Workpiece processing method

Abstract

To provide a treatment method for stably separating a workpiece by a relatively simple process such as mechanical peeling while improving handleability of the workpiece by introduction of a support and being usable in various treatment processes.SOLUTION: The workpiece treatment method includes a step of laminating the support 11, the temporary fixing material 12, and the workpiece 13 located on the surface of the temporary fixing material 12 opposite to the support 11 side, a step of subjecting the workpiece 13 to at least one treatment selected from heat treatment, machining treatment, wet treatment, and laser processing treatment, and a step of separating the workpiece 13 from the laminate having the workpiece 13 after the treatment. A ratio P1 / P2 of a 10 ° peel strength P2 between the support 11 and the temporary fixing material 12 to a 10 ° peel strength P1 between the temporary fixing material 12 and the workpiece 13, which are measured while keeping an angle formed by the peeled layers at 10 °, is set to 1.1 or more.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a method for processing a workpiece, such as a wafer, while the workpiece is fixed to a support via a temporary fixing material, and more specifically to a processing method in which the introduction of a support improves the handleability of the workpiece, making it possible to use the workpiece in a wide variety of processing processes, while also enabling the workpiece to be stably separated by a relatively simple process such as mechanical peeling. [Background technology]

[0002] In semiconductor manufacturing processes, temporary clamping is often necessary or desirable for workpiece processing due to factors such as the workpiece's thinness or fragility. For example, to achieve high levels of integration in semiconductor devices, thin-grinding of wafers with functional layers for semiconductor devices is widely practiced. However, when grinding to an extremely thin wafer, tape alone is no longer sufficient to support the wafer. Therefore, it has been proposed to temporarily clamp the wafer to a hard carrier (support) via a temporary clamping material before processing it after thin-grinding. A semiconductor manufacturing process using such a support is called a wafer support system. As methods for peeling the support after processing, there have been proposed methods that utilize gas generation from the temporary bonding material (see, for example, Patent Document 1), a peeling method that uses a laser, a peeling method that melts the resin of the temporary bonding material and slides off the carrier, and a method that lifts the carrier from one end and peels it off (mechanical peeling). Mechanical peeling is a cost-effective method because the equipment required is relatively simple. However, due to its principle, mechanical peeling applies peeling forces at least to the workpiece / temporary bond interface and the temporary bond / support interface, making it difficult to achieve stable peeling at the desired interface. If peeling occurs at an unintended interface (e.g., the workpiece / temporary bond interface), problems such as damage to the support or electronic components can occur when the support is peeled. On the other hand, it is possible to increase the adhesive strength at unintended interfaces to prevent peeling from unintended interfaces during mechanical peeling, but if the adhesive strength is increased too much, it will become difficult to peel the temporary bonding material from the workpiece, for example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2014 / 024861 A1 Brochure Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above technical background, an object of the present invention is to provide a method for processing workpieces in a stack state in which the workpieces, such as wafers, are fixed to a support via a temporary fixing material, and which can stably separate the workpieces, such as wafers, from the stack by a relatively simple process such as mechanical peeling. [Means for solving the problem]

[0005] As a result of extensive research, the inventors have discovered that in a method for processing workpieces in the form of a stack in which workpieces such as wafers are fixed to a support body via a temporary bonding material, when the peel strength between the support body and the temporary bonding material and the peel strength between the temporary bonding material and the workpiece, measured under specific conditions, satisfy specific conditions, the workpieces such as wafers can be stably separated from the stack by a relatively simple process such as mechanical peeling, and have completed the present invention. That is, the present invention provides: [1] A step (1) of stacking a support (A), a temporary bonding material (B), and a work (C) located on the side of the temporary bonding material (B) opposite to the support (A); A step (2) of subjecting the workpiece (C) to at least one treatment selected from heat treatment, mechanical processing, wet processing, and laser processing; A step (3) of separating the work (C) from the laminate (D) having the treated work (C); A method for processing a workpiece, comprising: a method for treating a workpiece, wherein the ratio of the 10° peel strength P1 between the support (A) and the temporary fixing material (B) to the 10° peel strength P2 between the temporary fixing material (B) and the workpiece (C), P2 / P1, measured while maintaining the angle between the peeled layers at 10°, is 1.1 or more; Regarding.

[0006] Below, [2] to

[13] are each a preferred aspect or embodiment of the present invention. [2] The method for treating a workpiece according to [1], wherein the peel strength P1 is 10 N / 25 mm or less. [3] The method for treating a workpiece according to [1] or [2], wherein the temporary bonding material (B) has a different composition between the adhesive layer in contact with the support (A) and the adhesive layer in contact with the workpiece (C). [4] A method for processing a workpiece according to any one of [1] to [3], wherein the separation of the workpiece (C) from the laminate (D) is achieved by separating the support (A) from the temporary bonding material (B), and then removing the temporary bonding material (B) remaining on the workpiece (C). [5] The method for processing a workpiece according to [4], wherein the method for separating the temporary bonding material (B) and the support (A) is mechanical peeling. [6] The method for treating a workpiece according to any one of [1] to [5], wherein the temporary fixing material (B) contains a curable adhesive component. [7] The method for treating a workpiece according to any one of [1] to [5], wherein the temporary bonding material (B) contains a release agent. [8] The method for treating a workpiece according to any one of [1] to [7], wherein the temporary bonding material (B) is a base film (B0) having adhesive materials laminated on both sides thereof. [9] The method for treating a workpiece according to any one of [1] to [8], wherein the thickness of the workpiece (C) after treatment in step (2) is 1 μm or more and 200 μm or less.

[10] The method for treating a workpiece according to any one of [1] to [8], wherein the thickness of the workpiece (C) is at least temporarily 1 μm or more and 200 μm or less.

[11] A method for manufacturing an electronic device, comprising a step of carrying out the method for treating a workpiece according to any one of [1] to

[10] .

[12] The method for manufacturing an electronic device according to

[11] , wherein the electronic device has a structure in which semiconductor chips are stacked.

[13] A laminate (D) in which a support (A), a temporary fixing material (B), and a work (C) located on the opposite side of the temporary fixing material (B) from the support (A), A laminate in which the ratio of the 10° peel strength P1 between the support (A) and the temporary fixing material (B) to the 10° peel strength P2 between the temporary fixing material (B) and the workpiece (C), P2 / P1, measured while maintaining the angle between the peeled layers at 10°, is 1.1 or more. [Effects of the Invention]

[0007] According to the workpiece processing method of the present invention, the handleability of thin or fragile workpieces such as wafers is improved, and workpieces such as wafers can be stably processed in a wide range of processing processes. In addition, unintended peeling at the interface is effectively suppressed, and processed workpieces such as wafers can be stably separated and removed using a relatively simple and low-cost process such as mechanical peeling. This makes it possible to perform multiple and / or diverse processes on workpieces such as wafers with high productivity and yield without damaging electronic components such as functional layers formed on the workpieces such as wafers, greatly contributing to improving the productivity of electronic components such as electronic devices. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic diagram illustrating mechanical peeling in one embodiment of the present invention. [Figure 2]1A and 1B are schematic diagrams illustrating separation of a support (A) from a laminate (D) in one embodiment of the present invention, where (a) shows a preferred separation form, and (b) and (c) show unpreferred separation forms. [Figure 3] 1A and 1B are schematic diagrams illustrating a method for measuring 10° peel strength specified in the present invention, in which (a) shows a case where measurement is performed using a sample for measuring 10° peel strength P1 in which a pressure-sensitive adhesive layer (B1) on the side that contacts the support (A) is laminated onto a base film (B0), (b) shows a case where measurement is performed using a sample for measuring 10° peel strength P2 in which a pressure-sensitive adhesive layer (B2) on the side that contacts the workpiece (C) is laminated onto a base film (B0), (c) shows a case where a measurement sample is prepared by laminating a polyimide film onto a temporary bonding material (B) that does not have a base film (B0) and the 10° peel strength P1 is measured, and (d) shows a case where a measurement sample is prepared by laminating a polyimide film onto a temporary bonding material (B) that does not have a base film (B0) and the 10° peel strength P2 is measured. [Figure 4] FIG. 2 is a schematic diagram showing a method for evaluating the removability of a temporary bonding material (B) from a workpiece (C) in one embodiment of the present invention. [Figure 5] FIG. 2 is a schematic diagram showing a laminate (D) according to one embodiment of the present invention. [Figure 6] FIG. 2 is a schematic view showing a laminate (D) according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention provides A step (1) of stacking a support (A), a temporary bonding material (B), and a work (C) located on the side of the temporary bonding material (B) opposite to the support (A); A step (2) of subjecting the workpiece (C) to at least one treatment selected from heat treatment, mechanical processing, wet processing, and laser processing; A step (3) of separating the work (C) from the laminate (D) having the treated work (C); A method for processing a workpiece, comprising: a method for treating a workpiece, wherein the ratio of the 10° peel strength P1 between the support (A) and the temporary fixing material (B) to the 10° peel strength P2 between the temporary fixing material (B) and the workpiece (C), P2 / P1, measured while maintaining the angle between the peeled layers at 10°, is 1.1 or more; is. That is, in the processing method of the present invention, a support (A) and a temporary bonding material (B) are used to process a workpiece (C).

