Resin composition for optical waveguide, resin composition for substrate with optical waveguide, resin film, cured product, and photoelectric substrate

Abstract

The purpose of the present invention is to provide a resin composition suitable for optical communication technology. Furthermore, the purpose of the present invention is to provide a resin composition which can be used as an insulating resin for an electronic redistribution layer or as a cladding resin for a polymer optical waveguide, and which is suitable for filling gaps in order to protect wiring between chips, between chip substrates, etc. Therefore, the high-volume energy-saving multifunctional device can be realized through various packaging structures which are packaged together in a photoelectric manner. As a result of continuous in-depth studies, the present inventors found that a composition containing a photocurable resin and a bismaleimide compound can be used as a resin composition for an optical waveguide, thereby completing the present invention.

Description

Technical Field

[0001] The present invention relates to a resin composition for an optical waveguide, a resin composition for a substrate with an optical waveguide, a resin film, a cured product, and an optical circuit substrate. Background Art

[0002] In recent years, in order to solve the heating problem of circuit boards used in base station servers of communication infrastructure and achieve energy saving, the use of optical circuit boards has been required. However, optical communication is composed of a combination of individual parts, so its high-integration technology has not yet been established.

[0003] Furthermore, in order to achieve high integration technology with the existing circuit substrate (package substrate on which an IC chip is mounted), a technology for co-mounting and packaging electrical and optical wiring (co-packaging) has not yet been established.

[0004] It is known that in conventional circuit boards, a redistribution layer on a package substrate on which a chip is mounted is composed of copper wiring of several micrometers in size derived from copper foil and an insulating resin composition.

[0005] On the other hand, optical fibers with a size of tens of micrometers are used for wiring in photonics (optical communication), but as miniaturization progresses from several micrometers to submicrometers, polymer optical waveguides are expected to be used.

[0006] In order to package optical communications with high density and low power consumption, the integration of a large number of devices is being studied, and the optoelectronic co-packaging technology (Co-Packaged Optics) that simultaneously packages electrical communication technology and optical communication technology is being studied. A package substrate structure has been proposed that miniaturizes optical communication devices that were previously installed as individual parts and integrates them into chip size and then mixes them with electrical communication IC chips.

[0007] Patent Document 1 discloses that in a package substrate mixed with optoelectronic chips made from a III-V compound semiconductor wafer, the difference in coefficient of thermal expansion (CTE) of an IC chip made from a silicon wafer becomes a problem during packaging.

[0008] Patent Document 2 discloses a structure in which photonic chips are packaged in a stacked form of FOWLP (Fan Out Wafer Level Package).

[0009] Patent Document 3 discloses a structure in which a silicon photonics chip having an optical transceiver function is mounted on a substrate.

[0010] The above are all specific structures of optoelectronic co-packaging, which require insulating resin. The insulating resin is a redistribution layer (RDL) used to fill the gaps in order to protect the wiring between chips and between chip substrates.

[0011] Patent Document 4 discloses an epoxy resin composition characterized by optical transmittance as a selective wavelength absorption composition for LIDAR (Laser Imaging Detection and Ranging) having a transmittance of 70% or more at 1550 nm, which has little discoloration due to heat and high stability against light.

[0012] On the other hand, Patent Document 5 discloses that a resin composition containing a bismaleimide resin is suitable for a redistribution layer in electronics.

[0013] Non-patent document 1 discloses the directionality of mounting a package of a small and highly integrated optical communication device on a silicon wafer and a conventional large-scale integrated circuit (LSI chip) on the same substrate.

[0014] [Prior art literature]

[0015] [Patent Document]

[0016] Patent Document 1: U.S. Patent Application Publication No. 2021 / 0088737

[0017] Patent Document 2: U.S. Patent Application Publication No. 2018 / 0275359

[0018] Patent Document 3: U.S. Patent No. 10025047

[0019] Patent Document 4: Japanese Patent No. 6899061

[0020] Patent document 5: International publication No. WO2021 / 154898A2.

[0021] [Non-profit literature]

[0022] Non-patent literature 1: Optoelectronic Packaging Technology Committee, Optoelectronic Packaging Technology Research Group, "Current Status and Future Prospects of Co-Packaged Optics", The Japan Institute of Electronics Packaging, Vol. 24, No. 1, 2021, pp. 38-42. Summary of the invention

[0023] [Problems to be solved by the invention]

[0024] Therefore, it is necessary to consider optical properties such as near-infrared rays, especially the refractive index in the C-Band near the optical communication wavelength of 1550nm, as well as the low dielectric properties required for insulating resins in electronic packaging suitable for high frequencies in recent years. The resin composition of the redistribution layer in the packaging structure of any of the above-mentioned optical communication devices does not take these properties into consideration at the same time.

[0025] The present invention has been studied in view of the above situation, and an object of the present invention is to provide a resin composition suitable for optical communication technology.

[0026] In addition, the purpose is to provide a resin composition that can be used as an insulating resin for an electronic redistribution layer or a cladding resin for a polymer optical waveguide, and is suitable for filling gaps in order to protect wiring between chips, between chip substrates, etc., thereby realizing a highly integrated energy-saving multifunctional device through various packaging structures of optoelectronic co-packaging.

