Method for manufacturing workpiece with protective film and method for manufacturing workpiece with film forming protective film

Abstract

Provided is a method for manufacturing a workpiece with a protective film, in which a fourth laminate in which a workpiece (14), a protective film (13'), and a support sheet (10) are sequentially stacked is formed, and the protective film (13') of the fourth laminate is subjected to laser irradiation from the support sheet (10) side, whereby a surface of the protective film (13') on the support sheet (10) side is laser-marked while a gas pocket (30) is formed between the protective film (13') and the support sheet (10).

Description

Technical Field

[0001] This invention relates to a method for manufacturing a workpiece with a protective film and a method for manufacturing a workpiece with a protective film forming film. More specifically, it relates to a method for manufacturing a workpiece with a protective film, comprising a workpiece such as a semiconductor wafer, a protective film protecting the workpiece, and a support sheet, wherein the surface of the protective film on the support sheet side is laser-marked; and a method for manufacturing a workpiece with a protective film forming film, comprising a workpiece, a protective film forming film, and a support sheet, wherein the surface of the protective film forming film on the support sheet side is laser-marked.

[0002] This application claims priority based on Japanese Patent Application No. 2020-205010 filed in Japan on December 10, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] In recent years, semiconductor devices using a mounting method known as flip-chip have been manufactured. In flip-chip technology, a semiconductor chip with electrodes such as bumps on its circuit surface is used, and these electrodes are bonded to a substrate. Therefore, the back side of the semiconductor chip, opposite to the circuit surface, is sometimes exposed.

[0004] Sometimes a resin film containing organic material is formed as a protective film on the back side of the exposed semiconductor chip, and the semiconductor chip is mounted in the semiconductor device as a semiconductor chip with a protective film. The protective film is used to prevent cracks from forming on the semiconductor chip after the dicing process or packaging (e.g., Patent Documents 1-5).

[0005] Such semiconductor chips with protective films can, for example, undergo... Figure 12 The process shown is used for manufacturing. Specifically, a known method involves stacking a protective film forming composite sheet 1 (where a protective film forming film 13 and a support sheet 10 are integrally formed) on the back side 8b of a semiconductor wafer 8 having a circuit surface. Figure 12 (A) of the circuit, peel off the protective tape 17 (as needed). Figure 12 (B) of the process involves heat curing or energy radiation curing of the protective film 13 to form a protective film 13'. Figure 12 In (C)), laser marking is performed on the surface of the support sheet 10 side of the protective film 13'. Figure 12 (D)), cutting semiconductor wafer 8 and protective film 13' ( Figure 12 (E)) Pick up the semiconductor chip 7 with protective film from the support sheet 10. Figure 12 (F) in the middle.

[0006] Among them, for in Figure 12 The apparatus for laser marking in (D) and in Figure 12The apparatus for dicing the semiconductor wafer 8 and the protective film 13' in (E) uses different devices. For example, in Figure 12 The fourth stack 19' (a stack of workpieces such as semiconductor wafer 8, protective film 13' and support sheet 10) after laser marking in (D) is stored in a frame cassette or frame box (film frame shipper) with a ring frame or other fixing clamp 18. In most cases, it is manually transported to the outside of the laser marking device.

[0007] In addition, it is known that there are such Figure 13 The method shown is as follows: a protective film forming composite sheet 1, which integrates a protective film forming film 13 and a support sheet 10, is laminated on the back side 8b of a semiconductor wafer 8 having a circuit surface. Figure 13 (A) of the circuit, peel off the protective tape 17 (as needed). Figure 13 In (B) of the diagram, laser marking is performed on the surface of the support sheet 10 side of the protective film forming film 13. Figure 13 The protective film 13' is formed by heat curing or energy radiation curing of the protective film 13 (D')). Figure 13 (C')), cutting semiconductor wafer 8 and protective film 13' ( Figure 13 (E)) Pick up the semiconductor chip 7 with protective film from the support sheet 10. Figure 13 (F) in the middle.

[0008] Among them, for in Figure 13 The device for laser marking in (D') Figure 13 The apparatus for heat curing or energy radiation curing in (C') and in Figure 13 The apparatus for dicing the semiconductor wafer 8 and the protective film 13' in (E) also uses different apparatus. For example, in Figure 13 The third laminate 19 (a laminate of workpieces such as semiconductor wafer 8, protective film forming film 13, and support sheet 10) after laser marking in (D') is stored in a frame box or frame case (film frame case) with a fixing clamp 18 such as an annular frame, and is usually manually transported outside the laser marking device. The fourth laminate 19' is also stored in a frame box or frame case (film frame case), and is usually manually transported outside the device for thermosetting or energy ray curing.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: International Publication No. 2014 / 157426

[0012] Patent Document 2: International Publication No. 2013 / 047674

[0013] Patent Document 3: Japanese Patent Application Publication No. 2016-225496

[0014] Patent Document 4: International Publication No. 2016 / 195071

[0015] Patent Document 5: International Publication No. 2018 / 179475 Summary of the Invention

[0016] The technical problem to be solved by the present invention

[0017] exist Figure 12 , Figure 13 In the conventional semiconductor chip manufacturing method with a protective film shown, when operating on the third laminate 19 (a laminate of a workpiece such as a semiconductor wafer, a protective film forming film capable of forming a protective film to protect the back of the workpiece and simultaneously improve its appearance and a support sheet) or the fourth laminate 19' (a laminate of a workpiece, a protective film and a support sheet) after laser marking outside the laser marking apparatus, there is a possibility that the laser markings on the protective film forming film or the protective film can be easily read through the support sheet, thereby leaking text information.

[0018] The present invention was made in view of the above circumstances, and its technical problem is to provide a method for manufacturing a workpiece with a protective film forming film that can shield the laser marking on the protective film forming film or the protective film when operating on a workpiece with a protective film forming film after laser marking or a workpiece with a protective film forming film after laser marking.

[0019] Technical means to solve technical problems

[0020] The present invention provides a method for manufacturing a workpiece with a protective film.

[0021] [1] A method for manufacturing a workpiece with a protective film, wherein,

[0022] This forms a fourth layer consisting of a workpiece, a protective film, and a support sheet stacked sequentially.

[0023] Laser irradiation is performed on the protective film of the fourth laminate from the support sheet side, thereby creating gas retention between the protective film and the support sheet while laser marking is performed on the surface of the protective film on the support sheet side.

[0024] [2] According to the manufacturing method of the workpiece with protective film described in [1], wherein,

[0025] A composite sheet for forming a protective film, comprising a protective film forming film and a support sheet, is formed.

[0026] A workpiece is attached to the protective film forming film of the composite sheet for forming the protective film, thereby forming a third laminate in which the workpiece, the protective film forming film, and the support sheet are sequentially stacked.

[0027] The protective film of the third laminate is cured to form the fourth laminate.

[0028] [3] According to the manufacturing method of the workpiece with protective film described in [1], wherein,

[0029] A first laminate is formed, consisting of a workpiece and a protective film.

[0030] The protective film of the first laminate is cured to form a second laminate containing the workpiece and the protective film.

[0031] A support sheet is attached to the protective film of the second laminate to form the fourth laminate.

[0032] [4] According to the manufacturing method of the workpiece with protective film described in [1], wherein,

[0033] A first laminate is formed, consisting of a workpiece and a protective film.

[0034] A support sheet is attached to the protective film forming film of the first laminate to form a third laminate in which the workpiece, the protective film forming film, and the support sheet are sequentially stacked.

[0035] The protective film of the third laminate is cured to form the fourth laminate.

[0036] [5] A method for manufacturing a workpiece with a protective film according to any one of [1] to [4], wherein,

[0037] The support sheet has an adhesive layer stacked on the substrate, and the fourth stack consists of the workpiece, the protective film, the adhesive layer, and the substrate stacked in sequence.

[0038] [6] A method for manufacturing a workpiece with a protective film forming a film, wherein,

[0039] A third laminate is formed, consisting of a workpiece, a protective film forming film, and a support sheet stacked sequentially.

[0040] Laser irradiation is performed on the protective film forming film of the third laminate from the support sheet side, thereby creating gas retention between the protective film forming film and the support sheet, and simultaneously laser marking is performed on the surface of the protective film forming film on the support sheet side.

[0041] [7] The manufacturing method of the workpiece with a protective film forming film according to [6], wherein,

[0042] A composite sheet for forming a protective film, comprising a protective film forming film and a support sheet, is formed.

[0043] The workpiece is attached to the protective film forming film of the composite sheet for forming the protective film to form the third laminate.

[0044] [8] The manufacturing method of the workpiece with a protective film forming film according to [6], wherein,

[0045] A first laminate is formed, consisting of a workpiece and a protective film.

[0046] A support sheet is attached to the protective film forming film of the first laminate to form a third laminate in which the workpiece, the protective film forming film and the support sheet are stacked in sequence.

[0047] [9] A method for manufacturing a workpiece with a protective film formed according to any one of [6] to [8], wherein,

[0048] The support sheet has an adhesive layer stacked on the substrate, and the third stack consists of the workpiece, the protective film forming film, the adhesive layer, and the substrate stacked sequentially.

[0049]

[10] A method for manufacturing a workpiece with a protective film, wherein the protective film formed by laser marking of the workpiece with a protective film formed by any one of the methods described in [6] to [9] is subjected to a curing treatment.

[0050]

[11] A method for manufacturing a workpiece with a protective film, wherein the workpiece with a protective film obtained by any one of the methods described in [1] to [5] is subjected to pressure treatment or heat treatment to make the gas retention disappear.

[0051]

[12] A method for manufacturing a workpiece with a protective film forming film, wherein the workpiece with a protective film forming film obtained by any one of the methods described in [6] to [9] is subjected to pressure treatment or heat treatment to make the gas retention disappear.

[0052]

[13] A method for manufacturing a workpiece with a protective film, wherein the workpiece with a protective film obtained by the method described in

[10] is subjected to pressure treatment or heat treatment to make the gas retention disappear.

[0053] Invention Effects

[0054] According to the present invention, a method for manufacturing a workpiece with a protective film forming film and a method for manufacturing a workpiece with a protective film can be provided. When the method operates on a workpiece with a protective film forming film after laser marking or a workpiece with a protective film after laser marking, it can shield the laser marking on the protective film forming film or the protective film. Attached Figure Description

[0055] Figure 1A A cross-sectional schematic diagram illustrating a portion of the steps in an example of a method for manufacturing a workpiece with a protective film.

[0056] Figure 1B A cross-sectional schematic diagram illustrating a portion of the steps in an example of an embodiment of a method for manufacturing a workpiece with a protective film.

[0057] Figure 1C A cross-sectional schematic diagram illustrating a portion of the steps in an example of an embodiment of a method for manufacturing a workpiece with a protective film.

[0058] Figure 1D A cross-sectional schematic diagram illustrating a portion of the steps in an example of a method for manufacturing a workpiece with a protective film.

[0059] Figure 1E A cross-sectional schematic diagram illustrating a portion of the steps in an example of an embodiment of a method for manufacturing a workpiece with a protective film.

[0060] Figure 1F A cross-sectional schematic diagram illustrating a portion of the steps in an example of an embodiment of a method for manufacturing a workpiece with a protective film.

[0061] Figure 1G A cross-sectional schematic diagram illustrating a portion of the steps in an example of an embodiment of a method for manufacturing a workpiece with a protective film.

[0062] Figure 2 A top view illustrating an example of a third laminate 19 in which a workpiece 14 is attached to a protective film forming film 13 of a composite sheet for forming a protective film.

[0063] Figure 3 A cross-sectional schematic diagram is shown to illustrate an example of sheet 4 for forming a protective film.

[0064] Figure 4 A cross-sectional schematic diagram is shown to illustrate an example of the support piece 10.

[0065] Figure 5 This is a cross-sectional schematic diagram illustrating an example of a process involving pressure treatment or heat treatment of a workpiece with a protective film after laser marking.

[0066] Figure 6 A cross-sectional schematic diagram illustrating an example of a workpiece with a protective film that eliminates gas retention.