[0010] Support (A) The support (A) preferably has sufficient strength and rigidity and excellent heat resistance and chemical resistance. By using such a support (A), the workpiece (C) can be stably handled even after thin grinding, and can be subjected to multiple and / or diverse processes without bending or the like. For example, the workpiece (C) on which an electronic circuit is formed can be subjected to various processes required for manufacturing an electronic device having a structure in which semiconductor chips are stacked, such as TSV connection. Materials preferably used for the support (A) include silicon, sapphire, quartz, metals (e.g., aluminum, copper, steel), and various glasses and ceramics. The support (A) may be composed of a single material, or may be composed of multiple materials, or may contain other materials deposited on the substrate. For example, the support (A) may have a vapor-deposited layer of silicon nitride or the like on a silicon wafer. In order to adjust the 10° peel strength P1 between the temporary fixing material (B), the surface may be treated by providing a silicone layer or the like.

[0011] Depending on the temperature of the process in which the laminate (D) is subjected, the support (A) may be made of plastic. For example, a sheet made of a plastic such as polyimide, acrylic, polyolefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), nylon, or urethane can be preferably used as the support (A). It is particularly preferable to use polyimide because it has a certain degree of heat resistance.

[0012] It is desirable that the thickness of the support (A) be uniform in order to obtain uniformity in the thickness of the work (C) after grinding, etc. For example, in order to thin a silicon wafer as the work (C) to 50 μm or less and keep the uniformity within ±10%, the variation in the thickness of the support (A) should be kept within ±2 μm. The thickness of the support (A) is not particularly limited, but is preferably 300 μm or more, and more preferably 500 μm or more, from the viewpoint of effectively preventing the work (C) from curving, and is preferably 1500 μm or less, and more preferably 1000 μm or less, from the viewpoint of reducing the total weight during handling or the stress required for mechanical peeling.

[0013] Temporary fixing material (B) The temporary fixing material (B) is used to fix the workpiece (C) to the support (A). It is preferable that the temporary fixing material (B) can be easily peeled off from the support (A) and the work (C). Therefore, it is preferable that the temporary fixing material (B) has sufficient adhesive strength to fix the work (C) to the support (A) but has sufficiently low adhesive strength so that it can be peeled off.

[0014] It is preferable to use a pressure-sensitive adhesive material for the temporary fixing material (B), and examples of pressure-sensitive adhesive materials used in such an embodiment include rubber-based, acrylic-based, epoxy-based, urethane-based, allyl-based, silicone-based, fluorine-based, polyimide-based pressure-sensitive adhesive materials, etc. Among these, acrylic-based or silicone-based pressure-sensitive adhesive materials are preferred because they are heat-resistant and allow easy adjustment of the adhesive strength and adhesion.

[0015] The adhesive material may be a curable adhesive material or a non-curable adhesive material, but is preferably a curable adhesive material because curing it before heat treatment makes it less likely that voids will be generated during heat treatment in the manufacturing process, suppresses adhesion buildup due to high temperatures during heat treatment, and allows for easy peeling without leaving any adhesive residue.

[0016] Examples of the curable adhesive material include a photocurable adhesive material that is crosslinked and cured by irradiation with light, and a thermosetting adhesive material that is crosslinked and cured by heating. Examples of the photocurable adhesive material and thermosetting adhesive material include photocurable adhesive material and thermosetting adhesive material that contain a monomer, oligomer or polymer such as acrylic, epoxy, urethane acrylate, epoxy acrylate, silicone acrylate or polyester acrylate as a curing component and contain a photopolymerization initiator or a thermopolymerization initiator.

[0017]

[0033] Among the above, the acrylic pressure-sensitive adhesive polymer can be obtained, for example, by synthesizing in advance a (meth)acrylic polymer having a functional group in the molecule (hereinafter referred to as functional group-containing (meth)acrylic polymer), and reacting it with a compound having in the molecule a functional group reactive with the functional group and a radically polymerizable unsaturated bond (hereinafter referred to as functional group-containing unsaturated compound).

[0018] The functional group-containing (meth)acrylic polymer is obtained by copolymerizing, in a conventional manner, an alkyl acrylate and / or alkyl methacrylate ester, whose alkyl group typically has 2 to 18 carbon atoms, with a functional group-containing monomer and, if necessary, with other modifying monomers copolymerizable therewith. The weight-average molecular weight of the functional group-containing (meth)acrylic polymer is typically about 200,000 to 2,000,000.

[0019] Examples of the functional group-containing monomer include carboxyl group-containing monomers such as acrylic acid and methacrylic acid, hydroxyl group-containing monomers such as hydroxyethyl acrylate and hydroxyethyl methacrylate, epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate, isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate, and amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate.

[0020] Examples of the other copolymerizable modifying monomers include various monomers used in general (meth)acrylic polymers, such as vinyl acetate, acrylonitrile, and styrene.

[0021] The functional group-containing unsaturated compound to be reacted with the functional group-containing (meth)acrylic polymer can be the same as the functional group-containing monomer described above, depending on the functional group of the functional group-containing (meth)acrylic polymer. For example, if the functional group of the functional group-containing (meth)acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used. If the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. If the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide is used. If the functional group is an amino group, an epoxy group-containing monomer is used.

[0022] Examples of the photopolymerization initiator include those activated by irradiation with light having a wavelength of 250 to 800 nm. Examples of such photopolymerization initiators include acetophenone derivative compounds such as methoxyacetophenone, benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether, ketal derivative compounds such as benzyl dimethyl ketal and acetophenone diethyl ketal, phosphine oxide derivative compounds, bis(η5-cyclopentadienyl)titanocene derivative compounds, benzophenone, Michler's ketone, chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenyl ketone, and 2-hydroxymethylphenylpropane. These photopolymerization initiators may be used alone or in combination of two or more.

[0023] Examples of the thermal polymerization initiator include those that decompose by heat and generate active radicals that initiate polymerization and curing. Specific examples include t-butylperoxy-2-ethyl hexanoate, bis(4-methylbenzoyl) peroxide, benzoyl peroxide, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(4,4-bis-(t-butylperoxy)cyclohexyl)propane, t-hexylperoxyisopropyl monocarboxylate, t-butylperoxyacetate, 2,2-bis-( t-butylperoxy)butane, 4,4-bis-(t-butylperoxy)n-butyl pentanoate, bis-t-hexyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, bis(2-t-butylperoxyisopropyl)benzene, t-butylcumyl peroxide, di-t-butyl peroxide 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne, diisopropylbenzene hydroperoxide, and the like. Among these thermal polymerization initiators, commercially available ones are not particularly limited, but suitable examples include Perbutyl O, Niper BMT, Niper BW, Perhexa HC, Perhexa C, Pertetra A, Perhexyl I, Perbutyl A, Perhexa 22, Perhexa V, Perhexyl D, Percumyl D, Perhexa 25B, Perbutyl P, Perbutyl C, Perhexyne 25B, Percumyl P (all manufactured by NOF Corporation), Perkadox 12XL25 (manufactured by Nouryon Chemical Co., Ltd.), etc. These thermal polymerization initiators may be used alone or in combination of two or more.

[0024] The oligomer or monomer used as the curing component generally has a molecular weight of 10,000 or less and has a number of radically polymerizable unsaturated bonds in the molecule of 1 to 40. From the viewpoint of three-dimensional reticulation, the number of radically polymerizable unsaturated bonds is preferably 2 or more.

