminate. [Figure 5E] 3A to 3C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a first laminate. [Figure 6A] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 6B] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 6C] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 6D] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 6E] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 7A] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 7B] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 7C] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 7D] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 7E] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 7F] 5A to 5C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for producing a third laminate. [Figure 8] FIG. 1 is a schematic cross-sectional view showing an example of a support sheet 10 in which a pressure-sensitive adhesive layer 102 is provided on a substrate 101. [Figure 9] FIG. 2 is a schematic cross-sectional view showing an example of a composite for forming a rear surface protective film. [Figure 10A] FIG. 10 is a schematic cross-sectional view showing a part of a process in an example of an embodiment of a method for producing a fourth laminate. [Figure 10B] FIG. 10 is a schematic cross-sectional view showing a part of a process in an example of an embodiment of a method for producing a fourth laminate. [Figure 10C] FIG. 10 is a schematic cross-sectional view showing a part of a process in an example of an embodiment of a method for producing a fourth laminate. [Figure 11A]FIG. 10 is a schematic cross-sectional view showing a part of a process in another example of an embodiment of the method for producing the fourth laminate. [Figure 11B] FIG. 10 is a schematic cross-sectional view showing a part of a process in another example of an embodiment of the method for producing the fourth laminate. [Figure 11C] FIG. 10 is a schematic cross-sectional view showing a part of a process in another example of an embodiment of the method for producing the fourth laminate. [Figure 12A] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for manufacturing a semiconductor device with a back surface protective film. [Figure 12B] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for manufacturing a semiconductor device with a back surface protective film. [Figure 12C] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for manufacturing a semiconductor device with a back surface protective film. [Figure 12D] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for manufacturing a semiconductor device with a back surface protective film. [Figure 12E] 1A to 1C are schematic cross-sectional views showing a part of a process in an example of an embodiment of a method for manufacturing a semiconductor device with a back surface protective film. [Figure 13A] 10A to 10C are schematic cross-sectional views showing a part of a process in another example of an embodiment of the method for manufacturing a semiconductor device with a back surface protective film. [Figure 13B] 10A to 10C are schematic cross-sectional views showing a part of a process in another example of an embodiment of the method for manufacturing a semiconductor device with a back surface protective film. [Figure 13C] 10A to 10C are schematic cross-sectional views showing a part of a process in another example of an embodiment of the method for manufacturing a semiconductor device with a back surface protective film. [Figure 14A] 10A to 10C are schematic cross-sectional views illustrating some steps in another example of an embodiment of the method for manufacturing a semiconductor device with a back surface protective film. [Figure 14B] 10A to 10C are schematic cross-sectional views showing a part of a process in another example of an embodiment of the method for manufacturing a semiconductor device with a back surface protective film. [Figure 14C]10A to 10C are schematic cross-sectional views showing a part of a process in another example of an embodiment of the method for manufacturing a semiconductor device with a back surface protective film. [Figure 14D] 10A to 10C are schematic cross-sectional views showing a part of a process in another example of an embodiment of the method for manufacturing a semiconductor device with a back surface protective film. DETAILED DESCRIPTION OF THE INVENTION

[0016] FIG. 2 is a cross-sectional view schematically showing one embodiment of the composite for forming a rear surface protective film of the present invention. FIG. 3 is a cross-sectional view schematically showing another embodiment of the composite for forming a back surface protection film of the present invention. In addition, the drawings used in the following explanation may show characteristic parts enlarged for convenience in order to make the features easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality.

[0017] The composite 1 for forming a rear surface protection film shown in FIG. 2 has a protective layer 12 and a film 13 for forming a rear surface protection film in this order.

[0018] The composite 1 for forming a back surface protective film of this embodiment is used in a method for producing the third laminate, which includes a first lamination step of attaching a film 13 for forming a back surface protective film to the back surface of a workpiece to obtain a second laminate in which the workpiece, the film 13 for forming a back surface protective film, and a protective layer 12 are laminated in this order, a second lamination step of attaching a support sheet to the protective layer 12 of the second laminate to obtain a third laminate in which the workpiece, the film 13 for forming a back surface protective film, the protective layer 12, and the support sheet are laminated in this order, and a transport step of transporting the second laminate from the first lamination step to the second lamination step. The composite 1 for forming a back surface protective film of this embodiment, having the protective layer 12, can prevent contamination and deformation of the film 13 for forming a back surface protective film (before curing) during the transport step.

[0019] Furthermore, the composite 1 for forming a back surface protective film of this embodiment is used in a manufacturing method of a first laminate in which the workpiece, the back surface protective film, and the protective layer 12 are laminated in this order, the method including: a first lamination step of attaching a film 13 for forming a back surface protective film to the back surface of a workpiece to obtain a second laminate in which the workpiece, the film 13 for forming a back surface protective film, and the protective layer 12 are laminated in this order; a curing step of curing the film 13 for forming a back surface protective film of the second laminate to form a back surface protective film; and a transport step of transporting the second laminate from the first lamination step to the curing step. By having the protective layer 12, the composite 1 for forming a back surface protective film of this embodiment can prevent contamination and deformation of the film 13 for forming a back surface protective film (before curing) during the transport step.

[0020] The composite 2 for forming a rear surface protection film shown in FIG. 3 includes a release film 151, a protective layer 12, and a film 13 for forming a rear surface protection film in this order.

[0021] The composite 2 for forming a back surface protective film of this embodiment is used in a method for producing the third laminate, which includes a first lamination step of attaching a film 13 for forming a back surface protective film to the back surface of a workpiece to obtain a fifth laminate in which the workpiece, the film 13 for forming a back surface protective film, a protective layer 12, and a release film 151 are laminated in this order, a second lamination step of attaching a support sheet to the protective layer 12 of the second laminate obtained by peeling the release film 151 from the fifth laminate to obtain the third laminate, and a transport step of transporting the second laminate from the first lamination step to the second lamination step. The composite 2 for forming a back surface protective film of this embodiment has the protective layer 12, which makes it possible to prevent contamination and deformation of the film 13 for forming a back surface protective film (before curing) during the transport step.

[0022] The composite 2 for forming a back surface protective film of this embodiment is used in a method for producing the first laminate, which includes a first lamination step of attaching a film 13 for forming a back surface protective film to the back surface of a workpiece to obtain a fifth laminate in which the workpiece, the film 13 for forming a back surface protective film, the protective layer 12, and a release film 151 are laminated in this order, a curing step of peeling the release film 151 from the fifth laminate to obtain a second laminate in which the film 13 for forming a back surface protective film is cured to form a back surface protective film, and a transport step of transporting the second laminate from the first lamination step to the curing step. The composite 2 for forming a back surface protective film of this embodiment has the protective layer 12, which can prevent contamination and deformation of the film 13 for forming a back surface protective film (before curing) during the transport step.

[0023] The composite 1 for forming a back surface protective film and the composite 2 for forming a back surface protective film of this embodiment are particularly preferably used in a method for manufacturing the third laminate in which at least the steps from the first lamination step to the second lamination step are performed by connecting an apparatus for attaching a film for forming a back surface protective film and an apparatus for attaching a support sheet, or by using the same apparatus.

[0024] In addition, the composite 1 for forming a back surface protective film and the composite 2 for forming a back surface protective film of this embodiment are preferably used in a method for manufacturing a first laminate in which at least the processes from the first lamination process to the curing process are carried out by connecting an apparatus for attaching a film for forming a back surface protective film and an apparatus for curing the film for forming a back surface protective film, or by using the same apparatus.

[0025] The thickness of the composite 1 for forming a back surface protective film is not particularly limited, but is preferably 30 to 550 μm, more preferably 35 to 450 μm, and even more preferably 40 to 400 μm. When the thickness of the composite 1 for forming a back surface protective film is equal to or greater than the above lower limit, the strength of the back surface protective film can be increased. When the thickness of the composite 1 for forming a back surface protective film is equal to or less than the above upper limit, the back surface protective film can be easily diced. The thickness of the composite 2 for forming a back surface protective film is not particularly limited, but is preferably 30 to 550 μm, more preferably 35 to 450 μm, and even more preferably 40 to 400 μm. When the thickness of the composite 2 for forming a back surface protective film is equal to or greater than the above lower limit, the strength of the back surface protective film can be increased. When the thickness of the composite 2 for forming a back surface protective film is equal to or less than the above upper limit, the back surface protective film can be easily diced.

[0026] Next, each layer constituting the composite for forming a rear surface protection film of this embodiment will be described.

[0027] 〇Back surface protection film formation film In the composite for forming a back surface protection film of this embodiment, the film for forming a back surface protection film is attached to a wafer (i.e., a workpiece) and cured to be used as a back surface protection film for the wafer. The film for forming a back surface protection film has curing properties and may be an energy curable film or a thermosetting film.

[0028] In this specification, "energy curable" means a property of being cured by irradiation with energy rays, and "thermosetting" means a property of being cured by application of heat.

[0029] As used herein, "energy rays" refers to electromagnetic waves or charged particle beams that have an energy quantum. Examples of energy rays include ultraviolet rays, radioactive rays, and electron beams. Ultraviolet rays can be irradiated using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet light source. Electron beams can be irradiated using those generated by an electron beam accelerator or the like.

[0030] The thickness of the film for forming a back surface protection film is not particularly limited, but is preferably 3 to 300 μm, more preferably 5 to 250 μm, and even more preferably 7 to 200 μm. When the thickness of the film for forming a back surface protection film is equal to or greater than the above lower limit, the strength of the back surface protection film can be further increased. When the thickness of the film for forming a back surface protection film is equal to or less than the above upper limit, the back surface protection film can be easily diced.

[0031] (Composition for forming backside protective film) The composition for forming a back surface protective film preferably contains a binder polymer component and a curable component. That is, the composition for forming a back surface protective film is an (uncured) curable resin composition, and the film for forming a back surface protective film is preferably formed from such a curable resin composition.

[0032] (binder polymer component) A binder polymer component is used to impart sufficient adhesiveness and film-forming properties (sheet-forming properties) to the back surface protection film-forming film. As the binder polymer component, conventionally known acrylic polymers, polyester resins, urethane resins, acrylic urethane resins, silicone resins, rubber-based polymers, etc. can be used.

