Temporary Fixation Composition

Abstract

To reduce air bubbles mixing in a spin coat step in production of electronic devices.SOLUTION: A temporary fixation composition containing the following (A)-(C) and characterized by a viscosity in a range of 500-10000 mPa s under atmospheric pressure at 23°C. measured by a rotary rheometer and a shear rate of 1 s-1. (A) A monofunctional (meth) acrylate in which a surface tension measured by a ds / de method by a pendant drop method at 23°C. is in the range of 20-30 mN / m (B) A polyfunctional (meth)acrylate in which the viscosity at 23°C. measured by a rotary rheometer and having a shear rate of 1 s-1 is 1000 mPa s or more under atmospheric pressure, or is solid at 23°C., or a molecular weight is 500 or more and the viscosity of 23°C measured by a rotary rheometer at a shear rate of 1 s-1 is 100 mPa s or more and less than 1000 mPa s under atmospheric pressure (C) Photoradical polymerization initiator.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a composition used for temporary fixation. [Background technology]

[0002] In the manufacture of electronic devices, wafer-type substrates with a thickness of several hundred micrometers are commonly used, obtained by using inorganic materials such as silicon as the substrate and applying processes such as insulating film formation, circuit formation, and thinning by grinding to the surface. However, since many substrates are made of brittle and easily broken materials, measures to prevent damage are necessary, especially during thinning by grinding. Conventionally, this measure involves applying a temporary fixing protective tape, which can be peeled off after the processing is completed, to the side opposite the surface to be ground (also called the back). This tape uses an organic resin film as its base material, and while it is flexible, its strength and heat resistance are insufficient, making it unsuitable for use in processes involving high temperatures.

[0003] Therefore, a system has been proposed that provides sufficient durability to the conditions of processes such as backside grinding and backside electrode formation by bonding an electronic device substrate to a support such as silicon or glass via an adhesive. What is important in this process is the adhesive layer used when bonding the substrate to the support. This adhesive must be able to bond the substrate to the support without any gaps, have sufficient durability to withstand subsequent processes, and finally allow the thinned wafer to be easily peeled off the support, i.e., to be temporarily fixed.

[0004] The processing of such wafers mainly involves spin coating, vacuum bonding and photocuring, thinning by grinding and polishing, high-temperature processing, laser stripping, and removal of temporary fixative.

[0005] In the spin coating process, in order to uniformly form a film of the temporary fixative on the wafer, it is required that the temporary fixative has a suitable viscosity and be a Newtonian fluid (or that its shear viscosity is independent of the shear rate).

[0006] In the vacuum bonding / UV curing process, it is required for the temporary fixing agent to be able to be cured by light irradiation such as ultraviolet light (UV) in a short time on a support such as glass, and to have little outgassing (low outgassing property).

[0007] In the thinning process by grinding and polishing, in order to avoid damage caused by the load of the grinding machine being locally applied to the substrate, an appropriate hardness is required for the temporary fixing agent to maintain flatness while preventing local sinking of the substrate while dispersing the load in the in-plane direction. Furthermore, the adhesive force with the support, an appropriate level of the elastic modulus for protecting the edge, and chemical resistance are also required.

[0008] In the high-temperature treatment process, heat resistance that can withstand long-term high-temperature treatment (for example, at 300 °C or higher for one hour or more) in a vacuum is required for the temporary fixing agent.

[0009] In the laser peeling process, it is required for the temporary fixing agent to be able to be peeled off at high speed by a laser such as a UV laser.

[0010] In the removal process, in addition to easy peelability that allows the substrate to be easily peeled off from the support, aggregating properties and easy cleaning properties for preventing adhesive residues from remaining on the substrate after peeling are required.

[0011] In view of such a background, for example, in Patent Document 1, a temporary fixing composition containing (A-1) a monofunctional (meth)acrylate having a side chain of an alkyl group with 18 or more carbon atoms and a Tg of the homopolymer of -100 °C to 60 °C, (A-2) a polyfunctional (meth)acrylate, (B) a polyisobutene homopolymer and / or a polyisobutene copolymer, and (C) a photo radical polymerization initiator is disclosed, and it is boasted that it is excellent in heat resistance, low outgassing property, and peelability.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0013] When applying a temporary fixing agent according to the prior art onto a wafer by spin coating, it has been reported that bubbles are generated in the temporary fixing agent and trapped as they are. Since bubbles have an adverse effect on physical properties, reduction thereof has been demanded.

Means for Solving the Problems

[0014] The inventor of the present invention has elucidated the mechanism of this bubble entrainment and conceived means for eliminating it. That is, the present invention can provide the following aspects.

[0015] Aspect 1. A temporary fixing composition containing the following (A) to (C) and having a viscosity of 500 to 10,000 mPa·s at 23°C and a shear rate of 1 s measured by a rotary rheometer under atmospheric pressure. -1 (A) A monofunctional (meth)acrylate having a surface tension measured by the ds / de method using the pendant drop method at 23°C in the range of 20 to 30 mN / m (B) Having a viscosity of 1000 mPa·s or more at 23°C and a shear rate of 1 s measured by a rotary rheometer under atmospheric pressure, or being solid at 23°C, or having a molecular weight of 500 or more and having a viscosity of 100 mPa·s or more and less than 1000 mPa·s at 23°C and a shear rate of 1 s measured by a rotary rheometer under atmospheric pressure -1 -1 A polyfunctional (meth)acrylate (C) A photo radical polymerization initiator

[0016] Aspect 2. (A) In the mass ratio of component (A) to component (B), the amount of component (A) is in the range of 5 to 65%. The temporary fixing composition according to Aspect 1.

[0017] Aspect 3. (A) The temporary fixation composition according to embodiment 1 or 2, wherein component (A) is an aliphatic monofunctional (meth)acrylate.

[0018] Appearance 4. The temporary fixation composition according to embodiment 3, wherein the aliphatic group of component (A) has 6 or more carbon atoms and 30 or fewer carbon atoms.

[0019] Appearance 5. (B) A temporary fixation composition according to any one of embodiments 1 to 4, wherein component (B) comprises an oligomer or polymer.

[0020] Appearance 6. A temporary fixing composition according to any one of embodiments 1 to 5, further containing (D) below. (D) UV absorber

[0021] Appearance 7. A cured body of the temporary fixing composition described in any one of embodiments 1 to 6.

[0022] Appearance 8. A cured body according to embodiment 7, wherein the temperature at which the 2% mass loss occurs is 300°C or higher under a nitrogen atmosphere.

[0023] Appearance 9. A method for manufacturing a substrate for electronic devices, The steps include: preparing a composition by mixing a monofunctional (meth)acrylate, a polyfunctional (meth)acrylate, and a photoradical polymerization initiator, wherein the viscosity at 23°C is in the range of 500 to 10000 mPa·s; The prepared composition is coated onto a silicon wafer by a spin coating method, and the surface of the coated composition is made flat with a height difference of 40 μm or less. The steps include: adhering a support to the silicon wafer so as to sandwich the coated composition; A manufacturing method that includes this.