[0025] Examples of the oligomer or monomer as the curing component include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, and the same methacrylates as above. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylates, urethane acrylates, and the same methacrylates as above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

[0026] The temporary fixing material (B) may contain, as desired, an acrylic polymer having no unsaturated double bond, various thermal crosslinking agents such as an isocyanate compound, a melamine compound, or an epoxy compound, or known additives such as a mold release agent, a plasticizer, a resin, a surfactant, a wax, or a particulate filler.

[0027] In the temporary bonding material (B), it is preferable to use a release agent from the viewpoint of adjusting the peel strength between the temporary bonding material (B) and the support (A) and / or the work (C). The release agent is not particularly limited as long as it generally exhibits a release effect. Examples include hydrocarbon compounds, silicone compounds, fluorine compounds, and polyethylene waxes, carnauba wax, montanic acid, stearic acid, and the like, which are known as release agents for plastic materials. Among these, silicone and fluorine compounds are preferred, and silicone and fluorine compounds having a functional group capable of crosslinking with the curable adhesive are more preferred. Silicone compounds, in particular, have excellent heat resistance, preventing scorching of the adhesive even after treatment involving heating at 200°C or higher, and bleed out to the adherend interface during peeling, facilitating peeling. Since the silicone compound has a functional group that can crosslink with the curable adhesive, it chemically reacts with the curable adhesive upon light irradiation or heating and is incorporated into the curable adhesive, preventing the silicone compound from adhering to the adherend and causing contamination. Furthermore, the incorporation of a silicone compound also has the effect of preventing adhesive residue on semiconductor chips. Other examples of the release agent include plasticizers. The plasticizer is not particularly limited as long as it generally reduces the adhesive strength of the adhesive material to the adherend. Examples of the plasticizer include trimellitic acid esters, pyromellitic acid esters, phthalic acid esters, and adipic acid esters.

[0028] The amount of release agent added is not particularly limited, but is appropriately determined so as to obtain a release effect. On the other hand, the amount added is controlled so as not to be excessive so as not to significantly impair the adhesive function of the temporary fixing material (B). For example, it is desirable to adjust the amount added according to the peel force, usually about 0.1 to 5 parts by mass, preferably about 0.1 to 3 parts by mass, and more preferably about 0.1 to 1 part by mass, based on 100 parts by mass of the total temporary fixing material (B).

[0029] Furthermore, when a plasticizer is added, it is desirable to adjust the amount added according to the peel strength, typically about 5 to 50 parts by mass, preferably about 10 to 50 parts by mass, and more preferably about 20 to 40 parts by mass. In this embodiment, these release agents can be used alone or in combination.

[0030] The thickness of the temporary bonding material (B) is not particularly limited, but a preferred lower limit is 5 μm and a preferred upper limit is 250 μm, and a more preferred lower limit of the thickness of the temporary bonding material (B) is 10 μm and a more preferred upper limit is 200 μm. If the thickness of the temporary bonding material (B) is within this range, it can absorb the unevenness of the workpiece (C) and can be temporarily fixed to the support (A) with sufficient strength, and when peeling off the temporary bonding material (B), the peel force can be easily adjusted to a preferred range.

[0031] The temporary bonding material (B) may be a single layer or a laminate of multiple layers. In the case of a laminate of multiple layers, it is desirable that the layers on the work (C) side and the support (A) side be layers having adhesive properties (adhesive layers). In this case, one adhesive layer (B1) can be configured to have an appropriate peel strength between it and the support (A), and the other adhesive layer (B2) can be configured to have an appropriate peel strength between it and the work (C). In this case, it is preferable that the adhesive layer (B1) in contact with the support (A) and the adhesive layer (B2) in contact with the work (C) have different compositions. In this case, the adhesive layer (B1) and the adhesive layer (B2) may have a layered structure in the general sense, in which the composition changes discontinuously at their interface, or may have a so-called gradient composition, in which the composition changes continuously. The adhesive layer (B1) in contact with the support (A) and the adhesive layer (B2) in contact with the work (C) may be laminated directly, but it is preferable that they are laminated on both sides of a base film (B0) in between, forming a so-called double-sided adhesive tape. In this embodiment, the adhesive layer (B1) can be designed from the perspective of optimizing the peel strength between it and the support (A), the adhesive layer (B2) can be designed from the perspective of optimizing the peel strength between it and the work (C), and the base film (B0) can be designed from the perspective of the mechanical strength and handleability of the entire temporary bonding material (B) and the entire laminate (D), and this is particularly advantageous from the perspective of optimizing the performance of the temporary bonding material (B). An example of a laminate (D) using a temporary bonding material (B) consisting of a pressure-sensitive adhesive layer (B1), a base film (B0), and a pressure-sensitive adhesive layer (B2) is shown in Fig. 5. In the figure, 11 indicates a support (A), 20 indicates the pressure-sensitive adhesive layer (B1) on the support (A) side, 19 indicates the base film (B0), 18 indicates the pressure-sensitive adhesive layer (B2) on the work (C) side, and 13 indicates the work (C). The material of the base film (B0) is not particularly limited, but it is preferable to use a plastic film, and examples thereof include films, sheets, sheets with a mesh structure, and sheets with holes, such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, urethane, polyether ether ketone (PEEK), liquid crystal polymer (LCP), and polyimide.

[0032] Work (C) There are no particular limitations on the workpiece (C) to be processed by the method of the present invention; any workpiece that can be processed in step (2) of the present invention can be used. In particular, the method of the present invention is preferably used to process workpieces that require careful handling due to their thinness or fragility, and therefore require temporary fixing (temporary fixation). Here, the thinness and fragility of the workpiece are often caused by steps (1) and / or (2) described below. For example, the method of the present invention is preferably used to process workpieces whose thickness temporarily decreases during processing, causing handling problems. Examples of temporary thinning include cases where a thin workpiece is processed starting from a thin one, cases where a relatively thick workpiece is thinned during the process, and cases where the thinned workpiece is further processed. The thickness of the temporarily thinned workpiece (C) is typically 1 to 200 μm. For example, in a case where a semiconductor wafer on which processing of the functional layer has been completed is temporarily fixed to a carrier so that the functional layer faces the carrier, the opposite side of the functional layer (back side) is thinly ground, ions are implanted on the back side, annealing is performed, and electrodes are formed, and the semiconductor wafer in the process corresponds to the work (C). For example, in the case where a flexible film is temporarily fixed to a carrier, and then processed such as forming a circuit or mounting an electronic device on the flexible film, and then separated from the carrier, the flexible film during the process corresponds to the work (C). Alternatively, this method can be suitably applied to a process in which a group of devices such as chips, which are not necessarily thin, is temporarily fixed on a temporary fixing material (B) formed on a support (A), and then encapsulated to form a molded wafer or molded panel, which is then separated from the support. In this type of use, the work (C) corresponds to a group of devices such as chips, or a wafer or panel after encapsulation, and these are temporarily fixed because they are easily damaged. As described above, the workpiece (C) to be processed in the present invention includes a workpiece whose state changes during the process. As mentioned above, there are no particular limitations on the workpiece (C) to be processed by the present invention, but more specific examples include resin-coated copper foil, prepreg, thin multilayer circuit boards, flexible circuit boards, film substrates with organic EL or LEDs formed thereon, thin display components, lens arrays, and semiconductor wafers. For example, semiconductor wafers include silicon wafers, compound semiconductor wafers such as SiC, AlSb, AlAs, AlN, AlP, BN, BP, BAs, GaSb, GaAs, GaN, GaP, InSb, InAs, InN, or InP, quartz wafers, sapphire, glass, mold wafers, and rectangular mold panels. The silicon wafer or compound semiconductor wafer may be doped.

[0033] Alternatively, the workpiece (C) can be formed by repeatedly performing a combination of processes such as lamination, coating, sputtering, deposition, etching, chemical vapor deposition (CVD), physical vapor deposition (PVD), resist coating and patterning, reflow, plasma treatment, chip bonding, wire bonding, and resin sealing on the temporary bonding material (B) formed on the support (A). The thickness of the workpiece (C) is not particularly limited, but is typically 1 μm to 2000 μm. Examples of the workpiece (C) formed on the temporary bonding material (B) include thin multilayer circuit boards, component-embedded boards, rewiring layers, film substrates with organic EL or LEDs, mold array packages, molded wafers, and molded panels.