[0067] Figure 7A This is a cross-sectional schematic diagram illustrating a portion of the steps in an example of a method for manufacturing a workpiece with a protective film forming.

[0068] Figure 7B This is a cross-sectional schematic diagram illustrating a portion of the steps in an example of a method for manufacturing a workpiece with a protective film forming.

[0069] Figure 7C This is a cross-sectional schematic diagram illustrating a portion of the steps in an example of an embodiment of a method for manufacturing a workpiece with a protective film forming a film.

[0070] Figure 7D This is a cross-sectional schematic diagram illustrating a portion of the steps in an example of a method for manufacturing a workpiece with a protective film forming.

[0071] Figure 7E This is a cross-sectional schematic diagram illustrating a portion of the steps in an example of an embodiment of a method for manufacturing a workpiece with a protective film forming a film.

[0072] Figure 8 This is a cross-sectional schematic diagram illustrating an example of a process involving pressure treatment or heat treatment of a workpiece with a protective film formed after laser marking.

[0073] Figure 9 A cross-sectional schematic diagram illustrating an example of a workpiece with a protective film formed after the gas retention has disappeared.

[0074] Figure 10A A cross-sectional schematic diagram illustrating a portion of the steps in another example of a method for manufacturing a workpiece with a protective film.

[0075] Figure 10B A cross-sectional schematic diagram illustrating a portion of the steps in another example of a method for manufacturing a workpiece with a protective film.

[0076] Figure 11 A cross-sectional schematic diagram is provided to illustrate another example of a method for manufacturing a workpiece with a protective film forming a film (i.e., a partial step in another example of a method for manufacturing a workpiece with a protective film).

[0077] Figure 12 A cross-sectional schematic diagram illustrating an example of a method for manufacturing a semiconductor chip with a protective film.

[0078] Figure 13 A cross-sectional schematic diagram illustrating another example of a method for manufacturing a semiconductor chip with a protective film.

[0079] Explanation of reference numerals in the attached figures

[0080] 1: Composite sheet for forming protective film; 4: Sheet for forming protective film; 5: First laminate; 6: Second laminate; 7: Semiconductor chip with protective film; 8: Semiconductor wafer; 8b: Back side of semiconductor wafer; 9: Semiconductor chip; 10: Support sheet; 11: Substrate; 12: Adhesive layer; 13: Protective film forming film; 13': Protective film; 13a: First side of protective film forming film; 13b: Second side of protective film forming film; 14: Workpiece; 14a: Circuit surface of workpiece; 14b: Back side of workpiece; 151: First release film; 152: Second release film; 16: Adhesive layer for clamping; 17: Tape for protecting circuit surface; 18: Fixing clamp; 19: Third laminate; 19': Fourth laminate; 30: Gas retention. Detailed Implementation

[0081] <<Manufacturing Method of Workpieces with Protective Film>>

[0082] In the manufacturing method of the workpiece with protective film of the present invention, a fourth laminate consisting of a workpiece, a protective film and a support sheet are formed in sequence. The protective film of the fourth laminate is irradiated with a laser from the support sheet side, thereby creating gas retention between the protective film and the support sheet and laser marking the surface of the protective film on the support sheet side.

[0083] The manufacturing method of the workpiece with a protective film of the present invention involves laser irradiating the protective film of the fourth laminate from the support sheet side, forming a gas entrapment between the protective film and the support sheet, and simultaneously laser marking the surface of the protective film on the support sheet side. Therefore, when operating the workpiece with the protective film after laser marking, the laser marking on the protective film can be shielded, and the information leakage of the laser marking can be prevented even by manual operation.

[0084] <Manufacturing method of workpiece with protective film according to the first embodiment>

[0085] In the manufacturing method of a workpiece with a protective film according to the first embodiment of the present invention, a composite sheet for forming a protective film is formed, which has a protective film forming film and a support sheet stacked on top of each other.

[0086] A workpiece is attached to the protective film forming film of the composite sheet for forming the protective film, thereby forming a third laminate in which the workpiece, the protective film forming film, and the support sheet are sequentially stacked.

[0087] The protective film of the third laminate is cured to form the fourth laminate. The protective film of the fourth laminate is irradiated with a laser from the support sheet side, thereby creating gas retention between the protective film and the support sheet while laser marking is performed on the surface of the protective film on the support sheet side.

[0088] Hereinafter, the manufacturing method of a workpiece with a protective film according to the first embodiment of the present invention will be described in detail with reference to the accompanying drawings. Figures 1A to 1G This is a cross-sectional schematic diagram illustrating an example of a method for manufacturing a workpiece with a protective film according to this embodiment. Furthermore, for the accompanying drawings used in the following description, for ease of understanding, feature portions may sometimes be shown enlarged, and the dimensional ratios of the constituent elements may not be the same as in reality.

[0089] For example, a protective film forming film 13 is laminated onto the adhesive layer 12 of a support sheet 10, which is formed by laminating an adhesive layer 12 onto a substrate 11 made of a circular polypropylene film with a thickness of 80 μm. Then, an annular clamping adhesive layer 16 is laminated onto the periphery of the protective film forming film 13 on the side opposite to the support sheet 10 to form a composite sheet 1 for forming a protective film. Figure 1A The details of the protective film forming process and the support sheet manufacturing process will be described later.

[0090] On the protective film forming film 13 of the composite sheet 1 for forming a protective film, a back side of a workpiece 14, such as a semiconductor wafer, opposite to the circuit surface, is attached, forming a third laminate 19 in which the workpiece 14, the protective film forming film 13, and the support sheet 10 are sequentially stacked. Figure 1B ). Figure 2 This is a top view of the third laminate 19 in which the workpiece 14 is attached to the composite sheet 1 for forming the protective film.

[0091] In this embodiment, the workpiece 14 may be exemplified as a semiconductor device panel consisting of a semiconductor device assembly having a terminal forming surface (in other words, a circuit surface) on one side, which is sealed with a sealing resin for each individual electronic component that has been singulated, or a semiconductor wafer having a circuit surface on one side.

[0092] In this specification, the “back side” of a workpiece refers to the side opposite the circuit surface of the workpiece.

[0093] In this embodiment, a semiconductor wafer is used as workpiece 14. One side of the semiconductor wafer is a circuit surface 14a, which may have bumps formed on it. Furthermore, to prevent the circuit surface 14a and bumps of the semiconductor wafer from being crushed or developing dimples or cracks on the back side of the wafer during grinding, circuit surface protective tape is used to protect the circuit surface 14a and bumps of the semiconductor wafer. The circuit surface protective tape is a back-grinding tape, and the back side of the semiconductor wafer opposite to the circuit surface (i.e., the back side of the workpiece) is ground.

[0094] An adhesive layer 16 for attaching the third laminate 19 to the fixing clamp 18 (e.g., annular frame). Figure 1C If necessary, peel off the protective tape from the circuit surface before curing the protective film forming film 13.

[0095] The protective film 13 of the third laminate 19 is cured. Figure 1D This forms a fourth laminate 19' consisting of the workpiece 14, the protective film 13', and the support sheet 10 stacked sequentially. Figure 1E Through a curing process, the protective film forming film 13 is transformed into a protective film 13'. The protective film forming film 13 can be thermosetting or energy-curable. If the protective film forming film 13 is thermosetting, the curing process is a thermosetting process; if the protective film forming film 13 is energy-curable, the curing process is an energy-curable process.

[0096] As long as the degree of curing of the protective film is sufficient to fully realize its function, there are no particular limitations on the curing conditions for the thermosetting protective film to be formed by heat curing. The appropriate conditions can be selected according to the type of thermosetting protective film.

[0097] For example, the heating temperature for thermosetting protective film formation during film curing is preferably 100–200°C, more preferably 110–170°C, and particularly preferably 120–150°C. Furthermore, the heating time for thermosetting is preferably 0.5–5 hours, more preferably 0.5–4 hours, and particularly preferably 1–3 hours.

[0098] As long as the degree of curing is sufficient to allow the protective film to fully perform its function, there are no particular limitations on the curing conditions when energy-curable protective films are formed by energy-curing. Appropriate conditions can be selected based on the type of energy-curable protective film.

[0099] For example, the irradiance of the energy rays used in the energy ray curing of the protective film is preferably 4–280 mW / cm². 2Furthermore, the intensity of the energy rays during curing is preferably 3–1000 mJ / cm². 2 .

[0100] In this specification, "energy rays" refers to rays containing energy quanta within electromagnetic waves or beams of charged particles. Examples of energy rays include ultraviolet light, radiation, and electron beams. Ultraviolet light can be obtained by irradiation using high-pressure mercury lamps, fusion lamps, xenon lamps, black lights, or LED lights as ultraviolet light sources. Electron beams can be obtained by irradiation using electron beam accelerators or similar devices.

[0101] Furthermore, in this specification, "energy-curable" refers to the property that is cured by irradiation with energy rays, and "non-energy-curable" refers to the property that is not cured even when irradiated with energy rays.

[0102] The fourth laminate 19' consists of the workpiece 14, the protective film 13', the adhesive layer 12, and the substrate 11, which are stacked sequentially. Figure 1E ).

[0103] By laser irradiating the protective film 13' of the fourth laminate 19' from the support sheet 10 side, a gas retention 30 can be formed between the protective film 13' and the support sheet 10, while simultaneously laser marking can be performed on the surface of the protective film 13' on the support sheet 10 side. Figure 1F This enables the manufacture of workpiece 14 with a protective film 13' after laser marking. Figure 1G ).

[0104] Previously, the output power for laser marking on the protective film 13' was affected by factors such as the size of the text or the materials contained in the protective film, and was, for example, 0.1 to 0.3 W. In order to form a gas retention 30 between the protective film 13' and the support sheet 10 to properly shield the laser marking on the protective film 13', the output power for laser marking is preferably 0.40 W or more, more preferably 0.45 W or more, and even more preferably 0.48 W or more.

[0105] When comparing the situation where gas retention occurs due to laser marking on the protective film forming film, and the situation where gas retention occurs due to laser marking on a protective film forming film with the same formulation as the aforementioned protective film forming film, the output power of laser marking is suppressed less when the protective film is laser marked. This is believed to be because when laser marking is performed on the protective film forming film, the generated gas easily diffuses and is absorbed into the protective film forming film, while the degree of gas diffusion and absorption is suppressed to a lower extent when laser marking is performed on the protective film forming film.

[0106] In the manufacturing method of the workpiece with a protective film according to the first embodiment, a gas trap 30 is formed between the adhesive layer 12 of the support sheet 10 and the protective film 13'. Therefore, when operating on the workpiece with the protective film after laser marking, the laser marking on the protective film 13' can be appropriately shielded, and the leakage of information from the laser marking can be prevented even by manual operation.

[0107] For gas retention formed in workpieces with protective films, the number of characters in the text of the evaluation object that come into contact with the gas retention can be counted and evaluated using the gas retention rate defined by the following formula.

[0108] Gas retention rate (%) = (Number of characters contacted by gas retention / Total number of characters) × 100

[0109] The gas retention rate formed in the workpiece with the protective film is preferably 10% or more, more preferably 20% or more, even more preferably 35% or more, even more preferably 60% or more, and particularly preferably 80% or more.

[0110] (Method for manufacturing protective film forming film and sheet for protective film forming)

[0111] The protective film forming film 13 and the protective film forming sheet 4 can be manufactured, for example, by coating a protective film forming composition containing a solvent onto the release surface of the second release film 152 with a thickness of 38 μm using a doctor blade coater, and then drying it in an oven at 120°C for 2 minutes to form the protective film forming film. Then, the release surface of the first release film 151 with a thickness of 38 μm is overlapped onto the protective film forming film, and the two are bonded together to obtain a structure consisting of the first release film 151, the protective film forming film 13, and the second release film 152. Figure 3 Protective film forming sheet 4. Such protective film forming sheet 4 is suitable for, for example, being rolled up for storage.

