JP2005164651A - Light guide and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light guide having high heat resistance and low optical loss, and to provide a method for manufacturing the light guide at a high productivity in an easily fabricating procss. <P>SOLUTION: The light guide has a core layer and/or a clad layer formed by using a photosensitive resin composition containing 0.001 to 5 pts.wt. of a photoacid generating agent with respect to 100 pts.wt. of a polyamide resin having a repeating unit expressed by general formula (1). The method for manufacturing the light guide is also presented. In formula (1), each of X and Y represents an organic group, Z is selected from ≤10C organic groups and hydrogen with ≥10% proportion of ≤10C organic groups, and n is an integer 5 to 10,000. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical waveguide and a method for manufacturing the same.

  Conventionally, materials such as glass (quartz) and plastic have been studied as materials for optical waveguides. Among them, optical waveguides made of quartz have low loss and high heat resistance. Used in fields such as optical interconnection and optical communication devices. However, the conventional quartz optical waveguide has a problem in productivity because a long process is required for manufacturing, and a high heat treatment at around 1000 ° C. is required in the manufacturing process. In addition to adverse effects, there are problems that it is difficult to increase the area.

  On the other hand, optical waveguides made of plastic are easier to fabricate and increase in area than quartz optical waveguides, and plastic optical waveguides using polymers such as polymethyl methacrylate, polycarbonate, and UV-curable resins are being investigated. . In these plastic optical waveguides, the heat resistance of the constituent material is around 100 ° C., so the usage environment is limited, and when incorporated as a mounting circuit, it is necessary to pass a soldering process of several hundred ° C. There was a problem with the heat resistance of the optical waveguide.

  Therefore, an attempt has been made to use a polyimide resin having a heat resistance of 300 ° C. or more although it is a plastic material for a plastic optical waveguide. However, in the current polyimide, due to its unique molecular structure, absorption caused by the structure. The optical loss due to was very large. In addition, in the case of using a resin having high crystallinity in the polyimide resin, there is little influence when the film thickness is thin, but when the film thickness used for the optical waveguide is reached, the film becomes brittle or the refractive index is low. There was a change.

Polybenzoxazole resins have been researched and developed for heat resistance applications and electronic applications from heat resistance and low hygroscopicity that surpass polyimide resins. Recently, attempts have been made to apply them as optical waveguide materials (for example, patents). Reference 1). However, as the manufacturing method, processing by dry etching that is not suitable for mass production is used, and there is a problem in terms of mass production cost.
Japanese Patent Laid-Open No. 2002-173532 (page 8-10)

  The present invention has been made as a result of intensive studies in view of the above-described conventional problems, and provides an optical waveguide having high heat resistance and low optical loss, and a method for manufacturing the optical waveguide with ease and high productivity. For the purpose.

That is, the present invention
1. A core layer formed using a photosensitive resin composition containing 0.001 to 5 parts by weight of a photoacid generator with respect to 100 parts by weight of a polyamide resin having a repeating unit represented by the general formula (1) and / or Or an optical waveguide having a cladding layer,

（式（１）中、ＸおよびＹはそれぞれ有機基を示し、Ｚは炭素数１０以下の有機基および水素から選ばれるものであり、前記炭素数１０以下の有機基である割合は１０％以上であり、ｎは５〜１０，０００の整数である。）

(In the formula (1), X and Y each represents an organic group, Z is selected from an organic group having 10 or less carbon atoms and hydrogen, and the proportion of the organic group having 10 or less carbon atoms is 10% or more. And n is an integer of 5 to 10,000.)

2. A step of forming a resin layer using a photosensitive resin composition containing 0.001 to 5 parts by weight of a photoacid generator with respect to 100 parts by weight of a polyamide resin having a repeating unit represented by the general formula (1), Production of optical waveguide including a step of forming a photomask layer on the resin layer and patterning the optical waveguide by light irradiation, a step of removing the patterned resin layer with a developer, and a step of heat curing the resin layer A method is provided.

  According to the present invention, an optical waveguide having excellent heat resistance, electrical characteristics, mechanical characteristics, and colorless transparency, having a small optical loss can be provided, and can be manufactured simply and with high productivity.

