Heat-curable composition, cured object thereof, photo-meltable composition, method for producing structure, method for producing semiconductor device, and polythiol compound

Abstract

Disclosed are a heat-curable composition and a cured object thereof. The heat-curable composition comprises a polythiol compound having a disulfide bond and a hydroxyl group, a cyclic ether compound having a polyether group and two or more cyclic ether groups, a curing accelerator, and a photo-radical generator.

Description

Thermosetting composition and cured product thereof, photofusible composition, method for manufacturing structure, method for manufacturing semiconductor device, and polythiol compound

[0001] The present disclosure relates to a thermosetting composition and a cured product thereof, a photofusible composition, a method for manufacturing a structure, a method for manufacturing a semiconductor device, and a polythiol compound.

[0002] Photo-meltable compositions that can be melted by irradiation with light are used in a variety of applications. For example, Patent Document 1 discloses an image-forming apparatus that includes a recording member having a photo-meltable resin layer made of a photo-meltable composition.

[0003] Patent Document 2 discloses a thermosetting composition that can be melted by light irradiation and can form a cured product (photo-meltable composition) from which the resin component produced by melting by light irradiation can be removed with an aqueous solvent.

[0004] JP 11-190883 A International Publication No. 2023 / 054373

[0005] However, conventional thermosetting compositions tend to have insufficient film-forming properties when applied to a substrate or the like, making it difficult to obtain a good resin film.

[0006] Therefore, a main object of the present disclosure is to provide a thermosetting composition that can be melted by light irradiation, can form a cured product (photo-meltable composition) from which the resin component produced by melting by light irradiation can be removed with an aqueous solvent, and further has excellent film-forming properties.

[0007] The present inventors have conducted extensive research to solve the above problems and have found that film-forming properties can be improved by introducing hydroxyl groups into a polythiol compound, thereby completing the invention of the present disclosure.

[0008] The present disclosure provides thermosetting compositions according to [1] to [4], cured products of the thermosetting compositions according to [5], photofusible compositions according to [6] to [9], methods for manufacturing structures according to

[10] and

[11] , methods for manufacturing semiconductor devices according to

[12] to

[15] , and polythiol compounds according to

[16] to

[19] . [1] A thermosetting composition comprising: a polythiol compound having a disulfide bond and a hydroxyl group; a cyclic ether compound having a polyether group and two or more cyclic ether groups; a curing accelerator; and a photoradical generator. [2] The thermosetting composition according to [1], wherein the polythiol compound has a weight-average molecular weight of 2,000 or more. [3] The thermosetting composition according to [1] or [2], wherein the cyclic ether group is a monovalent group containing an oxirane ring. [4] The thermosetting composition according to any one of [1] to [3], wherein the polythiol compound has a structure represented by formula (XA). [In formula (XA), * represents a bond.] [5] A cured product of the thermosetting composition according to any one of [1] to [4]. [6] A photo-meltable composition comprising: a reaction product of a polythiol compound having a disulfide bond and a hydroxyl group, and a cyclic ether compound having a polyether group and two or more cyclic ether groups; and a photo-radical generator. [7] The photo-meltable composition according to [6], in which the polythiol compound has a weight-average molecular weight of 2,000 or more. [8] The photo-meltable composition according to [6] or [7], in which the cyclic ether group is a monovalent group containing an oxirane ring. [9] The photo-meltable composition according to any one of [6] to [8], in which the polythiol compound has a structure represented by formula (XA). [In formula (XA), * represents a bond.]

[10] A method for manufacturing a structure, comprising: a step of irradiating, with light, at least a portion of a first structure comprising a cured product of the thermosetting composition according to [5]; and a step of developing the light-irradiated first structure with an aqueous solvent to obtain a second structure.

[11] A method for manufacturing a structure, comprising: a step of irradiating, with light, at least a portion of a first structure comprising the photo-meltable composition according to any one of [6] to [8]; and a step of developing the light-irradiated first structure with an aqueous solvent to obtain a second structure.

[12] A method for manufacturing a semiconductor device, comprising: a resin film forming step of forming a resin film containing a cured product of the thermosetting composition described in [5] on a semiconductor wafer, a resin film-attached semiconductor chip fabrication step of dicing the semiconductor wafer on which the resin film has been formed with a dicing blade to fabricate individual semiconductor chips with resin film pieces, and a resin film piece removal step of irradiating light onto the resin film pieces of the semiconductor chips with resin film pieces to remove the resin film pieces from the semiconductor chips with resin film pieces.

[13] The method for manufacturing a semiconductor device described in

[12] , wherein the resin film piece removal step is a step of removing the resin film pieces from the semiconductor chips with resin film pieces using a water-based solvent.

[14] A method for manufacturing a semiconductor device, comprising: a resin film forming step of forming a resin film containing the photo-fusible composition according to any one of [6] to [8] on a semiconductor wafer; a resin film piece-attached semiconductor chip fabrication step of dicing the semiconductor wafer on which the resin film has been formed with a dicing blade to fabricate individual semiconductor chips with resin film pieces; and a resin film piece removal step of irradiating light onto the resin film pieces of the semiconductor chips with resin film pieces to remove the resin film pieces from the semiconductor chips with resin film pieces.

[15] The method for manufacturing a semiconductor device according to

[14] , wherein the resin film piece removal step is a step of removing the resin film pieces from the semiconductor chips with resin film pieces using an aqueous solvent.

[16] A polythiol compound which is a reaction product of a polythiol compound having a disulfide bond and a cyclic ether compound having a polyether group and two or more cyclic ether groups, and which has a hydroxyl group in the molecule.

[17] The polythiol compound according to

[16] , having a weight average molecular weight of 2000 or more.

[18] The polythiol compound according to

[16] or

[17] , wherein the cyclic ether group is a monovalent group containing an oxirane ring.

[19] The polythiol compound according to any one of

[16] to

[18] , having a structure represented by formula (XA): [In formula (XA), * represents a bond.]

[0009] According to the present disclosure, a thermosetting composition is provided that can form a cured product (photo-meltable composition) that can be melted by light irradiation and from which the resin component produced by melting by light irradiation can be removed with an aqueous solvent, and that also has excellent film-forming properties. Also, according to the present disclosure, a cured product of a thermosetting composition and a photo-meltable composition that can be melted by light irradiation and from which the resin component produced by melting by light irradiation can be removed with an aqueous solvent are provided. Also, according to the present disclosure, a method for manufacturing a structure using a cured product of a thermosetting composition or a photo-meltable composition is provided. Also, according to the present disclosure, a method for manufacturing a semiconductor device using a cured product of a thermosetting composition or a photo-meltable composition is provided. Furthermore, according to the present disclosure, a polythiol compound useful for manufacturing a cured product of a thermosetting composition or a photo-meltable composition is provided.

[0010] Fig. 1 is a schematic cross-sectional view for explaining one embodiment of a method for manufacturing a semiconductor device, and Fig. 1(a), Fig. 1(b), Fig. 1(c), and Fig. 1(d) are views showing each step. Fig. 2 is a schematic cross-sectional view for explaining one embodiment of a method for manufacturing a semiconductor device, and Fig. 2(a), Fig. 2(b), Fig. 2(c), and Fig. 2(d) are views showing each step.

[0011] Hereinafter, embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

[0012] In this specification, the term "layer" encompasses not only a structure with a shape formed over the entire surface when observed in a plan view, but also a structure with a shape formed on a portion of the surface. In this specification, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes, as long as the intended effect of the process is achieved. Furthermore, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively.

[0013] In addition, in this specification, the content of each component in a composition means the total amount of the components in the composition when the composition contains multiple substances corresponding to the component, unless otherwise specified. Furthermore, unless otherwise specified, the exemplified materials may be used alone or in combination of two or more.

[0014] Furthermore, in the numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, in the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. "A or B" may include either A or B, or may include both.

[0015] In this specification, "photomeltable" means a property of melting upon irradiation with light. Examples of the melting property include a decrease in elastic modulus, an increase in loss tangent (tan δ), etc. A "photomeltable composition" means a composition that melts upon irradiation with light to form a gel or liquid.