[0112] (Protective film forming composition)

[0113] As a component of a protective film forming composition used to manufacture protective film forming films and protective film forming sheets, a protective film forming composition without curing components can be used in applications where strong protective performance is not required. This is easy to use as it eliminates the need for a curing process. However, it may not achieve sufficient adhesion and protective performance to brittle chips. Preferably, the protective film forming composition used to form the protective film forming film contains both polymeric and curing components.

[0114] In this specification, a protective film formed from a protective film forming composition that does not contain curable components is considered a protective film at the moment when the workpiece with the protective film forming film is peeled off from the support sheet.

[0115] Polymer components are sometimes also considered curable components. In this specification, when a protective film forming composition contains components that are both polymeric and curable, it is considered that the protective film forming composition contains both polymeric and curable components.

[0116] (Polymer composition)

[0117] To impart sufficient adhesion and film-forming properties (sheet-forming properties) to the protective film, a polymer component can be used. Suitable polymer components include acrylic resins, urethane resins, phenoxy resins, silicone resins, and saturated polyester resins. Acrylic resins are preferred as the polymer component.

[0118] The weight-average molecular weight (Mw) of the polymer component is preferably between 10,000 and 2,000,000, more preferably between 100,000 and 1,200,000. If the weight-average molecular weight of the polymer component is above the lower limit mentioned above, it tends to have a lower adhesion to the support sheet 10, and gas trapping is more likely to occur. If the weight-average molecular weight of the polymer component is below the upper limit mentioned above, the gas trapping is more likely to disappear when the gas trapping is eliminated by pressurization or heating.

[0119] The glass transition temperature (Tg) of the polymer component is preferably in the range of -60 to 50°C, more preferably in the range of -50 to 40°C, and particularly preferably in the range of -40 to 30°C.

[0120] If the glass transition temperature of the polymer component is above the lower limit mentioned above, gas trapping is likely to occur. If the glass transition temperature of the polymer component is below the upper limit mentioned above, the gas trapping is easily eliminated when it is eliminated by pressure treatment or heat treatment, and the risk of cracking (fracture) when the protective film is bent during rolling is reduced.

[0121] From the perspective of adhesion, bonding and film-forming properties, the preferred content of polymer components relative to a protective film forming film with a total weight of 100 (parts by mass) is 5-50 parts by mass, 10-45 parts by mass, 14-40 parts by mass, and 18-35 parts by mass.

[0122] The glass transition temperature (Tg) of the resin that constitutes the polymer component can be calculated using the Fox formula shown below.

[0123] 1 / Tg=(W1 / Tg1)+(W2 / Tg2)+…+(Wm / Tgm)

[0124] In the formula, Tg is the glass transition temperature of the resin constituting the polymer component, Tg1, Tg2, ..., Tgm are the glass transition temperatures of the homopolymers of each monomer that is a raw material of the resin constituting the polymer component, and W1, W2, ..., Wm are the mass fractions of each monomer; wherein, W1 + W2 + ... + Wm = 1.

[0125] The glass transition temperatures of the homopolymers of the monomers in the Fox formula can be found in polymer datasheets, adhesive handbooks, or similar publications. For example, the glass transition temperatures of the homopolymers are as follows: methyl acrylate: 10°C; methyl methacrylate: 105°C; n-butyl acrylate: -54°C; 2-ethylhexyl acrylate: -70°C; glycidyl methacrylate: 41°C; and 2-hydroxyethyl acrylate: -15°C.

[0126] As monomers constituting the aforementioned acrylic resins, examples include (meth)acrylate monomers or their derivatives. For instance, alkyl (meth)acrylates with 1 to 18 carbon atoms in the alkyl group can be listed, specifically including methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Furthermore, (meth)acrylates having a cyclic skeleton can be listed, specifically including cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and (meth)acrylate imide. Further, as monomers containing functional groups, examples include hydroxyl-containing monomers such as hydroxyl-containing monomers such as methyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate; in addition, examples include epoxy-containing monomers such as glycidyl (meth)acrylate. For acrylic resins, acrylic polymers containing hydroxyl structural units are preferred due to their good compatibility with the curing components described later. Furthermore, the aforementioned acrylic polymers can copolymerize acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, etc.

[0127] (Curing components)

[0128] The curing components can be thermosetting components and / or energy-curable components. Therefore, it is possible to make the protective film into a thermosetting and / or energy-curable film.

[0129] By using a thermosetting protective film forming film, even if the protective film forming film is made into a thick film, it can be easily heat-cured, thus forming a thick film of protective film forming film with good protective performance. In the heat curing process, multiple workpieces can be cured together.

[0130] By using energy-curable protective film formation, the protective film can be cured by energy rays in a short time.

[0131] Thermosetting components can include thermosetting resins and thermosetting agents. For example, epoxy resin is preferred as a thermosetting resin.

[0132] As epoxy resins, conventionally known epoxy resins can be used. Specifically, examples of epoxy resins include multifunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether or its hydride, o-cresol phenolic varnish epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, and phenylene skeleton type epoxy resins, etc., which are epoxy compounds with two or more functions in their molecules. These epoxy resins can be used alone or in combination of two or more.

[0133] For a protective film forming film with a total weight of 100 parts by mass, the preferred content of the thermosetting component is 1 to 75 parts by mass, more preferably 2 to 60 parts by mass, and even more preferably 3 to 50 parts by mass. For example, it can be 4 to 40 parts by mass, 5 to 35 parts by mass, or 6 to 30 parts by mass. If the content of the thermosetting resin is above or above the lower limit, the protective film can achieve sufficient adhesion to the workpiece, and the protective film has excellent performance in protecting the workpiece. If it is below or above the upper limit, the preservation stability is excellent when it is made into a roll for storage.

[0134] Thermosetting agents function as curing agents for thermosetting resins, particularly epoxy resins. Preferred thermosetting agents include compounds having two or more functional groups in one 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. Among these functional groups, phenolic hydroxyl groups, amino groups, and acid anhydrides are preferred, and phenolic hydroxyl groups and amino groups are even more preferred.

[0135] Specific examples of phenolic curing agents include multifunctional phenolic resins, biphenyl, phenolic varnish-type phenolic resins, dicyclopentadiene phenolic resins, XYLOC type phenolic resins, and aralkyl phenolic resins. Specific examples of amine curing agents include DICY (dicyandiamide). These curing agents can be used alone or in combination of two or more.

[0136] The content of the thermosetting agent relative to 100 parts by weight of thermosetting resin is preferably 0.1 to 500 parts by weight, more preferably 1 to 200 parts by weight. If the content of the thermosetting agent is above the lower limit mentioned above, sufficient curing can be carried out to obtain adhesion; if it is below the upper limit mentioned above, the moisture absorption rate of the protective film can be suppressed, and the adhesion reliability between the workpiece and the protective film can be improved.

[0137] As an energy-ray curing component, a low-molecular-weight compound (energy-ray polymerizable compound) containing energy-ray polymerizable groups and polymerized and cured upon irradiation by energy rays such as ultraviolet light or electron beams can be used. Specifically, examples of such energy-ray curable components include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxy pentaacrylate, dipentaerythritol hexaacrylate, or acrylates such as 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, low-polyester acrylates, urethane acrylate oligomers, epoxy-modified acrylates, polyether acrylates, and itaconic acid oligomers. Such compounds have at least one polymerizable double bond within their molecules, typically with a weight-average molecular weight of 100–30,000, preferably around 300–10,000. The preferred content of the energy-curable component relative to a protective film forming film with a total weight of 100 (parts by mass) is 1 to 80 parts by mass, more preferably 2 to 70 parts by mass, and even more preferably 3 to 60 parts by mass. For example, it can be 4 to 50 parts by mass or 5 to 40 parts by mass.

[0138] Furthermore, as an energy-ray curing component, an energy-ray curable polymer can be used, which is formed by bonding energy-ray polymerizable groups to the main chain or side chain of the polymer component. Such an energy-ray curable polymer combines the functions of both a polymer component and a curing component.

[0139] The main framework of energy ray-cured polymers is not particularly limited. It can be acrylic polymers, which are commonly used as polymer components, or it can be polyester, polyether, etc. Because it is easy to control the synthesis and physical properties, acrylic polymers are particularly preferred as the main framework.

[0140] The energy-ray polymerizable groups bonded to the main chain or side chains of the energy-ray curable polymer are, for example, groups containing carbon-carbon double bonds that are energy-ray polymerizable, such as (meth)acryloyl groups. These energy-ray polymerizable groups can be bonded to the energy-ray curable polymer via alkylene groups, olefinic groups, or polyolefinic groups.

[0141] The weight-average molecular weight (Mw) of the energy-curable polymer is preferably between 10,000 and 2,000,000, more preferably between 100,000 and 1,500,000. Furthermore, the glass transition temperature (Tg) of the energy-curable polymer is preferably in the range of -60 to 50°C, more preferably in the range of -50 to 40°C, and particularly preferably in the range of -40 to 30°C.

[0142] Energy-curable polymers can be obtained, for example, by reacting an acrylic resin containing functional groups such as hydroxyl, carboxyl, amino, substituted amino, and epoxy groups with a compound containing polymerizable groups, each molecule having 1 to 5 substituents that react with these functional groups and energy-curable carbon-carbon double bonds. Examples of substituents that react with these functional groups include isocyanate groups, glycidyl groups, and carboxyl groups.

[0143] Examples of compounds containing polymerizable groups include (meth)acryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, (meth)acryloyl isocyanate, allyl isocyanate, glycidyl methacrylate, and (meth)acrylic acid.

[0144] The acrylic resin is preferably a copolymer formed from (meth)acrylic acid monomers or their derivatives having functional groups such as hydroxyl, carboxyl, amino, substituted amino, and epoxy groups, and other (meth)acrylic ester monomers or their derivatives that can copolymerize with them.

[0145] (Meth)acrylic acid monomers or their derivatives having functional groups such as hydroxyl, carboxyl, amino, substituted amino, and epoxy groups include, for example, 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate with hydroxyl groups; acrylic acid, methacrylic acid, and itaconic acid with carboxyl groups; and glycidyl methacrylate and glycidyl acrylate with epoxy groups.

[0146] Other (meth)acrylate monomers or their derivatives that can copolymerize with the above-mentioned monomers include, for example, alkyl (meth)acrylates with 1 to 18 carbon atoms in the alkyl group, 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, dicyclopentyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, acrylateimide, etc. Furthermore, the above-mentioned acrylic resins can be copolymerized with vinyl acetate, acrylonitrile, styrene, etc.

[0147] When using energy-ray curable polymers, the energy-ray polymerizable compound can be used simultaneously, as can the polymer component.

[0148] In addition to the polymer and curing components mentioned above, the protective film forming film may also contain the following components.

[0149] (Coloring agent)

[0150] The protective film forming film preferably contains a colorant. By incorporating a colorant into the protective film forming film, infrared radiation and other harmful substances generated by surrounding devices can be shielded when the semiconductor device is installed in the equipment, preventing malfunctions caused by these sources. In semiconductor devices or semiconductor chips with a protective film, product numbers and other markings are typically printed on the surface of the protective film using laser marking. By including a colorant in the protective film, the contrast difference between the laser-marked and unmarked areas of the protective film can be sufficiently obtained, improving recognizability. Organic or inorganic pigments and dyes can be used as colorants. Pigments are preferred from the perspective of heat resistance, etc. Carbon black, iron oxide, manganese dioxide, aniline black, activated carbon, etc., can be used as pigments, but are not limited to these. Among them, carbon black is particularly preferred from the perspective of processability and dispersibility. A single colorant can be used, or two or more can be used in combination.

[0151] The content of colorant is preferably 0.05 to 35 parts by mass relative to 100 parts by mass of all solid components constituting the protective film, more preferably 0.1 to 25 parts by mass, and particularly preferably 0.2 to 15 parts by mass.

[0152] (Curing accelerator)

[0153] Curing accelerators are used to adjust the curing speed of the protective film. It is particularly preferred to use a curing accelerator when both epoxy resin and a thermosetting agent are used in the curing components.

