Manufacturing method of electronic component

Abstract

To provide a manufacturing method of an electronic component that can reduce damage to an electronic component and easily peel off a support even when subjected to heat treatment or treatment that generates heat.SOLUTION: A manufacturing method of an electronic component includes a support fixing step of fixing an electronic component to a support via a polyimide temporary fixing material, a treatment step of subjecting the electronic component fixed to the support to heat treatment or a treatment that generates heat, and a support peeling step of peeling the support from the electronic component by irradiating with a laser beam from the support side.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing an electronic component. [Background technology]

[0002] During processing of electronic components such as semiconductors, in order to facilitate the handling of the electronic components and prevent them from being damaged, the electronic components are fixed to a support via a temporary fixing material made of a pressure-sensitive adhesive composition, or a tape-shaped temporary fixing material having a pressure-sensitive adhesive layer is attached to the electronic components to protect them. For example, when a thick-film wafer cut from a high-purity silicon single crystal or the like is ground to a predetermined thickness to form a thin-film wafer, the thick-film wafer is adhered to a support via a temporary fixing material.

[0003] A temporary fixing material used for temporarily fixing electronic components in this way is required to have high adhesiveness capable of firmly fixing the electronic components during the processing step, and also to be able to peel off the electronic components without damaging them after the processing step is completed (hereinafter, also referred to as "high adhesion and easy peeling"). As a means for achieving high adhesion and easy peeling, for example, Patent Document 1 discloses an adhesive sheet using an adhesive in which a polyfunctional monomer or oligomer having a radiation-polymerizable functional group is bonded to the side chain or main chain of the polymer. By utilizing the fact that the polymer has a radiation-polymerizable functional group and is cured by exposure to ultraviolet light, the adhesive strength is reduced by exposure to ultraviolet light during peeling, allowing peeling without leaving any adhesive residue. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-32946 Summary of the Invention [Problem to be solved by the invention]

[0005] The electronic component fixed to the support via the temporary fixing material is processed, and then the support is peeled off and the electronic component is taken out from the temporary fixing material. Conventionally, when peeling off the support, a mechanical peel or gas peeling has been performed by making the temporary fixing material contain a gas generating agent and generating gas from the gas generating agent by light irradiation or the like. However, when mechanical peeling is performed after a heat treatment or a treatment involving heat generation is performed as a processing treatment of the electronic component, the electronic component may not be easily peeled off and may be damaged. In addition, in gas peeling, it is necessary to increase the amount of gas generated to make it easy to peel off, but in that case, the heat resistance of the temporary fixing material may be impaired. In addition, when generating gas from a gas generating agent by light irradiation, the temporary fixing material must be sufficiently light-transmitting, which is a problem in that the design freedom of the temporary fixing material is narrowed.

[0006] The present invention aims to provide a method for manufacturing electronic components that reduces damage to the electronic components and allows the support to be easily peeled off, even when the electronic components are subjected to a heat treatment or a treatment involving heat generation. [Means for solving the problem]

[0007] Disclosure 1 relates to a method for manufacturing an electronic component, the method including a support fixing step of fixing an electronic component to a support via a polyimide-based temporary fixing material, a treatment step of subjecting the electronic component fixed to the support to a heat treatment or a treatment involving heat generation, and a support peeling step of irradiating a laser beam from the support side to peel the support from the electronic component. Disclosure 2 relates to a method for producing an electronic component according to Disclosure 1, in which the polyimide-based temporary fixing material has photocuring properties, and includes a photocuring step of irradiating light to cure the polyimide-based temporary fixing material after the support fixing step and before the treatment step. The present disclosure 3 is a manufacturing method for an electronic component according to the present disclosure 1, in which the polyimide-based temporary fixing material has thermosetting properties, and the method includes a heat curing step of heating and curing the polyimide-based temporary fixing material after the support fixing step and before the treatment step. The present disclosure 4 is the method for producing an electronic component according to the present disclosure 1, 2, or 3, wherein the wavelength of the laser light is 200 nm or more and 550 nm or less. In the present disclosure 5, the irradiation intensity of the laser light is 50 mJ / cm 2 More than 2000mJ / cm 2 The following is a method for producing an electronic device according to Disclosure 1, 2, 3 or 4. The present disclosure 6 is the method for producing an electronic device according to the present disclosure 1, 2, 3, 4, or 5, wherein the laser light is a CW laser. The present disclosure 7 is the method for producing an electronic component according to the present disclosure 1, 2, 3, 4, or 5, wherein the laser light is a pulsed laser. The present disclosure 8 is the method for producing an electronic component according to the present disclosure 7, wherein the pulse width of the laser light is 100 nsec or less. A ninth aspect of the present disclosure is the method for producing an electronic component according to the first, second, third, fourth, fifth, sixth, seventh or eighth aspect of the present disclosure, in which the laser light is irradiated so as to scan the polyimide-based temporary fixing material. A tenth aspect of the present disclosure is a method for producing an electronic device according to the first, second, third, fourth, fifth, sixth, seventh, eighth, or nineth aspect of the present disclosure, wherein the distribution of intensity in the irradiation shape of the laser light is a Gaussian waveform. The present disclosure 11 is a method for producing an electronic device according to the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein the intensity distribution in the irradiation shape of the laser light is flattened. The present disclosure 12 is a method for producing an electronic component according to the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, wherein the irradiation shape of the laser light is a rectangle. The present disclosure 13 is a method for producing an electronic device according to the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, in which ventilation is performed when irradiating the laser light. The present disclosure 14 is the method for producing an electronic component according to the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, wherein the polyimide-based temporary fixing material has an absorbance of 0.1 or more at a wavelength of 308 nm. The present disclosure 15 is a method for producing an electronic part according to the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14, wherein the polyimide-based temporary fixing material has a 5% weight loss temperature of a cured product of 350° C. or higher. Disclosure 16 is the method for producing an electronic part according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15, wherein the polyimide-based temporary fixing material contains a resin having an imide skeleton in a repeating unit of the main chain. Disclosure 17 is a method for producing an electronic device according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16, wherein the resin having the imide skeleton in a repeating unit of the main chain has a constitutional unit represented by the following formula (1). Disclosure 18 is a method for producing an electronic component according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 17, which contains a compound having a maleimide group. Disclosure 19 is a method for producing an electronic device according to Disclosure 18, wherein the compound having a maleimide group is a bismaleimide compound or a compound having a maleimide group and an imide skeleton in a repeating unit of a main chain.

[0008] [ka]

[0009] In formula (1), P 1 represents an aromatic group, and Q 1 represents a substituted or unsubstituted linear, branched or cyclic aliphatic group. The present invention will be described in detail below.

[0010] The present inventors have investigated laser peeling in which a laser beam is irradiated from the support side when peeling a support from an electronic component, and have found that even when a heat treatment or a treatment involving heat generation is performed, damage to the electronic component can be reduced and the support can be easily peeled off, which has led to the completion of the present invention.

[0011] The method for producing an electronic component of the present invention includes a support fixing step of fixing an electronic component to a support via a polyimide-based temporary fixing material.

[0012] The polyimide-based temporary fixing material preferably has an absorbance of 0.1 or more at the wavelength of the irradiated laser light described below. By having the absorbance of 0.1 or more, even if the irradiated laser light has a relatively low energy, the polyimide-based temporary fixing material can be more easily peeled off from the support. More specifically, the absorbance at at least one wavelength selected from the group consisting of 532 nm, 355 nm, or 308 nm is preferably 0.1 or more, and the absorbance at at least one wavelength selected from the group consisting of 355 nm or 308 nm is more preferably 0.1 or more. The more preferable lower limit of the absorbance at the wavelength of 308 nm is 0.2, and the more preferable lower limit of the absorbance at the wavelength of 355 nm is 0.2. There is no particular upper limit to the absorbance at the wavelength of the irradiated laser light. The absorbance of the polyimide-based temporary fixing material at a wavelength of 308 nm can be measured using a spectrophotometer. Examples of the spectrophotometer include U-3900 (manufactured by Hitachi High-Tech Science Corporation). The optical path length at this time is the thickness of the polyimide-based temporary fixing material.

[0013] The polyimide-based temporary fixing material has a 5% weight loss temperature of preferably 350° C. or higher. When the polyimide-based temporary fixing material has a 5% weight loss temperature of 350° C. or higher, the resulting polyimide-based temporary fixing material has better heat resistance. The polyimide-based temporary fixing material has a more preferable lower limit of 5% weight loss temperature of 380° C. and a further more preferable lower limit of 400° C. Further, there is no particular preferred upper limit to the 5% weight loss temperature of the polyimide-based temporary fixing material, but the substantial upper limit is about 600° C. When the temporary fixing material has a curing property as described below, it is preferable that the 5% weight loss temperature of the cured product of the temporary fixing material is in the above range. The 5% weight loss temperature of the polyimide-based temporary fixing material can be measured by a thermogravimetric and differential thermal analyzer. Specifically, it can be measured by the following method. That is, first, when the polyimide-based temporary fixing material has a curing property, the temporary fixing material is cured. When the polyimide-based temporary fixing material has a photocuring property, the temporary fixing material is irradiated with light having a wavelength of 365 nm and an irradiation intensity of 70 mW / cm. 2 The polyimide-based temporary fixing material is cured by irradiating it with ultraviolet light for 300 seconds. If the temporary fixing material has thermosetting properties, the polyimide-based temporary fixing material is cured by heating it in an oven at 150°C for 10 minutes. After curing the temporary fixing material as necessary, the obtained sample is weighed in an aluminum pan. Next, the aluminum pan is set in a thermogravimetric and differential thermal simultaneous measurement device, and when the temperature is increased from 30°C to 500°C at a heating rate of 10°C / min under a nitrogen atmosphere, the temperature at which the weight of the polyimide-based temporary fixing material decreases by 5% compared to before the temperature increase can be obtained as the 5% weight loss temperature. As the thermogravimetric and differential thermal simultaneous measurement device, STA7200RV (manufactured by Hitachi High-Tech Science Corporation) can be used.