[0016] [Thermosetting composition and cured product thereof] The thermosetting composition of one embodiment contains a polythiol compound having a disulfide bond and a hydroxyl group (hereinafter sometimes referred to as "component (A)"), a cyclic ether compound having a polyether group and two or more cyclic ether groups (hereinafter sometimes referred to as "component (B)"), a curing accelerator (hereinafter sometimes referred to as "component (C)"), and a photoradical generator (hereinafter sometimes referred to as "component (D)").

[0017] The thermosetting composition may be capable of passing through a semi-cured (B-stage) state and then becoming a cured (C-stage) state after a curing treatment. The B-stage refers to an intermediate stage in the reaction of certain thermosetting resins where the material swells when contacted with a certain liquid and softens when heated, but does not completely dissolve or melt. The C-stage refers to the final stage in the reaction of certain thermosetting resins where the material becomes virtually insoluble and infusible.

[0018] Component (A): Polythiol Compound Having a Disulfide Bond and a Hydroxyl Group The component (A) is a compound having a disulfide bond (-S-S-) and a hydroxyl group (-OH) in the molecule, and having two or more thiol groups (-SH). The component (A) may be, for example, a dithiol compound, which is a compound having two thiol groups (-SH). The component (A) may be a high-molecular-weight component of a polymer or oligomer. The compound having two thiol groups (-SH) may be a compound consisting of two thiol groups and a group (first linking group) that contains a disulfide bond and a hydroxyl group and links the two thiol groups.

[0019] Component (A) has one or more (two or more) disulfide bonds in the molecule. The number of disulfide bonds in component (A) may be, for example, 1 to 100, or 2 to 50.

[0020] Component (A) has one or more (two or more) hydroxyl groups in the molecule. The number of hydroxyl groups in component (A) may be, for example, 1 to 100, or 2 to 50.

[0021] Component (A) may be a polythiol compound (e.g., a polymer or oligomer) having a linear or branched linking group and a terminal group, with the linking group containing a disulfide bond and a hydroxyl group. In this case, the terminal group in component (A) may be a thiol group. When component (A) is such a compound, it tends to be easier to form a cured product with excellent photomeltability.

[0022] The component (A) may be, for example, a compound having a disulfide bond and a structure represented by formula (XA) and having two or more thiol groups.

[0023]

[0024] In formula (XA), * represents a bond.

[0025] A compound having a disulfide bond and a structure represented by formula (XA) and having two or more thiol groups can be obtained, for example, by a method comprising a step of reacting a compound represented by formula (A1) with a compound represented by formula (A2). That is, a compound having a disulfide bond and a structure represented by formula (XA) and having two or more thiol groups may be, for example, a reaction product (polymer) of a compound represented by formula (A1) with a compound represented by formula (A2).

[0026]

[0027] In formula (A1), X １ represents a polyether group. １ may be the same or different. n1 represents an integer of 1 or more.

[0028] X １ The polyether group represented by X may be, for example, a polyoxyalkylene group. １ The polyether group represented by the formula: １Ａ -O-X １Ｂ -O-X １Ｃ X may be a group represented by the formula: １Ａ , X １Ｂ , and X １Ｃ may each independently be an alkylene group, and may be an alkylene group having 1 to 2 carbon atoms (for example, a methylene group or an ethylene group). １ Examples of the polyether group represented by the formula: ２ CH ２ -O-CH ２ -O-CH ２ CH ２ - etc.

[0029] n1 may be, for example, 1 or more, 2 or more, 3 or more, or 4 or more, and may be 1000 or less, 500 or less, 200 or less, or 100 or less.

[0030] Examples of commercially available products of the compound represented by formula (A1) include the Thiokol LP series (dithiols having a disulfide bond, manufactured by Toray Fine Chemicals Co., Ltd.).

[0031] In formula (A2), X ２ represents a polyether group. ２ may be the same or different from each other.

[0032] X ２ The polyether group represented by X may be, for example, a polyoxyalkylene group. ２ The polyether group represented by the formula: ２Ａ -[O-X ２Ｂ ] ｎ２ X may be a group represented by the formula: ２Ａ and X ２Ｂ may each independently be an alkylene group, and may be an alkylene group having 1 to 3 carbon atoms (for example, a methylene group, an ethylene group, or a propylene group). ２Ｂ may be the same or different from each other. n2 represents an integer of 1 or more. n2 may be, for example, 1 or more, 2 or more, 3 or more, or 4 or more, and may be 1000 or less, 500 or less, 200 or less, 100 or less, or 50 or less.

[0033] The molecular weight or number average molecular weight (Mn) of the compound represented by formula (A2) may be, for example, 100 to 10,000, 150 to 5,000, or 200 to 2,000. Note that Mn is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[0034] The epoxy equivalent of the compound represented by formula (A2) may be 50 to 2000 g / eq, 80 to 1500 g / eq, or 100 to 1000 g / eq.

[0035] Commercially available products of the compound represented by formula (A2) include, for example, Denacol EX series (EX-850, EX-851, EX-821, EX-830, EX-832, EX-841, EX-861, EX-920, manufactured by Nagase ChemteX Corporation).

[0036] The reaction product (polymer) of the compound represented by formula (A1) and the compound represented by formula (A2) may be, for example, a compound represented by the following formula (X-1).

[0037]

[0038] In formula (X-1), X １ , X ２ , and n1 have the same meanings as above. １ , X ２ and n1 may be the same or different from each other, and n3 represents an integer of 1 or more.

[0039] n3 may be, for example, 1 or more, 2 or more, 3 or more, or 4 or more, and may be 1000 or less, 500 or less, 200 or less, or 100 or less.

[0040] The reaction (polymerization) of the compound represented by formula (A1) and the compound represented by formula (A2) can be carried out by appropriately combining a common dispersing machine such as a stirrer, a mortar and pestle, a three-roll mill, a ball mill, or a bead mill.

[0041] The heating temperature for the reaction (polymerization) of the compound represented by formula (A1) and the compound represented by formula (A2) may be, for example, 0 to 200° C., 30 to 150° C., or 60 to 100° C. The heating time for the reaction (polymerization) of the compound represented by formula (A1) and the compound represented by formula (A2) may be, for example, 0.1 to 168 hours, and may be 72 hours or less, 24 hours or less, 12 hours or less, 6 hours or less, 4 hours or less, 3 hours or less, or 2 hours or less.

[0042] In the reaction (polymerization) of the compound represented by formula (A1) with the compound represented by formula (A2), the thiol equivalent of the compound represented by formula (A1) and the epoxy equivalent of the compound represented by formula (A2) are adjusted so that the resulting reaction product has two or more thiol groups.

[0043] The reaction (polymerization) of the compound represented by formula (A1) with the compound represented by formula (A2) may be carried out in the presence of a curing accelerator (catalytic curing agent), if necessary. Examples of the curing accelerator (catalytic curing agent) include those similar to the component (C) described below.

[0044] The content of the curing accelerator may be 100 ppm by mass or more, 300 ppm by mass or more, or 500 ppm by mass or more, and may be 10,000 ppm by mass or less, 8,000 ppm by mass or less, or 5,000 ppm by mass or less, based on the total amount of the compound represented by Formula (A1) and the compound represented by Formula (A2).

[0045] The weight average molecular weight (Mw) of component (A) may be, for example, 2000 or more. When the Mw of component (A) is 2000 or more, the film-forming properties of the resulting thermosetting composition tend to be even better. As the Mw of component (A) increases, the water developability of the cured product of the thermosetting composition tends to be excellent. The Mw of component (A) may be, for example, 2500 or more, 3000 or more, 3500 or more, or 4000 or more. The upper limit of the Mw of component (A) may be, for example, 15,000 or less, 10,000 or less, or 8,000 or less. Note that Mw is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve with standard polystyrene.

[0046] The content of component (A) may be 40 mass% or more, 50 mass% or more, or 60 mass% or more, and may be 90 mass% or less, 85 mass% or less, or 80 mass% or less, based on the total amount of the thermosetting composition. In this specification, the total amount of the thermosetting composition means the total amount of solids in the thermosetting composition excluding the solvent.