[0154] 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; organophosphorus compounds such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylboronic acid ester. These curing accelerators can be used alone or in combination of two or more.

[0155] Relative to 100 parts by weight of the curing component, it is preferable to contain 0.01 to 10 parts by weight of a curing accelerator, and more preferably 0.1 to 5 parts by weight of a curing accelerator. By containing a curing accelerator in the above range, excellent adhesive properties are achieved even when exposed to high temperature and high humidity, and high adhesive reliability can be achieved even when exposed to severe reflow conditions.

[0156] (Coupled agent)

[0157] Coupling agents can be used to improve the adhesion reliability of protective films to workpieces. Furthermore, by using coupling agents, the water resistance of the protective film obtained through curing can be improved without compromising its heat resistance.

[0158] As a coupling agent, a compound having functional groups that react with the polymer components, curing components, etc., is preferred. A silane coupling agent is most preferably used. Examples of such coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloyloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureapropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, bis(3-triethoxysilylsilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole silane, etc. These coupling agents can be used alone or in combination of two or more.

[0159] The coupling agent is typically contained in a ratio of 0.1 to 20 parts by mass relative to 100 parts by mass of the polymer and curing components, preferably in a ratio of 0.2 to 10 parts by mass, and more preferably in a ratio of 0.3 to 5 parts by mass. If the content of the coupling agent is less than 0.1 parts by mass, the above-mentioned effect may not be achieved, and if it exceeds 20 parts by mass, degassing may occur.

[0160] (Filling material)

[0161] By incorporating filler materials into the protective film, the coefficient of thermal expansion of the cured protective film can be adjusted. Optimizing the coefficient of thermal expansion of the cured protective film for semiconductor chips improves the adhesion reliability between the workpiece and the protective film. Inorganic filler materials are preferred. Furthermore, the moisture absorption rate of the cured protective film can be reduced.

[0162] Preferred inorganic filler materials include powders of silica, alumina, talc, calcium carbonate, titanium dioxide, iron oxide, silicon carbide, and boron nitride, as well as beads formed by spheroidizing these powders, single-crystal fibers, and glass fibers. Among these inorganic filler materials, silica filler and alumina filler are preferred. The above-mentioned inorganic filler materials can be used alone or in combination of two or more. The content of the inorganic filler material relative to 100 parts by mass of all solid components constituting the protective film can be set to 1–85 parts by mass, 5–80 parts by mass, 10–75 parts by mass, 20–70 parts by mass, or 30–66 parts by mass.

[0163] By setting the content of inorganic filler material below the aforementioned upper limit, the risk of cracking (fissures) when the protective film is bent during roll forming can be reduced; by setting it above the aforementioned lower limit, the heat resistance of the protective film can be improved.

[0164] (Photopolymerization initiator)

[0165] When the protective film forming film contains the aforementioned energy-curing component as a curing agent, it is used by irradiating it with energy rays such as ultraviolet light to cure the energy-curing component. In this case, by including a photopolymerization initiator in the composition, the polymerization curing time and the amount of light irradiation can be reduced.

[0166] Examples of 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-hydroxycyclohexylphenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzoyl (benzil), dibenzoyl, diacetyl, 1,2-diphenylmethane, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, and β-chloroanthraquinone. A single photopolymerization initiator can be used, or two or more can be used in combination.

[0167] Regarding the blending ratio of the photopolymerization initiator, relative to 100 parts by mass of the energy-curable component, it is preferable to contain 0.1 to 10 parts by mass of the photopolymerization initiator, more preferably 1 to 5 parts by mass of the photopolymerization initiator. If the ratio is above or below the lower limit, photopolymerization can be carried out to obtain sufficient protective performance; if the ratio is below the upper limit, the formation of residues that are not conducive to photopolymerization can be suppressed, thereby ensuring sufficient curing of the protective film.

[0168] (Cross-linking agent)

[0169] To adjust the adhesion and cohesion between the protective film and the workpiece, a crosslinking agent can be added. Examples of crosslinking agents include organic polyisocyanate compounds and organic polyimide compounds.

[0170] Examples of the aforementioned organic polyisocyanate compounds include aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, trimers of these organic polyisocyanate compounds, and terminal isocyanate carbamate prepolymers obtained by reacting these organic polyisocyanate compounds with polyol compounds.

[0171] Examples of organic polyisocyanate compounds include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-phenylenedimethylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, trimethylolpropane addition toluene diisocyanate, and lysine isocyanate.

[0172] Examples of the aforementioned organic polyimide compounds include N,N'-diphenylmethane-4,4'-bis(1-aziridinylcarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, and N,N'-toluene-2,4-bis(1-aziridinylcarboxamide)triethylene melamine.

[0173] The crosslinking agent is typically used at a ratio of 0.01 to 20 parts by mass relative to the total amount of polymer components and energy-curable polymers (100 parts by mass), preferably at a ratio of 0.1 to 10 parts by mass, and more preferably at a ratio of 0.5 to 5 parts by mass.

[0174] (General Additive)

[0175] In addition to the above-mentioned components, various additives may be incorporated into the protective film as needed. Examples of such additives include tackifiers, leveling agents, plasticizers, antistatic agents, antioxidants, ion trapping agents, impurity absorbers, and chain transfer agents.

[0176] (solvent)

[0177] The protective film forming composition preferably further contains a solvent. The operability of the protective film forming composition becomes better when a solvent is included.

[0178] The solvent is not particularly limited, but preferred solvents include, for example, hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropane-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 with amide bonds) such as dimethylformamide and N-methylpyrrolidone.

[0179] The protective film forming composition may contain only one solvent or two or more solvents. When there are two or more solvents, their combination and ratio can be arbitrarily selected.

[0180] From the perspective of enabling more uniform mixing of the components contained in the composition, the solvent contained in the protective film forming composition is preferably methyl ethyl ketone or the like.

[0181] The protective film formed by coating and drying the aforementioned protective film forming composition has adhesiveness and curability, and can be pressed onto a workpiece in its uncured state. During pressing, the protective film can be heated. After curing, it ultimately provides a protective film with high impact resistance and excellent adhesion, maintaining sufficient protective function even under severe high temperature and high humidity conditions. Furthermore, the protective film can be a single-layer structure or a multi-layer structure containing at least one layer of the aforementioned components.

[0182] The thickness of the protective film is not particularly limited and can be set to 3–300 μm, 3–200 μm, 5–100 μm, 7–80 μm, 10–70 μm, 12–60 μm, 15–50 μm, 18–40 μm, or 20–30 μm.

[0183] If the thickness of the protective film is above the lower limit mentioned above, the protective performance of the protective film can be sufficient. If it is below the upper limit mentioned above, the cost can be reduced. When forming a protective film that can be cured by energy rays, the energy rays can reach the interior.

[0184] (Support plate)

[0185] As a support piece 10, it can be used Figure 4 An adhesive sheet can be formed by laminating an adhesive layer 12 on a substrate 11, or a sheet consisting only of a substrate can be used.

[0186] That is, the support sheet 10 can be composed of one layer (single layer) or multiple layers (two or more layers). When the support sheet is composed of multiple layers, the constituent materials and thicknesses of these multiple layers can be the same or different from each other. As long as the effect of the present invention is not impaired, there is no particular limitation on the combination of these multiple layers.

[0187] In addition, in this specification, when not limited to the support sheet, "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". Furthermore, "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".

[0188] The support plate serves to retain the gas generated by laser irradiation, preventing it from escaping and thus creating gas stagnation. It can also prevent dust from adhering to the surface of the protective film, or act as a transport plate to attach a fixing fixture such as a ring frame to a workpiece with the protective film, allowing a robotic arm to clamp and transport the workpiece without direct contact with the protective film.

[0189] The thickness of the support sheet can be appropriately selected according to the application, but from the perspective of ensuring good adhesion to the workpiece with the protective film and the fixing fixture, it is preferably 10 to 500 μm, more preferably 20 to 350 μm, and even more preferably 30 to 200 μm.

[0190] In addition, the thickness of the aforementioned support sheet is not only the thickness of the substrate constituting the support sheet, but also includes the thickness of these layers or films when an adhesive layer is present, excluding release films that are not attached to the protective film to form a film.

[0191] (Substrate)

[0192] A resin film is preferably used as the substrate for the support sheet.

[0193] Examples of resin films include, for example, low-density polyethylene (LDPE) films or linear low-density polyethylene (LLDPE) films, polyethylene films, ethylene-propylene copolymer films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films (PET films), polyethylene naphthalate films, polybutylene terephthalate films, polyurethane films, ethylene-vinyl acetate copolymer films, ionomer resin films, ethylene-(meth)acrylic acid copolymer films, ethylene-(meth)acrylic acid copolymer films, polystyrene films, polycarbonate films, polyimide films, fluoropolymer films, etc.

[0194] In one embodiment of the present invention, the substrate used can be a single-layer film composed of a single resin film, or a laminated film composed of two or more resin films.

[0195] Furthermore, in one aspect of the present invention, a sheet on which the surface of the aforementioned resin film or other substrate has undergone surface treatment can be used as a support sheet.

[0196] These resin films can also be cross-linked films.

[0197] In addition, films made by coloring these resin films or films that have been printed can also be used. Furthermore, the resin film can be a film obtained by extruding thermoplastic resin into a sheet, a stretched film, or a film made by curing a curable resin into a film and then curing it into a sheet using a specific method.

[0198] Among these resin films, substrates containing polypropylene films are preferred from the perspectives of excellent heat resistance, adaptability due to moderate flexibility, and ease of maintaining pick-up adaptability.

[0199] Furthermore, the composition of the substrate containing the polypropylene film can be a single-layer structure consisting only of the polypropylene film, or a multi-layer structure consisting of the polypropylene film and other resin films.

[0200] When the protective film is thermosetting, the resin film constituting the substrate has heat resistance, which can suppress heat-induced damage to the substrate and prevent adverse events from occurring during the manufacturing process of semiconductor devices.

[0201] 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.

[0202] (Adhesive sheet)

[0203] In one aspect of the present invention, as an adhesive sheet serving as a support sheet 10, an adhesive sheet having an adhesive layer 12 formed of an adhesive on a substrate 11 such as a resin film can be cited as an example. By having an adhesive layer 12, the 180° peel adhesion (β1) between the protective film forming film and the support sheet can be easily adjusted.

[0204] Considering that gas retention is easily formed when laser marking is performed on the protective film, the 180° peel adhesion (β1) between the protective film and the support sheet is preferably less than 4.0 N / 25 mm. Specifically, it can be measured in the following ways.

[0205] (180° peel adhesion between the protective film and the support sheet (β1))

[0206] Prepare a 25mm × 140mm pre-curing test piece, consisting of a protective film forming film and a support sheet laminate. Meanwhile, prepare a sheet formed by attaching double-sided adhesive tape to the surface of a SUS support plate. Next, attach the exposed surface of the protective film forming film of the pre-curing test piece to the support plate via the double-sided adhesive tape, thus attaching the pre-curing test piece to the support plate.

[0207] Then, under the conditions of a peel angle of 180°, a measurement temperature of 23°C, and a tensile speed of 300 mm / min, a tensile test was conducted to peel the support sheet (the laminate of the adhesive layer and the substrate before curing) from the protective film forming film, and the load (peel force) at this time was measured as the 180° peel adhesion force (β1) between the protective film forming film and the support sheet. In addition, the measured value of the load was obtained by removing the measured values ​​of the first 10 mm peel length and the last 10 mm peel length from the effective value when peeling the support sheet for 100 mm.

[0208] Adhesives used as forming materials for adhesive layers include adhesive compositions containing adhesive resins, which may further contain general additives such as crosslinking agents or tackifiers.

[0209] When considering the structure of such adhesive resins, examples include acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyethylene ethers, polycarbonates, and ester resins.

[0210] The 180° peel adhesion (β2) between the protective film formed by the protective film and the support sheet is preferably 0.03 to 4.0 N / 25 mm, more preferably 0.05 to 2.5 N / 25 mm, even more preferably 0.10 to 2.0 N / 25 mm, and even more preferably 0.15 to 1.5 N / 25 mm. By making the 180° peel adhesion (β2) less than 4.0 N / 25 mm, gas retention is easily formed when laser marking is performed on the protective film. Specifically, it can be measured by the following method.