[0014] The polyimide-based temporary fixing material preferably contains a resin having an imide skeleton in the repeating unit of the main chain. The resin having the imide skeleton in the repeating unit of the main chain has excellent heat resistance due to the imide skeleton, and the main chain is unlikely to decompose even when subjected to high-temperature processing at 300°C or higher. Therefore, by containing the resin having the imide skeleton in the repeating unit of the main chain, the obtained polyimide-based temporary fixing material can suppress the occurrence of voids and lifting between the support during high-temperature processing, and can prevent increased adhesion to the adherend and the occurrence of adhesive residue when peeled off from the adherend.

[0015] The resin having an imide skeleton in the repeating unit of the main chain preferably has a constitutional unit represented by the above formula (1).

[0016] In the above formula (1), P 1 is preferably an aromatic group having 5 to 50 carbon atoms. 1is an aromatic group having 5 to 50 carbon atoms, the resulting polyimide-based temporary fixing material has excellent heat resistance. That is, the occurrence of voids and lifting between the support and the material during high-temperature processing can be further suppressed, and the occurrence of increased adhesion to the adherend and the occurrence of adhesive residue when peeled off from the adherend can be further prevented.

[0017] In the above formula (1), Q 1 is preferably a substituted or unsubstituted linear, branched or cyclic aliphatic group having 2 to 100 carbon atoms. 1 is a substituted or unsubstituted linear, branched or cyclic aliphatic group having from 2 to 100 carbon atoms, the resulting polyimide-based temporary fixing material has better light transmittance. In addition, the resulting polyimide-based temporary fixing material has better flexibility, can exhibit high conformability to an adherend having irregularities, and can be more easily peeled off. Also, the above Q 1 is preferably an aliphatic group derived from a diamine compound. In particular, from the viewpoints of light transparency, flexibility, and compatibility with solvents and other components of the resin having the imide skeleton in the main chain repeating unit, Q is preferably an aliphatic group derived from a diamine compound. 1 is preferably an aliphatic group derived from dimer diamine. The dimer diamine is a diamine compound obtained by reducing and amminating cyclic and acyclic dimer acids obtained as dimers of unsaturated fatty acids, and examples of the dimer diamine include linear, monocyclic, and polycyclic dimer diamines. The dimer diamine may contain a carbon-carbon double bond, or may be a hydrogenated product to which hydrogen has been added.

[0018] The aliphatic group derived from the dimer diamine is preferably at least one group selected from the group consisting of a group represented by the following formula (2-1), a group represented by the following formula (2-2), a group represented by the following formula (2-3), and a group represented by the following formula (2-4). Among these, the group represented by the following formula (2-2) is more preferred.

[0019] [ka]

[0020] In formulas (2-1) to (2-4), R 1 ~R 16 each independently represents a linear or branched hydrocarbon group, and * represents a bond. The bond * is bonded to N in the above formula (1).

[0021] In the above general formulas (2-1) to (2-4), R 1 ~R 16 The hydrocarbon group represented by may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8 , R 9 and R 10 , R 11 and R 12 , R 13 and R 14 , and R 15 and R 16 The total number of carbon atoms is preferably 7 or more and 50 or less. When the total number of carbon atoms is within the above range, the obtained polyimide-based temporary fixing material has better light transmittance and flexibility, and also has better compatibility with the solvent and other components of the resin having the imide skeleton in the main chain repeating unit. The total number of carbon atoms is more preferably 9 or more, even more preferably 12 or more, and even more preferably 14 or more. The total number of carbon atoms is more preferably 35 or less, even more preferably 25 or less, and even more preferably 18 or less.

[0022] In the group represented by the above formula (2-1), the group represented by the above formula (2-2), the group represented by the above formula (2-3), and the group represented by the above formula (2-4), the optical isomerism is not particularly limited and includes any optical isomerism.

[0023] The resin having an imide skeleton in a repeating unit of its main chain preferably includes a resin having no maleimide group and having an imide skeleton in a repeating unit of its main chain, and more preferably includes a resin having no polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in a repeating unit of its main chain.

[0024] The resin having no maleimide group and an imide skeleton in the repeating unit of the main chain preferably has a weight average molecular weight of 20,000 or more and 2,000,000 or less. When the resin having no maleimide group and an imide skeleton in the repeating unit of the main chain has a weight average molecular weight of 20,000 or more, the obtained polyimide-based temporary fixing material has better heat resistance. That is, during high-temperature processing, it is possible to further suppress the occurrence of voids and lifting between the support and the resin, and it is possible to further prevent the occurrence of increased adhesion to the adherend and the occurrence of adhesive residue when peeled off from the adherend. When the resin having no maleimide group and an imide skeleton in the repeating unit of the main chain has a weight average molecular weight of 2,000,000 or less, the resin having no maleimide group and an imide skeleton in the repeating unit of the main chain has better compatibility with solvents and other components. The weight average molecular weight of the resin that does not have a maleimide group and has an imide skeleton in the repeating unit of the main chain is more preferably 40,000 in the lower limit and 600,000 in the upper limit. In this specification, the weight average molecular weight is measured as a polystyrene equivalent molecular weight by gel permeation chromatography (GPC). Specifically, for example, the measurement can be performed using an APC system (manufactured by Waters) under the conditions of a mobile phase of THF, a flow rate of 1.0 mL / min, a column temperature of 40°C, a sample concentration of 0.2 mass%, and an RI-PDA detector. As the column, HR-MB-M 6.0 x 150 mm (manufactured by Waters) or the like can be used.

[0025] Specific examples of the resin that does not have a maleimide group and has an imide skeleton in the repeating unit of the main chain include resins that have a constitutional unit represented by the above formula (1) and have functional groups at both ends that do not have maleimide groups.

[0026] The resin having a constitutional unit represented by the above formula (1) and a functional group not having a maleimide group at both ends may have a constitutional unit represented by the following formula (3).

[0027] [ka]

[0028] In formula (3), P 2 represents an aromatic group, Q 2 represents a group having a substituted or unsubstituted aromatic structure.

[0029] In the above formula (3), P 2 is preferably an aromatic group having 5 to 50 carbon atoms. 2 is an aromatic group having 5 to 50 carbon atoms, the resulting polyimide-based temporary fixing material has excellent heat resistance. That is, the occurrence of voids and lifting between the support and the material during high-temperature processing can be further suppressed, and the occurrence of increased adhesion to the adherend and the occurrence of adhesive residue when peeled off from the adherend can be further prevented.

[0030] In the above formula (3), Q 2 is preferably a substituted or unsubstituted group having an aromatic structure having 5 to 50 carbon atoms. 2 is a substituted or unsubstituted group having an aromatic structure with 5 to 50 carbon atoms, the obtained polyimide-based temporary fixing material has excellent heat resistance. That is, the occurrence of voids and lifting between the support during high-temperature processing can be further suppressed, and the occurrence of increased adhesion to the adherend and the occurrence of adhesive residue when peeled off from the adherend can be further prevented.

[0031] Examples of the functional group not having a maleimide group include an aliphatic group, an alicyclic group, an aromatic group, an acid anhydride group, an amino group, etc. Specific examples include an unreacted one-terminal constituent group of an acid anhydride or diamine compound that is a raw material for a resin not having a maleimide group and having an imide skeleton in a repeating unit of the main chain. The functional groups not having a maleimide group at both ends of a resin having a structural unit represented by the above formula (1) and having functional groups not having a maleimide group at both ends may be the same or different.

[0032] The content of the structural unit represented by the above formula (1) in the resin having a functional group not having a maleimide group at both ends is preferably 30 mol % or more, more preferably 50 mol % or more, and is preferably 90 mol % or less, more preferably 80 mol % or less. When a resin having a structural unit represented by the above formula (1) and having a functional group not having a maleimide group at both ends has a structural unit represented by the above formula (3), the content of the structural unit represented by the above formula (3) is preferably 5 mol % or more, more preferably 10 mol % or more, even more preferably 20 mol % or more, and is preferably 50 mol % or less, more preferably 30 mol % or less. In the constitutional unit represented by the above formula (1) and the constitutional unit represented by the above formula (3), when the content of each of the constitutional units is within the above range, the resulting polyimide-based temporary fixing material can further suppress the occurrence of voids and lifting between the support and the material during high-temperature processing, and can be more easily peeled off from the adherend. The structural unit represented by the above formula (1) and the structural unit represented by the above formula (3) may have a block structure consisting of block components in which the respective structural units are arranged consecutively, or may have a random structure in which the respective structural units are arranged randomly.

[0033] Examples of a method for producing the resin having no maleimide group and an imide skeleton in the repeating unit of the main chain include a method of reacting a diamine compound with an aromatic acid anhydride.

[0034] As the diamine compound, either an aliphatic diamine compound or an aromatic diamine compound can be used. By using an aliphatic diamine compound as the diamine compound, the polyimide temporary fixing material obtained has superior light transmittance and flexibility, and can exhibit high conformability to an adherend having irregularities and can be more easily peeled off. Furthermore, by using an aromatic diamine compound as the diamine compound, the obtained polyimide-based temporary fixing material has superior heat resistance. The diamine compounds may be used alone or in combination of two or more kinds.

[0035] Examples of the aliphatic diamine compound include 1,10-diaminodecane, 1,12-diaminododecane, dimer diamine, 1,2-diamino-2-methylpropane, 1,2-diaminocyclohexane, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,7-diaminoheptane, 1,8-diaminomenthane, 1,8-diaminooctane, 1,9-diaminononane, 3,3'-diamino-N-methyldipropylamine, diaminomaleonitrile, 1,3-diaminopentane, bis(4-amino-3-methylcyclohexyl)methane, 1,2-bis(2-aminoethoxy)ethane, and 3(4),8(9)-bis(aminomethyl)tricyclo(5.2.1.02,6)decane.

