Stacked body and semiconductor device manufacturing method

Abstract

Provided is a laminate that can be implemented with a wide processing margin and without adhesive residue or damage to a semiconductor element in the transfer of the semiconductor element using laser light of various wavelengths. The laminate is obtained by laminating a substrate 1 having laser permeability, a resin film 1 and a resin film 2 in this order, wherein the light absorbance of the resin film 1 calculated for a film thickness of 1.0 μm at any wavelength of 200 nm to 1100 nm is 0.4-5.0, and the adhesive strength of the surface of the resin film 2 on the side opposite that of the resin film 1 side is 0.02-0.3 N / cm.

Description

[Technical Field]

[0001] The present invention relates to a laminate and a method for manufacturing a semiconductor device, and more particularly to a laminate that is suitably used when mounting a semiconductor element by laser transfer, and a method for manufacturing a semiconductor device using the same. [Background technology]

[0002] Typically, elements incorporated into semiconductor devices are transferred and mounted on circuit boards using a pick-and-place method such as a flip-chip bonder. In recent years, semiconductor devices have become increasingly compact and powerful, leading to smaller and thinner elements being incorporated into them. In recent years, displays in which light-emitting diodes (LEDs), a type of semiconductor element, are arranged in each pixel have attracted attention due to their high brightness, low power consumption, and high image quality. The LEDs mounted in each pixel are called micro LEDs, and are small LEDs with sides measuring several hundred to several dozen microns. Because the above mounting method takes too much time to manufacture these micro LED displays, new methods are being considered.

[0003] One method for mounting a large number of small semiconductor elements involves placing chips from a wafer onto a circuit board using an adhesive stamp made of silicone resin or the like (Patent Documents 1 and 2). In this method, the adhesive stamp can hold multiple micro LED chips, allowing multiple chips to be placed on a circuit board in a single pick-and-place process. Another proposed method involves transferring chips from a wafer to a transfer substrate with an adhesive layer, and then transferring and mounting them onto a circuit board or the like using laser lift-off (LLO) (Patent Documents 3, 4, and 5). This method has the advantage of enabling high-speed transfer with high positional accuracy. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2017-531915 [Patent Document 2] Japanese Patent Application Publication No. 2020-129638 [Patent Document 3] Japanese Patent Publication No. 2020-188037 [Patent Document 4] Japanese Patent Application Laid-Open No. 2010-251359 [Patent Document 5] Special Publication No. 2014-515883 Summary of the Invention [Problem to be solved by the invention]

[0005] In the inventions described in Patent Documents 1 and 2, the stamp size depends on the wafer size, limiting the number of semiconductor elements that can be simultaneously transferred. Furthermore, the inventions described in Patent Documents 1 and 2 also have issues, such as the need to create stamps that match the design of the circuit board each time. On the other hand, the LLO method eliminates area constraints and the need to create stamps with different designs, potentially reducing costs. However, in the inventions described in Patent Documents 3 and 4, for example, the adhesive layer is removed by laser ablation, but this requires the formation of a very thin adhesive layer, which raises concerns about reduced yield due to poor in-plane uniformity. Furthermore, in the inventions described in Patent Documents 3 and 4, excessive laser light must be irradiated to remove the entire adhesive layer by ablation in order to avoid residue of the adhesive layer on the surface of the semiconductor element and the adhesive layer scattering due to ablation, which could contaminate the substrate. This poses issues such as damage to the semiconductor element. (Hereinafter, the adhesive layer residue on the surface of the semiconductor element may be referred to as glue residue, and the scattered adhesive layer residue may be referred to as debris.) In Patent Document 5, by separating the adhesive layer and the laser absorption layer, transfer can be performed with low energy and damage to the semiconductor element can be reduced. However, there are issues with the processing margin to achieve practical transfer, such as a narrow range of laser energy that allows good transfer and changes in transferability depending on the laser intensity. [Means for solving the problem]

[0006] To solve the above problem, the present invention provides a laminate comprising a laser-transparent substrate 1, a resin film 1, and a resin film 2 laminated in this order, wherein the absorbance of resin film 1 at any wavelength of 200 to 1100 nm, converted into a film thickness of 1.0 μm, is 0.4 or more and 5.0 or less, and the adhesive strength of resin film 2 on the surface opposite to resin film 1 satisfies the requirement of 0.02 N / cm or more and 0.3 N / cm or less. [Effects of the Invention]

[0007] According to the laminate of the present invention, transfer of a semiconductor element using laser light of various wavelengths can be carried out with a wide processing margin without leaving adhesive residue or damaging the element. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a method for producing a laminate 2. A laminate in which semiconductor elements are stacked may be hereinafter referred to as a laminate 2. [Figure 2] 10A and 10B are diagrams illustrating a method for producing a laminate 2 using a temporary adhesive. [Figure 3] 1A to 1C are diagrams showing a method for producing a laminate 2 using laser lift-off. [Figure 4] 10A to 10C are diagrams showing another method for producing the laminate 2 using a semiconductor substrate. [Figure 5] 2A to 2C are diagrams illustrating a step of arranging the semiconductor element surface of the laminate 2 and the substrate 2 to face each other in the method for manufacturing the semiconductor device. [Figure 6] 10 is a diagram showing a process of transferring a semiconductor element onto a substrate 2 by irradiating with laser light. DETAILED DESCRIPTION OF THE INVENTION

[0009] The laminate of the present invention is a laminate comprising a laser-transmitting substrate 1, a resin film 1, and a resin film 2 laminated in this order, wherein the resin film 1 has an absorbance of 0.4 to 5.0 at a wavelength of 200 to 1100 nm when converted into a film thickness of 1.0 μm, and the resin film 2 has an adhesive strength of 0.02 N / cm to 0.3 N / cm on the surface opposite to the resin film 1 side. Hereinafter, the laminate of this embodiment will be referred to as laminate 1. Laminate 1 of the present invention and laminate 2 of the present invention may also be simply referred to as the laminate of the present invention.

[0010] Each component of the laminate 1 of the present invention will be described below.

[0011] The laser-transmitting substrate 1 refers to a substrate having an absorbance of 0.1 or less at any wavelength between 200 and 1100 nm. Substrates having such absorbance include inorganic substrates such as quartz, sapphire, alkali glass, non-alkali glass, and borosilicate glass. The thickness of the substrate can be selected within a range that does not impair the absorbance, and is preferably 0.1 mm to 5.0 mm. From the viewpoint of substrate handling, a thickness of 0.3 mm or more is preferred, and from the viewpoint of availability and versatility, a thickness of 2.0 mm or less is more preferred.

[0012] The laser-transmitting substrate 1 can also be an organic substrate such as PET, aramid, polyester, polypropylene, or cycloolefin. When using an organic substrate, the thickness can be selected within a range that does not impair the absorbance, and is preferably 0.05 mm to 3.0 mm. From the viewpoint of handling the substrate, a thickness of 0.1 mm or more is preferred, and from the viewpoint of suppressing light scattering during laser light irradiation, a thickness of 1.0 mm or less is more preferred.

[0013] Next, the resin film 1 will be described.

[0014] The resin film 1 is a film containing at least a resin, and has an absorbance of 0.4 or more and 5.0 or less at a wavelength of 200 to 1100 nm, calculated as a film thickness of 1.0 μm. The absorbance of 0.4 or more allows the resin film 1 to absorb the irradiated laser light intensively when the laser light is irradiated from the laser-transparent substrate 1 side to the resin film 1 side to transfer the semiconductor element to the opposing substrate. More preferably, the absorbance is 0.6 or more, allowing the laser light to be absorbed particularly near the outermost surface of the resin film 1, thereby enabling transfer with a laser light of even lower energy density. From the viewpoint of material design, the absorbance is preferably 5.0 or less, and more preferably 4.0 or less, allowing the use of versatile resins.

[0015] Resins contained in the resin film 1 include, but are not limited to, resins that have absorption in the range of 200 to 1100 nm, such as polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, urethane resin, novolac resin, polyhydroxystyrene, polyester resin, acrylic resin, and aramid resin.

[0016] These resins preferably have a conjugated structure within their structure. By having the resin have a conjugated structure, the absorbance of 200 to 1100 nm converted into a 1.0 μm film thickness can be adjusted to a range of 0.4 or more and 5.0 or less. Examples of structures having a conjugated structure include aromatic structures, and among these, structures such as biphenyl, imide, benzoxazole, and benzophenone are preferred. The absorbance can be adjusted to the above range by using monomer residues having a conjugated structure for 60 mol % or more of the monomer residues relative to 100 mol % of all monomer residues of the resin contained in the resin film 1. These resins may be contained in the resin film 1 alone or in combination.

[0017] The above absorbance can also be achieved by adding additives such as ultraviolet absorbers, dyes, dyes, and pigments. Examples of additives contained in the resin film 1 include ultraviolet absorbers such as Tinuvin PS, Tinuvin 99-2, Tinuvin 326, Tinuvin 328, Tinuvin 384-2, Tinuvin 400, Tinuvin 405, Tinuvin 460, Tinuvin 477, Tinuvin 479, Tinuvin 900, Tinuvin 928, and Tinuvin 1130 (all trade names, manufactured by BASF Ltd.), DAINSORB T-0, DAINSORB T-7, DAINSORB T-31, DAINSORB T-52, DAINSORB T-53, DAINSORB T-84, DAINSORB P-6, and DAINSORB P-7 (all trade names, manufactured by Daiwa Chemical Co., Ltd.), Solvent Yellow 93, Solvent Yellow 33, Solvent Orange 60, Solvent Red 111, Solvent Red 135, and Solvent Examples of the near-infrared absorbent include dyes such as Red 168, Solvent Red 207, Solvent Red 52, Solvent Red 179, Solvent Blue 36, Solvent Blue 94, Solvent Blue 63, Solvent Blue 104, Solvent Blue 97, Solvent Green 20, Solvent Violet 13, and Solvent Violet 36 (all trade names, manufactured by Tokyo Chemical Industry Co., Ltd.); infrared absorbents such as diimonium-based near-infrared absorbents, aminium-based near-infrared absorbents, anthraquinone-based near-infrared absorbents, phthalocyanine-based near-infrared absorbents, nickel complex-based near-infrared absorbents, polymethine-based near-infrared absorbents, diphenylmethane-based near-infrared absorbents, and triphenylmethane-based near-infrared absorbents; and pigments such as carbon black, perylene black, cyanine black, and aniline black.

[0018] These may be contained alone or in combination in the resin film 1. The content of the additive for setting the absorbance within the above range is preferably 0.1 parts by weight or more relative to 100 parts by weight of the resin film 1 of the present invention, and is preferably 50 parts by weight or less from the viewpoint of stability in the varnish state before forming the laminate.

