JP2009186979A - Method of manufacturing optical waveguide composite substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an optical waveguide composite substrate which has no meandering in a core pattern, which excels in heat resistance, and which by thermal hysteresis causes no separation of an optical waveguide from a silicon substrate nor crack of the silicon substrate. <P>SOLUTION: The method includes: (A) a stage of forming a cladding layer by laminating a lower cladding layer-forming resin film on a substrate through a tacky adhesive layer; (B) a stage of forming a core layer by laminating a core layer-forming resin film on the cladding layer; (C) a stage of forming a core pattern by exposure to light and development; and (D) a stage of forming an upper cladding layer by laminating an upper cladding layer-forming resin film on the core pattern. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an optical waveguide composite substrate, and more particularly to a method for manufacturing an optical waveguide composite substrate in which an optical waveguide is laminated on a substrate such as a silicon substrate via an adhesive layer.

In order to cope with the increase in information capacity accompanying the spread of the Internet and LAN (Local Area Network), not only for communication fields such as trunk lines and access systems, but also for short-distance signal transmission between boards in routers and server devices or within boards. Development of optical interconnection technology using optical signals is in progress. As an optical transmission line in this case, it is desirable to use an optical waveguide that has a higher degree of freedom in wiring and can be densified than an optical fiber. In particular, a polymer material that is excellent in workability and economy is used. The optical waveguide that was used is promising. Specifically, since the polymer optical waveguide is used for optical signal transmission between boards in a router or a server device or in a board, an opto-electric hybrid board coexisting with an electric wiring board has been developed.
By the way, as a method of forming an optical waveguide composite substrate by forming an optical waveguide on a substrate, for example, when using a silicon substrate, a silane coupling agent or the like is applied on the silicon substrate, and a lower portion is formed thereon. There has been proposed a method for manufacturing an optical waveguide composite substrate in which a clad layer, a core layer, and an upper clad layer are applied by a spin coating method or the like, and the core layer is patterned by a method such as etching (see Patent Document 1).
There is also a method in which an optical waveguide is prepared in advance and the optical waveguide is attached to a substrate such as a silicon substrate via an adhesive layer. This method is very simple and highly productive.

JP 2000-351809 A

However, the optical waveguide composite substrate manufactured by applying the optical waveguide forming material onto the silicon substrate by a method such as spin coating as described above has a problem in heat resistance. In particular, recent highly integrated composite substrates may undergo a severe thermal history, and peeling may occur at the interface between the silicon substrate and the lower cladding layer. In addition, when a silane coupling agent or the like is formed in order to improve the adhesion between the lower clad layer and the silicon substrate, the silicon substrate cannot follow the thermal expansion of the optical waveguide. In some cases, the silica film formed on the surface of the silicon substrate was destroyed, causing cracks in the silicon substrate.
Further, in the manufacturing method in which the optical waveguide is manufactured and pasted to the silicon substrate via the adhesive layer, the core pattern of the optical waveguide composite substrate is manufactured in the process of manufacturing the optical waveguide or in the process of pasting the optical waveguide to the substrate. In some cases, meandering is observed, and when a very precise core pattern is required, or when a large-area optical waveguide composite substrate is required, a problem may occur.

Furthermore, when a plurality of optical waveguide composite substrates are cut out from the optical waveguide composite substrate wafer, if the core pattern is meandering, the core is not located at the center of the cut out optical waveguide composite substrate. Such an optical waveguide composite substrate is treated as a defective product depending on the application, and as a result, the yield deteriorates and the production efficiency may decrease.
In view of these problems, the present invention provides an optical waveguide in which the core pattern does not meander, is excellent in heat resistance, and does not cause peeling of the optical waveguide from the silicon substrate or cracking of the silicon substrate due to thermal history. An object of the present invention is to provide a method for manufacturing a composite substrate.

As a result of diligent investigation, the present inventor has found that the above problem can be solved by using a method of laminating a film for forming an optical waveguide on a substrate such as a silicon substrate via an adhesive layer. It was.
That is, the present invention
(1) (A) a step of laminating a resin film for forming a lower clad layer on a substrate via an adhesive layer to form a clad layer, (B) laminating a resin film for forming a core layer thereon Forming a core layer, (C) forming a core pattern by exposure / development, and (D) forming an upper clad layer by laminating a resin film for forming an upper clad layer on the core pattern. Manufacturing method of optical waveguide composite substrate,
(2) The method for producing an optical waveguide composite substrate according to (1) above, wherein the storage elastic modulus at 125 ° C. measured under the following conditions of the adhesive composition constituting the adhesive layer is 10 MPa or less,
Storage elastic modulus measurement conditions: the size of the test piece is 20 mm in length, 4 mm in width, and 80 μm in film thickness, the heating rate is 5 ° C./min, the tensile mode, the vibration frequency is 10 Hz, and the automatic static load is used.
(3) The adhesive composition is mainly composed of at least one adhesive component selected from a compound having two or more epoxy groups in the molecule and a compound having an ethylenically unsaturated group in the molecule. The method for producing an optical waveguide composite substrate according to (2), which is contained as
(4) The adhesive composition comprises (a) a high molecular weight component having a functional group-containing weight average molecular weight of 100,000 or more, (b) an epoxy resin, (c) a phenolic epoxy resin curing agent, (d (2) or (2) containing a photoreactive monomer having a Tg of 250 ° C. or higher, and (e) a photoinitiator that generates a base and a radical upon irradiation with ultraviolet light having a wavelength of 200 to 450 nm. 3) A method for producing an optical waveguide composite substrate according to 3),
(5) (a) The high molecular weight component having a functional group-containing weight average molecular weight of 100,000 or more is a glycidyl group-containing (meth) acrylic copolymer containing 0.5 to 6% by mass of a glycidyl group-containing repeating unit. A method for producing an optical waveguide composite substrate according to (4) above,
(6) (a) 100 parts by mass of component (b) 5 to 250 parts by mass of component, (d) 5 to 100 parts by mass of component, (e) 0.1 to 20 parts by mass of component, (c) The optical waveguide composite substrate as described in (4) or (5) above, wherein the equivalent ratio of the phenolic hydroxyl group per epoxy group of the epoxy resin as the component (b) is in the range of 0.5 to 1.5. And (7) any one of the above (1) to (6), wherein the adhesive layer is formed by laminating an adhesive sheet comprising an adhesive composition and a supporting substrate. A method for producing the optical waveguide composite substrate according to claim 1,
Is to provide.

  According to the present invention, a manufacturing method of an optical waveguide composite substrate in which no meandering is seen in the core pattern, excellent in heat resistance, and the optical history does not cause peeling of the optical waveguide from the silicon substrate or cracking of the silicon substrate. Can be provided.

  The method for producing an optical waveguide composite substrate of the present invention includes (A) a step of laminating a resin film for forming a lower clad layer on a substrate via an adhesive layer, and (B) forming a clad layer thereon. Laminating a core layer forming resin film to form a core layer, (C) forming a core pattern by exposure and development, and (D) laminating an upper clad layer forming resin film on the core pattern. The method includes a step of forming an upper clad layer. That is, the adhesive layer is first formed on the substrate, and the layers constituting the optical waveguide are stacked thereon.

  In step (A) in the production method of the present invention, as shown in FIG. 1A, a clad layer 4 is formed by laminating a resin film for forming a lower clad layer on a substrate 2 with an adhesive layer 3 interposed therebetween. Is a step of forming. Here, there is no restriction | limiting about the method of forming an adhesive layer, The adhesive composition which comprises the adhesive layer 3 on the base material 2 may be apply | coated directly, and it shows in FIG. As described above, the adhesive layer 31 may be formed in advance on the support base material 32 to produce the adhesive sheet 30, which may be transferred onto the base material 2 and laminated. That is, after peeling off the protective film 33, the adhesive sheet 30 composed of the adhesive layer 31 formed of the adhesive composition, the support base 32, and the protective film 33 provided as desired, In this method, the adhesive layer 3 is formed by laminating the substrate 2 and peeling the support base 32.

The method using the above-mentioned adhesive sheet is excellent in the smoothness of the adhesive layer 3, and the thickness of the adhesive layer can be easily controlled. Moreover, there is no problem that the resin composition for forming the adhesive layer flows in the production process of the adhesive layer, and the production is easy and preferable. In addition, it is preferable that the heating temperature in lamination | stacking shall be 50-130 degreeC, and it is preferable that a crimping | compression-bonding pressure shall be about 0.1-1.0 MPa (1-10 kgf / cm < ² >), However, especially in these conditions, There is no limit. In addition, it is preferable that the protective film 33 and the support base material 32 have not performed the adhesion process in order to make peeling from the adhesive layer 31 easy, and the mold release process may be performed as needed. Details of the adhesive sheet will be described later.
On the other hand, as a method of directly applying the adhesive composition on the substrate, a known method can be used, and for example, it can be applied by a spin coating method or the like.

Next, step (B) in the production method of the present invention is a step of forming the core layer 5 by laminating a resin film for forming a core layer on the lower cladding layer, as shown in FIG. In the next step (C), the core layer 5 is exposed by being irradiated with ultraviolet rays 8 through a photomask pattern 7 as shown in FIG. Then, by developing with a developing solution, as shown in FIG.1 (d), the optical waveguide core pattern 6 is formed.
Next, as step (D), as shown in FIG. 1E, an upper clad layer-forming resin film is laminated on the core pattern 6 to form an upper clad layer, whereby the optical waveguide composite substrate 1 is manufactured. The

  Thus, in the method of the present invention, the adhesive layer 3 is formed on the substrate 2, the lower clad layer 4 is formed thereon, the core layer 5 and the core pattern 6 are formed, and the upper clad layer is formed. 9 is formed by stacking the layers. By adopting such a method, the optical waveguide in which no meandering is observed in the core pattern, excellent in heat resistance, and the optical waveguide is not peeled off from the silicon substrate due to thermal history, and the silicon substrate is not cracked. A composite substrate is manufactured.