[0047] Component (B): Cyclic Ether Compound Having a Polyether Group and Two or More Cyclic Ether Groups Component (B) is a compound having a polyether group and two or more cyclic ether groups. Component (B) can also be referred to as a compound having a polyether group and two or more cyclic ether rings. When the cured product of the thermosetting composition contains component (B), the resin component produced by melting upon irradiation with light tends to have many polyether groups or hydroxyl groups (derived from cyclic ether groups) and exhibit hydrophilicity, making it possible to remove the resin component with an aqueous solvent. Component (B) may be a high-molecular-weight component of a polymer or oligomer.

[0048] The cyclic ether group of component (B) may be a group obtained by removing one hydrogen atom from a cyclic ether compound. The cyclic ether group of component (B) may also be referred to as a monovalent group containing a cyclic ether ring. Specific examples of cyclic ether compounds include compounds containing an oxirane ring (epoxy ring), compounds containing an oxetane ring, compounds containing a tetrahydrofuran ring, and compounds containing a tetrahydropyran ring. Specific examples of cyclic ether groups include monovalent groups containing an oxirane ring (epoxy ring), monovalent groups containing an oxetane ring, monovalent groups containing a tetrahydrofuran ring, and monovalent groups containing a tetrahydropyran ring. Among these, the cyclic ether group may be a monovalent group containing an oxirane ring (epoxy ring) from the viewpoints of reactivity and ease of availability. That is, component (B) may be an oxirane compound (epoxy compound) having a polyether group and a monovalent group containing two or more oxirane rings (epoxy rings). For example, examples of the monovalent group containing an oxirane ring (epoxy ring) include an oxiranyl group (epoxy group), a glycidyl group, a glycidyl ether group, and an epoxycyclohexyl group.

[0049] The molecular weight or number average molecular weight (Mn) of component (B) may be, for example, 100 to 10,000, 150 to 5,000, or 200 to 2,000. Mn is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[0050] When the cyclic ether group of component (B) is a monovalent group containing an oxirane ring, the epoxy equivalent of component (B) may be 50 to 2000 g / eq, 80 to 1500 g / eq, or 100 to 1000 g / eq.

[0051] The component (B) may be a compound having two cyclic ether groups (hereinafter sometimes referred to as "component (B1)") or a compound having three or more cyclic ether groups (hereinafter sometimes referred to as "component (B2)"). The component (B1) may be a compound consisting of two cyclic ether groups and a group (second linking group) containing a polyether group linking the two cyclic ether groups. The component (B2) may be a compound of the component (B1) that contains a polyether group and has one or more cyclic ether groups as a side chain or substituent of the group linking the two cyclic ether groups. The component (B) may contain both the component (B1) and the component (B2) because this can further shorten the curing time and further improve the photomeltability and water solubility.

[0052] The (B1) component may be a compound (e.g., a polymer or oligomer) having a linear or branched linking group and a terminal group, with the linking group having a polyether group. In this case, the terminal group in the (B1) component may be a cyclic ether group. When the (B) component is the (B1) component, the resin component produced by melting upon light irradiation tends to be easier to remove with an aqueous solvent. The polyether group represented by the linking group may have a substituent such as a hydroxyl group or an alkyl group optionally having a hydroxyl group. The linking group in the (B1) component may contain a polyether group or may consist of a polyether group.

[0053] Examples of the component (B1) include compounds represented by formula (B1-a).

[0054]

[0055] In formula (B1-a), Y １ represents a polyether group. １ and Z ２ each independently represents a cyclic ether group.

[0056] Y １The polyether group represented by Y may be, for example, a polyoxyalkylene group. １ The polyether group represented by the formula: １Ａ -[O-Y １Ｂ ] ｎＹ１ Y may be a group represented by -. １Ａ and Y １Ｂ may each independently be an alkylene group, and may be an alkylene group having 1 to 3 carbon atoms (for example, a methylene group, an ethylene group, or a propylene group). １Ｂ may be the same or different from each other. nY1 represents an integer of 1 or more. nY1 may be, for example, 1 or more, 2 or more, 3 or more, or 4 or more, and may be 1000 or less, 500 or less, 200 or less, or 100 or less.

[0057] Z １ and Z ２ The cyclic ether group represented by the formula (I) may be, for example, a monovalent group containing an oxirane ring.

[0058] Examples of commercially available products of the component (B1) include those similar to the commercially available products of the compound represented by formula (A2).

[0059] The component (B2) may be a compound of the component (B1) that contains a polyether group and has one or more cyclic ether groups as side chains or substituents of the group connecting the two cyclic ether groups.

[0060] Commercially available products of the component (B2) include, for example, the Denacol EX series (EX-614B, EX-313, EX-512, EX-521, manufactured by Nagase ChemteX Corporation).

[0061] The content of the component (B) (total of the component (B1) and the component (B2)) may be 1 mass % or more, 2 mass % or more, or 3 mass % or more, and may be 20 mass % or less, 15 mass % or less, or 10 mass % or less, based on the total amount of the thermosetting composition.

[0062] The mass ratio of the content of the component (B2) to the content of the component (B) (the total of the component (B1) and the component (B2)) (the content (mass) of the component (B2) / the content (mass) of the component (B) (the total of the component (B1) and the component (B2))) may be 0.5 or more, 0.6 or more, 0.7 or more, or 0.8 or more, and may be 1 or less.

[0063] The equivalent ratio of the cyclic ether groups of component (B) to the thiol groups of component (A) (cyclic ether equivalent of component (B) / thiol equivalent of component (A)) may be, for example, 0.5 to 2.5. When this equivalent ratio is 0.5 or more, the water solubility of the thermosetting composition tends to be further improved, and when this equivalent ratio is 2.5 or less, the photomeltability tends to be further improved. This equivalent ratio may be 0.7 or more, 0.8 or more, or 0.9 or more, or may be 2.2 or less, 2.0 or less, 1.8 or less, 1.6 or less, or 1.4 or less.

[0064] Component (C): Curing Accelerator Component (C) is a component for accelerating the (curing) reaction of components (A) and (B), and includes a component that functions as a catalyst for the curing reaction (catalytic curing agent). Examples of component (C) include amine compounds, imidazole derivatives, quaternary ammonium salts, organic metal salts, and phosphorus compounds.

[0065] Examples of the amine compound include dicyandiamide, trimethylamine, triethylamine, tripropylamine, tributylamine, tri-n-octylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, dimethyl-n-octylamine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, benzyldimethylamine, 4-methyl-N,N-dimethylbenzylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 4-dimethylaminopyridine.

[0066] Examples of the imidazole derivatives include 1-(1-cyanomethyl)-2-ethyl-4-methyl-1H-imidazole, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4,5-triphenylimidazole, 1-benzyl-2-imidazole, 1,2-dimethylimidazole, and 1-benzyl-2-phenylimidazole.

[0067] Examples of quaternary ammonium salts include tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, benzyltrimethylammonium bromide, benzyltriethylammonium bromide, tetramethylammonium iodide, tetraethylammonium iodide, tetrabutylammonium iodide, and benzyltributylammonium iodide.

[0068] Examples of the organic metal salt include zinc(II) bis(2,4-pentanedionato), zinc octylate, zinc naphthenate, cobalt naphthenate, copper naphthenate, iron acetylacetonate, nickel octylate, and manganese octylate.

[0069] Examples of the phosphorus compound include tetraphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, triphenylphosphine, tri-p-tolylphosphine, tris(4-chlorophenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(2,6-dimethoxyphenyl)phosphine, triphenylphosphine triphenylborane, tetraphenylphosphonium dicyanamide, and tetraphenylphosphonium tetra(4-methylphenyl)borate.

[0070] The content of component (C) may be 0.01 mass% or more, 0.1 mass% or more, or 0.5 mass% or more, and may be 10 mass% or less, 5 mass% or less, or 2 mass% or less, based on the total amount of the thermosetting composition.

[0071] Component (D): Photoradical Generator Component (D) is a component that generates radicals upon light irradiation in the cured product of the thermosetting composition. Examples of component (D) include hydrogen abstraction-type photoradical generators that generate radicals by abstracting hydrogen from other molecules upon light irradiation, and intramolecular cleavage-type photoradical generators that photocleave themselves upon light irradiation to generate two radicals. Component (D) may be an intramolecular cleavage-type photoradical generator because the (photofusion) reaction easily proceeds.