[0027] [Methods to solve the problem]

[0028] The inventors of the present invention have continued to conduct in-depth research and found that a composition containing a photocurable resin and a bismaleimide compound can be used as a resin composition for optical waveguides, thereby completing the present invention. In addition, the present invention provides a resin composition that has both optical properties that can achieve a cladding function suitable for an optoelectronic co-packaging process for simultaneous packaging of optical communications, and low dielectric properties required for insulation of an electronic redistribution layer.

[0029] That is, the present invention relates to the following [1] to

[10] .

[0030] [1] A resin composition for an optical waveguide, comprising a photocurable resin and a bismaleimide compound.

[0031] [2] A resin composition for an optical waveguide, comprising a photocurable resin and a bismaleimide compound represented by the following general formula (1).

[0032]

[0033] (In formula (1), R 1 represents a divalent hydrocarbon group derived from a dimer acid, R 2 represents a divalent organic group other than a divalent hydrocarbon group derived from a dimer acid, R 3 For R 2 or R 1 . R 4 and R 5Each independently contains one or more organic groups selected from a tetravalent organic group having 6 to 40 carbon atoms and having a monocyclic or condensed polycyclic alicyclic structure, a tetravalent organic group having 4 to 40 carbon atoms in which organic groups having a monocyclic alicyclic structure are linked to each other directly or through a crosslinking structure, a tetravalent organic group having 4 to 40 carbon atoms having a semi-alicyclic structure having both an alicyclic structure and an aromatic ring, and a tetravalent organic group having 4 to 40 carbon atoms and having an alicyclic structure or an aromatic ring having a halogenated alkyl group. n is 0 to 100, and m is 0 to 100. However, when n=m=0, R 3 For R 1 )

[0034] [3] The optical waveguide resin composition according to [2], wherein in the bismaleimide compound represented by the above formula (1), R 4 , R 5 The organic group represented is any one of the tetravalent organic groups represented by the following structural formulae (A-1) to (A-13).

[0035]

[0036] (The bond indicated by * in the above structural formula is bonded to the carbonyl carbon forming the cyclic imide structure in the above general formula (1))

[0037] [4] The optical waveguide resin composition according to [2], wherein in the bismaleimide compound represented by the above formula (1), R 4 , R 5 The organic group represented by is any of the tetravalent organic groups represented by the above structural formulas (A-3) to (A-6) and (A-8) to (A-11),

[0038] The dispersion term δd of the Hansen solubility parameter of the aforementioned bismaleimide compound is 16.6 MPa 1 / 2 Above 21.2MPa 1 / 2 Below, the polar term δp is 4.4MPa 1 / 2 Above 9.0MPa 1 / 2 Below, the hydrogen bond term δh is 4.4MPa 1 / 2 Above 9.2MPa 1 / 2 the following.

[0039] [5] A resin composition for a substrate with an optical waveguide, comprising a photocurable resin and a bismaleimide compound represented by the above formula (1).

[0040] [6] The resin composition for a substrate with an optical waveguide according to [5], wherein in the bismaleimide compound represented by the above formula (1), R 4 , R 5 The organic group represented is any of the tetravalent organic groups represented by the above structural formulae (A-1) to (A-13).

[0041] [7] The resin composition for a substrate with an optical waveguide according to [5], wherein in the bismaleimide compound represented by the above formula (1), R 4 , R 5 The organic group represented by is any one of the tetravalent organic groups represented by the above formulae (A-3) to (A-6) and (A-8) to (A-11), and the dispersion term δd of the Hansen solubility parameter of the above bismaleimide compound is 16.6 MPa 1 / 2 Above 21.2MPa 1 / 2 Below, the polar term δp is 4.4MPa 1 / 2 Above 9.0MPa 1 / 2 Below, the hydrogen bond term δh is 4.4MPa 1 / 2 Above 9.2MPa 1 / 2 the following.

[0042] [8] A resin film comprising the resin composition according to any one of [1] to [7].

[0043] [9] A cured product, which is a cured product of the resin composition according to any one of [1] to [7].

[0044]

[10] An optical circuit substrate comprising the cured product described in [9].

[0045] [Effects of the invention]

[0046] According to the present invention, a resin composition suitable for optical communication technology can be provided.

[0047] Furthermore, according to the present invention, there can be provided a resin composition for redistribution of wiring having a cladding function of a polymer waveguide in a co-package of an optoelectronic co-package. DETAILED DESCRIPTION

[0048] The optical waveguide resin composition of the present embodiment will be described. The present invention is not limited to the examples but is defined by the claims, and includes all modifications within the meaning and scope of the equivalents to the claims.

[0049] In the present specification (including Examples etc.), "parts" and "%" are described on a mass basis unless otherwise specified.

[0050] In addition, in this specification, "(meth)acrylate" includes both methacrylate and acrylate.

[0051] The optical waveguide resin composition of the present embodiment contains a photocurable resin and a bismaleimide compound described below.

[0052] <Photocuring resin>

[0053] The photocurable resin may be, for example, a (meth)acrylate having at least one (meth)acryloyl group in the molecule. The (meth)acrylate may be, for example, a (meth)acrylate selected from the group consisting of monofunctional (meth)acrylate, multifunctional (meth)acrylate, multifunctional urethane (meth)acrylate, multifunctional epoxy (meth)acrylate, and multifunctional polyester (meth)acrylate.