[0019] The resin film 1 may further contain a silane compound as needed. By containing a silane compound, the adhesion between the resin film 1 and the laser-transparent substrate 1 can be adjusted. This prevents the resin film 1 in the portion not irradiated with the laser beam from peeling off from the laser-transparent substrate 1. Specific examples of silane compounds include N-phenylaminoethyltrimethoxysilane, N-phenylaminoethyltriethoxysilane, N-phenylaminopropyltrimethoxysilane, N-phenylaminopropyltriethoxysilane, N-phenylaminobutyltrimethoxysilane, N-phenylaminobutyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-methacryloxypropylmethyldiethoxysilane. The content of the silane compound is preferably 0.01 parts by weight or more and 15 parts by weight or less relative to 100 parts by weight of the resin film of the present invention.

[0020] Furthermore, the resin film 1 may contain a surfactant as needed to improve the coating properties with the laser-transparent substrate 1 during film formation and to form a resin film 1 with a uniform thickness.

[0021] The wavelength at which the resin film 1 satisfies the above absorbance is more preferably any one of 248 nm, 266 nm, 308 nm, 355 nm, 532 nm, and 1064 nm.The absorbance of the resin film 1 at any one of the wavelengths 248 nm, 266 nm, 308 nm, 355 nm, 532 nm, and 1064 nm, converted into a film thickness of 1.0 μm, is preferably 0.4 or more and 5.0 or less.

[0022] The wavelength at which the resin film 1 satisfies the above absorbance is more preferably 248 nm, 266 nm, or 355 nm. The absorbance of the resin film 1 at any of the wavelengths of 248 nm, 266 nm, and 355 nm, converted into a film thickness of 1.0 μm, is preferably 0.4 or more and 5.0 or less. By ensuring that the absorbance of the resin film 1 at these wavelengths falls within the above range, laser energy can be efficiently absorbed.

[0023] Next, the resin film 2 of the present invention will be described.

[0024] The adhesive strength of the surface of resin film 2 opposite to resin film 1 is 0.02 N / cm or more and 0.3 N / cm or less. The adhesive strength mentioned here refers to the value obtained from a 90°C peel test of the surface of resin film 2 opposite to resin film 1 and a Kapton film. The specific measurement method is to press a Kapton film cut to 1 cm x 9 cm onto the surface of resin film 2 opposite to resin film 1 of laminate 1 under conditions of 0.1 MPa and 25°C using a vacuum laminator, and then perform a peel test on the pressed Kapton tape in a direction perpendicular to resin film 2 at a constant speed of 2 mm / sec using a tensile tester.

[0025] When the adhesive strength is 0.02 N / cm or more, the semiconductor element can be stably held when stacked on the resin film 2. When the adhesive strength is 0.3 N / cm or less, the semiconductor element can be transferred with a laser beam having a low energy density during transfer. More preferably, the adhesive strength is 0.2 N / cm or less. By setting the adhesive strength within this range, adhesive residue on the semiconductor element can be suppressed when the semiconductor element is transferred by irradiating laser beam from the side of the laser-transparent substrate 1.

[0026] The resin film 2 contains at least a resin. To achieve the adhesive strength of the resin film 2 within the above range, the resin film 2 preferably contains a flexible or flexible component. Introducing a flexible or flexible component lowers the glass transition temperature, thereby increasing the adhesive strength. Examples of components that increase flexibility or flexibility include flexible structures derived from aliphatic groups or silanes such as alkylene groups or siloxanes, flexible structures derived from ether groups such as alkylene glycols or biphenyl ethers, alicyclic structures, and flexible structures such as olefins. By containing 20 mol % or more of the monomer residues having these flexibility-imparting structures relative to 100 mol % of all the monomer residues constituting the resin contained in the resin film 2, the adhesive strength can be increased to 0.02 N / cm or more. Furthermore, by containing 70 mol % or less of the monomer residues having these flexibility-imparting structures relative to 100 mol % of all the monomer residues constituting the resin contained in the resin film 2, the adhesive strength can be increased to 0.3 N / cm or less.

[0027] Resins contained in the resin film 2 include, but are not limited to, polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, urethane resin, novolac resin, polyester resin, acrylic resin, polyhydroxystyrene, polysiloxane, polyimidesiloxane, etc., within the range that satisfies the above-mentioned adhesive strength.

[0028] The resin film 2 in the laminate of the present invention preferably contains a crosslinking agent. When the resin film 2 contains a crosslinking agent, part of the structure is crosslinked, hardening the surface of the resin film 2 and making it possible to adjust the adhesive strength. Furthermore, the surface of the resin film 2 is crosslinked and hardened, thereby enhancing the effect of suppressing adhesive residue.

[0029] Examples of the crosslinking agent include compounds having an alkoxymethyl group or a methylol group, such as DML-PC, DML-PEP, DML-OC, DML-OEP, DML-34X, DML-PTBP, DML-PCHP, DML-OCHP, DML-PFP, DML-PSBP, DML-POP, DML-MBOC, DML-MBPC, DML-MTrisPC, DML-BisOC-Z, DMLBisOCHP-Z, DML-BPC, DML-BisOC-P, DMOM-PC, DMOM-PTBP, Examples of such polyethersulfones include DMOM-MBPC, TriML-P, TriML-35XL, TML-HQ, TML-BP, TML-pp-BPF, TML-BPE, TML-BPA, TML-BPAF, TML-BPAP, TMOM-BP, TMOM-BPE, TMOM-BPA, TMOM-BPAF, TMOM-BPAP, HML-TPPHBA, HML-TPHAP, HMOM-TPPHBA, and HMOM-TPHAP (all trade names, manufactured by Honshu Chemical Industry Co., Ltd.), and NIKALAC (registered trademark) MX-290, NIKALAC MX-280, NIKALAC MX-270, NIKALAC MX-279, NIKALAC MW-100LM, and NIKALAC MX-750LM (all trade names, manufactured by Sanwa Chemical Co., Ltd.).

[0030] It is also preferable to use a crosslinking agent having an epoxy group. Examples of compounds having an epoxy group include bisphenol A type epoxy resins, bisphenol F type epoxy resins, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, epoxy group-containing silicones such as polymethyl(glycidyloxypropyl)siloxane, and dimer acid-modified epoxy resins, but the present invention is not limited thereto. Specifically, Epicron 850-S, Epicron HP-4032, Epicron HP-7200, Epicron HP-820, Epicron HP-4700, Epicron EXA-4710, Epicron HP-4770, Epicron EXA-859CRP, Epicron EXA-1514, Epicron EXA-4880, Epicron EXA-4850-150, Epicron EXA-4850-1000, Epicron EXA-4816, Epicron EXA-4822 (all trade names, manufactured by Dainippon Ink and Chemicals, Inc.), Rikaresin Examples of such an agent include BEO-60E (hereinafter referred to as "trade name," manufactured by New Japan Chemical Co., Ltd.), EP-4003S, EP-4000S (all trade names, manufactured by Adeka Corporation), JER871, JER872, YX-4000, YX-4000H (all trade names, manufactured by Mitsubishi Chemical Corporation), Celloxide 2021P (all trade names, manufactured by Daicel Corporation), Showfree PETG, Showfree CDMGB, Showfree BATG (all trade names, manufactured by Showa Denko K.K.), Denacol EX-201-IM (all trade names, manufactured by Nagase ChemteX Corporation), and TEPIC-VL (all trade names, manufactured by Nissan Chemical Industries, Ltd.).

[0031] It is also preferable to have a crosslinking agent having an oxetanyl group, and specific examples include OXT-121, OXT-221, OX-SQ-H, OXT-191, PNOX-1009, RSOX (all trade names, manufactured by Toa Gosei Co., Ltd.), "Etanacol (registered trademark)" OXBP, and "Etanacol" OXTP (all trade names, manufactured by Ube Industries, Ltd.).

[0032] Two or more types of crosslinking agents may be contained in the resin film 2. By including preferably 1 part by weight or more in 100 parts by weight of the resin film 2, adhesive transfer can be reduced. More preferably, by including 5 parts by weight or more in 100 parts by weight of the resin film 2, a high adhesive transfer suppression effect can be obtained. Furthermore, the crosslinking agent is preferably included in 100 parts by weight of the resin film 2 in an amount of 300 parts by weight or less. Within this range, the flexibility of the resin film 2 is maintained, and the resin film 2 is not torn during transfer of the semiconductor element. Furthermore, from the viewpoint of storage stability in the varnish state prior to forming the laminate, the content is more preferably 200 parts by weight or less. In particular, when the adhesive strength of the resin itself exceeds 0.3 N / cm, the preferred content of the crosslinking agent is 5 parts by weight or more and 300 parts by weight or less in 100 parts by weight of the resin film 2. By including 5 parts by weight or more of the crosslinking agent, the adhesive strength of a resin having an adhesive strength of 0.3 N / cm or more can be reduced to 0.3 N / cm or less. By including 300 parts by weight or less, the flexibility of the resin film 2 is maintained. In addition, the amount is preferably 10 parts by weight or more since it also has the effect of suppressing adhesive residue, and is preferably 200 parts by weight or less since it also improves storage stability.

[0033] Furthermore, a curing accelerator may be added to accelerate the curing by the crosslinking agent. Examples of the curing accelerator include imidazoles, tertiary amines or their salts, and organic boron salt compounds, among which imidazoles are preferred. Specific examples of imidazoles include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-n-propylimidazole, 2-undecyl-1H-imidazole, 2-heptadecyl-1H-imidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-1H-imidazole, 4-methyl-2-phenyl-1H-imidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-benzyl-4-methylimidazole, 2 ... 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazolium trimellitate, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-di Amino-6-[2′-methylimidazolyl-(1′)]-ethyl-s-triazine, 2,4-diamino-6-[2′-undecylimidazolyl-(1′)]-ethyl-s-triazine, 2,4-diamino-6-[2′-ethyl-4-methylimidazolyl-(1′)]-ethyl-s-triazine, 2,4-diamino-6-[2′-methylimidazolyl-(1′)]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2- Examples include methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-cyanoethyl-2-phenyl-4,5-di(2-cyanoethoxy)methylimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 1-benzyl-2-phenylimidazole hydrochloride, and 1-benzyl-2-phenylimidazolium trimellitate.Preferred examples of commercially available imidazoles include Curesol C17Z, Curesol 2MZ, Curesol 1B2MZ, Curesol 2E4MZ, Curesol 2E4MZ-CN, Curesol 2MZ-AZINE, and Curesol 2MZ-OK (all trade names manufactured by Shikoku Chemicals Corporation).

[0034] The content of the curing accelerator in the resin film 2 is preferably 0.1 parts by weight or more and 5.0 parts by weight or less, based on 100 parts by weight of the resin film 2. Within this range, a sufficient crosslinking promoting effect can be obtained. Furthermore, from the viewpoint of maintaining the stability of the varnish in its state before forming the laminate, a content of 0.5 to 2.0 parts by weight is even more preferable.

