JP2009198959A - Optical material, optical waveguide, optical component, and optoelectric hybrid substrate - Google Patents

Abstract

で表される重合性エポキシ化合物（Ｉ）を、１０質量％〜９０質量％含み、さらに光重合開始剤を、０．０５〜５ｐｈｒ含む混合物からなるものである。
【選択図】なしAn optical material, an optical waveguide, an optical component, and an optical material, which solves the incompleteness of the core shape resulting from the slow curing rate due to ionic polymerization of epoxy resin for optical waveguide An opto-electric hybrid board is provided.
[Means for Solving the Problems]
[Chemical 1]

The polymerizable epoxy compound (I) represented by the formula (1) is a mixture containing 10% by mass to 90% by mass and further containing 0.05 to 5 phr of a photopolymerization initiator.
[Selection figure] None

Description

  The present invention relates to a polymer material for an optical waveguide used for an opto-electric hybrid board and an optical component, particularly an optical material made of an epoxy for an optical waveguide, and in particular, to improve the heat resistance of the epoxy material for an optical waveguide and to form a waveguide. The present invention relates to an optical material, an optical waveguide, an optical component, and an opto-electric hybrid board that have excellent heat resistance, low light loss, high heat resistance, and excellent heat resistance during a solder reflow process.

  With the spread of information and communication services, large-capacity and high-speed data transmission in information processing devices has been demanded. Although the performance of information processing using electrical signals is improved, problems such as crosstalk, electromagnetic radiation, band limitation, and loss due to higher frequencies appear as the signal speed increases. A transmission distance of about 10 m at a transmission speed of 1 GHz is considered to be about 1 m at a transmission distance of 10 GHz, and it is expected that speeding up with an electric signal is difficult.

  Therefore, opticalization of signals has been studied, and an attempt has been made for optical interconnection in which information transmission is performed by providing optical wiring between information processing devices, between boards (printed boards), and between chips.

  In the optical interconnection between boards and chips, it is expected that an opto-electric hybrid board using both light and electricity as a signal medium is used by providing an optical / electrical signal conversion unit.

  There are two main types of opto-electric hybrid boards.

  One is a method in which optical wiring and electrical wiring are mixed in the substrate. In this method, a waveguide is formed on the surface of a substrate provided with a through-hole through which light passes, and the light from the waveguide is incident on the through-hole by changing the optical path by 90 °. In order to allow light from the hole to enter the waveguide, the waveguide has a structure in which a mirror inclined by 45 ° with respect to the optical axis of the waveguide is disposed. An electronic device and an electronic circuit such as an LD (laser diode), a PD (photodiode), and an LSI are arranged in the through hole portion on the back side of the substrate opposite to the waveguide.

  As an example, glass epoxy is used for the substrate, a through hole is provided in the substrate, epoxy resin is injected into the substrate, a waveguide is formed across the through hole, a 45 ° mirror is formed in the through hole portion, and light is emitted. There is an electrical mixed substrate manufactured (Endo et al., IEICE, 2002, Autumn, C-3-139).

  As another opto-electric hybrid method, a structure in which electronic devices such as LD, PD, LSI, and electronic circuits are arranged on a substrate and a waveguide sheet or an optical fiber prepared in advance is attached to the upper part has been studied.

  In these systems, a solder reflow process is required when an LD, PD, electronic device, or electronic circuit is placed on a substrate.

  A waveguide used for opto-electric hybrid mounting is presumed to be a multi-mode waveguide from the viewpoint of easy connection. In addition, an opto-electric hybrid board using a VCSEL (Vertical 1 Cavity Surface-Emitting Laser) having a wavelength of 850 nm most promising as a light source in the opto-electric hybrid board has been studied.

  As a requirement for an optical waveguide used for an opto-electric hybrid board, a multi-mode waveguide can be formed, and in particular, low optical loss at 850 nm and low cost can be mentioned.

  The optical loss factors of optical waveguides include loss inherent to the material due to the molecular structure due to electronic transition absorption of the material itself, optical absorption due to external substances such as impurities, and non-uniformity in the optical waveguide material due to impurity contamination There is a scattering loss due to the incompleteness of the core structure of the manufactured optical waveguide.