[0034] An electric / electronic functional layer may be formed on or in the workpiece (C). Suitable examples of the functional layer include an electronic circuit, a capacitor, a transistor, a resistor, an electrode, an optical element, a MEMS, etc., but other microdevices may also be used. The surfaces of these functional layers may have structures, typically electrodes, formed from one or more of the following materials: silicon, polysilicon, silicon dioxide, (oxy)silicon nitride, metals (e.g., copper, aluminum, gold, tungsten, tantalum), low-k dielectrics, polymer dielectrics, and various metal nitrides and metal silicides. The surface of the workpiece (C) on which the devices are formed may also have raised structures such as solder bumps and metal posts and pillars.

[0035] Process (1) The method for processing a workpiece of the present invention includes a step (1) of stacking the above-mentioned support body (A), temporary bonding material (B), and workpiece (C) located on the side of the temporary bonding material (B) opposite to the support body (A). An example of the state after step (1) is shown in Fig. 6. In the figure, 11 denotes the support (A), 12 denotes the temporary bonding material (B), and 13 denotes the workpiece (C). By fixing the workpiece (C) to the support plate (A) via the temporary fixing material (B), the workpiece (C) can be easily handled when being processed in the subsequent step (2), and bending or breakage can be prevented.

[0036] The order in which the support (A), temporary bonding material (B), and work (C) are laminated is not particularly limited, and these layers may be laminated at once or sequentially. Lamination also includes forming the work (C) on the temporary bonding material (B) as described above. When the temporary fixing material (B) is supplied as a liquid curable adhesive or the like, the liquid curable adhesive or the like can be applied to either the work (C) or the support (A), or both, by spin coating or the like to form the temporary fixing material (B) or a precursor of the temporary fixing material (B), and then a laminate can be created. When the temporary bonding material (B) or the precursor of the temporary bonding material (B) is supplied as a solid film, the adhesive strength to the support is usually set lower than that to the work side. Therefore, in order to prevent peeling during handling, it is preferable to first attach the film to the work (C) and then laminate the support (A) on top of it. Furthermore, when the film is attached at normal pressure and only the formation of the laminate is carried out under reduced pressure, it is preferable to first attach the film-like temporary bonding material to the support (A) and then attach this to the work (C) in order to improve the absorption of unevenness in the work such as a wafer.

[0037] When the temporary fixing material (B) or a precursor of the temporary fixing material (B) contains a curable adhesive component, the temporary fixing material (B) may be obtained by irradiating the curable adhesive component with light or heating it in step (1) to crosslink and cure the curable adhesive component. The curable adhesive component that has been crosslinked and cured by irradiation with light or heat has dramatically improved chemical resistance, and can prevent the adhesive from dissolving in a chemical solution, even when a chemical solution treatment is applied to the surface of the workpiece (C) that is not in contact with the temporary bonding material (B) in step (2). Furthermore, the crosslinked and cured curable adhesive component has an increased elastic modulus, and therefore is less likely to develop adhesion even at high temperatures, making it relatively easy to peel. In this embodiment, even though the workpiece (C) is subjected to heat treatment, machining treatment, and / or wet treatment in step (2), sufficient adhesive strength is maintained during the workpiece (C) treatment, and after the workpiece (C) treatment step is completed, the workpiece (C) can be peeled off from the temporary fixing material (B) in step (3) without being damaged or leaving any adhesive residue.

[0038] For example, when a photocurable adhesive component that crosslinks and cures upon irradiation with light is used, the adhesive component contains a polymer having an unsaturated double bond, such as a vinyl group, in its side chain and a photopolymerization initiator that is activated at a wavelength of 250 to 800 nm. Irradiation of the photocurable adhesive component is preferably at an illuminance of 5 mW or more, more preferably at an illuminance of 10 mW or more, even more preferably at an illuminance of 20 mW or more, and particularly preferably at an illuminance of 50 mW or more. Furthermore, irradiation is preferably at an integrated illuminance of 300 mJ or more, more preferably at an integrated illuminance of 500 mJ to 10,000 mJ, even more preferably at an integrated illuminance of 500 mJ to 7,500 mJ, and particularly preferably at an integrated illuminance of 1,000 mJ to 5,000 mJ.

[0039] Furthermore, for example, when a pressure-sensitive adhesive containing a polymer having an unsaturated double bond such as a vinyl group in a side chain and a thermal polymerization initiator that is activated by heating at about 50 to 200°C is used as the thermosetting pressure-sensitive adhesive component in which the temporary fixing material (B) or a precursor of the temporary fixing material (B) is crosslinked and cured by heating, the thermosetting pressure-sensitive adhesive component can be crosslinked and cured by heating at a temperature of about 50 to 200°C for 10 to 60 minutes.

[0040] When the precursor of the temporary bonding material (B) is cured to form the temporary bonding material (B) as described above, the material may be laminated with the support (A) or the workpiece (C) after curing, or may be cured after lamination, or may be laminated in a semi-cured state and then finally cured.

[0041] Process (2) The method for treating a workpiece of the present invention then includes step (2) of subjecting the workpiece (C) after step (1) to at least one treatment selected from heat treatment, mechanical processing, wet processing, and laser processing. The above step (2) also includes TSV processing and processing necessary for forming a structure in which TSV-processed semiconductor chips are stacked. Examples of the heat treatment (including treatment accompanied by heat generation; the same applies hereinafter) include, but are not limited to, sputtering, vapor deposition, etching, chemical vapor deposition (CVD), physical vapor deposition (PVD), resist coating / patterning, heat lamination of a resin composition film, heat curing of a resin composition, heat drying of a resin composition, baking of a resin composition, reflow, resin sealing, plasma treatment, chip bonding, wire bonding, flip-chip bonding, and surface activated direct bonding. The workpiece treatment method of the present invention can be suitably adapted to temperatures of 100°C, particularly 150°C or higher, during the above-mentioned steps.

[0042] The machining process is typically a polishing, grinding, drilling, or cutting process of the wafer, but is not limited to these and also includes singulation and the like. When grinding or polishing a workpiece (C) having an electrode formed on its surface, the surface on which the electrode is not formed (back surface) is ground or polished. The thickness of the workpiece (C) after back surface grinding and polishing varies depending on the electronic device in which the resulting electronic device will be used, but is usually set to 1 μm or more and 200 μm or less, preferably 5 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less. This allows the resulting electronic device to be made thinner, thereby realizing the miniaturization of electronic devices that use such electronic devices.

[0043] In this embodiment, when grinding and polishing the workpiece (C), the workpiece (C) is stacked on a rigid support (A) via a temporary fixing material (B), which allows the workpiece (C) to be ground with better processing accuracy, and after this grinding, the workpiece (C) can be subjected to further processing steps or easily separated from the support (A) and the temporary fixing material (B) without damaging the workpiece (C).

[0044] The wet processing is a coating process such as spin coating, inkjet printing, or screen printing; a polishing process such as CMP; or a process using an acid, alkali, or organic solvent; examples of the wet processing include plating processes such as electrolytic plating and electroless plating; wet etching processes using hydrofluoric acid, an aqueous solution of tetramethylammonium hydroxide (TMAH), or the like; resist stripping processes using N-methyl-2-pyrrolidone, monoethanolamine, DMSO, or the like; and cleaning processes using concentrated sulfuric acid, aqueous ammonia, aqueous hydrogen peroxide, or the like, but are not limited to these. The laser treatment includes, but is not limited to, annealing, via processing, circuit formation processing by direct writing, and pre-treatment for separation from the support.

[0045] In the method for processing a workpiece of the present invention, a dicing tape may be applied to the processed surface of the workpiece, such as a wafer, after the above processing, prior to the step (3) described below. By applying the dicing tape in advance, dicing can be performed quickly after peeling off the support (A) and the temporary bonding material (B) in the step (3).

[0046] In the present invention, the support (A) is separated from the temporary bonding material (B) in step (3), but a pre-peeling treatment may be carried out in step (2). Specifically, methods such as laser treatment, swelling or dissolution of the temporary bonding material (B) with a solvent, etc. can be appropriately adopted before mechanical peeling, but it is preferable not to perform these treatments because it is cost-effective since the equipment can be simplified. In this specification, the laminate having the workpiece (C) that has been subjected to step (2) is also referred to as laminate (D).