[0072] Examples of the hydrogen abstraction type photoradical generator include hexaarylbisimidazole (HABI) compounds, benzophenone compounds, thioxanthone compounds, fluorenone compounds, and α-diketone compounds.

[0073] Examples of HABI compounds include 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole (e.g., 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole), 2,2'-bis(o-bromophenyl)-4,4',5,5'-tetraphenylbiimidazole, and 2,2'-bis(o,p-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole. 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetra(m-methoxyphenyl)biimidazole, 2,2'-bis(o,o'-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(o-nitrophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(o-methylphenyl)-4,4',5,5'-tetraphenylbiimidazole, and the like.

[0074] Examples of the benzophenone compound include 4,4'-bis(dimethylamino)benzophenone and 4,4'-bis(diethylamino)benzophenone.

[0075] Examples of thioxanthone compounds include thioxanthone, 2-isopropylthioxanthone, 2-dodecylthioxanthone, 2-cyclohexylthioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 1-phenoxythioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxyethoxycarbonyl)-thioxanthone, 4-butoxycarbonylthioxanthone, 3-butoxycarbonyl-7-methylthioxanthone, 3,4-di-[2-(2-methoxyethoxy)-ethoxycarbonyl]-thioxanthone, 2-chlorothioxanthone, and 1-ethoxycarbonyl 1-ethoxycarbonyl-3-chlorothioxanthone, 1-chloro-4-n-propoxythioxanthone, 2-methyl-6-dimethoxymethyl-thioxanthone, 2-methyl-6-(1,1-dimethoxybenzyl)-thioxanthone, 6-ethoxycarbonyl-2-methoxy-thioxanthone, 6-ethoxycarbonyl-2-methylthioxanthone, 1-ethoxycarbonyl-3-(1-methyl-1-morpholinoethyl)-thioxanthone, 2-morpholinomethylthioxanthone, 2-methyl-6-morpholinomethylthioxanthone, thioxanthone-2-carboxylic acid polyethylene glycol ester, and the like.

[0076] Examples of the fluorenone compound include 9-fluorenone, 3,4-benzo-9-fluorenone, 2-dimethylamino-9-fluorenone, 2-methoxy-9-fluorenone, 2-chloro-9-fluorenone, 2,7-dichloro-9-fluorenone, 2-bromo-9-fluorenone, 2,7-dibromo-9-fluorenone, 2-nitro-9-fluorenone, and 2-acetoxy-9-fluorenone.

[0077] Examples of the α-diketone compound include benzil (a compound also known as diphenylethanedione or dibenzoyl).

[0078] Examples of the intramolecular cleavage type photoradical generator include a benzyl ketal-based photoradical generator, an α-aminoalkylphenone-based photoradical generator, an α-hydroxyalkylphenone-based photoradical generator, an α-hydroxyacetophenone-based photoradical generator, and an acylphosphine oxide-based photoradical generator.

[0079] Examples of benzyl ketal photoradical generators include 2,2-dimethoxy-1,2-diphenylethan-1-one (Omnirad 651).

[0080] Examples of α-aminoalkylphenone photoradical generators include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (Omnirad369), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (Omnirad907), and 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholino-4-yl-phenyl)-butan-1-one (Omnirad379EG).

[0081] Examples of the α-hydroxyalkylphenone-based photoradical generator include 1-hydroxy-cyclohexyl-phenyl-ketone (Omnirad 184).

[0082] Examples of the α-hydroxyacetophenone-based photoradical generator include 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one (Omnirad 127) and 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Omnirad 1173).

[0083] Examples of acylphosphine oxide photoradical generators include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (OmniradTPO 3 H), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Omnirad 819), and the like.

[0084] The content of component (D) may be 1 mass % or more, 5 mass % or more, or 10 mass % or more, and may be 30 mass % or less, 25 mass % or less, or 20 mass % or less, based on the total amount of the thermosetting composition.

[0085] The thermosetting composition may further contain other components in addition to the components (A), (B), (C), and (D). Examples of other components include tackifiers such as plasticizers and tackifiers, adhesion improvers such as antioxidants, leuco dyes, sensitizers, and coupling agents, and additives such as polymerization inhibitors, light stabilizers, antifoaming agents, fillers, chain transfer agents, thixotropy-imparting agents, flame retardants, mold release agents, surfactants, lubricants, and antistatic agents. Known additives can be used. The content of these other components may be 0 to 95% by mass, 0.01 to 50% by mass, or 0.1 to 10% by mass, based on the total amount of the thermosetting composition.

[0086] The thermosetting composition may be diluted with a solvent and used as a varnish. Examples of the solvent include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; aliphatic hydrocarbons such as hexane and heptane; cyclic alkanes such as methylcyclohexane; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; ether esters such as methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, and propylene glycol monomethyl ether acetate (PGMEA); and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone (NMP). The solid content of the varnish, that is, the total content of the varnish other than the solvent, may be 10 to 95% by mass, or 15 to 80% by mass, or 20 to 60% by mass, based on the total amount of the varnish.

[0087] The thermosetting composition can be prepared, for example, by a method comprising a step of mixing or kneading components (A), (B), (C), and (D), as well as other components added as necessary. The mixing and kneading can be carried out using an appropriate combination of dispersing machines such as a conventional mixer, a mortar and pestle mixer, a triple-roll mill, a ball mill, or a bead mill.

[0088] The thermosetting composition can be cured by heating. Heating the thermosetting composition promotes a curing reaction between the (A) and (B) components. During this process, the (C) component may be consumed. The reaction product of the (A) and (B) components may be, for example, a compound (polymer) having a structure represented by formula (XB). Meanwhile, the (D) component is less involved in the curing reaction, and the cured product of the thermosetting composition may contain the reaction product of the (A) and (B) components and the (D) component. The cured product of the thermosetting composition may be a water-insoluble resin that is depolymerized by light irradiation to form a water-soluble gel or liquid.

[0089]

[0090] In formula (XB), X represents a first linking group (for example, a group represented by formula (XB-1)), and Y represents a second linking group (for example, a polyether group). m represents an integer of 1 or more. m may be, for example, 5 or more, 10 or more, 20 or more, or 30 or more. * represents a bond.

[0091]

[0092] In formula (XB-1), X １ and n1 have the same meanings as above. １ and n1 may be the same or different from each other.

[0093] The heating temperature when the thermosetting composition is heated may be, for example, 0 to 200° C., 30 to 150° C., or 60 to 100° C. The heating (holding) time when the thermosetting composition is heated may be, for example, 0.1 to 168 hours, and may be 72 hours or less, 24 hours or less, 12 hours or less, 6 hours or less, 4 hours or less, 3 hours or less, or 2 hours or less.

[0094] A resin film containing a cured product of a thermosetting composition can be obtained, for example, by applying a varnish of the thermosetting composition containing the thermosetting composition and a solvent using a spin coater or the like to form a coating film, removing the solvent from the formed coating film, and then curing the thermosetting composition. Because the thermosetting composition has excellent film-forming properties, its use tends to make it easier to obtain a uniform resin film.

[0095] The varnish of the thermosetting composition may be in a state in which the reaction of the components (A) and (B) contained in the thermosetting composition has progressed partially (a state in which the varnish contains a reaction product of the components (A) and (B)). When the varnish of the thermosetting composition is in a state in which the reaction of the components (A) and (B) has progressed partially, film formability tends to be further improved.

[0096] The conditions for removing the solvent are not particularly limited as long as the solvent used is sufficiently evaporated, but may be, for example, 50 to 120° C. and 1 to 15 minutes.

[0097] The conditions for curing the thermosetting composition may be, for example, 50 to 150° C. and 1 minute to 48 hours.

[0098] The cured product of the thermosetting composition can be molded into various shapes. For example, the cured product of the thermosetting composition can be molded into a membrane (film) and used as a film. For example, the cured product of the thermosetting composition can be molded into a block and used as a block. The method for molding into a membrane (film) or block is not particularly limited, and known methods can be applied.