[0054] The monofunctional monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, isopentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, 4-tert-butylcyclohexanol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentyl (meth)acrylate, nonylphenol polyethylene glycol (meth)acrylate, isooct ...anyl (meth)acrylate, nonylphenol polyethylene glycol (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, esters; (meth) acrylic acid, (meth) acrylic acid dimer, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, ω-carboxy-polycaprolactone (meth) acrylate and other carboxyl-containing monomers; N-acryloyl Heterocyclic (meth)acrylates such as 1,2-dimethoxy-1,2-dimethyl-1,2-diethyl ... N-substituted amide monomers such as (meth)acrylamide, N-butyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, and N-methylolpropane (meth)acrylamide; (meth)acrylamide alkyl (meth)acrylate monomers such as aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and tert-butylaminoethyl (meth)acrylate; succinimide monomers such as N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide.

[0055] The polyfunctional monomers include, for example, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, di(meth)acrylate of alkylene oxide adduct of bisphenol A, tetraethylene glycol di(meth)acrylate, hydroxytrimethylacetic acid neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,14-tetradecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,20-eicosandiol di(meth)acrylate, isoprene glycol di(meth)acrylate, 3-ethyl-1,8-octanediol di(meth)acrylate, tri(meth)acrylate, bisphenol A EO adduct di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethyloloctane tri(meth)acrylate, trimethylolpropane polyethoxy tri(meth)acrylate, trimethylolpropane polypropoxy tri(meth)acrylate, trimethylolpropane polyethoxy polypropoxy tri(meth)acrylate, tri[(meth)acryloyloxyethyl]isocyanurate, pentaerythritol tri(meth)acrylate, pentaerythritol polyethoxy tetra(meth)acrylate, pentaerythritol polypropoxy tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate and caprolactone-modified tri[(meth)acryloyloxyethyl]isocyanurate.

[0056] Among these, monofunctional and bifunctional (meth)acrylates are more preferred due to their low viscosity. In particular, phenoxy-containing monofunctional epoxy acrylates and 1,6-hexanediol diacrylate are more preferred from the viewpoint of viscosity and compatibility with maleimide resins.

[0057] From the viewpoint of the viscosity of the composition, the content of the monofunctional epoxy acrylate containing a phenoxy group is 10% by weight or less, preferably 1% by weight or less, in 100% by weight of the resin component. In addition, the content of 1,6-hexanediol diacrylate is 3% by weight or more and 25% by weight or less, preferably 20% by weight or more and 25% by weight or less.

[0058] <Bismaleimide Compounds>

[0059] The bismaleimide compound is not particularly limited as long as it has a maleimide structure at both ends of the molecule. The bismaleimide compound preferably has two or more imide structures.

[0060] The bismaleimide compound is preferably a bismaleimide compound represented by the following formula (1).

[0061]

[0062] In the above formula (1), R 1 represents a divalent hydrocarbon group derived from a dimer acid, R 2 represents a divalent organic group other than a divalent hydrocarbon group derived from a dimer acid, R 3 For R 2 or R 1 . R 4 and R 5 Each independently contains one or more organic groups selected from a tetravalent organic group having 6 to 40 carbon atoms and having a monocyclic or condensed polycyclic alicyclic structure, a tetravalent organic group having 4 to 40 carbon atoms in which organic groups having a monocyclic alicyclic structure are linked to each other directly or through a crosslinking structure, a tetravalent organic group having 4 to 40 carbon atoms having a semi-alicyclic structure having both an alicyclic structure and an aromatic ring, and a tetravalent organic group having 4 to 40 carbon atoms and having an alicyclic structure or an aromatic ring having a halogenated alkyl group. n is 0 to 100, and m is 0 to 100. However, when n=m=0, R 3 For R 1 .

[0063] Here, R in the above formula (1) 1 The divalent hydrocarbon group derived from the dimer acid shown here means a divalent residue obtained by removing two carboxyl groups from the dicarboxylic acid contained in the dimer acid.

[0064] In the present embodiment, dimer acid refers to dimerization of unsaturated bonds of unsaturated carboxylic acids with 18 carbon atoms such as linolenic acid, oleic acid, and perilla acid, and then distillation and purification. Dimer acid mainly contains dicarboxylic acids with 36 carbon atoms, and usually contains tricarboxylic acids with 54 carbon atoms (limited to about 5% by mass) and monocarboxylic acids (limited to about 5% by mass). The diamine derived from dimer acid in the present embodiment (hereinafter referred to as diamine derived from dimer acid) is a diamine obtained by replacing the two carboxyl groups possessed by each dicarboxylic acid contained in the aforementioned dimer acid with amino groups. Usually, the diamine derived from dimer acid is a mixture of multiple types. The diamine derived from dimer acid can include, for example, diamines such as [3,4-bis(1-aminoheptyl)6-hexyl-5-(1-octenyl)]cyclohexane, or diamines that saturate the unsaturated bonds by further hydrogenating these diamines.