  As the optical waveguide material, it is necessary to use a material that absorbs less light and uniformly disperses at the molecular level, and it is important to use a material and a process that can enhance the integrity of the core structure for manufacturing the optical waveguide.

  If the boundary between the core and the cladding is not smooth and there are irregularities, the light beam propagating in the core is bent at the irregularities and mode-converted, or partially exceeds the critical angle of total reflection. The light radiates to the layer and leaks outside. In the case of a waveguide with a long distance, if there are slight irregularities, a coupling loss between modes due to scattering loss and mode conversion occurs, which causes an increase in optical loss and a limitation on the transmission band.

  Also, in producing an opto-electric hybrid mounting board, LD, PD, electronic device, etc. are mounted with solder bumps together with the optical waveguide, so that the optical waveguide is solder reflow conditions (for example, 250 ° C./10 for gold / tin eutectic solder). It is essential to have heat resistance against (second x 3 times).

  The optical waveguide material used for the opto-electric hybrid mounting substrate is required not to cause structural defects such as cracks and peeling at high temperatures of solder reflow, and not to increase optical loss due to coloring.

  Quartz-based materials and organic polymer materials are widely studied as materials for optical waveguides. Quartz-based materials have very low light loss and excellent heat resistance and reliability, and are used in backbone communication devices together with quartz-based optical fibers.

  However, since the manufacturing process of the quartz optical waveguide is manufactured by lithography technique and dry reactive ion etching (RIE), the process is complicated and expensive. Furthermore, the flame deposition method for depositing a material on a substrate is a high-temperature process, and an opto-electric hybrid substrate has a problem of deterioration of electrical components and substrates mounted on the same substrate.

  The optical polymer waveguide manufacturing method is as follows: (1) Stamper method (Electronic material November 2002 issue P27-P30), (2) Direct exposure method (Sato, Nibo: 56th year of the Institute of Electronics, Information and Communication Engineers) A collection of conference papers (Science Univ.), No. 997 (1981)), (3) reactive ion etching (RIE) method, and (4) photobleaching method are known.

  Any of these production methods is a low-temperature process, and can be produced under mild conditions without damage to electric parts and the like.

  The stamper method (1) is a method that can be produced in a large amount at a low cost. However, there is a problem that imperfection of the core structure occurs due to deterioration of the mold due to repeated use.

  The reactive ion etching (3) needs to be performed together with the lithography process, and the process is complicated and the cost is high.

  The photobleaching method (4) is a simple method, but it is difficult to control the refractive index change in the film depth direction when a multimode waveguide having a large core diameter is produced.

  Therefore, the method for producing a polymer optical waveguide is considered to be most advantageous from the viewpoint that the direct exposure method of (2) is repetitive production reliability and simple and low cost.

  The outline of the photosensitive / developing process is as follows.

  (A) A lower clad material is applied on a substrate by a spin coat method or a dip method and cured, and then a photosensitive core material is applied.

  (B) After exposing and curing the core material through a photomask, the unexposed portion is dissolved and removed with a developer.

  (C) An upper cladding layer is applied thereon and then cured to obtain an optical waveguide.

  As organic polymer materials for optical waveguides, polyimide-based, epoxy-based, acrylic-based materials, copolymers and mixtures thereof have been studied.

  The polyimide system has excellent transparency particularly in a wavelength region of 1300 nm in fluorinated polyimide, has a heat resistance of 350 ° C. or more, and also has solder reflow resistance.

  However, since the polyimide precursor varnish contains a large amount of an organic solvent, it is very difficult to form a core having a film thickness of 50 μm or more. Since a dry etching apparatus is used, the cost is high and it is not suitable for mass production.

  Acrylic materials have good transparency in the near-infrared region and visible light region of 850 nm, can be thickened (50 μm or more), and can form a core by a low-cost direct exposure method.

  Usually, acrylic materials are cured by radical polymerization. Since radical polymerization has a high polymerization rate and has sufficient curability to maintain the core shape at the development stage after exposure, a rectangular core can be formed.

  However, the heat resistance of acrylic materials is as low as about 100 ° C., and when these are used in the optical waveguide of the opto-electric hybrid board, the solder reflow resistance is not sufficient.