[0099] The cured product of the thermosetting composition has the property of melting when irradiated with light. The light used for irradiation may contain, for example, light with a wavelength of 405 nm or 365 nm. The light used for irradiation may be, for example, ultraviolet light or visible light. By irradiating with such light, the cured product of the thermosetting composition can be efficiently melted. The irradiation dose (exposure dose) of the light irradiation is, for example, 1000 mJ / cm. ２ The irradiation dose may be, for example, 3000 mJ / cm ２ Above, 5000mJ / cm ２ or more, or 10,000 mJ / cm ２ or more, 100,000 mJ / cm ２ Below, 80000mJ / cm ２ or less, or 60,000 mJ / cm ２ In this specification, the amount of irradiation is defined as the illuminance (mW / cm ２ ) and the irradiation time (seconds). Light irradiation may be performed directly on the object to be irradiated, or may be performed through glass or the like. The light source used for light irradiation is not particularly limited, and examples thereof include an LED lamp, a mercury lamp (low pressure, high pressure, ultra-high pressure, etc.), a metal halide lamp, an excimer lamp, a xenon lamp, etc. Among these, the light source used for light irradiation may be an LED lamp, a mercury lamp, or a metal halide lamp.

[0100] Irradiating a cured product of the thermosetting composition with light cleaves the disulfide bond (-S-S-) in the reaction product of components (A) and (B). This reduces the molecular weight of the reaction product of components (A) and (B) and can result in a liquid (liquid state). Because the cured product of the thermosetting composition melts upon irradiation with light, it can also be referred to as a photomeltable composition. The cured product of the thermosetting composition (photomeltable composition) can contain the reaction product of components (A) and (B) and component (D). The cured product of the thermosetting composition (photomeltable composition) can be a water-insoluble resin that is reduced in molecular weight upon irradiation with light, resulting in a water-soluble gel or liquid.

[0101] The mechanism by which a cured product of a thermosetting composition undergoes photo-melting is not clear, but possible mechanisms include, for example, the following. However, the mechanism is not limited to these. When a cured product of a thermosetting composition is irradiated with light, the disulfide bond in the reaction product of components (A) and (B) is decomposed (cleaved), generating a thiyl radical. If component (D) is present in the cured product of the thermosetting composition, the thiyl radical reacts with component (D), and the thiyl radical is capped by component (D). This may result in a lower molecular weight of the reaction product of components (A) and (B) that has a disulfide bond, causing the cured product of the thermosetting composition to undergo photo-melting. Another possible mechanism is that photoinduced radicals originating from component (D) react directly with disulfide bonds, forming photoinduced radical-thioether bonds and generating thiyl radicals, which then react with other photoinduced radicals, resulting in a low molecular weight reaction product of the disulfide bond-containing reaction product of components (A) and (B), thereby softening the cured product of the thermosetting composition. The reaction in which disulfide bonds are cleaved can be considered an irreversible reaction.

[0102] The resin component derived from the reaction product of components (A) and (B) that is produced by melting a cured product of the thermosetting composition (photo-meltable composition) upon irradiation with light has many polyether groups or hydroxyl groups and tends to exhibit hydrophilicity, making it possible to remove the resin component with an aqueous solvent. Examples of aqueous solvents include water and mixed solvents of water and hydrophilic organic solvents. In mixed solvents of water and hydrophilic organic solvents, the proportion of water can be, for example, 80% by mass or more. The aqueous solvent may contain, for example, a pH adjuster.

[0103] Examples of water include tap water, natural water, purified water, distilled water, ion-exchanged water, pure water, and ultrapure water (such as Milli-Q water). Milli-Q water refers to ultrapure water obtained using a Milli-Q water production system manufactured by Merck Millipore (Merck). Since the water has reduced impurities, it may be purified water, distilled water, ion-exchanged water, pure water, or ultrapure water.

[0104] Examples of the hydrophilic organic solvent include alcohols such as methanol, ethanol, 2-propanol, and 1,2-propanediol; and glycol ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethyl cellosolve, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, butyl cellosolve, ethylene glycol monoisobutyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and dipropylene glycol monomethyl ether.

[0105] Examples of pH adjusters include inorganic acids, inorganic bases, organic acids, and organic bases. Examples of inorganic acids include nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, and boric acid. Examples of inorganic bases include sodium hydroxide, potassium hydroxide, and calcium hydroxide. Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, acrylic acid, benzoic acid, and picolinic acid. Examples of organic bases include primary amines, secondary amines, tertiary amines, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and imidazole-based compounds.

[0106] The cured product of the thermosetting composition of the present embodiment can be used for applications such as temporary fixing adhesives, medical adhesives, easily dismantled adhesives, materials for reflow sheets, photoresist materials (photoresists that can be developed without alkali), and materials for 3D printers.

[0107] [Photo-meltable composition] One embodiment of the photo-meltable composition contains a reaction product of the components (A) and (B), and the component (D). The photo-meltable composition may be a cured product of the above-mentioned thermosetting composition. The types and preferred aspects of the components (A), (B), and (D) are the same as those of the components (A), (B), and (D) of the thermosetting composition and its cured product. Therefore, redundant explanations will be omitted here.

[0108] The content of the reaction product of components (A) and (B) may be 60% by mass or more, 65% by mass or more, 70% by mass or more, or 75% by mass or more, based on the total amount of the photo-meltable composition, and may be 99% by mass or less, 95% by mass or less, 90% by mass or less, or 85% by mass or less. In this specification, the total amount of the photo-meltable composition means the total amount of solids in the photo-meltable composition excluding the solvent.

[0109] The content of component (D) may be 1 mass % or more, 5 mass % or more, 10 mass % or more, or 15 mass % or more, based on the total amount of the photo-meltable composition, and may be 40 mass % or less, 35 mass % or less, 30 mass % or less, or 25 mass % or less.

[0110] [Method for manufacturing a structure] A method for manufacturing a structure in one embodiment includes the steps of irradiating light onto at least a portion of a first structure containing the cured product of the thermosetting composition or the photo-meltable composition, and developing the light-irradiated first structure with an aqueous solvent to obtain a second structure. The method for manufacturing a structure is a method for manufacturing a second structure. The second structure is a structure in which the cured product of the thermosetting composition or the photo-meltable composition in the light-irradiated portion (part) of the first structure has been removed, and can be a structure having a recess of a desired shape.

[0111] The first structure is a cured product of the thermosetting composition or the photo-fusible composition molded into various shapes. The first structure may have a shape such as a membrane (film) or a block, and may be a film, a block, or the like. The method for molding the first structure is not particularly limited, and known methods can be applied.

[0112] The type of light, the amount of light irradiation, the light source used for light irradiation, etc. when irradiating the first structure with light may be the same as those described above.

[0113] In the case of a cured product of a thermosetting composition or a photo-fusible composition, similar to a positive photoresist, the areas irradiated with light are removed with an aqueous solvent by development, while the areas not irradiated with light remain, thereby forming recesses of a desired shape. When irradiating the first structure with light, for example, a photomask or the like can be used to selectively irradiate predetermined areas (areas where recesses are to be formed).

[0114] The first structure that has been irradiated with light is developed with an aqueous solvent, thereby obtaining a second structure in which the cured product of the thermosetting composition or the photo-meltable composition in the irradiated portion (part) of the first structure has been removed. The aqueous solvent may be the same as described above.

[0115] The second structure may be a film, a block, etc. having a recess of a desired shape. Specific examples of the second structure include a semiconductor resist pattern, a culture substrate, etc.

[0116] [Method for Manufacturing Semiconductor Device] One embodiment of the method for manufacturing a semiconductor device relates to a method for manufacturing a semiconductor device that includes a step of forming a resin film (protective film) on a semiconductor wafer. The method for manufacturing a semiconductor device includes a resin film (protective film) forming step, a resin film (protective film) piece-attached semiconductor chip fabrication step, and a resin film (protective film) piece removal step. Figures 1 and 2 are schematic cross-sectional views illustrating one embodiment of the method for manufacturing a semiconductor device.