Hereinafter, the materials used for each of the steps (A) to (D) will be described in detail.
First, various substrates can be used as the substrate 2 used in the present invention, for example, glass epoxy substrate, organic wiring substrate using polyimide, alumina substrate, aluminum nitride substrate, etc. Ceramic wiring boards, semiconductor wafers such as silicon, metals such as copper and aluminum, and glass materials such as quartz. Of these substrates, the production method of the present invention is particularly suitable for a silicon substrate usually used as a semiconductor wafer.
The thickness of the substrate is appropriately determined according to the application and is not particularly limited. For example, in the case of a silicon substrate, it may be in a range normally used as a semiconductor substrate, and is about 100 μm to 1 mm.

Next, as the adhesive composition for forming the adhesive layer 3, those usually used in the optical field can be used, and the adhesive composition is subjected to the following conditions. The measured storage elastic modulus at 125 ° C. is preferably 10 MPa or less. When the storage elastic modulus is 10 MPa or less, the adhesive layer acts as a stress relaxation layer when the optical waveguide is heated and expanded, so that the optical waveguide is caused by a difference in thermal expansion coefficient between the optical waveguide and the substrate. This is advantageous in that no peeling occurs. From the above viewpoint, it is more preferable that the storage elastic modulus at 125 ° C. is 5 MPa or less.
Moreover, there is no restriction | limiting in particular as thickness of the adhesive agent layer 3, However, 3-200 micrometers is preferable. When the thickness is 3 μm or more, a sufficient stress relaxation effect can be obtained, and when the thickness is 200 μm or less, it is possible to meet the demand for miniaturization of the optical device and it is economically advantageous. From the above viewpoint, the thickness of the adhesive layer is more preferably 5 to 50 μm, further preferably 8 to 30 μm, and particularly preferably 10 to 25 μm.

(Conditions for measuring storage modulus)
The test piece has a length of 20 mm, a width of 4 mm, and a film thickness of 80 μm, and is measured with a temperature rising rate of 5 ° C./min, a tension mode, a frequency of 10 Hz, and an automatic static load.

  The adhesive composition for forming the adhesive layer 3 is not particularly limited as long as it satisfies the above storage elastic modulus condition. Specifically, two or more epoxies are contained in the molecule. Examples thereof include a compound having a group or a compound having an ethylenically unsaturated group in the molecule. These compounds can be used individually by 1 type or in combination of 2 or more types.

  Specific examples of suitable adhesive compositions include (a) a high molecular weight component having a functional group-containing weight average molecular weight of 100,000 or more, (b) an epoxy resin, and (c) a phenolic epoxy. Contains a resin curing agent, (d) a photoreactive monomer having a Tg of 250 ° C. or higher obtained by ultraviolet irradiation, and (e) a photoinitiator that generates bases and radicals by ultraviolet irradiation with a wavelength of 200 to 450 nm. And the like.

Hereinafter, in the present specification, the components (a) and (c) to (e) are respectively represented by (a) a high molecular weight component, (c) an epoxy resin curing agent, (d) a photoreactive monomer, and (e) a photoinitiator. Sometimes abbreviated as agent.
In the present invention, when forming the adhesive layer, it is preferable to use an adhesive sheet as described above. However, when the above components (a) to (e) are used, as shown below. There are significant advantages. That is,
(1) (a) High molecular weight component and (b) epoxy resin can be incompatible depending on the combination, so that a so-called sea-island structure is easy to take, low elasticity, adhesiveness, workability, and reliability at high temperature Is obtained,
(2) Excellent heat resistance and reflow resistance by using (c) epoxy resin curing agent and (d) photoreactive monomer,
(3) (c) an epoxy resin curing agent and (d) a photoinitiator used in the presence of a photoreactive monomer, so that (b) an epoxy resin and (d) light in the absence of light The reactive monomer hardly reacts and is excellent in storage stability. In addition, irradiation with light accelerates the photoreaction and generates an epoxy resin curing accelerator. That is, it is possible to achieve both reactivity and storage stability.

Hereafter, each component which comprises a preferable adhesive composition is demonstrated more concretely.
(A) As a high molecular weight component having a functional group-containing weight average molecular weight of 100,000 or more, a functional group such as a glycidyl group, an acryloyl group, a methacryloyl group, a carboxyl group, a hydroxyl group, or an episulfide group is used in terms of improving adhesiveness. What is contained is preferable, and a glycidyl group is particularly preferable in terms of crosslinkability. Specifically, glycidyl group-containing (meth) containing glycidyl acrylate or glycidyl methacrylate (hereinafter collectively referred to as “glycidyl (meth) acrylate”) as a raw material monomer and having a weight average molecular weight of 100,000 or more. An acrylic copolymer can be mentioned.
Moreover, it is preferable that it is incompatible with (b) epoxy resin at the point of reflow resistance. However, since the compatibility is not determined only by the characteristics of (a) high molecular weight component, a combination in which both are not compatible is selected. In the present invention, the glycidyl group-containing (meth) acrylic copolymer is a phrase indicating both a glycidyl group-containing acrylic copolymer and a glycidyl group-containing methacrylic copolymer.

  As such a copolymer, for example, a (meth) acrylic ester copolymer, acrylic rubber or the like can be used, and acrylic rubber is more preferable. Acrylic rubber is a rubber mainly composed of an acrylate ester and mainly composed of a copolymer such as butyl acrylate and acrylonitrile, a copolymer such as ethyl acrylate and acrylonitrile, or the like. Examples of the copolymer monomer include butyl acrylate, ethyl acrylate, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, acrylonitrile and the like.

  When selecting a glycidyl group as a functional group, it is preferable to use glycidyl (meth) acrylate etc. as a copolymer monomer component. Such a glycidyl group-containing (meth) acrylic copolymer having a weight average molecular weight of 100,000 or more can be produced by appropriately selecting a monomer from the above monomers, or a commercially available product (for example, Nagase ChemteX Corporation). HTR-860P-3, HTR-860P-5, etc.) are also available.

  (A) In the high molecular weight component, since the number of functional groups affects the crosslink density, it varies depending on the resin used. However, when the high molecular weight component is obtained as a copolymer of a plurality of monomers, it contains a functional group used as a raw material. The amount of the monomer is preferably 0.5 to 6% by mass of the copolymer.

  When the glycidyl group-containing acrylic copolymer is used as the component (a), the amount of the glycidyl group-containing monomer such as glycidyl (meth) acrylate used as the raw material and the amount of the glycidyl group-containing repeating unit are 0 of the copolymer. 0.5-6 mass% is preferable, 0.5-5 mass% is more preferable, and 0.8-5 mass% is especially preferable. When the amount of the glycidyl group-containing repeating unit is within this range, the glycidyl group gradually crosslinks, so that an adhesive force can be secured and gelation can be prevented. Moreover, since it becomes incompatible with (b) epoxy resin, it becomes excellent in stress relaxation property.

  Other functional groups may be incorporated into glycidyl (meth) acrylate or the like to form a monomer. The mixing ratio in that case is determined in consideration of the glass transition temperature (hereinafter referred to as “Tg”) of the glycidyl group-containing (meth) acrylic copolymer, and Tg is preferably −10 ° C. or higher. This is because when the Tg is −10 ° C. or higher, the tackiness of the adhesive layer in the B-stage state is appropriate, and there is no problem in handling properties.

  (A) As a high molecular weight component having a functional group-containing weight average molecular weight of 100,000 or more, when the monomer is polymerized and a glycidyl group-containing acrylic copolymer is used, the polymerization method is not particularly limited, For example, methods such as pearl polymerization and solution polymerization can be used.

  In the present invention, the weight average molecular weight of the (a) high molecular weight component is 100,000 or more, preferably 300,000 to 3,000,000, more preferably 400,000 to 2,500,000, and 500,000 to 2,000,000. Is particularly preferred. When the weight average molecular weight is within this range, the strength, flexibility, and tackiness of the sheet or film are appropriate, and the flowability is appropriate, so that followability to the unevenness of the substrate can be ensured. . In the present invention, the weight average molecular weight is a value measured by gel permeation chromatography and converted using a standard polystyrene calibration curve.

  The (b) epoxy resin used in the present invention is not particularly limited as long as it is cured and has an adhesive action. For example, an epoxy resin described in an epoxy resin handbook (edited by Masaki Shinbo, Nikkan Kogyo Shimbun) or the like is used. Can be widely used. Specifically, for example, a bifunctional epoxy resin such as a bisphenol A type epoxy resin, a novolac type epoxy resin such as a phenol novolac type epoxy resin or a cresol novolac type epoxy resin, or the like can be used. Moreover, what is generally known, such as a polyfunctional epoxy resin, a glycidyl amine type epoxy resin, a heterocyclic ring-containing epoxy resin, or an alicyclic epoxy resin, can be applied.