[0036] Among the above aliphatic diamine compounds, dimer diamine is preferred from the viewpoints of light transmittance, flexibility, and compatibility with solvents and other components of the resin that does not have the maleimide group and has an imide skeleton in the repeating unit of the main chain.Specific examples of the above dimer diamine include dimer diamines that can constitute at least one group selected from the group consisting of the group represented by the above formula (2-1), the group represented by the formula (2-2), the group represented by the formula (2-3), and the group represented by the formula (2-4).

[0037] Examples of the aromatic diamine compound include 9,10-diaminophenanthrene, 4,4'-diaminooctafluorobiphenyl, 3,7-diamino-2-methoxyfluorene, 4,4'-diaminobenzophenone, 3,4-diaminobenzophenone, 3,4-diaminotoluene, 2,6-diaminoanthraquinone, 2,6-diaminotoluene, 2,3-diaminotoluene, 1,8-diaminonaphthalene, 2,4-diaminotoluene, 2,5-diaminotoluene, 1,4-diaminoanthraquinone, 1,5 -Diaminoanthraquinone, 1,5-diaminonaphthalene, 1,2-diaminoanthraquinone, 2,4-cumenediamine, 1,3-bisaminomethylbenzene, 1,3-bisaminomethylcyclohexane, 2-chloro-1,4-diaminobenzene, 1,4-diamino-2,5-dichlorobenzene, 1,4-diamino-2,5-dimethylbenzene, 4,4'-diamino-2,2'-bistrifluoromethylbiphenyl, bis(amino-3-chlorophenyl)ethane, bis(4-amino-3,5-dimethylphenyl) )methane, bis(4-amino-3,5-diethylphenyl)methane, bis(4-amino-3-ethyldiaminofluorene, 2,3-diaminonaphthalene, 2,3-diaminophenol, -5-methylphenyl)methane, bis(4-amino-3-methylphenyl)methane, bis(4-amino-3-ethylphenyl)methane, 4,4'-diaminophenylsulfone, 3,3'-diaminophenylsulfone, 2,2-bis(4,(4-aminophenoxy)phenyl)sulfone, 2,2-bis(4-(3-aminophenoxy)phenyl)sulfone, 4,4'-Oxy)phenyl)sulfone, 4,4'-oxydianiline, 4,4'-diaminodiphenyl sulfide, 3,4'-oxydianiline, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-3,3'-dimethoxybiphenyl, Bisaniline M, Bisaniline P, 9,9-bis(4-aminophenyl)fluorene, o-tolidine sulfone, methylenebis(anthranilic acid), 1,3-bis(4-aminophenoxy)-2,Examples of the amines include 2-dimethylpropane, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)butane, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 3,3',5,5'-tetramethylbenzidine, 4,4'-diaminobenzanilide, 2,2-bis(4-aminophenyl)hexafluoropropane, polyoxyalkylenediamines (e.g., Huntsman's Jeffamine D-230, D400, D-2000, and D-4000), 1,3-cyclohexanebis(methylamine), m-xylylenediamine, and p-xylylenediamine.

[0038] Examples of the aromatic acid anhydride include pyromellitic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,4,5-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4'-biphenylethertetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,5,6-pyridyltetracarboxylic acid, and 2,3,5,6-pyridyltetracarboxylic acid. 1,1-Bis(3,4-dicarboxyphenyl)ethane, 1,1-bis ... Bis(diphenyl)ethane, bis(2,3-dicarboxyphenyl)methane, bis(3,4-dicarboxyphenyl)methane, bis(3,4-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)ether, benzene-1,2,3,4-tetracarboxylic acid, 2,3,2',3'-benzophenonetetracarboxylic acid, 2,3,3',4'-benzophenonetetracarboxylic acid, phenanthrene-1,8,9,10-tetracarboxylic acid, pyridine Examples of the anhydrides of carboxylic acids include thiophene-2,3,5,6-tetracarboxylic acid, thiophene-2,3,4,5-tetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, 3,4,3',4'-biphenyltetracarboxylic acid, 2,3,2',3'-biphenyltetracarboxylic acid, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide, and 4,4'-(4,4'-isopropylidenediphenoxy)-bis(phthalic acid).

[0039] The content of the resin having no maleimide group and having an imide skeleton in the main chain repeating unit in 100 parts by mass of the resin having the imide skeleton in the main chain repeating unit is preferably 10 parts by mass and 90 parts by mass. When the content of the resin having no maleimide group and having an imide skeleton in the main chain repeating unit is within this range, the obtained polyimide-based temporary fixing material can be more easily peeled off from the adherend. From the viewpoint of further improving the peelability, the content of the resin having no maleimide group and having an imide skeleton in the main chain repeating unit is more preferably 20 parts by mass and 80 parts by mass.

[0040] The polyimide-based temporary fixing material preferably has photocuring or thermosetting properties. When the polyimide-based temporary fixing material is photocurable or thermosetting, the resin having the imide skeleton in the repeating unit of the main chain preferably contains a resin having a polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain. By containing a resin having a polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain, the obtained polyimide-based temporary fixing material is uniformly and quickly polymerized and crosslinked as a whole by irradiation with light, etc., and the elastic modulus increases, resulting in a significant decrease in adhesive strength. This makes it possible to prevent adhesion from increasing or leaving adhesive residue when peeled off. When the resin having an imide skeleton in a repeating unit of its main chain includes a resin which does not have the maleimide group and has an imide skeleton in a repeating unit of its main chain, it is preferable that the resin further includes a resin which has a polymerizable functional group having a carbon-carbon double bond and has an imide skeleton in a repeating unit of its main chain, in addition to the resin which does not have a maleimide group and has an imide skeleton in a repeating unit of its main chain. It should be noted that the carbon-carbon double bond contained in the aromatic ring is not regarded as the carbon-carbon double bond of the polymerizable functional group having the carbon-carbon double bond.

[0041] Examples of the functional group having a carbon-carbon double bond include an optionally substituted maleimide group, a citraconimide group, a vinyl ether group, an allyl group, a (meth)acryloyl group, etc. Among these, an optionally substituted maleimide group is preferred because it provides higher heat resistance. In this specification, the above-mentioned (meth)acryloyl means acryloyl or methacryloyl.

[0042] The resin having the polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain preferably has a functional group equivalent (weight average molecular weight / number of polymerizable functional groups having a carbon-carbon double bond) of 4000 or less. When the functional group equivalent of the polymerizable functional group having a carbon-carbon double bond is 4000 or less, the obtained polyimide-based temporary fixing material has better heat resistance. This is considered to be because the polymerizable functional group having a carbon-carbon double bond at a density of a certain level or more in the molecule of the resin shortens the distance between crosslinks, thereby suppressing adhesion enhancement. The functional group equivalent of the polymerizable functional group having a carbon-carbon double bond is more preferably 3000 or less, and even more preferably 2000 or less. Further, there is no particular preferred lower limit for the functional group equivalent weight of the polymerizable functional group having a carbon-carbon double bond, but the substantial lower limit is about 600.

[0043] The resin having a polymerizable functional group having a carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain preferably has a weight average molecular weight of 1000 or more and 100,000 or less. When the weight average molecular weight of the resin having a polymerizable functional group having a carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain is 1000 or more, the film formation of the obtained polyimide-based temporary fixing material is easy, and the obtained polyimide-based temporary fixing material exhibits a certain degree of flexibility, so that it can exhibit high conformability to an adherend having unevenness and can be peeled off more easily at the time of peeling. When the weight average molecular weight of the resin having a polymerizable functional group having a carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain is 100,000 or less, the solubility of the resin having a polymerizable functional group having a carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain in a solvent can be prevented from becoming too low. The weight average molecular weight of the resin having the above-mentioned polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain is more preferably 1,500 or more and 50,000 or less, and even more preferably 2,000 or more and less than 20,000.

[0044] In the resin having a polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in a repeating unit of the main chain, the polymerizable functional group having a carbon-carbon double bond may be present either at a side chain or at a terminal, but is preferably present at both terminals, and more preferably present at the side chain in addition to both terminals. The polymerizable functional groups having a carbon-carbon double bond at both ends of the resin having an imide skeleton in the repeating unit of the main chain are highly reactive, and can more fully cure the polyimide-based temporary fixing material by irradiation with light, etc. As a result, it is possible to more effectively prevent adhesion from increasing and adhesive residue from being left behind when peeled off. Furthermore, by having the polymerizable functional group having the carbon-carbon double bond and by having the polymerizable functional group having the carbon-carbon double bond in the side chain of the resin having the imide skeleton in the repeating unit of the main chain, the obtained polyimide-based temporary fixing material has better heat resistance. This is considered to be because the adhesion enhancement is further suppressed by shortening the distance between crosslinks. In addition, by having the polymerizable functional group having the carbon-carbon double bond and by having the polymerizable functional group having the carbon-carbon double bond in the side chain of the resin having the imide skeleton in the repeating unit of the main chain, it becomes easy to adjust the functional group equivalent to 4000 or less while making the weight average molecular weight 1000 or more. This allows the polyimide-based temporary fixing material to have sufficient initial adhesion, and at the same time, it is possible to more effectively prevent adhesion enhancement and the occurrence of adhesive residue during peeling.