[0035] The laminate of the present invention may have another layer interposed therebetween as long as the order of lamination is laser-transmittable substrate 1, resin film 1, and resin film 2. However, laser-transmittable substrate 1 and resin film 2 are located on the outermost surfaces of the laminate.

[0036] The laminate of the present invention is a laminate comprising a laser-transmitting substrate 1, a resin film 1, a resin film 2, and a semiconductor element laminated in this order, wherein the absorbance of the resin film 1 at any wavelength of 200 to 1100 nm, converted into a film thickness of 1.0 μm, is 0.4 or more and 5.0 or less, and the adhesive strength of the surface where the resin film 2 and the semiconductor element contact is 0.02 N / cm or more and 0.3 N / cm or less.

[0037] The explanation of the laser-transmitting substrate 1 and the resin films 1 and 2 in the laminate 2 is the same as that for the laminate 1.

[0038] Next, the semiconductor element of the present invention will be described.

[0039] The semiconductor element in the present invention includes semiconductors such as GaN, AlN, InN, InP, GaAs, Si, and SiC that are fabricated into an element. These semiconductor elements also include those in which different types of semiconductors are further stacked, and those in which electrode materials, sapphire substrates, glass substrates, wiring, etc. are stacked. The size of the semiconductor element is preferably 5 μm or more and 5.0 mm or less on one side. More preferably, it is 3.0 mm or less, and since the laser light can be focused and irradiated with a small spot diameter, transfer with high positional accuracy is possible.

[0040] The number of semiconductor elements mounted on the laminate 2 of the present invention is 5 / cm per unit area. 2 More preferably, 50 particles / cm 2 That's all. By increasing the number of semiconductor elements beyond this, the effect of improving throughput by using laser transfer becomes greater. In addition, since the laser light can be accurately irradiated onto each semiconductor element, it is possible to achieve a density of 500,000 elements / cm. 2 Preferably, it is equal to or less than 100,000 particles / cm, and more preferably, it is equal to or less than 100,000 particles / cm. 2 The following is preferred:

[0041] The stacking order of the laminate 2 of the present invention is laser-transparent substrate 1, resin film 1, resin film 2, and semiconductor element, and may include other layers in between. However, the semiconductor element is formed directly on resin film 2, and the laser-transparent substrate 1 and semiconductor element are located on the outermost surfaces of the laminate.

[0042] The laminate of the present invention preferably has an indentation hardness H2 of 2 MPa or more and 500 MPa or less, measured by pressing from the resin film 2 side to the substrate 1 side, and when the resin film 2 is removed from the laminate and the indentation hardness measured by pressing from the resin film 1 side to the substrate 1 side is defined as H1, it satisfies H1>H2.

[0043] In the case of the laminate 2, the indentation hardness H2, measured by pressing from the resin film 2 side to the substrate 1 side with the semiconductor element removed from the laminate 2, is preferably 2 MPa or more and 500 MPa or less, and when the indentation hardness H1, measured by pressing from the resin film 1 side to the laser-transparent substrate 1 side with the semiconductor element and resin film 2 removed from the laminate 2, is H1, it is preferable that H1 > H2. The indentation hardness is a physical property that serves as an indicator when stacking the semiconductor element on the resin film 2, and setting the indentation hardness within an appropriate range makes it easier to stack the semiconductor element on the resin film 2 and can increase the accuracy of the subsequent transfer of the semiconductor element by laser light irradiation.

[0044] The indentation hardness H2 can be measured using a nanoindenter. For laminate 2, the hardness can be measured by physically removing the semiconductor element from laminate 2 to expose the surface of resin film 2. The semiconductor element can be removed directly using tweezers or by placing a highly adhesive substrate or film, such as dicing tape, on top of the semiconductor element and peeling it off. Indentation hardness is measured using a Berkovich indenter (a triangular pyramidal diamond indenter) at room temperature and in air, in an indentation load / unload test in which the sample is indented from the surface of resin film 2 toward resin film 1, and then unloaded. The measurement is performed using a continuous stiffness measurement method at a measurement frequency of 100 Hz. From the load-indentation depth diagram obtained, the indentation hardness can be calculated using the indentation region not affected by the underlying substrate.

[0045] For laminate 1, the indentation hardness H1 is measured by removing resin film 2 by dry etching to expose the surface of resin film 1. For laminate 2, the semiconductor element is physically removed using the method described above, and then resin film 2 is removed by dry etching to expose the surface of resin film 1. Dry etching of resin film 2 is performed in advance at a location different from the measurement location, the etching rate of resin film 2 is calculated, and resin film 2 is removed based on the results. The components of the surface of the resin film are then analyzed using ATR-IR, and removal of resin film 2 can be confirmed when the components of resin film 2 are no longer detected. Indentation hardness H1 can be measured using a nanoindenter, just like indentation hardness H2. The nanoindenter conditions for measuring indentation hardness H1 are the same as those for measuring indentation hardness H2.

[0046] When the indentation hardness H2, measured by pressing from the resin film 2 side to the substrate 1 side, is 2 MPa or more, the semiconductor element will not be embedded in the resin film 2 even when the element is laminated on the resin film 2 by pressure bonding using a vacuum laminator, wafer bonder, or the like. Since the resin film 2 does not adhere to the side surface of the semiconductor element, transfer is possible with a low-energy-density laser beam. Furthermore, when the indentation hardness H2 is 500 MPa or less, the semiconductor element can be laminated without being damaged even when pressure is applied during lamination. More preferably, the indentation hardness H2 is 300 MPa or less. When the indentation hardness H2 is 300 MPa or less, the yield when laminating semiconductor elements on the resin film 2 is improved.

[0047] Furthermore, when comparing the indentation hardness H1 and the indentation hardness H2, by satisfying H1>H2, the interface between resin film 1 and resin film 2 is kept uniform when the semiconductor element is pressed onto resin film 2, and the positional accuracy when transferring with laser light is improved.

[0048] In the laminate of the present invention, where t1 (μm) is the thickness of resin film 1 and t2 (μm) is the thickness of resin film 2, it is preferable that (t1 + t2) is 1.0 μm or more and 30 μm or less, and t1 / t2 is 0.1 or more and 5.0 or less. Having (t1 + t2) of 1.0 μm or more reduces the transfer of heat generated during laser light irradiation to the semiconductor element, thereby suppressing damage to the semiconductor element. Furthermore, having (t1 + t2) of 30 μm or less allows deformation caused by ablation of resin film 1 due to laser light irradiation from the laser-transparent substrate 1 side to be efficiently transferred to the interface between resin film 2 and the semiconductor element, resulting in transfer of the semiconductor element. More preferably, (t1 + t2) is 20 μm or less, which allows the semiconductor element to be transferred to the opposing substrate with high positional accuracy.

[0049] Furthermore, it is preferable that t1 / t2 is 0.1 or more and 5.0 or less. If t1 / t2 is 0.1 or more, when laser light is irradiated from the laser-transparent substrate 1 side, the energy generated by ablation of resin film 1 reaches the interface with the semiconductor element without attenuation in resin film 2, allowing the semiconductor element to be transferred. If t1 / t2 is 5.0 or less, breakage of resin film 2 due to the energy generated by ablation of resin film 1 by laser light irradiation can be suppressed. As a result, it is possible to prevent a portion of resin film 1 or resin film 2 from scattering as debris onto the opposing substrate and damaging the substrate. More preferably, t1 / t2 is 0.3 or more and 3.0 or less.

[0050] The breaking elongation of the resin film 1 in the laminate of the present invention is preferably 2.0% or more and 30% or less. When the breaking elongation of the resin film 1 is 2.0% or more, peeling of the resin film 1 from an adjacent substrate or film due to an impact other than laser light irradiation can be prevented.

[0051] Furthermore, if the breaking elongation of resin film 1 is 30% or less, when laser light is irradiated, resin film 1 breaks at the boundary between the irradiated and unirradiated areas, allowing for accurate transfer of only the semiconductor element in the irradiated area. The transfer of semiconductor elements by laser light irradiation typically involves ablation of the laser light absorption layer at the interface between the laser-transparent substrate and the laser light absorption layer, and the pressure of the generated decomposition gas transfers the semiconductor element. In the laminate of the present invention, in addition to the above effects, the laser-irradiated portion of resin film 1 breaks and falls onto resin film 2. This allows the impact of the falling of the broken resin film 1 to be used as energy for transferring the semiconductor element, improving positional accuracy and enabling transfer even with low-energy laser light irradiation, significantly improving processing margins.

[0052] The breaking elongation of the resin film 1 is more preferably 5% or more and 25% or less. If the breaking elongation of the resin film 1 is 5% or more, the possibility of the resin film 1 peeling off due to a reason other than laser light irradiation is further reduced, making it easier to store and transport the laminate. Furthermore, if the breaking elongation of the resin film 1 is 25% or less, transfer with lower energy is possible, which is more preferable.

[0053] In order for the resin to satisfy the above-mentioned breaking elongation requirement for the resin film 1, it is preferable that the resin contained in the resin film 1 has a rigid structure. The rigid structure is preferably a structure having an aromatic ring, a condensed ring, an olefin, an alkyl group having about 1 to 3 carbon atoms, or the like. Among these, the rigid structure is preferably an aromatic ring or a condensed ring, in order not to impair absorbance. Because a rigid structure is difficult to stretch, the breaking elongation can be 30% or less. Furthermore, because it has a strong structure, the breaking elongation can be 2% or more. Specifically, the breaking elongation can be within the above-mentioned range by having 50 mol % or more of the monomer residues having a rigid structure relative to 100 mol % of all the monomer residues constituting the resin contained in the resin film 1.

[0054] Furthermore, the breaking elongation of the resin film 1 can be adjusted to a range of 2.0% to 30% by adjusting the ratio of monomers during resin polymerization to adjust the molecular weight. For example, when polyimide is used for the resin film 1, the molecular weight of the resin can be reduced by shifting the ratio of diamine and acid dianhydride used as monomers from equal amounts during polymerization to a differential ratio of, for example, 98 mol:100 mol. Generally, lowering the molecular weight of the resin reduces entanglement between molecules, thereby lowering the breaking elongation. For resins with a breaking elongation of 30% or more, lowering the molecular weight using the above method can reduce the breaking elongation to 30% or less. On the other hand, for resins with a breaking elongation of less than 2%, increasing the molecular weight can increase the breaking elongation to 2% or more. The preferred range of the resin molecular weight is a weight-average molecular weight of 1,000 to 100,000.

[0055] When forming the resin film 1, the breaking elongation of the film can be controlled by controlling the packing state of the resin through heat treatment. Examples of such a structure include planar packing of aromatic rings in structures containing aromatic rings, and packing of alkyl chains in structures containing alkyl chains. For example, if the resin contained in the resin film 1 is a polyimide containing aromatic rings, if the heat treatment temperature is lower than 200°C, the packing of the aromatic rings in the resin will be insufficient, resulting in a low breaking elongation. On the other hand, by setting the heat treatment temperature to 200°C or higher within the heat resistance range of the resin, the breaking elongation can be increased. Furthermore, the breaking elongation is lower when cured in air than when cured in an inert gas atmosphere. By combining these film formation methods in addition to the resin composition, the breaking elongation within the above range can be achieved.