[0117] <Resin Film Forming Step> In this step, a resin film 3 containing a cured product of the thermosetting composition or the photo-fusible composition is formed on a semiconductor wafer 1. The resin film 3 can act as a protective film that prevents fine cuttings (debris) generated by cutting the semiconductor wafer from adhering to the circuit-forming surface of the semiconductor wafer. The cured product of the thermosetting composition or the resin film containing the photo-fusible composition is useful as a protective film (protective film for blade dicing) when dicing a semiconductor wafer with a dicing blade.

[0118] The resin film forming step may include, for example, a step of preparing a semiconductor wafer 1 (see FIG. 1( a)) and a step of forming a resin film 3 containing a cured product of the above-mentioned thermosetting composition or the above-mentioned photo-fusible composition on the semiconductor wafer 1 (see FIG. 1( b)).

[0119] Examples of the semiconductor wafer 1 include single crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide. The semiconductor wafer 1 may have a surface on which circuits are formed.

[0120] The thickness of the semiconductor wafer 1 may be, for example, 10 to 1000 μm, 20 to 900 μm, or 30 to 800 μm.

[0121] The method for forming the resin film 3 may be the same as the method for forming the resin film containing the cured product of the thermosetting composition described above.

[0122] The resin film 3 may be in a cured (C-stage) state. The thickness of the resin film 3 may be, for example, 1 to 1000 μm, 2 to 500 μm, or 3 to 200 μm.

[0123] In this manner, a resin film 3 containing the cured product of the thermosetting composition or the photo-fusible composition can be formed on the semiconductor wafer 1 .

[0124] <Step of Producing Semiconductor Chips with Resin Film Pieces> In this step, the semiconductor wafer 1 on which the resin film 3 is formed is diced with a dicing blade 9 to produce individual semiconductor chips 7 with resin film pieces.

[0125] The process for producing a semiconductor chip with a resin film piece may include, for example, a step of preparing a laminate 10 having a dicing tape 5, a semiconductor wafer 1, and a resin film 3 in this order (see FIG. 1(c)), and a step of dicing at least the semiconductor wafer 1 and the resin film 3 in the laminate 10 with a dicing blade 9 to obtain individual semiconductor chips 7 with a resin film piece (see FIG. 1(d)).

[0126] Examples of the dicing tape 5 include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. The dicing tape may also be subjected to surface treatments such as primer coating, UV treatment, corona discharge treatment, polishing, and etching, as needed. The dicing tape may also be adhesive. Such a dicing tape may be the above-mentioned plastic film to which adhesive properties have been imparted, or may be the above-mentioned plastic film on one side of which an adhesive layer has been provided. The adhesive layer may be made of a UV-curable or non-UV-curable pressure-sensitive adhesive. There are no particular limitations on the adhesive layer, as long as it has sufficient adhesive strength to prevent the semiconductor element from scattering during dicing, and conventionally known adhesives can be used.

[0127] The thickness of the dicing tape 5 may be, for example, 10 to 1000 μm, 30 to 500 μm, or 50 to 300 μm.

[0128] The laminate 10 can be obtained by attaching a dicing tape 5 to the semiconductor wafer 1 on which the resin film 3 is formed.

[0129] Next, at least the semiconductor wafer 1 and the resin film 3 (and also a part of the dicing tape 5) in the laminate 10 are diced with a dicing blade 9 to separate them into individual pieces. Dicing with the dicing blade 9 can be performed using a commercially available device. Dicing with the dicing blade 9 is performed, for example, on the semiconductor wafer 1 and the resin film 3 in a cutting pattern that forms a grid shape in a plan view.

[0130] Dicing with the dicing blade 9 is usually performed while spraying cooling water (cutting water) on the contact points between the semiconductor wafer 1 or resin film 3 and the dicing blade 9, from the viewpoint of suppressing temperature rise at these contact points. Since the resin film 3 is a water-insoluble resin, such as a cured product of the thermosetting composition or the photo-fusible composition, dissolution of the resin film by the cooling water (cutting water) can be sufficiently suppressed, and residues of the cutting material (debris) can be sufficiently prevented from adhering to the circuit-forming surface of the semiconductor wafer.

[0131] In this manner, the semiconductor wafer 1 and the resin film 3 are individually divided, and a semiconductor chip 7 with a resin film piece, which has a semiconductor chip 1a and a resin film piece 3a, can be obtained.

[0132] The shape of the semiconductor chip 1a in plan view may be, for example, a square or a rectangle. The area of ​​the semiconductor chip 1a is, for example, 1 to 250 mm ２ , 4 to 200 mm ２ , or 9 to 150 mm ２ The length of one side of the semiconductor chip 1a may be 1 mm or more, 2 mm or more, or 3 mm or more, and may be 20 mm or less, 18 mm or less, or 15 mm or less. The thickness of the semiconductor chip 1a may be the same as or smaller than the thickness of the semiconductor wafer 1.

[0133] <Resin Film Piece Removal Process> In this process, light A is irradiated onto the resin film pieces 3a of the semiconductor chip 7 with resin film pieces, and the resin film pieces 3a are removed from the semiconductor chip 7 with resin film pieces (see FIG. 2(a)). The cured product of the thermosetting composition or the photo-meltable composition contained in the resin film pieces 3a is depolymerized by irradiating with light A, giving a gel-like or liquid substance, which makes it possible to easily remove the resin film pieces 3a from the semiconductor chip 7 with resin film pieces.

[0134] The type of light, the amount of light irradiation, the light source used for light irradiation, etc. when the resin film piece 3a is irradiated with light A may be the same as those described above.

[0135] In one embodiment, the resin film piece removal step may be a step of removing the resin film pieces 3a from the resin film piece-attached semiconductor chip 7 using an aqueous solvent. The photo-fusible resin contained in the resin film pieces 3a is depolymerized by irradiating it with light to form a gel or liquid, so the resin film pieces 3a can be sufficiently removed by washing with an aqueous solvent. The aqueous solvent may be the same as described above.

[0136] In one embodiment, the resin film piece removal step may be a step of irradiating light A onto the resin film pieces 3a of the semiconductor chip 7 with resin film pieces in an aqueous solvent 11 (see FIG. 2(b)). The cured product of the thermosetting composition or the photo-meltable composition contained in the resin film pieces 3a is depolymerized by irradiation with light, thereby forming a gel or liquid substance. Therefore, by irradiating light A onto the resin film pieces 3a in the aqueous solvent 11, the gel or liquid substance flows out into the aqueous solvent 11, allowing the resin film pieces 3a to be efficiently removed.

[0137] In this way, a plurality of semiconductor chips 1a can be obtained from the semiconductor wafer 1, with the adhesion of cuttings (debris) being sufficiently suppressed (see FIG. 2(c)).

[0138] The method for manufacturing a semiconductor device of this embodiment may further include an ultraviolet irradiation step of irradiating ultraviolet rays onto the adhesive layer of the dicing tape 5, a pick-up step of picking up the semiconductor chip 1a, a semiconductor chip bonding step of thermocompressing the picked-up semiconductor chip 1a and the support member 13 via an adhesive layer 15 (such as a die bonding film), and a heat curing step of heat curing the adhesive layer 15.

[0139] <Ultraviolet Light Irradiation Step> When the adhesive layer of the dicing tape 5 is made of an ultraviolet-curable pressure-sensitive adhesive, the method for manufacturing a semiconductor device may include an ultraviolet light irradiation step. In this step, the adhesive layer is irradiated with ultraviolet light. The wavelength of the ultraviolet light may be 200 to 400 nm. The ultraviolet light irradiation conditions are an illuminance and an irradiation amount of 30 to 240 mW / cm. ２ and 50 to 500 mJ / cm ２ may be in the range of

[0140] <Pickup Step> In this step, the individual semiconductor chips 1a are spaced apart from one another, and the semiconductor chips 1a pushed up by needles from the dicing tape 5 side are picked up from the dicing tape 5 by suction with a suction collet.

[0141] The ultraviolet irradiation step and the pick-up step may be performed after the resin film piece removal step, or may be performed before the resin film piece removal step.