[0211] (180° peel adhesion between the protective film and the support sheet (β2))

[0212] A pre-curing test piece was prepared using the same method as described above for determining the adhesion of the pre-curing test piece, and then attached to the dry-polished surface of a silicon wafer (6 inches in diameter, 600 μm thick, silicon mirror wafer).

[0213] Then, the protective film of the test piece before curing was cured by heating at 130°C for 2 hours to obtain the cured test piece.

[0214] Then, for the cured test piece, the 180° peel adhesion (β2) between the protective film formed by curing the protective film and the support sheet was measured using the same method as for the uncured test piece.

[0215] The 180° peel adhesion (β2) between the protective film and the support sheet can be set to a range of 0.03 N / 25 mm or more and 4.0 N / 25 mm or less.

[0216] In one aspect of the invention, starting from the angle at which the 180° peel adhesion (β2) between the protective film and the support sheet is adjusted to the range described above, and the angle at which good pick-up is achieved, it is preferable to have an adhesive sheet having an adhesive layer with energy-curable adhesive properties formed by an adhesive composition containing an energy-curable resin, or an adhesive sheet having a micro-adhesive adhesive layer.

[0217] As an energy ray curable resin, any resin having polymerizable groups such as (meth)acryloyl or vinyl groups is acceptable, and an adhesive resin having polymerizable groups is preferred.

[0218] Furthermore, starting from the angle that adjusts the 180° peel adhesion (β1) and adhesion (β2) between the protective film forming film and the support sheet to the range mentioned above, an adhesive containing acrylic resin is preferred.

[0219] The acrylic resin is preferably an acrylic polymer having a structural unit (x1) derived from an alkyl methacrylate, and more preferably an acrylic copolymer having a structural unit (x1) and a structural unit (x2) derived from a functional monomer.

[0220] The number of carbon atoms in the alkyl group of the above-mentioned (meth)acrylate is preferably 1 to 18, more preferably 1 to 12, and even more preferably 1 to 8.

[0221] As structural unit (x1) derived from the alkyl methacrylate, the same structural unit as the alkyl methacrylate constituting the above-mentioned acrylic resin can be listed.

[0222] In addition, alkyl (meth)acrylates can be used alone or in combination with two or more.

[0223] The content of structural unit (x1) is typically 50 to 100% by mass relative to all structural units (100% by mass) of the acrylic polymer, preferably 50 to 99.9% by mass, more preferably 60 to 99% by mass, and even more preferably 70 to 95% by mass.

[0224] As structural units (x2) derived from the aforementioned functional group monomers, examples include structural units derived from hydroxyl-containing monomers, carboxyl-containing monomers, epoxy-containing monomers, etc. As specific examples of each monomer, monomers identical to the functional group monomers constituting the aforementioned acrylic resins can be listed.

[0225] In addition, these monomers can be used alone, or two or more can be used simultaneously.

[0226] The content of structural unit (x2) is typically 0 to 40% by mass relative to the total structural units (100% by mass) of the acrylic polymer, preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 5 to 20% by mass.

[0227] Furthermore, as an acrylic resin used in one aspect of the present invention, it can be an energy-curable acrylic resin obtained by further reacting an acrylic copolymer having the above-described structural units (x1) and (x2) with a compound having energy-ray polymerizable groups.

[0228] As a compound with energy-ray polymerizable groups, it is acceptable to use a compound with polymerizable groups such as (meth)acryloyl or vinyl groups.

[0229] When using an adhesive containing acrylic resin, it is preferable to contain a crosslinking agent in addition to acrylic resin, starting from the angle that adjusts the 180° peel adhesion (β1) and adhesion (β2) between the protective film forming film and the support sheet to the range mentioned above.

[0230] Examples of crosslinking agents include isocyanate crosslinking agents, imine crosslinking agents, epoxy crosslinking agents, oxazoline crosslinking agents, and carbodiimide crosslinking agents. From the perspective of adjusting the 180° peel adhesion (β1) and adhesion (β2) between the protective film forming film and the support sheet to the above-mentioned range, isocyanate crosslinking agents are preferred.

[0231] The content of crosslinking agent is preferably 1 part by mass or more, more preferably 3 to 50 parts by mass, further preferably 5 to 40 parts by mass, and even more preferably 10 to 30 parts by mass, relative to the total mass (100 parts by mass) of acrylic resin contained in the adhesive.

[0232] In the manufacturing method of the workpiece with a protective film according to the first embodiment, the protective film forming film 13 is attached to the outer periphery with a clamping adhesive layer 16, and is fixed to the fixing clamp 18 (e.g., annular frame) via the clamping adhesive layer 16. When the adhesive layer 12 of the support piece 10 has sufficient adhesion to the fixing clamp 18, it is not necessary to have a clamping adhesive layer 16, and the adhesive layer 12 of the support piece 10 can be directly fixed to the fixing clamp 18.

[0233] The support sheet is preferably one that can transmit laser light within the laser wavelength used in laser marking.

[0234] When the protective film forming film has energy ray curing properties, the support sheet is preferably a support sheet that can transmit energy rays.

[0235] For example, in order to perform optical inspection of the protective film formed through the support sheet, the support sheet is preferably transparent.

[0236] From the perspective of ensuring good processability, the support sheet can have a release film before it is attached to the protective film forming film.

[0237] <Second Implementation Method for Manufacturing a Workpiece with a Protective Film>

[0238] In the manufacturing method of a workpiece with a protective film according to the second embodiment of the present invention, a first laminate containing a workpiece and a protective film is formed; the protective film of the first laminate is cured to form a second laminate containing a workpiece and a protective film; a support sheet is attached to the protective film of the second laminate to form a fourth laminate containing a workpiece, a protective film, and a support sheet; the protective film of the fourth laminate is irradiated with a laser from the support sheet side, thereby creating gas retention between the protective film and the support sheet while laser marking is performed on the surface of the protective film on the support sheet side.

[0239] Figure 10A and Figure 10B A cross-sectional schematic diagram illustrating an example of a method for manufacturing a workpiece with a protective film according to the second embodiment.

[0240] Semiconductor wafers and other workpieces 14 (with circuit surface protective tape 17 attached) are prepared for mounting on circuit surface 14a. Figure 10A (a)). A protective film 13 is formed by stacking a protective film on the back side 14b of a workpiece 14, such as a semiconductor wafer having a circuit surface 14a. Figure 10A (b) in the middle → Figure 10A (c)). The second peeling membrane 152 is peeled off as needed. Figure 10A (c) in Figure 10A (d) Further, the protective tape 17 for the circuit surface is peeled off to form a first laminate 5 having the workpiece 14 and the protective film forming film 13 stacked together. Figure 10B (e) in the middle.

[0241] The protective tape 17 for circuit surfaces can be applied before the laminated protective film 13 is formed. Figure 10A (a) in Figure 10A (b) between them.

[0242] The protective film 13 of the first laminate 5 is cured. Figure 10B (f) in the middle, forming a second laminate 6 with workpiece 14 and protective film 13' stacked. Figure 10B(g)). Through curing treatment, the protective film forming film 13 becomes the protective film 13'. The protective film forming film 13 can be thermosetting or energy-curable. If the protective film forming film 13 is thermosetting, the curing treatment is a thermosetting treatment; if the protective film forming film 13 is energy-curable, the curing treatment is an energy-curable treatment.

[0243] A support sheet 10, consisting only of a substrate, is attached to the protective film 13' of the second laminate 6, forming a fourth laminate 19' in which the workpiece 14, the protective film 13', and the support sheet 10 are sequentially stacked. Figure 10B (h)). The protective film 13' of the fourth laminate 19' is irradiated with laser from the support sheet 10 side. Figure 10B In (i), gas is trapped between the protective film 13' and the support sheet 10, and laser marking is performed on the surface of the support sheet 10 side of the protective film 13', thereby manufacturing a workpiece 14 with a laser-marked protective film 13'.

[0244] In the manufacturing method of the workpiece with a protective film according to the second embodiment, a gas trap 30 is formed between the support sheet 10, which is made of only a substrate, and the protective film 13'. Therefore, when operating on the workpiece with the protective film after laser marking, the laser marking on the protective film 13' can be appropriately shielded, and the leakage of information from the laser marking can be prevented even by manual operation.

[0245] In the manufacturing method of the workpiece with protective film in the second embodiment, the support sheet 10 uses a sheet made of only a substrate. However, similar to the manufacturing method of the workpiece with protective film in the first embodiment, an adhesive sheet formed by laminating an adhesive layer on a substrate can also be used.

[0246] <Manufacturing method of workpiece with protective film according to the third embodiment>

[0247] In the manufacturing method of a workpiece with a protective film according to the third embodiment of the present invention, a first laminate containing a workpiece and a protective film forming film is formed. A support sheet is attached to the protective film forming film of the first laminate to form a third laminate containing a workpiece, a protective film forming film, and a support sheet in sequence. The protective film forming film of the third laminate is cured to form a fourth laminate containing a workpiece, a protective film, and a support sheet in sequence. The protective film of the fourth laminate is irradiated with a laser from the support sheet side, thereby creating gas retention between the protective film and the support sheet while laser marking is performed on the surface of the protective film on the support sheet side.

[0248] Figure 11A cross-sectional schematic diagram illustrating an example of the manufacturing method of a workpiece with a protective film according to the third embodiment up to the formation of the third laminate 19.

[0249] Semiconductor wafers and other workpieces 14 (with circuit surface protective tape 17 attached) are prepared for mounting on circuit surface 14a. Figure 11 (a)). A protective film 13 is formed by stacking a protective film on the back side 14b of a workpiece 14, such as a semiconductor wafer having a circuit surface 14a. Figure 11 (b) in the middle → Figure 11 (c)). Peel off the second peeling membrane 152 ( Figure 11 (c) in Figure 11 (d)). Further, a support sheet 10 consisting only of a substrate is attached to the second surface 13b of the protective film forming film 13 on the side opposite to the workpiece 14, forming a third laminate 19 in which the workpiece 14, the protective film forming film 13, and the support sheet 10 are sequentially stacked. Figure 11 (e) in Figure 11 (f)). In addition, the protective tape 17 for the circuit surface should be peeled off as needed.

[0250] The subsequent processes in the manufacturing method of the workpiece with a protective film according to the third embodiment are the same as those described in the first embodiment. Figures 1D to 1G The same. The protective film forming film 13 of the third laminate 19 is cured to form a fourth laminate 19', in which the workpiece 14, the protective film 13', and the support sheet 10 are sequentially stacked. Figure 1D → Figure 1E Laser irradiation is applied to the protective film 13' of the fourth laminate 19' from the support sheet 10 side, thereby creating gas retention between the protective film 13' and the support sheet 10, while simultaneously laser marking is applied to the surface of the protective film 13' on the support sheet 10 side of the fourth laminate 19'. Figure 1F , Figure 1G ).

[0251] In the manufacturing method of the workpiece with a protective film according to the third embodiment, a gas stagnation 30 is formed between the support sheet 10 and the protective film 13'. Therefore, when operating on the workpiece with the protective film after laser marking, the laser marking on the protective film 13' can be appropriately shielded, and the leakage of information from the laser marking can be prevented even by manual operation.

[0252] In the third embodiment of the manufacturing method of the workpiece with a protective film, the support sheet 10 uses a sheet made only of a substrate. However, similar to the first embodiment of the manufacturing method of the workpiece with a protective film, an adhesive sheet with an adhesive layer laminated on the substrate can also be used as the support sheet 10.

[0253] In the manufacturing method of the workpiece with a protective film of the present invention, the workpiece with the protective film is subjected to pressure treatment or heat treatment as needed. Figure 5 This can cause the gas to become trapped and disappear. Figure 6 By eliminating the gas retention, it is possible to prevent the chip from scattering during subsequent cutting or cleaning processes, and the laser markings formed on the first surface 13a' of the support sheet 10 side of the protective film 13' can be identified through the support sheet 10.