[0056] The laminate of the present invention preferably has an indentation hardness H1 of 50 MPa or more and 1000 MPa or less, measured by indenting from the resin film 1 side to the substrate 1 side. When the indentation hardness H1 is in this range, the resin film 1 is easily broken when irradiated with laser light, and transferability is improved.

[0057] To achieve this range of indentation hardness H1, the resin contained in the resin film 1 must contain at least 50 mol % aromatic ring-containing monomer residues, relative to 100 mol % of all monomer residues constituting the resin. Furthermore, since the indentation hardness H1 varies depending on the packing properties of the resin, as with the elongation mentioned above, it can also be adjusted by changing the curing temperature when forming the resin film 1. Specifically, the indentation hardness H1 decreases when the heat treatment temperature of the resin film 1 is lowered below 200°C, whereas the indentation hardness H1 increases when the heat treatment temperature is higher than 200°C. The optimal temperature and range of hardness that can be adjusted vary depending on the type of resin. For example, if the resin film 1 contains polyamic acid, the conversion of polyamic acid to imide occurs in the range of 180°C to 300°C, changing the packing properties of the film and allowing adjustment of hardness. Furthermore, the addition of a crosslinking agent can also increase hardness by crosslinking the film, so low-hardness resins can be adjusted by using them in combination with a crosslinking agent.

[0058] A more preferable range of the indentation hardness H1 measured by indenting from the resin film 1 side to the substrate 1 side is 80 MPa to 800 MPa. By setting it in this range, the positional accuracy of the elements transferred by laser light irradiation can be further improved.

[0059] The breaking elongation of the resin film 2 in the laminate of the present invention is preferably 100% or more and 1000% or less. In the present invention, the resin film 2 not only functions to hold the semiconductor element, but also functions to receive the resin film 1 broken by laser light irradiation during the transfer process, and use the momentum to peel the semiconductor element from the surface of the resin film 2 and transfer it. When the breaking elongation of the resin film 2 is 100% or more, the resin film 2 does not break even when receiving the broken resin film 1. This suppresses the generation of debris from the resin film 1 and the resin film 2 during transfer, and prevents contamination of the opposing substrate. Furthermore, when the breaking elongation of the resin film 2 is 1000% or less, it is possible to prevent deformation of the resin film 2 in the non-laser light irradiated portion due to tension caused by deformation of the resin film 2 in the laser light irradiated portion. More preferably, it is 200% or more and 800% or less. This range allows for a wider range of energy densities of the laser light that can be irradiated, resulting in improved processing margins.

[0060] To achieve such physical properties in the resin film 2, it is preferable that the resin contained in the resin film 2 has a flexible structure. Examples of flexible structures include alkylene structures, siloxane structures, and alkylene glycol structures. Specifically, this can be achieved by making 20 mol % or more of the monomer residues in the resin contained in the resin film 2, relative to 100 mol % of all monomer residues constituting the resin, monomer residues having a flexible structure. More preferably, relative to 100 mol % of all monomer residues constituting the resin, 30 mol % or more of the monomer residues have a flexible structure.

[0061] In the laminate of the present invention, it is preferable that the resin film 1 contains one or more selected from the group consisting of polyimide having a structure of formula (1), polyimide precursor having a structure of formula (2), polybenzoxazole having a structure of formula (3), polybenzoxazole precursor having a structure of formula (4), and copolymers thereof.

[0062] [ka]

[0063] In formulas (1) to (4), R 1 , R 3 , R 7 and R 9 each independently represents a tetravalent organic group having 6 to 40 carbon atoms, and R 2 , R 4 , R 6 and R 8 R each independently represents a divalent organic group having 2 to 40 carbon atoms. 5 represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0064] Polyimide and polybenzoxazole are resins having a cyclic structure of an imide ring or an oxazole ring within the main chain structure. Their precursors, polyimide precursors and polybenzoxazole precursors, are resins that form an imide ring or a benzoxazole ring structure by dehydration ring closure. The resin preferably contains 10 to 100,000 repeating units of the structures shown in formulas (1) to (4). Within this range, the resin film 1 can be applied to an appropriate thickness.

[0065] Polyimides can be obtained by reacting tetracarboxylic acids, the corresponding tetracarboxylic dianhydrides, or tetracarboxylic diester dichlorides with diamines, the corresponding diisocyanates, or trimethylsilylated diamines, and contain both tetracarboxylic acid and diamine residues. For example, polyamic acids, which are polyimide precursors obtained by reacting tetracarboxylic dianhydrides with diamines, can be obtained by dehydrating and cyclizing the polyamic acid through heat treatment. A water-azeotropic solvent, such as m-xylene, can be added during this heat treatment. Alternatively, polyimides can be obtained by dehydrating and cyclizing the polyamic acid through chemical heat treatment using a ring-closing catalyst, such as a carboxylic anhydride, a dehydrating condensation agent, such as dicyclohexylcarbodiimide, or a base, such as triethylamine. Alternatively, polyimides can be obtained by adding a weakly acidic carboxylic acid compound and then heating the resulting mixture at a low temperature (below 100°C) to dehydrate and cyclize the polyamic acid.

[0066] Polybenzoxazole can be obtained by reacting a bisaminophenol compound with a dicarboxylic acid, the corresponding dicarboxylic acid chloride, or a dicarboxylic acid activated ester, and contains a dicarboxylic acid residue and a bisaminophenol residue. For example, polyhydroxyamide, a polybenzoxazole precursor obtained by reacting a bisaminophenol compound with a dicarboxylic acid, can be obtained by dehydrating and cyclizing the polyhydroxyamide through heat treatment. Alternatively, it can be obtained by adding phosphoric anhydride, a base, a carbodiimide compound, or the like and then dehydrating and cyclizing the polybenzoxazole through chemical treatment.

[0067] In formula (1) and formula (2), R 1 and R 3 (COOR 5 ) represents a tetracarboxylic acid residue. 1 or R 3 (COOR 5Examples of the tetracarboxylic acid residues constituting the tetracarboxylic acid include pyromellitic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, 2,2',3,3'-biphenyltetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 2,2',3,3'-benzophenonetetracarboxylic acid, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane, 2,2-bis(2,3-dicarboxyphenyl)hexafluoropropane, 1,1-bis(3,4-dicarboxyphenyl)ethane, 1,1-bis(2,3-dicarboxyphenyl)ethane, Examples of the tetracarboxylic acid residue include aromatic tetracarboxylic acid residues such as bis(3,4-dicarboxyphenyl)ethane, bis(3,4-dicarboxyphenyl)methane, bis(2,3-dicarboxyphenyl)methane, bis(3,4-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)ether, 1,2,5,6-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,5,6-pyridinetetracarboxylic acid, and 3,4,9,10-perylenetetracarboxylic acid, and aliphatic tetracarboxylic acid residues such as butanetetracarboxylic acid and 1,2,3,4-cyclopentanetetracarboxylic acid. The tetracarboxylic acid residue may contain residues of two or more of these tetracarboxylic acids. From the viewpoint of absorbance, aromatic tetracarboxylic acid residues are preferred.

[0068] In formula (1) and formula (2), R 2 and R 4 represents a diamine residue. 2 or R 4Examples of the diamine residue constituting the formula include hydroxyl group-containing diamine residues such as 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, bis(3-amino-4-hydroxyphenyl)sulfone, 2,2-bis(3-amino-4-hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)methane, bis(3-amino-4-hydroxyphenyl)ether, 3,3'-diamino-4,4'-biphenol, and 9,9-bis(3-amino-4-hydroxyphenyl)fluorene; 3-sulfone Sulfonic acid group-containing diamine residues such as 4,4'-diaminodiphenyl ether, thiol group-containing diamine residues such as dimercaptophenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 1,4-bis(4-aminophenoxy) Benzene, benzidine, m-phenylenediamine, p-phenylenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, bis(4-aminophenoxyphenyl)sulfone, bis(3-aminophenoxyphenyl)sulfone, bis(4-aminophenoxy)biphenyl, bis{4-(4-aminophenoxy)phenyl}ether, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl Examples of the aromatic diamine residues include aromatic diamine residues such as 2,2',3,3'-tetramethyl-4,4'-diaminobiphenyl, 2,2',3,3'-tetramethyl-4,4'-diaminobiphenyl, 3,3',4,4'-tetramethyl-4,4'-diaminobiphenyl, and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl; compounds in which some of the hydrogen atoms in these aromatic rings have been substituted with alkyl groups or fluoroalkyl groups having 1 to 10 carbon atoms, halogen atoms, or the like; and alicyclic diamine residues such as cyclohexyldiamine and methylenebiscyclohexylamine.Aliphatic diamine residues can also be used. Examples of diamine residues containing a polyethylene oxide group include diamine residues such as JEFFAMINE KH-511, JEFFAMINE ED-600, JEFFAMINE ED-900, JEFFAMINE ED-2003, JEFFAMINE EDR-148, JEFFAMINE EDR-176, and polyoxypropylene diamines D-200, D-400, D-2000, and D-4000 (all trade names, manufactured by HUNTSMAN Co., Ltd.); and diamine residues having a polyalkylene oxide group include residues of Elasmer 250P, Elasmer 650P, Elasmer 1000P, and Porea SL100A (all trade names, manufactured by Kumiai Chemical Industry Co., Ltd.). Furthermore, siloxane diamine residues can also be used, such as residues of propylamine-terminated siloxane diamines such as LP-7100, KF-8010, KF-8012, and X-22-161A (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.). Two or more of these diamine residues may also be contained in combination. From the viewpoint of absorbance, it is preferable that the resin film 1 contain 30 mol % or more of aromatic diamine residues relative to the total diamine residues in the resin film 1.

[0069] In formula (2), R 5 represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. Examples of the organic group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, an octyl group, a dodecyl group, and a phenyl group. In view of the ease of obtaining raw materials for polymerization, a methyl group and an ethyl group are preferred.

[0070] In formula (3) and formula (4), R 6 and R 8 represents a dicarboxylic acid, tricarboxylic acid, or tetracarboxylic acid residue.

[0071] Examples of dicarboxylic acid residues include residues of terephthalic acid, isophthalic acid, diphenyl ether dicarboxylic acid, bis(carboxyphenyl)hexafluoropropane, biphenyl dicarboxylic acid, benzophenone dicarboxylic acid, and triphenyl dicarboxylic acid, and examples of tricarboxylic acid residues include residues of trimellitic acid, trimesic acid, diphenyl ether tricarboxylic acid, and biphenyl tricarboxylic acid. Examples of tetracarboxylic acid residues include R 1 and R 3 It is the same as the residues given as examples of the residues of the group 1. Two or more of these may be contained.