  The present invention provides a core layer using a photosensitive resin composition containing 0.001 to 5 parts by weight of a photoacid generator with respect to 100 parts by weight of a polyamide resin having a repeating unit represented by the general formula (1). An optical waveguide formed by forming a cladding layer. The polyamide resin has a structure in which 10% or more of the hydroxyl groups are protected with an organic group, and the photoacid generator generates acid upon receiving light irradiation. In the production of the optical waveguide of the present invention, when patterning the core layer and the clad layer by light irradiation, the acid generated from the photoacid generator dissociates the protecting group of the hydroxyl group of the polyamide resin, thereby causing an alkaline developer. Solubility is expressed and patterning is possible.

The polyamide resin having a repeating unit represented by the general formula (1) used in the present invention is an organic group in which 10% or more of the hydroxyl groups of the polyhydroxyamide resin which is a polybenzoxazole resin precursor is 10 or less carbon atoms. It is protected. The synthesis method is not particularly limited, and examples thereof include a method of esterifying a hydroxyl group of a prepolymerized polyhydroxyamide resin.
In addition to the ester bond, an ether bond, a carbonate bond, or the like can be applied as the protective group.

  In the present invention, the organic group serving as a protective group is an organic group having 10 or less carbon atoms, an alkyl group such as a methyl group, an ethyl group, and an isopropyl group, a cycloalkyl group such as a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group, Aryl group such as phenyl group, p-toluyl group, aralkyl group such as benzyl group and phenylethyl group, alkylcarbonyl group such as acetyl group, propionyl group, butyryl group, oxacycloalkyl group such as tetrahydrofuranyl group, methoxymethyl group Alkoxyalkyl groups such as 1-methoxyethyl group, cycloalkylcarbonyl groups such as cyclohexylcarbonyl group, arylcarbonyl groups such as benzoyl group, alkoxycarbonyl groups such as isopropoxycarbonyl group, t-butoxycarbonyl group and acrylic groups. Yl group, methacryloyl group, cinnamoyl group and the like. These protecting groups can be used alone or in combination.

  In the polyamide resin used in the present invention, the substitution rate of the hydroxyl group to hydrogen to the protecting group is 10% or more, but considering the solubility and developability after exposure, a substitution rate of 20 to 50% is preferable. If the substitution rate is less than 10%, a sufficient dissolution inhibiting effect cannot be obtained, which is not preferable.

  The polyhydroxyamide resin used in the present invention can be obtained by synthesis from a bisaminophenol compound or diaminodihydroxy compound and a dicarboxylic acid by an acid chloride method, an activated ester method, or the like.

  Examples of the bisaminophenol compound and diaminohydroxy compound used in the present invention include 4,4′-diamino-3,3′-dihydroxybiphenyl, 3,3′-diamino-4,4′-dihydroxybiphenyl, and 3,4. '-Diamino-4,3'-dihydroxybiphenyl, bis (4-amino-3-hydroxyphenyl) ether, bis (3-amino-4-hydroxyphenyl) ether, bis (3-amino-4-hydroxyphenyl) sulfide Bis (4-amino-3-hydroxyphenyl) sulfide, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino-3-hydroxyphenyl) sulfone, bis (3-amino-4-hydroxyphenyl) ) Ketone, bis (4-amino-3-hydroxyphenyl) ketone, (3-amino-4-hydroxyphenyl) methane, bis (4-amino-3-hydroxyphenyl) methane, bis (3-amino-4-hydroxy-5-methylphenyl) methane, 2,2-bis (3 -Amino-4-hydroxyphenyl) propane, 2,2-bis (4-amino-3-hydroxyphenyl) propane, 2,2-bis (3-amino-4-hydroxy-5-methylphenyl) propane, 2, 2-bis (4-amino-3-hydroxyphenyl) hexafluoropropane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2-bis (2-amino-3-hydroxyphenyl) ) Hexafluoropropane, 2,2-bis (3-amino-2-hydroxyphenyl) hexafluoropropane, 4,4′-bis ( -Amino-3-hydroxyphenoxy) biphenyl, 4,4'-bis (3-amino-4-hydroxyphenoxy) biphenyl, 3,4'-bis (4-amino-3-hydroxyphenoxy) biphenyl, 3,4 ' -Bis (3-amino-4-hydroxyphenoxy) biphenyl, 3,3'-bis (4-amino-3-hydroxyphenoxy) biphenyl, 3,3'-bis (3-amino-4-hydroxyphenoxy) biphenyl, 1,3-diamino-4,6-dihydroxybenzene, 1,4-diamino-3,6-dihydroxybenzene, 2,7-diamino-3,6-dihydroxynaphthalene, 2,6-diamino-3,7-dihydroxy Naphthalene, 1,6-diamino-2,5-dihydroxynaphthalene, 3,6-diamino-2,5-dihydroxynaphth Talen, 2,7-diamino-1,8-dihydroxynaphthalene, 1,2-bis (4-amino-3-hydroxyphenoxy) benzene, 1,2-bis (3-amino-4-hydroxyphenoxy) benzene, , 3-bis (4-amino-3-hydroxyphenoxy) benzene, 1,3-bis (3-amino-4-hydroxyphenoxy) benzene, 1,4-bis (4-amino-3-hydroxyphenoxy) benzene, 1,4-bis (3-amino-4-hydroxyphenoxy) benzene, 9,9-bis-((4-amino-3-hydroxy) phenyl) fluorene, 9,9-bis-((3-amino-4 -Hydroxy) phenyl) fluorene etc. and any hydrogen atom on the benzene ring of these compounds is a fluorine atom, a chlorine atom, an alkyl group having 10 or less carbon atoms, carbon Although what was substituted by any of the alkoxy group of several tens or less, a vinyl group, an allyl group, an ethynyl group, a phenyl ethynyl group, and a C10 or less perfluoroalkyl group can be mentioned, It is not limited to these. . These diaminodihydroxy compounds and bisaminophenol compounds can be used alone or in combination.

