Manufacturing method of housing, photocurable resin sheet, and photocurable resin sheet cured product

Abstract

To provide a manufacturing method of a housing that can fix a resin cured product to a housing with good accuracy and a photocurable resin sheet cured product that can be fixed to a housing with good accuracy.SOLUTION: A manufacturing method of a housing includes: a cured product preparation step of preparing a photocurable resin sheet cured product by irradiation a photocurable resin sheet with an active energy ray; and an adhesion step of adhering the photocurable resin sheet cured product prepared in the cured product preparation step to a housing by heating.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a housing, a photocurable resin sheet, and a cured product of the photocurable resin sheet. [Background technology]

[0002] Photocurable resin compositions have been widely used for optical applications such as displays, adhesives for optical semiconductors, lenses, protective films, etc. Most of these resin compositions are liquid at room temperature (25°C) and are used by the dispensing method.

[0003] Mobile 3D cameras and the like incorporate optical semiconductor packages in which optical elements such as microlenses are placed on top of an optical semiconductor element. Summary of the Invention [Problem to be solved by the invention]

[0004] In the manufacturing process of an optical semiconductor package housing having a shaped lens such as a microlens, a shape-imparting layer using a photo-radical curable resin has been used. Since this shape-imparting layer does not have adhesiveness to the package housing after photo-curing, a separate adhesive is applied to fix the shape-imparting layer to the housing. A conventional manufacturing method of an optical semiconductor package housing will be described with reference to FIG. 1.

[0005] After applying the liquid photoradical curable resin composition 100 to the substrate sheet 12, the mold 11 is pressed against the substrate sheet 12 to shape the liquid photoradical curable resin composition 100 into a shape that conforms to the shape of the mold. Next, the shaped liquid photoradical curable resin composition 100 is irradiated with ultraviolet light to prepare a photoradical curable resin cured product 101, which is then released from the mold 11. The photoradical curing reaction proceeds very quickly and the curing reaction is almost completely completed, so that the photoradical curable resin cured product 101 usually has almost no adhesive strength and cannot be directly fixed to the housing 13 (left side of FIG. 1). Therefore, the photoradical curable resin cured product 101 is fixed to the housing 13 using a liquid adhesive 102 (right side of FIG. 1).

[0006] As described above, when using conventional photo-radical curable resins, it is necessary to use a liquid adhesive when fixing the cured resin to the housing. As a result of investigations by the present inventors, it became clear that, as a result, the adhesive may overflow, and alignment problems such as misalignment or tilt of the cured resin may easily occur due to the thickness of the adhesive layer or the hardening of the adhesive layer, making it difficult to fix the cured resin to the housing with high accuracy. An object of the present invention is to provide a method for manufacturing a housing that can fix a cured resin material to the housing with high precision, and a cured photocurable resin sheet that can be fixed to the housing with high precision. [Means for solving the problem]

[0007] That is, the present invention (1) provides a cured product preparation step of irradiating a photocurable resin sheet with active energy rays to prepare a photocurable resin sheet cured product; and a bonding step of heating the cured photocurable resin sheet prepared in the cured product preparation step to bond it to a housing.

[0008] The present invention (2) relates to a method for manufacturing a housing according to the present invention (1), in which no adhesive is used in the bonding step.

[0009] The present invention (3) relates to the method for producing a housing according to the present invention (1) or (2), wherein the photocurable resin sheet is a photocationically curable resin sheet.

[0010] The present invention (4) relates to the method for producing a casing according to any one of the present inventions (1) to (3), wherein the photocurable resin sheet is a shaped sheet.

[0011] The present invention (5) is characterized in that in the cured product preparation step, the amount of ultraviolet radiation is 600 to 25,000 mJ / cm 2 The present invention relates to a method for producing the housing according to any one of the aspects (1) to (4).

[0012] The present invention (6) relates to the method for producing a casing according to any one of the present inventions (1) to (5), wherein the cured product of the photocurable resin sheet is an optical material.

[0013] The present invention (7) relates to a photocurable resin sheet used in the method for producing a housing according to any one of the present inventions (1) to (6).

[0014] The present invention (8) relates to a cured photocurable resin sheet having an adhesive strength of 13 MPa or more when left to stand in a 150°C environment for 30 minutes and then in a 25°C environment for 2 hours.

[0015] The present invention (9) relates to the photocurable resin sheet cured product according to the present invention (8), which has a heat generation amount of 100 mJ / mg or more when heated from 25°C to 225°C at a temperature increase rate of 10°C / min and calculated from the exothermic peak observed after 50°C.

[0016] The present invention (10) relates to the photocurable resin sheet cured product according to the present invention (8) or (9), which is prepared by irradiating a photocationically curable resin sheet with active energy rays.

[0017] The present invention (11) is characterized in that the amount of ultraviolet light irradiation is 600 to 25,000 mJ / cm 2 The present invention relates to a photocurable resin sheet cured product according to the present invention (10).

[0018] The present invention (12) relates to the photocurable resin sheet cured product according to any one of the present inventions (8) to (11), wherein the photocurable resin sheet cured product is a shaped sheet.

[0019] The present invention (13) relates to the photocurable resin sheet cured product according to any one of the present inventions (8) to (12), wherein the photocurable resin sheet cured product is an optical material. Effect of the Invention

[0020] The manufacturing method for a housing of the present invention includes a cured product preparation step of irradiating a photocurable resin sheet with active energy rays to prepare a cured photocurable resin sheet product, and an adhesion step of heating the cured photocurable resin sheet product prepared in the cured product preparation step to adhere it to the housing, so that the cured resin product can be fixed to the housing with high precision.

[0021] The photocurable resin sheet cured product of the present invention has an adhesive strength of 13 MPa or more, and therefore is a photocurable resin sheet cured product that can be fixed to a housing with high accuracy. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram showing a schematic diagram of an example of a conventional method for manufacturing a housing. [Diagram 2] FIG. 2 is a diagram showing an example of a method for manufacturing a housing of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] As described above, when using conventional photo-radical curable resins, it is necessary to use a liquid adhesive when fixing the cured resin to a housing. As a result, the adhesive tends to overflow, and alignment problems such as misalignment or inclination of the cured resin are likely to occur due to the thickness of the adhesive layer or the hardening of the adhesive layer, making it difficult to fix the cured resin to the housing with high accuracy. On the other hand, the manufacturing method of the housing of the present invention includes a cured product preparation step of irradiating a photocurable resin sheet with active energy rays to prepare a photocurable resin sheet cured product, and an adhesion step of heating the photocurable resin sheet cured product prepared in the cured product preparation step to adhere to the housing. For example, in the adhesion step, the photocurable resin sheet cured product is placed at a desired position on the housing, and then heated, so that the photocurable resin sheet cured product can be adhered to the housing, and the resin cured product can be fixed to the housing with high accuracy.