[0065] The divalent hydrocarbon derived from dimer acid of the present embodiment introduced into the bismaleimide compound using the diamine derived from dimer acid is preferably a residue obtained by removing two amine groups from the aforementioned diamine derived from dimer acid. In addition, when the bismaleimide compound of the present embodiment is obtained using the aforementioned diamine derived from dimer acid, the aforementioned diamine derived from dimer acid can be used alone or in combination with two or more diamines having different compositions. In addition, the diamine derived from dimer acid can use commercial products such as "PRIAMINE 1074" (manufactured by CRODA JAPAN Co., Ltd.).

[0066] In the above formula (1), R 2 The divalent organic group other than the divalent hydrocarbon group derived from the dimer acid shown above is an alkylene group having 6 to 60 carbon atoms which may contain a heteroatom, or an arylene group having 6 to 30 carbon atoms which may contain a heteroatom. More preferably, it is an alkylene group having 8 to 40 carbon atoms which may contain a heteroatom, or an arylene group having 8 to 18 carbon atoms.

[0067] In the above formula (1), R 2 More preferably, it is any of an alkylene group having an aliphatic ring or an arylene group having an aromatic ring represented by the following structural formulas (B-1) to (B-4).

[0068]

[0069] The bond represented by * in the aforementioned structural formulae (B-1) to (B-4) is bonded to the nitrogen atom in formula (1).

[0070] Here, R in the above formula (1) 4 , R 5 The organic groups shown are each independently a tetravalent organic group having a cyclic structure, and are particularly preferably any of the tetravalent organic groups shown in the following structural formulae (A-1) to (A-13).

[0071]

[0072] The bond represented by * in the aforementioned structural formulae (A-1) to (A-13) is bonded to the carbonyl carbon forming the cyclic imide structure in formula (1). In addition, the aforementioned formula (A-10) is a structure derived from tetracarboxylic dianhydride represented by the following structural formula (A-10-A).

[0073]

[0074] In the above formula (1), m is a divalent hydrocarbon group R derived from the dimer acid 1The number of repeating units of m (hereinafter referred to as a structure derived from a dimer acid) represents an integer of 0 to 100. The value of m is particularly preferably 0 to 10 from the viewpoint of suitability for solubility in a developer during development.

[0075] In the above formula (1), n ​​is a divalent organic group R other than the above divalent hydrocarbon group derived from the dimer acid. 2 The number of repeating units (hereinafter referred to as structures derived from organic diamine) of n represents an integer from 0 to 100. As the value of n increases, the flexibility of the resulting cured product deteriorates, resulting in a harder and more brittle resin. From the viewpoint of the flexibility and elastic modulus of the cured product, the value of n is particularly preferably from 0 to 10.

[0076] Furthermore, the bismaleimide compound represented by the above formula (1) may be a random copolymer of the above structure derived from the dimer acid and the above structure derived from the organic diamine, or may be a block copolymer.

[0077] The bismaleimide compound represented by the above formula (1) can be obtained by reacting a diamine derived from a dimer acid, and optionally an organic diamine other than the diamine derived from a dimer acid, tetracarboxylic dianhydride, and maleic anhydride.

[0078] The method of reacting a diamine derived from dimer acid, tetracarboxylic dianhydride, and maleic anhydride, or the method of reacting a diamine derived from dimer acid, an organic diamine, tetracarboxylic dianhydride, and maleic anhydride is not particularly limited, and a well-known method can be appropriately adopted. For example, first, a diamine derived from dimer acid, a tetracarboxylic dianhydride, and an optional organic diamine other than the diamine derived from dimer acid are stirred at room temperature (about 23° C.) for 30 to 60 minutes in a solvent such as toluene, xylene, tetralin, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, or a mixed solvent thereof, thereby synthesizing polyamic acid. Then, maleic acid is added to the obtained polyamic acid and stirred at room temperature (about 23° C.) for 30 to 60 minutes, thereby synthesizing a polyamic acid with maleic acid added to both ends. The polyamic acid is further added with a solvent that azeotropes with water, such as toluene, and refluxed at 100 to 160° C. for 3 to 6 hours while removing water generated by imidization, thereby obtaining the desired bismaleimide compound. In addition, a catalyst such as pyridine or methanesulfonic acid may be further added in this method.

[0079] The bismaleimide compound preferably has a dispersion term δd of 16.6 MPa in the Hansen solubility parameter. 1 / 2 Above 21.2MPa 1 / 2 Below, polar term δp is 4.4MPa 1 / 2 Above 9.0MPa 1 / 2 Below, the hydrogen bond term δh is 4.4MPa 1 / 2 Above 9.2MPa 1 / 2The following bismaleimide compounds.

[0080] The dispersion term δd of the aforementioned Hansen solubility parameter is 16.6 MPa 1 / 2 Above 21.2MPa 1 / 2 Below, polar term δp is 4.4MPa 1 / 2 Above 9.0MPa 1 / 2 Below, the hydrogen bond term δh is 4.4MPa 1 / 2 Above 9.2MPa 1 / 2 The following bismaleimide compounds are preferably bismaleimide represented by the above formula (1). 1 The divalent hydrocarbon group derived from the dimer acid, R 2 The divalent organic groups other than the divalent hydrocarbon group derived from the dimer acid are as described above.