[0047] Process (3) The method for treating a workpiece of the present invention then includes a step (3) of separating the treated workpiece (C) from the stack (D). Separation of the workpiece (C) from the laminate (D) is preferably achieved by separating the support (A) from the laminate (D) and then removing the temporary bonding material (B) remaining on the workpiece (C). In this embodiment, when removing the temporary bonding material (B) remaining on the workpiece (C), the normally rigid support (A) has already been separated from the laminate (D), so the workpiece (C) can be separated from the temporary bonding material (B) without applying excessive stress to the workpiece (C), thereby minimizing the risk of damaging functional layers and the like formed on the workpiece (C). There are no particular limitations on the method for separating the support (A) from the temporary bonding material (B), but it is preferable to use mechanical peeling. Both the separation between the support (A) and the temporary bonding material (B) and the separation between the temporary bonding material (B) and the workpiece (C) may be performed by mechanical peeling, or a method other than mechanical peeling may be used for one of them.

[0048] In the method for treating a workpiece of the present invention, since the peel strength ratio P2 / P1 is 1.1 or more, peeling between the support (A) and the temporary bonding material (B) is relatively easy, and therefore the support (A) can be stably peeled from the laminate (D) over the entire surface of the laminate (D) by a relatively simple process such as mechanical peeling. In this case, peeling at an unintended interface, i.e., between the temporary bonding material (B) and the workpiece (C), is effectively suppressed, thereby limiting the risk of damaging the functional layer formed on the workpiece (C), etc.

[0049] In the laminate (D) composed of the support (A), the temporary bonding material (B), and the workpiece (C) separated in step (3), the ratio of the 10° peel strength P1 between the support (A) and the temporary bonding material (B) to the 10° peel strength P2 between the temporary bonding material (B) and the workpiece (C), P2 / P1, measured while maintaining the angle between the peeled layers at 10°, is 1.1 or greater. The 10° peel strength P1 between the support (A) and the temporary bonding material (B) and the 10° peel strength P2 between the temporary bonding material (B) and the workpiece (C) are measured after a thermal history equivalent to that in step (2), described below. For example, if a thermal history of 150 to 200°C is applied in step (2), the values ​​are those after the thermal history. According to the workpiece processing method of the present invention, since the peel strength ratio P2 / P1 is 1.1 or more, the support (A) can be stably peeled from the temporary bonding material (B) and over the entire surface of the laminate (D) by a relatively simple process such as mechanical peeling. In this case, peeling at the unintended interface, i.e., between the temporary bonding material (B) and the workpiece (C), is effectively suppressed, thereby limiting the risk of damaging the functional layer formed on the workpiece (C). In addition, the phenomenon of some of the temporary fastening material (B) remaining on the support (A) or some of the temporary fastening material (B) on the workpiece (C) being missing is effectively suppressed, so the risk of uneven stress being applied to the workpiece (C) or support (A) and causing them to break is also limited.

[0050] The 10° peel strength P1 between the support (A) and the temporary bonding material (B) and the 10° peel strength P2 between the temporary bonding material (B) and the work (C) are the force (N / mm) per width of the peeled portion required to proceed with peeling while maintaining the angle between the peeled layers (support (A) and the temporary bonding material (B), or the temporary bonding material (B) and the work (C)) at 10°. That is, the 10° peel strength P1 between support (A) and temporary bonding material (B) and the 10° peel strength P2 between temporary bonding material (B) and work (C) can be determined by measuring the force required for peeling between support (A) and temporary bonding material (B) or between temporary bonding material (B) and work (C) in the state shown in FIG. 3 or a state similar thereto, measuring the force required for peeling, and dividing this by the width of the peeled portion. More specifically, they can be measured by the following method.

[0051] The support (A) and workpiece (C) are usually rigid or brittle, and it is usually difficult to maintain a 10° angle between the peeled layers in the laminate (D) consisting of support (A), temporary bonding material (B), and workpiece (C). Therefore, when measuring the 10° peel strength P1 between support (A) and temporary bonding material (B), a 10° peel strength P1 measurement sample without workpiece (C) can be used (Figures 3(a) and (c)). When measuring the 10° peel strength P2 between temporary bonding material (B) and workpiece (C), a 10° peel strength P2 measurement sample without support (A) can be used (Figures 3(b) and (d)). In the former case, when the temporary fixing material (B) has a base film (B0), a sample for measuring 10° peel strength P1 is constructed from the support (A) and the temporary fixing material (B) having the base film (B0), and measurement is performed (FIG. 3(a)). When the temporary fixing material (B) does not have a base film and consists only of an adhesive layer, a polyimide film or the like is backed on the adhesive layer to construct a sample for measuring 10° peel strength P1, and measurement is performed (FIG. 3(c)). In the latter case, when the temporary bonding material (B) has a base film (B0), a sample for measuring the 10° peel strength P2 is constructed from the temporary bonding material (B) having the base film (B0) and the workpiece (C), and the measurement is performed (Fig. 3(b)). When the temporary bonding material (B) does not have a base film and consists only of an adhesive layer, a polyimide film or the like is backed on the adhesive layer to construct a sample for measuring the 10° peel strength P2, and the measurement is performed (Fig. 3(d)).

[0052] The peel strength ratio P2 / P1 is preferably 1.1 or more, and particularly preferably 1.3 or more. There is no particular upper limit to the peel strength ratio P2 / P1, but from the viewpoint of properly peeling the workpiece (C) from the temporary bonding material (B), it is desirable that the peel strength P2 between the temporary bonding material (B) and the workpiece (C) is not excessively large, and from the viewpoint of stably carrying out the processing in step (2), particularly the machining processing, it is desirable that the 10° peel strength P1 between the support body (A) and the temporary bonding material (B) is not too small. Therefore, the peel strength ratio P2 / P1 is preferably 30 or less, more preferably 15 or less, and particularly preferably 7 or less.

[0053] In step (3), from the viewpoint of stably peeling the support (A) from the temporary bonding material (B) over the entire surface of the laminate (D) using a relatively simple process such as mechanical peeling without applying excessive stress to the workpiece (C), it is preferable that the 10° peel strength P1 between the support (A) and the temporary bonding material (B) be 10 N / 25 mm or less. The 10° peel strength P1 between the support (A) and the temporary fixing material (B) is more preferably 8 N / 25 mm or less, and particularly preferably 7 N / 25 mm or less. From the viewpoint of stably carrying out the processing in step (2), particularly the machining processing, the 10° peel strength P1 between the support (A) and the temporary fixing material (B) is preferably 1 N / 25 mm or more, and more preferably 2 N / 25 mm or more.

[0054] The separation of the temporary bonding material (B) and the work (C) in step (3) is preferably achieved by separating the support (A) from the laminate (D) and then removing the temporary bonding material (B) remaining on the work (C). From this perspective, the 10° peel strength P2 between the temporary bonding material (B) and the work (C) is preferably 30 N / 25 mm or less, and more preferably 20 N / 25 mm or less. From the viewpoint of stably carrying out the processing in step (2), particularly the machining processing, the 10° peel strength P2 between the temporary fixing material (B) and the work (C) is preferably 2 N / 25 mm or more, and more preferably 3 N / 25 mm or more.

[0055] There are no particular limitations on the means for adjusting the 10° peel strength P1, 10° peel strength P2, and peel strength ratio P2 / P1, but they can be increased or decreased as appropriate by, for example, means conventionally used in the art. More specifically, they can be increased or decreased as appropriate by adjusting the composition and manufacturing process of each layer, the manufacturing process of the laminate (D), etc. For example, the 10° peel strength P1 and the 10° peel strength P2 can be increased by increasing the amount of adhesive component such as an adhesive or pressure-sensitive adhesive used in the temporary fixing material (B), and the 10° peel strength P1 and the 10° peel strength P2 can be decreased by adding a release agent to the temporary fixing material (B).

[0056] The mechanical peeling method in this embodiment is not particularly limited, and peeling can be performed using a commercially available device, etc. For example, peeling is preferably performed by the method shown in FIG. In this method, the workpiece (C) side 13 of the laminate (D) is fixed onto a chuck table (not shown) via dicing tape 14, and then the support (A) 11 is held by a holding mechanism (not shown). The remover 16 is slid into the interface between the support 11 (A) and the temporary fixing material 12 (B), and an upward force is applied to the end of the support 11 (A), forming a peeling interface between the support 11 (A) and the temporary fixing material 12 (B) that triggers peeling (Figure 1(b)). The support (A) 11 is warped by applying pressure using the holding mechanism, expanding the peeling interface and promoting peeling (Fig. 1(c)). When the peeling interface spreads and a peeling interface is formed over the entire surface between the support (A) 11 and the temporary fixing material (B) 12, the support (A) 11 is peeled off from the temporary fixing material (B) 12. Examples of commercially available devices of this type include XBC Gen2 manufactured by SUSS, EVG805 manufactured by EVG, and TWH-SR series manufactured by Tatsumo Corporation.