[0024] <Housing manufacturing method> The method for manufacturing a housing of the present invention is not particularly limited as long as it includes a cured product preparation step of irradiating a photocurable resin sheet with active energy rays to prepare a photocurable resin sheet cured product, and an adhesion step of heating the photocurable resin sheet cured product prepared in the cured product preparation step to adhere it to the housing.

[0025] <<Photocurable resin sheet>> First, the photocurable resin sheet will be described. The photocurable resin sheet contains (A) a polymeric compound and (B) a low molecular weight compound, and it is preferable that an epoxy group and a photopolymerization initiator group (preferably an epoxy group, an oxetanyl group, and a photopolymerization initiator group) are each independently present in the polymeric compound (A) or the low molecular weight compound (B). In this specification, the fact that the groups are each independently present in the compound means that each of the epoxy group, oxetanyl group, and photopolymerization initiator group is present in the polymer compound (A) or the low molecular weight compound (B) independently of other groups. For example, the epoxy group may be present in the polymer compound (A), the oxetanyl group may be present in the low molecular weight compound (B1), and the photopolymerization initiator group may be present in the low molecular weight compound (B2), or the epoxy group, oxetanyl group, and photopolymerization initiator group may be present in one polymer compound (A).

[0026] (A) Polymer compound The weight average molecular weight of the polymer compound (A) (preferably a poly(meth)acrylic resin) is not particularly limited, but is preferably 1,000 to 1,000,000, and more preferably 10,000 to 100,000. If it is less than 1,000, it becomes liquid at room temperature and cannot maintain a sheet shape, and if it exceeds 1,000,000, it does not dissolve in a solvent and may not be processed into a sheet shape. The polymer compound (A) may be used alone or in combination of two or more kinds. In this specification, the weight average molecular weight of a polymer compound is a value determined by dissolving the polymer compound in tetrahydrofuran, measuring the molecular weight using a GPC apparatus (HLC-8320GPC, manufactured by Tosoh Corporation) under the following conditions, and converting the molecular weight into polystyrene equivalent. Column: TSKgel Super HZMH / HZ4000 / HZ3000 / HZ2000 Column size: 6.0mm I.D. x 150mm Eluent:THF Flow rate: 0.6mL / min Detector: RI Column temperature: 40℃ Injection volume: 20μL

[0027] The glass transition temperature (Tg) of the polymer compound (A) is not particularly limited, but in order to obtain higher handleability and storage modulus G', it is preferably -20°C or higher, more preferably -10°C or higher, even more preferably 0°C or higher, particularly preferably 5°C or higher, and most preferably 10°C or higher. The upper limit is not particularly limited, but is preferably 100°C or lower, more preferably 80°C or lower, and even more preferably 60°C or lower. In this specification, the glass transition temperature (Tg) of a polymer compound means the temperature at which the loss tangent (tan δ) peaks as confirmed in a DMA method (tensile method) under the conditions of a heating rate of 5° C. / min, a sample width of 5 mm, a chuck distance of 20 mm, and a frequency of 10 Hz.

[0028] The polymer compound (A) is not particularly limited, and examples thereof include poly(meth)acrylic resin, phenoxy resin, polyurethane resin, silicone resin, polyester resin, polyamide resin, polyimide resin, epoxy resin, and other resins. Among these, poly(meth)acrylic resin is preferred from the viewpoint of photocurability and solubility in solvent. The polymer compound (A) may be used alone or in combination of two or more kinds.

[0029] Examples of poly(meth)acrylic resins include polymers obtained by polymerizing (meth)acrylic acid esters as monomers, such as (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters. In this specification, "(meth)acrylic" means "acrylic and / or methacrylic".

[0030] Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, and eicosyl (meth)acrylate. Examples of the (meth)acrylic acid cycloalkyl ester include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, etc. Examples of the (meth)acrylic acid aryl ester include phenyl (meth)acrylate, benzyl (meth)acrylate, etc. These (meth)acrylic acid esters may be used alone or in combination of two or more kinds.

[0031] The poly(meth)acrylic resin can also be copolymerized with other monomers that are copolymerizable with the above-mentioned (meth)acrylic acid esters. Examples of the other monomers include carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, acrylamide, acrylonitrile, etc. Examples of the carboxyl group-containing monomers include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, etc. Examples of the acid anhydride monomers include maleic anhydride, itaconic anhydride, etc. Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate. Examples of sulfonic acid group-containing monomers include styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, and (meth)acryloyloxynaphthalenesulfonic acid. Examples of phosphoric acid group-containing monomers include 2-hydroxyethyl acryloyl phosphate. These other monomers may be used alone or in combination of two or more.

[0032] The polymerization method for the poly(meth)acrylic resin is not particularly limited, and examples thereof include solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization.

[0033] The phenoxy resin may be a polyhydroxy polyether polymerized from a bisphenol and epichlorohydrin. The bisphenol may be bisphenol A or bisphenol F, with bisphenol A being preferred from the viewpoints of transparency and heat resistance.

[0034] The polyurethane resin is not particularly limited as long as it has a urethane bond as a repeating unit in the main chain, and examples thereof include polymers of aliphatic or aromatic diols and aromatic or aliphatic diisocyanates, etc. These may be used alone or in combination of two or more kinds.

[0035] The silicone resin is not particularly limited as long as it has a siloxane bond as a repeating unit in the main chain, and examples thereof include polymers of diphenylsilane and dimethylsilane, etc. These may be used alone or in combination of two or more kinds.

[0036] The polyester resin is not particularly limited as long as it has an ester bond as a repeating unit in the main chain, and examples thereof include polymers of aliphatic or aromatic diols and aliphatic or aromatic dicarboxylic acids, etc. These may be used alone or in combination of two or more kinds.

[0037] The polyamide resin is not particularly limited as long as it has an amide bond as a repeating unit in the main chain, and examples thereof include polymers of aliphatic or aromatic diamines and aliphatic or aromatic dicarboxylic acids, ring-opening polymers of cyclic lactams, etc. These may be used alone or in combination of two or more kinds.

[0038] The polyimide resin is not particularly limited as long as it has imide bonds as repeating units in the main chain, and examples thereof include polymers of aliphatic or aromatic diamines and aliphatic or aromatic acid anhydrides, etc. These may be used alone or in combination of two or more.

[0039] Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins such as triglycidyl isocyanurate and hydantoin epoxy, water-added bisphenol A type epoxy resins, aliphatic epoxy resins, glycidyl ether type epoxy resins, and cresol novolac type epoxy resins.