  Examples of the dicarboxylic acid used in the present invention include phthalic acid, isophthalic acid, terephthalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and 1,9-nonanedicarboxylic acid. , Dodecanedioic acid, tridecanedioic acid, 1,12-dodecanedicarboxylic acid, tetrafluorosuccinic acid, hexafluoroglutaric acid, octafluoroadipic acid, perfluoropimelic acid, perfluorosuberic acid, perfluoroazeline acid, perfluoro Sebacic acid, 1,9-perfluorononanedicarboxylic acid, perfluorododecanedioic acid, perfluorotridecanedioic acid, 1,12-perfluorododecanedicarboxylic acid, tetrachlorosuccinic acid, hexachloroglutaric acid, octachloroadipic acid, Perchloropimelic acid, -Chlorosuberic acid, perchloroazelineic acid, perchlorosebacic acid, 1,9-perchlorononanedicarboxylic acid, perchlorododecanedioic acid, perchlorotridecanedioic acid, 1,12-perchlorododecanedicarboxylic acid, 1,4- Perfluorocyclohexanedicarboxylic acid, 1,3-perfluorocyclohexanedicarboxylic acid, 1,2-perfluorocyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-perchlorocyclohexanedicarboxylic acid, 1,3-perchlorocyclohexanedicarboxylic acid, 1,2-perchlorohexanedicarboxylic acid, 4,4′-dicarboxybiphenyl, 3,3′-dicarboxybiphenyl, 3, 4'-Zical Xibibiphenyl, 4,4′-oxybisbenzoic acid, 3,3′-oxybisbenzoic acid, 3,4′-oxybisbenzoic acid, 2,4′-oxybisbenzoic acid, 3,4′-oxybisbenzoic acid, 2, 3′-oxybisbenzoic acid, bis (4-carboxyphenyl) -sulfide, bis (3-carboxyphenyl) -sulfide, bis (4-carboxyphenyl) -sulfone, bis (3-carboxyphenyl) -sulfone, bis (4 -Carboxyphenyl) -ketone, bis (3-carboxyphenyl) -ketone, bis (4-carboxyphenyl) -methane, bis (3-carboxyphenyl) -methane, 2,2-bis (4-carboxyphenyl) -propane 2,2-bis (3-carboxyphenyl) -propane, 2,2-bis (4-carboxyphenyl) -Hexafluoropropane, 2,2-bis (3-carboxyphenyl) -hexafluoropropane, 4,4'-bis (4-carboxyphenoxy) biphenyl, 4,4'-bis (3-carboxyphenoxy) biphenyl, 3, , 4′-bis (4-carboxyphenoxy) biphenyl, 3,4′-bis (3-carboxyphenoxy) biphenyl, 3,3′-bis (4-carboxyphenoxy) biphenyl, 3,3′-bis (3- Carboxyphenoxy) biphenyl, 1,4-dicarboxynaphthalene, 1,5-dicarboxynaphthalene, 1,6-dicarboxynaphthalene, 1,7-dicarboxynaphthalene, 1,8-dicarboxynaphthalene, 2,5-di Carboxynaphthalene, 2,6-dicarboxynaphthalene, 2,7-dicarboxynaphthalene 1,2-bis (4-carboxyphenoxy) benzene, 1,2-bis (3-carboxyphenoxy) benzene, 1,3-bis (4-carboxyphenoxy) benzene, 1,3-bis (3-carboxyphenoxy) ) Benzene, 1,4-bis (4-carboxyphenoxy) benzene, 1,4-bis (3-carboxyphenoxy) benzene, 1,3-bis (3-carboxypropyl) tetramethyldisiloxane, 1,3-bis (3-carboxypropyl) tetraphenyldisiloxane, α, ω-bis (3-carboxypropyl) polydimethylsiloxane, α, ω-bis (3-carboxypropyl) polydiphenylsiloxane and the like on the benzene ring of these compounds Arbitrary hydrogen atoms are fluorine atoms, chlorine atoms, alkyl groups having 10 or less carbon atoms, carbon atoms having 10 or less carbon atoms Although the thing substituted by any of the following alkoxy groups, a vinyl group, an allyl group, an ethynyl group, a phenylethynyl group, and a C10 or less perfluoroalkyl group can be mentioned, It is not limited to these. These dicarboxylic acids can be used alone or in combination.