[0254] For pressurization or heating treatment of workpieces with protective films, there are no limitations as long as the conditions allow for the elimination of trapped gas. The maximum pressure can be 0.1–1.0 MPa, preferably 0.2–0.9 MPa, more preferably 0.3–0.8 MPa, and even more preferably 0.4–0.7 MPa. The maximum pressure time is preferably 5–1000 min, more preferably 10–800 min, and even more preferably 20–600 min. The temperature can be 23–200 °C, preferably 30–180 °C, more preferably 50–180 °C, and even more preferably 70–150 °C. The pressurization or heating treatment time is preferably 5–1000 min, more preferably 10–800 min, and even more preferably 20–600 min. However, the case of normal temperature and pressure (i.e., 0.1 MPa and 23 °C) is excluded.

[0255] For pressurization or heating treatment of workpieces with protective films, the integral value of the pressurization time [min] of "pressure [MPa] - atmospheric pressure 0.1MPa" is preferably 1.0 to 500MPa·min, more preferably 2.0 to 300MPa·min, and even more preferably 4.0 to 300MPa·min.

[0256] <<Manufacturing Method of Workpiece with Protective Film Formation>>

[0257] In the manufacturing method of the workpiece with protective film forming film of the present invention, a third laminate consisting of a workpiece, a protective film forming film and a support sheet are formed in sequence. The protective film forming film of the third laminate is laser-irradiated from the support sheet side, thereby forming gas retention between the protective film forming film and the support sheet, and laser marking is performed on the surface of the protective film forming film on the support sheet side.

[0258] In the manufacturing method of the workpiece with a protective film forming film of the present invention, the protective film forming film of the third laminate is laser-irradiated from the support sheet side, thereby creating gas retention between the protective film forming film and the support sheet, and simultaneously laser-marking the surface of the protective film forming film on the support sheet side. Therefore, when operating the workpiece with the laser-marked protective film forming film, the laser marking on the protective film forming film can be shielded, and information leakage of the laser marking can be prevented even by manual operation.

[0259] For gas retention formed in a workpiece with a protective film, the number of characters in the text of the evaluation object that come into contact with the gas retention can be counted and evaluated using the gas retention rate defined by the following formula.

[0260] Gas retention rate (%) = (Number of characters in contact with gas retention area / Total number of characters) × 100

[0261] The gas retention rate formed in the workpiece with the protective film is preferably 10% or more, more preferably 20% or more, even more preferably 35% or more, even more preferably 60% or more, and particularly preferably 80% or more.

[0262] <Method for manufacturing a workpiece with a protective film forming film according to the first embodiment>

[0263] In the manufacturing method of a workpiece with a protective film forming film according to the first embodiment of the present invention, a composite sheet for forming a protective film is formed, which is stacked with a protective film forming film and a support sheet.

[0264] A workpiece is attached to the protective film forming film of the composite sheet for forming the protective film, thereby forming a third laminate in which the workpiece, the protective film forming film, and the support sheet are sequentially stacked.

[0265] Laser irradiation is performed on the protective film forming film of the third laminate from the support sheet side, thereby creating gas retention between the protective film forming film and the support sheet, and simultaneously laser marking is performed on the surface of the protective film forming film on the support sheet side.

[0266] Hereinafter, the manufacturing method of a workpiece with a protective film forming film applied according to the first embodiment of the present invention will be described in detail with reference to the accompanying drawings. Figures 7A to 7E A cross-sectional schematic diagram illustrating an example of a method for manufacturing a workpiece with a protective film forming according to this embodiment.

[0267] First, a protective film forming film 13 is laminated on the adhesive layer 12 of the support sheet 10, which is formed by laminating the adhesive layer 12 onto the substrate 11. Then, an annular clamping adhesive layer 16 is laminated on the periphery of the protective film forming film 13 on the side opposite to the support sheet 10, thereby producing a protective film forming composite sheet 1. Figure 7A ).

[0268] Semiconductor wafers or other workpieces 14 are attached to the protective film forming film 13 of the composite sheet 1 for forming a protective film, thereby forming a third laminate 19 in which the workpiece 14, the protective film forming film 13, and the support sheet 10 are sequentially stacked. Figure 7B ). Figure 2 This is a top view of the third laminate 19 with the workpiece 14 attached to the composite sheet 1 for forming the protective film. The clamping layer 16 of the third laminate 19 is attached to the fixing clamp 18 (e.g., annular frame). Figure 7C ).

[0269] Laser irradiation is applied to the protective film forming film 13 of the third laminate 19 from the support sheet 10 side, thereby creating a gas retention 30 between the protective film forming film 13 and the support sheet 10, while simultaneously laser marking is applied to the surface of the protective film forming film 13 on the support sheet 10 side. Figure 7D This enables the manufacture of a workpiece 14 with a protective film 13 formed after laser marking. Figure 7E ).

[0270] Conventionally, the output power for laser marking on the protective film forming film 13 is affected by factors such as the size of the text or the materials contained in the protective film forming film, and is, for example, 0.1 to 0.3 W. In order to form a gas retention 30 between the protective film forming film 13 and the support sheet 10 to properly shield the laser marking on the protective film forming film 13, the output power for laser marking is preferably 0.42 W or more, more preferably 0.45 W or more, and even more preferably 0.48 W or more.

[0271] In the manufacturing method of the workpiece with a protective film forming film according to the first embodiment, a gas retention 30 is formed between the adhesive layer 12 of the support sheet 10 and the protective film forming film 13. Therefore, in the workpiece with the protective film forming film after laser marking, the laser marking of the protective film forming film 13 can be appropriately shielded, and the information leakage of the laser marking can be prevented even by manual operation.

[0272] For gas retention formed in a workpiece with a protective film, the number of characters in the text of the evaluation object that come into contact with the gas retention can be counted and evaluated using the gas retention rate defined by the following formula.

[0273] Gas retention rate (%) = (Number of characters in contact with gas retention area / Total number of characters) × 100

[0274] The gas retention rate formed in the workpiece with the protective film is preferably 10% or more, more preferably 20% or more, even more preferably 35% or more, even more preferably 60% or more, and particularly preferably 80% or more.

[0275] As needed, the protective film forming film 13 of the workpiece with a protective film forming film manufactured by the manufacturing method of this embodiment can be cured to form a fourth laminate 19' in which the protective film 13' and the support sheet 10 are stacked sequentially. Through curing, the protective film forming film 13 becomes the protective film 13'. If the protective film forming film 13 is thermosetting, the curing process is a thermosetting process; if the protective film forming film 13 is energy-curable, the curing process is an energy-curable process.

[0276] If the protective film forming film is energy-curable, then the gas formed in the workpiece with the protective film forming film can remain and not disappear during the energy-curing process, which is preferred.

[0277] <Second Implementation Method for Manufacturing a Workpiece with a Protective Film Formation>

[0278] In the manufacturing method of a workpiece with a protective film forming film according to the second embodiment of the present invention, a first laminate containing a workpiece and a protective film forming film is formed. A support sheet is attached to the protective film forming film of the first laminate to form a third laminate containing a workpiece, a protective film forming film, and a support sheet in sequence. The protective film forming film of the third laminate is irradiated with a laser from the support sheet side, thereby creating gas retention between the protective film forming film and the support sheet, and simultaneously laser marking is performed on the surface of the protective film forming film on the support sheet side.

[0279] Figure 11 A cross-sectional schematic diagram illustrating an example of a method for manufacturing a workpiece with a protective film forming a film according to the second embodiment up to the formation of the third laminate 19.

[0280] Semiconductor wafers and other workpieces 14 (with circuit surface protective tape 17 attached) are prepared for mounting on circuit surface 14a. Figure 11 (a)). A protective film 13 is formed by stacking a protective film on the back side 14b of a workpiece 14, such as a semiconductor wafer having a circuit surface 14a. Figure 11 (b) in the middle → Figure 11 (c)). Peel off the second peeling membrane 152 ( Figure 11 (c) in Figure 11(d)). Further, a support sheet 10 consisting only of a substrate is attached to the second surface 13b of the protective film forming film 13 on the side opposite to the workpiece 14, forming a third laminate 19 in which the workpiece 14, the protective film forming film 13, and the support sheet 10 are sequentially stacked. Figure 11 (e) in Figure 11 (f)). In addition, the protective tape 17 for the circuit surface should be peeled off as needed.

[0281] Then, the protective film forming film 13 of the third laminate 19 is laser-irradiated from the support sheet 10 side, thereby creating gas retention between the protective film forming film 13 and the support sheet 10, and simultaneously laser-marking the surface of the protective film forming film 13 on the support sheet 10 side. The above operations are the same as those described in the first embodiment. Figures 7D to 7E same.

[0282] In the manufacturing method of the workpiece with a protective film forming film according to the second embodiment, a gas retention 30 is formed between the support sheet 10, which is made of only a substrate, and the protective film forming film 13. Therefore, in the workpiece with the protective film forming film after laser marking, the laser marking on the protective film forming film 13 can be appropriately shielded, and the leakage of information from the laser marking can be prevented even by manual operation.

[0283] In the manufacturing method of the workpiece with protective film forming film in the second embodiment, the support sheet 10 uses a sheet made of only substrate. However, similar to the manufacturing method of the workpiece with protective film in the first embodiment, an adhesive sheet with an adhesive layer laminated on the substrate can also be used.

[0284] In the manufacturing method of the workpiece with a protective film forming film of the present invention, the workpiece with the protective film forming film can be subjected to pressure treatment or heat treatment as needed. Figure 8 This causes the gas retention to disappear. Figure 9 By eliminating the gas retention, it is possible to prevent the chip from scattering during subsequent cutting or cleaning processes, and to identify the laser markings formed on the first surface 13a of the protective film forming film 13 on the support sheet 10 side through the support sheet 10.

[0285] The pressure treatment or heating treatment of the workpiece with the protective film formed is not particularly limited as long as the conditions are sufficient to eliminate gas retention. The maximum pressure can be 0.1–1.0 MPa, preferably 0.2–0.9 MPa, more preferably 0.3–0.8 MPa, and even more preferably 0.4–0.7 MPa. The maximum pressure time is preferably 5–1000 min, more preferably 10–800 min, and even more preferably 20–600 min. The temperature can be 23–200 °C, preferably 30–180 °C, more preferably 50–180 °C, and even more preferably 70–150 °C. The pressure or heating treatment time is preferably 5–1000 min, more preferably 10–800 min, and even more preferably 20–600 min. However, the case of normal temperature and pressure (i.e., 0.1 MPa and 23 °C) is excluded.

[0286] For the pressurization or heating treatment of workpieces with protective film forming, the integral value of the pressurization time [min] of "pressure [MPa] - atmospheric pressure 0.1MPa" is preferably 1.0 to 500MPa·min, more preferably 2.0 to 300MPa·min, and even more preferably 4.0 to 300MPa·min.

[0287] After curing the protective film forming film of the workpiece produced by the manufacturing method of the present invention, the workpiece with the protective film forming film can be subjected to pressure treatment or heat treatment as needed, thereby causing the gas retention to disappear. The conditions for pressure treatment or heat treatment are the same as those for pressure treatment or heat treatment of the workpiece with the protective film.

[0288] <<Cutting and Picking Up Workpieces with Protective Film Formation>>

[0289] The workpiece with the protective film formed by the manufacturing method of this embodiment can be cut using conventional methods, and the chip with the protective film formed can be picked up from the support sheet 10. The protective film formed by the chip with the protective film formed can be cured to form a chip with a protective film.

[0290] Cutting can be performed before laser marking, but it is preferable to cut after laser marking. Due to the effects of cutting, the shape of the workpiece changes before and after cutting; for example, a circular semiconductor wafer may experience circular deformation. If laser marking is performed after cutting, it may be impossible to mark the workpiece in the intended position. By performing laser marking before cutting, the intended position can be achieved.