  Epoxy materials have good transparency in the near-infrared region and visible light region of 850 nm, are relatively high in heat resistance of about 200 ° C., can be core-formed by direct exposure, and are promising as optical waveguide materials. It is.

  Polymerization of the epoxy material proceeds by ionic polymerization of a cation or an anion, and is not inhibited by oxygen unlike radical polymerization. Even an epoxy material having relatively high heat resistance is not sufficient for the solder reflow temperature of the gold / tin eutectic solder, and higher heat resistance needs to be imparted.

  As a method of imparting higher heat resistance, there is a method of dispersing a metal oxide in a polymer material. A heat-resistant polymer in which a metal alkoxide is condensed by a sol-gel method to form a metal oxide network and mixed in the polymer has been studied. The heat resistance of the metal oxide, which is a heat-resistant polymer inorganic substance, can impart heat resistance to the organic base polymer.

  One of these organic / inorganic composite materials is an organic / inorganic hybrid method, which uses 3- (trimethoxysilyl) propyl methacrylate, zirconium alkoxide, and methacrylic acid to perform hydrolysis by a sol-gel method, and an acrylic-based method. There is a method for obtaining an organic / inorganic hybrid material (M. He, X.-C. Yuan, J. Bu, and B. H. Ong, Appl. Opt., 302 (2007)).

  In this material, the waveguide is patterned by reacting with a methacryl group by a direct exposure method.

  Patent Document 1 discloses an organic-inorganic hybrid material in which silica particles are dispersed in a nano-size in an epoxy compound, has high solder heat resistance by hybridization with an inorganic substance, and uses a metal-organic catalyst to perform a sol-gel reaction. Therefore, there has been proposed an optical waveguide material in which deterioration of electrical wiring due to acid or base is reduced.

  In addition, there are Patent Documents 2 and 3 as prior documents.

JP 2005-250287 A JP 2007-128028 A JP 2006-38962 A

  By the way, the polymerization of the epoxy material proceeds by ionic polymerization of cationic or anionic polymerization. Ion polymerization is not inhibited by oxygen, but the reaction rate is slow compared to radical polymerization, and when forming a core by direct exposure, it is difficult to obtain sufficient curability at the development stage, and the shape collapses due to the development process. And swelling due to a developing solution occurs, and there is a problem that it is difficult to stably obtain a rectangular shape.

  When the boundary between the core and clad of the optical waveguide is not smooth and imperfect, the light beam propagating through the core is bent at the uneven part, and the light beam is mode-converted or partially exceeds the critical angle of total reflection. Thus, the light is radiated to the cladding layer and leaked to the outside, and the optical loss increases.

  In addition, it is important to use a material and a process that can enhance the integrity of the core structure in manufacturing the optical waveguide. Furthermore, ordinary epoxy materials do not have sufficient solder heat resistance, and higher heat resistance is required to make a waveguide for opto-electric hybrid mounting.

  The present invention has been made in order to solve the above-described problems. A method for increasing the curing speed of an epoxy-based optical waveguide material and enhancing the integrity of a core shape, and imparting solder heat resistance to the material. A method is provided.

  That is, an object of the present invention is to solve the incompleteness of the core shape resulting from the slow curing rate due to the ionic polymerization of the epoxy resin for optical waveguides, and to provide an optical material and a light guide having solder heat resistance. The object is to provide a waveguide, an optical component, and an opto-electric hybrid board.

  In order to achieve the above-mentioned object, the invention of claim 1 includes the following chemical compounds as components:

An optical material comprising a mixture containing 10% to 90% by weight of the polymerizable epoxy compound (I) represented by the formula (1) and further containing 0.05 to 5 phr of a photopolymerization initiator.

The invention of claim 2 comprises an epoxy mixture containing 10% to 90% by mass of the polymerizable compound (I) and 0 to 90% by mass of the polymerizable compound having an epoxy group, and a total amount of 100 parts by weight of the epoxy mixture. against, the integer .R ¹ polymerizable organosilicate material _{^{10~70phr SiR 1 n (OR 2)}} 4-n (n = 0~2 is a hydrocarbon group containing an epoxy group, R ² is coal water number 1 5), a photopolymerization initiator was mixed in an amount of 0.05 to 5 phr to a resin composition obtained by heating a mixture containing water and an organometallic compound catalyst at 80 to 180 ° C. for 1 to 5 hours. Is an optical material characterized by

  The invention according to claim 3 is the optical material according to claim 2, wherein the polymerizable organosilicate material is 3-glycidoxypropyltrimethoxysilane.