[0033] The weight-average molecular weight (Mw) of the binder polymer component is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,200,000. If the weight-average molecular weight of the binder polymer component is too low, the adhesive strength between the back surface protective film-forming film and the support sheet increases, which can lead to poor transfer of the back surface protective film-forming film. If the weight-average molecular weight is too high, the adhesive strength of the back surface protective film-forming film decreases, making it impossible to transfer the film to a chip or the like, or the back surface protective film peeling off from the chip or the like after transfer. That is, when the weight-average molecular weight of the binder polymer component is equal to or greater than the above-mentioned lower limit, the adhesive strength between the back surface protective film-forming film and the support sheet increases, preventing poor transfer of the back surface protective film-forming film. When the weight-average molecular weight of the binder polymer component is equal to or less than the above-mentioned upper limit, the adhesive strength of the back surface protective film-forming film decreases, preventing it from being impossible to transfer the film to a chip or the like. In addition, when the weight-average molecular weight of the binder polymer component is equal to or less than the above-mentioned upper limit, peeling of the back surface protective film from the chip or the like after transfer can be prevented. In this specification, unless otherwise specified, the "weight average molecular weight" refers to the weight average molecular weight measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

[0034] An acrylic polymer is preferably used as the binder polymer component. The glass transition temperature (Tg) of the acrylic polymer is preferably in the range of -60 to 50°C, more preferably -50 to 40°C, and particularly preferably -40 to 30°C. If the glass transition temperature of the acrylic polymer is too low, the peel force between the back surface protective film-forming film and the support sheet increases, which can lead to poor transfer of the back surface protective film-forming film. If the glass transition temperature is too high, the adhesion of the back surface protective film-forming film decreases, making it impossible to transfer to a chip or the like, or the back surface protective film may peel off from the chip or the like after transfer. That is, when the glass transition temperature of the acrylic polymer is equal to or higher than the above-mentioned lower limit, the peel force between the back surface protective film-forming film and the support sheet increases, which can prevent poor transfer of the back surface protective film-forming film. When the glass transition temperature of the acrylic polymer is equal to or lower than the above-mentioned upper limit, the adhesiveness of the back surface protective film-forming film and the support sheet decreases, which can prevent it from being impossible to transfer to a chip or the like. In addition, when the glass transition temperature of the acrylic polymer is equal to or lower than the above-mentioned upper limit, the peeling of the back surface protective film from the chip or the like after transfer can be prevented. The glass transition temperature of the acrylic polymer can be determined, for example, by differential scanning calorimetry (DSC).

[0035] Examples of monomers constituting the acrylic polymer include (meth)acrylic acid ester monomers and derivatives thereof. Examples include alkyl (meth)acrylates in which the alkyl group has 1 to 18 carbon atoms, specifically methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Examples of (meth)acrylates having a cyclic skeleton include cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and imide (meth)acrylate. Examples of monomers having a functional group include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate, each of which has a hydroxyl group; and glycidyl (meth)acrylate, each of which has an epoxy group. The acrylic polymer is preferably an acrylic polymer containing a monomer having a hydroxyl group because it has good compatibility with the curable component described later. The acrylic polymer may also be copolymerized with acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, or the like.

[0036] In this specification, the term "(meth)acrylic acid" encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid. For example, "(meth)acrylate" encompasses both "acrylate" and "methacrylate," and "(meth)acryloyl group" encompasses both "acryloyl group" and "methacryloyl group."

[0037] Furthermore, a thermoplastic resin may be blended as a binder polymer component to maintain the flexibility of the back surface protective film after curing. Such a thermoplastic resin preferably has a weight-average molecular weight of 1,000 to 100,000, more preferably 3,000 to 80,000. The glass transition temperature of the thermoplastic resin is preferably −30 to 120°C, more preferably −20 to 120°C. Examples of the thermoplastic resin include polyester resin, thermoplastic urethane resin, phenoxy resin, polybutene, polybutadiene, and polystyrene. These thermoplastic resins can be used alone or in combination of two or more. By including the above-mentioned thermoplastic resin, the back surface protective film-forming film conforms to the transfer surface of the film, thereby suppressing the occurrence of voids and the like.

[0038] (curable component) As the curable component, one or more components selected from a thermosetting component and an energy ray curable component are used.

[0039] The thermosetting component includes a thermosetting resin and a thermosetting agent. The thermosetting resin is preferably, for example, an epoxy resin.

[0040] As the epoxy resin, conventionally known epoxy resins can be used. Specific examples of the epoxy resin include polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene epoxy resins, biphenyl epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, and phenylene skeleton epoxy resins, and other epoxy compounds having two or more functional groups in the molecule. These can be used alone or in combination of two or more.

[0041] The back surface protective film-forming film preferably contains 1 to 1,000 parts by mass, more preferably 10 to 500 parts by mass, and particularly preferably 20 to 200 parts by mass of a thermosetting resin per 100 parts by mass of the binder polymer component. If the content of the thermosetting resin is less than 1 part by mass, sufficient adhesion may not be obtained. If it exceeds 1,000 parts by mass, the peel strength between the back surface protective film-forming film and the pressure-sensitive adhesive sheet or base film may increase, resulting in poor transfer of the back surface protective film-forming film. That is, if the content of the thermosetting resin is at least the lower limit, sufficient adhesion is obtained. If the content of the thermosetting resin is less than the upper limit, the peel strength between the back surface protective film-forming film and the pressure-sensitive adhesive sheet or base film increases, preventing poor transfer of the back surface protective film-forming film.

[0042] The thermosetting agent functions as a curing agent for thermosetting resins, particularly epoxy resins. A preferred thermosetting agent is a compound having two or more functional groups per molecule that can react with epoxy groups. Examples of such functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and acid anhydrides. Of these, preferred are phenolic hydroxyl groups, amino groups, and acid anhydrides, with phenolic hydroxyl groups and amino groups being more preferred.

[0043] Specific examples of phenolic curing agents include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, Zylok-type phenolic resins, and aralkyl phenolic resins. Specific examples of amine-based curing agents include dicyandiamide (DICY). These can be used alone or in combination of two or more.

[0044] The content of the thermosetting agent is preferably 0.1 to 500 parts by mass, and more preferably 1 to 200 parts by mass, relative to 100 parts by mass of the thermosetting resin. A low content of the thermosetting agent may result in insufficient curing and insufficient adhesion, while an excessive content may increase the moisture absorption rate of the film for forming a back surface protection film, reducing the reliability of the semiconductor device. That is, when the content of the thermosetting agent is equal to or greater than the lower limit, sufficient curing is achieved and sufficient adhesion is obtained. When the content of the thermosetting agent is equal to or less than the upper limit, the increased moisture absorption rate of the film for forming a back surface protection film, which would reduce the reliability of the semiconductor device, can be prevented.

[0045] The energy ray-curable component can be a low-molecular-weight compound (energy ray-polymerizable compound) that contains an energy ray-polymerizable group and polymerizes and hardens when irradiated with energy rays such as ultraviolet rays or electron beams. Specific examples of such energy ray-curable components include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, and acrylate compounds such as 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy-modified acrylate, polyether acrylate, and itaconic acid oligomer. These compounds have at least one polymerizable double bond in the molecule and typically have a weight-average molecular weight of 100 to 30,000, preferably about 300 to 10,000. The amount of the energy ray polymerizable compound to be blended is preferably 1 to 1500 parts by mass, more preferably 10 to 500 parts by mass, and particularly preferably 20 to 200 parts by mass, per 100 parts by mass of the binder polymer component.

[0046] Alternatively, the energy ray-curable component may be an energy ray-curable polymer having an energy ray-polymerizable group bonded to the main chain or side chain of a binder polymer component. Such an energy ray-curable polymer has both the function of a binder polymer component and the function of a curable component.

[0047] The main skeleton of the energy ray-curable polymer is not particularly limited, and may be an acrylic polymer that is commonly used as a binder polymer component, or may be polyester, polyether, etc. It is particularly preferable that the energy ray-curable polymer has an acrylic polymer as the main skeleton, since this facilitates synthesis and control of physical properties.

[0048] The energy ray-polymerizable group bonded to the main chain or side chain of the energy ray-curable polymer is, for example, a group containing an energy ray-polymerizable carbon-carbon double bond, and specific examples thereof include a (meth)acryloyl group, etc. The energy ray-polymerizable group may be bonded to the energy ray-curable polymer via an alkylene group, an alkyleneoxy group, or a polyalkyleneoxy group.

[0049] The weight average molecular weight (Mw) of the energy ray curable polymer having the energy ray polymerizable group bonded thereto is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000.The glass transition temperature (Tg) of the energy ray curable polymer is preferably in the range of -60 to 50°C, more preferably -50 to 40°C, and particularly preferably -40 to 30°C.

[0050] The energy beam-curable polymer can be obtained by reacting an acrylic polymer containing a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group with a polymerizable group-containing compound that reacts with the functional group. Examples of the polymerizable group-containing compound include compounds that have one to five energy beam-polymerizable carbon-carbon double bonds and a substituent that reacts with the functional group. Examples of the substituent that reacts with the functional group include an isocyanate group, a glycidyl group, and a carboxyl group.

[0051] Examples of the polymerizable group-containing compound include (meth)acryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, (meth)acryloyl isocyanate, allyl isocyanate, glycidyl (meth)acrylate, and (meth)acrylic acid.

[0052] The acrylic polymer is preferably a copolymer consisting of a (meth)acrylic monomer having a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group, or a derivative thereof, and another (meth)acrylic acid ester monomer copolymerizable therewith, or a derivative thereof.

[0053] Examples of (meth)acrylic monomers or derivatives thereof having a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate having a hydroxyl group; acrylic acid, methacrylic acid, and itaconic acid having a carboxyl group; and glycidyl methacrylate and glycidyl acrylate having an epoxy group.

[0054] Examples of other (meth)acrylic acid ester monomers or derivatives thereof copolymerizable with the above monomers include alkyl (meth)acrylates in which the alkyl group has 1 to 18 carbon atoms, specifically methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc.; and (meth)acrylates having a cyclic skeleton, specifically cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, imide acrylate, etc. Furthermore, the above acrylic polymers may be copolymerized with vinyl acetate, acrylonitrile, styrene, etc.

[0055] Even when an energy ray-curable polymer is used, the above-described energy ray-polymerizable compound may be used in combination, or a binder polymer component may be used in combination. The relationship in the blending amounts of these three components in the film for forming a back surface protective film in this embodiment is such that the energy ray-polymerizable compound is preferably contained in an amount of 1 to 1500 parts by mass, more preferably 10 to 500 parts by mass, and particularly preferably 20 to 200 parts by mass, per 100 parts by mass of the sum of the masses of the energy ray-curable polymer and the binder polymer component. When the content of the energy ray-polymerizable compound is within the above numerical range, the curability of the composition for forming a back surface protective film can be further improved.