  As such bisphenol A type epoxy resin, which is a kind of epoxy resin, Epicoat 807, 815, 825, 827, 828, 834, 1001, 1004, 1007, 1009 manufactured by Yuka Shell Epoxy Co., Ltd., manufactured by Dow Chemical Co., Ltd. DER-330, 301, 361, YD8125, YDF8170 manufactured by Toto Kasei Co., Ltd. and the like can be mentioned. Examples of the phenol novolac type epoxy resin include Epicoat 152,154 manufactured by Yuka Shell Epoxy Co., Ltd., EPPN-201 manufactured by Nippon Kayaku Co., Ltd., DEN-438 manufactured by Dow Chemical Co., Ltd., and o-cresol novolak type epoxy resin. Examples of the resin include EOCN-102S, 103S, 104S, 1012, 1025, 1027 manufactured by Nippon Kayaku Co., Ltd., YDCN701, 702, 703, 704 manufactured by Toto Kasei Co., Ltd., and the like. As the polyfunctional epoxy resin, Epon 1031S manufactured by Yuka Shell Epoxy Co., Ltd., Araldite 0163 manufactured by Ciba Specialty Chemicals Co., Ltd., Denacor EX-611, 614, 614B, 622, 512, 521, 421, 411 manufactured by Nagase Kasei Co., Ltd. , 321 and the like. As the amine type epoxy resin, Epiquat 604 manufactured by Yuka Shell Epoxy Co., Ltd., YH-434 manufactured by Tohto Kasei Co., Ltd., TETRAD-X, TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd., ELM manufactured by Sumitomo Chemical Co., Ltd. -120 etc. are mentioned. Examples of the heterocyclic ring-containing epoxy resin include ERL4234, 4299, 4221, 4206 and the like manufactured by UCC, such as Araldite PT810 manufactured by Ciba Specialty Chemicals. These epoxy resins can be used alone or in combination of two or more. Moreover, in this invention, in order to provide high adhesive force, a bisphenol A type epoxy resin and a phenol novolak type epoxy resin are preferable.

  As for the usage-amount of (b) epoxy resin of this invention, 5-250 mass parts is preferable with respect to 100 mass parts of (a) high molecular weight component. (B) When the usage-amount of an epoxy resin exists in this range, elastic modulus and the flow control at the time of shaping | molding can be ensured, and the handleability in high temperature is fully obtained. (B) As for the usage-amount of an epoxy resin, 10-100 mass parts is more preferable, and 20-50 mass parts is especially preferable. As already stated, it is preferable that the (b) epoxy resin is not compatible with the (a) high molecular weight component.

  The (c) phenolic epoxy resin curing agent used in the present invention, when combined with an epoxy resin, has excellent impact resistance under high temperature and high pressure, and can maintain sufficient adhesive properties even under severe thermal moisture absorption. It is valid.

  Examples of such component (c) include phenol resins such as phenol novolak resin, bisphenol A novolak resin, and cresol novolak resin. More specifically, for example, manufactured by Dainippon Ink & Chemicals, Inc., trade names: Phenolite LF2882, Phenolite LF2822, Phenolite TD-2090, Phenolite TD-2149, Phenolite VH-4150, Phenolite VH4170 These can be used alone or in combination of two or more.

  In order to provide moisture resistance reliability in the present invention, the amount of component (c) used is such that the equivalent ratio of phenolic hydroxyl groups per epoxy group of (b) epoxy resin is in the range of 0.5 to 1.5. It is preferable that it is 0.8 to 1.2. If the equivalent ratio is within this range, the resin is sufficiently cured (crosslinked), and the heat resistance and moisture resistance of the cured product can be improved.

The photoreactive monomer (d) Tg of the cured product obtained by ultraviolet irradiation used in the present invention is 250 ° C. or higher improves the heat resistance after ultraviolet irradiation of the adhesive sheet described below, and the adhesive force during heating. And reflow resistance can be improved.
(D) As a method for measuring the Tg of the photoreactive monomer, (d) a photoinitiator is added to the photoreactive monomer and ultraviolet-irradiated cured product is molded into a size of about 5 × 5 mm to prepare a sample. . Tg is determined by measuring the prepared sample in a compression mode using EXSTRA6000 manufactured by Seiko Instruments Inc. When Tg is 250 ° C. or higher, the heat resistance is excellent, and it can withstand heat of 250 ° C. or higher in the reflow crack resistance evaluation. Therefore, the reflow crack resistance is good. Tg is more preferably 260 ° C. or higher corresponding to lead-free solder. Moreover, since the thing with too high Tg tends to become inferior in the normal temperature sticking property of the adhesive sheet after ultraviolet irradiation, 350 degreeC is preferable as an upper limit.

  (D) Specific examples of the photoreactive monomer include pentaerythritol triacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, trimethylolpropane triacrylate, isocyanuric acid ethylene oxide (EO) modified triacrylate, ditrile Examples include polyfunctional acrylates such as methylolpropane tetraacrylate and pentaerythritol tetraacrylate. These photoreactive monomers can be used alone or in combination of two or more. Of the polyfunctional acrylates, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, and the like are preferable from the viewpoint of residual monomers after ultraviolet irradiation. Specifically, Shin-Nakamura Chemical Co., Ltd. product name: A-DPH, A-9300, etc. are available.

  In addition, when using several (d) photoreactive monomer, the Tg is Tg when the mixture is measured by the said measuring method, and it is not required that Tg of each monomer is 250 degreeC or more.

  As for the usage-amount of (d) photoreactive monomer of this invention, 5-100 mass parts is preferable with respect to 100 mass parts of (a) high molecular weight component. If this usage amount is 5 parts by mass or more, the polymerization reaction of the photoreactive monomer due to ultraviolet irradiation is likely to occur, so that the peelability of the adhesive sheet from the support substrate tends to be improved. Conversely, if it is 100 parts by mass or less, the low elasticity of the high molecular weight component functions, the film does not become brittle, and the heat resistance and moisture resistance of the cured product tend to be improved. Therefore, 10-70 mass parts is more preferable, and 20-50 mass parts is especially preferable.

  In the present invention, (e) a photoinitiator that generates a base and a radical upon irradiation with ultraviolet rays having a wavelength of 200 to 450 nm is generally called an α-aminoketone compound. Such compounds are described, for example, in J. Org. Photopolym. Sci. Technol, Vol. 13, No. 20001, etc., and reacts as shown in the following formula when irradiated with ultraviolet rays.

  Since the α-aminoketone compound does not have radicals before being irradiated with ultraviolet rays, the polymerization reaction of the photoreactive monomer does not occur. In addition, curing of the thermosetting resin is not accelerated due to steric hindrance. However, the α-aminoketone compound is dissociated by ultraviolet irradiation, and a polymerization reaction of the photoreactive monomer occurs with the generation of radicals. In addition, dissociation of the α-aminoketone compound causes steric hindrance to be reduced and activated amines to be present. For this reason, it is presumed that the amine has a curing accelerating action of the thermosetting resin, and the heating accelerating action is subsequently exerted by heating. By such an action, there is no radical or activated amine before irradiation with ultraviolet rays, so that an adhesive sheet having excellent storage stability at room temperature can be provided. In addition, since the curing rate of the photoreactive monomer or epoxy resin varies depending on the structure of radicals and amines generated by ultraviolet irradiation, (e) a photoinitiator (base generator) depending on the components (b) to (d) used. Can be determined.

  Examples of the (e) photoinitiator (base generator) include 2-methyl-1 (4- (methylthio) phenyl-2-morpholinopropan-1-one (Irgacure 907 manufactured by Ciba Specialty Chemicals), 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (Irgacure 369 manufactured by Ciba Specialty Chemicals), hexaarylbisimidazole derivative (halogen, alkoxy group, nitro group, cyano A substituent such as a group may be substituted with a phenyl group), a benzoisoxazolone derivative, or the like.

  In addition to the photoinitiator (base generator), a method of generating a base by photo-Fries rearrangement, photo-Claisen rearrangement, Curtius rearrangement, or Stevens rearrangement can be used.

  The photoinitiator (base generator) may be a low molecular compound having a molecular weight of 500 or less, or a compound introduced into a main chain and side chain of a polymer. The molecular weight in this case is preferably a weight average molecular weight of 1,000 to 100,000, more preferably 5,000 to 30,000 from the viewpoints of adhesiveness and fluidity as an adhesive.

  In the adhesive composition of the present invention, the amount of the (e) photoinitiator used is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the (a) high molecular weight component. If it is 0.1 part by mass or more, the reactivity is good and the residual monomer is reduced, and if it is 20 parts by mass or less, the molecular weight increase due to the polymerization reaction functions moderately, and there are few low molecular weight components, affecting the reflow resistance. The possibility of exerting is reduced. Therefore, it is more preferably 0.5 to 15 parts by mass, and still more preferably 1 to 5 parts by mass.

  Next, in addition to the components (a) to (e), components that can be contained in the adhesive layer will be described. For the purpose of improving flexibility and reflow crack resistance, (f) a high molecular weight resin compatible with an epoxy resin can be added to the adhesive resin composition of the present invention. As such a high molecular weight resin, those which are incompatible with the high molecular weight component (a) are preferable from the viewpoint of improving reliability, and examples thereof include phenoxy resin, high molecular weight epoxy resin, and ultra high molecular weight epoxy resin. These can be used alone or in combination of two or more. (B) When using an epoxy resin that is compatible with (a) a high molecular weight component, when (f) a high molecular weight resin compatible with the epoxy resin is used, (b) the epoxy resin is As a result, it may be possible to make (b) the epoxy resin and (a) the high molecular weight component incompatible with each other.