  The invention according to claim 4 is the optical material according to claim 2 or 3, wherein the organometallic compound catalyst is an organotin compound.

  Invention of Claim 5 apply | coats the optical material in any one of Claims 1-4 on the lower clad layer formed on the board | substrate, hardens the exposure part used as a core by exposure of an ultraviolet-ray, and is unexposed An optical waveguide is characterized in that an upper clad layer is formed after forming a core by removing a portion with a developing solution.

  The invention according to claim 6 is an optical component manufactured using the optical material according to claims 1 to 4.

  A seventh aspect of the present invention is an opto-electric hybrid board manufactured using the optical material according to the first to fourth aspects.

  The optical waveguide material of the present invention makes it possible to produce an optical waveguide core having a good shape by a simple method at a low cost. In addition, the optical waveguide material of the present invention has high heat resistance and can have solder reflow heat resistance. Therefore, the present invention is suitable for optical waveguides for opto-electric hybrid boards, waveguides for optical devices, and optical device components.

  A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

  The optical waveguide epoxy material of the present invention contains an epoxy compound (I) of bisphenol S-type diglycidyl ether represented by Chemical Formula 2 as an essential component.

  Since this bisphenol S-type diglycidyl ether compound has a highly polar sulfonyl group, it is a reaction by cationic polymerization compared to bisphenol A-type diglycidyl ether and bisphenol F-type diglycidyl ether, which are general-purpose epoxy materials. The speed is fast.

  By using this bisphenol S-type diglycidyl ether as a constituent component and using a material mixed with a photoacid generator, a curing reaction occurs immediately upon exposure to ultraviolet rays during the production of the optical waveguide, and the unexposed portion by the developer after exposure At the stage of removal, the core shape does not collapse due to insufficient curing and the swelling due to the developer does not occur, and a rectangular core shape with high integrity can be obtained. By obtaining a rectangular core shape with high integrity, it is possible to obtain a waveguide in which an increase in light loss due to scattering due to imperfect structure is suppressed.

  In the cured product of bisphenol S-type diglycidyl ether, the linear expansion coefficient of the cured product of bisphenol S-type diglycidyl ether is bisphenol due to the interaction between sulfonyl groups and the restriction of molecular motion based on the hydrogen bond between the sulfonyl group and the hydroxyl group. Smaller than A type and bisphenol F type (Hasegawa, Journal of Adhesion Society of Japan, 273, 26 (1990)). Therefore, it has the feature that defects such as cracks can be suppressed by suppressing the linear expansion of the optical waveguide and reducing the difference in linear expansion coefficient from the substrate.

  When the content of bisphenol S-type diglycidyl ether is small, the effect of increasing the curing speed of the material is small, and when it is excessively large, the transparency is lowered, so mixing with other epoxy compounds The ratio is 10 to 90% by mass, preferably 30 to 70% by mass, based on the content of bisphenol S-type diglycidyl ether.

  Furthermore, since bisphenol S-type diglycidyl ether is a solid material at room temperature, the content of bisphenol S-type diglycidyl ether is preferably 30 to 70% by mass in order to obtain a viscosity with good coatability. .

  Since bisphenol S-type diglycidyl ether is a material having a high refractive index due to the polarity of the sulfonyl group, the necessary refractive index difference between the core and the clad is provided by changing the mixing ratio with the low refractive index epoxy group-containing compound. Is possible. Bisphenol S-type diglycidyl ether can also be used as an additive for enhancing the integrity of the core shape of the optical waveguide epoxy material.