[0024] Appearance 10. A temporary fixing adhesive comprising the temporary fixing composition described in any one of embodiments 1 to 6.

[0025] Appearance 11. An adhesive comprising a temporary fixing adhesive as described in embodiment 10 and a substrate to be bonded by the temporary fixing adhesive.

[0026] Appearance 12. A method for manufacturing a thin wafer using the temporary fixing adhesive described in Embodiment 10. [Effects of the Invention]

[0027] According to the present invention, a novel composition is obtained that can reduce the inclusion of air bubbles in the spin coating process during the manufacturing of electronic devices. [Modes for carrying out the invention]

[0028] In this specification, unless otherwise specified, numerical ranges include their upper and lower limits. In this specification, a monofunctional (meth)acrylate means a compound having one (meth)acryloyl group in one molecule. A polyfunctional (meth)acrylate means a compound having two or more (meth)acryloyl groups in one molecule. An n-functional (meth)acrylate means a compound having n (meth)acryloyl groups in one molecule. The polymerizable functional group in a polyfunctional (meth)acrylate may have only an acryloyl group, only a methacryloyl group, or both an acryloyl group and a methacryloyl group.

[0029] In embodiments of the present invention, a temporary fixing composition (also referred to as "temporary fixing agent") can be provided, comprising (A) a monofunctional (meth)acrylate having predetermined physical properties, (B) a polyfunctional (meth)acrylate having predetermined physical properties, and (C) a photoradical polymerization initiator, and having a predetermined viscosity as a whole. The inventors of the present invention came to the realization that in the spin-coating process of temporary fixing agents in the manufacturing process of electronic device substrates, the target substrate rotates, causing the temporary fixing agent on it to deform slightly due to centrifugal force, and the degree of this slight deformation affects whether or not air bubbles are incorporated.

[0030] In the spin coating process, it is known that centrifugal force causes a bulge (called an "edge bead") near the edge of the object. However, in the field of acrylate-based temporary fixatives consisting of a combination of monofunctional (meth)acrylate and polyfunctional (meth)acrylate, it was unknown what factors influenced the formation of this edge bead. Specifically, it was discovered that the edge bead becomes high if several conditions are not met, including the surface tension of the monofunctional (meth)acrylate, the viscosity of the polyfunctional (meth)acrylate, and the viscosity of the mixture. Furthermore, it was found that if the height of the edge bead is 40 μm or less, air bubbles are less likely to form when the wafer and support are bonded together. Based on these discoveries, the problem presented by the present invention was solved.

[0031] In this specification, the viscosity of the entire composition is measured at 23°C (at atmospheric pressure) using a rotary rheometer, with a shear rate of 1 s. -1 The viscosity is in the range of 500 to 10000 mPa·s. Preferably, the viscosity is 500 to 8000 mPa·s, and more preferably 500 to 5000 mPa·s. If the overall viscosity of the composition is less than 500 mPa·s, the coatability is poor and it is not practical. If the overall viscosity of the composition exceeds 10000 mPa·s, the viscosity is too high and it is not suitable for spin coating. Furthermore, in this specification, the viscosity of component (B), described later, is measured in the same manner as above.

[0032] The monofunctional (meth)acrylate component (A) contained in this composition is characterized by having a surface tension in the range of 20 to 30 mN / m, as measured by the pendant drop method ds / de at 23°C. Although hypothetical, it is presumed that if the surface tension of component (A), which plays a role in forming a relatively flexible skeleton in the composition, falls within a narrow, specific range, it will be less susceptible to deformation by centrifugal force due to its interaction with component (B).

[0033] The ds / de method is a technique for calculating the surface tension γ using the following formula, by measuring the maximum diameter (equatorial diameter) de of a pendant drop (suspended drop method) and the diameter ds of the pendant drop at a position de away from the lowest point of the pendant drop. γ = ρg(de) 2 (1 / H) In the formula, ρ is density, g is acceleration due to gravity, and 1 / H is a correction term derived from ds / de. The ds / de method is well known, for example, from the following literature. https: / / www.scas.co.jp / technical-informations / technical-news / pdf / tn142.pdf

[0034] (A) The type of component can be selected based on the ds / de method. If component (A) contains two or more monofunctional (meth)acrylates, it can be determined by measuring the surface tension of the mixture. The surface tension of the entire composition can also be measured in the same way as for component (A) alone, and is preferably in the range of 28 to 33 mN / m at 23°C. It is hypothetical that there is a direct correlation between the surface tension of the composition and the height of the edge bead, which will be discussed later.

[0035] Component (A) is preferably an aliphatic monofunctional (meth)acrylate. The number of carbon atoms in the aliphatic group may be between 6 and 30, and more preferably between 8 and 20. Although hypothetical, it is presumed that a component (A) with moderately strong hydrophobicity makes it easier to obtain the surface tension effect described above. Furthermore, monofunctional (meth)acrylates with strong polarity, such as acryloylmorpholine, are generally considered unsuitable because they result in excessively high surface tension.

[0036] In the mass ratio of component (A) to component (B), the amount of component (A) is preferably in the range of 5 to 65%, more preferably 5 to 60%, and even more preferably 10 to 50%.

[0037] The polyfunctional (meth)acrylate component (B) contained in this composition has a shear rate of 1 s at 23°C as measured by a rotary rheometer. -1 The viscosity at which it is found is 1000 mPa·s or more under atmospheric pressure, or it is a solid at 23°C, or its molecular weight is 500 or more and the shear rate at 23°C measured by a rotational rheometer is 1 s².-1 The viscosity at 23°C is characterized by being 100 mPa·s or more and less than 1000 mPa·s (preferably 120 mPa·s or more and less than 1000 mPa·s) under atmospheric pressure. Note that the above statement, "...the viscosity at 23°C is 1000 mPa·s or more under atmospheric pressure, or it is a solid at 23°C," essentially means that the latter is describing the upper limit of viscosity (i.e., being a solid can also be interpreted as having very high viscosity). Therefore, please note that the above statement, "...the viscosity at 23°C is 1000 mPa·s or more under atmospheric pressure," is not technically unclear simply because no upper limit is specified.

[0038] While we do not wish to be bound by any particular theory, it is hypothesized that combining component (B), which has such viscosity or molecular weight or is solid at room temperature, with component (A) above will cause the alkyl group of component (A) to face outwards and come to the surface, thereby reducing edge bead formation. The type of component (B) can be selected based on a viscosity measurement method. If component (B) contains two or more polyfunctional (meth)acrylates, the type can be determined by measuring the viscosity of the mixture.

[0039] (B) Component may be a monomer, or it may contain an oligomer or polymer.

[0040] The photoradical polymerization initiator, which is component (C) of this composition, is a substance that can initiate radical polymerization of components (A) and (B) upon light irradiation, and is, for example, a compound whose molecule is cleaved and splits into two or more radicals upon irradiation with ultraviolet light or visible light (e.g., wavelength 350 nm to 700 nm, preferably 365 nm to 500 nm, more preferably 385 nm to 450 nm). Examples of photoradical polymerization initiators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis(η 5Examples include -2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)-butan-1-one, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyl oxime, and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyl oxime). Component (C) may contain one or more of these, or a combination of two or more.