  (F) It is preferable that the usage-amount of high molecular weight resin compatible with an epoxy resin shall be 40 mass parts or less with respect to a total of 100 mass parts of (b) epoxy resin and (c) epoxy resin hardening | curing agent. Within this range, the Tg of the adhesive layer can be secured.

  In addition, various coupling agents can be added to the adhesive composition of the present invention in order to improve interfacial bonding between different materials. Examples of the coupling agent include silane, titanium, and aluminum.

  The silane coupling agent is not particularly limited. For example, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-ureidopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane and the like can be used, and these can be used alone or in combination of two or more. Specifically, there are NUCA-189 and NUCA-1160 manufactured by Nippon Unicar Co., Ltd.

  The amount of the coupling agent used is from 0.01 to 100 parts by mass of (a) a high molecular weight component having a functional group-containing weight average molecular weight of 100,000 or more from the viewpoint of its effect, heat resistance and cost. The amount is preferably 10 parts by mass.

  In the adhesive composition of the present invention, an ion scavenger can be further added in order to adsorb ionic impurities and improve moisture resistance reliability. Such an ion scavenger is not particularly limited, for example, triazine thiol compound, bisphenol-based reducing agent, etc., a compound known as a copper damage preventing agent for preventing copper ionization and dissolution, zirconium-based And inorganic ion adsorbents such as antimony bismuth-based magnesium aluminum compounds.

  The amount of the ion scavenger used is from the viewpoint of the effect of addition, heat resistance, cost, etc. to (a) 100 parts by mass of the high molecular weight component having a functional group-containing weight average molecular weight of 100,000 or more. 1-10 mass parts is preferable.

  The adhesive sheet according to the present invention is obtained by dissolving or dispersing the adhesive composition in a solvent to obtain a varnish, which is applied onto a base film (support base material), heated and then removed. Can do.

  That is, as shown in FIG. 2, first, a film obtained by dissolving an adhesive composition in an organic solvent or the like on a protective film 33 (also referred to as a release sheet) to form a varnish is used. The adhesive layer 31 is formed by coating and drying in accordance with generally known methods such as spray coating, gravure coating, bar coating, and curtain coating. Then, the support base material 32 is laminated | stacked and the adhesive sheet 30 which consists of a release sheet (protective film 33), the adhesive layer 31, and the support base material 32 can be obtained. Alternatively, the adhesive composition can be obtained by applying the adhesive composition directly on the supporting substrate in the same manner and drying it. In this case, you may laminate | stack a protective film as needed.

  Examples of the protective film or supporting substrate used in the adhesive sheet of the present invention include plastic films such as polytetrafluoroethylene film, polyethylene film, polypropylene film, and polymethylpentene film, and polyester such as polyethylene terephthalate. . Here, as will be described later, the adhesive sheet is irradiated with ultraviolet rays, the ultraviolet-curing adhesive is polymerized and cured, and the adhesive force at the interface between the adhesive and the supporting substrate is lowered to form a supporting group. Allows stripping of material. For this reason, the support substrate is preferably one having ultraviolet transparency.

  The solvent for varnishing is not particularly limited as long as it is an organic solvent, but can be determined in consideration of the volatility during film production from the boiling point. Specifically, for example, a solvent having a relatively low boiling point such as methanol, ethanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone, toluene, xylene is used at the time of film production. This is preferable in that curing of the resin does not proceed. For the purpose of improving the coating properties, it is preferable to use a solvent having a relatively high boiling point such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, cyclohexanone. These solvents can be used alone or in combination of two or more.

  The thickness of the support substrate is not particularly limited, but is preferably 5 to 250 μm. If it is 5 micrometers or more, workability | operativity will improve, and if it is 250 micrometers or less, it is economical and preferable. From the above viewpoint, the thickness of the supporting base material is more preferably 10 to 200 μm, further preferably 20 to 150 μm, and particularly preferably 25 to 125 μm.

The total thickness of the adhesive layer and the supporting substrate is usually 10 to 250 μm. The workability is good when the support substrate is set to be the same as or slightly thicker than the adhesive layer. As a specific combination, the adhesive layer / support substrate (μm) is 5/25, 10/30, 10 / There are 50, 25/50, 50/50, 50/75, etc., which can be appropriately determined according to the conditions and apparatus used.
Further, the adhesive sheet according to the present invention is a separately prepared adhesive agent on the adhesive layer side of the adhesive sheet in order to obtain a desired thickness and to improve fluidity during heating. Two or more sheets can be bonded together. In this case, it is necessary to select a bonding condition so that peeling between the adhesive layers does not occur.

  When the adhesive sheet having the structure as described above is irradiated with ultraviolet rays, the adhesive strength of the support base material is greatly reduced after the ultraviolet irradiation, and the adhesive sheet of the adhesive sheet is retained while holding the adhesive layer on the substrate. The supporting substrate can be easily peeled off.

Next, the optical waveguide forming resin film (hereinafter referred to as the cladding layer forming resin film) used for the cladding layer of the present invention is manufactured using the cladding layer forming resin, and, if necessary, the cladding layer. It is manufactured by applying a layer forming resin to a base film.
The resin film for forming an optical waveguide used for the core layer of the present invention (hereinafter referred to as a resin film for forming a core layer) is produced using a resin for forming a core layer. It is manufactured by applying a forming resin to a base film.

  In the optical waveguide forming resin film used in the optical waveguide of the present invention, the cured product of the core layer forming resin film is designed to have a higher refractive index than the cured product of the optical waveguide forming resin film used in the cladding layer. .

As the clad layer forming resin used in the clad layer forming resin film of the present invention, the cured product of the clad forming resin film has a lower refractive index than the cured product of the core layer forming resin film, and light or The resin is not particularly limited as long as it is a resin curable by heat, and a thermosetting resin or a photosensitive resin can be used.
The clad layer forming resin is preferably composed of a resin composition containing (a) a base polymer, (b) a photopolymerizable compound, and (c) a photopolymerization initiator.

The (a) base polymer used here is for forming a clad layer and ensuring the strength of the clad layer, and is not particularly limited as long as the object can be achieved, phenoxy resin, epoxy resin (Meth) acrylic resin, polycarbonate resin, polyarylate resin, polyether amide, polyether imide, polyether sulfone, or derivatives thereof.
The (meth) acrylic resin means an acrylic resin and a methacrylic resin.
These base polymers may be used independently and may use 2 or more types together.

From the viewpoint of high heat resistance, the (a) base polymer is preferably a resin having an aromatic skeleton in the main chain, and particularly preferably a phenoxy resin.
From the viewpoint of three-dimensional crosslinking and improving heat resistance, an epoxy resin, particularly an epoxy resin that is solid at room temperature is preferable.
Furthermore, as (a) the base polymer, compatibility with the photopolymerizable compound (b) described later is important in order to ensure the transparency of the resin film for forming the clad layer. Resins and / or (meth) acrylic resins are preferred.

Among the above phenoxy resins, those containing bisphenol A or a bisphenol A type epoxy compound or a derivative thereof, and bisphenol F or a bisphenol F type epoxy compound or a derivative thereof as a constituent unit of a copolymer component are heat resistant, adhesive and It is more preferable because of its excellent solubility.
Preferred examples of the bisphenol A or bisphenol A type epoxy compound include tetrabromobisphenol A and tetrabromobisphenol A type epoxy compounds.
Moreover, as a derivative of bisphenol F or a bisphenol F type epoxy compound, tetrabromobisphenol F, a tetrabromobisphenol F type epoxy compound, etc. are mentioned suitably.
Specific examples of the bisphenol A / bisphenol F copolymer type phenoxy resin include “Phenotote YP-70” (trade name) manufactured by Toto Kasei Co., Ltd.

Further, as the (a) base polymer, an epoxy resin, particularly an epoxy resin that is solid at room temperature is preferable from the viewpoint of three-dimensional crosslinking and improving heat resistance as described above.
Examples of the epoxy resin that is solid at room temperature include, for example, “Epototo YD-7020, Epototo YD-7019, Epototo YD-7007” (all trade names) manufactured by Toto Chemical Co., Ltd., and “Epicoat 1010” manufactured by Japan Epoxy Resins Co., Ltd. Bisphenol A type epoxy resin such as “Epicoat 1009, Epicoat 1008” (both trade names).

(A) The molecular weight of the base polymer is usually 5,000 or more in terms of number average molecular weight from the viewpoint of film forming properties. The number average molecular weight is preferably 10,000 or more, more preferably 30,000 or more.
The upper limit of the number average molecular weight is not particularly limited, but is usually 1,000,000 or less from the viewpoint of (a) compatibility with the photopolymerizable compound and exposure and developability.
The upper limit of the number average molecular weight is preferably 500,000 or less, more preferably 200,000 or less.
The number average molecular weight is a value measured by gel permeation chromatography (GPC) and converted to standard polystyrene.

(A) The compounding quantity of a base polymer is about 10-80 mass% normally with respect to the total amount of the base polymer of (a) component, and the photopolymerizable compound of (a) component.
When the blending amount is 10% by mass or more, there is an advantage that it is easy to form a thick film having a thickness of about 50 to 500 μm necessary for forming an optical waveguide. Proceed sufficiently.
From the above viewpoint, the amount of component (a) is preferably 20 to 70 mass%, more preferably 25 to 65 mass%.