  The epoxy compound to be mixed with bisphenol S-type diglycidyl ether is not particularly limited, but aliphatic epoxy, alicyclic epoxy, fluorinated aliphatic epoxy, fluorinated bisphenol-type epoxy, hydrogenated bisphenol A-type diglycidyl ether, hydrogenated Bisphenol F type glycidyl ether, 1,4-cyclohexene A diglycidyl ether type epoxy, bicyclohexyl diglycidyl ether type epoxy, 3,4-epoxycyclohexenyl-3 ′, 4′-epoxycyclohexene carboxylate, 1,2: There are glycidyl ester type epoxies obtained by reaction of polybasic acids such as 8,9 diepoxy limonene, phenol novolac type epoxies, phthalic acid and dimer acid and epichlorohydrin. These may be used alone or in combination of two or more in order to adjust the required refractive index.

  Specific examples of photoacid generators that are photopolymerization initiators include CI-5102, CI 2855, Adekaoptomer SP-150, Adekaoptomer SP-170, Sun-Aid SI-110L, IRGACURE 261, and the like. The photoacid generator can be blended alone or in combination of two or more as required.

  Moreover, not only a photoacid generator but also a thermal acid generator can be used in combination.

  Examples of the thermal acid generator include Adeka Opton CP-66, Adeka Opton CP-77, Sun-Aid SI-100L, Sun-Aid SI-145, Sun-Aid SI-150, Sun-Aid SI-160, CI-2624, and CI-2639.

  Examples of the photo / thermal acid generator include CI-2855, Sun-Aid SI-60L, Sun-Aid SI-80L, and Sun-Aid SI-100L. If the amount of the photoacid generator is too small, the curing of the optical waveguide material is delayed, and imperfections are likely to occur in the core shape. If the photoacid generator is too much, it has strong light absorption in the ultraviolet region, so that absorption of light reaches a wavelength of light such as 850 nm propagating in the optical waveguide, and the light loss increases.

  The content of the photoacid generator is preferably 0.05 to 5.0 phr with respect to 100 parts by weight of the total amount of the epoxy mixture of the polymerizable compound (I) and the polymerizable compound having an epoxy group. When the thermal acid generator is used in combination, the thermal acid generator may be used in any amount as long as the transparency of the optical waveguide is not impaired.

  The chemical structure of bisphenol S-type diglycidyl ether is highly rigid and has a structure that imparts heat resistance compared to bisphenol A, F-type diglycidyl ether, and the like. By using this material as an organic-inorganic hybrid material, a material having higher heat resistance can be obtained.

  As a parameter that affects the heat resistance of the organic material, there is a glass transition temperature (Tg). Below Tg, the molecular motion of the main chain of the polymer material is frozen into a glass state, whereas when it is above Tg, the elastic modulus decreases rapidly, the diffusion rate of the substance increases, and thermal decomposition begins. Various physical properties are drastically lowered, such as various reaction rates are increased.

  In the case of organic materials, except for some organic materials such as polyimide and polybenzoxazole, Tg is 300 ° C. or lower, and therefore, organic materials having solder reflow resistance have been limited.

  However, in Patent Document 1, an organic-inorganic hybrid is formed by mixing a polymerizable organic material with 3-glycidoxypropyltrimethoxysilane and heating to color the optical material at a high temperature (300 ° C.). It has been found that a rapid decrease in elastic modulus is prevented, and both low transmission loss and reflow resistance are achieved.

In this organic / inorganic hybrid material, a silica (SiO ₂ ) component produced by a sol-gel reaction between methoxy groups of 3-glycidoxypropyltrimethoxysilane is uniformly dispersed in a resin with a particle size of about 5 nm, and thermosetting is performed. By selecting a functional resin, a heat-resistant optical material having excellent transparency with small scattering loss and absorption loss in a wavelength range from visible light to near infrared has been obtained. In addition, by using an organometallic catalyst instead of an acid or base remaining in the material as a catalyst during the sol-gel reaction, the reliability of the electrical wiring mounted along with the waveguide and the waveguide is greatly improved. Can do.

  Also in the present invention, organic-inorganic hybridization is possible, and heat resistance can be improved.