[0056] When a thermosetting component and an energy ray-curable component are used in combination, the mass ratio of the thermosetting component to the energy ray-curable component is, for example, preferably 5:95 to 95:5, more preferably 10:90 to 90:10, and even more preferably 15:85 to 85:15. When the mass ratio of the thermosetting component to the energy ray-curable component is within the above range, the curability of the composition for forming a back surface protective film can be further improved.

[0057] By imparting energy ray curability to the film for forming a back surface protective film, the film for forming a back surface protective film can be cured easily and in a short time, improving the production efficiency of chips with a back surface protective film. The energy ray curable film for forming a back surface protective film is cured in a short time by energy ray irradiation, allowing the back surface protective film to be formed easily and can contribute to improving production efficiency.

[0058] The film for forming a back surface protection film may contain the following components in addition to the binder polymer component and curable component.

[0059] (coloring agent) The back surface protective film preferably contains a colorant. By incorporating a colorant into the back surface protective film-forming film, infrared rays and other radiation generated by surrounding devices can be blocked when the semiconductor device is incorporated into an apparatus, thereby preventing malfunction of the semiconductor device. In addition, incorporating a colorant into the back surface protective film-forming film improves the visibility of characters when a product number or other information is printed on the back surface protective film obtained by curing the back surface protective film-forming film. In other words, in semiconductor devices or semiconductor chips having a back surface protective film formed thereon, product numbers and other information are typically printed on the surface of the back surface protective film by a laser marking method (a method in which the surface of the back surface protective film is scraped off with laser light to print). However, by incorporating a colorant into the back surface protective film, sufficient contrast is achieved between the portions of the back surface protective film scraped off with laser light and the remaining portions, improving visibility. Organic or inorganic pigments and dyes are used as colorants. Among these, black pigments are preferred in terms of their ability to block electromagnetic waves and infrared rays. Examples of black pigments that can be used include, but are not limited to, carbon black, iron oxide, manganese dioxide, aniline black, activated carbon, and the like. From the viewpoint of improving the reliability of semiconductor devices, carbon black is particularly preferred. The colorants may be used singly or in combination of two or more. The high curability of the film for forming a back surface protective film in this embodiment is particularly favorably exhibited when a colorant is used to reduce the transmittance of ultraviolet light. Examples of such colorants include colorants that reduce the transmittance of visible light, colorants that reduce the transmittance of infrared and ultraviolet light, and colorants that reduce the transmittance of visible light, infrared, and ultraviolet light. In addition to the black pigments described above, such colorants are not particularly limited as long as they have absorption or reflectivity in the wavelength region of visible light, the wavelength region of infrared and ultraviolet light, or the wavelength region of visible light, infrared, and ultraviolet light.

[0060] The blending amount of the colorant is preferably 0.1 to 35 parts by mass, more preferably 0.5 to 25 parts by mass, and particularly preferably 1 to 15 parts by mass, relative to 100 parts by mass of the total solid content constituting the film for forming a back surface protective film. When the blending amount of the colorant is equal to or greater than the above lower limit, infrared rays and the like can be sufficiently shielded. When the blending amount of the colorant is equal to or less than the above upper limit, the curability of the composition for forming a back surface protective film can be further improved.

[0061] (curing accelerator) The curing accelerator is used to adjust the curing rate of the film for forming a back surface protection film, and is preferably used particularly when an epoxy resin and a thermosetting agent are used in combination in the curable component.

[0062] Preferred curing accelerators include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. These may be used alone or in combination of two or more.

[0063] The curing accelerator is preferably contained in an amount of 0.01 to 10 parts by mass, more preferably 0.1 to 1 part by mass, per 100 parts by mass of the curable component. By including the curing accelerator in the amount within the above range, the film has excellent adhesive properties even when exposed to high temperatures and high humidity, and high reliability can be achieved even when exposed to harsh reflow conditions. If the content of the curing accelerator is too low, sufficient adhesive properties cannot be obtained due to insufficient curing. If the content of the curing accelerator is too high, the highly polar curing accelerator migrates to the adhesive interface in the film for forming a back surface protection film under high temperatures and high humidity, segregating and reducing the reliability of the semiconductor device.

[0064] (coupling agent) The coupling agent may be used to improve one or more of the adhesiveness and adhesion of the film for forming a back surface protective film to the chip and the cohesion of the back surface protective film. In addition, the use of the coupling agent can improve the water resistance of the back surface protective film obtained by curing the film for forming a back surface protective film without impairing its heat resistance.

[0065] As the coupling agent, a compound having a group that reacts with a functional group possessed by the binder polymer component, the curable component, etc. As the coupling agent, a silane coupling agent is preferred. Examples of such coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolesilane, etc. These can be used alone or in combination of two or more.

[0066] The coupling agent is typically contained in an amount of 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass, and more preferably 0.3 to 5 parts by mass, per 100 parts by mass of the binder polymer component and the curable component combined. If the content of the coupling agent is less than 0.1 part by mass, the above-mentioned effect may not be obtained, while if it exceeds 20 parts by mass, it may cause outgassing. That is, when the content of the coupling agent is equal to or greater than the above-mentioned lower limit, the above-mentioned effect is obtained. When the content of the coupling agent is equal to or less than the above-mentioned upper limit, outgassing can be suppressed.

[0067] (Inorganic filler) By incorporating an inorganic filler into the film for forming a back surface protection film, it is possible to adjust the thermal expansion coefficient of the back surface protection film after curing. Therefore, by optimizing the thermal expansion coefficient of the back surface protection film after curing relative to the semiconductor chip, the reliability of the semiconductor device can be improved. It is also possible to reduce the moisture absorption rate of the back surface protection film after curing.

[0068] Preferred inorganic fillers include powders of silica, alumina, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride, etc., spherical beads thereof, single crystal fibers, and glass fibers. Among these, silica filler and alumina filler are preferred. The inorganic fillers can be used alone or in combination of two or more. The content of the inorganic filler can be adjusted typically within the range of 1 to 80 parts by mass per 100 parts by mass of the total solid content constituting the film for forming a back surface protection film.

[0069] (Photopolymerization initiator) When the film for forming a back surface protective film contains an energy ray-curable component as the curable component, the energy ray-curable component is cured by irradiation with energy rays such as ultraviolet rays during use. In this case, by adding a photopolymerization initiator to the composition for forming a back surface protective film, the polymerization and curing time and the amount of light irradiation can be reduced.

[0070] Specific examples of such photopolymerization initiators include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, 1,2-diphenylmethane, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and β-chloroanthraquinone. The photopolymerization initiators can be used alone or in combination of two or more.

[0071] The blending ratio of the photopolymerization initiator is preferably 0.1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the energy ray-curable component. If the blending ratio is less than 0.1 part by mass, satisfactory transferability may not be achieved due to insufficient photopolymerization. If the blending ratio is more than 10 parts by mass, residues that do not contribute to photopolymerization may be generated, resulting in insufficient curing of the film for forming a back surface protective film. That is, when the blending ratio of the photopolymerization initiator is equal to or greater than the lower limit, sufficient photopolymerization occurs, resulting in satisfactory transferability. When the blending ratio of the photopolymerization initiator is equal to or less than the upper limit, the generation of residues that do not contribute to photopolymerization is suppressed, and the curing property of the film for forming a back surface protective film is further improved.

[0072] (Crosslinking agent) In order to adjust the initial adhesive strength and cohesive strength of the film for forming a back surface protection film, a crosslinking agent may be added, such as an organic polyvalent isocyanate compound or an organic polyvalent imine compound.

[0073] Examples of the organic polyisocyanate compound include aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, trimers of these organic polyisocyanate compounds, and isocyanate-terminated urethane prepolymers obtained by reacting these organic polyisocyanate compounds with polyol compounds.

[0074] Examples of organic polyisocyanate compounds include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, trimethylolpropane adduct tolylene diisocyanate, and lysine isocyanate.

[0075] Examples of the organic polyvalent imine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, and N,N'-toluene-2,4-bis(1-aziridinecarboxamide)triethylenemelamine.

[0076] The crosslinking agent is typically used in an amount of 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the total amount of the binder polymer component and the energy ray-curable polymer. When the content of the crosslinking agent is within the above range, the initial adhesive strength and cohesive strength of the film for forming a back surface protective film can be further increased.

[0077] (general-purpose additive) In addition to the above, the back surface protection film may contain various additives (general-purpose additives) as needed, such as leveling agents, plasticizers, antistatic agents, antioxidants, ion scavengers, gettering agents, and chain transfer agents.

[0078] (solvent) The composition for forming a back surface protective film preferably further contains a solvent. A composition for forming a back surface protective film containing a solvent has good handleability. The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The composition for forming a back surface protective film may contain one type of solvent or two or more types of solvents, and when two or more types of solvents are contained, the combination and ratio thereof can be selected arbitrarily. The solvent content is preferably 5 to 95 mass %, more preferably 7 to 93 mass %, and even more preferably 10 to 90 mass %, relative to the total mass of the composition for forming a back surface protective film. When the solvent content is equal to or greater than the above lower limit, the handleability of the composition for forming a back surface protective film can be further improved. When the solvent content is equal to or less than the above upper limit, the curability of the composition for forming a back surface protective film can be further improved.

[0079] The solvent contained in the composition for forming a back surface protective film is preferably methyl ethyl ketone or the like, since this allows the components contained in the composition for forming a back surface protective film to be mixed more uniformly.

[0080] The film for forming a back surface protection film obtained by applying and drying a composition for forming a back surface protection film composed of the above-mentioned components has adhesiveness and curability, and in its uncured state, it easily adheres to a workpiece (such as a semiconductor wafer or chip) when pressed against it. The film for forming a back surface protection film may be applied while being heated during pressing. After curing, a highly impact-resistant back surface protection film is finally obtained, which also has excellent adhesive strength and can maintain sufficient protective function even under harsh conditions of high temperature and high humidity. The film for forming a back surface protection film may have a single-layer structure or a multilayer structure as long as it includes one or more layers containing the above-mentioned components.

[0081] (Method of manufacturing a composition for forming a back surface protective film) The composition for forming a back surface protective film can be obtained by blending the components that constitute the composition. The order of addition of the components when blending is not particularly limited, and two or more components may be added simultaneously. When a solvent is used, the solvent may be mixed with any of the ingredients other than the solvent to pre-dilute the ingredients, or the solvent may be mixed with any of the ingredients other than the solvent without pre-diluting these ingredients. The method for mixing the components during blending is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or stirring blades, a method of mixing using a mixer, or a method of mixing by adding ultrasound. The temperature and time for adding and mixing each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. A temperature of 15 to 30°C is preferred.