[0040] The polymer compound (A) may have all of the epoxy group and the photopolymerization initiator group (preferably an epoxy group, an oxetanyl group, and a photopolymerization initiator group), may have only some of the substituents, or may not have any of the substituents. Both the polymer compound (A) and the low molecular weight compound (B) may have these substituents, but the low molecular weight compound (B) must have the substituents that the polymer compound (A) does not have. When the polymer compound (A) has multiple substituents, it is not necessary for one type of polymer compound (A) to have multiple substituents, and multiple polymer compounds (A) having one substituent can be used in combination. Among these substituents, the polymer compound (A) preferably has an epoxy group, more preferably has an aliphatic epoxy group, and even more preferably has a glycidyl (meth)acrylate group.

[0041] When the polymer compound (A) is a polymer compound that polymerizes by radical polymerization, such as a poly(meth)acrylic resin, the method for introducing an epoxy group, an oxetanyl group, or a photopolymerization initiator group is not particularly limited, and examples thereof include a method of copolymerizing a monomer having an epoxy group, an oxetanyl group, or a photopolymerization initiator group with the various monomers described above.

[0042] Examples of the monomer having an epoxy group include a monomer having an aliphatic epoxy group, a monomer having an alicyclic epoxy group, and a monomer having an aromatic epoxy group. Among these, a monomer having an aliphatic epoxy group is preferred.

[0043] Examples of monomers having an aliphatic epoxy group include glycidyl ethers of polyhydric alcohols such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, tetraglycidyl ether of sorbitol, hexaglycidyl ether of dipentaerythritol, diglycidyl ether of polyethylene glycol, and diglycidyl ether of polypropylene glycol; polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as propylene glycol, trimethylolpropane, and glycerin; diglycidyl esters of aliphatic long-chain dibasic acids; monoglycidyl ethers of aliphatic higher alcohols; glycidyl esters of higher fatty acids; and (meth)acrylates of aliphatic epoxy compounds such as epoxidized soybean oil, epoxy octyl stearate, epoxy butyl stearate, epoxidized soybean oil, and epoxidized polybutadiene. Specific examples include epoxy group-containing (meth)acrylates such as 4-hydroxybutyl (meth)acrylate glycidyl ether and glycidyl (meth)acrylate.

[0044] Examples of monomers having an alicyclic epoxy group include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexane carboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexane carboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexane carboxylate, bis(3,4-epoxycyclohexyl)methyl-3,4-epoxy-5-methylcyclohexane carboxylate, and bis(3,4-epoxycyclohexyl)methyl-3,4-epoxy-5-methylcyclohexane carboxylate. cycloaliphatic epoxy compounds such as 1,2-dimethylphenyl)adipate, 3,4-epoxy-6-methylcyclohexyl carboxylate, methylene bis(3,4-epoxycyclohexane), propane-2,2-diyl-bis(3,4-epoxycyclohexane), 2,2-bis(3,4-epoxycyclohexyl)propane dicyclopentadiene diepoxide, ethylene bis(3,4-epoxycyclohexane carboxylate), 1-epoxyethyl-3,4-epoxycyclohexane, 1,2-epoxy-2-epoxyethylcyclohexane, caprolactone-modified products, trimethylcaprolactone-modified products, and valerolactone-modified products thereof can be mentioned.

[0045] Examples of monomers having an aromatic epoxy group include (meth)acrylates of aromatic epoxy compounds such as monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to phenol, cresol, or butylphenol.

[0046] Examples of monomers having an oxetanyl group include oxetanyl group-containing (meth)acrylates such as 3-oxetanylmethyl (meth)acrylate, 3-methyl-oxetanylmethyl (meth)acrylate, 3-ethyl-oxetanylmethyl (meth)acrylate, 3-butyl-oxetanylmethyl (meth)acrylate, and 3-hexyl-oxetanylmethyl (meth)acrylate. Examples of monomers having a photopolymerization initiator group include triarylsulfonium salts having an acryloyl group.

[0047] When the polymer compound (A) is a phenoxy resin, a polyurethane resin, a silicone resin, a polyester resin, a polyamide resin, a polyimide resin, or an epoxy resin, the method of introducing the epoxy group, the oxetanyl group, or the photopolymerization initiator group is not particularly limited. For the epoxy group, for example, a method of reacting a hydroxyl group-containing resin with a chloro group-containing epoxy compound such as epichlorohydrin can be mentioned. For the oxetanyl group, for example, a method of reacting a hydroxyl group-containing resin with a chloro group-containing oxetane compound such as 3-chlorooxetane can be mentioned. For the photopolymerization initiator group, for example, a method of crosslinking a hydroxyl group-containing resin with a hydroxyl group-containing photopolymerization initiator with polyisocyanate or diisocyanate can be mentioned.

[0048] When the polymer compound (A) has an epoxy group, the epoxy equivalent of the polymer compound (A) is not particularly limited, but is preferably 100 to 10,000 g / eq, more preferably 100 to 1,000 g / eq. If the epoxy equivalent is less than 100 g / eq, the density of the epoxy group is too high, and the reaction may not proceed completely due to steric hindrance between side chains, while if it exceeds 10,000 g / eq, the density of the epoxy group is too low, and the reaction may not proceed. In this specification, the epoxy equivalent of the polymer compound (A) is measured in accordance with JIS K7236 (2001).

[0049] When the polymer compound (A) has an oxetanyl group, the oxetanyl equivalent of the polymer compound (A) is not particularly limited, but is preferably 100 to 10,000 g / eq, more preferably 100 to 1,000 g / eq. If the oxetanyl equivalent is less than 100 g / eq, the density of the oxetanyl group is too high, and the reaction may not proceed completely due to steric hindrance between side chains, while if it exceeds 10,000 g / eq, the density of the oxetanyl group is too low, and the reaction may not proceed.

[0050] When the polymer compound (A) has a photopolymerization initiating group, the content of the photopolymerizable initiating group in the polymer compound (A) is preferably 0.1 to 50 mol % or more. If the content is less than 0.1 mol %, the photocurability may be impaired, and if it exceeds 50 mol %, the molecular weight may not increase due to an excess of the initiator group, and the photocurability may be impaired.

[0051] The content of the polymer compound (A) in the photocurable resin sheet is not particularly limited, but is preferably 85% by mass or more, more preferably 88% by mass or more, even more preferably 92% by mass or more, particularly preferably 95% by mass or more, and is preferably 99% by mass or less, more preferably 98% by mass or less. If the content is less than 85% by mass, the sheet shape may not be maintained at room temperature. If the content is 95% by mass or more, a better storage modulus G' tends to be obtained.