[0045] As described above, in the resin having the polymerizable functional group having the carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain, the polymerizable functional group having the carbon-carbon double bond may be located either in a side chain or at a terminal. When either the side chain or the terminal is a functional group other than the polymerizable functional group having a carbon-carbon double bond (a functional group having no carbon-carbon double bond), the functional group having no carbon-carbon double bond may be, for example, an aliphatic group, an alicyclic group, an aromatic group, an acid anhydride group, an amino group, etc. Specifically, examples of the functional group having the polymerizable functional group having the carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain include an acid anhydride, an unreacted one-terminal constituent group of a diamine compound, etc., which are raw materials for the resin. When a resin having the above-mentioned polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in a repeating unit of its main chain has two or more functional groups not having a carbon-carbon double bond in a side chain or at an end, each functional group not having a carbon-carbon double bond may be the same or different.

[0046] Specific examples of the resin having a polymerizable functional group having a carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain include resins having a constitutional unit represented by the above formula (1) and having a polymerizable functional group having a carbon-carbon double bond at least in one of the terminal and the side chain.

[0047] The resin having a structural unit represented by the above formula (1) and having a polymerizable functional group having a carbon-carbon double bond at least in one of an end and a side chain may have at least one structural unit selected from the group consisting of a structural unit represented by the following formula (4-1) and a structural unit represented by the following formula (4-2).

[0048] [ka]

[0049] In formula (4-1), P 3 represents an aromatic group, Q 3 represents a group having a substituted or unsubstituted aromatic structure, and in formula (4-2), P 4 represents an aromatic group, R represents a substituted or unsubstituted branched aliphatic group or aromatic group, and X represents a polymerizable functional group having a carbon-carbon double bond.

[0050] P in the above formula (4-1) 3 and P in the above formula (4-2) 4 is preferably an aromatic group having 5 to 50 carbon atoms. 3 and P 4 is an aromatic group having 5 to 50 carbon atoms, the obtained polyimide-based temporary fixing material has excellent heat resistance. That is, the occurrence of voids and lifting between the support and the material during high-temperature processing can be further suppressed, and the occurrence of increased adhesion to the adherend and the occurrence of adhesive residue when peeled off from the adherend can be further prevented.

[0051] In the above formula (4-1), Q 3 is preferably a substituted or unsubstituted group having an aromatic structure having 5 to 50 carbon atoms.3 is a substituted or unsubstituted group having an aromatic structure with 5 to 50 carbon atoms, the obtained polyimide-based temporary fixing material has better heat resistance. That is, the occurrence of voids and lifting between the support during high-temperature processing can be further suppressed, and the occurrence of increased adhesion to the adherend and the occurrence of adhesive residue when peeled off from the adherend can be further prevented.

[0052] In the above formula (4-2), R is preferably a substituted or unsubstituted branched aliphatic or aromatic group having 2 to 100 carbon atoms. When R is a substituted or unsubstituted branched aliphatic or aromatic group having 2 to 100 carbon atoms, the obtained polyimide-based temporary fixing material has excellent flexibility, can exhibit high conformability to an adherend having irregularities, and can be more easily peeled off.

[0053] In the above formula (4-2), R is an aromatic group having an aromatic ester group or an aromatic ether group, and the aromatic ester group or the aromatic ether group in R is preferably bonded to X. Here, the "aromatic ester group" means a group in which an ester group is directly bonded to an aromatic ring, and the "aromatic ether group" means a group in which an ether group is directly bonded to an aromatic ring. By making the moiety bonded to the ester group or ether group an aromatic group in this way, the obtained polyimide-based temporary fixing material has better heat resistance. That is, the occurrence of voids and lifting during high-temperature processing can be more suppressed, and the occurrence of increased adhesion to the adherend or the occurrence of adhesive residue when peeled off from the adherend can be more prevented. On the other hand, by bonding X to R via an aromatic ester group or aromatic ether group, the carbon-carbon double bond in X does not conjugate with R, so that polymerization and crosslinking when heated or irradiated with light is not hindered.

[0054] The content of the structural unit represented by the above formula (1) in the resin having a polymerizable functional group having a carbon-carbon double bond at least in one of an end or a side chain is preferably 30 mol % or more, more preferably 50 mol % or more, and is preferably 90 mol % or less, more preferably 80 mol % or less. When a resin having a structural unit represented by the above formula (1) and having a polymerizable functional group having a carbon-carbon double bond at least in one of an end and a side chain has a structural unit represented by the above formula (4-1), the content of the structural unit represented by the above formula (4-1) is preferably 5 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more, and is preferably 50 mol % or less, more preferably 30 mol % or less. When a resin having a structural unit represented by the above formula (1) and having a polymerizable functional group having a carbon-carbon double bond at least in one of an end and a side chain has a structural unit represented by the above formula (4-2), the content of the structural unit represented by the above formula (4-2) is preferably 10 mol % or more, more preferably 20 mol % or more, and preferably 50 mol % or less, more preferably 30 mol % or less. In the constitutional unit represented by the above formula (1), the constitutional unit represented by the above formula (4-1), and the constitutional unit represented by the above formula (4-2), when the content of each of the constitutional units is within the above range, the resulting polyimide-based temporary fixing material can further suppress the occurrence of voids and lifting between the support and the material during high-temperature processing, and can be more easily peeled off from the adherend. The structural unit represented by the above formula (1), the structural unit represented by the above formula (4-1), and the structural unit represented by the above formula (4-2) may have a block structure consisting of block components in which the respective structural units are arranged consecutively, or may have a random structure in which the respective structural units are arranged randomly.

[0055] Examples of a method for producing a resin having a polymerizable functional group having a carbon-carbon double bond and an imide skeleton in a repeating unit of the main chain include the following methods. That is, first, a diamine compound is reacted with an aromatic acid anhydride to prepare an imide compound. Then, a compound having a functional group reactive with the functional group and a polymerizable functional group having a carbon-carbon double bond (hereinafter, also referred to as a "functional group-containing unsaturated compound") is reacted with the functional group of the imide compound to obtain a resin having the polymerizable functional group having the carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain. Alternatively, a resin having a functional group having a carbon-carbon double bond and an imide skeleton in the repeating unit of the main chain can be obtained by reacting a diamine compound with an aromatic acid anhydride to prepare an imide compound and then reacting the terminal of the imide compound with, for example, maleic anhydride.

[0056] As the diamine compound and aromatic acid anhydride used in the method for producing a resin having a polymerizable functional group with a carbon-carbon double bond and having an imide skeleton in a repeating unit of the main chain, the same compounds as those used in the method for producing a resin having no maleimide group and having an imide skeleton in a repeating unit of the main chain can be used.

[0057] The functional group-containing unsaturated compound is selected according to the functional group at the end or side chain of the imide compound. For example, when the functional group at the end or side chain of the imide compound is a hydroxyl group, examples of the functional group-containing unsaturated compound include a maleimide compound having a carboxy group, a vinyl compound having an ether group, an allyl compound having a glycidyl group, an allyl ether compound having a glycidyl group, a vinyl ether compound having a glycidyl group, an allyl compound having an isocyanate group, and a (meth)acryloyl compound having an isocyanate group. Furthermore, for example, when the functional group at the end or side chain of the imide compound is a carboxy group, examples of the functional group-containing unsaturated compound include an allyl compound having a hydroxyl group, an allyl compound having a glycidyl group, an allyl ether compound having a glycidyl group, and a vinyl ether compound having a glycidyl group. Examples of the maleimide compound having a carboxy group include maleimide acetate, maleimidopropionic acid, maleimidobutyric acid, maleimidohexanoic acid, trans-4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid, and 19-maleimido-17-oxo-4,7,10,13-tetraoxa-16-azanonadecanoic acid. An example of the vinyl compound having an ether group is butyl vinyl ether. An example of the allyl compound having a glycidyl group is diallyl monoglycidyl isocyanurate. Examples of the allyl ether compound having a glycidyl group include allyl glycidyl ether, glycerin diallyl monoglycidyl ether, and the like. Examples of the vinyl ether compound having a glycidyl group include glycidyloxyethyl vinyl ether, glycidyloxybutyl vinyl ether, glycidyloxyhexyl vinyl ether, glycidyl diethylene glycol vinyl ether, and glycidyl cyclohexane dimethanol monovinyl ether. The allyl compound having an isocyanate group includes, for example, allyl isocyanate. Examples of the (meth)acryloyl compound having an isocyanate group include 2-(meth)acryloyloxyethyl isocyanate. Examples of the allyl compound having a hydroxyl group include trimethylolpropane diallyl ether and pentaerythritol triallyl ether.

[0058] The content of the resin having the polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain in 100 parts by mass of the resin having the imide skeleton in the repeating unit of the main chain is preferably 10 parts by mass, and preferably 100 parts by mass. When the content of the resin having the polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain is within this range, the polyimide temporary fixing material can be more easily peeled off at the time of peeling. From the viewpoint of further improving the peelability, the content of the resin having the polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain is more preferably 20 parts by mass, even more preferably 30 parts by mass, and more preferably 90 parts by mass, even more preferably 80 parts by mass, and even more preferably 70 parts by mass.

[0059] In the case where the polyimide-based temporary fixing material is photocurable or thermocurable, and the resin having the imide skeleton in the repeating unit of the main chain does not have the maleimide group, and contains a resin having an imide skeleton in the repeating unit of the main chain, it is preferable that the polyimide-based temporary fixing material further contains a polyfunctional monomer or polyfunctional oligomer (hereinafter simply referred to as "polyfunctional monomer or polyfunctional oligomer") which has two or more polymerizable functional groups having a carbon-carbon double bond in the molecule and has a molecular weight of 5,000 or less. In addition, even when the resin having the imide skeleton in the repeating unit of the main chain has the polymerizable functional group having the carbon-carbon double bond and contains a resin having an imide skeleton in the repeating unit of the main chain, the polyimide-based temporary fixing material may further contain the polyfunctional monomer or polyfunctional oligomer. By including the polyfunctional monomer or polyfunctional oligomer, the polyimide-based temporary fixing material is more efficiently three-dimensionally reticulated by irradiation with light or the like, and can more effectively prevent enhanced adhesion and the occurrence of glue residue when peeled off.