[0081] In addition, if the divalent organic groups other than the divalent hydrocarbon groups derived from the dimer acid increase, the values ​​of δp and δh will increase and easily exceed the aforementioned parameter range. Therefore, the bismaleimide compound satisfying the aforementioned Hansen solubility parameters is preferably a bismaleimide compound wherein m and n in the aforementioned formula (1) are in a ratio of m>n.

[0082] In the bismaleimide compound satisfying the aforementioned Hansen solubility parameters, R 4 , R 5 The organic groups shown are each independently a tetravalent organic group containing a cyclic structure, more preferably a tetravalent organic group having a 6-membered alicyclic skeleton, a tetravalent organic group having an aromatic ring skeleton having a halogenated alkyl group, a tetravalent organic group having a monocyclic or condensed polycyclic alicyclic structure, and an organic group in which organic groups having a monocyclic alicyclic structure are linked to each other directly or through a crosslinked structure. Particularly preferably, it is any of the tetravalent organic groups shown in the following structural formulas (A-3) to (A-6) and (A-8) to (A-11).

[0083]

[0084] The bismaleimide compound of the present embodiment is preferably a compound shown in the following formula (M-1), a compound shown in the following formula (M-2), a compound shown in the following formula (M-3), a compound shown in the following formula (M-4), a compound shown in the following formula (M-5), and a compound shown in the following formula (M-6). In addition, the bismaleimide compound of the present embodiment can be used alone or in combination of two or more. In the following formulas (M-1) to (M-5), from the viewpoint of compatibility, n is preferably 1 to 10, and more preferably 1 to 3.

[0085]

[0086]

[0087] Here, the Hansen solubility parameter refers to the solubility parameter introduced by Hildebrand divided into three terms: dispersion term (δd), polar term (δp), and hydrogen bonding term (δh) and expressed in three-dimensional space. The dispersion term (δd) represents the effect caused by dispersion force, the polar term (δp) represents the effect caused by dipole-dipole force, and the hydrogen bonding term (δh) represents the effect caused by hydrogen bonding force.

[0088] The definition and calculation method of Hansen solubility parameters are described in, for example, "Hansen Solubility Parameters: A ser Handbook" by Charles M. Hansen, CRC Press, 2007. Alternatively, the Hansen Solubility Parameters can be calculated using computer software "Hansen Solubility Parameters in Practice (HSPiP)".

[0089] This time, the bismaleimide compound was mixed with 13 types of organic solvents (N,N-dimethylformamide, ethyl acetate, cyclopentanone, methanol, methyl ethyl ketone, methyl isobutyl ketone, N-methylpyrrolidone, anisole, isopropanol, propylene glycol monomethyl ether acetate, toluene, water, ethylene glycol diglycidyl ether) at a ratio of 1:9 and stirred, and heated in a constant temperature bath at 80°C for 1 hour to make the solution the same and then stand overnight. The miscibility level of the volume after standing overnight was counted from 1 to 6, and the result was substituted into the software and calculated. In the miscibility level in this manual, level 1 means complete miscibility. Level 2 means that it is a transparent solution but has a little turbidity. Level 3 means that the solution is turbid as a whole or part of the compound is precipitated. Level 4 means that the compound swells in the solution as a whole or more than half of the compound is insoluble and precipitates. Level 5 means that the solution is suspended as a whole or only part of the compound is miscible. Level 6 means that the compound is completely insoluble and does not swell or separate. The Hansen solubility parameters in this specification were calculated using HSPiP version 5.4.01.

[0090] From the viewpoint of viscosity and compatibility of the composition, the content of the bismaleimide compound is 60% by weight to 80% by weight, more preferably 70% by weight to 80% by weight, based on 100% by weight of the resin component.

[0091] <Photopolymerization Initiator>

[0092] The optical waveguide resin composition of the present embodiment may contain the photopolymerization initiator described below. The photopolymerization initiator can be appropriately selected from well-known free radical photopolymerization initiators and used. The photopolymerization initiator can include benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether; organic peroxides exemplified by benzoyl peroxide, lauroyl peroxide, acetyl peroxide, p-chlorobenzoyl peroxide, and di-tert-butyl diperphthalate; 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine Phosphine oxides such as benzoyl-diphenyl-phosphine oxide and bisbenzoyl-phenylphosphine oxide; acetophenone, 2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropane-1-one, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2- Linopropane-1-one, and 2-benzyl-2-dimethylamino-1-(4- 1-[4-(phenylthio)phenyl]-1,2-octanedione, 2-(O-benzoyl oxime), ... and oxime esters such as 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone-1-(O-acetyl oxime) or free radical photocuring initiators, or diazonium salts of Lewis acids such as p-methoxyphenyldiazonium fluorophosphonate and N,N-diethylaminophenyldiazonium hexafluorophosphonate; iodonium salts of Lewis acids such as diphenyliodonium hexafluorophosphonate and diphenyliodonium hexafluoroantimonate; sulfonium salts of Lewis acids such as triphenylsulfonium hexafluorophosphonate and triphenylsulfonium hexafluoroantimonate; phosphonium salts of Lewis acids such as triphenylphosphonium hexafluoroantimonate; other halides; triphenylphosphonium hexafluorophosphonate Initiators; borate initiators; other cationic photopolymerization initiators such as photoacid generators.