[0052] (B) Low molecular weight compound The upper limit of the molecular weight of the low molecular weight compound (B) is not particularly limited, but is preferably less than 1,000, more preferably 800 or less, and even more preferably 700 or less. If the molecular weight is 1,000 or more, the diffusion speed in the system becomes slow, and photocurability may be impaired. The lower limit is also not particularly limited, but is preferably 100 or more, and more preferably 400 or more. The low molecular weight compound (B) may be used alone or in combination of two or more kinds. In this specification, the molecular weight of a low molecular weight compound is a value calculated from the molecular structure of the compound, which is determined by NMR.

[0053] The low molecular weight compound (B) may have all of the epoxy group and the photopolymerization initiator group (preferably the epoxy group, the oxetanyl group, and the photopolymerization initiator group), may have only some of the substituents, or may not have any of the substituents. Both the polymer compound (A) and the low molecular weight compound (B) may have these substituents, but the polymer compound (A) must have the substituents that the low molecular weight compound (B) does not have. When the low molecular weight compound (B) has multiple substituents, it is not necessary for one type of low molecular weight compound (B) to have multiple substituents, and multiple low molecular weight compounds (B) having one substituent can be used in combination. Among these substituents, the low molecular weight compound (B) preferably has an oxetanyl group or a photopolymerization initiator group.

[0054] Examples of the low molecular weight compound (B) having an epoxy group include aliphatic epoxy compounds, alicyclic epoxy compounds, aromatic epoxy compounds, etc. Among these, alicyclic epoxy compounds are preferred.

[0055] Examples of the aliphatic epoxy compound include glycidyl ethers of polyhydric alcohols such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, tetraglycidyl ether of sorbitol, hexaglycidyl ether of dipentaerythritol, diglycidyl ether of polyethylene glycol, diglycidyl ether of polypropylene glycol, polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as propylene glycol, trimethylolpropane, and glycerin, diglycidyl esters of aliphatic long-chain dibasic acids, monoglycidyl ethers of aliphatic higher alcohols, glycidyl esters of higher fatty acids, epoxidized soybean oil, epoxy octyl stearate, epoxy butyl stearate, epoxidized soybean oil, and epoxidized polybutadiene. These may be used alone or in combination of two or more.

[0056] Examples of the alicyclic epoxy compounds include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexane carboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexane carboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclo Examples of the epoxy groups include hexane carboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexyl carboxylate, methylene bis(3,4-epoxycyclohexane), propane-2,2-diyl-bis(3,4-epoxycyclohexane), 2,2-bis(3,4-epoxycyclohexyl)propane dicyclopentadiene diepoxide, ethylene bis(3,4-epoxycyclohexane carboxylate), 1-epoxyethyl-3,4-epoxycyclohexane, 1,2-epoxy-2-epoxyethylcyclohexane, etc. In addition, caprolactone modified products, trimethylcaprolactone modified products, valerolactone modified products, etc. of these can also be used. These may be used alone or in combination of two or more.

[0057] Examples of aromatic epoxy compounds include monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to phenol, cresol, or butylphenol. These may be used alone or in combination of two or more.

[0058] Examples of the low molecular weight compound (B) having an oxetanyl group include 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene, 3-ethyl-3-(phenoxymethyl)oxetane, di[(3-ethyl-3-oxetanyl)methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, xyloxymethyl)oxetane, phenol novolak oxetane, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3-ethyl-3-oxetanylmethyl) ether, 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, ethyl diethylene glycol (3-ethyl-3-oxetanylmethyl) ether, di[1-ethyl(3-oxetanyl)]methyl ether, 3,7-bis(3-oxetanyl)-5-oxetane xanonane, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,3-bis[(3-ethyl-3-oxetanylmethoxy)methyl]propane, ethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, tricyclodecanediyldimethylene(3-ethyl-3-oxetanylmethyl)ether, trimethylolpropane tris(3-ethyl-3-oxetanylmethyl)ether, 1,4-bis(3-ethyl-3-oxetanylmethoxy)butane, 1,6-bis(3-ethyl-3-oxetanylmethoxy) )hexane, pentaerythritol tris(3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis(3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexakis(3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis(3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetrakis(3-ethyl-3-oxetanylmethyl) ether, and the like.These may be used alone or in combination of two or more. Among these, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane is preferred.

[0059] The low molecular weight compound (B) having a photopolymerization initiating group is not particularly limited as long as it has a group having the property of generating an ion pair or a radical upon light absorption, and examples thereof include a photocationic polymerization initiator having a photocationic polymerization initiating group and a photoradical polymerization initiator having a photoradical generating group.

[0060] The photocationic polymerization initiator generates cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet light, X-rays, and electron beams, and initiates the polymerization reaction of epoxy groups and oxetanyl groups. As the photocationic polymerization initiator, a photoacid generator, a photobase generator, etc. are preferred, and a photoacid generator is more preferred. When visible light is used as the active energy ray, it is preferable to use a photocationic polymerization initiator that is highly sensitive to light of 380 nm or more. Since the photocationic polymerization initiator is generally a compound that exhibits maximum absorption in the vicinity of 300 nm or a shorter wavelength range, by blending a photosensitizer that exhibits maximum absorption in a longer wavelength range, specifically, light of a wavelength longer than 380 nm, it is possible to respond to light of this wavelength range and promote the generation of cationic species or acid from the photocationic polymerization initiator.

[0061] The photoacid generator may be an onium salt consisting of an anion component and a cation component. Examples of the onium cation component include aromatic diazonium, aromatic sulfonium, aromatic iodonium, aromatic selenium, aromatic pyridinium, aromatic ferrocenium, and aromatic phosphonium. Among these, aromatic sulfonium is preferred.

[0062] The anion component is, for example, PF6 - , PF4(CF2CF3)2 - , SbF6 - , AsF6 - , SbCl6 - , BiCl5 - , SnCl6- , ClO4 - , dithiocarbamate anion, SCN - , trifluoromethanesulfonate, etc. Among these, PF6 - , SbF6 - and AsF6 - is preferred, PF6 - and SbF6 - is more preferred.