[0057] At this time, according to the present invention, peeling at the interface between 12 temporary fixing material (B) and 13 workpiece (C), which is not intended to peel at this stage, is effectively suppressed, so that the functional layers etc. formed on 13 workpiece (C) are effectively protected by 12 temporary fixing material (B), and the risk of damage to these functional layers etc. can be limited (Figure 2(a)).

[0058] In the prior art, before the separation between the support 11 (A) and the temporary bonding material 12 (B), separation could occur at the interface between the temporary bonding material 12 (B) and the workpiece 13 (C), which is not intended to be separated at this stage (FIG. 2(b)). As a result, there was a risk that the electronic circuits formed on the workpiece 13 (C) would be damaged during the separation or in subsequent processes that still required protection by the temporary bonding material 12 (B). Furthermore, in the conventional technology, there were cases where the support (A) could not be completely peeled off because some of the temporary bonding material (B) 12 remained on the support (A) 11 or some of the temporary bonding material (B) on the workpiece (C) 13 was missing (Fig. 2(c)). As a result, uneven stress was applied to the workpiece (C) 13 and the support (A) 11, which could cause them to break. When the temporary bonding material (B) remains on the workpiece (C), it may be removed by dissolving it in a solvent. The present invention solves these problems of the prior art, prevents unintended interfacial peeling and uneven peeling, or at least significantly reduces the frequency of these occurrences, thereby making it possible to perform multiple and / or diverse processes on workpieces such as wafers with high productivity and yield without damaging the functional layers formed on the workpieces.

[0059] The workpiece, such as a wafer, processed by the workpiece processing method of the present invention can be subjected to further processes to manufacture a final product. If a functional layer is formed on the workpiece, further processes typically used in the manufacture of electronic devices, such as semiconductor devices, such as dicing, bonding, packaging, and sealing can be carried out to manufacture the final product. [Example]

[0060] The present invention will be specifically described below, but the present invention is not limited in any way by the following examples.

[0061] The physical properties and characteristics in the examples and comparative examples were evaluated by the following methods. (1) Mechanical peelability After applying the prescribed thermal history shown in Table 1 to the prepared laminate (D), it was fixed at room temperature with the workpiece (C) side facing down on a dicing tape affixed to a ring frame (15), and the dicing tape was fixed by vacuum chucking (Fig. 1(a)). In order to peel the interface between the support (A) and the temporary bonding material (B), as shown in Fig. 1, a remover (16) was slid into the interface between the support (A) and the temporary bonding material (B), and an upward force of typically 120 N was applied to the edge of the support (A), forming a peel interface that triggered peeling between the support (A) and the temporary bonding material (B) (Fig. 1(b)). Next, pressure was applied to the formed peel interface to expand the peel interface, thereby peeling off the support (A) 11 (Figure 1(c)). The peelability was evaluated according to the following criteria. ○: The entire surface of the intended support (A) / temporary bonding material (B) interface was peeled off, and no damage occurred to the workpiece (C). ×: Peeling occurred unintentionally at the interface between the temporary bonding material (B) and the workpiece (C).

[0062] (2) Removability of temporary fixing material (B) from workpiece (C) After the mechanical peelability evaluation described above, the 13 workpiece (C) / 12 temporary bonding material (B) laminate was fixed to the 14 dicing tape attached to the 15 ring frame, and the 17 adhesive tape was attached to the entire surface of the 12 temporary bonding material (B). The 14 dicing tape was fixed with a vacuum chuck, and the 12 temporary bonding material (B) was peeled off at a peel angle of 90° and a peel speed of 5 mm / s. The peelability was evaluated according to the following criteria. ◯: The temporary bonding material (B) was completely peeled off from the workpiece (C), and no damage occurred to the workpiece (C). ×: The temporary bonding material (B) could not be peeled off from the workpiece (C).

[0063] (3) 10° peel strength P1 (peel strength between support and temporary adhesive) (3-1) When using a base film (B0) as a temporary bonding material A sample for measuring P1 was prepared by laminating a pressure-sensitive adhesive layer (B1) on the side of the substrate film (B0) 19 that contacts the support (A) 20. (3-2) When the base film (B0) is not used as the temporary bonding material A polyimide film 21 (double-sided plasma treatment, thickness 38 μm, manufactured by Toray DuPont Co., Ltd., product name: Kapton (registered trademark) 150EN-A) was prepared, and a sample for P1 measurement was prepared by laminating the same material as the temporary bonding material 12 on top of this. (3-3) Measurement The P1 measurement sample prepared in (3-1) or (3-2) above was cut to a size of 2.5 cm x 5 cm, and the surface of the P1 measurement sample, the same material as the adhesive layer (B1) or the temporary bonding material (12), was attached to the attachment surface of the support (A) cut to a size of 3 cm x 6 cm, using a 2 kg roller back and forth once. The prepared support (A) / P1 measurement sample laminate was then heated at 140°C for 30 minutes, which simulates the pretreatment conditions in step (1) of each example and comparative example. The sample was then subjected to the specified thermal history shown in Table 1, which simulates the conditions for step (2), and then left to cool for one week at 22.5±1°C and a relative humidity of 50±10%. The peel strength P1 was then measured at this temperature and humidity using a VPA-S (manufactured by Kyowa Interface Science Co., Ltd.) at a pulling rate of 300 mm / min and a peel angle of 10° (Figure 3(a) or (c)).

[0064] (4) 10° peel strength P2 (peel strength between temporary adhesive material and workpiece) (4-1) When using a base film (B0) as a temporary bonding material A sample for measuring P2 was prepared by laminating a pressure-sensitive adhesive layer (B2) on the side that contacts the workpiece (C) on the substrate film (B0). (4-2) When the base film (B0) is not used as the temporary bonding material A polyimide film 21 (double-sided plasma treatment, thickness 38 μm, manufactured by Toray DuPont Co., Ltd., product name: Kapton (registered trademark) 150EN-A) was prepared, and a sample for P2 measurement was created by laminating the same material as the temporary bonding material 12 on top of this. (4-3) Measurement The P2 measurement sample prepared in (4-1) or (4-2) above was cut to a size of 2.5 cm x 5 cm, and the surface of the P2 measurement sample, the same material as the adhesive layer (B2) or the temporary bonding material (12), was attached to the attachment surface of the workpiece (C), which had been cut to a size of 3 cm x 6 cm, using a 2 kg roller back and forth. The prepared workpiece (C) / P2 measurement sample laminate was then heated at 140 °C for 30 minutes, a condition simulating the pretreatment in step (1) in each example and comparative example. The sample was then subjected to the specified thermal history shown in Table 1, a condition simulating step (2), and then left to cool for one week at 22.5 ± 1 °C and a relative humidity of 50 ± 10%. The peel strength P2 was then measured at this temperature and humidity using a VPA-S (manufactured by Kyowa Interface Science Co., Ltd.) at a pulling rate of 300 mm / min and a peel angle of 10° (Figure 3(b) or (d)).

[0065] Details of the materials and ingredients used in the examples and comparative examples are as follows. Support (A) and workpiece (C) The following glass or Si was used as either the support (A) or the workpiece (C): Glass A support substrate for silicon back grinding made of borosilicate heat-resistant glass with an outer diameter of 300 or 200 mm and a thickness of 700 μm was used. ·Si A Si mirror wafer with an outer diameter of 300 or 200 mm and a thickness of 750 μm was used.