[0082] (Method of manufacturing film for forming rear surface protective film) The back surface protective film-forming film can be formed using a back surface protective film-forming composition containing its constituent materials. For example, the back surface protective film-forming composition can be applied to the surface of the back surface protective film to be formed, and then dried as necessary, to form the back surface protective film-forming film in the desired location. The ratio of the contents of the components that do not vaporize at room temperature in the back surface protective film-forming composition is usually the same as the ratio of the contents of the components in the back surface protective film-forming film. In this specification, "room temperature" means a temperature that is not particularly cooled or heated, i.e., an ordinary temperature, and examples thereof include a temperature of 15 to 25°C.

[0083] The composition for forming a back surface protective film may be applied by a known method, for example, a method using various coaters such as an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater, a screen coater, a Mayer bar coater, or a kiss coater.

[0084] The drying conditions for the back surface protective film-forming composition are not particularly limited. However, when the back surface protective film-forming composition contains a solvent, as described below, it is preferably dried by heating. A solvent-containing back surface protective film-forming composition is preferably dried, for example, at 70 to 130°C for 10 seconds to 5 minutes. A solvent-containing back surface protective film-forming composition is more preferably dried at 80 to 130°C for 20 seconds to 4 minutes, and even more preferably at 90 to 130°C for 30 seconds to 3 minutes. When the heating temperature during heat drying is equal to or higher than the above lower limit, the back surface protective film-forming composition can be sufficiently cured. When the heating temperature during heat drying is equal to or lower than the above upper limit, deterioration of the workpiece can be suppressed. When the drying time during heat drying is equal to or higher than the above lower limit, the back surface protective film-forming composition can be sufficiently cured. When the drying time during heat drying is equal to or lower than the above upper limit, the productivity of the back surface protective film-forming film can be improved.

[0085] 〇Protective layer In the composite for forming a back surface protective film of this embodiment, the protective layer is used as a layer that protects the film for forming a back surface protective film. Specifically, in a method for producing a third laminate, the method includes: a first lamination step of attaching the film for forming a back surface protective film in the composite for forming a back surface protective film to the back surface of a semiconductor substrate to obtain a second laminate in which the semiconductor substrate, the film for forming a back surface protective film, and the protective layer are laminated in this order; a second lamination step of attaching a support sheet to the protective layer of the second laminate to obtain a third laminate in which the semiconductor substrate, the film for forming a back surface protective film, the protective layer, and the support sheet are laminated in this order; and a transport step of transporting the second laminate from the first lamination step to the second lamination step. In the transport step, the protective layer prevents contamination and deformation of the film for forming a back surface protective film (before curing).

[0086] In addition, the method for producing a first laminate in which the semiconductor substrate, the back surface protective film, and the protective layer are laminated in this order includes a first lamination step of attaching a film for forming a back surface protective film in a composite for forming a back surface protective film to the back surface of a semiconductor substrate to obtain a second laminate in which the semiconductor substrate, the film for forming a back surface protective film, and the protective layer are laminated in this order; a curing step of curing the film for forming a back surface protective film of the second laminate to form a back surface protective film; and a transport step of transporting the second laminate from the first lamination step to the curing step, wherein in the transport step, the protective layer prevents contamination and deformation of the film for forming a back surface protective film (before curing).

[0087] The thickness of the protective layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 2 to 95 μm, and even more preferably 3 to 90 μm. When the thickness of the protective layer is equal to or greater than the above lower limit, contamination and deformation of the film for forming a back surface protective film can be further suppressed. When the thickness of the protective layer is equal to or less than the above upper limit, the handleability of the composite for forming a back surface protective film can be further improved. The thickness of the protective layer can be determined, for example, by cutting the composite for forming a rear surface protective film in the thickness direction and observing the cross section using a microscope or the like.

[0088] The protective layer is not particularly limited, and examples thereof include an energy ray-curable film and a substrate. As the energy ray-curable film, a cured energy ray-curable film described in the film for forming a back surface protective film can be used. When an uncured energy ray-curable film is used as the protective layer, it is preferable to use a film of a different type from the film for forming a back surface protective film. Furthermore, the following energy ray-curable film for a protective layer can also be used as the protective layer. Hereinafter, an energy ray-curable film for a protective layer and a substrate for a protective layer that can be used as the protective layer will be described.

[0089] (Energy ray curable film for protective layer) The energy ray-curable film for the protective layer other than the energy ray-curable film described in the back surface protective film formation film is not particularly limited, but for example, an energy ray-curable urethane-containing resin can be used. Examples of the energy ray curable urethane-containing resin include an energy ray curable resin containing a urethane (meth)acrylate resin or a urethane polymer and an energy ray polymerizable monomer as main components. The energy ray-curable film for protective layer is preferably cured before the first lamination step of this embodiment.

[0090] (base material) The substrate that can be used as the protective layer is preferably a resin film. Examples of the resin film include polyethylene films such as low-density polyethylene (LDPE) film and linear low-density polyethylene (LLDPE) film, ethylene-propylene copolymer film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, ionomer resin film, ethylene-(meth)acrylic acid copolymer film, ethylene-(meth)acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, and fluororesin film. The substrate used in one embodiment of the present invention may be a single layer film made of one type of resin film, or may be a laminated film made of two or more types of resin films laminated together. In one embodiment of the present invention, a sheet obtained by subjecting the surface of a substrate such as the above-mentioned resin film to a surface treatment may be used as a protective layer.

[0091] These resin films may be crosslinked films. These resin films may also be colored or printed. Furthermore, the resin film may be a sheet made by extruding a thermoplastic resin, or may be a stretched film, or a sheet made by thinning and curing a curable resin by a predetermined means.

[0092] Among these resin films, a substrate having excellent heat resistance and a glass transition temperature of 70° C. or higher is preferred. Examples of films with excellent heat resistance include polyester films, polycarbonate films, polyphenylene sulfide films, cycloolefin resin films, polyimide resin films, films obtained by casting and curing ultraviolet-curable resins, and laminates of two or more of these.

[0093] When a substrate is used, the substrate alone may be used as the protective layer, or a sheet having a pressure-sensitive adhesive layer or a release agent layer on the substrate may be used as the protective layer. When a sheet having a pressure-sensitive adhesive layer or a release agent layer on the substrate is used as the protective layer, it is preferable that the pressure-sensitive adhesive layer or the release agent layer is laminated between the film for forming a back surface protection film and the substrate in the composite for forming a back surface protection film.

[0094] The pressure-sensitive adhesive layer can be appropriately selected from the pressure-sensitive adhesive layers described later in connection with the support sheet, depending on the type of substrate and film for forming a back surface protection film. The release agent layer can be appropriately selected from silicone-based, olefin-based, long-chain alkyl-based, alkyd-based, fluorine-based, and other release agent layers depending on the type of substrate and back surface protection film.

[0095] Peel-off film The release film 151 in the composite 2 for forming a back surface protection film of this embodiment is preferably a protective film. The protective film is usually composed of a base film and an adhesive layer laminated thereon. The base film can be composed of, for example, a thermoplastic resin. Examples of thermoplastic resins include polyolefin resins such as polyethylene resins and polypropylene resins; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; and (meth)acrylic resins. The adhesive layer can be composed of acrylic, rubber, urethane, or silicone resins. The release film of this embodiment is removably attached after application.

[0096] <<Method of manufacturing the third laminate>> 6A to 6E are schematic cross-sectional views showing an example of an embodiment of a method for manufacturing a third laminate using the composite for forming a back surface protective film 1. The method for manufacturing the third laminate of this embodiment is a method for manufacturing a third laminate 25 in which a workpiece 14, a film for forming a back surface protective film 13, a protective layer 12, and a support sheet 10 are laminated in this order, and includes, in this order, a first lamination step (FIGS. 6B and 6C) in which the film for forming a back surface protective film 13 of the composite for forming a back surface protective film 1 is attached to the back surface 14b of the workpiece 14 to obtain a second laminate 24 in which the workpiece 14, the film for forming a back surface protective film 13, and the protective layer 12 are laminated in this order, a transport step (FIGS. 6C to 6D) in which the second laminate 24 is transported to a second lamination step in which the support sheet 10 is attached, and a second lamination step (FIGS. 6D and 6E) in which the support sheet 10 is attached to the protective layer 12.

[0097] 7A to 7F are schematic cross-sectional views showing an example of an embodiment of a method for manufacturing a third laminate using the composite for forming a back surface protective film 2. The method for manufacturing the third laminate of this embodiment is a method for manufacturing a third laminate 25 in which a workpiece 14, a film for forming a back surface protective film 13, a protective layer 12, and a support sheet 10 are laminated in this order, and includes, in this order: a first lamination step (FIGS. 7B and 7C) in which the film for forming a back surface protective film 13 of the composite for forming a back surface protective film 2 is attached to the back surface 14b of the workpiece 14 to obtain a laminate in which the workpiece 14, the film for forming a back surface protective film 13, the protective layer 12, and a release film 151 are laminated in this order; a transport step (FIGS. 7C to 7E) in which the release film 151 is peeled from the laminate and then the laminate is transported to a second lamination step in which the support sheet 10 is attached to the protective layer 12; and a second lamination step (FIGS. 7E and 7F) in which the support sheet 10 is attached to the protective layer 12.

[0098] <<Method of manufacturing first laminate>> 4A to 4D are schematic cross-sectional views showing an example of an embodiment of a method for manufacturing a first laminate using the back surface protective film-forming composite 1. The method for manufacturing the first laminate of this embodiment is a method for manufacturing a first laminate 23 in which a workpiece 14, a back surface protective film 13′, and a protective layer 12 are laminated in this order, and includes, in this order: a first lamination step (FIGS. 4B and 4C) in which a back surface protective film-forming film 13 of the back surface protective film-forming composite 1 is attached to the back surface 14b of the workpiece 14 to obtain a second laminate 24 in which the workpiece 14, the back surface protective film-forming film 13, and the protective layer 12 are laminated in this order; a transport step (FIGS. 4C to 4D) in which the second laminate 24 is transported to a curing step in which the back surface protective film-forming film 13 is cured to form the back surface protective film 13′; and a curing step (FIG. 4D) in which the back surface protective film-forming film 13 of the second laminate 24 is cured to form the back surface protective film 13′.