[0063] As described above, the photoradical curing reaction proceeds very quickly, so the photoradical curable resin cured product usually has almost no adhesive strength and cannot be fixed directly to a housing. That is, the photoradical curable resin cured product has a very fast curing reaction, so the curing reaction proceeds completely and there is no room for the curing reaction to proceed further (almost completely cured state). Therefore, even if heat is applied to the cured product, there is no room for the curing reaction to proceed, so the adhesive strength is not exerted. On the other hand, the photocationic curing reaction has a slow reaction rate, so the curing reaction is easy to control, and it is possible to end the curing reaction in a state where there is room for the curing reaction to proceed in the obtained cured product. The cured product in a state where there is room for the curing reaction to proceed can be adhered to a housing or the like by applying heat. Therefore, it is preferable that the low molecular weight compound (B) is a photocationic polymerization initiator having a photocationic polymerization initiator group (low molecular weight compound (B) having a photocationic polymerization initiator group). Furthermore, it is more preferable to use a low molecular weight compound (B) having an oxetanyl group and a low molecular weight compound (B) having a photocationic polymerization initiator group in combination. In particular, it is preferable to use a combination of a polymer compound (A) having an epoxy group, a low molecular weight compound (B) having an oxetanyl group, and a low molecular weight compound (B) having a photocationic polymerization initiator group, and it is more preferable to use a combination of a polymer compound (A) which is a poly(meth)acrylic resin having an epoxy group, a low molecular weight compound (B) having an oxetanyl group, and a low molecular weight compound (B) having a photocationic polymerization initiator group. The low molecular weight compound (B) having a photocationic polymerization initiator group is preferably a photoacid generator, and more preferably an aromatic sulfonium.

[0064] The content of the low molecular weight compound (B) in the photocurable resin sheet is not particularly limited, but is preferably 0.5 to 15% by mass, more preferably 1 to 12% by mass. The lower limit is more preferably 2% by mass or more, and the upper limit is more preferably 8% by mass or less, particularly preferably 5% by mass or less. If the content is less than 0.5% by mass, the photocurability may be impaired, and if it exceeds 15% by mass, the compound may bleed onto the sheet surface, impairing the handleability. If the content is 5% by mass or less, a better storage modulus G' tends to be obtained.

[0065] When the low molecular weight compound (B) having an oxetanyl group and the low molecular weight compound (B) having a photocationic polymerization initiator group are used in combination, the content of the low molecular weight compound (B) having an oxetanyl group in the photocurable resin sheet is preferably 0.5 to 10 mass%, more preferably 0.5 mass% or more and less than 5 mass%. The upper limit is more preferably 4 mass% or less. If the content is less than 0.5 mass%, the photocurability may be impaired, and if it exceeds 10 mass%, it may bleed onto the sheet surface and impair the handleability. When the low molecular weight compound (B) having an oxetanyl group and the low molecular weight compound (B) having a photocationic polymerization initiator group are used in combination, the content of the low molecular weight compound (B) having a photocationic polymerization initiator group in the photocurable resin sheet is preferably 0.01 to 5 mass%, more preferably 0.05 to 2.5 mass%. If the content is less than 0.01% by mass, the photocuring properties may be impaired, whereas if it exceeds 5% by mass, the resin may bleed onto the sheet surface, impairing the handling properties and reducing the transparency.

[0066] The total content of the polymer compound (A) and the low molecular weight compound (B) in the photocurable resin sheet is preferably 90 mass% or more, more preferably 95 mass% or more, even more preferably 98 mass% or more, particularly preferably 99 mass% or more, and may be 100 mass%.

[0067] The photocurable resin sheet may contain other components in addition to the polymer compound (A) and the low molecular compound (B) as long as the effects of the present invention are not impaired. Examples of other components include photosensitizers and colorants. These may be used alone or in combination of two or more.

[0068] Examples of photosensitizers include anthracene compounds, pyrene compounds, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, photoreducible dyes, etc. These may be used alone or in combination of two or more. Anthracene compounds, which have excellent photosensitizing effects, are particularly preferred. The content of the photosensitizer is preferably 0.1 to 5% by mass, more preferably 0.5 to 3% by mass.

[0069] The storage modulus G' of the photocurable resin sheet is preferably 50,000 Pa or more at 25°C, more preferably 100,000 Pa or more, even more preferably 200,000 Pa or more, particularly preferably 300,000 Pa or more, most preferably 400,000 Pa or more, and most preferably 420,000 Pa or more. There is no particular upper limit, but it is preferably 1,000,000 Pa or less. If the storage modulus G' is less than 50,000 Pa, the photocurable resin sheet may become sticky (tacky) and the handling properties may become poor. The storage modulus can be measured using a dynamic viscoelasticity measuring device. Increasing the content of the polymer compound (A) in the photocurable resin sheet tends to result in a higher storage modulus G'. Furthermore, using a polymer compound (A) with a high glass transition temperature tends to result in a higher storage modulus G'. Also, removing more of the remaining solvent, such as methyl ethyl ketone, contained in the sheet tends to result in a higher storage modulus G'.

[0070] The light transmittance of the cured product (thickness 100 μm) of the photocurable resin sheet at a wavelength of 400 nm at 25° C. is preferably 70% or more, more preferably 80% or more. There is no particular upper limit, but it is preferably 99% or less. If the light transmittance is less than 70%, the transparency may be insufficient and the sheet may not be usable for optical purposes. The light transmittance can be measured using a spectrophotometer. By suppressing the light absorption in the ultraviolet region of the raw materials used, the light transmittance at a wavelength of 400 nm can be adjusted to fall within the above numerical range.

[0071] The preferred range of the refractive index of the cured product (thickness 100 μm) of the photocurable resin sheet with respect to light having a wavelength of 589 nm at 25° C. varies depending on the application of the photocurable resin sheet. For example, when the photocurable resin sheet is used for a lens, the refractive index is preferably 1.40 or more, more preferably 1.47 or more. There is no particular upper limit, but it is preferably 1.80 or less. The refractive index can be measured using a refractometer. By adjusting the refractive index of the raw materials used and their blending ratio, the refractive index for light with a wavelength of 589 nm can be adjusted to fall within the above numerical range.

[0072] A specific method for adjusting the light transmittance and the refractive index to be within the above numerical ranges may involve, for example, using a material that has low light absorption in the ultraviolet region, and adjusting the amount of a material that has light absorption (for example, a compound containing a photopolymerization initiator group) to a small amount, as necessary.

[0073] The photocurable resin sheet can be produced by casting a photocurable resin composition containing the above-mentioned polymer compound (A) and low molecular compound (B) and a solvent on a substrate, and drying the solvent as necessary. The photocurable resin composition containing the above-mentioned polymer compound (A) and low molecular compound (B) can also be processed into a film shape with a roll or extruded into a film shape from a T-die. If a substrate is used after that, the substrate may or may not be peeled off. In addition, a photocurable resin sheet produced on a substrate can be further stacked with another substrate to form a photocurable resin sheet sandwiched between the substrates. In this case, the photocurable resin sheet can be wound around a core to form a roll. In addition, sheets cut to a predetermined size can be stacked to form a single-leaf sheet.