In the above, the present invention relates to 10 to 90% by mass of bisphenol S-type diglycidyl ether, 0 to 90% by mass of a polymerizable compound having an epoxy group, and 10 to 70 phr (% by mass) of a polymerizable organosilicate material SiR ¹ _n. (OR ² ) _4-n (n = 0 to 2; R ¹ is a hydrocarbon group containing an epoxy group, R ² is a hydrocarbon group having 1 to 5 carbon atoms), water, and an organometallic compound catalyst An organic-inorganic hybrid material can be obtained by heating the mixture at 80 to 180 ° C. for 1 to 5 hours and mixing a photopolymerization initiator with a resin composition obtained by performing a sol-gel reaction.

  As the polymerizable organosilicate agent, 3-glycidoxypropyltrimethoxysilane having a methoxy group in which the sol-gel reaction proceeds rapidly is preferable.

  The temperature at which these mixtures are heated is 80 to 190 ° C. in order to increase the reaction rate, to prevent the material from being difficult to apply due to high viscosity and to prevent solidification of the material during heating due to gelation. Is preferred. More preferably, it is 120-160 degreeC. Further, in order to prevent the viscosity from being excessively increased and the sol-gel reaction is appropriately advanced during the heating time, it is preferably 1 to 5 hours. When the heating time is short, sol-gel reaction due to unreacted sites often occurs even after the material is adjusted. Therefore, the material becomes non-uniform and bubbles are generated due to water or alcohol desorbed by the reaction.

  The organic-inorganic hybrid sol-gel reaction can be performed by adding water and an organometallic compound as a catalyst. When an organic metal is used, the reaction proceeds in a neutral state, so that no acid or base remains in the material after the reaction is completed. Therefore, organic / inorganic composite materials that have undergone a sol-gel reaction using organometallics are significantly more effective in waveguides and electrical devices than when acids and bases are used in the waveguides mounted on the substrate along with the electrical wiring. Wiring reliability can be improved.

  As the organic metal, for example, an organic tin compound can be used.

  Examples of the organic tin compound include tin dibutyl dilaurate, tin dioctyl dilaurate, dibutyl tin diacetate, tin (II) octoate, dibutyl tin diacylate, bis (acetoxydibutyltin) oxide, bis (lauroxydibutyltin) oxide, Examples include dibutyltin bisacetylacetonate, dibutyltin bismaleic acid monobutyl ester, and dioctyl bismaleic acid monobutyl ester.

  Other examples of organometallic catalysts include ferric octoate, lead octoate, lead laurate, cobalt naphthenate, diisopropoxy titanium bis (acetylacetonate), titanium tetra (acetylacetonate), dioctanoxy Examples include titanium dioctanoate and diisopropoxy titanium bis (ethyl acetoacetate). These may be used alone or in combination of two or more.

  An optical waveguide material containing bisphenol S-type diglycidyl ether as a constituent can be mixed with a liquid compound having an epoxy group, or formed into an organic-inorganic hybrid to form a liquid varnish. Application processes such as coating and dip coating can be performed. Moreover, a general purpose organic solvent can also be used for viscosity adjustment.

  A glass epoxy substrate, a Si substrate, a quartz substrate, a glass substrate, a polyimide substrate, other resin substrates, or the like can be used as a substrate for forming the optical waveguide.

  Ultraviolet exposure can be performed using a general ultraviolet exposure machine that emits i-line (wavelength 365 nm).

  A general-purpose organic solvent can be used as the developer used after the exposure. As a developer, MEK (methyl ethyl ketone), THF (tetrahydrofuran), MIBK (methyl isobutyl ketone), acetone, ethyl acetate, benzene, toluene, xylene, NMP (N-methyl-2-pyrrolidone), tetraethylammonium hydroxide aqueous solution, etc. Can be used. These may be used alone or in combination or with different concentrations. The developer can be used in the same manner when an organic-inorganic hybrid material is used.

  In the optical material of the present invention, a conventionally used flame retardant or antioxidant can be blended and used to such an extent that the transparency is not impaired.

EXAMPLES Next, although an Example demonstrates this invention concretely, the scope of the present invention is not limited to these Examples.
(1) Sample material Sample materials used in Examples and Comparative Examples are shown. Hereinafter, these are indicated by abbreviations.