  In the polyamide resin used in the present invention, examples of the compound used for forming the protective group include dimethyl sulfate, ethyl p-toluenesulfonate, isopropyl methanesulfonate, cyclobutyl p-toluenesulfonate, and cyclohexyl methanesulfonate. , Phenyl p-toluenesulfonate, benzyl methanesulfonate, phenyl p-toluenesulfonate, methoxymethyl methanesulfonate, tetrahydrofuryl p-toluenesulfonate, acetyl chloride, propionyl chloride, butyryl chloride, cyclohexylcarboxylic acid chloride, benzoyl chloride , Diisopropyl dicarbonate, di-t-butyl dicarbonate, acryloyl chloride, methacryloyl chloride, cinnamoyl chloride, and the like. Not intended to be constant. These raw materials can be used alone or in combination.

  As an example of a method for producing a polyhydroxyamide resin used in the present invention, for example, in the acid chloride method, first, the dicarboxylic acid is first mixed with an excess amount of thionyl chloride in the presence of a catalyst such as N, N-dimethylformamide from room temperature. The reaction is carried out at 75 ° C., and excess thionyl chloride is distilled off by heating and reduced pressure. Then, dicarboxylic acid chloride can be obtained by recrystallizing the residue with a solvent such as hexane. Next, the bisaminophenol compound or diaminodihydroxy compound is dissolved in a polar solvent such as N-methyl-2-pyrrolidone, and in the presence of an acid acceptor such as pyridine, the dicarboxylic acid chloride obtained above and −30 ° C. The polyhydroxyamide resin can be obtained by reacting at room temperature.

  Next, as a method for replacing 10% or more of the hydrogen of the hydroxyl group of the polyhydroxyamide resin with an organic group having 10 or less carbon atoms, the polyhydroxyamide resin obtained above is dissolved in an organic solvent such as tetrahydrofuran, and pyridine is used. In the presence of a basic catalyst such as triethylamine, the reaction is carried out at −30 ° C. to room temperature with the acid chloride of the compound used to form the protecting group obtained in the same manner as in the method for producing the acid chloride of the dicarboxylic acid. Thus, a polyamide resin having a structure in which the hydrogen of the hydroxyl group is protected by an ester bond can be synthesized. As in this example, a polyamide resin having a repeating unit represented by the general formula (1) can be synthesized by a reaction between a polyhydroxyamide resin and a compound used to form a protective group, but a protective group is formed. As the compound used for the purpose, an active ester or an acid anhydride can be used in addition to the acid chloride.