[0066] Resin for forming temporary fixing material (B) (Meth)acrylic resin solution N: 49 parts by mass of ethyl acrylate, 20 parts by mass of 2-ethylhexyl acrylate, 21 parts by mass of methyl acrylate, 10 parts by mass of glycidyl methacrylate, and 0.5 parts by mass of a benzoyl peroxide polymerization initiator were reacted in a solvent consisting of 65 parts by mass of toluene and 50 parts by mass of ethyl acetate at 80°C for 10 hours. After the reaction was completed, the resulting solution was cooled, and 25 parts by mass of xylene, 5 parts by mass of acrylic acid, and 0.5 parts by mass of tetradecyldimethylbenzylammonium chloride were added to the cooled solution. The mixture was reacted at 85°C for 32 hours while blowing air into it, yielding (meth)acrylic resin solution N. Silicone-modified (meth)acrylic resin solution NS To 270 parts by mass of the above-mentioned (meth)acrylic resin solution N, 0.3 parts by mass of carboxy-modified organopolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., product name: X-22-3710) was added, and the mixture was reacted at 60°C for 7 days to obtain a silicone-modified (meth)acrylic resin solution NS. (Meth)acrylic resin solution L A (meth)acrylic adhesive (Bindceram SA591, manufactured by Mitsui Chemicals, Inc.) was used. (Meth)acrylic resin emulsion H Using 0.5 parts by weight of ammonium persulfate as a polymerization initiator, 63 parts by weight of 2-ethylhexyl acrylate, 21 parts by weight of n-butyl acrylate, 9 parts by weight of methyl methacrylate, 3 parts by weight of 2-hydroxyethyl methacrylate, 2 parts by weight of methacrylic acid, 1 part by weight of acrylamide, 1 part by weight of polytetramethylene glycol diacrylate (manufactured by NOF Corporation, product name: ADT-250), and 2 parts by weight of an aqueous solution of polyoxyethylene nonylpropenylphenyl ether ammonium sulfate (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name: Aqualon HS-1025) were emulsion polymerized in deionized water at 70°C. After polymerization was completed, the pH was adjusted to 7.0 using aqueous ammonia to obtain (meth)acrylic resin emulsion H with a solids content of 56.5% by weight. (Meth)acrylic resin emulsion B Using 0.5 parts by mass of 4,4'-azobis-4-cyanovaleric acid (manufactured by Otsuka Chemical Co., Ltd., trade name: ACVA) as a polymerization initiator, 74 parts by mass of n-butyl acrylate, 14 parts by mass of methyl methacrylate, 9 parts by mass of 2-hydroxyethyl methacrylate, 2 parts by mass of methacrylic acid, 1 part by mass of acrylamide, and 3 parts by mass of HS-1025 were emulsion polymerized in deionized water at 70°C. After completion of polymerization, the pH was adjusted to 7.0 using aqueous ammonia, yielding (meth)acrylic resin emulsion B with a solids content of 42.5% by mass. (Meth)acrylic resin emulsion A Using 0.65 parts by mass of ACVA as a polymerization initiator, 63 parts by mass of 2-ethylhexyl acrylate, 18 parts by mass of n-butyl acrylate, 12 parts by mass of methyl methacrylate, 3 parts by mass of 2-hydroxyethyl methacrylate, 2 parts by mass of methacrylic acid, 1 part by mass of acrylamide, 1 part by mass of ADT-250, and 2 parts by mass of Aqualon HS-1025 were emulsion polymerized in deionized water at 70° C. After polymerization was completed, the pH was adjusted to 7.0 using aqueous ammonia, yielding (meth)acrylic resin emulsion A with a solids content of 42.5% by mass. (Meth)acrylic resin emulsion S Using 0.5 parts by mass of ACVA as a polymerization initiator, 47 parts by mass of n-butyl acrylate, 22 parts by mass of methyl methacrylate, 9 parts by mass of 2-hydroxyethyl methacrylate, 15 parts by mass of methacrylic acid, 8 parts by mass of acrylamide, and 0.2 parts by mass of Aqualon HS-1025 were emulsion polymerized in deionized water at 70°C to obtain (meth)acrylic resin emulsion S with a solids content of 40% by mass.

[0067] Base film B 0 PEN film A polyethylene naphthalate film (corona-treated on both sides, thickness: 50 μm, manufactured by Toyobo Film Solutions Co., Ltd., Teonex Q83) was used. PET film A biaxially stretched polyethylene terephthalate film (double-sided corona treated, thickness 38 μm, manufactured by Toray Industries, Inc., Lumirror S10) was used.

[0068] Example 1 To prepare the adhesive layer (B1) on the support (A) side, 2.84 parts by mass of HDI isocyanurate (manufactured by Tosoh Corporation, trade name: Coronate HX), 50 parts by mass of dipentaerythritol penta / hexaacrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix M-402), 2.0 parts by mass of silicone diacrylate (manufactured by Daicel-Allnex Corporation, trade name: Ebecryl 350), and 2 parts by mass of Perkadox 12XL25 (manufactured by Kayaku Nouryon Co., Ltd.) were added to 250 parts by mass of (meth)acrylic resin solution L to obtain a coating solution for the adhesive layer (B1) on the support (A) side. This coating solution was applied to substrate B0 (PEN film) and dried at 100°C for 10 minutes to form an adhesive resin layer with a thickness of 25 μm. Next, a silicone release-treated polyethylene terephthalate film (separator) was attached to obtain a laminate of the adhesive layer (B1) / substrate (B0) on the support (A) side with the separator. The adhesive layer (B2) on the workpiece (C) was prepared by mixing 42.6 parts by weight of (meth)acrylic resin emulsion H, 57.4 parts by weight of (meth)acrylic resin emulsion B, 0.4 parts by weight of dimethylethanolamine, 3.4 parts by weight of an epoxy compound (Nagase ChemteX Corporation, product name: Ex-1610), 13 parts by weight of butyl carbinol, and 20 parts by weight of pure water. This coating solution was applied to a silicone release-treated polyethylene terephthalate film (separator) and dried at 120°C for 3 minutes to form an adhesive resin layer with a thickness of 13 μm. Next, this was bonded to the substrate (B0) side of the adhesive layer (B1) / substrate (B0) laminate described above to prepare a pre-heat-treated temporary bonding material (B) precursor with a three-layer structure of adhesive layer (B1) / substrate (B0) / adhesive layer (B2) with a separator. The separators used on both sides of the three-layer structure were peeled off, and the support (A) and work (C) shown in Table 1 were laminated using a vacuum laminator and heated at 140°C for 30 minutes to produce a laminate (D) consisting of the support (A) / temporary bonding material (B) / work (C) in that order. The mechanical peelability and removability of the laminate (D) were evaluated and the results are shown in Table 1. Separately, a laminate of adhesive layer (B1) / substrate (B0) and a laminate of adhesive layer (B2) / substrate (B0) were separately prepared (the coating conditions were the same), and the 10° peel strengths P1 and P2 were measured by the above-mentioned method. The measurement results are shown in Table 1.

[0069] Example 2 To prepare the adhesive layer (B1) on the support (A) side, 0.5 parts by mass of HDI isocyanurate (manufactured by Tosoh Corporation, trade name: Coronate HX), 12 parts by mass of dipentaerythritol penta / hexaacrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix M-400), 1.5 parts by mass of silicone diacrylate (manufactured by Daicel-Allnex Corporation, trade name: Ebecryl 350), and 2 parts by mass of Perkadox 12XL25 (manufactured by Kayaku Nouryon Co., Ltd.) were added to 270 parts by mass of (meth)acrylic resin solution N to obtain a coating solution for the adhesive layer (B1) on the support (A) side. This coating solution was applied to a silicone release-treated polyethylene terephthalate film (separator) and dried at 100°C for 10 minutes to form an adhesive resin layer 100 μm thick. Next, a substrate B0 (PET film) was attached to obtain a laminate of the adhesive layer (B1) / substrate (B0) on the support (A) side with a separator. Next, the coating liquid for the adhesive layer (B2) on the workpiece (C) side in Example 1 was applied to a silicone release-treated polyethylene terephthalate film (separator) and dried at 120°C for 3 minutes to form an adhesive resin layer with a thickness of 6 µm. This was then bonded to the substrate (B0) side of the adhesive layer (B1) / substrate (B0) laminate described above, thereby producing a pre-heat-treated temporary bonding material (B) precursor having a three-layer structure of adhesive layer (B1) / substrate (B0) / adhesive layer (B2) with a separator. The separators used on both sides of the three-layer structure were peeled off, and the support (A) and work (C) shown in Table 1 were laminated using a vacuum laminator and heated at 140°C for 30 minutes to produce a laminate (D) consisting of the support (A) / temporary bonding material (B) / work (C) in that order. The mechanical peelability and removability of the laminate (D) were evaluated and the results are shown in Table 1. Separately, a laminate of adhesive layer (B1) / substrate (B0) and a laminate of adhesive layer (B2) / substrate (B0) were separately prepared (the coating conditions were the same), and the 10° peel strengths P1 and P2 were measured by the above-mentioned method. The measurement results are shown in Table 1.