Next, (a) the photopolymerizable compound is not particularly limited as long as it is polymerized by irradiation with light such as ultraviolet rays, and a compound having two or more epoxy groups in the molecule or an ethylenically non-polymerizable compound in the molecule. Examples thereof include compounds having a saturated group.
Specific examples of compounds having two or more epoxy groups in the molecule include bisphenol A type epoxy resins, tetrabromobisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD type epoxy resins, naphthalene type epoxy resins, etc. Polyfunctional aromatic glycidyl ether such as bifunctional aromatic glycidyl ether, phenol novolac type epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene-phenol type epoxy resin, tetraphenylolethane type epoxy resin, polyethylene glycol type epoxy resin, Bifunctional aliphatic glycidyl ether such as polypropylene glycol type epoxy resin, neopentyl glycol type epoxy resin, hexanediol type epoxy resin, hydrogenated bisphenol A type Bifunctional aromatic glycidyl ethers such as bifunctional alicyclic glycidyl ethers such as poxy resins, polyfunctional aliphatic glycidyl ethers such as trimethylolpropane type epoxy resins, sorbitol type epoxy resins and glycerin type epoxy resins, and diglycidyl esters of phthalic acid , Bifunctional alicyclic glycidyl esters such as tetrahydrophthalic acid diglycidyl ester and hexahydrophthalic acid diglycidyl ester, bifunctional aromatic glycidyl such as N, N-diglycidyl aniline and N, N-diglycidyl trifluoromethylaniline Amine, N, N, N ′, N′-tetraglycidyl-4,4-diaminodiphenylmethane, 1,3-bis (N, N-glycidylaminomethyl) cyclohexane, N, N, O-triglycidyl-p-amino Polyfunctionality such as phenol Bifunctional cycloaliphatic epoxy resins such as aromatic glycidylamine, alicyclic diepoxy acetal, alicyclic diepoxy adipate, alicyclic diepoxycarboxylate, vinylcyclohexene dioxide, and bifunctional heterocycles such as diglycidylhydantoin And a bifunctional or polyfunctional silicon-containing epoxy resin such as an epoxy resin, a polyfunctional heterocyclic epoxy resin such as triglycidyl isocyanurate, and an organopolysiloxane type epoxy resin.

These compounds having two or more epoxy groups in the molecule are usually those having a molecular weight of 100 to 2000 and liquid at room temperature. The molecular weight is preferably 150 to 1,000, more preferably 200 to 800.
Moreover, these compounds may be used independently, may be used together 2 or more types, and also can be used in combination with another photopolymerizable compound.
The molecular weight can be measured using a gel permeation chromatography (GPC) method or a mass spectrometry method.

  Specific examples of the compound having an ethylenically unsaturated group in the molecule include (meth) acrylate, vinylidene halide, vinyl ether, vinyl pyridine, and vinyl phenol. Among these, transparency and heat resistance From the viewpoint, (meth) acrylate is preferable, and any of monofunctional, bifunctional, trifunctional or higher can be used.

  Monofunctional (meth) acrylates include methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, lauryl (meth) acrylate, isostearyl (meth) acrylate, and 2- (meth) acryloyloxyethyl succinic acid. , Paracumylphenoxyethylene glycol (meth) acrylate, 2-tetrahydropyranyl (meth) acrylate, isobornyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, benzyl (meth) acrylate Etc.

  Further, as the bifunctional (meth) acrylate, ethoxylated 2-methyl-1,3-propanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) Acrylate, 2-methyl-1,8-octanediol diacrylate, 1,9-nonanediol di (meth) acrylate, 1,10-nonanediol di (meth) acrylate, ethoxylated polypropylene glycol di (meth) acrylate, propoxy Ethoxylated bisphenol A diacrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol Di (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, tricyclodecane di (meth) acrylate, ethoxylated cyclohexanedimethanol di (meth) acrylate, 2-hydroxy-1-acryloxy-3-methacryloxypropane, 2-hydroxy-1,3-dimethacryloxypropane, 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene, 9,9-bis [3-phenyl-4-acryloylpolyoxyethoxy) fluorene Bisphenol A type, phenol novolak type, cresol novolak type, and glycidyl ether type epoxy (meth) acrylate.

Furthermore, as tri- or more functional (meth) acrylate, ethoxylated isocyanuric acid tri (meth) acrylate, ethoxylated glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, propoxylated pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, caprolactone modified ditri Examples include methylolpropane tetraacrylate and dipentaerythritol hexa (meth) acrylate.
These may be used alone or in combination of two or more.
Here, (meth) acrylate means acrylate and methacrylate.

(A) The compounding quantity of a photopolymerizable compound is about 20-90 mass% normally with respect to the total amount of the base polymer of (A) component, and the photopolymerizable compound of (A) component.
When the blending amount is 20% by mass or more, the base polymer can be easily entangled and cured in the photopolymerizable compound, while when it is 90% by mass or less, a sufficiently thick clad layer can be easily formed. Can be formed.
From the above viewpoint, the amount of component (a) is preferably 25 to 85% by mass, more preferably 30 to 80% by mass.

  Next, the photopolymerization initiator of the component (c) is not particularly limited. For example, as an initiator of an epoxy compound, an aryldiazonium salt such as p-methoxybenzenediazonium hexafluorophosphate, diphenyliodonium hexafluorophosphonium salt, diphenyl Diaryliodonium salts such as iodonium hexafluoroantimonate salt, triphenylsulfonium hexafluorophosphonium salt, triphenylsulfonium hexafluoroantimonate salt, diphenyl-4-thiophenoxyphenylsulfonium hexafluoroantimonate salt, diphenyl-4-thiophenoxyphenyl Sulfonium hexafluoroantimonate salt, diphenyl-4-thiophenoxyphenylsulfonium pentafluorohydroxyantimonate salt Any triarylsulfonium salt, triphenylselenonium hexafluorophosphonium salt, triphenylselenonium borofluoride, triarylselenonium salt such as triphenylselenonium hexafluoroantimonate salt, dimethylphenacylsulfonium hexafluoroantimonate salt, Dialkylphenazylsulfonium salts such as diethylphenacylsulfonium hexafluoroantimonate salt, dialkyl-4-hydroxyphenylsulfonium salts such as 4-hydroxyphenyldimethylsulfonium hexafluoroantimonate salt, 4-hydroxyphenylbenzylmethylsulfonium hexafluoroantimonate , Α-hydroxymethylbenzoin sulfonic acid ester, N-hydroxyimide sulfonate, α-sulfonilo Shiketon, sulfonic acid esters such as β- sulfo Niro carboxymethyl ketone.

Moreover, as an initiator of the compound having an ethylenically unsaturated group in the molecule, benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4 '-Diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2,2-dimethoxy-1,2 -Diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy- 2-Methyl-1-propan-1-one, 1,2-methyl-1- [4- (methylthio) phenyl] -2-morph Aromatic ketones such as linopropan-1-one, 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2 Quinones such as 1,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone Benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether and benzoin phenyl ether, benzoin compounds such as benzoin, methyl benzoin and ethyl benzoin; benzyldimethyl ketal and the like 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluoro) Phenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer 2,4,5-triarylimidazole dimer such as bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide Phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, - phenyl acridine, 1,7-bis (9,9'-acridinyl) acridine derivatives such as heptane, N- phenylglycine, N- phenylglycine derivatives, coumarin-based compounds.
In addition, in the 2,4,5-triarylimidazole dimer, when the aryl group is substituted, the substituents of the two aryl groups may be the same and symmetrical dimers, It may be an asymmetric dimer.
Moreover, you may combine a thioxanthone type compound and a tertiary amine compound like the combination of diethyl thioxanthone and dimethylaminobenzoic acid.
In addition, from the viewpoint of improving the transparency of the core layer and the cladding layer, aromatic ketones and phosphine oxides are preferable among the photopolymerization initiators.
These (c) photopolymerization initiators may be used alone or in combination of two or more.

(U) The compounding quantity of a photoinitiator is about 0.1-10 mass parts normally with respect to 100 mass parts of base polymer of (A) component, and the photopolymerizable compound total amount of (I) component.
If it is 0.1 parts by mass or more, the photosensitivity is sufficient, while if it is 10 parts by mass or less, only the surface of the optical waveguide is selectively cured, the curing does not become insufficient, Propagation loss does not increase due to absorption of the photopolymerization initiator itself.
From the above viewpoint, the amount of component (c) is preferably 0.5 to 5 parts by mass, more preferably 1 to 4 parts by mass.

  In addition, if necessary, the clad layer forming resin of the present invention includes an antioxidant, an anti-yellowing agent, an ultraviolet absorber, a visible light absorber, a colorant, a plasticizer, a stabilizer, and a filler. You may add what is called additives, such as an agent, in the ratio which does not have a bad influence on the effect of this invention.

The resin for forming the clad layer is used as a resin varnish for forming the clad layer by dissolving a resin composition containing (a) a base polymer, (b) a photopolymerizable compound, and (c) a photopolymerization initiator in a solvent. You can also
The resin film for forming a clad layer can be easily produced by applying a resin varnish for forming a clad layer on a base film, if necessary, and removing the solvent.

In the production process of the clad layer forming resin film, the base film used as necessary is a support for supporting the optical waveguide forming film, and the material thereof is not particularly limited. For example, the clad layer forming resin film From the standpoint of easy peeling and having heat resistance and solvent resistance, polyesters such as polyethylene terephthalate (PET), polypropylene, and polyethylene are preferably used.
The base film may be subjected to a release treatment, an antistatic treatment, or the like in order to facilitate later peeling of the clad layer forming resin film.
The thickness of the base film is usually 5 to 50 μm. When the thickness of the base film is 5 μm or more, there is an advantage that the strength as a support is easily obtained, and when it is 50 μm or less, there is an advantage that the winding property in the case of manufacturing in a roll shape is improved. From the above viewpoint, the thickness of the base film is preferably 10 to 40 μm, more preferably 15 to 30 μm.