  The photoacid generator used in the present invention is not particularly limited as long as it can generate Bronsted acid or Lewis acid by absorbing light energy. For example, triphenylsulfonium trifluoromethanesulfonate, tris (4-t-butyl) can be used. Sulfonium salts such as phenyl) sulfonium-trifluoromethanesulfonate, diazonium salts such as p-nitrophenyldiazonium hexafluorophosphate, ammonium salts, phosphonium salts, diphenyliodonium trifluoromethanesulfonate, (triccumyl) iodonium-tetrakis (pentafluorophenyl) borate, etc. Iazonium salts, quinonediazides, diazomethanes such as bis (phenylsulfonyl) diazomethane, 1-phenyl-1- (4-methylpheny ) Sulfonic acid esters such as sulfonyloxy-1-benzoylmethane and N-hydroxynaphthalimide-trifluoromethanesulfonate, disulfones such as diphenyldisulfone, tris (2,4,6-trichloromethyl) -s-triazine, 2 Examples include compounds such as triazines such as-(3.4-methylenedioxyphenyl) -4,6-bis- (trichloromethyl) -s-triazine. These photoacid generators can be used alone or in combination.

  The addition amount of the photoacid generator in the photosensitive resin composition used in the present invention can be in the range of 0.001 to 5 parts by weight with respect to 100 parts by weight of the polyamide resin. If it is less than this, solubility in an alkaline developer cannot be obtained, and if it is too much, the light loss value increases, which is not preferable. In view of the balance between the developability of the resin layer and the optical loss value of the optical waveguide in the optical waveguide manufacturing process, the addition amount is preferably 0.1 to 3 parts by weight.

  In addition to the above components, the photosensitive resin composition used in the present invention includes a sensitizer, a dissolution inhibitor, a dissolution accelerator, an adhesion assistant, an antioxidant, an antifoaming agent, a leveling agent, and the like as necessary. Additives can be added.

  The photosensitive resin composition used for this invention can be manufactured by mixing the said component using mixers, such as a stirrer, a blender, a static mixer, a kneader.

  In the production of the optical waveguide of the present invention, the photosensitive resin composition is preferably dissolved in an organic solvent and used as a solution. Examples of the organic solvent include methanol, ethanol, 1-propanol, 2-propanol, acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, tetrahydrofuran, dioxane, 2-methoxyethanol, 2-butoxyethanol, propylene glycol monomethyl ether acetate, Examples include diethylene glycol monomethyl ether, ethyl acetate, γ-butyrolactone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, dichloromethane, and chloroform. It is done. These solvents may be used alone or in combination. Among these solvents, tetrahydrofuran, γ-butyrolactone, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone, which are excellent in solubility of the polyamide resin, are preferable.

In the production of the optical waveguide of the present invention, an optical waveguide patterning method using the photosensitive resin composition obtained above will be described with reference to FIG.
As an example of the optical waveguide patterning method of the present invention, first, the resin layer 2 is formed on the substrate 1 by casting the solution of the photosensitive resin composition obtained above. Examples of the casting application method include a bar coating method using a doctor blade or the like, a spin coating method, a printing method using a screen or a stencil, and the like. Examples of the substrate 1 include a silicon wafer, a glass plate, a ceramic plate, an optical crystal plate, a copper-clad laminate, a flexible circuit board, a copper foil, a polyimide resin film, and a polybenzoxazole resin film.
Here, when the resin layer 2 formed on the base material 1 is patterned as it is and used as an optical waveguide, the base material 1 has a refractive index and transparency functioning as a clad, or another base material. A film on which a clad layer is previously laminated can be used.

  Next, the resin layer 2 on the substrate 1 is dried at a temperature of room temperature to 150 ° C. to obtain a tack-free resin layer 2. Examples of the drying method include a method using an oven, a hot plate, a ceramic heater, and the like. Each can use a continuous apparatus or a batch apparatus.

  Next, light exposure is performed by the exposure machine 4 through the photomask 3 on which the optical waveguide pattern is formed on the resin layer 2 dried as described above, and the optical waveguide is patterned on the resin layer 2 (FIG. 1A). )). As a photomask pattern, the unexposed portion of the resin layer 2 is left as a core portion, and a pattern for later use in a method of laminating an upper clad, and the unexposed portion is left as a clad portion, and further a core layer Two types of patterns for use in the method of sequentially laminating the upper cladding layer can be used. As the light source in the light irradiation, for example, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a deep UV lamp, a metal halide lamp, a semiconductor laser, an excimer laser, or the like can be used.