EXA;
Epoxy resin = bisphenol S type diglycidyl ether (Dainippon Ink Chemical Co., Ltd., trade name = EPICLON EXA-1514, abbreviation EXA),
YDF;
Epoxy resin = bisphenol F type diglycidyl ether (manufactured by Toto Kasei Co., Ltd., trade name = YDF-8170C, epoxy equivalent 160, abbreviation YDF),
8125;
Epoxy resin = bisphenol A type diglycidyl ether (manufactured by Toto Kasei Co., Ltd., trade name = YD-8125, epoxy equivalent 175, abbreviation 8125),
2021;
Epoxy resin = 3,4-epoxycyclohexenyl-3 ′, 4′-epoxycyclohexene carboxylate (manufactured by Daicel Corporation, trade name = Celoxide 2021 P, abbreviation 2021),
GTMS;
Organosilicate compound = 3-glycidoxypropyl-trimethoxysilane (manufactured by Chisso Corporation, trade name = S510, abbreviation GTMS),
Dibutyltin dilaurate (manufactured by Wako Pure Chemical Industries, Ltd.),
170;
Photoacid generator = Adekaoptomer SP170 (Asahi Denka Co., Ltd., abbreviation 170)
Example 1
An optical waveguide core material containing 50% by mass of 8125, 30% by mass of bisphenol S-type diglycidyl ether EXA, 20% by mass of 2021, and 1 phr of SP170 was prepared.

  As shown in FIG. 1A, a lower clad layer 2 made of an epoxy material having a refractive index lower than that of a core material is provided on a substrate 1, and light is applied to the clad layer 2 by spin coating as shown in FIG. A core material 2 is applied by applying a core material for a waveguide, and the core layer 2 is exposed to ultraviolet rays 4 through a photomask 5 in which an opening 5a serving as a core portion is formed as shown in FIG. . After exposure, the material of the unexposed portion is removed with an organic solvent to produce an optical waveguide core 6 as shown in FIG. 1 (e), and then an upper cladding layer 7 is provided as shown in FIG. 1 (f), An embedded optical waveguide 10 was obtained. The obtained waveguide 10 was post-baked at 180 ° C. for 1 hour.

  The shape of the core 6 after the development was a good rectangular shape with no collapse during development or swelling due to the organic solvent, and was a smooth wall surface.

  The transmission loss of this optical waveguide was measured.

  Both end faces of the optical waveguide were cut out with a dicing saw with a diamond blade. Light having a wavelength of 850 nm is incident on the optical waveguide from a GI fiber having a diameter of 50 μm from one end face of the optical waveguide, and light emitted from the optical waveguide is received by a fiber having a ferrule having a diameter of 200 μm on the other end face. The amount of light was measured by making it enter. The amount of light was measured while cutting the length of the optical waveguide with a dicing saw, and the transmission loss per unit centimeter was determined.

  In the case of this optical waveguide, the transmission loss was a good value of 0.12 dB / cm.

Example 2
An optical waveguide core material containing 10% by mass of YDF, 70% by mass of EXA, 20% by mass of 2021, and 1 phr of SP170 was prepared by dissolving in an organic solvent.

  This material was applied onto the clad layer by spin coating and exposed to ultraviolet rays through a mask. After the exposure, the material in the unexposed area was removed with an organic solvent to obtain an optical waveguide core. The obtained core shape was rectangular and was a smooth wall surface.

  An upper clad layer was provided on the core to form a buried optical waveguide, and post-baking was performed at 170 ° C. for 1 hour.

  When the optical loss of this waveguide was measured, it was a good value of 0.13 dB / cm at a wavelength of 850 nm.

Example 3
An organic-inorganic hybrid material containing bisphenol S-type diglycidyl ether as a constituent material was prepared and evaluated. A solution containing 35% by mass of EXA, 15% by mass of 2021, and 50% by mass of GTMS was stirred for 30 minutes and allowed to stand for 16 hours. To this solution, dibutyltin dilaurate, water and a catalyst were added and heated at 150 ° C. for 4 hours. During heating, water and methanol generated by condensation were discharged out of the system. 1 phr of SP170 was added to the solution after heating, and the viscosity was adjusted by adding an organic solvent to obtain an optical waveguide core material.

  This material was spin-coated on the clad layer and exposed to ultraviolet rays through a photomask. After the exposure, the material in the unexposed area was removed with an organic solvent to produce an optical waveguide core. The obtained core shape was rectangular and was a smooth wall surface.