[0099] 5A to 5E are schematic cross-sectional views showing an example of an embodiment of a method for producing a first laminate using the composite 2 for forming a rear surface protection film. The manufacturing method of the first laminate in this embodiment is a manufacturing method of a first laminate 23 in which a work 14, a back surface protective film 13', and a protective layer 12 are laminated in this order, and includes, in this order, a first lamination process (Figures 5B and 5C) in which a back surface protective film forming film 13 of a back surface protective film forming composite 2 is attached to the back surface 14b of the work 14 to obtain a laminate in which the work 14, the back surface protective film forming film 13, the protective layer 12, and a release film 151 are laminated in this order, a process in which the release film 151 is peeled off from the laminate to obtain a second laminate 24, a transport process (Figures 5D-E) in which the second laminate 24 is transported to a curing process in which the back surface protective film forming film 13 is cured to form the back surface protective film 13', and a curing process (Figure 5E) in which the back surface protective film forming film 13 of the second laminate 24 is cured to form the back surface protective film 13'.

[0100] Below, common features of the manufacturing method of the first laminate and the manufacturing method of the third laminate will be described. In this embodiment, a semiconductor wafer is used as the workpiece 14 shown in FIGS. 4A, 5A, 6A, and 7A. One side of the semiconductor wafer is a circuit surface on which bumps are formed. Furthermore, to prevent the circuit surface and bumps of the semiconductor wafer from being crushed during backgrinding of the semiconductor wafer or from generating dimples or cracks on the backside of the wafer, the circuit surface and bumps of the semiconductor wafer are protected by a circuit surface protection tape 17. The circuit surface protection tape 17 is a tape for backgrinding, and the backside of the semiconductor wafer serving as the workpiece 14 (i.e., the backside of the workpiece) is the ground surface. Although not shown in the manufacturing method of the first laminate shown in FIGS. 4A-D and 5A-E, it is preferable that the circuit surface and bumps of the semiconductor wafer are also protected by the circuit surface protection tape 17 in the manufacturing method of the first laminate. In this case, it is preferable to peel off the circuit surface protection tape at any stage before the curing step shown in FIG. 4D or 5E.

[0101] The workpiece 14 is not limited as long as it has a circuit surface on one side and the other side can be considered a back surface. Examples of the workpiece 14 include a semiconductor wafer having a circuit surface on one side, and a semiconductor device panel consisting of an assembly of semiconductor devices with terminals, in which individual electronic components are sealed with sealing resin and one side has a terminal formation surface (in other words, a circuit surface) of the semiconductor device with terminals.

[0102] For example, the surface protection sheets disclosed in Japanese Patent Application Laid-Open Nos. 2016-192488 and 2009-141265 can be used as the circuit surface protection tape 17. The circuit surface protection tape 17 includes an adhesive layer with suitable removability. The adhesive layer may be formed from a general-purpose weak adhesive such as a rubber-based, acrylic-based, silicone-based, urethane-based, or vinyl ether-based adhesive. The adhesive layer may also be an energy ray-curable adhesive that hardens upon irradiation with energy rays to enable removability.

[0103] In the method for producing the third laminate, the first lamination step (FIGS. 6B-C or FIG. 7B-D) and the second lamination step (FIGS. 6D-E or FIG. 7E-F) may be performed in separate devices (hereinafter also referred to as Method 1). In the method for manufacturing the third laminate, it is preferable that the steps from the first lamination step to the second lamination step (Figures 6B to E, or Figures 7B to F) are carried out by connecting an apparatus for attaching the back surface protective film forming film and an apparatus for attaching the support sheet, or by carrying out these steps in the same apparatus (hereinafter also referred to as Method 2).

[0104] In the method for producing the first laminate, the first lamination step (FIGS. 4B-C or 5B-D) and the curing step (FIG. 4D or 5E) may be performed in separate devices (hereinafter also referred to as Method 3). In the method for manufacturing the first laminate, it is preferable that the steps from the first lamination step to the curing step (Figures 4B to 4D, Figures 5B to 5E) be carried out by connecting an apparatus for attaching the film for forming a back surface protective film and an apparatus for curing the film for forming a back surface protective film, or by carrying out these steps in the same apparatus (hereinafter also referred to as Method 4).

[0105] In method 2, between the first lamination process and the second lamination process, the second laminate in which the back surface protective film forming film 13 and the protective layer 12 are laminated on the work 14 can be transported one sheet at a time to the second lamination process shown in Figures 6D to E or Figures 7E to F without being placed in a cassette. In method 4, between the first lamination process and the curing process, the second laminate in which the back surface protective film forming film 13 and the protective layer 12 are laminated on the workpiece 14 can be transported one by one to the curing process shown in Figure 4D or Figure 5E without being placed in a cassette. By performing the process in the same equipment, the equipment space can be further reduced. By connecting the equipment for attaching the back surface protective film formation film and the equipment for attaching the support sheet (or the equipment for curing the back surface protective film formation film), it is possible to modify existing equipment without having to design it from scratch, thereby reducing initial costs. Furthermore, since the second laminate is not contained in a cassette and transported outside the equipment, production efficiency is improved and contamination of the second laminate can be suppressed.

[0106] The back surface protective film forming film 13 and protective layer 12 used in the first lamination process may be processed to the shape of the work in advance, or may be processed in the same device immediately before the first lamination process is performed.

[0107] Furthermore, the back surface protective film forming film 13 and the protective layer 12 may be processed as follows after the first lamination step is performed. When the back surface protective film forming composite 1 is used, in the first lamination step, the back surface protective film forming film 13 of the back surface protective film forming composite 1 is attached to the back surface of the workpiece 14 to obtain a second laminate in which the workpiece 14, the back surface protective film forming film 13, and the protective layer 12 are laminated in this order, and then the back surface protective film forming film 13 and the protective layer 12 are processed into the shape of the workpiece.

[0108] When using the composite 2 for forming a back surface protective film, in the first lamination process, the film 13 for forming a back surface protective film of the composite 2 for forming a back surface protective film is attached to the back surface of the workpiece 14, the release film 151 is peeled off, and a laminate is obtained in which the workpiece 14, the film 13 for forming a back surface protective film, and the protective layer 12 are laminated in this order, and then the film 13 for forming a back surface protective film and the protective layer 12 are processed into the shape of the workpiece.

[0109] In another embodiment, the transport distance of the workpiece 14 from the start point of lamination in the first lamination process to the end point of lamination in the second lamination process (or from the start point of lamination in the first lamination process to the end point of curing in the curing process) can be designed to be 7000 mm or less, thereby reducing the equipment space. The transport distance of the workpiece 14 from the start point of lamination in the first lamination process to the end point of lamination in the second lamination process (or from the start point of lamination in the first lamination process to the end point of curing in the curing process) can be 6500 mm or less, 6000 mm or less, 4500 mm or less, or 3000 mm or less. The lower limit of the transport distance of the workpiece 14 is not particularly limited, but can be, for example, 100 mm.

[0110] In yet another embodiment, the transport time of the workpiece 14 from the start of attachment in the first lamination process to the completion of attachment in the second lamination process (or from the start of attachment in the first lamination process to the completion of curing in the curing process) can be set to 400 seconds or less, thereby shortening the process time. The transport time of the workpiece 14 from the start of attachment in the first lamination process to the completion of attachment in the second lamination process (or from the start of attachment in the first lamination process to the completion of curing in the curing process) can be set to 300 seconds or less, 250 seconds or less, 200 seconds or less, or 150 seconds or less. The lower limit of the transport time of the workpiece 14 is not particularly limited, but can be, for example, 10 seconds.

[0111] The speed at which the exposed surface of the back surface protective film-forming film 13 is attached to the workpiece 14 in the first lamination step in the manufacturing method of the first laminate and the manufacturing method of the third laminate, and the speed at which the support sheet 10 is attached to the exposed surface of the protective layer 12 in the second lamination step in the manufacturing method of the third laminate, can be 100 mm / sec or less, 80 mm / sec or less, 60 mm / sec or less, or 40 mm / sec or less. By setting the attaching speed in the first lamination step and the attaching speed in the second lamination step to be equal to or less than the upper limit values, the adhesion between the workpiece 14 and the back surface protective film-forming film 13 and the adhesion between the protective layer 12 and the support sheet 10 can be improved. The joining speed in the first laminating step and the joining speed in the second laminating step can be 2 mm / sec or more, 5 mm / sec or more, or 10 mm / sec or more. By making the joining speed in the first laminating step and the joining speed in the second laminating step equal to or greater than the above-mentioned lower limit value, the production efficiency of the first laminate 23 and the third laminate 25 can be improved, and the transport time of the workpiece 14 from the start of joining in the first laminating step to the completion of joining in the second laminating step (or from the start of joining in the first laminating step to the completion of curing in the curing step) can be set to 400 seconds or less.

[0112] The manufacturing method of the first laminate and the manufacturing method of the third laminate of this embodiment can be carried out by connecting an apparatus for applying a film for forming a back surface protective film and an apparatus for applying a support sheet (or an apparatus for hardening the film for forming a back surface protective film), or can be carried out within the same apparatus. The same device can be implemented, for example, by a device equipped with a back surface protective film forming film attaching table, a support sheet attaching table (or a curing unit), and a transport arm. Specifically, the workpiece placed in the device is transported by a transport arm to a back surface protective film forming film application table, and a back surface protective film forming film of the back surface protective film forming composite 1 is applied to the back surface side of the workpiece (first lamination process).

[0113] The suction surface of the transport arm, which has suction holes, is adsorbed onto the protective layer surface of the laminate obtained in the first lamination process, and the laminate is transported to the second lamination process in which a support sheet is attached (or a curing process in which the film for forming a back surface protective film is cured) (transport process).

[0114] After the above-mentioned conveying process, a support sheet is attached to the protective layer to obtain a third laminate in which the workpiece, the film for forming a back surface protective film, the protective layer, and the support sheet are laminated in this order (second lamination process). After the transporting step, the film for forming a back surface protective film is cured to obtain a first laminate in which the work, the back surface protective film, and the protective layer are laminated in this order (curing step).

[0115] By using the composite 1 for forming a back surface protection film of this embodiment, contamination and deformation of the film 13 for forming a back surface protection film can be prevented during the transport step.

[0116] The apparatus preferably includes 1 to 5 film application tables for forming a back surface protective film, and more preferably 1 to 3. When the number of film application tables for forming a back surface protective film in the apparatus is equal to or greater than the lower limit of the above range, production efficiency is improved, and when the number is equal to or less than the upper limit, the space required for the apparatus can be reduced.