[0072] In formula (3) and formula (4), R 7 and R 9 (OH)2 represents a bisaminophenol derivative residue. Specific examples of the bisaminophenol derivative residue include, but are not limited to, residues of 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, bis(3-amino-4-hydroxyphenyl)propane, bis(4-amino-3-hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)sulfone, bis(4-amino-3-hydroxyphenyl)sulfone, 2,2-bis(3-amino-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane, and 2,2-bis(4-amino-3-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane. These compounds may be contained alone or in combination of two or more.

[0073] Furthermore, it is preferable to cap the terminals of the resins represented by formulas (1) to (4) with a monoamine, acid anhydride, acid chloride, or monocarboxylic acid having an acidic group, since this makes it possible to obtain a resin having an acidic group at the terminal of the main chain.

[0074] Preferred examples of such monoamines include 2-aminophenol, 3-aminophenol, 4-aminophenol, etc. Two or more of these may be used.

[0075] Preferred examples of such acid anhydrides, acid chlorides, and monocarboxylic acids include known compounds such as phthalic anhydride, maleic anhydride, and nadic anhydride. Di-tert-butyl dicarbonate is also preferably used as a reactive terminal. Two or more of these may be used.

[0076] In the laminate of the present invention, it is preferable that the resin contained in the resin film 2 has one or more structures selected from the group consisting of a dimethylsiloxane structure represented by formula (5), a diphenylsiloxane structure represented by formula (6), an alkylene glycol structure represented by formula (7), and an alkylene structure represented by formula (8).

[0077] [ka]

[0078] In formulas (5) to (8), R 10 ~R 13 each independently represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. l, m, and n each independently represent an integer of 4 to 40. p represents an integer of 10 to 40. o represents an integer of 1 to 16.

[0079] The resin preferably has the structures represented by formulas (5) to (8) in its structure, which has the effect of improving the flexibility and adhesive strength of the resin film 2. 10 ~R 13 is R 5 This is the same as the explanation above.

[0080] Specific examples of such structures include aliphatic diamine residues, such as diamine residues containing a polyethylene oxide group, including diamine residues such as JEFFAMINE KH-511, JEFFAMINE ED-600, JEFFAMINE ED-900, JEFFAMINE ED-2003, JEFFAMINE EDR-148, JEFFAMINE EDR-176, and polyoxypropylene diamines D-200, D-400, D-2000, and D-4000 (all trade names, manufactured by HUNTSMAN Co., Ltd.), and diamine residues having a polyalkylene oxide group, including residues of Elasmer 250P, Elasmer 650P, Elasmer 1000P, and Porea SL100A (all trade names, manufactured by Kumiai Chemical Industry Co., Ltd.). Further examples of the siloxane diamine residue include residues of propylamine-terminated siloxane diamines such as LP-7100, KF-8010, KF-8012, and X-22-161A (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.). Two or more of these diamine residues may be used in combination.

[0081] In the laminate of the present invention, it is more preferable that the resin contained in the resin film 2 is polyimidesiloxane. Polyimidesiloxane is a resin having a siloxane structure in a polyimide repeating structure, and it is particularly preferable that the polyimidesiloxane in the present invention has a siloxanediamine residue represented by formula (9) in the structure.

[0082] [ka]

[0083] In formula (9), q is a natural number from 1 to 50. 14 and R 15 may be the same or different and represent an alkylene group or a phenylene group having 1 to 30 carbon atoms. 16 ~R 19 may be the same or different and represent an alkyl group having 1 to 30 carbon atoms, a phenyl group, or a phenoxy group.

[0084] The siloxane diamine residue represented by formula (9) includes α,ω-bis(3-aminopropyl)polydimethylsiloxane, α,ω-bis(3-aminopropyl)polydiethylsiloxane, α,ω-bis(3-aminopropyl)polydipropylsiloxane, α,ω-bis(3-aminopropyl)polydibutylsiloxane, α,ω-bis(3-aminopropyl)polydiphenoxysiloxane, α,ω-bis(2-aminoethyl)polydimethylsiloxane, α,ω-bis(2- Examples of the siloxane diamine include residues of α,ω-bis(4-aminoethyl)polydiphenoxysiloxane, α,ω-bis(4-aminobutyl)polydimethylsiloxane, α,ω-bis(4-aminobutyl)polydiphenoxysiloxane, α,ω-bis(5-aminopentyl)polydimethylsiloxane, α,ω-bis(5-aminopentyl)polydiphenoxysiloxane, α,ω-bis(4-aminophenyl)polydimethylsiloxane, and α,ω-bis(4-aminophenyl)polydiphenoxysiloxane. The above siloxane diamines may be used alone or in combination of two or more.

[0085] In the laminate of the present invention, the resin film 2 preferably has a 1% weight loss temperature of 300°C or higher. Here, the 1% weight loss temperature of the resin film 2 refers to the value obtained by heat-treating the resin film 2 at 250°C for 30 minutes. For resin films 2 that have already been heat-treated, this can also be confirmed by heat-treating them at 250°C for 30 minutes. A 1% weight loss temperature of 300°C or higher can suppress deterioration of the resin film 2 itself due to heat generated during laser light irradiation, and prevent the generation of debris due to deterioration of the resin film 2. To achieve a 1% weight loss temperature of 300°C or higher, the resin film 2 preferably contains a component with high thermal stability. Specific examples of a component with high thermal stability include rigid components such as aromatic rings, siloxanes with relatively high thermal stability even among flexible structures, and combinations thereof. When 50% or more of the monomer residues are the above-mentioned highly thermally stable monomer residues relative to 100 mol% of all monomer residues constituting the resin contained in the resin film 2, the 1% weight loss temperature can be achieved at 300°C or higher. From the viewpoint of versatility of the polymer, the 1% weight loss temperature is preferably 600°C or lower.

[0086] Next, a method for producing the laminate of the present invention will be described.

[0087] Laminate 1 is obtained by forming resin film 1 and resin film 2 in this order on laser-transparent substrate 1. An example of a method for producing laminate 1 will be described. Resin film 1 is produced by applying a varnish, in which the components of resin film 1 are dissolved in a solvent, to laser-transparent substrate 1 and then heat-curing the varnish. Resin film 2 is then formed by applying a varnish for resin film 2 to resin film 1 in a similar manner and then heat-curing the substrate. When producing resin films 1 and 2 by coating, any coating method can be selected, including spin coating using a spinner, spray coating, roll coating, and slit die coating. After coating, resin films 1 and 2 are preferably dried for one minute to several tens of minutes at 50°C to 150°C using a hot plate, drying oven, infrared radiation, or the like. If necessary, the resin films are then heat-cured at 100°C to 500°C for several minutes to several hours.

[0088] The thickness of resin film 1 is selected between 0.1 μm and 25 μm. The thickness of resin film 2 is selected between 0.2 μm and 27 μm. The thickness can be measured using a scanning electron microscope, an optical film thickness meter, a step gauge, or the like.

[0089] It is also possible to provide another layer between the laser-transparent substrate 1 and the resin film 1, and between the resin film 1 and the resin film 2. When providing another layer between the laser-transparent substrate 1 and the resin film 1, a film is formed on the laser-transparent substrate 1 before the resin film 1 is fabricated. When forming another layer between the resin film 1 and the resin film 2, the other layer can be formed on the fabricated resin film 1, and then the resin film 2 can be formed.

[0090] Next, an example of a method for forming the laminate 2 by stacking a semiconductor element on the laminate 1 will be described.

[0091] FIG. 1 shows a method for producing laminate 2 (120). Laminate 1 (110) is obtained by laminating resin film 1 (12) and resin film 2 (13) in that order on laser-transparent substrate 1 (11), and then arranging semiconductor element (14) directly on resin film 2 (13) of laminate 1 (110). The laminate is then pressed using a pressure-bonding device (41) such as a vacuum laminator, wafer bonder, or press. Alternatively, as shown in FIG. 2, a semiconductor element temporary bonding substrate (130) is prepared in which semiconductor element (14) is temporarily bonded to another support (15) via temporary adhesive (16). The semiconductor element (14) on the temporary adhesive (16) and the resin film 2 (13) surface of laminate 1 (110) are then superimposed and pressed using the pressure-bonding device (41). The temporary adhesive (16) and support (15) are then removed, and laminate 2 (120) can be produced. Furthermore, as shown in FIG. 3 , a semiconductor element-mounted substrate (140) in which a semiconductor element (13) is directly formed on a crystal growth substrate (17) such as sapphire is superimposed on the laminate 1 (110) so that the surface of the semiconductor element (14) faces the surface of the resin film 2 (13) of the laminate 1 (110), and the substrate is pressure-bonded using the above-mentioned device (41). Thereafter, a laser (31) is irradiated from the crystal growth substrate (17) side to perform laser lift-off, whereby the semiconductor element (14) is removed from the crystal growth substrate (17) and placed on the laminate 110 side. The pressure applied when stacking the semiconductor elements can be optimized depending on the adhesive strength of the resin film 2 and is selected from a range of 0.05 MPa to 5.0 MPa. A pressure of 2.0 MPa or less is preferred to avoid damage to the semiconductor elements and to prevent them from being embedded in the resin film 2. Furthermore, when stacking the semiconductor elements, pressure can be applied while heating as needed. Heating reduces the elastic modulus of the resin film 2, allowing the semiconductor elements to be pressure-bonded at a lower pressure.

[0092] Furthermore, by providing alignment marks on the laminate in advance, it becomes easier to adjust the transfer position in subsequent operations.

[0093] Another method for producing the laminate 2 will now be described with reference to FIG. 4. A semiconductor substrate (18) in a state before being singulated is bonded to another support (15) via a temporary adhesive (16). A resin film 2 varnish is then applied to the semiconductor substrate (18) before being singulated, and the varnish is heated and cured to form a resin film 2 (13). A resin film 1 (12) is then formed on a laser-transparent substrate 1 (11). The surface of the resin film 1 (12) on the laser-transparent substrate 1 (11) and the surface of the resin film 2 (13) on the semiconductor substrate (18) are placed face-to-face and then pressure-bonded using the above-mentioned device (41). The support (15) and temporary adhesive (16) are peeled and removed, and the semiconductor substrate (18) is then singulated to form semiconductor elements (14), thereby producing a laminate 2 (120).

[0094] Next, a method for manufacturing a semiconductor device will be described.

[0095] The method for manufacturing a semiconductor device of the present invention is a method for manufacturing a semiconductor device using the laminate 2, and includes a step of placing the semiconductor element surface of the laminate 2 opposite to a substrate 2, and a subsequent step of irradiating laser light from the laser-transparent substrate 1 side of the laminate 2 to transfer the semiconductor element to the substrate 2.

[0096] The process of placing the semiconductor element surface of the laminate 2 and the substrate 2 opposite each other will be described with reference to the drawings.