[0074] The solvent is not particularly limited, but examples thereof include esters such as ethyl lactate, methyl acetate, and butyl acetate, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, polar solvents such as dimethylformamide and dimethyl sulfoxide, halogen-based solvents such as 1,1,1-trichloroethane and chloroform, ethers such as tetrahydrofuran and dioxane, aromatics such as benzene, toluene, and xylene, and fluorinated inert liquids such as perfluorooctane and perfluorotri-N-butylamine. These may be used alone or in combination of two or more. Among these, methyl ethyl ketone is preferred from the viewpoint of compatibility with the solute.

[0075] When the photocurable resin composition contains a solvent, the content of the solvent is not particularly limited, but is preferably 20 to 50 parts by mass per 100 parts by mass of the total mass of the above-mentioned polymer compound (A) and low molecular weight compound (B).

[0076] The substrate is, for example, a plastic substrate, and a plastic film can be suitably used. The material of the plastic substrate is not particularly limited, but examples thereof include polyolefin, polyester, polyurethane, polycarbonate, polyether ether ketone, polyimide, polyetherimide, polyamide, wholly aromatic polyamide, polyvinyl chloride, polyvinylidene chloride, polyphenyl sulfide, aramid, fluororesin, cellulose-based resin, silicone resin, etc. Examples of polyolefin include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, very low-density polyethylene, random copolymerized polypropylene, block copolymerized polypropylene, homopolypropylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, etc. Examples of polyester include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc. These materials may be used alone or in combination of two or more. The substrate may have a single layer structure or a multi-layer structure. Furthermore, the substrate preferably has light transmittance.

[0077] The photocurable resin sheet can be cured by light irradiation such as irradiation with active energy rays such as ultraviolet rays (for example, wavelengths of about 365 nm), visible light rays, X-rays, and electron beams. As a light source for light irradiation, an LED, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, and the like can be used. As an active energy ray, there is no particular limitation, but ultraviolet rays are usually used.

[0078] As described above, the photocationic curing reaction has a slow reaction rate, so the curing reaction is easy to control, and the curing reaction can be terminated while leaving room for the curing reaction to proceed in the obtained cured product. The cured product while leaving room for the curing reaction to proceed can be bonded to a housing or the like by applying heat, so in the present invention, the photocurable resin sheet is preferably a photocationic curable resin sheet containing a low molecular weight compound (B) having a photocationic polymerization initiation group. In this way, when a photocationic curable resin sheet is used, it is possible to bond the sheet to a housing or the like by post-treatment heating (post-cure) even after photocuring.

[0079] The amount of irradiation of the photocurable resin sheet with active energy rays such as ultraviolet rays (preferably ultraviolet rays, more preferably ultraviolet rays with a wavelength of 365 nm, and even more preferably ultraviolet rays with a wavelength of 365 nm when a xenon lamp is used) is preferably 600 to 25,000 mJ / cm 2 , more preferably 1,000 to 20,000 mJ / cm 2 , and more preferably 1,500 to 15,000 mJ / cm 2 , particularly preferably 2,000 to 10,000 mJ / cm 2 , and most preferably 2,500 to 9,000 mJ / cm 2 When the irradiation dose is within the above range, it is possible to terminate the curing reaction in the obtained cured product while leaving room for the curing reaction to proceed, and there is a tendency that adhesion to a housing or the like becomes possible by applying heat. 2 If the irradiation dose is less than 600 mJ / cm, the curing reaction does not proceed too much, and therefore it is possible to prevent the curing reaction from proceeding too much, resulting in a cured product having insufficient room for the curing reaction to proceed. 2 If the curing reaction is initiated sufficiently, it tends to be possible to suppress a situation in which the curing reaction itself does not initiate sufficiently, resulting in failure to achieve adhesion even when heat is applied.

[0080] The thickness of the photocurable resin sheet (excluding the substrate) is preferably 10 to 1,000 μm, and more preferably 30 to 500 μm. If the thickness of the photocurable resin sheet is less than 10 μm, the handling properties may be impaired, and if it exceeds 1,000 μm, the photocurability may be impaired.

[0081] The photocurable resin sheet is preferably used for optical applications. The photocurable resin sheet is preferably used for imprinting applications. The photocurable resin sheet is preferably used in the method for manufacturing a housing of the present invention.

[0082] <<Photocurable resin sheet cured product>> Next, the photocurable resin sheet cured product will be described. The photocurable resin sheet cured product is obtained by curing the photocurable resin sheet, and is prepared, for example, by irradiating the photocationic curable resin sheet with active energy rays (preferably ultraviolet rays with the above-mentioned irradiation amount).

[0083] The photocurable resin sheet cured product has an adhesive strength of 13 MPa or more, preferably 15 MPa or more, more preferably 17 MPa or more, even more preferably 20 MPa or more, and particularly preferably 23 MPa or more when left to stand in a 150° C. environment for 30 minutes and then in a 25° C. environment for 2 hours, and the upper limit is not particularly limited, but is preferably 50 MPa or less, more preferably 35 MPa or less. This tends to make it possible to more suitably adhere the photocurable resin sheet cured product to a housing or the like by applying heat to the photocurable resin sheet cured product. The adhesive strength is measured by the method described in <Adhesive strength of cured photocurable resin sheet after post-cure> in the Examples.

[0084] The photocurable resin sheet cured product is heated from 25°C to 225°C at a heating rate of 10°C / min, and the calorific value calculated from the exothermic peak observed after 50°C is preferably 100mJ / mg or more, more preferably 110mJ / mg or more, even more preferably 120mJ / mg or more, particularly preferably 130mJ / mg or more, and most preferably 140mJ / mg or more. The larger the calorific value, the more room there is for the curing reaction, so the upper limit is not particularly limited, but is preferably 300mJ / mg or less. Thereby, by applying heat to the photocurable resin sheet cured product, it tends to be more suitable for adhesion to a housing or the like. The calorific value indicates the calorific value response accompanying the thermal response (curing reaction) when the cured photocurable resin sheet is heated, and is measured by the method described in <DSC calorific value of cured photocurable resin sheet> in the Examples.

[0085] A photocurable resin sheet cured product that satisfies the preferred numerical ranges for the adhesive strength and heat generation amount can be prepared by, for example, irradiating the photocationic curable resin sheet with active energy rays (preferably ultraviolet rays in the above-mentioned irradiation amount) by terminating the curing reaction while leaving room for the curing reaction to proceed in the obtained cured product when curing the photocurable resin sheet.