Further, the resin layer 2 patterned as described above may be subjected to heat treatment before development, if necessary.
Next, when the patterned resin layer 2 is developed with an alkaline developer, only the exposed portion is dissolved, and an optical waveguide pattern is obtained (FIG. 1B). Examples of the alkaline developer include aqueous solutions of quaternary ammonium compounds such as tetramethylammonium hydride, inorganic bases such as sodium hydroxide, inorganic salts such as potassium carbonate, amines such as triethylamine, and the like. Further, an organic solvent such as alcohol or ketone can be used. Examples of the development method include a paddle method, a dip method, and a spray method.

  Next, the pattern obtained by development is subjected to heat treatment for final curing after washing with water and drying. Before this step, the entire surface may be irradiated with light as necessary. Final curing is performed for the purpose of removing the solvent and producing a polybenzoxazole resin by dehydration ring closure, and the maximum heating temperature can be in the range of 280 to 400 ° C. If the temperature is too low, the ring closure is insufficient, and if it is too high, the light loss value increases, which is not preferable.

The above is the patterning method of the optical waveguide pattern using the photosensitive resin composition as the gist of the present invention. Next, an example of manufacturing a three-layer embedded optical waveguide will be described with reference to FIG.
First, a polyhydroxyamide resin solution, which is a polybenzoxazole resin precursor to be a lower clad, is applied onto a silicon wafer 5 by spin coating, pre-dried, and then heat-cured to form the lower clad layer 6. . On top of that, a solution of the photosensitive resin composition is spin-coated to form a resin layer (core layer) 7 (FIG. 2C), pre-dried, and a method for patterning the optical waveguide pattern. In the same manner as described above, after patterning the waveguide on the resin layer, the resin layer 7 is cured by heating and left undeveloped as a core (FIG. 2D). Further, the same material as that of the lower cladding layer is applied thereon, preliminarily dried and then heat-cured to form the upper cladding layer 8 (FIG. 2E), and a three-layer buried waveguide is formed. Can be manufactured.

  In the present invention, as a material for forming the clad layer and the core layer, a material is selected in which the core layer has a higher refractive index than the clad layer after the resin layer is finally cured. For example, in a single mode optical waveguide, the refractive index difference is generally 0.3 to 1.5%, and in a multimode optical waveguide, it is generally 1% or more. The method for adjusting the refractive index is not particularly limited, but can be controlled by the composition ratio of the raw material monomers of the polybenzoxazole resin.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited at all by these.

In addition, the raw material used by an Example and a comparative example was shown with the following abbreviation.
B-AP: 1,4-bis (trifluoromethyl) -2,5-diamino-3,6-hydroxybenzene 6F-AP: 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane BF -AP: 3,3'-diamino-4,4'-dihydroxybiphenyl I-CC: isophthalic acid dichloride O-CC: 4,4'-oxybisbenzoic acid dichloride 6F-CC: 2,2'-bis (4- Carboxyphenyl) -hexafluoropropane dicarboxylic acid chloride
BC: benzoyl chloride BU-C: butyryl chloride TB-CA: di-t-butyl dicarbonate TC-I: (triccumyl) iodonium-tetrakis (pentafluorophenyl) borate TT-S: tris (4-t-butyl Phenyl) sulfonium-trifluoromethanesulfonate NI-S: N-hydroxynaphthalimide-trifluoromethanesulfonate TEA: triethylamine NMP: N-methyl-2-pyrrolidone GBL: gamma butyrolactone THF: tetrahydrofuran

(Synthesis of polyhydroxyamide resin PHA-1A)
276.1 parts by weight (1.0 mol) of B-AP was dissolved in 1104 parts by weight of dried NMP, 197.8 parts (2.5 mol) of pyridine was added, and then NMP of 1528 parts by weight at −15 ° C. under dry nitrogen. A solution prepared by dissolving 38.6 parts by weight (0.19 mol) of I-CC and 343.3 parts by weight (0.8 mol) of 6F-CC was added dropwise over 30 minutes. After completion of the dropping, the temperature was returned to room temperature and stirred at room temperature for 5 hours. Thereafter, the reaction solution was dropped into a large amount of ion-exchanged water, re-precipitated, and the precipitate was collected and dried to obtain 575 parts by weight of a polyhydroxyamide resin PHA-1A. When the molecular weight of the precursor obtained using gel permeation chromatography (hereinafter abbreviated as GPC) was measured, the weight average molecular weight in terms of polystyrene was 32,000.