[0097] A method for manufacturing a semiconductor device is shown in Figure 5. The semiconductor element surface refers to the surface of the laminate 2 (120) on which the semiconductor element (14) is located.

[0098] The semiconductor element surface of the laminate 2 (120) produced by the method described above is placed opposite the substrate 2 (21), and the substrate is fixed so that the laminate 2 (120) and the substrate 2 (21) are parallel. To prevent misalignment due to the weight of the semiconductor element (14) during transfer, the laminate 2 (120) and the substrate 2 (21) are placed facing each other with the laminate 2 (120) facing upward. The laminate 2 (120) and the substrate 2 (21) are placed at a fixed distance, and the distance between the semiconductor element surface and the substrate 2 can be selected depending on the size and thickness of the semiconductor element, and is selected in the range of several μm to several hundred μm.

[0099] Any substrate can be used for the substrate 2, such as a glass substrate, a resin substrate, a metal substrate, or a circuit board on which wiring has already been formed. An adhesive layer may also be provided to hold the semiconductor element after transfer. The adhesive layer can be made of an adhesive material such as polysiloxane resin, acrylic resin, polyester resin, ACF resin, conductive paste, or the resin film 2 of the present invention. The thickness of the adhesive layer is selected within a range of 0.5 μm to 100 μm depending on the size of the semiconductor element and the distance between the semiconductor element and the substrate 2.

[0100] Furthermore, for the purpose of transfer alignment, there may also be an alignment mark on the substrate 2 side.

[0101] Next, the process of transferring the semiconductor element to the substrate 2 by irradiating the laminate 2 with laser light from the side of the substrate 1 having laser transparency will be described with reference to the drawings.

[0102] An example of the transfer process is shown in Figure 6(a). In the laminate 2 (120) and substrate 2 (21) arranged as described above, laser light (31) is irradiated onto the semiconductor element (14) from the laser-transparent substrate 1 (11) side of the laminate 2 (120) through the laser-transparent substrate 1 (11). The type of laser light can be selected based on the wavelength used, including solid-state lasers such as YAG lasers, YVO4 lasers, fiber lasers, and semiconductor lasers, as well as gas lasers such as CO2 lasers, excimer lasers, and argon lasers. The beam shape of the irradiated laser light is not limited, and the laser light spot size can be smaller than the size of the semiconductor element. However, the laser light must be large enough to avoid hitting semiconductor elements adjacent to the semiconductor element to be transferred. Furthermore, if the laser light spot size is large enough to hit semiconductor elements adjacent to the semiconductor element to be irradiated, the laser (31) can also be irradiated through a photomask (51), as shown in Figure 6(b).

[0103] The laser beam can be selected at any energy density. From the viewpoint of the stability of the energy density of the laser beam, the energy density of the laser beam is set to 1 mJ / cm. 2 The above is preferable, and from the viewpoint of preventing damage to semiconductor elements and shortening the processing time, 1000 mJ / cm 2 More preferably, the energy density of the laser beam is 10 mJ / cm or less. 2 More than 500mJ / cm 2 The following is the result.

[0104] By using the laminate 2 of the present invention, transfer is possible even with low energy, and further, even when the energy density of the laser light is changed, the influence on positional accuracy, debris, and adhesive residue can be reduced. The energy density of the irradiated laser light may have output unevenness, and in order to reduce the influence of output unevenness on transferability, it is preferable that the laminate 2 has the same level of transferability regardless of the energy density of the laser light. The range of energy densities of laser light that has the same level of transferability is 30 mJ / cm. 2It is more preferable to have a margin of 50 μm / cm or more, and from the viewpoint of practicality, 2 The above is particularly preferred.

[0105] It is also possible to heat the substrate 2 when transferring the semiconductor elements. In particular, if an adhesive layer is formed on the substrate 2, the retention of the transferred semiconductor elements is improved. When heating the substrate 2, it is preferable to heat the substrate 2 to a temperature of 100°C or less, as this prevents warping of the substrate 2 due to heat and allows for transfer with high positional accuracy.

[0106] The transfer of the semiconductor elements is performed while adjusting the position to match the actual mounting location of the semiconductor elements in the semiconductor device to be fabricated. For example, when fabricating an LED substrate, the LED elements are transferred while shifting the pitch to match the LED pixel size and RGB arrangement. Next, the substrate 2 with the transferred LED elements and the circuit board are placed face to face and pressure-bonded to the circuit board, thereby fabricating a circuit board with mounted LED elements. When transfer is performed using the laminate of the present invention, transfer can be performed with high positional accuracy, so the semiconductor elements can be transferred without misalignment from the circuit on the board to which they will ultimately be mounted, reducing mounting defects caused by misalignment.

[0107] In the semiconductor device manufacturing method of the present invention, the laser light preferably has a wavelength of 248 nm, 266 nm, 308 nm, 355 nm, 532 nm, or 1064 nm, and it is particularly preferable to use a wavelength at which the resin film 1 has an absorbance of 0.4 or higher. Using these laser lights can reduce damage to semiconductor elements. The laser light more preferably has a wavelength of 248 nm, 266 nm, or 355 nm, allowing for accurate transfer of even minute semiconductor elements such as μLEDs. As laser light of 248 nm, 266 nm, 308 nm, 355 nm, 532 nm, or 1064 nm, excimer lasers, YAG lasers, and IR lasers are particularly preferred.

[0108] Furthermore, in the method for manufacturing a semiconductor device of the present invention, the substrate 2 is preferably a circuit substrate. If the substrate 2 is a circuit substrate, the substrate transferred by the above method can be directly fabricated into a semiconductor device. This eliminates concerns about misalignment due to handling of the substrate after transfer, and further improves positional accuracy. Known circuit substrates such as TFT substrates and printed wiring boards can be used.

[0109] The present invention will be specifically described below based on examples. [Example]

[0110] The present invention will be described below with reference to examples, but the present invention is not limited to these examples. First, the evaluation methods used in each example and comparative example will be described.

[0111] (1) Method for producing laminate A varnish for resin film 1 prepared by the method described below was applied using a spinner to a 4-inch glass substrate with a 0.5 mm thick alignment mark (Corning Eagle XG, absorbance at 355 nm: 0.01) or a 4-inch synthetic quartz substrate with a 0.5 mm thick alignment mark (Taiko Seisakusho, absorbance at 266 nm: 0.01), and the substrate was pre-baked on a hot plate at 120°C for 3 minutes, and then further heated and cured at a specified temperature for a specified time, thereby producing resin film 1 on the glass substrate or synthetic quartz substrate.

[0112] Furthermore, a varnish for resin film 2 prepared by the method described below was applied using the same spinner, pre-baked on a hot plate at 120°C for 3 minutes, and then heated and cured at a specified temperature for a specified time to produce a laminate 1 in which resin film 1 and resin film 2 were laminated in sequence on a glass substrate or a synthetic quartz substrate.

[0113] The thicknesses of the resin films 1 and 2 were confirmed by cutting the laminate and observing the cross section with a scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation).

[0114] Separately, a silicon wafer was polished on the back side to a thickness of 100 μm, which was then attached to a dicing tape (UDC-1025MC, manufactured by Denka Co., Ltd.) and processed to a size of 100 μm x 200 μm using a dicing machine (DAD300, manufactured by Disco Co., Ltd.) to produce dummy chips for semiconductor elements. The distance between chips was 150 μm, and the number of dummy chips per unit area was 1100 chips / cm. 2 It was.

[0115] The dicing tape was irradiated with UV light to reduce the adhesiveness of the dicing tape. The surrounding dummy chips were removed with tweezers, leaving 100 chips arranged in 10 columns and 10 rows. The dummy chips on the dicing tape were placed on the resin film 2 side of the laminate 1, with the chip surfaces facing each other. The dummy chips were then pressed onto the resin film 2 using a vacuum laminator. The dicing tape was then peeled off to produce laminate 2. The surfaces of the dummy chips stacked on the resin film 2 were visually observed with an optical microscope, and the number of chips that could be stacked on the resin film 2 and the number of chips that could be stacked without damage were counted. The results are shown in Tables 2 and 3.

[0116] (2) Measurement of absorbance of resin film 1 The varnish for resin film 1 was applied to a quartz substrate in the same manner as in (1) above, prebaked, and heat-cured to prepare a quartz substrate with resin film 1 for absorbance measurement. The film thickness was also measured in the same manner. The absorbance was continuously measured from 200 nm to 1100 nm using a UV-visible spectrophotometer (Hitachi, Ltd., U-2910). The values ​​at 248 nm, 266 nm, 308 nm, 355 nm, 532 nm, and 1064 nm were read, and the respective absorbances per μm were calculated using the following equation: Absorbance per μm = actual absorbance obtained in the measurement / measured film thickness (μm).

[0117] (3) Measurement of adhesive strength of the surface of resin film 2 opposite to the surface of resin film 1 (3)-1 Measurement of adhesive strength of the resin film 2 on the surface opposite to the resin film 1 side of the laminate 1 A Kapton film cut into a 1 cm x 9 cm strip was pressure-bonded to the surface of the resin film 2 of the laminate 1 prepared by the above-mentioned method, opposite to the resin film 1 side, using a vacuum laminator at 0.1 MPa and 25°C. The sample was placed in a tensile tester (Nidec-Shimpo Corporation, FGS-VC), and the pressure-bonded Kapton film was peeled off in the vertical direction at a constant speed of 2 mm / sec. The peel strength at this time was measured using a digital force gauge (Nidec-Shimpo Corporation, FGJN-5). The measurement was performed three times using different samples, and the average value was taken as the adhesive strength.

[0118] (3)-2 Measurement of adhesive strength of the surface of the resin film 2 in the laminate 2 opposite to the resin film 1 side Dicing tape (UDC-1025MC) was attached to the surface of a dummy chip laminated on the resin film 2 of the laminate 2 produced by the method described above, and the dummy chip was peeled off by peeling it off. Kapton film was pressed onto the surface of the resin film 2 from which the dummy chip had been peeled off in the same manner as in (3)-1, and the adhesive strength was measured in the same manner as in (3)-1.

[0119] (4) Measurement of indentation hardness H1 and H2 The indentation hardness H1 and H2 were measured using a nanoindenter (Triboindenter TI950, manufactured by Hysitron).

[0120] In the case of laminate 1, laminate 1 was cut into a size of 10 mm x 10 mm to prepare a measurement sample. In the case of laminate 2, the dummy chip was peeled off from the laminate in the same manner as in the measurement of the adhesive strength of resin film 2 described above in (3), to prepare a sample with resin film 2 exposed, and the sample was then cut into a size of 10 mm x 10 mm.

[0121] The prepared sample was fixed to a dedicated sample fixing stand using an adhesive (Aron Alpha Fast Acting Multi-Purpose, manufactured by Toagosei Co., Ltd.), and a Berkovich indenter (a triangular pyramidal diamond indenter) was used to press the sample from the surface of resin film 2 toward resin film 1, and then the indentation hardness H2 was measured using an indentation load / unload test in which the load was removed.