[0041] Preferably, component (C) may include an acylphosphine oxide compound. Preferred acylphosphine oxide compounds include one or more compounds from the group consisting of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide. As a photoradical polymerization initiator, it is preferable that it is highly sensitive, has photobleaching properties and therefore exhibits excellent deep curing properties, and that the absorption wavelength range for generating radicals extends to a relatively long wavelength range. In the preferred compounds described above, the absorption wavelength range is in the range up to a wavelength of approximately 440 nm, which is a large difference from the absorption wavelength range of the UV absorber used in the UV laser peeling step described later. In other words, the degree of UV curing inhibition by the UV absorber is small, and radical polymerization can be started with longer wavelength light. Therefore, even in the presence of a UV absorber, the effect of initiating radical polymerization at a relatively high speed and efficiently and curing can be obtained.

[0042] In a preferred embodiment, a photo radical polymerization initiator can be selected from absorbance. Specifically, when dissolved at a concentration of 0.1% by mass in a solvent having no maximum absorption in the wavelength range of 300 nm to 500 nm (for example, acetonitrile, toluene, etc.), the absorbance at a wavelength of 365 nm is 0.5 or more, the absorbance at a wavelength of 385 nm is 0.5 or more, and the absorbance at a wavelength of 405 nm is 0.5 or more. One or more photo radical polymerization initiators can be selected from one or more compounds that satisfy any one or more of these conditions. Examples of compounds that satisfy such conditions include 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetoxyoxime), which has an absorbance of 0.5 or more at a wavelength of 365 nm when dissolved at a concentration of 0.1% by mass with respect to acetonitrile as a solvent; 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyloxime, which has an absorbance of 0.5 or more at wavelengths of 365 nm and 385 nm; bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide, which have an absorbance of 0.5 or more at wavelengths of 365 nm, 385 nm, and 405 nm.

[0043] Also, from the viewpoint of achieving both curability by a photo radical polymerization initiator and UV laser peeling, bis(η 5 -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, which has an absorption wavelength region in the range of 400 to 500 nm, can also be used as a photo radical polymerization initiator.

[0044] (C) As a photoradical polymerization initiator, one or more compounds selected from acylphosphine oxide compounds, titanocene compounds, or α-aminoalkylphenone compounds are preferred in terms of reaction rate, heat resistance after curing, low outgassing, and absorption characteristics in a region different from both the wavelength of the UV laser used in the UV laser peeling process described later and the absorption wavelength region of the UV absorber used in the UV laser peeling process. In addition, as a photoradical polymerization initiator for a resin composition used for temporary fixing to prevent damage from bonding the substrate to the support substrate to the heating process, not for the layer corresponding to the UV laser peeling process among the temporary fixing compositions having the structure described later, oxime ester compounds may also be selected in addition to the above.

[0045] Examples of acylphosphine oxide compounds include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide. Among these, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is particularly preferred.

[0046] Examples of titanocene compounds include bis(η) 5 An example is -2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium.

[0047] Examples of α-aminoalkylphenone compounds include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one and 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)-butan-1-one.

[0048] Examples of oxime ester compounds include 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-O-benzoyl oxime and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyl oxime). Among these, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyl oxime) is preferred.

[0049] (C) The amount of photoradical polymerization initiator used is preferably 0.01 to 5 parts by mass, and more preferably 0.1 to 1 part by mass, per 100 parts by mass of the total of components (A) and (B), in terms of reaction rate, heat resistance after curing, and low outgassing. If component (C) is 0.01 parts by mass or more, sufficient curability can be obtained, and if it is 5 parts by mass or less, the effect of low outgassing and heat resistance is not easily impaired can be obtained.

[0050] This composition may contain a UV absorber as component (D). A UV absorber is a compound whose molecules are broken down and decomposed and vaporized by irradiation with ultraviolet or visible light lasers, and which causes the adhesive strength between the temporary fixative and the support substrate (or support) to be lost when this decomposition and vaporization occurs at the interface between the support substrate (or support) and the temporary fixative, thereby maintaining the adhesive strength between the temporary fixative and the support substrate (or support) until immediately before the peeling process.

[0051] (D) As for the UV absorber, one or more selected from benzotriazole compounds, benzophenone compounds, and hydroxyphenyltriazine compounds are preferred in terms of the degree of overlap with the UV laser wavelength in the UV absorption wavelength region, UV absorption characteristics at the same wavelength, low outgassing, and heat resistance.

[0052] As benzotriazole compounds, one or more selected from the group consisting of 2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2,2'-methylenebis[6-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol], 2-(2H-benzotriazole-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, and 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole and 2-(2'-hydroxy-5'-methacryloyloxyethylphenyl)-2H-benzotriazole are particularly preferred in terms of compatibility with resin components, UV absorption properties, low outgassing properties, and heat resistance.

[0053] As hydroxyphenyltriazine compounds, one or more selected from the group consisting of 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine, and 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine are particularly preferred in terms of compatibility with components (A) and (B), UV absorption properties, low outgassing, and heat resistance.

[0054] As benzophenone compounds, one or more selected from 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-diacryoyloxybenzophenone, and hydroxybenzophenone compounds are particularly preferred in terms of compatibility with components (A) and (B), UV absorption properties, low outgassing, and heat resistance.

[0055] In a preferred embodiment for use in a UV laser peeling process, the most preferred UV absorber is one or more selected from the group consisting of 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine, or 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol]. These have excellent compatibility with component (A), high melting points, and relatively low vapor pressures under temperature conditions of approximately 300°C or less, allowing for selection within a wide range of usage amounts, and contributing to the reduction of outgassing from the temporary fixing composition after curing under these temperature conditions.

[0056] (D) Most preferably, the following UV absorbers selected based on their UV transmittance can be used as UV absorbers. (D) Having such UV transmittance in component (D) provides the effect of appropriately controlling the curing and peeling of the composition.

[0057] When a UV absorber is dissolved at a concentration of 0.002% by mass in a solvent that does not have maximum absorption at wavelengths of 290 to 410 nm, it is preferable that the transmittance at a wavelength of 355 nm with a path length of 1 cm is 50% or less, and the transmittance at wavelengths of 385 to 420 nm is higher than 50%. More preferably, the transmittance at a wavelength of 355 nm is 40% or less, and the transmittance at wavelengths of 385 to 420 nm is 60% or more.

[0058] From the viewpoint of transmittance under the above conditions, preferred (D) UV absorbers include, for example, the following: 2-(2'-hydroxy-5'-methacryloyloxyethylphenyl)-2H-benzotriazole (RUVA-93, Otsuka Chemical Co., Ltd., molecular weight 323.0), 2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (Tinuvin 900, BASF; Adeka Stab LA-24, Adeka Corporation; EVERSORB 76 / EVERSORB 234, Everlight Chemical Co., Ltd., molecular weight 447), 2-(2H-benzotriazole-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (Tinuvin 928, BASF; EVERSORB 89 / 89FD, molecular weight 442), 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (BASF Tinuvin 405, molecular weight 584), 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine (BASF Tinuvin 460, molecular weight 630).