(Synthesis of polyhydroxyamide resins PHA-1B to PHA-3B)
Polyhydroxyamide resins PHA-1B to PHA-3B were synthesized in the same manner as the synthesis of the polyhydroxyamide resin PHA-1A with the formulation shown in Table 1. In addition, all the solvents used NMP, and it synthesize | combined by melt | dissolving in the quantity ratio which makes the density | concentration of a monomer 20% similarly to the case of PHA-1A. Moreover, the addition amount of pyridine was added so that it might become the amount ratio of 2.5 times mole of a dicarboxylic acid chloride monomer. The weight average molecular weight measured by GPC of the obtained precursor was also shown in Table 1.

(Synthesis of polyamide resin PA-1A)
292.9 parts by weight of the polyhydroxyamide resin PHA-1A was dissolved in 1172 parts by weight of dry THF, 33.4 parts (0.33 mol) of TEA was added, and then THF was dried at −15 ° C. at −15 ° C. 168.8 What melt | dissolved 42.2 weight part (0.3 mol) of BC in the weight part was dripped over 15 minutes. After completion of the dropwise addition, the temperature was returned to room temperature and stirred at room temperature for 8 hours. Thereafter, the reaction solution was dropped into a large amount of ion-exchanged water and re-precipitated, and the precipitate was collected and dried to obtain 313 parts by weight of polyamide resin PA-1A.

(Synthesis of polyamide resins PA-2A to PA-3A)
Polyamide resins PA-2A to PA-3A were synthesized in the same manner as the synthesis of the polyamide resin PA-1A with the formulation shown in Table 2. In addition, the solvent shown in Table 2 was used, and the synthesis was performed by dissolving in a quantitative ratio such that the concentration of the raw material was 20%, as in the case of PA-1A. Table 2 also shows the type and amount of the amine compound of the catalyst.

(Adjustment of resin composition R-1A)
100 parts by weight of the polyamide resin PA-1A and 1 part by weight of TC-I were put into 236 parts by weight of NMP and stirred for about 5 hours using a magnetic stirrer under light shielding to prepare a pale yellow transparent resin composition R-1A. 336 parts by weight of solution were obtained.

(Adjustment of resin compositions R-1C to R-3A)
In the same manner as the adjustment of the resin composition R-1A, the resin compositions R-1C to R-3A were adjusted by the formulation shown in Table 3. In addition, all the solvents used NMP and mix | blended so that the density | concentration of a composition might be 30% similarly to the case of R-1A. A uniform solution was obtained for all formulations.

(Characteristic evaluation of cured product of polyhydroxyamide resin PHA-1A)
30 parts by weight of polyhydroxyamide resin PHA-1A was dissolved in 70 parts by weight of NMP. The obtained solution was applied on a silicon substrate by a spin coating method and heated at 350 ° C. for 1 hour to obtain a film having a thickness of about 3 μm. When the refractive index of this film at 1300 nm light was measured with a prism coupler manufactured by Metricon, the refractive index was 1.520. Next, this sample was immersed in a 2% aqueous hydrofluoric acid solution, peeled off from the silicon substrate, washed with water, and dried to obtain a single film. The obtained film was a colorless and transparent uniform film. With respect to this single film, a 5% weight loss temperature (T-5%) in nitrogen was measured at a heating rate of 10 ° C./min using a TG / DTA measuring machine, and it was 525 ° C.

(Characteristic evaluation of cured products of polyhydroxyamide resins PHA-1B to PHA-3B)
The results of producing a film by using the polyhydroxyamide resin shown in Table 4 and performing the same evaluation in the same manner as in the case of the PHA-1A are shown together in Table 4.

(Characteristic evaluation of cured products of resin compositions R-1A to R-3A)
The results of producing a film using the resin composition solution shown in Table 5 and performing the same evaluation in the same manner as in the case of PHA-1A are shown in Table 5. All operations were performed under light shielding. All of the blending results were inferior to those using a polyhydroxyamide resin in terms of refractive index, colorless transparency, and heat resistance.