[0122] The indentation hardness H1 was measured after removing the semiconductor element from the laminate 2 using the method described above, and then removing the resin film 2 by dry etching to expose the surface of the resin film 1. Dry etching of the resin film 2 was performed using O2 gas in advance at a location different from the measurement location, and the etching rate of the resin film 2 was calculated. Based on the results, the etching time for the resin film 2 was determined, and etching was then performed. The components of the surface of the resin film were then analyzed using ATR-IR (BRUKER, INVENIO S), and removal of the resin film 2 was confirmed when the components of the resin film 2 could no longer be detected.

[0123] The samples from which the resin film 2 had been removed by the above method were similarly cut into 10 mm x 10 mm pieces, and the samples were indented from the surface of the resin film 1 toward the laser-transparent substrate 1, and then the indentation hardness H1 was measured by an indentation load / unload test in which the load was removed. The measurement conditions are as follows: [Measurement conditions] Measurement environment: 25±2℃, atmospheric air Measurement frequency: 100Hz Measurement method: Continuous stiffness measurement method. From the load-indentation depth diagram obtained, the indentation hardness H1 and the indentation hardness H2 were calculated using values ​​in the indentation region that was not affected by the underlying substrate.

[0124] (5) Film thickness measurement The laminate 2 was cut, and the cross section was observed with a scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation), and t1 (μm) and t2 (μm) were measured.

[0125] (6) Measurement of breaking elongation The varnishes for resin films 1 and 2 were applied to copper foil using a bar coater, prebaked on a hot plate at 120°C for 3 minutes, and then heat-cured at the temperatures and times shown in Table 2 below, producing a 10 μm-thick resin film 1 on the copper foil. The resulting copper foil laminated with resin films 1 and 2 was then completely etched with a ferric chloride solution to produce single films of resin film 1 and resin film 2. The resulting single films were cut into 1.5 cm wide, 2 cm long strips to prepare samples for elongation measurement. The samples were stretched at a room temperature of 23.0°C and a humidity of 45.0% RH at a tensile speed of 50 mm / min using a Tensilon RTM-100 (manufactured by Orientec Co., Ltd.). The elongation at break at room temperature of 23.0°C was measured using 10 strips per specimen, and the average of the top five points for each result was calculated.

[0126] (7) Measurement of thermal decomposition temperature A single film of the resin film 2 used in measuring elongation was heat-treated at 250°C for 30 minutes, and then approximately 15 mg was placed in a standard aluminum container and measured using a thermogravimetric analyzer (TGA-50, manufactured by Shimadzu Corporation). The measurement conditions were to hold the film at 120°C for 30 minutes, then raise the temperature to 500°C at a rate of 5°C / min. The temperature at which the weight decreased by 1% was read from the obtained weight loss curve, and this temperature was defined as the 1% weight loss temperature.

[0127] (8) Semiconductor chip transfer test (8)-1 Preparation of opposing substrate for transfer Polydimethylsiloxane was diluted with toluene to a 4-inch alkali-free glass substrate (Corning Eagle XG) with a 0.5 mm thickness and equipped with an alignment mark. The diluted solution was adjusted to a weight ratio of 1:9, and applied using a spinner. The solution was then heated and cured on a hot plate at 120°C for 3 minutes to form an adhesive layer on the glass substrate. The thickness of the adhesive layer after heat curing was measured using an optical film thickness meter (Dainippon Screen, Lambda Ace, refractive index = 1.543), and an opposing substrate with an adhesive layer thickness of 20 μm was prepared.

[0128] (8)-2 Transfer of semiconductor elements Next, a laser light source, laminate 2 prepared by the method described above, and an opposing substrate were arranged in this order. The surface of the laminate holding the dummy chip and the surface of the opposing substrate on which the adhesive layer was formed were held facing each other so that the distance between the dummy chip surface and the adhesive layer surface was 50 μm. The laminate and opposing substrate were aligned using their respective alignment marks. The spot size of the laser light was adjusted to a square shape of 120 μm x 220 μm using a slit, and the positions of the laser light source and laminate were adjusted so that one dummy chip was positioned in the center of the laser light spot, preventing the laser light from hitting adjacent dummy chips.

[0129] A dummy chip placed at the laser light irradiation position is irradiated with laser light of wavelengths 248 nm, 266 nm, 208 nm, 355 nm, 536 nm or 1064 nm at 150 mJ / cm 2 ~400mJ / cm 2 Between 50mJ / cm 2 The irradiation was carried out while changing the energy density step by step. At each energy density, a transfer test was carried out on three dummy chips.

[0130] (8)-3 Evaluation of transferability The opposing substrate was observed after irradiation with the laser light, and the number of dummy chips for which it was confirmed that three dummy chips had been transferred to substrate 2 was counted. The dummy chips transferred to the opposing substrate were also checked under a microscope, and at each laser light energy density, if no chips were damaged, it was evaluated as no chip damage, and if even one chip with a crack, chipping, or fracture was observed, it was evaluated as chip damage.

[0131] (8)-4 Evaluation of position accuracy The position of the semiconductor element on the opposing substrate after transfer was calculated from the alignment marks on the opposing substrate and compared with the position on the laminate 2. Of the three chips transferred at each energy density, the chip with the greatest positional misalignment was evaluated for positional accuracy as follows: If the misalignment was within the range of less than ±5 μm in the X-axis direction and less than ±5 μm in the Y-axis direction, the positional accuracy was evaluated as A; if the misalignment was within the range of ±10 μm or more in the X-axis direction or ±10 μm or more in the Y-axis direction, the positional accuracy was evaluated as C; and if the misalignment was within any range in between, the positional accuracy was evaluated as B.

[0132] (8)-5 Evaluation of adhesive residue After irradiation with the laser light, the transferred chips were observed under an optical microscope without being washed, and the area of ​​adhesive residue on the contact surface with resin film 2 of the dummy chip was confirmed for either resin film 1 or resin film 2. The average area of ​​adhesive residue on the contact surface with resin film 2 for chips that were successfully transferred at each energy density was calculated, assuming that the surface area of ​​the contact surface with resin film 2 per chip is 100%. As a result, when the average adhesive residue area was 0% or more but less than 1%, adhesive residue was rated A, when it was 1% or more but less than 30%, adhesive residue was rated B, and when it was 30% or more, adhesive residue was rated C.

[0133] (8)-6 Debris evaluation After laser irradiation, the opposing substrate was observed under an optical microscope without being cleaned, and foreign matter of 1 μm or larger observed on the surface of the adhesive layer around the transferred dummy chip was counted. The average number of chips that were successfully transferred at each energy density was calculated, and if there were fewer than 10 pieces, the debris was rated A, if there were 10 to 50 pieces, the debris was rated B, and if there were 50 pieces or more, the debris was rated C. If debris larger than 50 μm was included, it was rated C regardless of the number of pieces.

[0134] (8)-7 Evaluation of processing margin In the evaluations of (8)-3 to (8)-6 above, among the three dummy chips that were successfully transferred to the substrate 2, the evaluations of no chip damage, transfer position accuracy, adhesive residue, and debris were A or B. The energy density range where transfer was good was evaluated. 2 If it is above this, the processing margin is A, 50 mJ / cm 2 More than 100mJ / cm 2 If the processing margin is less than B, 50 mJ / cm 2 If it is less than this, the processing margin is set to C.

[0135] (9) Method for measuring the solid content of a resin solution Approximately 1 g of the resin solution produced by the method described below was weighed into an aluminum cup, placed on a hot plate at 120°C, and heated for 3 minutes, then heated to 250°C and heated for 30 minutes after reaching 250°C. The weight of the resin remaining after heating was measured, and the solid content was calculated using the following formula. Solid content (wt%) = weight of resin after heating (g) / weight of resin solution before heating (g) × 100.

[0136] The abbreviations for the acid dianhydrides, diamines, additives and solvents shown in the following Preparation Examples are as follows: PMDA: Pyromellitic anhydride (manufactured by Daicel Corporation) BPDA: 3,3',4,4'-biphenyltetracarboxylic anhydride (Mitsubishi Chemical Corporation) BTDA: 3,3',4,4'-benzophenonetetracarboxylic anhydride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) DIBOC: di-tert-butyl dicarbonate (Tokyo Chemical Industry Co., Ltd.) PA: Phthalic anhydride (Tokyo Chemical Industry Co., Ltd.) PDA: p-phenylenediamine (Tokyo Chemical Industry Co., Ltd.) BAHF: 4,4'-dihydroxy-3,3'-diaminophenylhexafluoropropane (manufactured by Merck Ltd.) APPS2: α,ω-bis(3-aminopropyl)polydimethylsiloxane (average molecular weight: 860, q=9 (average value)) (manufactured by Shin-Etsu Chemical Co., Ltd.) APPS3: α,ω-bis(3-aminopropyl)polydimethylsiloxane (average molecular weight: 1600, q=19 (average value)) (manufactured by Shin-Etsu Chemical Co., Ltd.) NMP: 2-methyl-1-pyrrolidone (Mitsubishi Chemical Corporation) DMIB: N,N-dimethylisobutyramide (Mitsubishi Chemical Corporation) CHN: Cyclohexanone (manufactured by Toyo Gosei Co., Ltd.) TPX1291: Carbon black (manufactured by CABOT) BYK21116: Polymer dispersant (manufactured by BYK-Chemie) JER871: Dimer acid modified epoxy resin (Mitsubishi Chemical Corporation) PETG: Pentaerythritol-based epoxy resin (manufactured by Showa Denko K.K.) 2E4MZ: 2-ethyl-4-methylimidazole (manufactured by Shikoku Chemicals Corporation) 100LM: A crosslinking agent having an alkoxymethyl group represented by the following structure (manufactured by Sanwa Chemical Co., Ltd.)

[0137] [ka]

[0138] Production Example 1 (Polymerization of Resin Contained in Resin Film 1) A reactor equipped with a thermometer, dry nitrogen inlet, a heating / cooling system using hot and cold water, and a stirrer was charged with 11.82 g (0.109 mol) of PDA and 195.8 g of DMIB and dissolved. A solution of 0.48 g (2.19 mmol) of DIBOC and 26.1 g of DMIB was added dropwise with stirring and stirred at 40 °C for 1 hour. Next, 12.87 g (0.437 mol) of BPDA and 13.05 g of DMIB were added and stirred at 60 °C for 30 minutes. Subsequently, 13.83 g (0.063 mol) of PMDA and 13.05 g of DMIB were added and stirred at 60 °C for 4 hours to obtain a polyimide precursor PAA-1 solution with a solids content of 13 wt%. The aromatic ring structure in PAA-1 constituted 99.5 mol% of the total monomer residues (100 mol%). PAA-1 is a resin having the structure of formula (2).