[0060] In addition, when the resin having the imide skeleton in the repeating unit of the main chain is not reactive, the polyimide temporary fixing material needs to have reactivity as a whole by further containing another component having a reactive functional group. As such another component having a reactive functional group, it is preferable to use the above-mentioned polyfunctional monomer or polyfunctional oligomer. As an example of a case where the resin having the imide skeleton in the repeating unit of the main chain is not reactive, for example, the resin having the imide skeleton in the repeating unit of the main chain does not have the maleimide group and only contains a resin having the imide skeleton in the repeating unit of the main chain.

[0061] Examples of the polymerizable functional group having a carbon-carbon double bond in the polyfunctional monomer or oligomer include an optionally substituted maleimide group, a citraconimide group, a vinyl ether group, an allyl group, and a (meth)acryloyl group. Among them, an optionally substituted maleimide group is preferred because it provides higher heat resistance. In particular, the polyfunctional monomer or oligomer is preferably a bismaleimide compound.

[0062] The polyfunctional monomer or oligomer preferably has a group derived from a diamine compound. As the diamine compound, either an aliphatic diamine compound or an aromatic diamine compound can be used, but an aliphatic diamine compound is preferred. That is, the polyfunctional monomer or oligomer more preferably has an aliphatic group derived from a diamine compound. By using an aliphatic diamine compound as the diamine compound, the obtained polyimide-based temporary fixing material has better light transmittance. In addition, the obtained polyimide-based temporary fixing material has better flexibility, can exhibit high conformability to an adherend having unevenness, and can be more easily peeled off at the time of peeling.

[0063] Among the above aliphatic diamine compounds, the above dimer diamines are preferred from the viewpoints of light transmittance, flexibility, and compatibility with the solvent of the polyfunctional monomer or polyfunctional oligomer and other components.

[0064] The content of the polyfunctional monomer or polyfunctional oligomer in a total of 100 parts by mass of the resin having the imide skeleton in the main chain repeating unit and the polyfunctional monomer or polyfunctional oligomer is preferably 5 parts by mass and 90 parts by mass. When the content of the polyfunctional monomer or polyfunctional oligomer is within this range, the polyimide-based temporary fixing material can be more easily peeled off at the time of peeling. From the viewpoint of further improving the peelability, the content of the polyfunctional monomer or polyfunctional oligomer is more preferably 10 parts by mass and more preferably 50 parts by mass.

[0065] When the polyimide-based temporary fixing material contains the resin having no maleimide group and an imide skeleton in the repeating unit of the main chain, the resin having the polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain, and the polyfunctional monomer or oligomer, the preferred lower limit of the total content of the resin having the polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain and the polyfunctional monomer or oligomer in a total of 100 parts by mass is 20 parts by mass, and the preferred upper limit is 80 parts by mass. When the total content of the resin having the polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in the repeating unit of the main chain and the polyfunctional monomer or oligomer is within this range, the polyimide-based temporary fixing material can be more easily peeled off at the time of peeling. From the viewpoint of further improving the releasability, the lower limit of the total content of the resin having a polymerizable functional group having a carbon-carbon double bond and having an imide skeleton in a repeating unit of its main chain, and the polyfunctional monomer or polyfunctional oligomer is more preferably 30 parts by mass, even more preferably 40 parts by mass, still more preferably 50 parts by mass, and more preferably 70 parts by mass.

[0066] The polyimide-based temporary fixing material preferably contains a compound having a maleimide group. By containing the compound having a maleimide group, the obtained polyimide-based temporary fixing material has better heat resistance. The compound having a maleimide group is preferably a bismaleimide compound, or a resin having a maleimide group and an imide skeleton in the repeating unit of the main chain. That is, the polyimide-based temporary fixing material preferably contains the bismaleimide compound as the polyfunctional monomer or polyfunctional oligomer, or contains a resin having a polymerizable functional group having a carbon-carbon double bond and a maleimide group as the polymerizable functional group having a carbon-carbon double bond of a resin having an imide skeleton in the repeating unit of the main chain.

[0067] The polyimide-based temporary fixing material preferably further contains a silicone compound or a fluorine compound, which acts as a surface modifier. The above silicone compounds and fluorine compounds have excellent heat resistance, and therefore prevent the curable resin composition from burning even when subjected to high-temperature processing at 300°C or higher. During peeling, they bleed out to the interface with the adherend, making peeling easier. Examples of the silicone compound include silicone oil, silicone diacrylate, and silicone graft copolymer. The fluorine compound may, for example, be a hydrocarbon compound having a fluorine atom.

[0068] The silicone compound or fluorine compound preferably has a functional group capable of crosslinking with the resin having an imide skeleton in the main chain repeating unit or the polyfunctional monomer or polyfunctional oligomer. The silicone compound or fluorine compound has a functional group capable of crosslinking with the resin having the imide skeleton in the repeating unit of the main chain or the polyfunctional monomer or oligomer, and is incorporated into the resin by chemical reaction with the resin having the imide skeleton in the repeating unit of the main chain or the polyfunctional monomer or oligomer by irradiation with light or reaction with a crosslinking agent. This makes it possible to prevent the silicone compound or fluorine compound from adhering to the adherend and contaminating it. Examples of the functional group capable of crosslinking with the resin having the imide skeleton in the repeating unit of the main chain or the polyfunctional monomer or oligomer include a carboxy group, a radically polymerizable unsaturated bond (e.g., a vinyl group, a (meth)acryloyl group, or a maleimide group which may be substituted), a hydroxy group, an amide group, an isocyanate group, and an epoxy group. Among these, from the viewpoints of environmental friendliness and ease of disposal, the resin having the imide skeleton in the repeating unit of the main chain or the silicone compound having a functional group capable of crosslinking with the polyfunctional monomer or polyfunctional oligomer is preferred.

[0069] As the resin having an imide skeleton in the repeating unit of the main chain or the silicone compound having a functional group crosslinkable with the polyfunctional monomer or polyfunctional oligomer, a silicone compound having a siloxane skeleton in the main chain and a polymerizable functional group having a carbon-carbon double bond in a side chain or at an end is preferred. The silicone compound having a siloxane skeleton in the main chain and a polymerizable functional group having a carbon-carbon double bond in the side chain or at the end is preferably at least one selected from the group consisting of a silicone compound represented by the following formula (5-1), a silicone compound represented by the following formula (5-2), and a silicone compound represented by the following formula (5-3): These silicone compounds are particularly excellent in heat resistance and have high polarity, so that they easily bleed out from the polyimide-based temporary fixing material.

[0070] [ka]

[0071] X in the above formulae (5-1) to (5-3) and Y in the above formulae (5-1) and (5-3) each independently represent an integer of 0 or more and 1200 or less, and R in the above formulae (5-1) to (5-3) represents a functional group having a carbon-carbon double bond.

[0072] In the above formulas (5-1) to (5-3), examples of the polymerizable functional group having a carbon-carbon double bond represented by R include, for example, an optionally substituted maleimide group, a citraconimide group, a vinyl ether group, an allyl group, and a (meth)acryloyl group. Among them, an optionally substituted maleimide group is preferred because the resulting polyimide-based temporary fixing material has better heat resistance. In addition, when there are multiple Rs in the above formulas (5-1) to (5-3), each R may be the same or different.

[0073] Among the silicone compounds represented by the above formulas (5-1) to (5-3), commercially available examples include EBECRYL350, EBECRYL1360 (both manufactured by Daicel-Allnex Corporation), etc. Other examples include BYK-UV3500 (manufactured by BYK-Chemie Corporation), TEGO RAD2250 (manufactured by Evonik Corporation) (in both cases, R is an acryloyl group), etc.

[0074] The content of the silicone compound or fluorine compound is preferably 0.1 parts by mass at the lower limit and 20 parts by mass at the upper limit with respect to 100 parts by mass of the resin having the imide skeleton in the main chain repeating unit and the polyfunctional monomer or oligomer. By the content of the silicone compound or fluorine compound being within this range, the obtained polyimide-based temporary fixing material has excellent releasability without contaminating the adherend. From the viewpoint of further improving releasability while suppressing contamination, the more preferred lower limit of the content of the silicone compound or fluorine compound is 0.3 parts by mass, and the more preferred upper limit is 10 parts by mass.

[0075] The polyimide-based temporary fixing material preferably further contains a polymerization initiator. The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator, with a photopolymerization initiator being preferred.

[0076] Examples of the photopolymerization initiator include those that are activated by irradiation with light having a wavelength of 250 to 800 nm. Among them, the photopolymerization initiator is preferably a compound having a molar absorption coefficient of 1 or more at 365 nm, since it is unlikely to overlap with the absorption wavelength of the resin having the imide skeleton in the repeating unit of the main chain or the polyfunctional monomer or polyfunctional oligomer, and is sufficiently activated when the polyimide-based temporary fixing material is irradiated with light. The photopolymerization initiator more preferably includes a compound having a molar absorption coefficient of 200 or more at 365 nm, and further preferably includes a compound having a molar absorption coefficient of 350 or more at 365 nm. There is no particular preferred upper limit of the molar absorption coefficient at 365 nm of the compound having a molar absorption coefficient of 1 or more at 365 nm, but the substantial upper limit is 2000.

[0077] Examples of the photopolymerization initiator include acetophenone derivatives, benzoin ether compounds, ketal derivatives, and phosphine oxide derivatives. The acetophenone derivatives include, for example, methoxyacetophenone. Examples of the benzoin ether compounds include benzoin propyl ether and benzoin isobutyl ether. Examples of the ketal derivative include benzyl dimethyl ketal and acetophenone diethyl ketal. Further, examples of the photopolymerization initiator include bis(η5-cyclopentadienyl)titanocene derivative compounds, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenyl ketone, and 2-hydroxymethylphenylpropane. These photopolymerization initiators may be used alone or in combination of two or more kinds.