[0291] Even workpieces that are individually produced through cutting are considered "workpieces" as long as the individual individual products are kept in an orderly arrangement. For example, when a workpiece that is a semiconductor wafer is cut to make a semiconductor chip, the assembly of the original semiconductor chips is considered a "workpiece" as long as the original assembly of semiconductor chips maintains a shape that is roughly the same as the semiconductor wafer.

[0292] Example

[0293] The present invention will now be described in detail through specific embodiments. However, the present invention is not limited to any of the embodiments shown below.

[0294] [Preparation of the protective film forming composition]

[0295] The following components are mixed at the mixing ratios shown in Table 1 (conversion of solid components) and diluted with methyl ethyl ketone to a solid component concentration of 61% by mass relative to the total mass of the protective film forming composition, thereby preparing a protective film forming composition for forming a protective film for semiconductor wafers.

[0296] (A-1) Polymer composition: An acrylic polymer (weight average molecular weight: 400,000, glass transition temperature: -1℃) is formed by copolymerizing 70 parts by mass of methyl acrylate, 10 parts by mass of n-butyl acrylate, 5 parts by mass of glycidyl methacrylate and 15 parts by mass of 2-hydroxyethyl acrylate.

[0297] (B-1) Bisphenol A type epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation, which is liquid at 23°C·1atm, has a molecular weight of 370, a softening point of 93°C, and an epoxy equivalent of 183~194g / eq)

[0298] (B-2) Bisphenol A type epoxy resin ("jER1055" manufactured by Mitsubishi Chemical Corporation, which is solid at 23℃·1atm, has a molecular weight of 1600 and an epoxy equivalent of 800~900g / eq)

[0299] (B-3) Dicyclopentadiene type epoxy resin (“EPICLON HP-7200HH” manufactured by DIC Corporation, which is solid at 23°C·1 atm, has a softening point of 88~98°C, and an epoxy equivalent of 255~260 g / eq)

[0300] (C-1) Thermally active latent epoxy resin curing agent (dicyandiamide (ADEKA HARDENER EH-3636AS manufactured by ADEKA CORPORATION, with an active hydrogen content of 21 g / eq))

[0301] (D-1) Curing accelerator: 2-phenyl-4,5-dihydroxymethylimidazole ("CUREZOL 2PHZ" manufactured by SHIKOKU CHEMICALS CORPORATION)

[0302] (E-1) Silica filler ("SC2050MA" manufactured by ADMATECHS CORPORATION, average particle diameter of 0.5 μm)

[0303] (F-1) Colorant: carbon black ("MA600B" manufactured by Mitsubishi Chemical Corporation, average particle diameter of 28 nm)

[0304] (G-1) Silane coupling agent ("KBM403" manufactured by Shin-Etsu Chemical Co., Ltd.)

[0305] Herein, the weight average molecular weight (Mw) of the polymer component (A) is a weight average molecular weight in terms of standard polystyrene, which is measured by gel permeation chromatography (GPC) under the following conditions (GPC measurement).

[0306] <GPC Measurement Conditions>

[0307] Column: A structure formed by sequentially connecting 2 pieces of TSKgel GMHXL and TSKgel 2000HXL.

[0308] Solvent: THF

[0309] Measurement temperature: 40°C

[0310] Flow rate: 1 ml / min

[0311] Detector: Differential refractometer

[0312] Standard sample: Polystyrene

[0313] [Table 1]

[0314]

[0315] [Production of Protective Film Forming Sheet]

[0316] A first release film (manufactured by Lintec Corporation, SP-PET382150, 38 μm thick) is prepared, which is formed by forming an organosilicon release agent layer on one side of a polyethylene terephthalate (PET) film, and a second release film (manufactured by Lintec Corporation, SP-PET381031, 38 μm thick) is prepared, which is formed by forming an organosilicon release agent layer on one side of a PET film.

[0317] The protective film forming composition described above is applied to the release surface of the first release film 151 using a doctor blade coater to achieve a final protective film thickness of 25 μm. It is then dried in an oven at 120°C for 2 minutes to form the protective film forming film 13. The release surface of the second release film 152 is then overlapped onto the protective film forming film 13 and the two are bonded together to obtain a protective film forming sheet 4 composed of the first release film 151, the protective film forming film 13 (thickness: 25 μm), and the second release film 152. Figure 3 ).

[0318] [Manufacturing of the support sheet]

[0319] (Adhesive composition)

[0320] An adhesive composition for manufacturing a support sheet is prepared by mixing (h) and (i) with the following ingredients (converted to solid components) to dilute with methyl ethyl ketone to a solid component concentration of 25% by mass.

[0321] (h) Adhesive: 100 parts by weight of (meth)acrylate copolymer (a copolymer obtained by copolymerizing 60 parts by weight of 2-ethylhexyl acrylate, 30 parts by weight of methyl methacrylate and 10 parts by weight of 2-hydroxyethyl acrylate, weight average molecular weight: 600,000)

[0322] (i) Crosslinking agent: 20 parts by weight of xylene diisocyanate adduct of trimethylolpropane (manufactured by Mitsui Takeda Kemikal Co., Ltd., product name "TAKENATE D110N")

[0323] (Support plate)

[0324] As a release film, a release film with a thickness of 38 μm is prepared, which is formed by forming an organosilicon release agent layer on one side of a PET film (manufactured by Lintec Corporation, product name "SP-PET381031").

[0325] First, the aforementioned adhesive composition is applied to the release surface of the release film using a doctor blade coater to achieve a final adhesive layer thickness of 5 μm, and then dried to form an adhesive layer. Next, an 80 μm thick uncolored polypropylene film (melting point 156°C, matte finish (surface roughness (Ra): 0.20 μm) / micro-matte finish (surface roughness (Ra): 0.15 μm)) is bonded to the exposed surface of this adhesive layer, resulting in a support sheet with a release film structure of substrate / adhesive layer / release film.

[0326] [Preparation of adhesive sheets for clamps]

[0327] An adhesive composition for clamps is prepared by mixing (j) and (k) below with the following components (converted to solid components) and diluting with methyl ethyl ketone to a solid component concentration of 15% by mass.

[0328] (j) Adhesive: 100 parts by weight of (meth)acrylate copolymer (a copolymer obtained by copolymerizing 69.5 parts by weight of butyl acrylate, 30 parts by weight of methyl acrylate and 0.5 parts by weight of 2-hydroxyethyl acrylate, weight average molecular weight: 500,000)

[0329] (k) Crosslinking agent: 5 parts by weight of toluene diisocyanate crosslinking agent (manufactured by TOSOH CORPORATION, product name "CORONATE L")

[0330] A first release film (manufactured by Lintec Corporation, SP-PET382150, 38μm thick) is prepared by forming an organosilicon release agent layer on one side of a polyethylene terephthalate (PET) film, and a second release film (manufactured by Lintec Corporation, SP-PET381031, 38μm thick) is prepared by forming an organosilicon release agent layer on one side of a PET film.

[0331] The aforementioned adhesive composition for clamps was applied to the release surface of the first release film using a doctor blade coater to achieve a final adhesive layer thickness of 20 μm. The mixture was then dried in an oven at 120°C for 2 minutes to form the adhesive layer for clamps. Next, the release surface of the second release film was overlapped onto the adhesive layer for clamps, and the two were bonded together to obtain a laminate (adhesive sheet for clamps) consisting of the first release film, the adhesive layer for clamps (thickness: 20 μm), and the second release film.

[0332] [Fabrication of composite sheets for protective film formation]

[0333] The second release film 152 is peeled off from the protective film forming sheet 4 to expose the protective film forming film 13. On the other hand, the release film is peeled off from the support sheet with the release film to expose the adhesive layer. The support sheet and the protective film forming sheet are bonded together in such a way that the protective film forming film contacts the adhesive layer, to obtain a composite sheet consisting of a support sheet, a protective film forming film, and a first release film, which are composed of a substrate and an adhesive layer.

[0334] Peel the second release film off the adhesive sheet for the fixture, leaving the first release film. Then, cut the inner periphery of the adhesive layer for the fixture in half to remove the inner circular portion. At this point, the diameter of the inner periphery of the adhesive layer for the fixture is 170 mm.

[0335] Peel the first release film from the composite sheet, removing the exposed protective film forming film and the inner circular portion. Overlap this with the exposed clamping adhesive layer and press it together. Then, leaving the first release film with the clamping adhesive layer remaining, halve the outer perimeter of the composite sheet with the clamping adhesive layer, removing the outer portion. At this point, the diameter of the outer perimeter of the composite sheet with the clamping adhesive layer is 205 mm.

[0336] Through the above method, a composite sheet for forming a protective film is obtained. This composite sheet comprises an adhesive sheet (i.e., a support sheet) formed by laminating an adhesive layer (thickness: 5 μm) on a substrate, a protective film forming film laminated on the adhesive layer side of the adhesive sheet, an annular clamping adhesive layer laminated on the peripheral portion of the protective film forming film on the side opposite to the adhesive sheet, and a release film laminated on the side of the clamping adhesive layer on the side opposite to the protective film forming film. This composite sheet for forming a protective film is equivalent to having a release film. Figure 1A The structure.

[0337] (180° peel adhesion between the protective film and the support sheet (β1))

[0338] A composite sheet consisting of a stacked support sheet, a protective film forming film, and a first release film is cut to a size of 25mm × 140mm. The first release film is removed from the composite sheet, exposing one surface of the protective film forming film, thus creating a pre-curing test sheet. Meanwhile, a sheet made by laminating double-sided adhesive tape onto the surface of a SUS-made support plate (70mm × 150mm) is prepared. Next, using a laminator (FUJI Corporation's "LAMIPACKER LPD3214"), the exposed surface of the protective film forming film of the pre-curing test sheet is attached to the double-sided adhesive tape on the support plate, thereby attaching the pre-curing test sheet to the support plate via the double-sided adhesive tape.

[0339] Then, using a precision universal testing machine ("autograph AG-IS" manufactured by Shimadzu Corporation), a tensile test was conducted to peel the support sheet (the laminate of the adhesive layer and the substrate before curing) from the protective film forming film under the conditions of a peel angle of 180°, a test temperature of 23°C, and a tensile speed of 300 mm / min. The load (peel force) at this time was measured as the 180° peel adhesion force (β1) between the protective film forming film and the support sheet. In addition, the measured value of the load was obtained by subtracting the measured values ​​for peeling the first 10 mm length and the last 10 mm length from the effective value when peeling the support sheet for 100 mm length.

[0340] The 180° peel adhesion (β1) between the protective film and the support sheet is 0.7 N / 25 mm, which is less than 4.0 N / 25 mm.

[0341] (180° peel adhesion between the protective film and the support sheet (β2))

[0342] The pre-curing test piece was attached to the dry-polished surface of a silicon wafer (6 inches in diameter, 600 μm thick, silicon mirror wafer).

[0343] Then, the protective film of the test piece before curing was cured by heating at 130°C for 2 hours to obtain the cured test piece.

[0344] Then, for the cured test piece, the 180° peel adhesion (β2) between the protective film formed by curing the protective film and the support sheet was measured using the same method as for the uncured test piece.

[0345] The 180° peel adhesion (β2) between the protective film and the support sheet is 0.3 N / 25 mm, which is less than 4.0 N / 25 mm.

[0346] [Creating the Third Layer]

[0347] After removing the release film from the composite sheet used to form the protective film ( Figure 1A At 70°C, a protective film formed by the exposed inner side of an adhesive layer is attached to the dry polishing surface of a silicon wafer (6 inches in diameter, 100 μm thick, silicon mirror wafer) using a ring-shaped fixture, thus forming a third stack 19 (i.e., a wafer with a protective film forming composite) consisting of a silicon wafer, a protective film forming film, and a support sheet stacked sequentially. Figure 1B In addition, the exposed clamps of the third laminate 19 are attached to the annular frame with adhesive layer 16 and left to stand for 30 minutes. Figure 1C ).