[0139] Production Example 2 (Polymerization of Resin Contained in Resin Film 1) A reactor equipped with a thermometer, dry nitrogen inlet, a heating / cooling system using hot and cold water, and a stirrer was charged with 127.5 g (0.150 mol) of APPS2 and 866 g of NMP at 40 °C and dissolved. 37.85 g (0.350 mol) of PDA and 113.5 g of NMP were then added and dissolved. Next, 73.56 g (0.250 mol) of BPDA and 95.06 g (0.295 mol) of BTDA were added along with 223.5 g of NMP. The reaction was allowed to proceed at 60 °C for 4 hours, yielding a polyimide precursor PAA-2 solution with a solids content of 25 wt%. The aromatic ring structure-containing monomer residues in PAA-2 accounted for 85 mol% of the total 100 mol% of the precursor monomer residues. PAA-2 is a resin having the structure of formula (2) and formula (5).

[0140] Production Example 3 (Polymerization of Resin Contained in Resin Film 2) A reactor equipped with a thermometer, dry nitrogen inlet, hot and cold water heating and cooling system, and a stirrer was charged with 344.0 g (0.40 mol) of APPS2, 37.50 g (0.025 mol) of APPS3, and 27.47 g (0.075 mol) of BAHF along with 481.4 g of CHN. After dissolving, 14.81 g (0.10 mol) of PA and 20.00 g of CHN were added and stirred at 60 °C for 15 minutes. Next, 97.61 g (0.45 mol) of PMDA and 20.00 g of CHN were added and stirred at 60 °C for 1 hour. The temperature was then raised to 145 °C and the reaction was continued for 4 hours, yielding a 50 wt% solids solution of polyimidesiloxane PIS-1. The flexible monomer residues in PIS-1 comprised 43 mol% of the total 100 mol% of the monomer residues. PIS-1 is a resin having the structure of formula (1) and formula (5).

[0141] Production Example 4 (Polymerization of Resin Contained in Resin Film 2) A reactor equipped with a thermometer, dry nitrogen inlet, hot and cold water heating and cooling system, and a stirrer was charged with 254.56 g (0.296 mol) of APPS2, 28.68 g (0.019 mol), 20.33 g (0.056 mol) of BAHF, and 310.56 g of CHN. After dissolving, 16.44 g (0.111 mol) of PA and 38.82 g of CHN were added and stirred at 60 °C for 15 minutes. Subsequently, 68.20 g (0.312 mol) of PMDA and 38.82 g of CHN were added and stirred at 60 °C for 1 hour. The temperature was then raised to 145 °C and the reaction was continued for 4 hours, yielding a 50 wt% solids solution of polyimidesiloxane PIS-2. The flexible monomer residues in PIS-2 comprised 40 mol% of the total monomer residues (100 mol%). PIS-2 is a resin having the structure of formula (1) and formula (5). Production Example 5 (Polymerization of Resin Contained in Resin Film 2) A reactor equipped with a thermometer, dry nitrogen inlet, a heating / cooling system using hot and cold water, and a stirrer was charged with 39.04 g (0.033 mol) of Elastomer 650P and 131.69 g of NMP at 40 °C and dissolved. To this was added 8.25 g (0.076 mol) of PDA and 16.42 g of NMP and dissolved. Next, 15.87 g (0.054 mol) of BPDA and 17.39 g (0.054 mol) of BTDA were added along with 16.42 g of NMP. The reaction was allowed to proceed at 60 °C for 4 hours, yielding a polyimide precursor PAA-3 solution with a solids content of 30 wt%. The aromatic ring structure in PAA-3 constituted 84.9 mol% of the total monomer residues (100 mol%). PAA-3 is a resin having the structure of formula (2) and formula (7).

[0142] Production Example 6 (Preparation of Carbon Black Dispersion Contained in Resin Film 1) A methyl methacrylate / methacrylic acid / styrene copolymer (30 / 40 / 30 weight ratio) was synthesized using the method described in Japanese Patent No. 3120476. Then, 40 parts by weight of glycidyl methacrylate was added. The mixture was reprecipitated with purified water, filtered, and dried to obtain an acrylic polymer (P-1) powder with an average molecular weight (Mw) of 40,000 and an acid value of 110 (mgKOH / g). 400 g of TPX1291 was added to a tank along with 187.5 g of a 40 wt% solution of acrylic resin (P-1) in propylene glycol monomethyl ether acetate, 62.5 g of a polymer dispersant (BYK21116; manufactured by BYK-Chemie), and 890 g of propylene glycol monoethyl ether acetate. The mixture was stirred for 1 hour using a homomixer (manufactured by Tokushu Kika Co., Ltd.) to obtain preliminary dispersion 1. Thereafter, preliminary dispersion 2 was supplied to an Ultra Apex Mill (manufactured by Kotobuki Industries Co., Ltd.) equipped with a centrifugal separator filled to 70% with 0.10 mmφ zirconia beads (manufactured by Toray Industries, Inc.), and dispersion was carried out for 2 hours at a rotation speed of 8 m / s to obtain carbon black pigment dispersion Bk-1 having a solids concentration of 25 wt % and a pigment / resin (weight ratio) of 80 / 20.

[0143] Examples 1 to 23, Comparative Examples 1 to 2 The resin solutions obtained in Production Examples 1 to 5 were mixed and stirred with the carbon black dispersion obtained in Production Example 6, additives, and solvents according to the details in Table 1 to prepare varnishes for Resin Film 1 and Resin Film 2. The varnishes were filtered through a PTFE filter with a pore size of 0.2 μm. Laminates were prepared using these varnishes according to the method described above. Details of the prepared laminates and the various evaluation results are summarized in Tables 2 to 5.

[0144] [Table 1]

[0145] [Table 2-1]

[0146] [Table 2-2]

[0147] [Table 3-1]

[0148] [Table 3-2]

[0149] [Table 4-1]

[0150] [Table 4-2]

[0151] [Table 5-1]

[0152] [Table 5-2] [Explanation of symbols]

[0153] 11 Laser-transparent substrate 1 12 Resin film 1 13 Resin film 2 14 Semiconductor elements 15 Support 16 Temporary adhesive 17 Crystal growth substrate 18 Semiconductor substrate 21 Substrate 2 31 Laser 41 Crimping device 51 Photomask 110 laminate 1 120 Laminate 2 130 Substrate to which semiconductor element is temporarily attached 140 Substrate with semiconductor element

Claims

1. A laminate in which a laser-transmitting substrate 1, a resin film 1, and a resin film 2 are laminated in this order, the resin film 1 has an absorbance of 0.4 or more and 5.0 or less at a wavelength of 200 to 1100 nm when converted into a film thickness of 1.0 μm; The laminate has an adhesive strength of 0.02 N / cm or more and 0.3 N / cm or less on the surface of the resin film 2 opposite to the resin film 1 side.

2. A laminate in which a laser-transmitting substrate 1, a resin film 1, a resin film 2, and a semiconductor element are laminated in this order, the resin film 1 has an absorbance of 0.4 or more and 5.0 or less at a wavelength of 200 to 1100 nm when converted into a film thickness of 1.0 μm; The laminate has an adhesive strength of 0.02 N / cm or more and 0.3 N / cm or less at the surface where the resin film 2 and the semiconductor element contact each other.

3. 3. The laminate according to claim 1, wherein the resin film 1 has an absorbance of 0.4 or more and 5.0 or less at a wavelength of 248 nm, 266 nm, 308 nm, 355 nm, 532 nm, or 1064 nm, calculated as a film thickness of 1.0 μm.

4. 4. The laminate according to claim 1, wherein the resin film 1 has an absorbance of 0.4 or more and 5.0 or less at a wavelength of 248 nm, 266 nm, or 355 nm when converted into a film thickness of 1.0 μm.

5. 5. The laminate according to claim 1, wherein an indentation hardness H2 measured by pressing from the resin film 2 side to the substrate 1 side is 2 MPa or more and 500 MPa or less, and satisfies H1 > H2, where H1 is an indentation hardness H1 measured by pressing from the resin film 1 side to the substrate 1 side with the resin film 2 removed from the laminate.

6. 6. The laminate according to claim 1, wherein, when the thickness of the resin film 1 is t1 (μm) and the thickness of the resin film 2 is t2 (μm), (t1 + t2) is 1.0 μm or more and 30 μm or less, and t1 / t2 is 0.1 or more and 5.0 or less.

7. The laminate according to any one of claims 1 to 6, wherein the resin film 1 has a breaking elongation of 2.0% or more and 30% or less.

8. 8. The laminate according to claim 1, wherein an indentation hardness H1 measured by indenting from the resin film 1 side to the substrate 1 side is 50 MPa or more and 1000 MPa or less.

9. 9. The laminate according to claim 1, wherein the resin film has a breaking elongation of 100% or more and 1000% or less.

10. The laminate according to any one of claims 1 to 9, wherein the resin film 1 contains one or more selected from the group consisting of a polyimide having a structure of formula (1), a polyimide precursor having a structure of formula (2), a polybenzoxazole having a structure of formula (3), a polybenzoxazole precursor having a structure of formula (4), and copolymers thereof. 【Chemistry 1】 (In formulas (1) to (4), R １ , R ３ , R ７ and R ９ each independently represents a tetravalent organic group having 6 to 40 carbon atoms; R ２ , R ４ , R ６ and R ８ R each independently represents a divalent organic group having 2 to 40 carbon atoms. ５ represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

11. The laminate according to any one of claims 1 to 10, wherein the resin contained in the resin film 2 has one or more structures selected from the group consisting of a dimethylsiloxane structure represented by formula (5), a diphenylsiloxane structure represented by formula (6), an alkylene glycol structure represented by formula (7), and an alkylene structure represented by formula (8). 【Chemistry 2】 (In formulas (5) to (8), R １０ ~R １３ each independently represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; l, m, and n each independently represent an integer of 4 to 40; p represents an integer of 10 to 40; and o represents an integer of 1 to 16.

12. The laminate according to any one of claims 1 to 11, wherein the resin contained in the resin film 2 is polyimide siloxane.

13. The laminate according to any one of claims 1 to 12, wherein the resin film (2) contains a crosslinking agent.

14. The laminate according to any one of claims 1 to 13, wherein the resin film 2 has a 1% weight loss temperature of 300°C or higher.

15. A method for manufacturing a semiconductor device using the laminate according to claim 2, comprising: a step of placing a semiconductor element surface of the laminate and a substrate 2 opposite each other; The method for manufacturing a semiconductor device further comprises a step of irradiating the laminate with laser light from the laser-transparent substrate 1 side to transfer the semiconductor element to the substrate 2.

16. 16. The method for manufacturing a semiconductor device according to claim 15, wherein the laser light has a wavelength of any one of 248 nm, 266 nm, 308 nm, 355 nm, 532 nm and 1064 nm.

17. 17. The method for manufacturing a semiconductor device according to claim 15, wherein the substrate is a circuit board.

Images