[0117] The device preferably has 1 to 5 support sheet application tables, and more preferably has 1 to 3. When the number of support sheet application tables in the device is equal to or greater than the lower limit of the range, production efficiency is improved, and when the number is equal to or less than the upper limit, the space required for the device can be reduced.

[0118] The device preferably has a transport arm for each transport path. If the ratio of the number of transport arms to the total number of tables is 1 or more, production efficiency can be improved. Furthermore, when two or more tables are provided, if the ratio of the number of transport arms to the total number of tables is greater than 0 and less than 1 (for example, a total of 1 transport arm for two tables), the space required for the device can be reduced.

[0119] A specific example of connecting an apparatus for applying a film for forming a back surface protective film and an apparatus for applying a support sheet is a method in which an apparatus having a mechanism for applying a film for forming a back surface protective film and an apparatus having a mechanism for applying a support sheet are connected in series, and the second laminate in which the film for forming a back surface protective film 13 is applied to the work 14 is transported one sheet at a time using a transport arm between each mechanism. A specific example of connecting an apparatus for applying a film for forming a back surface protective film and an apparatus for hardening the film for forming a back surface protective film is a method in which an apparatus having a mechanism for applying a film for forming a back surface protective film and an apparatus having a mechanism for hardening the film for forming a back surface protective film are connected in series, and a second laminate in which a film for forming a back surface protective film 13 is applied to a work 14 is transported one sheet at a time using a transport arm between each mechanism.

[0120] In the manufacturing method of the first laminate and the manufacturing method of the third laminate of this embodiment, the first lamination step is preferably performed by the following method. Below, a case will be described in which the back surface protection film-forming film 13 and the protective layer 12 used in the first lamination step are processed into the shape of the workpiece in advance, or processed in the same device immediately before the first lamination step. A belt-shaped composite 3 for forming a back surface protection film shown in FIG. 9 having a release film 152 on the outermost surface of the film 13 for forming a back surface protection film of the composite 2 for forming a back surface protection film of this embodiment is prepared. The belt-like composite 3 for forming a back surface protection film is preferably stored in a rolled state. First, the release film 152 is peeled off, and the back surface protection film forming film 13 and the protective layer 12 are cut into the shape of the workpiece 14. Then, the laminate consisting of the back surface protection film forming film 13 and the protective layer 12 at the outer periphery is removed by rolling up.

[0121] If the protective layer 12 is not provided, the winding of the outer periphery described above involves winding only the back surface protection film forming film 13. Since the back surface protection film 13 is thin and fragile, it may be cut during winding, which may result in poor winding of the outer periphery. When the composite 3 for forming a back surface protection film of this embodiment is used, the winding of the outer periphery described above involves winding a laminate consisting of the film 13 for forming a back surface protection film and the protective layer 12. The presence of the protective layer 12 makes the laminate thicker and stronger, reducing the possibility of breakage during winding and enabling efficient winding of the outer periphery.

[0122] The composite 2 for forming a back surface protective film of this embodiment, which has been cut to the shape of the workpiece in this manner, is attached to the back surface of the workpiece 14, thereby obtaining a laminate in which the workpiece 14, the film 13 for forming a back surface protective film, the protective layer 12, and the release film 151 are laminated in this order. As described above, the release film 151 is not cut and therefore remains in a strip shape. The strip-shaped release film 151 is wound up to peel off the release film 151, thereby obtaining a second laminate 24 in which the workpiece 14, the film 13 for forming a back surface protective film, and the protective layer 12 are laminated in this order.

[0123] In the second lamination step shown in FIG. 6D or 7E in the method for producing the third laminate, a support sheet 10 is laminated on the protective layer 12. The support sheet 10 is, for example, a circular polyolefin film having a thickness of 80 μm and a diameter of 270 mm, and may have a jig adhesive layer on the outer periphery. In this embodiment, the workpiece 14 may be fixed to a fixing jig 18 together with the back surface protective film forming film 13 and the protective layer 12. Then, the support sheet 10 may be laminated on the protective layer 12 and fixed to the fixing jig 18 (FIG. 6E or 7F).

[0124] <Support sheet> Examples of the support sheet 10 used in one embodiment of the present invention include a sheet made of only a substrate 101 and an adhesive sheet having an adhesive layer 102 on a substrate 101. The support sheet of the third laminate of one embodiment of the present invention serves as a release sheet that prevents dust and the like from adhering to the surface of the film for forming a back surface protective film, or a dicing sheet that protects the surface of the film for forming a back surface protective film during a dicing process, etc.

[0125] The thickness of the support sheet is selected appropriately depending on the application, but from the viewpoint of imparting sufficient flexibility to the composite sheet and improving adhesion to the silicon wafer, it is preferably 10 to 500 μm, more preferably 20 to 350 μm, and even more preferably 30 to 200 μm. The thickness of the support sheet mentioned above includes not only the thickness of the substrate constituting the support sheet, but also the thickness of the adhesive layer or film, if any.

[0126] The substrate 101 constituting the support sheet 10 can be the same as the substrate described for the protective layer. In one embodiment of the present invention, a sheet in which the surface of a substrate such as the above-mentioned resin film has been subjected to a surface treatment may be used as the support sheet.

[0127] Among these resin films, a substrate containing a polypropylene film is preferred from the viewpoints that it has excellent heat resistance and suitable flexibility, and therefore has expandability, and also tends to maintain suitability for pickup. The base material containing a polypropylene film may have a single layer structure consisting of only a polypropylene film, or a multi-layer structure consisting of a polypropylene film and another resin film. When the film for forming a back surface protection film is thermosetting, the resin film constituting the base material has heat resistance, which can suppress damage to the base material due to heat and suppress the occurrence of defects in the manufacturing process of the semiconductor device.

[0128] When a sheet consisting of only a substrate is used as the support sheet, the surface tension of the surface of the substrate that comes into contact with the surface of the film for forming a back surface protection film is preferably 20 to 50 mN / m, more preferably 23 to 45 mN / m, and even more preferably 25 to 40 mN / m, from the viewpoint of adjusting the peel force within a certain range.

[0129] The thickness of the substrate constituting the support sheet is preferably 10 to 500 μm, more preferably 15 to 300 μm, and even more preferably 20 to 200 μm.

[0130] (adhesive sheet) An example of an adhesive sheet used as support sheet 10 in one embodiment of the present invention is one having adhesive layer 102 formed from an adhesive on substrate 101 such as the above-mentioned resin film. FIG. 8 is a schematic cross-sectional view showing an example of a support sheet 10 in which a pressure-sensitive adhesive layer 102 is provided on a substrate 101. When the support sheet 10 includes the adhesive layer 102, the adhesive layer 102 of the support sheet 10 is laminated onto the protective layer 12 in the second lamination step.

[0131] Examples of adhesives that are materials for forming the adhesive layer include adhesive compositions containing adhesive resins, and the adhesive compositions may further contain general-purpose additives such as the above-mentioned crosslinking agents and tackifiers. When attention is paid to the structure of the resin, examples of the adhesive resin include acrylic resins, urethane resins, rubber resins, silicone resins, and vinyl ether resins. When attention is paid to the function of the resin, examples of the adhesive resin include energy ray-curable adhesives, heat-foamable adhesives, and energy ray-foamable adhesives. In one embodiment of the present invention, the adhesive layer 102 of the support sheet is preferably a strong adhesive layer to ensure adhesion to the protective layer, or may be an energy ray-curable adhesive layer formed from an adhesive composition containing an energy ray-curable resin.

[0132] Moreover, from the viewpoint of adjusting the peel strength within a certain range, a pressure-sensitive adhesive containing an acrylic resin is preferred. The acrylic resin is preferably an acrylic polymer having a structural unit (x1) derived from an alkyl (meth)acrylate, and more preferably an acrylic copolymer having the structural unit (x1) and a structural unit (x2) derived from a functional group-containing monomer.

[0133] The alkyl group in the alkyl (meth)acrylate preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, and even more preferably 1 to 8 carbon atoms. Examples of the alkyl (meth)acrylate include the same alkyl (meth)acrylates as those described in the binder polymer component section above. The alkyl(meth)acrylates may be used alone or in combination of two or more kinds. The content of the structural unit (x1) is usually 50 to 100 mass%, preferably 50 to 99.9 mass%, more preferably 60 to 99 mass%, and even more preferably 70 to 95 mass%, based on all structural units (100 mass%) of the acrylic polymer.

[0134] Examples of the functional group-containing monomer include hydroxy group-containing monomers, carboxy group-containing monomers, and epoxy group-containing monomers, and specific examples of each of these monomers are the same as those exemplified in the binder polymer component section. These may be used alone or in combination of two or more. The content of the structural unit (x2) is usually 0 to 40 mass%, preferably 0.1 to 40 mass%, more preferably 1 to 30 mass%, and even more preferably 5 to 20 mass%, relative to all structural units (100 mass%) of the acrylic polymer.

[0135] The acrylic resin used in one embodiment of the present invention may also be an energy ray-curable acrylic resin obtained by reacting an acrylic copolymer having the structural units (x1) and (x2) with a compound having an energy ray-polymerizable group. The compound having an energy ray polymerizable group may be a compound having a polymerizable group such as a (meth)acryloyl group or a vinyl group.

[0136] When a pressure-sensitive adhesive containing an acrylic resin is used, it is preferable to contain a crosslinking agent together with the acrylic resin, from the viewpoint of adjusting the peel strength within a certain range. Examples of the crosslinking agent include isocyanate-based crosslinking agents, imine-based crosslinking agents, epoxy-based crosslinking agents, oxazoline-based crosslinking agents, and carbodiimide-based crosslinking agents. From the viewpoint of adjusting the peel strength within a certain range, isocyanate-based crosslinking agents are preferred. The content of the crosslinking agent is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, even more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 8 parts by mass, relative to the total mass (100 parts by mass) of the acrylic resin contained in the pressure-sensitive adhesive.

[0137] The support sheet 10 may consist of one layer (single layer) or two or more layers. When the support sheet consists of multiple layers, the constituent materials and thicknesses of these multiple layers may be the same or different, and the combination of these multiple layers is not particularly limited as long as it does not impair the effects of the present invention.

[0138] In this specification, not only in the case of support sheets, "multiple layers may be the same or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same," and further, "multiple layers are different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other."

[0139] The support sheet may be transparent or opaque, and may be colored depending on the purpose. For example, when the film for forming a back surface protection film has energy ray curability, the support sheet is preferably one that transmits energy rays. For example, in order to optically inspect the film for forming a back surface protection film through the support sheet, it is preferable that the support sheet is transparent.