[0142] <Semiconductor Chip Bonding Step> In this step, the picked-up semiconductor chip 1a is bonded to the support member 13 by thermocompression bonding via an adhesive layer 15 (such as a die bonding film). The die bonding film may be a die bonding film used in the relevant field. Multiple semiconductor chips 1a may be bonded to the support member 13.

[0143] The heating temperature in the thermocompression bonding may be, for example, 80 to 160° C. The load in the thermocompression bonding may be, for example, 5 to 15 N. The heating time in the thermocompression bonding may be, for example, 0.5 to 20 seconds.

[0144] <Thermal Curing Step> In this step, the adhesive layer 15 is thermally cured. The heating temperature can be appropriately changed depending on the constituent components of the die bonding film. The heating temperature may be, for example, 60 to 200°C, 90 to 190°C, or 120 to 180°C. The heating time may be 30 minutes to 5 hours, 1 to 3 hours, or 2 to 3 hours. The temperature or pressure may be changed stepwise during the heating step.

[0145] In this way, a semiconductor device 20 (see FIG. 2(d)) can be manufactured, which includes a semiconductor chip 1a, a support member 13 on which the semiconductor chip 1a is mounted, and an adhesive layer 15 provided between the semiconductor chip 1a and the support member 13 and bonding the semiconductor chip 1a and the support member 13 together.

[0146] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples.

[0147] [Synthesis of Polythiol Compound] <Preparation of Raw Materials> The following raw materials were prepared. Polythiol compound having a disulfide bond X-1: Thiokol LP-3 (dithiol compound, manufactured by Toray Fine Chemicals Co., Ltd., weight average molecular weight: 1000) Cyclic ether compound having a polyether group and two or more cyclic ether groups X-2: Denacol EX-861 (oxirane compound, number of oxirane rings: 2, manufactured by Nagase ChemteX Corporation, epoxy equivalent: 551 g / eq) Curing accelerator X-3: UCAT SA-1 (salt compound of 1,8-diazabicyclo[5.4.0]undec-7-ene, manufactured by San-Apro Co., Ltd.)

[0148] Example 1-1 Synthesis of Polythiol Compound 129.5 g of (X-1) and 70.1 g of (X-2) were weighed into a flask so that the equivalent ratio of thiol groups to epoxy groups was 2:1. The mixture was heated to 100°C while stirring under a nitrogen atmosphere with a flow rate of 50 mL / min and a stirring impeller rotation speed of 200 rpm. Once the contents of the flask stabilized at 100°C, (X-3) was added. The amount of (X-3) added was adjusted to 2000 ppm based on the total amount of (X-1) and (X-2). While maintaining the temperature at 100°C, the contents of the flask were sampled as needed to measure the thiol concentration. The reaction was continued until the thiol concentration reached 50% of the amount added, which was set as the end point, to obtain dithiol compound (A-1) of Example 1-1. The weight-average molecular weight (Mw) of dithiol compound (A-1) of Example 1-1 was 3000.

[0149] Mw was measured by gel permeation chromatography (GPC) and calculated by conversion using a calibration curve of standard polystyrene. The GPC conditions are as follows: Measuring device: Shodex (registered trademark) GPC-101 (manufactured by Resonac Co., Ltd.) Detector: Differential refractometer Shodex RI-71S (manufactured by Resonac Co., Ltd.) Column: Shodex LF-804 + LF-804 (manufactured by Resonac Co., Ltd.) Column temperature: 40°C Eluent: tetrahydrofuran (THF) Flow rate: 1 mL / min

[0150] Example 1-2 Synthesis of Polythiol Compound 115.9 g of (X-1) and 83.7 g of (X-2) were weighed into a flask so that the equivalent ratio of thiol groups to epoxy groups was 3:2. Under a nitrogen atmosphere with a flow rate of 50 mL / min, the mixture was heated to 100°C while stirring at a stirring impeller rotation speed of 200 rpm. Once the contents of the flask stabilized at 100°C, (X-3) was added. The amount of (X-3) added was adjusted to 2000 ppm based on the total amount of (X-1) and (X-2). While maintaining the flask contents at 100°C, the flask contents were sampled as needed to measure the thiol concentration. The reaction was continued until the thiol concentration reached 33% of the input amount, which was set as the end point, to obtain dithiol compound (A-2) of Example 1-2. The weight-average molecular weight (Mw) of dithiol compound (A-2) of Example 1-2 was 5000.

[0151] Example 1-3 Synthesis of Polythiol Compound 55.2 g of (X-1) and 43.6 g of (X-2) were weighed into a flask so that the equivalent ratio of thiol groups to epoxy groups was 7:5. The mixture was heated to 100°C while stirring under a nitrogen atmosphere with a flow rate of 50 mL / min and a stirring impeller rotation speed of 200 rpm. Once the contents of the flask stabilized at 100°C, (X-3) was added. The amount of (X-3) added was adjusted to 2000 ppm based on the total amount of (X-1) and (X-2). While maintaining the temperature at 100°C, the contents of the flask were sampled as needed to measure the thiol concentration. The reaction was continued until the thiol concentration reached 29% of the amount added, which was set as the end point, to obtain dithiol compound (A-3) of Example 1-3. The weight-average molecular weight (Mw) of dithiol compound (A-3) of Example 1-3 was 7000.

[0152] [Preparation of thermosetting composition varnish] <Preparation of raw materials> The following raw materials were prepared. Component (A): Polythiol compound having a disulfide bond and a hydroxyl group A-1: ​​Dithiol compound (A-1) of Example 1-1 A-2: Dithiol compound (A-2) of Example 1-2 A-3: Dithiol compound (A-3) of Example 1-3 Component (a): Polythiol compound having a disulfide bond and no hydroxyl group a-1: Thiokol LP-3 (dithiol compound, manufactured by Toray Fine Chemicals Co., Ltd., weight average molecular weight: 1000) Component (B): Cyclic ether compound having a polyether group and two or more cyclic ether groups B-1: Denacol EX-861 (oxirane compound, number of oxirane rings: 2, manufactured by Nagase ChemteX Corporation, epoxy equivalent: 551 g / eq) B-2: Denacol EX-614B (oxirane compound, number of oxirane rings: 4, manufactured by Nagase ChemteX Corporation, epoxy equivalent: 167 g / eq) (C) component: curing accelerator C-1: UCAT SA-1 (salt compound of 1,8-diazabicyclo[5.4.0]undec-7-ene, manufactured by San-Apro Co., Ltd.) (D) component: photoradical generator D-1: Omnirad 379EG (2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholino-4-yl-phenyl)-butan-1-one, manufactured by IGM Resins B.V.) (E) component: solvent E-1: propylene glycol monomethyl ether acetate (PGMEA)

[0153] Examples 2-1 to 2-3 and Comparative Example 2-1 Preparation of Thermosetting Composition Varnish Component (A), component (a), component (B), and component (D) were added to an ointment jar in the amounts (parts by mass) of the components listed in Table 1, and the mixture was mixed at 2,000 rpm for 90 seconds using a rotary mixer (Thinky Corporation, product name: Awatori Rentaro ARE-310), followed by preheating at 100°C for 30 minutes. After cooling, the mixture in the ointment jar was transferred to a screw bottle and diluted with component (E) to a solids content of 50% by mass. The diluted mixture was mixed using a vortex mixer, and once the solids were uniformly dissolved, component (C) was added in the amount (parts by mass) of the components listed in Table 1 to obtain thermosetting composition varnishes of Examples 2-1 to 2-3 and Comparative Example 2-1.