[0078] The content of the polymerization initiator is preferably 0.1 parts by mass at the lower limit and 10 parts by mass at the upper limit with respect to 100 parts by mass of the resin having the imide skeleton in the main chain repeating unit and the polyfunctional monomer or oligomer. By the content of the polymerization initiator being within this range, the entire polyimide-based temporary fixing material is polymerized and crosslinked uniformly and quickly by irradiation with light or the like, and the elastic modulus increases, which greatly reduces the adhesive strength, and can prevent the occurrence of increased adhesion or the occurrence of adhesive residue when peeled off. The more preferable lower limit of the content of the polymerization initiator is 0.3 parts by mass, and the more preferable upper limit is 3 parts by mass.

[0079] The polyimide-based temporary fixing material may further contain a gas generating agent. By containing the gas generating agent, even after high-temperature processing at 300°C or higher, gas generated by light irradiation or the like is released at the interface with the adherend, so that the adherend can be peeled off more easily and without leaving any adhesive residue. In addition, even when a thin adherend is peeled off after high-temperature processing at 300°C or higher, damage to the adherend can be prevented.

[0080] The gas generating agent preferably has a weight loss rate of 5% or less at 300°C when heated from 30°C to 300°C at a temperature increase rate of 10°C / min in a nitrogen atmosphere in TG-DTA (thermogravimetry-differential thermal analysis) measurement. If the weight loss rate is 5% or less, the gas generating agent is less likely to decompose even when a high-temperature processing treatment is performed at 300°C or higher, and the polyimide-based temporary fixing material has excellent heat resistance. In other words, peeling can be further suppressed during high-temperature processing, and enhanced adhesion and the occurrence of adhesive residue during peeling can be further prevented. The above TG-DTA (thermogravimetry-differential thermal analysis) measurement can be carried out using, for example, a TG-DTA device (manufactured by Hitachi High-Tech Science Corporation, "STA7200RV") or the like.

[0081] Examples of the gas generating agent include a gas generating agent that generates a gas by heating, a gas generating agent that generates a gas by irradiating light, etc. Among these, a gas generating agent that generates a gas by irradiating light is preferred, and a gas generating agent that generates a gas by irradiating ultraviolet light is more preferred. Examples of the gas generating agent include tetrazole compounds or their salts, triazole compounds or their salts, azo compounds, azide compounds, xanthone acetate, carbonates, etc. These gas generating agents may be used alone or in combination of two or more. Among them, tetrazole compounds or their salts are preferred because of their excellent heat resistance.

[0082] The content of the gas generating agent is preferably 5 parts by mass at the lower limit and 50 parts by mass at the upper limit relative to 100 parts by mass of the resin having the imide skeleton in the main chain repeating unit and the polyfunctional monomer or oligomer. By having the content of the gas generating agent within this range, the obtained polyimide-based temporary fixing material has particularly excellent releasability. The more preferred lower limit of the content of the gas generating agent is 8 parts by mass, and the more preferred upper limit is 30 parts by mass.

[0083] The polyimide-based temporary fixing material may further contain an inorganic filler. By containing the inorganic filler, the resulting polyimide-based temporary fixing material can suppress a decrease in elastic modulus at high temperatures, and even in the case of high-temperature processing at 300°C or higher, peeling during high-temperature processing can be further suppressed.

[0084] Examples of the inorganic filler include at least one inorganic filler selected from the group consisting of oxides of silicon, titanium, aluminum, calcium, boron, magnesium, and zirconia, and composites thereof. Among these, silica and talc are preferred because they are commercially available at low cost and easily available.

[0085] The inorganic filler may be surface-modified. Examples of the functional group that may be used to modify the surface of the inorganic filler include an alkylsilane group, a methacryloyl group, and a dimethylsiloxane group. Among these, the dimethylsiloxane group is preferred because it has a suitable hydrophobicity.

[0086] The preferred lower limit of the average particle size of the inorganic filler is 5 nm, and the preferred upper limit is 30 μm. By the average particle size of the inorganic filler being within this range, the obtained polyimide-based temporary fixing material can be more suppressed from peeling during high-temperature processing, and can be peeled off by peeling when peeling. The more preferred lower limit of the average particle size of the inorganic filler is 10 nm, and the more preferred upper limit is 20 μm, and the even more preferred lower limit is 15 nm, and the even more preferred upper limit is 15 μm. The average particle size is preferably a number average particle size, which can be determined, for example, by observing 50 particles of any inorganic filler with an electron microscope or an optical microscope, calculating the average particle size of each inorganic filler, or by performing laser diffraction particle size distribution measurement.

[0087] The content of the inorganic filler is preferably 1 part by mass at the lower limit and 20 parts by mass at the upper limit with respect to 100 parts by mass of the resin having the imide skeleton in the main chain repeating unit and the polyfunctional monomer or oligomer. By the content of the inorganic filler being within this range, the obtained polyimide-based temporary fixing material can be more suppressed from peeling during high-temperature processing, and can be peeled off by peeling at the time of peeling. The more preferred lower limit of the content of the inorganic filler is 3 parts by mass, the more preferred upper limit is 15 parts by mass, the even more preferred lower limit is 5 parts by mass, and the even more preferred upper limit is 10 parts by mass.

[0088] The polyimide-based temporary fixing material may further contain an ultraviolet absorbing agent. By including the ultraviolet absorber, the polyimide-based temporary fixing material has improved releasability from a support even when the laser light irradiated has a relatively low energy.

[0089] As the ultraviolet absorbing agent, for example, a compound having an absorption wavelength at the wavelength of the laser light described later is preferable, a compound having an absorption wavelength of 200 nm or more and 550 nm or less is more preferable, a compound having an absorption wavelength at at least one wavelength selected from the group consisting of 532 nm, 355 nm, and 308 nm is even more preferable, and a compound having an absorption wavelength at at least one wavelength selected from the group consisting of 355 nm and 308 nm is even more preferable.As such ultraviolet absorbing agent, for example, benzotriazole-based ultraviolet absorbing agent, benzophenone-based ultraviolet absorbing agent, triazine-based ultraviolet absorbing agent, salicylate-based ultraviolet absorbing agent, cyanoacrylate-based ultraviolet absorbing agent, etc. can be mentioned. More specific examples include Uvinul 3035, Uvinul 3039, Uvinul 3030FF, Tinuvin 1577ED, Tinuvin 120, Tinuvin 400 (all manufactured by BASF).

[0090] The content of the ultraviolet absorber is preferably 1 part by mass at the lower limit and 50 parts by mass at the upper limit with respect to 100 parts by mass of the resin having the imide skeleton in the main chain repeating unit and the polyfunctional monomer or oligomer. By having the content of the ultraviolet absorber within this range, the polyimide temporary fixing material obtained is excellent in both the peelability from the support when irradiated with low-energy laser light and the heat resistance of the polyimide temporary fixing material. The more preferred lower limit of the content of the ultraviolet absorber is 2 parts by mass, and the more preferred upper limit is 30 parts by mass.

[0091] The polyimide-based temporary fixing material may contain known additives, such as a photosensitizer, a heat stabilizer, an antioxidant, an antistatic agent, a plasticizer, a resin, a surfactant, and a wax.

[0092] Examples of a method for producing the polyimide-based temporary fixing material include a method in which a resin having the imide skeleton in a repeating unit of the main chain and additives to be blended as necessary are mixed using a bead mill, ultrasonic dispersion, homogenizer, high-output disperser, roll mill, or the like.

[0093] The polyimide-based temporary fixing material preferably has a light transmittance of 0.1% or more at a wavelength of 405 nm. When the polyimide-based temporary fixing material has photocurability, the polyimide-based temporary fixing material can be cured more sufficiently by having a light transmittance of 0.1% or more at a wavelength of 405 nm. The light transmittance of the 405 nm wavelength is more preferably 0.3% or more, more preferably 0.4% or more, even more preferably 0.5% or more, even more preferably 10% or more, even more preferably 15% or more, even more preferably 20% or more, and particularly preferably 25% or more. Further, although there is no particular preferred upper limit for the light transmittance at a wavelength of 405 nm, the substantial upper limit is about 90% to 95%. The light transmittance at a wavelength of 405 nm is measured using a spectrophotometer. Examples of the spectrophotometer include U-3900 (manufactured by Hitachi High-Tech Science Corporation). The optical path length at this time is the thickness of the polyimide-based temporary fixing material.

[0094] When the polyimide-based temporary fixing material has a curing property, the preferred lower limit of the gel fraction after curing is 70% by mass, and the preferred upper limit is 95% by mass. When the gel fraction after curing is within the above range, the polyimide-based temporary fixing material can be more easily peeled off from the adherend. The more preferred lower limit of the gel fraction after curing of the polyimide-based temporary fixing material is 75% by mass, and the more preferred upper limit is 90% by mass. In addition, in the case of a photocurable polyimide-based temporary fixing material, the gel fraction after curing is measured by applying a wavelength of 365 nm to the polyimide-based temporary fixing material with an irradiation intensity of 70 mW / cm 2After curing by irradiating with ultraviolet light for 300 seconds, or, in the case of a thermosetting polyimide temporary fixing material, by heating at 150°C for 10 minutes, the viscosity is measured by the following method. That is, first, the polyimide-based temporary fixing material is cut into a flat rectangular shape of 50 mm x 100 mm to prepare a test piece. The obtained test piece is immersed in toluene at 23°C for 24 hours, then removed from the toluene and dried at 110°C for 1 hour. The mass of the test piece after drying is measured, and the gel fraction is calculated using the following formula. Note that no separator for protecting the polyimide-based temporary fixing material is laminated on the test piece. Gel fraction (mass%) = 100 × (W2-W0) / (W1-W0) (W0: mass of the substrate, W1: mass of the test piece before immersion, W2: mass of the test piece after immersion and drying)

[0095] The preferred lower limit of the thickness of the polyimide-based temporary fixing material is 5 μm, and the preferred upper limit is 550 μm. When the thickness of the polyimide-based temporary fixing material is 5 μm or more, the polyimide-based temporary fixing material can have sufficient pressure-sensitive or heat-sensitive adhesive strength at the beginning. When the thickness of the polyimide-based temporary fixing material is 550 μm or less, the polyimide-based temporary fixing material can exhibit high flexibility, can exhibit high conformability to an adherend having unevenness, and can be easily peeled off at the time of peeling. The more preferred lower limit of the thickness of the polyimide-based temporary fixing material is 10 μm, even more preferred lower limit is 20 μm, and even more preferred lower limit is 30 μm. The more preferred upper limit of the thickness of the polyimide-based temporary fixing material is 400 μm, even more preferred upper limit is 300 μm, even more preferred upper limit is 200 μm, and particularly preferred upper limit is 150 μm.