[0059] In this specification, the UV transmittance of the cured material is a value obtained by reflectance spectroscopy. Specifically, the transmittance is obtained using a reflectance spectrometer (V-650, manufactured by JASCO Corporation) with a cured material film approximately 50 μm thick, prepared by sandwiching it between sheets of PET resin, under the following conditions.

[0060] Cell length: 10mm Metering mode: T (Transmittance) Measurement range: 450-200nm Data acquisition interval: 1nm UV / vis bandwidth: 2.0nm Response: medium Scanning speed: 40 nm / min Light source switching: 340nm Light source: D2 / WI Filter switching: Step Correction: Baseline

[0061] The amount of UV absorber component (D) is preferably 0.01 to 5 parts by mass, and more preferably 0.5 to 2.5 parts by mass, per 100 parts by mass of the total of components (A) and (B). If it is 0.01 parts by mass or more, a sufficient UV laser peeling speed can be obtained, and if it is 5 parts by mass or less, the effect of low outgassing and heat resistance is not easily impaired can be obtained.

[0062] In this specification, the weight-average molecular weight is a value on a standard polystyrene basis measured by gel permeation chromatography (GPC). Specifically, the weight-average molecular weight is determined under the following conditions, using tetrahydrofuran as the solvent, a GPC system (SC-8010, manufactured by Tosoh Corporation), and a calibration curve created using commercially available standard polystyrene.

[0063] Flow rate: 1.0ml / min Set temperature: 40℃ Column configuration: One 6.0mm ID x 4.0cm column of "TSK guardcolumn MP (xL)" manufactured by Tosoh Corporation, and two 7.8mm ID x 30.0cm columns of "TSK-GELMULTIPOREHXL-M" manufactured by Tosoh Corporation (16,000 theoretical plates), for a total of three columns (32,000 theoretical plates in total). Sample injection volume: 100 μl (sample solution concentration 1 mg / ml) Fluid delivery pressure: 39 kg / cm² 2 Detector: RI detector (differential refractive index detector)

[0064] In one embodiment of the present invention, a cured body of the above-described composition can also be provided. Such curing may be performed using a light source described later. When the cured body is in the form of a cured film with a thickness of 50 μm, it is preferable that one or more of the following conditions are met, and more preferably that all of them are met. The following conditions can be met, for example, by using a UV absorber. The light transmittance of the cured film must be 70% or higher in the wavelength range of 395 nm or more of the light source used for curing. The light transmittance of the cured film must be 20% or more in the wavelength range of the light source used for curing, specifically in the wavelength range of 385 nm to less than 395 nm. • The light transmittance of the cured film at the wavelength of the UV laser used for UV laser peeling (355 nm) must be 1% or less. By satisfying these conditions, it is possible to achieve both a sufficiently high curing speed and a UV laser peeling speed for practical use. Furthermore, in addition to achieving both a sufficiently high curing speed and a UV laser peeling speed, it is possible to reduce the rate of mass loss under heating conditions after curing (or reduce the amount of outgassing under high temperature vacuum). A temporary fixative with such characteristics can be suitably used in processes that include high temperature vacuum processes such as ion implantation, annealing, and electrode formation by sputtering, particularly in the back surface process after thinning.

[0065] This composition can be used as a temporary fixing resin composition, a temporary fixing adhesive, an adhesive sheet, or a temporary fixing adhesive for the manufacture of electronic devices. In this specification, temporary fixing compositions, temporary fixing resin compositions, and temporary fixing adhesives may be collectively referred to as temporary fixing agents.

[0066] When using this composition to bond a substrate to be processed with an optically transparent support substrate (or support), the energy amount in the visible light or ultraviolet region (wavelength or center wavelength preferably 350-405 nm, more preferably 365-405 nm, and most preferably 385-405 nm) should be 1-20000 mJ / cm². 2 It is preferable to irradiate in such a way that the energy amount is 1 mJ / cm². 2 At this level, sufficient adhesion can be achieved, up to 20,000 mJ / cm². 2 The following conditions result in superior productivity, reduced decomposition products from photoradical polymerization initiators, and suppressed outgassing: 1000-10000 mJ / cm². This is optimal in terms of productivity, adhesion, low outgassing, and ease of removal. 2 It is preferable that this be the case.

[0067] The substrates to be bonded by this composition are not particularly limited, but at least one of the substrates is preferably a transparent substrate that transmits light. Examples of transparent substrates include inorganic substrates such as quartz, glass, silica, calcium fluoride, and magnesium fluoride, and organic substrates such as plastics. Among these, inorganic substrates are preferred because they are versatile and provide a great effect. Among inorganic substrates, one or more selected from glass and silica are preferred.

[0068] This composition may be photocurable, and the resulting cured product has excellent heat resistance and release properties. In one embodiment, the cured product of the composition of the present invention exhibits low outgassing even when exposed to high temperatures, making it suitable for bonding, sealing, and coating various optical components, optical devices, and electronic components. The composition of the present invention is suitable for applications requiring a wide range of durability, such as solvent resistance, heat resistance, and adhesiveness, particularly for semiconductor manufacturing processes.

[0069] The cured product of this composition can be used in processes over a wide temperature range from room temperature to high temperatures. The heating temperature during the process is preferably 350°C or lower, more preferably 300°C or lower, and most preferably 250°C or lower. In a preferred embodiment, the temperature at which the heating mass reduction rate of the cured product becomes 2% may be 250°C or higher. Adhesives bonded with this composition have high shear adhesion and can withstand thinning processes, etc., and can be easily peeled off after heating processes such as insulating film formation. When used at high temperatures, the cured product of this composition can be used in processes at high temperatures, for example, preferably 200°C or higher, more preferably 250°C or higher.

[0070] In one embodiment, an adhesive is provided in which a substrate is bonded using the composition as an adhesive. This adhesive can be peeled off by applying an external force. For example, it can be peeled off by inserting a blade, sheet, or wire into the joint. Alternatively, it can be peeled off by irradiating the entire surface of the adhesive with a UV laser or IR laser from the optically transparent substrate side.

[0071] <Manufacturing method for thin wafers> In one embodiment, a method for manufacturing a thin wafer can also be provided. This manufacturing method is characterized by using the above-mentioned temporary fixing composition or temporary fixing adhesive (hereinafter sometimes simply referred to as adhesive or temporary fixing agent) as the adhesive layer between the wafer having semiconductor circuits and the support. This method for manufacturing a thin wafer has the following steps (a) to (e).

[0072] [Process (a)] Step (a) is a step in which, when joining the circuit-forming surface of a wafer having a circuit-forming surface on its front surface and a non-circuit-forming surface on its back surface to a support via an adhesive, an adhesive is applied to the support or the circuit-equipped wafer by a spin-coating method, and the two supports or circuit-equipped wafers are bonded together under vacuum.