Furthermore, a protective film may be bonded to the resin film for forming a clad layer in consideration of film protection and roll-up property when manufactured in a roll shape.
As a protective film, the thing similar to what was mentioned as an example of the said base film can be used, and the mold release process and the antistatic process may be performed as needed.

The solvent used in the clad layer-forming resin varnish is not particularly limited as long as it can dissolve the resin composition containing the components (a) to (c). For example, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve , Toluene, N, N-dimethylacetamide, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, N-methyl-2-pyrrolidone, or a mixed solvent thereof can be used.
The solid content concentration in the resin varnish for forming a clad layer is usually 30 to 80% by mass, preferably 35 to 75% by mass, and more preferably 40 to 70% by mass.

The thickness of the resin film for forming a clad layer is not particularly limited, but the thickness of the clad layer after drying is usually adjusted to 5 to 500 μm. When the thickness of the cladding layer is 5 μm or more, the thickness of the cladding layer necessary for light confinement can be secured, and when it is 500 μm or less, the thickness of the cladding layer can be easily controlled uniformly. From the above viewpoint, the thickness of the cladding layer is preferably 10 to 100 μm, more preferably 20 to 90 μm.
The thickness of the clad layer may be the same or different between the lower clad layer formed first and the upper clad layer for embedding the core pattern. The thickness of the layer is preferably larger than the thickness of the core layer.
The clad layer can also be easily produced by applying a clad layer forming resin varnish on the ultraviolet absorbing layer by spin coating or the like and removing the solvent.

Next, the resin film for forming a core layer used in the present invention is designed such that the core layer has a higher refractive index than that of the cladding layer, and a resin composition capable of forming a core pattern with ultraviolet rays can be used. Resin compositions are preferred.
Specifically, it is preferable to use the same resin composition as that used for the cladding layer forming resin.
That is, it is a resin composition containing the (a) base polymer, (b) a photopolymerizable compound, and (c) a photopolymerization initiator, and, if necessary, the above optional components.

The resin for core layer formation is used as a resin varnish for core layer formation by dissolving a resin composition containing (a) a base polymer, (b) a photopolymerizable compound and (c) a photopolymerization initiator in a solvent. You can also.
The core layer-forming resin film can be easily produced by applying the core layer-forming resin varnish on the base film, if necessary, and removing the solvent. In the production process of the core layer forming resin film, the base film used as necessary is a support for supporting the optical waveguide forming film, and the material thereof is not particularly limited, and the production of the clad layer forming resin film is performed. The same base film used in the process can be used.
For example, polyesters such as polyethylene terephthalate (PET), polypropylene, polyethylene, and the like are preferably used from the viewpoint that it is easy to peel off the resin film for forming the core layer and has heat resistance and solvent resistance. Can do.

Moreover, it is preferable to use a highly transparent flexible base film in order to improve the transmittance of exposure light and reduce the side wall roughness of the core pattern. The haze value of the highly transparent base film is usually 5% or less, preferably 3% or less, more preferably 2% or less.
As such a base film, Toyobo Co., Ltd. product name "Cosmo Shine A1517" and "Cosmo Shine A4100" are available.
The base film may be subjected to a release treatment, an antistatic treatment or the like in order to facilitate later peeling of the core layer forming resin film.

  The thickness of the base film is usually 5 to 50 μm. When the thickness of the base film is 5 μm or more, there is an advantage that the strength as a support is easily obtained, and when it is 50 μm or less, the gap with the mask at the time of pattern formation becomes small, and a finer pattern is formed. There is an advantage that you can. From the above viewpoint, the thickness of the base film is preferably 10 to 40 μm, more preferably 15 to 30 μm.

  Moreover, you may affix a protective film to the resin film for core layer formation as needed, such as protection of the resin film for core layer formation, and the winding property in the case of manufacturing in roll shape. As a protective film, the thing similar to the base film used in the resin film for clad layer formation can be used, and the mold release process and the antistatic process may be performed as needed.

The solvent used for the resin varnish for forming the core layer is not particularly limited as long as it can dissolve the resin composition containing the components (a) to (c). For example, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve , Toluene, N, N-dimethylacetamide, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, N-methyl-2-pyrrolidone, or a mixed solvent thereof can be used.
The solid content concentration in the resin varnish for forming the core layer is usually 30 to 80% by mass, preferably 35 to 75% by mass, and more preferably 40 to 70% by mass.

The thickness of the resin film for forming the core layer is not particularly limited, but the thickness of the core layer after drying is usually adjusted to be 10 to 100 μm. When the thickness of the core layer is 10 μm or more, there is an advantage that the alignment tolerance can be increased in the coupling with the light emitting / receiving element or the optical fiber after the optical waveguide is formed, and when the thickness is 100 μm or less, the light receiving after the optical waveguide is formed. There is an advantage that coupling efficiency is improved in coupling with a light emitting element or an optical fiber. From the above viewpoint, the thickness of the core layer is preferably 29 to 90 μm, more preferably 30 to 80 μm.
The core layer can also be easily manufactured by applying a resin varnish for forming a core layer on the clad layer by spin coating or the like and removing the solvent.

Hereinafter, the manufacturing method of the optical waveguide composite substrate of this invention is demonstrated using FIG. The lamination of the adhesive layer 3 is as described above.
Next, as step (A) (see FIGS. 1A and 2), a clad layer-forming resin film 41 as shown in FIG. 4 is laminated. Here, it is preferable to laminate | stack under reduced pressure from the viewpoint of adhesiveness and followable | trackability, The conditions are the same as the case where the above-mentioned adhesive layer is laminated | stacked. Moreover, in the resin film for clad layer formation, when the protective film 43 is provided on the opposite side of the base film 42 (see FIG. 3), the resin film 42 for clad layer formation is removed after the protective film 43 is peeled off. The pressure-sensitive adhesive layer 3 is heat-pressed and cured by light or heat to form the clad layer 4.
In this case, the protective film 43 and the base film 42 are preferably not subjected to an adhesive treatment in order to facilitate peeling from the clad layer forming resin film 41, and may be subjected to a release treatment as necessary. Good (see a and b in FIG. 3).

Next, as a step (B) (see FIG. 1B), the core layer forming resin film 51 is laminated on the clad layer 4, and the core layer 5 is laminated.
In this step (B), when the base film 42 is present on the clad layer 4, the core film forming resin film 51 is thermocompression-bonded after being peeled off, so that the refractive index is higher than that of the clad layer 4. A high core layer 5 is laminated. Here, it is preferable to laminate | stack under reduced pressure from the viewpoint of adhesiveness and followable | trackability.
The heating temperature in the lamination is preferably 50 to 130 ° C., and the pressing pressure is preferably about 0.1 to 1.0 MPa (1 to 10 kgf / cm ² ), but these conditions are not particularly limited. Absent.

As shown in FIG. 4, when the core layer forming resin film 51 is composed of the core layer 5 and the base film 52, it is easy to handle, but may be composed of the core layer 5 alone. .
In the core layer forming resin film 51, when the protective film 53 is provided on the opposite side of the base film 52 (see FIG. 4), the core layer forming resin film 51 is laminated after the protective film 53 is peeled off. To do. In this case, the protective film 53 and the base film 52 are preferably not subjected to an adhesive treatment in order to facilitate the peeling from the core layer 5, and may be subjected to a mold release treatment as necessary (FIG. 5). C and d).

Next, as a step (C) (see FIGS. 1C and 1D), the core layer 5 is exposed and developed to form the optical waveguide core pattern 6. Specifically, the ultraviolet rays 8 are irradiated in an image form through the photomask pattern 7.
Examples of the ultraviolet light source include known light sources that effectively emit ultraviolet light, such as a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, and a xenon lamp.

Next, when the base film 52 remains on the core layer 5, the base film 52 is peeled off, and the unexposed portion is removed and developed by wet development or the like to form the optical waveguide core pattern 6.
In the case of wet development, using an organic solvent-based developer or alkali developer suitable for the composition of the core layer-forming resin film or core layer-forming resin varnish, spraying, rocking immersion, brushing, scraping, etc. Develop by the method of.

Examples of the organic solvent developer include N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, γ-butyrolactone, methyl cellosolve, ethyl cellosolve, propylene glycol monomethyl Examples include ether and propylene glycol monomethyl ether acetate.
These organic solvents may add water in the range of usually 1 to 20 parts by mass with respect to 100 parts by mass of the organic solvent in order to prevent ignition.

  As the alkaline developer, an alkaline aqueous solution, an aqueous developer, or the like can be used, and the base of the alkaline aqueous solution is not particularly limited. For example, alkali hydroxide such as lithium, sodium or potassium hydroxide; lithium Carbonates such as sodium, potassium or ammonium carbonates or bicarbonates; alkali metal phosphates such as potassium phosphate and sodium phosphate; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; borax Sodium salts such as sodium metasilicate; tetramethylammonium hydroxide, triethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1,3-diaminopropanol-2-morpholine, etc. The organic Such as a group, and the like.

The pH of the alkaline aqueous solution used for development is preferably 9 to 11, and the temperature is adjusted in accordance with the developability of the core portion-forming resin composition layer.
Further, in the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like may be mixed.
Among these, lithium carbonate, sodium carbonate, and potassium carbonate aqueous solution are particularly preferable because they are less irritating to the human body and less burden on the environment.