[0096] The polyimide-based temporary fixing material is preferably in the form of a tape. In this case, the polyimide-based temporary fixing material may have the polyimide-based temporary fixing material on one or both surfaces of a substrate, or may not have a substrate. When the substrate is not used, it is not necessary to select a substrate having both light transmittance and heat resistance, and the polyimide-based temporary fixing material can be made cheaper and simpler in structure. In the case where the substrate is used, examples of the substrate include resin sheets such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, urethane, polyimide, polyether ether ketone (PEEK), polyamide (PA), etc. Resin sheets with high light transmittance can be suitably used. In addition, sheets with a mesh structure, sheets with holes, glass, etc. can also be used. From the viewpoint of improving light transmittance and flexibility, the lower limit of the thickness of the substrate is preferably 5 μm, more preferably 10 μm, and the upper limit is preferably 150 μm, more preferably 100 μm.

[0097] Examples of the electronic components include semiconductor devices, microelectromechanical systems (MEMS), and electronic devices. In particular, the method for producing an electronic component of the present invention is suitable as a method for processing semiconductor devices. The semiconductor device may be, for example, a silicon wafer.

[0098] The support may be made of glass, quartz, sapphire, or the like.

[0099] As described above, the polyimide-based temporary fixing material is preferably photocurable or thermosetting, and preferably includes a curing step of curing the polyimide-based temporary fixing material after the support fixing step and before the processing step described below. When the polyimide-based temporary fixing material is photocurable, the method for producing an electronic component of the present invention preferably includes a photocuring step of curing the polyimide-based temporary fixing material by irradiating light after the support fixing step and before the processing step described below. When the polyimide-based temporary fixing material is thermosetting, the method for producing an electronic component of the present invention preferably includes a heat curing step of curing the polyimide-based temporary fixing material by heating after the support fixing step and before the processing step described below.

[0100] The method for producing an electronic component of the present invention includes a process for subjecting the electronic component fixed to the support to a heat treatment or a process involving heat generation. Even if the electronic component is subjected to a heat treatment or a process involving heat generation in this manner, the method for producing an electronic component of the present invention can reduce damage to the electronic component and easily peel off the support in the support peeling process described below.

[0101] The heat treatment may be, for example, a reflow treatment. The heat generating process is, for example, a sputtering process.

[0102] The method for producing an electronic component of the present invention includes a support peeling step of irradiating a laser beam from the support side to peel the support from the electronic component. By irradiating a laser beam to peel the support from the electronic component in this manner, the method for producing an electronic component of the present invention can reduce damage to the electronic component in the support peeling step and easily peel the support even if a heat treatment or a treatment involving heat generation is performed in the treatment step.

[0103] The wavelength of the laser light is preferably 200 nm or more and 550 nm or less. By having the wavelength of the laser light in this range, it is possible to isolate the support while suppressing thermal damage to electronic components caused by laser light irradiation. The wavelength of the laser light is not particularly limited as long as it is a wavelength used in laser peeling, but 532 nm, 355 nm, or 308 nm is usually preferably used. When a wavelength of 240 nm or less is used, it is particularly preferable to use quartz as the support and to carry out the laser light irradiation in a vacuum or nitrogen atmosphere.

[0104] The preferred lower limit of the irradiation intensity of the laser light is 50 mJ / cm 2 , the preferred upper limit is 2000 mJ / cm 2 When the irradiation intensity of the laser beam is within this range, peeling from the support can be more easily performed by irradiation with the laser beam. A more preferable lower limit of the irradiation intensity of the laser beam is 100 mJ / cm. 2 , the preferred upper limit is 1500 mJ / cm 2 It is. In addition, in order to prevent carbonization of the temporary fixing material due to irradiation with the laser light, the irradiation intensity of the laser light is usually set to 300 mJ / cm. 2 However, if a polyimide-based temporary fixing material is used as the temporary fixing material from the viewpoint of peelability, the maximum allowable range is 200 mJ / cm 2 More preferably, it is 250 mJ / cm or more. 2 More preferably, it is equal to or greater than this.

[0105] The laser light may be a CW (Continuous Wave) laser or a pulsed laser.

[0106] When the laser light is a pulsed laser, the pulse width of the laser light is preferably 100 nsec or less. When the pulse width of the laser light is in this range, the processability when peeling off the support is improved. From the viewpoint of further shortening the irradiation time, the pulse width of the laser light is more preferably 50 nsec or less, and further preferably 20 nsec or less. Since the irradiation time is shortened even with the same amount of irradiation energy, the shorter the pulse width of the laser light, the more preferable it is, but the lower limit is usually about 1 fsec to 1 psec.

[0107] In the support peeling step, it is preferable that the laser light is irradiated so as to scan the polyimide-based temporary fixing material through the support. By irradiating the polyimide-based temporary fixing material with the laser light so as to scan the polyimide-based temporary fixing material through the support, the support and the polyimide-based temporary fixing material can be peeled off more easily. When the laser light is irradiated so as to scan the polyimide-based temporary fixing material through the support, it is preferable to scan without tracing the same line, and it is more preferable to scan in a Z-shape (scanning in one direction, then descending by a pitch width at the end, and repeating scanning in the opposite direction) or in a spiral shape.

[0108] The intensity distribution in the irradiation shape of the laser beam preferably has a Gaussian waveform, which makes it possible to stabilize the processed shape and facilitate uniform processing. In addition, it is preferable that the intensity distribution in the irradiation shape of the laser light is flattened. By flattening the intensity distribution in the irradiation shape of the laser light, the difference in intensity in the places irradiated with the laser is reduced. Therefore, it is not necessary to irradiate the laser light in an overlapping manner, and the laser light can be irradiated more uniformly. The flattening treatment may be carried out, for example, using a splitter or a mask.

[0109] The irradiation shape of the laser beam is preferably a rectangle. By using a rectangular irradiation shape of the laser beam, it becomes easier to irradiate the laser beam more uniformly without leaving any gaps.

[0110] In the support peeling step, it is preferable to ventilate the room when irradiating the laser light. When the laser light is irradiated, smoke may be generated. By exhausting the smoke by ventilation, it is possible to prevent the laser light from being blocked by the smoke. As a result, the workability is further improved. Effect of the Invention

[0111] According to the present invention, it is possible to provide a method for manufacturing an electronic component that reduces damage to the electronic component and enables the support to be easily peeled off even when the electronic component is subjected to a heat treatment or a treatment involving heat generation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0112] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0113] (Synthesis Example 1) 250 mL of toluene was added to a 500 mL round-bottom flask equipped with a Teflon (registered trademark) stirrer. 31.9 g (0.06 mol) of dimer diamine (manufactured by Croda, "Priamine 1075"), 5.5 g (0.015 mol) of 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane, and 39 g (0.0765 mol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride were added in this order. A Dean-Stark tube and a condenser were attached to the flask, and the resulting mixture was refluxed for 6 hours and cooled to room temperature. A brown resin (maleimide group-free PI) was obtained, which has a constitutional unit represented by the following formula (6-1) and a constitutional unit represented by the following formula (6-2), does not have a maleimide group, and has an imide skeleton in the repeating unit of the main chain. The weight-average molecular weight of the obtained maleimide group-free PI was measured by gel permeation chromatography (GPC, apparatus name: Acquity APC system (manufactured by Waters Corporation)) using THF as an eluent and an HR-MB-M 6.0 x 150 mm (manufactured by Waters Corporation) as a column, and was found to be 78,000.

[0114] [ka]

[0115] (Synthesis Example 2) 250 mL of toluene was added to a 500 mL round-bottom flask equipped with a Teflon stirrer. Then, 35 g (0.35 mol) of triethylamine and 35 g (0.36 mol) of methanesulfonic anhydride were added and stirred to form a salt. After stirring for 10 minutes, 56 g (0.1 mol) of dimer diamine (Croda, Priamine 1075) and 19.1 g (0.09 mol) of pyromellitic anhydride were added in this order. A Dean-Stark trap and a condenser were attached to the flask, and the mixture was refluxed for 2 hours to form an amine-terminated diimide. After cooling the reactants below room temperature, 12.8 g (0.13 mol) of maleic anhydride was added, followed by 5 g (0.05 mol) of methanesulfonic anhydride. The resulting mixture was refluxed for an additional 12 hours, cooled to room temperature, and 300 mL of toluene was added to the flask, which was allowed to stand to separate into layers, and the lower layer, which was an impurity, was removed. The resulting solution was filtered through a glass frit funnel filled with silica gel, and the solvent was then removed under vacuum to obtain an amber-colored wax-like resin (C=C functional group-containing PI) represented by the following formula (7) having maleimide groups at both ends and an imide skeleton in the repeating unit of the main chain. The weight-average molecular weight of the obtained C=C functional group-containing PI was measured by gel permeation chromatography (GPC, apparatus name: Acquity APC system (manufactured by Waters Corporation)) using THF as an eluent and an HR-MB-M 6.0 x 150 mm (manufactured by Waters Corporation) as a column, and was found to be 5,000.