[0348] [Creating the Fourth Layer]

[0349] The third laminate 19 attached to the annular frame is heated at 130°C for 2 hours to cure the protective film 13, forming the protective film 13'. Figure 1D Thus, a fourth laminate 19' is fabricated, consisting of a silicon wafer, a protective film, and a support sheet stacked sequentially. Figure 1E ).

[0350] [Comparative Example 1, Examples 1-4]

[0351] (Laser marking)

[0352] Using a laser marking device (CSM300M manufactured by EO TECHNICS CO.,LTD.), laser light was irradiated from the support sheet side of the fourth laminate 19' toward the protective film under the following irradiation conditions to laser mark the surface of the protective film. Figure 1F → Figure 1G ).

[0353] <Irradiation conditions>

[0354] Text sequence: 1 line "ABCD" (4 characters in total)

[0355] Spacing between each character: 0.05mm

[0356] The dimensions of each character are: 0.3mm in length × 0.2mm in width.

[0357] Laser wavelength: 532nm

[0358] Draw speed: 100mm / s

[0359] Power: Change the printing position: 0.37W, 0.40W, 0.43W, 0.46W, 0.50W.

[0360] <Evaluation of Gas Retention>

[0361] The observation was performed using a digital microscope ("VHS-1000" manufactured by Keyence Corporation) at 100x magnification, and evaluated according to the following 5 levels (AA to D).

[0362] AA: The gas trapping area is in contact with all four characters. The total area of ​​the gas trapping area is "character length × character width × number of characters" (in this case, it is 0.3mm × 0.2mm × 4 = 0.24mm). 2 )above.

[0363] A: The gas trapping area is in contact with all four characters, but the total area of ​​the gas trapping area is less than "character length × character width × number of characters" (in this case, 0.3mm × 0.2mm × 4 = 0.24mm). 2 ).

[0364] B: Gas stagnation comes into contact with 3 characters.

[0365] C: Gas stagnation comes into contact with 1-2 characters.

[0366] D: No gas retention was observed.

[0367] <Evaluation of Gas Retention Rate>

[0368] The number of characters in the text of the evaluation object that come into contact with the gas retention phase is counted, and the gas retention rate defined by the following formula is calculated.

[0369] Gas retention rate (%) = (Number of characters in contact with the gas retention phase / Total number of characters) × 100

[0370] <Evaluation of Text Recognition>

[0371] Visually observe the sequence of characters "ABCD" under a fluorescent light, through a support plate, and evaluate whether the characters can be recognized according to the following four levels (A to D). The distance between the printed text and the evaluator's eyes is set at 20cm.

[0372] A: None of the four characters can be read.

[0373] B: Unable to read 3 characters.

[0374] C: Unable to read 1-2 characters.

[0375] D: All four characters can be read.

[0376] A, B, and C are judged as "qualified (○)", and D is judged as "unqualified (×)".

[0377] The results are shown in Table 2.

[0378] [Table 2]

[0379]

[0380] In Comparative Example 1, no gas was trapped in the workpiece with protective film after laser marking, and the text was legible. In contrast, in Examples 1-4, gas was trapped in the workpiece with protective film after laser marking, which obscured the text.

[0381] [Examples 5-15]

[0382] [Gas Retention Disappearance Test]

[0383] In the same manner as described in [Fabrication of the Fourth Layer], the third layer 19 was heated at 130°C for 2 hours to prepare multiple fourth layers 19' in which silicon wafers, protective films and support sheets are stacked sequentially. Under the same 0.50W conditions as in Example 4 above, each wafer was laser-marked (the evaluation of gas retention was AA, and the evaluation of text legibility was A(○)).

[0384] The laser-marked workpieces with protective films from Examples 5 to 15 were placed in a heating and pressurizing apparatus (manufactured by Lintec Corporation, RAD-9100) and subjected to pressurization and / or heating treatment at a pressure higher than atmospheric pressure (0.10 MPa) under the conditions described in Tables 3 and 4.

[0385] The pressure was restored to atmospheric pressure, and the gas was removed from the heating and pressurizing device. The gas retention status was evaluated using the same standards as before pressurization. At this point, the evaluation of the disappearance of gas retention was D, which is the best evaluation. The evaluation results of the disappearance of gas retention are shown in Tables 3 and 4.

[0386] [Table 3]

[0387]

[0388] [Table 4]

[0389]

[0390] Compared to Example 15, which did not undergo pressurization or heating treatment, the workpieces with protective films after laser marking in Examples 5-14 can have their gas retention eliminated by undergoing pressurization or heating treatment.

[0391] That is, it can form a shielded state when it is necessary to shield the laser mark, and can remove the shielded state when it is necessary to make the gas stagnation disappear.

[0392] For the workpieces with protective films after laser marking in Examples 11 and 12, the initial evaluation of gas retention disappearance is AA, indicating a reduction in gas retention.

[0393] The initial amount of gas retention can change due to laser printing conditions. For example, if the initial evaluation of gas retention is changed from AA to B, then under the pressure treatment or heating treatment conditions of Examples 11 and 12, the evaluation of gas retention disappearing can also be C or D.

[0394] [Comparative Examples 2-3, Examples 16-18]

[0395] (Laser marking)

[0396] In the same manner as described in [Fabrication of the Third Stack], multiple third stacks 19 (i.e., wafers with a composite sheet for forming a protective film) were prepared, in which silicon wafers, protective film forming films, and support sheets were sequentially stacked. Using a laser marking apparatus (CSM300M manufactured by EO TECHNICS CO.,LTD.), laser light was irradiated onto each protective film forming film from the support sheet side of the third stack 19 under the same irradiation conditions as in Comparative Examples 1 and Examples 1-4, thereby laser marking the surface of the protective film forming film. Figure 7D → Figure 7E ).

[0397] In addition, the evaluation of gas retention, the evaluation of gas retention rate, and the evaluation of text legibility were carried out in the same manner as in Comparative Example 1 and Examples 1 to 4.

[0398] The results are shown in Table 5.

[0399] [Table 5]

[0400]

[0401] For the workpieces with protective film formed after laser marking in Comparative Examples 2 and 3, no gas retention was formed, and the text could be read. In contrast, for the workpieces with protective film formed after laser marking in Examples 16 to 18, gas retention was formed, and the text could be obscured.

[0402] [Examples 19-21]

[0403] [Gas Retention Disappearance Test]

[0404] In the same manner as described in the [Fabrication of the Third Stack], multiple third stacks 19, each consisting of a silicon wafer, a protective film forming film, and a support sheet, are prepared sequentially. Each stack is laser-marked at 0.50W in the same manner as in Example 18 above (the evaluation of gas retention is AA, and the evaluation of text legibility is A(○)).

[0405] The protective films formed after laser marking in Examples 19-21 were placed in a heating and pressurizing apparatus (manufactured by Lintec Corporation, RAD-9100) and pressurized at a pressure higher than atmospheric pressure (0.10 MPa) according to the conditions described in Table 6. A portion of the films were simultaneously heated.

[0406] The pressure was restored to atmospheric pressure, and the gas was removed from the heating and pressurizing device. The gas retention status was evaluated using the same standards as before pressurization. At this point, the evaluation of the disappearance of gas retention was D, which is the best evaluation. The evaluation results of the disappearance of gas retention are shown in Table 6.

[0407] [Table 6]

[0408]

[0409] For the workpieces with protective film formed after laser marking in Examples 19-21, gas retention can be eliminated by applying pressure.

[0410] That is, when it is necessary to shield the laser mark, it can form a shielded state; when it is necessary to make the laser mark readable, it can remove the shielded state by causing the gas to stagnate and disappear.

[0411] Industrial applicability

[0412] The manufacturing method of the workpiece with protective film of the present invention can be used to manufacture semiconductor wafers with protective film, semiconductor chips with protective film, and semiconductor devices with protective film.

Claims

1. A method for manufacturing a workpiece with a protective film, wherein, This forms a fourth layer consisting of a workpiece, a protective film, and a support sheet stacked sequentially. Laser irradiation is performed on the protective film of the fourth laminate from the support sheet side, thereby creating gas retention between the protective film and the support sheet while laser marking is performed on the surface of the protective film on the support sheet side.

2. The method for manufacturing a workpiece with a protective film according to claim 1, wherein, A composite sheet for forming a protective film, comprising a protective film forming film and a support sheet, is formed. A workpiece is attached to the protective film forming film of the composite sheet for forming the protective film, thereby forming a third laminate in which the workpiece, the protective film forming film, and the support sheet are sequentially stacked. The protective film of the third laminate is cured to form the fourth laminate.

3. The method for manufacturing a workpiece with a protective film according to claim 1, wherein, A first laminate is formed, consisting of a workpiece and a protective film. The protective film of the first laminate is cured to form a second laminate containing the workpiece and the protective film. A support sheet is attached to the protective film of the second laminate to form the fourth laminate.

4. The method for manufacturing a workpiece with a protective film according to claim 1, wherein, A first laminate is formed, consisting of a workpiece and a protective film. A support sheet is attached to the protective film forming film of the first laminate to form a third laminate in which the workpiece, the protective film forming film, and the support sheet are sequentially stacked. The protective film of the third laminate is cured to form the fourth laminate.

5. The method for manufacturing a workpiece with a protective film according to any one of claims 1 to 4, wherein, The support sheet has an adhesive layer stacked on the substrate, and the fourth stack consists of the workpiece, the protective film, the adhesive layer, and the substrate stacked in sequence.

6. A method for manufacturing a workpiece with a protective film forming thereon, wherein, A third laminate is formed, consisting of a workpiece, a protective film forming film, and a support sheet stacked sequentially. Laser irradiation is performed on the protective film forming film of the third laminate from the support sheet side, thereby creating gas retention between the protective film forming film and the support sheet, and simultaneously laser marking is performed on the surface of the protective film forming film on the support sheet side.

7. The method for manufacturing a workpiece with a protective film forming film according to claim 6, wherein, A composite sheet for forming a protective film, comprising a protective film forming film and a support sheet, is formed. The workpiece is attached to the protective film forming film of the composite sheet for forming the protective film to form the third laminate.

8. The method for manufacturing a workpiece with a protective film forming film according to claim 6, wherein, A first laminate is formed, consisting of a workpiece and a protective film. A support sheet is attached to the protective film forming film of the first laminate to form a third laminate in which the workpiece, the protective film forming film and the support sheet are stacked in sequence.

9. A method for manufacturing a workpiece with a protective film forming layer according to any one of claims 6 to 8, wherein, The support sheet has an adhesive layer stacked on the substrate, and the third stack consists of the workpiece, the protective film forming film, the adhesive layer, and the substrate stacked sequentially.

10. A method for manufacturing a workpiece with a protective film, wherein, The protective film formed on the workpiece with the protective film formed by the method of any one of claims 6 to 8 is cured after laser marking.

11. A method for manufacturing a workpiece with a protective film, wherein, The protective film formed on the workpiece with the protective film formed by laser marking obtained by the method of claim 9 is subjected to a curing process.

12. A method for manufacturing a workpiece with a protective film, wherein, The workpiece with a protective film obtained by any one of claims 1 to 4 is subjected to pressure treatment or heat treatment to make the gas retention disappear.

13. A method for manufacturing a workpiece with a protective film, wherein, The workpiece with a protective film obtained by the method of claim 5 is subjected to pressure treatment or heat treatment to make the gas retention disappear.

14. A method for manufacturing a workpiece with a protective film forming thereon, wherein, The workpiece with a protective film formed by the method of any one of claims 6 to 8 is subjected to pressure treatment or heat treatment to make the gas retention disappear.

15. A method for manufacturing a workpiece with a protective film forming thereon, wherein, The workpiece with a protective film formed by the method of claim 9 is subjected to pressure treatment or heat treatment to make the gas retention disappear.

16. A method for manufacturing a workpiece with a protective film, wherein, The workpiece with a protective film obtained by the method of claim 10 is subjected to pressure treatment or heat treatment to make the gas retention disappear.

17. A method for manufacturing a workpiece with a protective film, wherein, The workpiece with a protective film obtained by the method of claim 11 is subjected to pressure treatment or heating treatment to make the gas retention disappear.

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