[0154] [Evaluation of Thermosetting Compositions] (Film Formability Test) The film formability on silicon wafers was evaluated using the varnishes of the thermosetting compositions of Examples 2-1 to 2-3 and Comparative Example 2-1. A silicon wafer (6 inches, thickness: 625 μm) was fixed to a spin coater, and the varnish of each thermosetting composition was dropped onto the fixed silicon wafer. Spin coating was performed at two rotation speed stages to form coating films with thicknesses of 3 to 5 μm, and evaluation samples A of Examples 2-1 to 2-3 and Comparative Example 2-1 were prepared. The first spin coating stage was performed at a rotation speed of 500 rpm for 5 seconds. The second spin coating stage was performed at a rotation speed of 1000 to 2000 rpm for 30 seconds to control the thickness. Subsequently, the solvent was removed from each of evaluation samples A of Examples 2-1 to 2-3 and Comparative Example 2-1 on a hot plate at a temperature of 80°C for 10 minutes to prepare evaluation samples B of Examples 2-1 to 2-3 and Comparative Example 2-1. The coating films of evaluation samples A and B were observed, and when the coating film covered the silicon wafer surface in both samples, the film-forming properties were evaluated as "A," and when the coating film did not cover the silicon wafer surface in one or both samples, the film-forming properties were evaluated as "B." The results are shown in Table 1.

[0155] (Dicing Resistance Test) A dicing resistance test was performed on resin films prepared using the varnishes of the thermosetting compositions of Examples 2-1 to 2-3, which had good results in the film-forming test. First, each evaluation sample B was heated in a dryer filled with nitrogen at a temperature of 100°C for 120 minutes to form a resin film on the silicon wafer surface. Next, dicing tape was attached to the surface of the silicon wafer opposite the resin film, and evaluation samples C of Examples 2-1 to 2-3 were prepared, each having dicing tape, a silicon wafer, and a resin film in this order. Next, a dicing resistance test was performed using each evaluation sample C using a dicing saw (Disco Corporation, product name: DFD6361) and a dicing blade (Disco Corporation, product names: Z1: ZH05-SD2000-N1-110FF, Z2: ZH05-SD4000-N1-70BB). The cutting method used was a half-cut method, with the incision made from the resin film side, with the incision depth set to 150 μm from the silicon wafer surface. The cooling water flow rate was 1.0 L / min. Under these conditions, dicing was performed to produce chips with a length of 5 mm and a width of 5 mm, producing evaluation samples D for Examples 2-1 to 2-3. Evaluation samples D were observed from the resin film side using an optical microscope (manufactured by Mitutoyo Corporation). When the resin film was not peeled off at the dicing intersection and no exposed silicon wafer was observed, the sample was rated "A" for excellent dicing resistance. When the resin film was peeled off at the dicing intersection or exposed silicon wafer was observed, the sample was rated "B." The results are shown in Table 1.

[0156] (Water-developability test) A water-developability test was carried out using Evaluation Sample D. Evaluation Sample D was irradiated with ultraviolet light from the resin film side using a conveyor-type UV exposure device (manufactured by GS Yuasa Corporation). The ultraviolet light irradiation was carried out at an illuminance of 120 mW / cm. ２ and an irradiation dose of 2000 mJ / cm ２The irradiation conditions were determined using an illuminance meter (UVR-T1, manufactured by Topcon Technohouse Corporation) and a 365 nm receiver (UD-T36). Subsequently, after irradiation with ultraviolet light, evaluation sample D was washed with water to remove resin components derived from the resin film using a spinner cleaning unit built into the dicing saw, and the silicon wafer was dried. The water washing was performed using a two-fluid nozzle at a rotation speed of 1000 rpm for 60 seconds. The drying was performed at a rotation speed of 2000 rpm for 5 seconds. This operation was repeated twice to obtain evaluation sample E. The dicing edge of evaluation sample E was observed using an optical microscope (manufactured by Mitutoyo Corporation), and when no residue was observed at the dicing edge, the sample was evaluated as having excellent water developability as "A," when residue was observed at the dicing edge within a range of less than 10 μm from the dicing edge, the sample was evaluated as "B," and when residue was observed at the dicing edge within a range of 10 μm or more from the dicing edge, the sample was evaluated as "C." The results are shown in Table 1.

[0157]

[0158] As shown in Table 1, the thermosetting compositions of the Examples were superior in film-forming properties compared to the thermosetting compositions of the Comparative Examples. It was also found that the thermosetting compositions of the Examples were superior in dicing resistance and water-developability. These results confirmed that the thermosetting compositions of the present disclosure can be melted by light irradiation, can form a cured product (photo-meltable composition) from which the resin component produced by melting by light irradiation can be removed with an aqueous solvent, and further have excellent film-forming properties.

[0159] 1...semiconductor wafer, 1a...semiconductor chip, 3...resin film, 3a...resin film piece, 5...dicing tape, 7...semiconductor chip with resin film piece, 9...dicing blade, 10...laminated body, 11...aqueous solvent, 13...support member, 15...adhesive layer, 20...semiconductor device

Claims

1. A thermosetting composition comprising: a polythiol compound having a disulfide bond and a hydroxyl group; a cyclic ether compound having a polyether group and two or more cyclic ether groups; a curing accelerator; and a photoradical generator.

2. The thermosetting composition according to claim 1, wherein the weight average molecular weight of the polythiol compound is 2,000 or more.

3. The thermosetting composition according to claim 1 or 2, wherein the cyclic ether group is a monovalent group containing an oxirane ring.

4. The thermosetting composition according to claim 1 or 2, wherein the polythiol compound has a structure represented by formula (XA). [In formula (XA), * represents a bond.] 5. A cured product of the thermosetting composition according to claim 1 or 2.

6. A photo-meltable composition comprising: a reaction product of a polythiol compound having a disulfide bond and a hydroxyl group, and a cyclic ether compound having a polyether group and two or more cyclic ether groups; and a photo-radical generator.

7. The photo-meltable composition according to claim 6, wherein the weight-average molecular weight of the polythiol compound is 2,000 or more.

8. The photo-meltable composition according to claim 6 or 7, wherein the cyclic ether group is a monovalent group containing an oxirane ring.

9. The photo-meltable composition according to claim 6 or 7, wherein the polythiol compound has a structure represented by formula (XA). [In formula (XA), * represents a bond.] 10. A method for manufacturing a structure, comprising: a step of irradiating light onto at least a portion of a first structure comprising a cured product of the thermosetting composition according to claim 5; and a step of developing the light-irradiated first structure with an aqueous solvent to obtain a second structure.

11. A method for manufacturing a structure, comprising: a step of irradiating light onto at least a portion of a first structure comprising the photo-meltable composition according to claim 6 or 7; and a step of developing the irradiated first structure with an aqueous solvent to obtain a second structure.

12. A method for manufacturing a semiconductor device, comprising: a resin film forming step of forming a resin film containing a cured product of the thermosetting composition described in claim 5 on a semiconductor wafer; a resin film piece-attached semiconductor chip fabrication step of dicing the semiconductor wafer on which the resin film has been formed with a dicing blade to fabricate individual semiconductor chips with resin film pieces; and a resin film piece removal step of irradiating light onto the resin film pieces of the resin film piece-attached semiconductor chips to remove the resin film pieces from the resin film piece-attached semiconductor chips.

13. The method for manufacturing a semiconductor device according to claim 12, wherein the resin film piece removing step is a step of removing the resin film piece from the semiconductor chip with the resin film piece by using a water-based solvent.

14. A method for manufacturing a semiconductor device, comprising: a resin film forming step of forming a resin film containing the photo-fusible composition according to claim 6 or 7 on a semiconductor wafer; a resin film piece-attached semiconductor chip fabrication step of dicing the semiconductor wafer on which the resin film has been formed with a dicing blade to fabricate individual semiconductor chips with resin film pieces; and a resin film piece removal step of irradiating light onto the resin film pieces of the resin film piece-attached semiconductor chips to remove the resin film pieces from the resin film piece-attached semiconductor chips.

15. The method for manufacturing a semiconductor device according to claim 14, wherein the resin film piece removing step is a step of removing the resin film piece from the semiconductor chip with the resin film piece by using a water-based solvent.

16. A polythiol compound that is a reaction product of a polythiol compound having a disulfide bond and a cyclic ether compound having a polyether group and two or more cyclic ether groups, the polythiol compound having a hydroxyl group in the molecule.

17. The polythiol compound according to claim 16, having a weight average molecular weight of 2,000 or more.

18. The polythiol compound according to claim 16 or 17, wherein the cyclic ether group is a monovalent group containing an oxirane ring.

19. The polythiol compound according to claim 16 or 17, having a structure represented by formula (XA): [In formula (XA), * represents a bond.]

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