[0116] [ka]

[0117] In formula (7), n is the number of repetitions.

[0118] (Preparation of polyimide-based temporary fixing material) To 150 mL of toluene, 70 parts by mass of the maleimide group-free PI obtained in Synthesis Example 1 and 30 parts by mass of the C=C functional group-containing PI obtained in Synthesis Example 2 were added. Furthermore, 1 part by mass of bifunctional silicone acrylate (manufactured by BYK-Chemie, "BYK-UV3500") as a silicone compound, 2 parts by mass of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Resins, "Omnirad 819") as a photopolymerization initiator, and 10 parts by mass of an ultraviolet absorber (manufactured by BASF, "Tinuvin400") were added to prepare a toluene solution of the resin composition. The obtained toluene solution of the resin composition was applied with a doctor knife onto the release-treated surface of a 50 μm-thick PET film that had been subjected to one-sided release treatment so that the dry film had a thickness of 80 μm, and the coating solution was dried by heating for 10 minutes at 130° C. Thereafter, the release-treated surface of another release PET film was bonded to the surface of the temporary fixing material to obtain a polyimide-based temporary fixing material.

[0119] (5% weight loss temperature of cured product) The obtained polyimide-based temporary fixing material was irradiated with light at a wavelength of 365 nm and an intensity of 70 mW / cm 2 The polyimide-based temporary fixing material was cured by irradiating it with ultraviolet light for 300 seconds, and 10 mg of the cured product was weighed out in an aluminum pan. The aluminum pan was set in a thermogravimetric and differential thermal analyzer ("STA7200" manufactured by Hitachi High-Tech Science Corporation), and then heated from 25°C to 500°C at a heating rate of 10°C / min in a nitrogen atmosphere. The temperature at which the weight of the cured polyimide-based temporary fixing material had decreased by 5% (5% weight loss temperature) was measured, which was 420°C.

[0120] (Absorbance at wavelength 308 nm) The release PET films were peeled off from both sides of the obtained polyimide-based temporary fixing material, and the obtained polyimide-based temporary fixing material was set on the sample side of a spectrophotometer (Hitachi High-Tech Science Corporation, "U-3900") to measure the absorbance in the thickness direction, which was 0.5 or more. Note that the optical path length at this time was the thickness of the obtained polyimide-based temporary fixing material.

[0121] (Light transmittance at wavelength 405 nm) The release PET films were peeled off from both sides of the obtained polyimide-based temporary fixing material, and the material was set on the sample side of a spectrophotometer (Hitachi High-Tech Science Corporation, "U-3900") to measure the transmittance, which was 1% or more. The optical path length at this time was the thickness of the obtained polyimide-based temporary fixing material.

[0122] (Examples 1 to 5) One of the release PET films was peeled off from the obtained polyimide-based temporary fixing material, and it was attached to a silicon wafer having a diameter of 200 mm and a thickness of 700 μm using a vacuum laminator under the conditions of vacuum, stage temperature of 40° C., and attachment pressure of 0.5 MPa. The attached polyimide-based temporary fixing material was cut to the same size as the silicon wafer. Next, the other release PET film was peeled off, and a glass (manufactured by Schott, "Tempax") having a diameter of 200 mm and a thickness of 600 μm was attached to the surface opposite to the surface attached to the silicon wafer using a pressure lamination device under the conditions of 90° C., attachment pressure of 0.6 MPa, vacuum degree: (SP1) 150 MPa → (SP2) 120 MPa, and bonding time of 360 seconds to obtain a laminate. From the glass side of the obtained laminate, a super high pressure mercury lamp was used to irradiate the glass with a wavelength of 365 nm and an irradiation intensity of 70 mW / cm. 2The temporary fixing material was cured by irradiating ultraviolet rays of 100 nm for 300 seconds to obtain a laminate. The laminate after curing the polyimide-based temporary fixing material was heated from the silicon wafer side on a hot plate at 300 ° C. for 30 minutes. The laminate after heating was irradiated with laser light from the glass side under the conditions shown in Table 1 so as to scan the polyimide-based temporary fixing material in a Z-shape. The laser light was irradiated using a model IPEX-848 manufactured by LightMachinery under the conditions of a wavelength of 308 nm, an average output of 50 W, a frequency of 200 Hz, a beam size of 14 × 1.3 mm, and a pulse width of 20 nsec, and the laser light was irradiated with the irradiation intensity shown in Table 1. The irradiation was performed while ventilating. In addition, a homogenizer, a condenser lens, and a beam splitter were used as a method for flattening the intensity distribution in the irradiation shape of the laser light. Then, the polyimide-based temporary fixing material and the glass were peeled off.

[0123] Comparative Example 1 For the laminate after heating obtained in the same manner as in "Examples 1 to 5" above, the polyimide-based temporary fixing material and the glass were peeled off under conditions of 25°C and a tensile speed of 300 mm / min using a tensile tester (manufactured by Shimadzu Corporation, "AG-IS"). At this time, in order to generate peel initiation points, a wedge-shaped jig was inserted into the side surface of the end of the laminate, and peel initiation points were generated at the interface between the glass support and the polyimide-based temporary fixing material. Thereafter, the silicon wafer side of the laminate was fixed to the stage. Next, a force was applied to the portion of the glass support where the peeling start point had occurred in a direction perpendicular to the adhesive surface to cause peeling. As the peeling progressed, the direction of the peeling force was changed so that the peeling force was applied perpendicular to the plane formed by the end portion on the glass support other than the peeling start point and the portion where the peeling force was applied.

[0124] <Evaluation> The silicon wafer (electronic component) with the polyimide-based temporary fixing material and the glass (support) that were peeled off in the examples and comparative examples were visually observed. Examples 1 to 5 show the results of comparing the degree of influence of laser irradiation conditions. Comparative Example 1 shows the results of a conventional method (mechanical peel). The releasability of the support was evaluated as follows: "O" indicates that the support could be peeled off without damage; and "X" indicates that the support could not be peeled off or was damaged, such as cracked. In addition, the damage prevention properties of the electronic components were evaluated by rating "◯" if the silicon wafer was not damaged and rating "×" if damage was confirmed in the silicon wafer. The results are shown in Table 1.

[0125] [Table 1] [Industrial Applicability]

[0126] According to the present invention, it is possible to provide a method for manufacturing an electronic component that reduces damage to the electronic component and enables the support to be easily peeled off even when the electronic component is subjected to a heat treatment or a treatment involving heat generation.

Claims

1. a support fixing step of fixing the electronic component to the support via a polyimide-based temporary fixing material; a processing step of subjecting the electronic component fixed to the support to a heat treatment or a treatment involving heat generation; a support peeling step of irradiating a laser beam from the support side to peel the support from the electronic component. A method for manufacturing an electronic component, comprising:

2. The polyimide-based temporary fixing material has photocurability, a photocuring step of irradiating light to cure the polyimide-based temporary fixing material after the support fixing step and before the treatment step; The method for manufacturing the electronic component according to claim 1.

3. the polyimide-based temporary fixing material has thermosetting properties, a heat curing step of curing the polyimide-based temporary fixing material by heating after the support fixing step and before the treatment step; The method for manufacturing the electronic component according to claim 1.

4. The wavelength of the laser light is 200 nm or more and 550 nm or less. The method for manufacturing an electronic component according to claim 1, 2 or 3.

5. The irradiation intensity of the laser light is 50 mJ / cm ２ More than 2000mJ / cm ２ 4. The method for manufacturing an electronic component according to claim 1, 2 or 3, wherein:

6. 4. The method for manufacturing an electronic component according to claim 1, wherein the laser light is a CW laser.

7. 4. The method for manufacturing an electronic component according to claim 1, wherein the laser beam is a pulse laser beam.

8. 8. The method for manufacturing an electronic component according to claim 7, wherein the pulse width of the laser light is 100 nsec or less.

9. 4. The method for manufacturing an electronic component according to claim 1, wherein the laser beam is irradiated onto the polyimide-based temporary fixing material in a scanning manner.

10. 4. The method for manufacturing an electronic component according to claim 1, wherein the intensity distribution of the laser light irradiation shape is a Gaussian waveform.

11. 4. The method for manufacturing an electronic component according to claim 1, wherein the intensity distribution of the laser beam in the irradiation shape is flattened.

12. 4. The method for manufacturing an electronic component according to claim 1, wherein the shape of the laser beam to be irradiated is rectangular.

13. 4. The method for manufacturing an electronic component according to claim 1, wherein ventilation is performed during the irradiation of the laser beam.

14. 4. The method for manufacturing an electronic component according to claim 1, wherein the polyimide temporary fixing material has an absorbance of 0.1 or more at a wavelength of 308 nm.

15. 4. The method for manufacturing an electronic component according to claim 1, wherein the polyimide temporary fixing material has a 5% weight loss temperature of 350[deg.] C. or higher after curing.

16. 4. The method for producing an electronic component according to claim 1, wherein the polyimide-based temporary fixing material contains a resin having an imide skeleton in the repeating unit of the main chain.

17. 4. The method for producing an electronic component according to claim 1, wherein the resin having an imide skeleton in a repeating unit of the main chain has a structural unit represented by the following formula (1): 【Chemical 1】 In formula (1), P １ represents an aromatic group; Q １ represents a substituted or unsubstituted linear, branched or cyclic aliphatic group.

18. 4. The method for producing an electronic part according to claim 1, 2 or 3, which contains a compound having a maleimide group.

19. 19. The method for producing an electronic component according to claim 18, wherein the compound having a maleimide group is a bismaleimide compound or a compound having a maleimide group and an imide skeleton in the repeating unit of the main chain.

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