[0073] A wafer having a circuit-forming surface and a non-circuit-forming surface is a wafer in which one surface is a circuit-forming surface and the other surface is a non-circuit-forming surface. The wafer to which the present invention can be applied is usually a semiconductor wafer. Examples of such semiconductor wafers include not only silicon wafers, but also gallium nitride wafers, lithium tantalate wafers, lithium niobate wafers, silicon carbide wafers, germanium wafers, gallium-arsenide wafers, gallium-phosphorus wafers, gallium-arsenide-aluminum wafers, and the like. The thickness of the wafer is not particularly limited, but is preferably 600 to 800 μm, and more preferably 625 to 775 μm. As a support, for example, a transparent substrate that transmits light is used.

[0074] [Step (b)] Step (b) is a step of photocuring the adhesive. After the wafer processed body (laminated substrate) is formed, the energy amount is 1 to 20,000 mJ / cm² in the visible light or ultraviolet region (the wavelength or central wavelength is preferably 350 to 405 nm, more preferably 365 to 405 nm, and most preferably 385 to 405 nm). 2 It is preferable to irradiate in such a way that the energy amount is 1 mJ / cm². 2 At this level, sufficient adhesion can be achieved, up to 20,000 mJ / cm².2 The following parameters result in superior productivity, reduced decomposition products from photoradical polymerization initiators, and suppressed outgassing: 1000-10000 mJ / cm². This is optimal in terms of productivity, adhesion, low outgassing, and ease of removal. 2 This is preferable.

[0075] For curing the composition, blacklights, UV-LEDs, and visible light-LEDs can be used as light sources, and for example, the following light sources can be used. As for blacklights, lights containing components with a wavelength of 385 nm or more are preferably used, regardless of their central wavelength. When a wavelength range is described in this specification, whether or not a component falls within that range shall be determined by whether or not its central wavelength falls within that range. • Black light (center wavelength 365nm, illuminance 10mW / cm²) 2 (Manufactured by Toyo Adtec Co., Ltd., TUV-8271) ·UV-LED (wavelength 385±5nm, illuminance 350mW / cm 2 (Conditions: Working distance from the tip of the mirror unit is 20mm), HOYA H-4MLH200-V2-1S19 + specially designed mirror unit) ·UV-LED (wavelength 395±5nm, illuminance 375mW / cm 2 (Conditions: Working distance from the tip of the mirror unit is 20mm), HOYA H-4MLH200-V3-1S19 + specially designed mirror unit) ·UV-LED (wavelength 405±5nm, illuminance 400mW / cm 2 (Conditions: Working distance from the tip of the mirror unit is 20mm), HOYA H-4MLH200-V4-1S19 + specially designed mirror unit) ·UV-LED (center wavelength 405nm, illuminance 10mW / cm 2 (CCS Corporation HLDL-120V0-NWPSC) ·Visible light-LED (wavelength 451±5nm, illuminance 550mW / cm 2 (Conditions: Work distance 10mm from the tip of the irradiation unit, CCS HLDL-155VL450-PSC) ·Visible light-LED (wavelength 492±5nm, illuminance 400mW / cm 2 (Conditions: Working distance from the tip of the irradiation unit 10 mm, CCS HLDL-155BG-PSC)

[0076] In a preferred embodiment, a UV-LED or visible light-LED, which requires less integrated light (and thus less irradiation time), may be used as the light source, rather than a black light, which generally has a broad irradiation wavelength and therefore tends to have a large integrated light amount and a long irradiation time. That is, by using an LED light source with a narrow irradiation wavelength band, temporary fixing can be performed in a short time, resulting in the effect of shortening the time required for the manufacturing process.

[0077] [Process (c)] Step (c) is a step of grinding and / or polishing the non-circuit-formed surface of the wafer bonded to the support, that is, a step of grinding the back side of the wafer processed body obtained by bonding in step (a) to reduce the thickness of the wafer. The thickness of the thinned wafer is preferably 10 to 300 μm, and more preferably 30 to 100 μm. There are no particular restrictions on the method of grinding / polishing the back side of the wafer, and known grinding / polishing methods can be used. Grinding is preferably performed while cooling by applying water to the wafer and grinding wheel (such as a grinding wheel with a diamond blade).

[0078] [Step (d)] Step (d) is a process of processing the non-circuit-formed surface of a wafer processed body that has been ground / polished on the non-circuit-formed surface, that is, the non-circuit-formed surface of a wafer processed body that has been thinned by back grinding / polishing. This step includes various processes used at the wafer level. Examples include electrode formation, metal wiring formation, protective film formation, etc. More specifically, conventionally known processes include metal sputtering for the formation of electrodes, wet etching for etching the metal sputtering layer, application of resist to serve as a mask for metal wiring formation, exposure and development for pattern formation, peeling of resist, dry etching, metal plating formation, silicon etching for TSV formation, and oxide film formation on the silicon surface.

[0079] [Step (e)] Step (e) is a delamination step. This step involves delaminating the wafer processed in step (d) from the wafer processing body. For example, after various processes have been applied to a thinned wafer, this step involves delaminating the wafer from the wafer processing body before dicing. In this case, dicing tape can be attached to the thinned and processed surface in advance. This delamination step is generally carried out under relatively low temperature conditions, from room temperature to about 60°C. As this delamination step, any of the known UV laser delamination steps, IR laser delamination steps, or mechanical delamination steps can be employed.

[0080] The UV laser delamination process involves irradiating the entire surface of a wafer processing body with a UV laser, for example, by scanning it tangentially from the optically transparent support side edge of the wafer processing body in a linear, back-and-forth motion, thereby decomposing and delaminating the adhesive layer using the energy of the laser. Such delamination processes are described, for example, in Japanese Patent Publication No. 2019-501790 and Japanese Patent Publication No. 2016-500918.

[0081] The IR laser peeling process involves irradiating the entire surface of a wafer processing body with an IR laser, for example, by scanning it tangentially from the optically transparent support-side edge of the wafer processing body in a linear, reciprocating motion. The adhesive layer is heated and decomposed by the energy of the laser, causing it to peel off. Such a peeling process is described, for example, in Japanese Patent Publication No. 4565804. To carry out this IR laser peeling process, a photothermal conversion layer (for example, 3M's LTHC; Light-To-Heat-Conversion release coating) that absorbs IR laser light and converts it into heat may be provided between the temporary fixing agent layer and the glass support. When using 3M's LTHC, for example, the LTHC is spin-coated onto the glass support and cured. The temporary fixing agent layer can then be spin-coated onto the wafer and bonded to the glass support on which the LTHC layer has been formed, and UV cured. A method for carrying out the IR laser peeling process using 3M's LTHC is described, for example, in the same Japanese Patent Publication No. 4565804.