  An upper cladding layer was provided, and post-baking was performed at 200 ° C. for 1 hour to obtain a buried optical waveguide.

  The optical loss of this optical waveguide was 0.10 dB / cm at a wavelength of 850 nm.

Example 4
A solution containing 25% by mass of 8125, 15% by mass of EXA, 10% by mass of 2021, and 50% by mass of GTMS was stirred for 30 minutes and allowed to stand for 16 hours. To this solution, a catalyst of dibutyltin dilaurate and water was added and heated at 150 ° C. for 4 hours. During heating, water and methanol generated by condensation were discharged out of the system. 1 phr of SP170 was added to the solution after heating, and the viscosity was adjusted by adding an organic solvent to obtain an optical waveguide core material.

  This material was spin-coated on the clad layer and exposed to ultraviolet rays through a photomask. After the exposure, the material in the unexposed area was removed with an organic solvent to produce an optical waveguide core. The obtained core shape was rectangular and was a smooth wall surface.

  An upper cladding layer was provided, and post-baking was performed at 200 ° C. for 1 hour to obtain a buried optical waveguide.

  The optical loss of this optical waveguide was 0.09 dB / cm at a wavelength of 850 nm.

Example 5
A solder reflow test was performed on the optical waveguide core materials of Examples 3 and 4. In the solder reflow test, an optical waveguide core material was used to make a fiber, and evaluation was performed by measuring optical loss in the form of a fiber.

  The produced fiber was heated by passing it through a solder reflow furnace three times in air. A temperature profile of a typical solder reflow test is shown in FIG.

  The temperature profile is maintained at 150 to 200 ° C. for about 150 to 160 seconds and at a peak temperature of 250 ° C. for about 20 to 30 seconds.

  The optical loss at a wavelength of 850 nm of the fiber after passing through the solder reflow furnace three times was 0.12 dB / cm and 0.10 dB / cm for the optical waveguide core materials of Example 3 and Example 4, respectively. . The increase in optical loss of the fiber after the test was about 0.01 to 0.02 dB / cm, and it was an optical waveguide material having good solder reflow heat resistance.

It is a figure which shows the process until producing an optical waveguide core by the direct exposure method using the optical waveguide material of this invention. It is a figure which shows a solder reflow furnace temperature profile when performing a solder reflow test with respect to the optical waveguide material of this invention.

Explanation of symbols

1 Substrate 2 Lower cladding layer 6 Optical waveguide core 7 Upper cladding layer

Claims (7)

The following chemical components

An optical material comprising a mixture containing 10% by mass to 90% by mass of the polymerizable epoxy compound (I) represented by the formula (1) and further containing 0.05 to 5 phr of a photopolymerization initiator. 10 to 70 phr with respect to 100 parts by weight of the epoxy mixture containing 10 to 90% by weight of the polymerizable compound (I) and 0 to 90% by weight of the polymerizable compound having an epoxy group, and 100 parts by weight of the total amount of the epoxy mixture. Polymerizable organosilicate material SiR ¹ _n (OR ² ) _4-n (where n is an integer of 0 to 2. R ¹ is a hydrocarbon group containing an epoxy group, R ² is a hydrocarbon group having 1 to 5 hydrocarbons) and An optical material, wherein a photopolymerization initiator is mixed in an amount of 0.05 to 5 phr to a resin composition obtained by heating a mixture containing water and an organometallic compound catalyst at 80 to 180 ° C. for 1 to 5 hours.   The optical material according to claim 2, wherein the polymerizable organosilicate material is 3-glycidoxypropyltrimethoxysilane.   The optical material according to claim 2 or 3, wherein the organometallic compound catalyst is an organotin compound.   The optical material according to any one of claims 1 to 4 is applied onto a lower clad layer formed on a substrate, an exposed portion serving as a core is cured by exposure to ultraviolet rays, and an unexposed portion is removed with a developer. An optical waveguide characterized by forming an upper clad layer after forming a core.   An optical component manufactured using the optical material according to claim 1.   An opto-electric hybrid board produced using the optical material according to claim 1.

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