[0140] In this embodiment, the circuit surface of the workpiece 14 is protected by a circuit surface protection tape 17. After the second lamination step, a peeling step can be included in which the circuit surface protection tape 17 is peeled off from the circuit surface of the workpiece 14. In this embodiment, the circuit surface protection tape 17 has an adhesive layer on the side that adheres to the circuit surface. The type of adhesive layer is not limited as long as it has appropriate removability from the workpiece. It may be formed from a general-purpose adhesive, such as a rubber-based, acrylic-based, silicone-based, urethane-based, or vinyl ether-based adhesive. It may also be formed from an energy ray-curable adhesive that hardens upon irradiation with energy rays to become removably. When the adhesive layer is formed from an energy ray-curable adhesive, the peeling step involves irradiating the adhesive layer of the circuit surface protection tape 17 with energy rays to harden the adhesive layer and make it removably, thereby easily peeling the circuit surface protection tape 17 from the circuit surface of the workpiece 14.

[0141] The method for producing the third laminate of this embodiment may include a step of laser marking by irradiating a laser onto the film 13 for forming a back surface protective film from the side of the support sheet 10. In the method for producing the third laminate of this embodiment, the support sheet 10 is laminated onto the protective layer 12, and therefore, when a laser is irradiated from the side of the support sheet 10 through the support sheet and the protective layer, laser marking can be performed on the surface of the film 13 for forming a back surface protective film that is in contact with the protective layer 12. The method for producing the first laminate of this embodiment may include a step of irradiating the film 13 for forming a back surface protection film or the back surface protection film 13' with a laser to perform laser marking.

[0142] In the methods for producing the first laminate and the third laminate, use of the composite 1 for forming a back surface protective film of this embodiment prevents contamination and deformation of the film 13 for forming a back surface protective film. Therefore, contamination and deformation of the back surface protective film 13' obtained by curing the film 13 for forming a back surface protective film are also prevented. If the film 13 for forming a back surface protective film or the back surface protective film 13' is contaminated or deformed (has an uneven surface), laser marking by irradiating a laser through the support sheet 10 will result in problems with printing and poor visibility after printing. In the manufacturing methods of the first laminate and the third laminate, by using the composite 1 for forming a back surface protective film of this embodiment, contamination and deformation of the film 13 for forming a back surface protective film (back surface protective film 13') is suppressed, and as a result, the above-mentioned printing defects are suppressed and visibility after printing is improved.

[0143] <<Method for manufacturing the fourth laminate>> The manufacturing method of the fourth laminate of this embodiment is a manufacturing method of a fourth laminate 26 in which a work 14, a back surface protective film 13', a protective layer 12, and a support sheet 10 are laminated in this order, and includes a curing step of curing the film 13 for forming a back surface protective film of the third laminate 25 manufactured by the manufacturing method of the third laminate to form a back surface protective film 13'. In addition, the manufacturing method of the fourth laminate of this embodiment is a manufacturing method of the fourth laminate 26, which includes a second lamination step in which a support sheet 10 is attached to the protective layer 12 of the first laminate 23 manufactured by the manufacturing method of the first laminate, to obtain a fourth laminate in which the workpiece 14, the back surface protective film 13', the protective layer 12, and the support sheet 10 are laminated in this order.

[0144] 10A to 10C are schematic cross-sectional views showing an example of an embodiment of a method for producing a fourth laminate. The method for producing a fourth laminate of this embodiment includes, after the second lamination step in the method for producing the third laminate, a peeling step (FIG. 10A) of peeling the circuit surface protective tape 17 from the circuit surface of the workpiece 14, a laser marking step (FIG. 10B) of irradiating the back surface protective film-forming film 13 with a laser from the support sheet 10 side to perform laser marking, and a curing step (FIG. 10C) of curing the back surface protective film-forming film 13 to form a back surface protective film 13'. In this embodiment, a thermosetting back surface protective film-forming film is used, and in the curing step of this embodiment, thermal curing is performed under conditions of 130°C and 2 hours.

[0145] The curing conditions when a thermosetting film for forming a back surface protection film is heat-treated to heat-cure it to form a back surface protection film are not particularly limited, as long as the degree of curing is such that the back surface protection film can fully perform its function, and may be selected appropriately depending on the type of thermosetting film for forming a back surface protection film.

[0146] For example, the heating temperature during thermal curing is preferably 100 to 200°C, more preferably 110 to 180°C, and particularly preferably 120 to 170°C. The heating time during thermal curing is preferably 0.5 to 5 hours, more preferably 0.5 to 3 hours, and particularly preferably 1 to 2 hours. When thermal curing is performed in the curing step, the peeling step is preferably performed before the curing step, taking into account the heat resistance of circuit surface protection tape 17.

[0147] 11A to 11C are schematic cross-sectional views showing another example of an embodiment of the method for producing the fourth laminate. The method for producing the fourth laminate of this embodiment includes, after the second lamination step in the method for producing the third laminate, a peeling step (FIG. 11A) of peeling the circuit surface protecting tape 17 from the circuit surface of the workpiece 14, a curing step (FIG. 11B) of curing the back surface protective film forming film 13 to form a back surface protective film 13', and a laser marking step (FIG. 11C) of irradiating the back surface protective film 13' with a laser from the side of the support sheet 10.

[0148] 12A and 12B are schematic cross-sectional views showing another example of an embodiment of the method for producing a fourth laminate. The method for producing a fourth laminate of this embodiment includes a second lamination step of attaching a support sheet to the first laminate 23 produced by the method for producing the first laminate. The step of peeling off the circuit surface protection tape 17 and the step of laser marking by irradiating a laser from the side of the support sheet 10 may be included in the step of producing the first laminate 23, or may be included in the step of producing a fourth laminate 26 from the first laminate 23 shown in FIGS. 12A and 12B.

[0149] <<Method for manufacturing a semiconductor device with a backside protective film>> 12C to 12E and 13A to 13C are schematic cross-sectional views showing an example of an embodiment of a method for manufacturing a semiconductor device with a back surface protective film. The method for manufacturing a semiconductor device with a back surface protective film of this embodiment includes a step of dicing the workpiece 14, the back surface protective film 13', and the protective layer 12 of the fourth stack 26 manufactured by the method for manufacturing the fourth stack to obtain a semiconductor device with a back surface protective film 22' (FIGS. 12C, 12D, 13A, and 13B), and a step of picking up the semiconductor device with a back surface protective film 22' from the protective layer 12 (FIGS. 12E and 13C).

[0150] 14A to 14D are schematic cross-sectional views showing another example of an embodiment of the method for manufacturing a semiconductor device with a back surface protective film. The method for manufacturing a semiconductor device with a back surface protective film of this embodiment includes a step of dicing the back surface protective film-forming film 13, work 14, and protective layer 12 of the third laminate 25 manufactured by the manufacturing method for the third laminate to obtain a semiconductor device with a back surface protective film-forming film 22 (FIGS. 14A and 14B), a curing step of curing the back surface protective film-forming film 13 to obtain a back surface protective film 13' (FIG. 14C), and a step of picking up the semiconductor device with a back surface protective film 22' from the support sheet 10 (protective layer 12) (FIG. 14D).

[0151] Dicing in the above-described semiconductor device manufacturing method can be performed by various dicing methods, such as blade dicing using a blade, laser dicing by irradiating a laser, or water dicing by spraying water containing an abrasive, etc. In these dicing methods, the protective layer and back surface protective film (film for forming a back surface protective film) held on the support sheet are cut together with the workpiece.

[0152] Furthermore, dicing in the semiconductor device manufacturing method described above can also be performed using Stealth Dicing (registered trademark). In Stealth Dicing (registered trademark), a planned dividing point is first set within the wafer, and a laser beam is irradiated so as to converge at this point, forming a modified layer within the wafer. Unlike other portions of the wafer, the modified layer of the wafer is altered by the irradiation of the laser beam and has reduced strength. Therefore, when force is applied to the wafer, cracks extending in the direction of both sides of the wafer occur in the modified layer within the wafer, which become the starting point for dividing (cutting) the wafer. Next, force is applied to the wafer to divide the wafer at the modified layer to produce chips. At this time, for example, a wafer with a modified layer formed thereon, which is held on a support sheet via a protective layer and a back surface protective film (a film for forming a back surface protective film), can be stretched together with the support sheet, protective layer, and back surface protective film (a film for forming a back surface protective film) in a direction parallel to the surface of the wafer, thereby applying force to the wafer to produce chips with a back surface protective film.

[0153] In the manufacturing method of the semiconductor device with a back surface protective film of this embodiment, the film 13 for forming the back surface protective film is thermosetting, and in the process of forming the back surface protective film of this embodiment, for example, the film 13 for forming the back surface protective film is thermoset under conditions of 130°C and 2 hours.

[0154] The curing conditions when a thermosetting film for forming a back surface protection film is thermally cured to form a back surface protection film are not particularly limited, as long as the degree of curing is such that the back surface protection film can fully perform its function, as described above, and may be selected appropriately depending on the type of thermosetting film for forming a back surface protection film.

[0155] In the manufacturing method of the semiconductor device with a back surface protective film of this embodiment, the film 13 for forming the back surface protective film is energy ray curable, and the process of forming the back surface protective film may be a process of irradiating the film 13 for forming the back surface protective film with energy rays to cure it with the energy rays.

[0156] The curing conditions when forming a back surface protective film by energy ray-curing an energy ray-curable film for forming a back surface protective film are not particularly limited as long as the degree of curing is such that the back surface protective film can fully exhibit its functions, and may be selected appropriately depending on the type of energy ray-curable film for forming a back surface protective film. For example, the irradiance of the energy ray during energy ray curing of the energy ray-curable back surface protection film forming film is 4 to 280 mW / cm 2 The amount of energy rays during the curing is preferably 3 to 1000 mJ / cm. 2 It is preferable that:

[0157] As the energy ray-curable film for forming a back surface protection film, for example, those disclosed in WO 2017 / 188200 and WO 2017 / 188218 can be used.

[0158] If the protective layer 12 is not provided, the semiconductor device 22' with the back surface protective film will be picked up from the support sheet 10. If a thermosetting film is used as the back surface protective film forming film 13, the adhesive strength between the cured back surface protective film 13' and the support sheet 10 will be strong, which may make picking up difficult. In this case, it is necessary to adjust the composition of the adhesive component of the support sheet, etc. On the other hand, when the composite 1 for forming a back surface protective film of this embodiment is used, the semiconductor device 22′ with the back surface protective film is picked up from the protective layer 12. In this case, if the adhesive strength between the protective layer 12 and the support sheet 10 is made sufficiently large, the pickup can be easily performed without optimizing the adhesive strength between the semiconductor device 22′ with the back surface protective film and the protective layer 12. [Example]

[0159] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the examples shown below.