[0070] Example 3 An adhesive coating solution for temporary bonding material (B) was prepared by adding 1.0 part by weight of HDI isocyanurate (manufactured by Tosoh Corporation, product name: Coronate HX) and 2 parts by weight of Perkadox 12XL25 (manufactured by Nouryon Chemical Co., Ltd.) to 269 parts by weight of silicone-modified (meth)acrylic resin solution NS. This coating solution was applied to a silicone-release-treated polyethylene terephthalate film (separator) and then dried at 100°C for 10 minutes to form an adhesive resin layer 100 μm thick. A silicone-release-treated polyethylene terephthalate film (separator) was then attached to the film to prepare a pre-heat-treated temporary bonding material (B) precursor (with double-sided separators). The separators on both sides were peeled off, and the support plate (A) and workpiece (C) listed in Table 1 were laminated using a vacuum laminator. The laminate was then heated at 140°C for 30 minutes to produce a laminate (D) consisting of the support plate (A), temporary bonding material (B), and workpiece (C) in that order. The mechanical peelability and removability of the laminate (D) were evaluated, and the results are shown in Table 1. The 10° peel strengths P1 and P2 were measured according to the above method (when no base film (B0) was used as the temporary bonding material). The measurement results are shown in Table 1.

[0071] Example 4 The coating liquid for the adhesive layer (B1) on the support (A) side in Example 1 was applied to a silicone release-treated polyethylene terephthalate film (separator), and dried at 100°C for 10 minutes to form an adhesive resin layer having a thickness of 31 µm. Next, a substrate B0 (PET film) was attached to the coating liquid, thereby obtaining a separator-attached laminate of the adhesive layer (B1) on the support (A) side / substrate (B0). Next, a pressure-sensitive adhesive coating solution was prepared for the pressure-sensitive adhesive layer (B2) on the workpiece (C) by mixing 100 parts by weight of (meth)acrylic resin emulsion A, 0.7 parts by weight of (meth)acrylic resin emulsion S, 0.3 parts by weight of dimethylethanolamine, 5 parts by weight of an epoxy compound (Nagase ChemteX Corporation, product name: Ex-614), 9 parts by weight of butyl carbinol, and 12 parts by weight of pure water. This coating solution was applied to a silicone release-treated polyethylene terephthalate film (separator) and dried at 120°C for 3 minutes to form a pressure-sensitive adhesive resin layer with a thickness of 20 μm. Next, this was bonded to the substrate (B0) side of the pressure-sensitive adhesive layer (B1) / substrate (B0) laminate described above to prepare a pre-heat-treated temporary bonding material (B) precursor having a three-layer structure of pressure-sensitive adhesive layer (B1) / substrate (B0) / pressure-sensitive adhesive layer (B2) with a separator. The separators used on both sides of the three-layer structure were peeled off, and the support (A) and work (C) shown in Table 1 were laminated using a vacuum laminator and heated at 140°C for 30 minutes to produce a laminate (D) consisting of the support (A) / temporary bonding material (B) / work (C) in that order. The mechanical peelability and removability of the laminate (D) were evaluated and the results are shown in Table 1. Separately, a laminate of adhesive layer (B1) / substrate (B0) and a laminate of adhesive layer (B2) / substrate (B0) were separately prepared (the coating conditions were the same), and the 10° peel strengths P1 and P2 were measured by the above-mentioned method. The measurement results are shown in Table 1.

[0072] (Comparative Example 1) To 269 parts by weight of silicone-modified (meth)acrylic resin solution N, 0.1 parts by weight of HDI isocyanurate (manufactured by Tosoh Corporation, trade name: Coronate HX), 6 parts by weight of pentaerythritol tri / tetraacrylate (manufactured by Toagosei Co., Ltd., trade name: M-450), and 2 parts by weight of Perkadox 12XL25 (manufactured by Nouryon Chemical Co., Ltd.) were added to obtain an adhesive coating solution for temporary bonding material (B). This coating solution was applied to a silicone release-treated polyethylene terephthalate film (separator) and then dried at 100°C for 10 minutes to form an adhesive resin layer 50 μm thick. Next, a silicone release-treated polyethylene terephthalate film (separator) was attached to the film to prepare a precursor of temporary bonding material (B) before heat treatment (with double-sided separator). The separators on both sides were peeled off, and the support plate (A) and workpiece (C) shown in Table 1 were laminated using a vacuum laminator and heated at 140°C for 30 minutes to produce a laminate (D) consisting of the support (A) / temporary bonding material (B) / workpiece (C) in that order. The mechanical peelability and removability of the laminate (D) were evaluated and the results are shown in Table 1. The 10° peel strengths P1 and P2 were measured according to the above method (when no base film (B0) was used as the temporary bonding material). The measurement results are shown in Table 1.

[0073] [Table 1] [Industrial Applicability]

[0074] The workpiece processing method of the present invention can perform multiple and / or diverse processes on workpieces such as wafers with high productivity and yield without damaging electronic components such as functional layers formed on the workpieces such as wafers, and therefore greatly contributes to improving the productivity of electronic devices and has high applicability in various fields of industries such as the electronic component industry including the semiconductor process industry, the electrical and electronics industry that uses electronic components, the transportation machinery industry, the information and communications industry, and the precision machinery industry. [Explanation of symbols]

[0075] 11: Support (A) 12: Temporary fixing material (B) 13: Work (C) 14: Dicing tape 15: Ring frame 16: Remover 17: Adhesive tape 18: Adhesive layer (B2) on the workpiece (C) side 19: Base film (B0) 20: Adhesive layer (B1) on support (A) side 21: Polyimide film

Claims

1. A step (1) of stacking a support (A), a temporary fixing material (B), and a work (C) located on the side of the temporary fixing material (B) opposite to the support (A); A step (2) of subjecting the workpiece (C) to at least one treatment selected from heat treatment, mechanical processing, wet processing, and laser processing; A step (3) of separating the work (C) from the laminate (D) having the treated work (C); A method for processing a workpiece, comprising: The 10° peel strength P between the support (A) and the temporary fixing material (B) was measured while maintaining the angle between the peeled layers at 10°. １ and the 10° peel strength P between the temporary fixing material (B) and the work (C) ２ Ratio to P ２ / P １ is 1.1 or more.

2. Peel strength P １ The method for treating a workpiece according to claim 1, wherein the force is 10 N / 25 mm or less.

3. 3. The method for treating a workpiece according to claim 1, wherein the adhesive layer in contact with the support body (A) and the adhesive layer in contact with the workpiece (C) have different compositions.

4. A method for processing a workpiece according to any one of claims 1 to 3, wherein separation of the workpiece (C) from the laminate (D) is achieved by separating the support (A) from the temporary bonding material (B) and then removing the temporary bonding material (B) remaining on the workpiece (C).

5. 5. The method for treating a workpiece according to claim 4, wherein the method for separating the temporary bonding material (B) from the support (A) is mechanical peeling.

6. The method for treating a workpiece according to any one of claims 1 to 5, wherein the temporary fixing material (B) contains a curable adhesive component.

7. 6. The method for treating a workpiece according to claim 1, wherein the temporary fixing material (B) contains a release agent.

8. The temporary fixing material (B) is a base film (B ０ 8. The method for treating a workpiece according to claim 1, wherein the workpiece is a substrate having a pressure-sensitive adhesive material laminated on both sides thereof.

9. 9. The method for treating a workpiece according to claim 1, wherein the thickness of the workpiece (C) after treatment in step (2) is 1 μm or more and 200 μm or less.

10. 9. The method for treating a workpiece according to claim 1, wherein the thickness of the workpiece (C) is at least temporarily between 1 μm and 200 μm.

11. A method for manufacturing an electronic device, comprising a step of carrying out the method for treating a workpiece according to any one of claims 1 to 10.

12. The method for manufacturing an electronic device according to claim 11 , wherein the electronic device has a structure in which semiconductor chips are stacked.

13. A laminate (D) obtained by stacking a support (A), a temporary fixing material (B), and a work (C) located on the opposite side of the temporary fixing material (B) from the support (A), The 10° peel strength P between the support (A) and the temporary fixing material (B) was measured while maintaining the angle between the peeled layers at 10°. １ and the 10° peel strength P between the temporary fixing material (B) and the work (C) ２ Ratio to P ２ / P １ is 1.1 or more.

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