If necessary, an organic solvent can be used in combination with the alkaline aqueous solution. The organic solvent here is not particularly limited as long as it is miscible with an alkaline aqueous solution. For example, alcohol such as methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol; acetone, 4-hydroxy-4-methyl Ketones such as 2-pentanone; polyhydric alcohol alkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether Is mentioned.
These can be used alone or in combination of two or more.

  As the processing after development, the core portion of the optical waveguide may be cleaned using a cleaning liquid composed of water and the organic solvent as necessary. An organic solvent can be used individually or in combination of 2 or more types. In general, the concentration of the organic solvent is preferably 2 to 90% by mass, and the temperature is adjusted in accordance with the developability of the core portion-forming resin composition.

Examples of the developing method include a dip method, a battle method, a spray method such as a high-pressure spray method, brushing, and scraping. The high-pressure spray method is most suitable for improving the resolution.
Moreover, you may use together 2 or more types of image development methods as needed.
As the processing after development, the optical waveguide core pattern may be further cured and used by heating at about 60 to 250 ° C. or exposure at about 0.1 to 1,000 mJ / cm ² as necessary. .

Thereafter, as a step (D) (see FIG. 1 (e)), a step of laminating the resin film 91 for forming the upper clad layer (see FIG. 5) for embedding the core pattern 6, and the resin film for forming the upper clad layer The step of curing the clad layer forming resin layer 9 ′ 91 to form the upper clad layer 9 is performed.
In the lamination, when the clad layer forming resin layer 9 ′ is formed on the base film 92, the clad layer forming resin layer 9 ′ is on the core pattern 6 side.
In this case, the thickness of the upper clad layer 9 is preferably larger than the thickness of the core layer 5 as described above.
Curing is performed by light or heat in the same manner as described above.

In the clad layer forming resin film 91, when the protective film 93 is provided on the opposite side of the base film 92 (see FIG. 5), the clad layer forming resin film 91 is heated after peeling off the protective film 93. The clad layer 9 is formed by pressure bonding and curing by light or heating. In this case, the base film 92 may be peeled off or may be left bonded if necessary.
In the case where it is still bonded, it is preferable that the clad layer forming resin layer 9 ′ is formed on the base film 92 subjected to the adhesion treatment.
On the other hand, the protective film 93 is preferably not subjected to an adhesive treatment in order to facilitate peeling from the clad layer forming resin film 91, and may be subjected to a release treatment as necessary (e in FIG. 5). And f).

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
(Evaluation methods)
1. Optical Loss by Thermal Cycle Test For the optical waveguide composite substrate manufactured in Example 1 and Comparative Example 1, 100 cycles of -55 ° C. to 125 ° C. heat shock were applied, and the insertion loss of light after the initial and 100 cycles was measured. . For Example 1, the insertion loss of light after 1000 cycles was also measured.
[Preparation of test sample]
In Example 1, using a dicing saw (dicing saw "DAD-341" manufactured by DISCO) from the manufactured optical waveguide composite substrate, the waveguide length is processed to be 10 cm, and a test for evaluating insertion loss is performed. A sample was made. On the other hand, in the comparative example 1, it processed so that it might become waveguide length 5cm using the same apparatus.
[Optical waveguide insertion loss]
A cut-back method (measurement waveguide lengths 10, 5, 3, and 5) using a surface-emitting laser of 850 nm (exfo, FLS-300-01-VCL) as the light source and Q82214 manufactured by Advantest Co., Ltd. as the light receiving sensor. 2 cm, incident fiber: GI-50 / 125 multimode fiber (NA = 0.20), output fiber: SI-114 / 125 (NA = 0.22)).

2. Maximum Displacement About the optical waveguide composite substrate manufactured in Example 1 and Comparative Example 2, the degree of meandering of the core pattern 6 was observed with an optical microscope. As shown in FIG. 6, the maximum displacement amount X was evaluated with respect to a linear distance Y (10 cm) between two points having the core pattern. Both Example 1 and Comparative Example 2 were measured 16 times, and Comparative Example 2 showed its maximum and minimum values.

Example 1
(1) Production of an adhesive sheet (a) As a high molecular weight component, HTR-860P-3 (trade name manufactured by Teikoku Chemical Industry Co., Ltd., glycidyl group-containing acrylic rubber, molecular weight 1 million, Tg-7 ° C.) 100 mass Parts, (b) As an epoxy resin, YDCN-703 (trade name, manufactured by Toto Kasei Co., Ltd., o-cresol novolac type epoxy resin, epoxy equivalent 210), 5.4 parts by mass, YDCN-8170C (manufactured by Toto Kasei Co., Ltd.) Product name, bisphenol F type epoxy resin, epoxy equivalent 157) 16.2 parts by mass, (c) as epoxy resin curing agent, Phenolite LF2882 (trade name, bisphenol A novolak resin, manufactured by Dainippon Ink and Chemicals, Ltd., hydroxyl group) Equivalent 118 g / eq) 15.3 parts by mass, as silane coupling agent, NUCA-189 (Nippon Unicar Co., Ltd. product) Name, 0.1 part by mass of γ-mercaptopropyltrimethoxysilane) and 0.3 part by mass of NUCA-1160 (trade name, 3-ureidopropyltriethoxysilane, manufactured by Nippon Unicar Co., Ltd.), (d) photoreactivity As a monomer, 30 parts by mass of A-DPH (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd., dipentaerythritol hexaacrylate), (e) Irgacure 369 (trade name, manufactured by Ciba Specialty Chemicals Co., Ltd., 2) as a photobase generator -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one: I-369) 1.5 parts by mass, cyclohexanone as an organic solvent was added, mixed by stirring, and vacuum degassed. This adhesive resin composition varnish was applied onto a 75 μm-thick surface release-treated polyethylene terephthalate (manufactured by Teijin Ltd., Teijin Tetron film: A-31), and dried by heating at 80 ° C. for 30 minutes. An adhesive sheet was obtained. This adhesive sheet is laminated together with an 80 μm-thick UV transparent support substrate (manufactured by Thermo Co., Ltd., low density polyethylene terephthalate / vinyl acetate / low density polyethylene terephthalate three-layer film: FHF-100). Thus, an adhesive sheet composed of a protective film (the surface release-treated polyethylene terephthalate), an adhesive layer, and an ultraviolet transmissive supporting substrate was prepared.
The storage elastic modulus of the adhesive resin composition obtained by irradiating the adhesive sheet 1 with ultraviolet light of 365 nm at 500 mJ / cm ² and then curing at 160 ° C. for 1 hour is measured with a dynamic viscoelasticity measuring apparatus (Corporation). As a result of measurement (sample size: length 20 mm, width 4 mm, film thickness 80 μm, temperature increase rate 5 ° C./min, tensile mode 10 Hz, automatic static load) using Rheology, DVE-V4), 400 MPa at 25 ° C. It was 1 MPa at 125 ° C. and 5 MPa at 260 ° C.

(2) Production of resin film for forming clad layer As binder polymer, 50 parts by mass of phenoxy resin (trade name: Phenotote YP-70, manufactured by Tohto Kasei Co., Ltd.), as a photopolymerizable compound, alicyclic diepoxycarboxy 50 parts by mass of a rate (trade name: KRM-2110, molecular weight: 252, manufactured by Asahi Denka Kogyo Co., Ltd.), as a photopolymerization initiator, triphenylsulfonium hexafluoroantimonate salt (trade name: SP-170, Asahi Denka Kogyo) (Made by Co., Ltd.) 4 parts by weight, 40 parts by weight of propylene glycol monomethyl ether acetate as an organic solvent was weighed into a wide-mouthed plastic bottle, using a mechanical stirrer, shaft and propeller, at a temperature of 25 ° C. and a rotational speed of 400 rpm, The mixture was stirred for 6 hours to prepare a clad layer forming resin varnish. After that, using a polyfluorone filter (trade name: PF020, manufactured by Advantech Toyo Co., Ltd.) with a pore size of 2 μm, it is filtered under pressure at a temperature of 25 ° C. and a pressure of 0.4 MPa, and further reduced in pressure using a vacuum pump and a bell jar. Degassed under reduced pressure for 15 minutes under the condition of a degree of 50 mmHg.

  The resin varnish for forming a clad layer obtained above was coated on a non-treated surface of a PET film (trade name: Cosmo Shine A4100, manufactured by Toyobo Co., Ltd., thickness: 50 μm) (Multicoater TM-MC , Manufactured by Hirano Tech Seed Co., Ltd.), dried at 80 ° C. for 10 minutes, then at 100 ° C. for 10 minutes, and then released as a protective film PET film (trade name: Purex A31, Teijin DuPont Films Ltd.) , Thickness: 25 μm) was pasted so that the release surface was on the resin side, and a resin film for forming a clad layer was obtained. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine. In this embodiment, the thickness after curing is 30 μm for the lower cladding layer and 80 μm for the upper cladding layer. Adjusted.

(3) Production of resin film for forming core layer As binder polymer, 26 parts by mass of phenoxy resin (trade name: Phenototo YP-70, manufactured by Tohto Kasei Co., Ltd.) and 9,9-bis [ 36 parts by mass of 4- (2-acryloyloxyethoxy) phenyl] fluorene (trade name: A-BPEF, manufactured by Shin-Nakamura Chemical Co., Ltd.), and bisphenol A type epoxy acrylate (trade name: EA-1020, Shin-Nakamura Chemical) 36 parts by mass of Kogyo Co., Ltd., and 2 parts of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (trade name: Irgacure 819, manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator Except for using 40 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent, the above The resin varnish for forming the core layer was prepared by the same method and conditions as in the example of producing the resin film for forming the cladding layer, and then pressure filtration and degassing under reduced pressure.