[0160] <Evaluation of deformation suppression of film for forming rear surface protection film during transportation process> The wafers with the composite for forming a backside protective film obtained in Examples 1 to 3 and Comparative Example 1 described below were placed with the semiconductor wafer side facing downward on a table set at 40°C and left for 1 minute. At this time, the measured surface temperature of the table was 37 to 38°C. A standard 8" I-type robot arm (with suction holes at the tip of the arm: 34 mm diameter) equipped with suction holes was used to suction and hold the wafer with the composite for forming a backside protective film for 30 minutes under a vacuum source pressure of -80 kPa or less. The wafer with the composite for forming a backside protective film was then placed with the semiconductor wafer side facing downward on a table at room temperature, and the robot arm's suction was stopped. The top surfaces of the wafers with the composite for forming a backside protective film were visually inspected; those with no visible suction marks were rated as A, and those with visible suction marks were rated as B.

[0161] (Manufacture of back surface protection film) A first release sheet (manufactured by Lintec Corporation: SP-PET5011, thickness 50 μm) was prepared, which consisted of a polyethylene terephthalate (PET) film with a silicone-based release agent layer formed on one side, and a second release sheet (manufactured by Lintec Corporation: SP-PET381031, thickness 38 μm) was prepared, which consisted of a PET film with a silicone-based release agent layer formed on one side.

[0162] The coating solution for the back surface protective film-forming film was applied to the release surface of the first release sheet using a knife coater, and then dried in an oven at 120°C for 2 minutes to form a 40µm thick film for back surface protective film-forming. Next, the release surface of the second release sheet was placed on the film for back surface protective film-forming and the two were bonded together to obtain a sheet for back surface protective film-forming consisting of the first release sheet, the film for back surface protective film-forming (manufactured by Lintec Corporation: LC2846, thickness: 40µm), and the second release sheet.

[0163] (protective layer) The first release sheet described above, which is a sheet made of a polyethylene terephthalate (PET) film with a silicone-based release agent layer formed on one side thereof (manufactured by Lintec Corporation: SP-PET5011, thickness 50 μm), was used as protective layer 1.

[0164] A film for forming the protective layer 2 was produced by the following method. A pressure-sensitive adhesive composition with a solids concentration of 30% by mass was prepared containing an acrylic polymer (100 parts by mass, solids), a trifunctional xylylene diisocyanate crosslinker (Takenate D110N, manufactured by Mitsui Takeda Chemicals Inc.) (10.7 parts by mass, solids), and methyl ethyl ketone as a solvent. The acrylic polymer was a copolymer of 2-ethylhexyl acrylate (36 parts by mass), butyl acrylate (59 parts by mass), and 2-hydroxyethyl acrylate (5 parts by mass), and had a weight-average molecular weight of 600,000. The pressure-sensitive adhesive composition was applied to the release-treated surface of a release film (SP-PET381031, thickness 38 μm, manufactured by Lintec Corporation), one side of which had been treated for release by silicone treatment, and the composition was dried by heating at 120°C for 2 minutes to form a pressure-sensitive adhesive layer with a thickness of 5 μm. Next, a polypropylene film (Young's modulus 400 MPa, thickness 80 μm) was attached as a substrate to the exposed surface of this adhesive layer to obtain a film for forming protective layer 2 having the adhesive layer on one surface of the substrate.

[0165] As the film for forming protective layer 3, the polypropylene-based film used in the production of the film for forming protective layer 2 was used (without an adhesive layer).

[0166] [Example 1] The second release sheet on the film side for forming a back surface protective film was peeled off, and the exposed surface was attached to an 8-inch semiconductor wafer (thickness 300 μm). Furthermore, a wafer with composite A for forming a back surface protective film was obtained with the first release sheet remaining as protective layer 1. The wafer with composite A for forming a back surface protective film was evaluated for deformation of the film for forming a back surface protective film during the transport process using the method described above. The suction pressure and results in the above evaluation are shown in Table 1.

[0167] [Example 2] The second release sheet on the back surface protection film forming film side was peeled off, and the exposed surface was attached to an 8-inch semiconductor wafer (thickness 300 μm).Furthermore, the first release sheet was peeled off to expose the back surface protection film forming film, and the release film of the protective layer 2 forming film was peeled off to expose the adhesive layer, and a wafer with back surface protection film forming composite B was obtained. The wafer with backside protective film composite B was evaluated for deformation of the film for forming a backside protective film during the transport process using the method described above. The suction pressure and results in the evaluation are shown in Table 1.

[0168] [Example 3] The second release sheet on the back surface protection film forming film side was peeled off, and the exposed surface was attached to an 8-inch semiconductor wafer (thickness 300 μm).Furthermore, the first release sheet was peeled off and a film for forming protective layer 3 was attached to the exposed film for forming back surface protection film, thereby obtaining a wafer with composite C for forming back surface protection film. The wafer with backside protective film forming composite C was evaluated for deformation of the film for backside protective film formation during the transport process using the method described above. The suction pressure and results in the above evaluation are shown in Table 1.

[0169] [Comparative Example 1] The second release sheet on the back surface protection film side was peeled off, the exposed surface was attached to an 8-inch semiconductor wafer (thickness 300 μm), and then the first release sheet was peeled off to obtain a wafer with a back surface protection film. The wafers with the back surface protection film were evaluated for deformation of the film during the transport process using the method described above. The suction pressure and results of the evaluation are shown in Table 1.

[0170] [Table 1]

[0171] No adsorption marks were observed in Examples 1 to 3, which had the protective layer of the present invention, whereas adsorption marks were observed in Comparative Example 1, which did not have the protective layer of the present invention. [Industrial Applicability]

[0172] The composite for forming a back surface protective film of the present invention can be used in the production of a semiconductor device with a back surface protective film. [Explanation of symbols]

[0173] 1 Composite for forming back surface protective film, 2 Composite for forming back surface protective film, 3 Composite for molding back surface protective film, 7 Semiconductor chip with back surface protective film, 8 Semiconductor wafer, 8a Circuit side of semiconductor wafer, 8b Back side of semiconductor wafer, 9 Semiconductor chip, 10 Support sheet, 101 Base material, 102 Adhesive layer, 12 Protective layer, 13 Film for forming back surface protective film, 13' Back surface protective film , 14... work, 14a... circuit surface of work, 14b... back surface of work 14, 151... release film, 152... release film, 17... circuit surface protective tape, 18... fixing jig, 21... semiconductor device, 22... semiconductor device with back surface protective film forming film, 22'... semiconductor device with back surface protective film, 23... first laminate, 24... second laminate, 25... third laminate, 26... fourth laminate

Claims

1. A composite for forming a back surface protection film, which is formed by laminating a protective layer and a film for forming a back surface protection film, wherein the protective layer is made of an energy ray-curable film, a substrate made of a resin film alone, or the substrate on which a pressure-sensitive adhesive layer or a release agent layer is provided, The composite for forming a rear surface protective film is a first lamination step of attaching the film for forming a back surface protective film to the back surface of a semiconductor substrate to obtain a second laminate in which the semiconductor substrate, the film for forming a back surface protective film, and the protective layer are laminated in this order; a second lamination step of attaching a support sheet to the protective layer of the second laminate to obtain a third laminate in which the semiconductor substrate, the film for forming a back surface protective film, the protective layer, and the support sheet are laminated in this order; a transporting step of transporting the second laminate from the first lamination step to the second lamination step,

2. A method for producing a third laminate in which a semiconductor substrate, a film for forming a back surface protective film, a protective layer, and a support sheet are laminated in this order, wherein the protective layer is made of an energy ray-curable film, a substrate made of a resin film alone, or a substrate having a pressure-sensitive adhesive layer or a release agent layer provided thereon; The method for producing the third laminate includes: a first lamination step of attaching the film for forming a back surface protective film of the composite for forming a back surface protective film according to claim 1 to the back surface of the semiconductor substrate to obtain a second laminate in which the semiconductor substrate, the film for forming a back surface protective film, and the protective layer are laminated in this order; a second lamination step of attaching a support sheet to the protective layer of the second laminate to obtain a third laminate in which the semiconductor substrate, the film for forming a back surface protective film, the protective layer, and the support sheet are laminated in this order; and a transporting step of transporting the second laminate from the first lamination step to the second lamination step.

3. A method for manufacturing a semiconductor device with a back surface protective film, comprising: The composite for forming a back surface protective film is formed by laminating a protective layer and a film for forming a back surface protective film, and the protective layer is a substrate made of a resin film alone, or the substrate on which a pressure-sensitive adhesive layer or a release agent layer is provided, the first laminate is formed by laminating a semiconductor substrate, a back surface protective film, and the protective layer in this order; The method for producing the first laminate includes: a first lamination step of attaching the film for forming a back surface protective film of the composite for forming a back surface protective film to the back surface of the semiconductor substrate to obtain a second laminate in which the semiconductor substrate, the film for forming a back surface protective film, and the protective layer are laminated in this order; a curing step of curing the film for forming a back surface protective film of the second laminate to form a back surface protective film; a conveying step of conveying the second laminate from the first lamination step to the curing step, The method for manufacturing a semiconductor device with a back surface protective film comprises: a second lamination step of attaching a support sheet to the protective layer of the first laminate manufactured by the manufacturing method of the first laminate to obtain a fourth laminate in which the semiconductor substrate, the back surface protective film, the protective layer, and the support sheet are laminated in this order; dicing the semiconductor substrate and the back surface protective film of the fourth stack to obtain a semiconductor device with a back surface protective film; and picking up the semiconductor device with the back surface protective film from the support sheet.

4. a curing step of curing the film for forming a back surface protective film of the third laminate produced by the production method according to claim 2 to form a back surface protective film, thereby obtaining a fourth laminate in which the semiconductor substrate, the back surface protective film, the protective layer, and the support sheet are laminated in this order; dicing the semiconductor substrate and the back surface protective film of the fourth stack to obtain a semiconductor device with a back surface protective film; and picking up the semiconductor device with the back surface protective film from the support sheet.

5. a step of dicing the semiconductor substrate and the film for forming a back surface protective film of the third laminate manufactured by the manufacturing method according to claim 2 to obtain a semiconductor device with a film for forming a back surface protective film; a curing step of curing the film for forming a back surface protective film to form a back surface protective film; and picking up the semiconductor with the film for forming a back surface protective film or the semiconductor device with the back surface protective film from the support sheet.

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