(Example 1)
The polyhydroxyamide resin PHA-1B is made into an NMP solution having a concentration of 30% by the same method as described above, applied onto a silicon substrate by spin coating, and heated to 350 ° C. for 1 hour to form a film. did. Next, the resin composition R-1A was spin-coated on the lower clad layer, and prebaked on a hot plate at 100 ° C. for 4 minutes. Next, a photomask (Ti) for pattern formation was placed, irradiated with ultraviolet rays using an ultra-high pressure mercury lamp, and then subjected to post-exposure baking for about 5 minutes on a 120 ° C. hot plate. The obtained sample was developed using an alkaline developer (TMAH: tetramethylammonium hydroxide aqueous solution, concentration 2.38%), and then cured at a maximum temperature of 350 ° C. for 1 hour. As a result, a pattern of a core layer of a linear waveguide having a line width of 6 μm was obtained. On top of that, polyhydroxyamide resin PHA-1B was formed into a film by the same method as that for the lower clad layer to form an upper clad layer. Finally, both ends of the optical waveguide were cut off with a dicing saw to form light incident / exit end faces. Thus, a buried single mode optical waveguide was obtained on the silicon substrate.

  The light propagation loss of the buried single-mode optical waveguide obtained above was measured by a cutback method, and found to be 0.2 dB / cm at a wavelength of 1.3 μm and 0.3 dB / cm at 1.55 μm. Further, the polarization dependence of the light propagation loss was 0.5 dB / cm or less regardless of whether the wavelength was 1.3 μm or 1.55 μm. Further, the light propagation loss of this optical waveguide did not change for more than one month even under the condition of 75 ° C./90% relative humidity.

(Examples 2-3)
In the same manner as in Example 1, each raw material shown in Table 6 was used for the core layer and the cladding layer to create an optical waveguide, and the results of the same evaluation as in Example 1 were shown in Table 6. Indicated. It can be seen that in all systems, optical waveguides having excellent optical performance with small optical propagation loss are obtained.

(Comparative Examples 1-3)
In the same manner as in Example 1, each material shown in Table 7 was used for the core layer and the clad layer, and an optical waveguide was created. However, in the combination of Comparative Examples 1 and 3, when developing the core layer with an alkaline developer, a clean pattern was not obtained, and the evaluation could not be proceeded. This is because the comparative example 1 has too little photoacid generator, so the solubility of the light irradiated part is insufficient, and in comparative example 3, the hydroxyl group of the polyhydroxyamide resin is insufficiently protected, so This is considered to be because of dissolution. Comparative Example 2 was evaluated because a pattern was obtained, but there was a problem with a large optical loss value. This is thought to have had an adverse effect on light loss due to the large amount of photoacid generator added.

  According to the present invention, a high-performance optical waveguide can be produced without using an expensive dry etching apparatus according to the conventional method, and it can be applied to an optical waveguide having a large area pattern. Widely used in the field of optical devices.

Explanatory drawing of the patterning method of the optical waveguide using the resin composition of this invention Explanatory drawing of the manufacture example of the embedded optical waveguide using the resin composition of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Resin layer 3 Photomask 4 Exposure machine 5 Silicon wafer 6 Lower clad layer 7 Resin layer (core layer)
8 Upper cladding layer

Claims (2)

A core layer formed using a photosensitive resin composition containing 0.001 to 5 parts by weight of a photoacid generator with respect to 100 parts by weight of a polyamide resin having a repeating unit represented by the general formula (1) and / or Or an optical waveguide having a cladding layer.

(In the formula (1), X and Y each represents an organic group, Z is selected from an organic group having 10 or less carbon atoms and hydrogen, and the proportion of the organic group having 10 or less carbon atoms is 10% or more. And n is an integer of 5 to 10,000.)   A step of forming a resin layer using a photosensitive resin composition containing 0.001 to 5 parts by weight of a photoacid generator with respect to 100 parts by weight of a polyamide resin having a repeating unit represented by the general formula (1), Production of optical waveguide including a step of forming a photomask layer on the resin layer and patterning the optical waveguide by light irradiation, a step of removing the patterned resin layer with a developer, and a step of heat curing the resin layer Method.

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