[0093] As the photopolymerization initiator, commercially available products may be used, and examples thereof include Omnirad (registered trademark) 369 (trade name) manufactured by IGM Resins BV, Omnirad (registered trademark) 819 (trade name) manufactured by IGM Resins BV, Omnirad (registered trademark) 819DW (trade name) manufactured by IGM Resins BV, Omnirad (registered trademark) 907 (trade name) manufactured by IGM Resins BV, Omnirad (registered trademark) TPO (trade name) manufactured by IGM Resins BV, Omnirad (registered trademark) TPO-G (trade name) manufactured by IGM Resins BV, Omnirad (registered trademark) 784 (trade name) manufactured by IGM Resins BV, Irgacure (registered trademark) OXE01 (trade name) manufactured by BASF Japan Co., Ltd., Irgacure (registered trademark) OXE02 (trade name) manufactured by BASF Japan Co., Ltd., and Irgacure (registered trademark) OXE03 (trade name) manufactured by JAPAN Co., Ltd. and Irgacure (registered trademark) OXE04 (trade name) manufactured by BASF JAPAN Co., Ltd. These photocuring initiators (C) may be used alone or in combination of two or more.

[0094] In this embodiment, the C-Band is a near-infrared optical communication signal of 1535-1565nm, which can be used as an example of a wavelength range generally used for optical communications using optical fiber, but does not exclude the use of optical communications in peripheral wavelength ranges such as O-Band, S-Band, and L-Band.

[0095] The cured product of the optical waveguide resin composition can simultaneously achieve two effects: 1) low loss tangent; 2) the refractive index in the C-band (1550nm) is within the range that can be used in optical waveguides. In this specification, the range of refractive index that can be used in optical waveguides refers to a value less than 1.6 that is suitable when the optical waveguide resin composition is used as a cladding material. If the refractive index is 1.6 or more, it is suitable for a core material in an optical waveguide.

[0096] The optical waveguide resin composition may be a resin composition or a resin film. The resin composition has fluidity. The resin composition may be in a paste state. The paste state also includes a liquid state.

[0097] The optical waveguide resin composition is preferably a photocurable material. When the resin composition is a resin film, the resin film is preferably a photocurable resin film.

[0098] The above-mentioned resin composition for optical waveguide is preferably cured by exposure (photocuring). Examples of the exposure light include ultraviolet rays, electron beams, X-rays, and the like. The light source used for ultraviolet irradiation may be sunlight, a chemical lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a UV-LED, and the like. In addition, after exposure, post-baking may be performed to stabilize the physical properties of the cured product. The post-baking method is not particularly limited, and is generally performed using a heating plate, an oven, or the like within a range of 50 to 260°C and 1 to 120 minutes.

[0099] The cured product has a refractive index of about 1.4 at a wavelength of 1,550 nm, and is suitable as an optical waveguide forming material.

[0100] The above-mentioned resin composition for optical waveguide can also be used as a resin composition for substrate with optical waveguide. For example, by embedding a core material in the resin composition for substrate with optical waveguide and forming it into a plate shape, a substrate with optical waveguide having a core material embedded therein can be formed. In this case, the resin composition for substrate with optical waveguide functions as a cladding material in the optical waveguide.

[0101] An optical waveguide or optical circuit board, or a substrate with an optical waveguide produced using the above-mentioned resin composition for an optical waveguide or resin composition for a substrate with an optical waveguide is also an object of the present invention.

[0102] In the optical waveguide of this embodiment, the resin composition can be applied to either a cladding forming material forming the cladding portion of the optical waveguide or a core forming material forming the core portion. However, since the cured product thereof has a low refractive index, it is particularly suitable for the cladding forming material.

[0103] In addition, in the above-mentioned optical waveguide, various materials used in the past for forming the cladding part and the core part of the optical waveguide can be appropriately selected and used, that is, silicone resin, acrylic resin, vinyl resin, epoxy resin, polyimide resin, polyolefin ... The cladding forming material and the core forming material can be selected from the above-mentioned optical waveguide forming composition and various conventional materials so that the refractive index of the cladding part formed by the cladding forming material is lower than that of the central part of the core part formed by the core forming material. In addition, the cladding forming material can contain a light absorbing material such as carbon black.

[0104] In the above optical waveguide, the manufacturing method thereof is not particularly limited. For example, the optical waveguide can be formed by hardening the optical waveguide forming composition of the present embodiment or the above-mentioned various conventional materials by exposure (photohardening) or heating (thermohardening). As a representative example, the optical waveguide can be formed by a development step using a lithography technique using a photomask.

[0105] Furthermore, the optical waveguide forming composition is also suitable for producing a so-called "optical pin" (optical waveguide having a desired tilt angle with respect to a substrate surface) which is one form of an optical waveguide.

[0106] The optical waveguide having the desired tilt angle is preferably produced by the production method described in International Publication No. 2015 / 060190. Specifically, the optical waveguide may be produced by the following methods (1) to (3): (1) providing an antireflection film on a support; (2) disposing the optical waveguide forming composition on the antireflection film, exposing the optical waveguide forming composition to light incident from a non-perpendicular direction with respect to the surface of the support through a photomask, and curing the optical waveguide forming composition; and (3) removing the unexposed optical waveguide forming composition by development.