[0082] A mechanical delamination process is a delamination process that includes, for example, inserting a blade into the interface edge of the wafer processed body to cause a crack between the wafer and the support, fixing the wafer processed body horizontally with the wafer facing downwards, and then applying upward stress to the upper support and / or the blade after the blade is inserted to propagate the crack and delaminate the wafer and support. Such delamination processes are described, for example, in Japanese Patent No. 6377956 and Japanese Patent Application Publication No. 2016-106404.

[0083] Any of these peeling methods can be used to peel off this composition. In this case, it is preferable to fix one of the wafer or support of the wafer processed body horizontally, insert a blade or swell the outer periphery of the adhesive layer with a solvent (for example, an aliphatic or aromatic hydrocarbon solvent such as pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, or mesitylene) to initiate peeling, and then lift the other side from the horizontal at a certain angle. These peeling methods are usually carried out at room temperature, but it is also preferable to heat them to an upper limit of about 90°C. When using a laser, it is preferable to use a YAG laser or a YVO4 laser.

[0084] In the case of a mechanical peeling process, the process of peeling the wafer that has undergone the above process (e) from the support is further: (f) A step of adhering dicing tape to the wafer surface of the processed wafer, (g) A step of vacuum adsorbing the dicing tape surface onto the adsorption surface, (h) A step of peeling the support from the processed wafer at a temperature range of 10 to 100°C on the adsorption surface, It is preferable to include this. In this way, the support can be easily peeled off from the processed wafer, and the subsequent dicing process can be easily carried out.

[0085] Furthermore, if the peeling is done with a UV laser or IR laser, the manufacturing method may be further, for example (i) A step of placing / securing the processed wafer with the optically transparent support side facing upwards in a horizontal location, preferably via dicing tape, (j) A step of irradiating the entire surface of the wafer by scanning the laser from the support side of the processed wafer, It is preferable to include this. In this way, the support can be easily peeled off from the processed wafer, and the subsequent dicing process can be easily carried out.

[0086] Furthermore, following the step of peeling the wafer processed in step (e) from the support using a UV laser or IR laser, (k) A step to remove the temporary fixative remaining on the surface of the wafer. It is necessary to carry out the following. Methods for removing the temporary fixative include a method in which, with the thinned surface vacuum-adhered to the adsorption surface, an adhesive tape such as dicing tape is applied to the entire surface of the other side where the temporary fixative remains, and the temporary fixative is peeled off together with the tape; and a method in which the wafer is immersed in a solvent (for example, an aliphatic or aromatic hydrocarbon solvent such as pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, mesitylene, etc.) to swell the adhesive layer and peel it off. Of these methods, the tape peeling method is preferred in terms of the number of steps and the time required.

[0087] After the temporary fixing agent is removed, the wafer can proceed to the next process without cleaning the surface. If cleaning is required, (l) A step of cleaning the wafer, from which the support and temporary fixative have been removed, with the circuit formation surface facing upwards, using a solvent (for example, an aliphatic or aromatic hydrocarbon solvent such as pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, mesitylene, etc.). It is preferable to do so.

[0088] In step (k), some adhesive (temporary fixative) may remain on the circuit formation surface of the wafer after the temporary fixative has been removed. Furthermore, although it is preferable to clean and reuse the detached support, adhesive residue may also be adhering to the surface of this support. Methods for removing this adhesive residue include immersion in a solvent (for example, aliphatic or aromatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, and mesitylene) to cause swelling and subsequent detachment.

[0089] In one embodiment, various methods can be employed to cure the above composition to obtain a cured product, as described below.

[0090] As a first method, it is possible to obtain a single-layer cured body by curing a layer consisting of a temporary fixing composition containing the above-mentioned components.

[0091] A second method involves preparing a first layer consisting of a temporary fixing composition containing at least components (A) to (C) and not the UV absorber component (D), and a second layer consisting of a temporary fixing composition containing at least components (A) to (D), and curing them to obtain a cured body having an integrated single layer or multiple layers. In this cured body, it is preferable that the concentration distribution of the components differs with respect to its thickness, or that the concentration distribution of the components differs between the upper and lower surfaces with respect to the thickness of the cured body. The difference in the concentration distribution of the components can be confirmed by quantitatively measuring the UV transmittance on both sides of the cured body using the reflectance measurement spectroscopy method described above. This method provides the effect of achieving optimal curing by combining layers with different light transmittances. Furthermore, a black light or UV-LED can be used as a light source for the curing described above (the same applies to the method described below). An example of a black light is the TUV-8271 manufactured by Toyo Adtec Co., Ltd. (center wavelength 365 nm, illuminance 10 mW / cm²). 2 ) are some examples. Also, as for UV-LEDs, there is the HOYA Corporation H-4MLH200-V2-1S19 + specially designed mirror unit (wavelength 385±5nm, illuminance 350mW / cm²).2 Conditions: Scan pitch from the tip of the mirror unit is 20mm), HOYA Corporation H-4MLH200-V3-1S19 + specially designed mirror unit (wavelength 395±5nm, illuminance 375mW / cm²) 2 Conditions: Working distance from the tip of the mirror unit is 20 mm. HOYA Corporation H-4MLH200-V4-1S19 + specially designed mirror unit (wavelength 405 ± 5 nm, illuminance 400 mW / cm²) 2 Examples of conditions include: working distance of 20mm from the tip of the mirror unit.

[0092] As a third method, a multilayer cured body may be obtained by placing a layer of a commercially available LTHC agent (photothermal converter) on top of a layer consisting of a temporary fixing composition containing at least components (A) to (C), and then curing it. This provides the advantage of easily obtaining a cured body.

[0093] The cured material obtained by the method described above can be combined with an adherend to provide a structural body.

[0094] Various examples can be given for the manufacturing method of the structure described above. For example, the first manufacturing method may include the steps of applying a first temporary fixing composition containing at least components (A) to (C) but not component (D) onto a wafer and partially curing it; applying a second temporary fixing composition containing at least components (A) to (D) onto the partially cured temporary fixing composition; and further placing a transparent substrate on the applied second temporary fixing composition and photocuring it.

[0095] Furthermore, a second method for manufacturing the structure may include the steps of: applying a first temporary fixing composition containing at least components (A) to (C) but not component (D) onto a wafer and partially curing it as necessary; applying a second temporary fixing composition containing at least components (A) to (D) onto a transparent substrate and partially curing it as necessary; and bringing the sides of the wafer and the transparent substrate on which the temporary fixing compositions are applied into close contact, and then bonding them by photocuring.

[0096] In addition to the temporary fixing composition described above, the same composition used in the temporary fixing composition of the present invention can also be used as a raw material for a photothermal conversion (LTHC) layer that absorbs IR laser light and converts it into heat, as described in Japanese Patent Publication No. 4565804. By adding this composition as a component of the photothermal conversion (LTHC) layer, its heat resistance can be improved.