[0086] The photocurable resin sheet cured product is preferably a shaped sheet. The shape of the shaped sheet is not particularly limited, but examples thereof include a rectangular, circular, triangular, polygonal, stepped shape, etc., as viewed in the same direction as the thickness direction of the sheet.

[0087] The photocurable resin sheet cured product is preferably an optical material. The optical material is not particularly limited, but examples thereof include adhesives for displays and optical semiconductors, lenses, protective films, and optical electronic components such as diffractive optical elements (DOEs). Examples of lenses include microlens arrays (MLAs).

[0088] <<An example of a housing manufacturing method>> The manufacturing method of the housing of the present invention is not particularly limited as long as it includes a cured product preparation step of irradiating a photocurable resin sheet with active energy rays to prepare a photocurable resin sheet cured product, and an adhesion step of heating the photocurable resin sheet cured product prepared by the cured product preparation step to adhere to the housing. An example of the manufacturing method of the housing of the present invention will be described below with reference to the drawings. Note that the manufacturing method of the housing of the present invention may include steps other than the following steps, or may not include some of the following steps.

[0089] <<<Primary adhesion process>>> FIG. 2 is a diagram showing an example of a method for manufacturing a housing of the present invention. In the primary bonding step, the photocurable resin sheet 200 is attached to the base sheet 12 and heated. This allows the photocurable resin sheet 200 to be bonded to the base sheet 12.

[0090] The photocurable resin sheet described in <<Photocurable resin sheet>> may be used as the photocurable resin sheet 200. Moreover, the base material sheet 12 may be a sheet of the base material described in <<Photocurable resin sheet>>.

[0091] The heating temperature is preferably 50 to 150° C., more preferably 80 to 120° C., and the heating time is preferably 1 second to 30 minutes, more preferably 10 seconds to 10 minutes.

[0092] In the present invention, since the photocurable resin sheet and the base sheet are both in sheet form, they can be easily bonded together, and the housing can be produced with good productivity.

[0093] <<<Attachment process to mold>>> In the die attachment step, the photocurable resin sheet 200 (in FIG. 2, a laminated sheet of the photocurable resin sheet 200 and the base sheet 12 obtained in the primary adhesion step) is attached to the die 11 and heated. As a result, the photocurable resin sheet 200 is shaped (imprinted) into a shape that matches the shape of the die.

[0094] The mold 11 may be of any shape and made of any material.

[0095] The heating temperature may be any temperature that softens the resin sheet to conform to the shape of the mold, and is preferably 50 to 150°C, more preferably 80 to 120°C. The heating time is preferably 1 second to 10 minutes, more preferably 10 seconds to 10 minutes.

[0096] In the present invention, since the photocurable resin sheet is in a sheet form, it can be easily attached to a mold, and the housing can be produced with good productivity.

[0097] <<<Cured product preparation process>>> In the cured product preparation step, the photocurable resin sheet is irradiated with active energy rays to prepare a cured photocurable resin sheet. In Fig. 2, the shaped photocurable resin sheet 200 obtained in the attachment step to the mold is irradiated with ultraviolet rays, and the curing reaction of the photocurable resin sheet 200 progresses to prepare a cured photocurable resin sheet 201.

[0098] The photocurable resin sheet cured product described in <<Photocurable resin sheet cured product>> may be used as the photocurable resin sheet cured product 201. The type and amount of active energy rays may be the same as those described in <<Photocurable resin sheet>>.

[0099] After the curing reaction is completed, the photocurable resin sheet cured product 201 is released from the mold 11. As shown in Fig. 2, the photocurable resin sheet cured product released from the mold is a shaped photocurable resin sheet cured product.

[0100] <<<Adhesion process (secondary adhesion process)>>> In the secondary adhesion step, the photocurable resin sheet cured product prepared in the cured product preparation step is heated to adhere to the housing. In Fig. 2, the shaped photocurable resin sheet cured product 201 obtained in the cured product preparation step is heat-treated in a state of contact (preferably in close contact) with the housing 13, so that the shaped photocurable resin sheet cured product 201 can be adhered to the housing 13. This is because, as described above, the photocurable resin sheet cured product in a state in which there is still room for the curing reaction to proceed can be adhered to the housing by applying heat (has a secondary adhesion function).

[0101] The housing 13 is not particularly limited, and examples thereof include an optical semiconductor package housing, a housing for sensor use, and a housing created by imprinting. Among these, an optical semiconductor package housing is preferable. An example of an optical semiconductor package housing is a housing having a semiconductor element inside the housing. The material of the housing is also not particularly limited, and examples thereof include the same material as the base material.

[0102] The heating temperature is preferably 50 to 175° C., more preferably 80 to 150° C., and the heating time is preferably 15 to 180 minutes, more preferably 30 to 90 minutes. When heating the cured photocurable resin sheet, it is preferable to appropriately adjust the temperature and time and allow the reaction to proceed until the cured photocurable resin sheet is completely cured.

[0103] In the present invention, it is preferable not to use an adhesive in the secondary bonding step. By not using an adhesive, a housing can be manufactured in which the cured resin is fixed with high accuracy. In addition, the omission of the adhesive application step improves productivity.

[0104] Through the above steps, a housing in which the cured resin is fixed with high precision can be manufactured. EXAMPLES

[0105] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following, "parts" and "%" mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0106] The materials used in the examples and comparative examples are shown below.

[0107] ·High molecular compound (A) Epoxy group-containing (meth)acrylic resin 1 (1HM2067 manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 60,000, epoxy equivalent 433 g / eq, glass transition temperature 15°C, (meth)acrylic resin having an aliphatic epoxy group (glycidyl (meth)acrylate group)) Epoxy group-containing (meth)acrylic resin 2 (1HM2095 manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 60,000, epoxy equivalent 306 g / eq, (meth)acrylic resin having an aliphatic epoxy group (glycidyl (meth)acrylate group)) Epoxy group-containing (meth)acrylic resin 3 (1HM2164 manufactured by Taisei Fine Chemical Co., Ltd., weight average molecular weight 60,000, epoxy equivalent 284 g / eq, (meth)acrylic resin having an aliphatic epoxy group (glycidyl (meth)acrylate group)) Phenoxy resin 1 (1256B40 manufactured by Mitsubishi Chemical Corporation, epoxy functional group equivalent 7800g / eq) Epoxy resin 1 (Daicel EHPE3150 (alicyclic epoxy resin (epoxy equivalent 185g / eq))) Epoxy resin 2 (Daicel Celloxide 2021P (alicyclic epoxy resin (epoxy equivalent: 134 g / eq)))

[0108] ·Low molecular compound (B) Oxetanyl group-containing compound (3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, OXT221 manufactured by Toagosei Co., Ltd., molecular weight 214) Photocationic polymerization initiator 1 (triarylsulfonium salt, CPI101A manufactured by San-Apro Co., Ltd., molecular weight 558, anion: SbF6 - ) Photocationic polymerization initiator 2 (ADEKA Optomer SP-170, molecular weight 633, manufactured by ADEKA Corporation) Photoradical polymerization initiator 1 (Irgacure 651, molecular weight 256, manufactured by DJK Co., Ltd.)