[0107] The antireflection film is not particularly limited, and a more preferred antireflection film is formed from the antireflection film-forming composition described in the above-mentioned International Publication No. 2015 / 060190 (a polymerizable composition comprising a reactive polysiloxane compound and a UV absorber, wherein the reactive polysiloxane compound is obtained by polycondensing a diaryl siloxane compound of a specific structure and an alkoxysilane compound of a specific structure in the presence of an acid or a base).

[0108] In addition, the above-mentioned optical waveguide forming composition is also suitable for preparing a gradient refractive index type (GI type) optical waveguide, which is obtained by, for example, using the manufacturing method described in International Publication No. 2013 / 002013, that is, a method (so-called mosquito method) of injecting a hardening resin that serves as a core drawn with a distributor wiring into a hardening resin that serves as a cladding.

[0109] (Example)

[0110] [Preparation of resin composition]

[0111] <Bismaleimide Compounds>

[0112] The following four compounds were prepared as bismaleimide compounds.

[0113] (A-1) Bismaleimide compound

[0114] Synthesized according to Synthesis Example 1 of WO2020 / 203834. Mass average molecular weight (Mw): 3200 (Formula (M-3) above)

[0115] (A-2) Bismaleimide compound

[0116] Nippon Kayaku Co., Ltd., trade name "MIZ-001", mass average molecular weight (Mw): 3000 (the above formula (M-1))

[0117] (A-3) Bismaleimide compound

[0118] Compound (A3) was synthesized according to Synthesis Example 4 of WO2020 / 203834. Mass average molecular weight (Mw): 3700 (Formula (M-2) above)

[0119] (A-4) Bismaleimide compound

[0120] Designer Molecules Inc., trade name "BMI-689", mass average molecular weight (Mw): 690 (Formula (M-6) above)

[0121] <Monomer of Photocurable Resin>

[0122] As monomers of the photocurable resin, an epoxy acrylate monomer having a phenoxy group (manufactured by Nippon Kayaku Co., Ltd., trade name “R-128H”) and 1,6-hexanediol diacrylate (HDDA) (manufactured by IGM Resins BV, trade name “photomer 4017”) were prepared.

[0123] <Photopolymerization Initiator>

[0124] As a photopolymerization initiator, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by IGM Resins B.V., trade name "Omnirad TPO") was prepared.

[0125] <Resin composition>

[0126] The bismaleimide compound, a monomer of a photocurable resin, and a photopolymerization initiator are mixed to prepare a resin composition.

[0127] In Table 1, the values ​​of maleimide compounds (A-1) to (A-4), monomers of photocurable resins (R-128H, HDDA) and photopolymerization initiators (TPO) are the contents (mass %) based on the total amount of maleimide compounds, monomers of photocurable resins and photopolymerization initiators.

[0128] [Production of resin film]

[0129] The resin composition was sandwiched between a 5 mm thick glass substrate to which a 75 μm thick untreated PET film (Teijin's trade name "Teijin Tetoron (registered trademark) film, HSL type") was adhered, and a 100 μm spacer was used to adjust the film thickness. A high pressure mercury lamp (80 W / cm, ozone-free) was used at 1800 mJ / cm 2 The resin film is hardened.

[0130] The obtained resin film was used to perform the following evaluation.

[0131] <Hansen Solubility Parameters>

[0132] The dispersion term (δd), polar term (δp), and hydrogen bonding term (δh) of the Hansen solubility parameters of maleimide compounds (A-1) to (A-4) were calculated using HSPiP version 5.4.01.

[0133] <Compatibility>

[0134] The evaluation of the appearance of the resin film was "○" when it was transparent and not turbid, and "×" when it was turbid.

[0135] <Dielectric constant and loss tangent>

[0136] The resin film was cut into pieces of 80 mm in length and 3 mm in width to prepare test pieces, and the dielectric properties (dielectric constant and loss tangent) were measured by a cavity resonator perturbation method using a 10 GHz cavity resonator manufactured by ATE Corporation.

[0137] <Refractive Index>

[0138] The resin film was cut into 50 mm square pieces as test pieces, and the reflectance of light with a wavelength of 1550 nm was measured. The refractive index was calculated from the reflectance using the Fresnel equation.

[0139] [Table 1]

[0140] Example 1 Example 2 Example 3 Example 4 A-1 71.33 - - - A-2 - 71.33 - - A-3 - - 71.33 - A-4 - - - 71.33 R-128H 0.99 0.99 0.99 0.99 HDDA 24.77 24.77 24.77 24.77 TPO 2.91 2.91 2.91 2.91 δd 17.70 17.60 18.00 16.70 δp 6.50 7.60 6.90 8.40 δh 5.50 6.70 4.40 6.90 Compatibility ○ ○ ○ ○ Dielectric constant 2.54 2.58 2.56 2.56 Loss tangent 0.0077 0.0074 0.0075 0.0075 Refractive index (1550nm) 1.462 1.462 1.469 1.469

[0141] (Industrial Applicability)

[0142] The present invention provides a resin group for optical waveguides, which has a refractive index suitable for optical waveguides at 1550nm as a cladding material for polymer optical waveguides, and can be used to achieve high integration of optoelectronic co-packaging in which low-power optical communications are mounted on electrical communication substrates. In addition, a resin composition for a redistribution layer for optical component mixed packaging is provided, which has a refractive index suitable for optical waveguides and a low dielectric property required for a redistribution layer (RDL) when packaging electronic IC chips.