[0097] In one embodiment, a method for manufacturing a semiconductor wafer can be provided, comprising the steps of: applying a temporary fixing composition to a semiconductor wafer substrate and / or a support member to bond the semiconductor wafer substrate and the support member; curing the temporary fixing adhesive by irradiating it with light having a wavelength of 350 to 700 nm (preferably 365 to 500 nm, more preferably 385 to 450 nm) to obtain an adhesive body; and irradiating the adhesive body with laser light with a wavelength of less than 385 nm (preferably laser light with a wavelength of 200 nm or more and less than 385 nm) to peel off the semiconductor wafer substrate. This manufacturing method has the advantages of being simple, having a short cycle time, as both the curing and peeling steps are performed at room temperature, there is no need to heat or cool the components, and generally there is no need to use solvents.

[0098] Furthermore, the cured temporary fixing adhesive may form a single layer within the adhesive body. This allows for simplification of the process and reduction of cycle time.

[0099] In preferred embodiments, by including both the photoradical polymerization initiator of component (C) and the UV absorber of component (D) in the composition, it is possible to achieve both a fast curing rate and a fast peeling rate, even in a single-layer temporary fixing adhesive. Furthermore, it is possible to significantly reduce the amount of uncured UV-curable monomer components remaining in the cured material when the temporary fixing adhesive is UV-cured, thereby improving the heat resistance of the cured material and reducing volatile matter under a nitrogen atmosphere. That is, for example, it is possible to raise the 2% heat loss temperature in the Tg / DTA measurement of the cured material. Temporary fixing adhesives with high heat resistance and reduced volatile matter under a nitrogen atmosphere are extremely useful for recent semiconductor manufacturing processes. Preferably, the cured material may have a 2% mass loss temperature of 300°C or higher, preferably 320°C or higher, and more preferably 326°C or higher under a nitrogen atmosphere.

[0100] In one embodiment, a method for manufacturing a substrate for electronic devices can be provided. This manufacturing method may include the steps of: mixing a monofunctional (meth)acrylate, a polyfunctional (meth)acrylate, and a photoradical polymerization initiator to prepare a composition having a viscosity in the range of 500 to 10000 mPa·s at 23°C; coating the prepared composition onto a silicon wafer by a spin coating method so that the surface of the coated composition is flat with a height difference of 40 μm or less; and adhering a support to the silicon wafer so as to sandwich the coated composition. In this specification, the flatness of the composition surface is measured after coating by a spin coater and curing under the conditions described in the examples later. [Examples]

[0101] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited thereto.

[0102] Unless otherwise specified, experiments were conducted at 23°C and 50% humidity. Curable resin compositions (hereinafter sometimes referred to as liquid resin compositions) with the compositions shown in the table below (units are parts by mass) were prepared and evaluated. The following compounds were selected as components.

[0103] [Table 1]

[0104] [Table 2]

[0105] (composition) (A) The following components were used. The surface tension was measured at 23°C using the ds / de method with an "OCA20" instrument manufactured by Eiko Seiki Co., Ltd. The surface tension of the entire composition was also measured in the same manner. LA: Lauryl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., "LA", surface tension 29.3 mN / m) NOAA: n-octyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., surface tension 27.5 mN / m) INAA: Isononyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., surface tension 27.5 mN / m) ISTA: Isostearyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., surface tension 26.3 mN / m) ACMO: Acryloylmorpholine (ACMO, manufactured by KJ Chemicals, surface tension 44.6 mN / m)

[0106] (B) The following components were used. The viscosity values ​​or indication of solid state are for 23°C. HX-620: Caprolactone-modified hydroxypivalate neopentyl glycol diacrylate (manufactured by Nippon Kayaku Co., Ltd., "Kayarad HX-620", m+n≈4, (average) molecular weight 768, viscosity 290 mPa·s) HX-220: Caprolactone-modified hydroxypivalate neopentyl glycol diacrylate (manufactured by Nippon Kayaku Co., Ltd., "Kayarad HX-220", m+n≈2, (average) molecular weight 541, viscosity 120 mPa·s) A-BPEF-2: 9,9-Bis[4-(2-hydroxyethoxy)phenyl]ful orange acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd. as "NK Ester A-BPEF-2", molecular weight 546, viscosity is high beyond the detection limit, judged to be over 1000 mPa·s) RA-341: Polyfunctional methacrylate polymer (ART CURE RA-341 manufactured by Negami Kogyo Co., Ltd., weight-average molecular weight of the core polymer is approximately 70,000, and its viscosity is high, exceeding the measurement limit, and judged to be over 1000 mPa·s). A-BPE-2: Ethoxylated bisphenol A diacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd. as "NK Ester A-BPE-2", R=-CH2CH2O-, m=n=1, molecular weight 422, solid at 23°C in the structural formula below)

[0107] [ka] RC100C: An acrylate polymer having acryloyl groups at both ends (Kaneka Corporation's "Kaneka XMAP RC100C," with the following structural formula, (weight average) molecular weight 24000, high viscosity exceeding the detection limit, judged to have a viscosity of over 1000 mPa·s).

[0108] [ka]

[0109] The following components were used as other components for comparative examples. Tetrax 6T: Polyisobutylene (ENEOS Corporation's "Tetrax Grade 6T", viscosity-average molecular weight 60,000) A-DCP: Tricyclodecanedimethanol diacrylate ("NK Ester A-DCP" manufactured by Shin-Nakamura Chemical Industry Co., Ltd., molecular weight 304, viscosity 160 mPa·s) DCP: Tricyclodecanedimethanol dimethacrylate ("NK Ester DCP" manufactured by Shin-Nakamura Chemical Industry Co., Ltd., molecular weight 332, viscosity 130 mPa·s)

[0110] The following was used as component (C): Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (BASF "Irgacure 819")

[0111] The following was used as component (D): 2,4-Bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine (BASF's "Tinuvin 460") Hydroxyphenyltriazine-based UV absorber (BASF's "Tinuvin 479") 2-(2'-hydroxy-5'-methacryloyloxyethylphenyl)-2H-benzotriazole (RUVA-93, manufactured by Otsuka Chemical Co., Ltd.)

[0112] (Preparation of liquid sample) The materials were heated and mixed at 80°C to obtain a homogeneous mixture. The viscosity of each component and the overall composition was measured using an Anton-Paar MCR302 rotary rheometer with a CP50-2 cone plate at a temperature of 23°C and a shear rate of 1 s. -1 The value was measured as such. In addition, when measuring the viscosity of component (B) and the polyfunctional (meth)acrylate that is its comparative example, if the viscosity was too high for sufficient measurement with the rotary rheometer under the above measurement conditions, it was determined that the viscosity was clearly above 1000 mPa·s (estimated high viscosity of over 100,000 mPa·s).

[0113] (Measurement of 2% mass loss temperature) The liquid resin composition, homogenized by the above heating and mixing process, is sandwiched between PET films and spread out to a thickness of 70 μm, with an integrated light intensity of 5000 mJ / cm². 2 Cured samples were prepared by curing under the following conditions. Curing was performed using a UV-LED (center wavelength 405 nm, illuminance 100 mW / cm²).2 A wafer UV irradiator (MUVBA-0.4×0.6×0.2-0010) manufactured by ITEC Systems Co., Ltd. was used.