[0109] Examples and Comparative Examples A photocurable resin composition was obtained by dissolving each component in methyl ethyl ketone in the ratio (solid content ratio) shown in Table 1. A PET film was used as a substrate, and the photocurable resin composition was cast onto the substrate and dried to obtain a photocurable resin sheet with a thickness of about 100 μm. The obtained photocurable resin sheet was photocured by irradiating it with ultraviolet light in the amount shown in Table 1, to obtain a cured photocurable resin sheet. The obtained cured photocurable resin sheet was evaluated by the following methods. The evaluation results are shown in Table 1.

[0110] <Adhesive strength of cured photocurable resin sheet> The photocurable resin sheet was attached to a glass plate (20 x 20 x 1 mm) at 0.5 MPa while being heated at 80°C. A xenon lamp is used to apply a prescribed cumulative light dose (mJ / cm2) to a laminate of a photocurable resin sheet (resin layer 30 μm) and glass. 2 ) was irradiated with light. The laminate of the photocurable resin sheet and glass after light irradiation was heated at 120° C. while a silicon wafer chip (2×2×0.5 mm) was pressed vertically against the surface of the photocurable resin sheet with a load of 1.78 kg for 5 seconds. After leaving it to stand for 2 hours in an environment of 25°C, the terminal was brought into contact with the silicon chip from the horizontal direction at a speed of 0.5 mm / s using a Nordson Dage 4000, and the load required to shear and peel the silicon chip from the photocurable sheet was measured. The load was divided by the area of ​​the silicon chip to obtain the adhesive strength.

[0111] <Adhesive strength of photocurable resin sheet after post-cure> The photocurable resin sheet was attached to a glass plate (20 x 20 x 1 mm) at 0.5 MPa while being heated at 80°C. A xenon lamp was used to measure the cumulative light intensity (mJ / cm) of 365 nm on a laminate of a photocurable resin sheet (resin layer 30 μm) and glass. 2 ) was irradiated with light so that it reached a specified value. After light irradiation, the laminate of photocurable resin sheet and glass was heated at 120°C while a silicon wafer chip (2 x 2 x 0.5 mm) was pressed vertically against the surface of the photocurable resin sheet with a load of 1.78 kg for 5 seconds, and then post-cured in a 150°C environment for 30 minutes. After leaving it to stand for 2 hours in an environment of 25°C, the terminal was brought into contact with the silicon chip from the horizontal direction at a speed of 0.5 mm / s using a Nordson Dage 4000, and the load required to shear and peel the silicon chip from the photocurable sheet was measured. The load was divided by the area of ​​the silicon chip to obtain the adhesive strength. The adhesive strength of 13 MPa or more was evaluated as ◯, and the adhesive strength of less than 13 MPa was evaluated as ×.

[0112] <DSC calorific value of cured photocurable resin sheet> A xenon lamp is used to apply a prescribed cumulative light dose (mJ / cm2) to a photocurable resin sheet. 2 The photocurable resin sheet (not post-cured) after this light irradiation was heated from 25°C to 225°C at a temperature increase rate of 10°C / min using a differential scanning calorimeter (DSC, DSC6220 manufactured by SII Corporation), the exothermic peak observed after 50°C was measured, and the amount of heat generated was calculated from the measurement results.

[0113] [Table 1]

[0114] From the results in Table 1, it was found that the photocurable resin sheet cured product having an adhesive strength of 13 MPa or more has excellent adhesiveness. Therefore, it was found that the photocurable resin sheet cured product of the present invention is a photocurable resin sheet cured product that can be fixed to a housing with high precision because the adhesive strength is 13 MPa or more. Furthermore, it was found that the manufacturing method of the housing of the present invention is a manufacturing method of the housing including a cured product preparation step of irradiating the photocurable resin sheet with active energy rays to prepare a photocurable resin sheet cured product, and an adhesion step of heating the photocurable resin sheet cured product prepared by the cured product preparation step to adhere to the housing, and therefore the resin cured product can be fixed to the housing with high precision. [Explanation of symbols]

[0115] 11 Mold 12 Base sheet 13. Cabinet 14 Semiconductor elements 100 Liquid photo-radical curable resin composition 101 Photo-curable resin hardened product 102 Adhesive 200 Photocurable resin sheet 201 Photocurable resin sheet hardened product

Claims

1. a cured product preparation step of irradiating the photocurable resin sheet with active energy rays to prepare a photocurable resin sheet cured product; and a bonding step of heating the cured photocurable resin sheet prepared in the cured product preparation step to bond it to a housing.

2. The method for manufacturing a housing according to claim 1 , wherein no adhesive is used in the bonding step.

3. 3. The method for manufacturing a housing according to claim 1, wherein the photocurable resin sheet is a photocationically curable resin sheet.

4. 3. The method for manufacturing a housing according to claim 1, wherein the photocurable resin sheet is a shaped sheet.

5. In the cured product preparation step, the amount of ultraviolet light irradiation is 600 to 25,000 mJ / cm ２ The method for manufacturing a housing according to claim 1 or 2,

6. 3. The method for manufacturing a housing according to claim 1, wherein the cured photocurable resin sheet is an optical material.

7. 3. A photocurable resin sheet for use in the method for manufacturing a housing according to claim 1 or 2.

8. A cured photocurable resin sheet having an adhesive strength of 13 MPa or more when left to stand in a 150°C environment for 30 minutes and then left to stand in a 25°C environment for 2 hours.

9. 9. The photocurable resin sheet cured product according to claim 8, wherein the heat generation amount calculated from the exothermic peak observed after 50°C when heated from 25°C to 225°C at a temperature increase rate of 10°C / min is 100 mJ / mg or more.

10. The photocurable resin sheet cured product according to claim 8 or 9, which is prepared by irradiating a photocationically curable resin sheet with active energy rays.

11. The amount of ultraviolet light irradiation is 600 to 25,000 mJ / cm ２ The photocurable resin sheet cured product according to claim 10, which is

12. The photocurable resin sheet cured product according to claim 8 or 9, which is a shaped sheet.

13. The photocurable resin sheet cured product according to claim 8 or 9, which is an optical material.

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