[0143] This application claims priority based on Japanese Patent Application No. 2022-079430 filed on May 13, 2022.

Claims

1. A resin composition for an optical waveguide, comprising a photocurable resin and a bismaleimide compound.

2. A resin composition for an optical waveguide, comprising a photocurable resin and a bismaleimide compound represented by the following general formula (1), In formula (1), R 1 represents a divalent hydrocarbon group derived from a dimer acid, R 2 represents a divalent organic group other than a divalent hydrocarbon group derived from a dimer acid, R 3 For R 2 or R 1 , R 4 and R 5 Each of the organic groups independently contains one or more organic groups selected from a tetravalent organic group having 6 to 40 carbon atoms and having a monocyclic or condensed polycyclic alicyclic structure, a tetravalent organic group having 4 to 40 carbon atoms in which organic groups having a monocyclic alicyclic structure are linked to each other directly or via a crosslinked structure, a tetravalent organic group having 4 to 40 carbon atoms having a semi-alicyclic structure having both an alicyclic structure and an aromatic ring, and a tetravalent organic group having 4 to 40 carbon atoms and having an alicyclic structure or an aromatic ring having a halogenated alkyl group, wherein n is 0 to 100 and m is 0 to 100, but when n=m=0, R 3 For R 1 .

3. The optical waveguide resin composition according to claim 2, wherein in the bismaleimide compound represented by the formula (1), R 4 , R 5 The organic group represented by is any one of the tetravalent organic groups represented by the following structural formulas (A-1) to (A-13), The bond indicated by * in the above structural formula is bonded to the carbonyl carbon forming the cyclic imide structure in the above general formula (1).

4. The optical waveguide resin composition according to claim 2, wherein in the bismaleimide compound represented by the formula (1), R 4 , R 5 The organic group represented by is any of the tetravalent organic groups represented by the following structural formulas (A-3) to (A-6) and (A-8) to (A-11), The dispersion term δd of the Hansen solubility parameter of the aforementioned bismaleimide compound is 16.6 MPa 1 / 2 Above 21.2MPa 1 / 2 Below, the polar term δp is 4.4MPa 1 / 2 Above 9.0MPa 1 / 2 Below, the hydrogen bond term δh is 4.4MPa 1 / 2 Above 9.2MPa 1 / 2 the following, The bond indicated by * in the above structural formula is bonded to the carbonyl carbon forming the cyclic imide structure in the above general formula (1).

5. A resin composition for a substrate with an optical waveguide, comprising a photocurable resin and a bismaleimide compound represented by the following general formula (1): In formula (1), R 1 represents a divalent hydrocarbon group derived from a dimer acid, R 2 represents a divalent organic group other than a divalent hydrocarbon group derived from a dimer acid, R 3 For R 2 or R 1 , R 4 and R 5 Each of the organic groups independently contains one or more organic groups selected from a tetravalent organic group having 6 to 40 carbon atoms and having a monocyclic or condensed polycyclic alicyclic structure, a tetravalent organic group having 4 to 40 carbon atoms in which organic groups having a monocyclic alicyclic structure are linked to each other directly or via a crosslinked structure, a tetravalent organic group having 4 to 40 carbon atoms having a semi-alicyclic structure having both an alicyclic structure and an aromatic ring, and a tetravalent organic group having 4 to 40 carbon atoms and having an alicyclic structure or an aromatic ring having a halogenated alkyl group, wherein n is 0 to 100 and m is 0 to 100, but when n=m=0, R 3 For R 1 .

6. The resin composition for a substrate with an optical waveguide according to claim 5, wherein in the bismaleimide compound represented by the general formula (1), R 4 , R 5 The organic group represented by is any one of the tetravalent organic groups represented by the following structural formulas (A-1) to (A-13), The bond indicated by * in the above structural formula is bonded to the carbonyl carbon forming the cyclic imide structure in the above general formula (1).

7. The resin composition for a substrate with an optical waveguide according to claim 5, wherein in the bismaleimide compound represented by the general formula (1), R 4 , R 5 The organic group represented by is any of the tetravalent organic groups represented by the following structural formulas (A-3) to (A-6) and (A-8) to (A-11), The dispersion term δd of the Hansen solubility parameter of the aforementioned bismaleimide compound is 16.6 MPa 1 / 2 Above 21.2MPa 1 / 2 Below, the polar term δp is 4.4MPa 1 / 2 Above 9.0MPa 1 / 2 Below, the hydrogen bond term δh is 4.4MPa 1 / 2 Above 9.2MPa 1 / 2 the following, The bond indicated by * in the above structural formula is bonded to the carbonyl carbon forming the cyclic imide structure in the above general formula (1). 8 . A resin film comprising the resin composition according to claim 1 . 9 . A cured product, which is a cured product of the resin composition according to claim 1 . 10 . An optical circuit substrate comprising the cured product according to claim 9 .

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