[0114] A 10 mg sample of the hardened material was weighed and heated from room temperature to 600°C at a heating rate of 10°C / min under a nitrogen gas flow rate of 70 ml / min using a Netsch Japan differential thermal and thermomass simultaneous measurement device "STA-2500". The hardened material was then weighed. The heating mass loss rate (2% mass loss temperature) under a nitrogen atmosphere was calculated.

[0115] (Evaluation of vacuum heat resistance) A 4-inch sample was prepared by bonding a 4-inch silicon wafer (10 cm in diameter x 525 μm thick) and a 4-inch glass wafer (10 cm in diameter x 0.7 mm thick) using the prepared liquid resin composition. During bonding, the thickness of the resin composition was adjusted by adding 0.1% by mass of Unitika glass beads (product name SPL-70, average particle size 70 μm) to a temporary fixing agent and mixing it. After bonding, the LED integrated light intensity was 5000 mJ / cm². 2 (Center wavelength 405nm, illuminance 100mW / cm 2 A bonded sample was prepared by curing under the following conditions: UV-LED (center wavelength 405nm, illuminance 100mW / cm²). 2 A wafer UV irradiator (MUVBA-0.4×0.6×0.2-0010) manufactured by ITEC Systems Co., Ltd. was used. The vacuum heat resistance of the obtained bonded samples was evaluated. Furthermore, the vacuum heat resistance of the obtained bonded samples was evaluated as described below.

[0116] Each bonded sample was placed in a vacuum hot plate chamber and heated for 1 hour under conditions of 300°C and 20 Pa. After that, the circumferential edge of the silicon wafer was visually observed and evaluated according to the following criteria. Excellent: The edges were not peeled off at all. Good: The length of the peeled area at the edge was less than 5 mm from the edge. Acceptable: The length of the peeled area at the edge was 5 mm or more but less than 10 mm from the edge. Unacceptable: The length of the peeled area at the edge was 10 mm or more from the edge.

[0117] (Evaluation of laser peelability) The bonded 4-inch sample prepared as described above was irradiated with a UV laser over a 210 mm square area fixed around the test specimen, scanning the entire surface of the specimen from the glass support side. The UV laser irradiation conditions are shown below. A Keyence "MD-U1020C" UV laser was used. Irradiation was performed under the following conditions: output 2.5W, frequency 40kHz, beam diameter 72μm, scan pitch 150μm, and scan speed 6m / sec. The delamination properties after irradiation were evaluated according to the definition below. A glass support that is not sticky and can be easily peeled off the temporary fixative by hand is rated as "Excellent". A "good" condition is one where some adhesiveness remains, but the glass support can be peeled off the temporary fixative by hand. Products where the glass support cannot be peeled off the temporary fixative by hand are considered "unacceptable".

[0118] (Evaluation of edge bead height) 6.5-7.5 g of the prepared resin composition was applied to an 8-inch Si wafer using a spin coater (Mikasa MS-A300), followed by low-speed rotation (50 rpm x 15 sec), and then the liquid was uniformly distributed by high-speed rotation under the following conditions: The top surface was moved into a glass chamber, the chamber was replaced with a nitrogen atmosphere, and the integrated LED light intensity was 8100 mJ / cm². 2 (Center wavelength 405nm, illuminance 45mW / cm 2 The bead was cured under the following conditions. The thickest part of the edge and the part more than 2 cm inside the edge were measured, and the difference was defined as the edge bead height. High-speed rotation conditions Rotation time: 15 seconds Rotation speed: N rpm (The rotation speed at which the thickness reaches 74-76 μm when the coating time is 15 seconds, using the viscosity value and the following formula) Application amount: 6.5-7.5g calculation formula h = h0 / {1 + t × (4ω)}2 h0 2 / 3ν)} 1 / 2 h: film thickness [mm], h0: initial film thickness [mm], ω: rotation speed [rad / sec], t: Time [sec], ν: Kinematic viscosity [mm 2 / sec] Rotation speed ω = πN / 30 ω: rotational speed [rad / sec], rotational speed [rpm] kinematic viscosity ν = μ / ρ ν: kinematic viscosity [m 2 / sec], μ: Viscosity [Pa s], ρ: Density [kg / m 3 ] Initial film thickness h0 = {w / (s × ρ)} × 10 h0: Initial film thickness [mm], w: Coating amount [g], s: Wafer area [cm²] 2 ], ρ: density [g / cm 3 ]

[0119] From the results above, in all of the compositions according to the examples of the present invention, the edge bead height was kept to 40 μm or less, and both laser peelability and heat resistance were good. On the other hand, Comparative Examples 1 and 2, which did not contain component (A), had high edge beads and could not prevent the incorporation of air bubbles. Comparative Examples 3 and 5, which did not meet the surface tension conditions of component (A), also had high edge beads. Comparative Example 4, which did not contain component (B), had poor laser peelability and was not suitable for practical use.

Claims

1. The following (A) to (C) are present, and the temperature measured by a rotary rheometer is 23°C and the shear rate is 1 s. -1 A temporary fixing composition characterized by having a viscosity in the range of 500 to 10,000 mPa·s under atmospheric pressure, and a surface tension measured by the pendant drop method ds / de method at 23°C in the range of 28 to 33 mN / m. (A) One or more monofunctional (meth)acrylates whose surface tension, measured by the pendant drop method ds / de at 23°C, is in the range of 20 to 30 mN / m. (B) Measurement using a rotary rheometer at 23°C and a shear rate of 1 s -1 The viscosity at which it is measured is 1000 mPa·s or more at atmospheric pressure, or it is solid at 23°C, or its molecular weight is 500 or more and the shear rate at 23°C and measured by a rotational rheometer is 1 s. -1 One or more polyfunctional (meth)acrylates having a viscosity of 100 mPa·s or more and less than 1000 mPa·s at atmospheric pressure. (C) Photoradical polymerization initiator

2. In the total of component (A) and component (B), the amount of component (A) is in the range of 5 to 65% by mass. The temporary fixing composition according to claim 1.

3. (A) The temporary fixation composition according to claim 1 or 2, wherein component (A) is an aliphatic monofunctional (meth)acrylate.

4. The temporary fixation composition according to claim 3, wherein the aliphatic group of component (A) has 6 or more carbon atoms and 30 or less carbon atoms.

5. (B) The temporary fixation composition according to claim 1 or 2, wherein component (B) comprises an oligomer or polymer.

6. The temporary fixing composition according to claim 1 or 2, further comprising (D) below. (D) UV absorber

7. A cured body of the temporary fixing composition according to claim 1 or 2.

8. The cured body according to claim 7, wherein the temperature at which the 2% mass reduction occurs is 300°C or higher under a nitrogen atmosphere.

9. A temporary fixing adhesive comprising the temporary fixing composition according to claim 1 or 2.

10. An adhesive comprising the temporary fixing adhesive described in Claim 9 and a substrate to be bonded by the temporary fixing adhesive.

11. A method for manufacturing a thin wafer using the temporary fixing adhesive described in Claim 9.

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