  The core layer-forming resin varnish obtained above is applied to the non-treated surface of a PET film (trade name: Cosmo Shine A1517, manufactured by Toyobo Co., Ltd., thickness: 16 μm) in the same manner as in the above production example. After coating and drying, a release PET film (trade name: A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) is attached as a protective film so that the release surface is on the resin side, and a resin film for forming a core layer Got. In this example, the gap of the coating machine was adjusted so that the film thickness after curing was 50 μm.

(4) Manufacture of optical waveguide composite substrate The protective film of the adhesive sheet prepared in (1) above is peeled off, and a silicon substrate with an oxide film (thickness 0.625 μm, oxide film 1 μm attached, manufactured by Mitsubishi Materials Corporation) ) At 60 ° C., 0.5 MPa, and a feed rate of 0.2 m / min so that the adhesive layer is in contact with the substrate. The thickness of the adhesive layer was 10 μm. Subsequently, the adhesive sheet is irradiated with ultraviolet rays (365 nm) at 250 mJ / cm ² from the support substrate side to reduce the adhesive force between the adhesive layer and the support substrate interface, and the support substrate is peeled off to perform adhesion. The agent layer was exposed.
Thereafter, the protective film of the clad layer forming resin film prepared in (2) above is peeled off so that the clad layer forming resin layer is in contact with the adhesive layer, and a roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd.). , HLM-1500), and roll laminated under the conditions of 80 ° C., 0.5 MPa, and feed rate of 0.5 m. Next, ultraviolet rays (wavelength 365 nm) were irradiated at 1 J / cm ² to peel off the supporting base material of the resin film for forming the cladding layer. Then, the lower clad layer 4 was formed by heat-processing at 80 degreeC for 10 minute (s).
Next, the core layer forming resin film is laminated on the lower clad layer 4 under the conditions of a pressure of 0.4 MPa, a temperature of 50 ° C., and a laminating speed of 0.2 m / min using the same roll laminator, and then a flat plate type A vacuum pressurization type laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) is used as a laminator. After vacuuming to 500 Pa or less, thermocompression bonding is performed under the conditions of pressure 0.4 MPa, temperature 50 ° C., pressurization time 30 seconds. Thus, the core layer 5 was formed (FIG. 1B
)reference).

Next, through a negative photomask with a width of 50 μm, the above ultraviolet exposure machine was irradiated with ultraviolet rays (wavelength 365 nm) of 0.6 J / cm ² (see FIG. 1C), and then exposed at 80 ° C. for 5 minutes. Heating was performed. Thereafter, the PET film as the support film was peeled off, and the core pattern 6 was developed using a developer (propylene glycol monomethyl ether acetate / N, N-dimethylacetamide = 8/2, mass ratio) (FIG. 1 (d )reference). Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (s).

Subsequently, the above-mentioned resin film for forming a clad layer was laminated under the same laminating conditions as those for laminating the lower clad layer. Further, after irradiation with ultraviolet rays (wavelength 365 nm) at 3 J / cm ² , the support substrate of the resin film for forming the clad layer is peeled off, and the upper clad layer 9 is formed by heat treatment at 180 ° C. for 1 hour. A composite substrate was manufactured. The results evaluated by the above method are shown in Table 1.

  When the refractive index of the core layer and the clad layer was measured with a prism coupler (Model 2010) manufactured by Metricon, the core layer was 1.584 and the clad layer was 1.550 at a wavelength of 830 nm. In addition, the propagation loss of the manufactured optical waveguide was measured by using a 850 nm surface emitting laser ((EXFO, FLS-300-01-VCL) as a light source, Advantest Co., Ltd., Q82214 as a light receiving sensor, and a cut-back method ( Measurement waveguide length: 10, 5, 3, 2 cm, incident fiber: GI-50 / 125 multimode fiber (NA = 0.20), output fiber: SI-114 / 125 (NA = 0.22)) However, it was 0.1 dB / cm.

Comparative Example 1
A silane coupling agent (manufactured by Toray Dow Corning Co., Ltd. [Z6040]) was applied on a silicon substrate similar to that used in Example 1 by spin coating at 500 rpm / 10 seconds, and further 1500 rpm / 30 seconds. The coating was performed under the conditions, and then heated on a hot plate at 120 ° C. for 3 minutes. On top of that, the optical waveguide composite substrate was manufactured by sequentially laminating by film lamination in the same manner as in Example 1. For spin coating, “1H-D2” manufactured by Mikasa Co., Ltd. was used.
The results evaluated in the same manner as in Example 1 are shown in Table 1.

Comparative Example 2
A flexible optical waveguide having a lower cladding layer, a core pattern, and an upper cladding layer using the same resin film for manufacturing a waveguide (a resin film for forming a cladding layer and a resin film for forming a core layer) as used in Example 1 Produced. Next, an adhesive layer was formed on the same silicon substrate as used in Example 1 by the same method as in Example 1 using the adhesive sheet produced in Example 1 (1). . The flexible optical waveguide was roll-laminated through the adhesive layer under the conditions of 80 ° C., 0.5 MPa, and feed rate of 0.5 m. Then, it heat-hardened at 180 degreeC for 1 hour, and manufactured the optical waveguide composite substrate. The results of evaluation in the same manner as in Example 1 are shown in Table 1.

As is clear from the comparison between Example 1 and Comparative Example 1, the optical waveguide composite substrate of the present invention can be obtained by a thermal cycle test by using a resin film for forming a cladding layer and a core layer in the optical waveguide manufacturing process. Even when heat shock is applied, the optical insertion loss does not change much, that is, an optical waveguide composite substrate having excellent heat resistance can be obtained. On the other hand, it can be seen that the optical waveguide composite substrate of Comparative Example 1 has an increased insertion loss due to peeling between the silicon substrate and the optical waveguide due to heat shock, and has low heat resistance.
Further, from the comparison between Example 1 and Comparative Example 2, it can be seen that the optical waveguide composite substrate of the present invention has no meandering in the core pattern.

  According to the manufacturing method of the present invention, an optical waveguide composite substrate in which no meandering is seen in the core pattern, excellent in heat resistance, and does not cause peeling of the optical waveguide from the silicon substrate or cracking of the silicon substrate due to thermal history. Can be efficiently manufactured. The optical waveguide composite substrate manufactured by the method of the present invention can be applied to a wide range of fields such as optical interconnection, especially when a very precise core pattern is required or a large-area optical waveguide composite substrate is required. It is effective for.

It is a schematic diagram which shows the manufacturing method of the optical waveguide composite substrate of this invention. It is a cross-sectional schematic diagram which shows the structure of the adhesive sheet in this invention. It is a cross-sectional schematic diagram which shows the structure of the resin film for lower clad layer formation in this invention. It is a cross-sectional schematic diagram which shows the structure of the resin film for core layer formation in this invention. It is a cross-sectional schematic diagram which shows the structure of the resin film for upper clad layer formation in this invention. It is a figure which shows the measuring method of the maximum displacement amount of a core pattern.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Optical waveguide composite substrate 2; Substrate 3; Adhesive layer 4, 4 '; Lower clad layer 5, 5'; Core layer 6; Core pattern 7; Photomask 8; Adhesive sheet 31; Adhesive layer 32; Support base material 33; Protective film 41; Lower clad layer forming resin film 42; Support base material 43; Protective film 51; Core layer forming resin film 52; 53; Protective film 91; Upper clad layer forming resin film 92; Support base material 93; Protective film

Claims (7)

  (A) A step of laminating a resin film for forming a lower clad layer on a substrate via an adhesive layer to form a clad layer, (B) a layer of a resin film for forming a core layer being laminated thereon (C) forming a core pattern by exposure and development, and (D) laminating a resin film for forming an upper clad layer on the core pattern to form an upper clad layer. A method for manufacturing a substrate. 2. The method for producing an optical waveguide composite substrate according to claim 1, wherein a storage elastic modulus at 125 ° C. measured under the following conditions of the adhesive composition constituting the adhesive layer is 10 MPa or less.
Storage elastic modulus measurement conditions: The test piece has a length of 20 mm, a width of 4 mm, and a film thickness of 80 μm, a temperature increase rate of 5 ° C./min, a tensile mode, a vibration frequency of 10 Hz, and an automatic static load.   The adhesive composition contains, as a main component, at least one adhesive component selected from a compound having two or more epoxy groups in a molecule and a compound having an ethylenically unsaturated group in the molecule. A method for manufacturing an optical waveguide composite substrate according to claim 2.   The adhesive composition comprises (a) a high molecular weight component having a functional group-containing weight average molecular weight of 100,000 or more, (b) an epoxy resin, (c) a phenolic epoxy resin curing agent, and (d) ultraviolet irradiation. The photoreactive monomer whose Tg of the hardened | cured material obtained by this is 250 degreeC or more, (e) The light guide of Claim 2 or 3 which contains the photoinitiator which generate | occur | produces a base and a radical by ultraviolet irradiation with a wavelength of 200-450 nm. A method for manufacturing a waveguide composite substrate.   (A) The high molecular weight component having a weight average molecular weight including a functional group of 100,000 or more is a glycidyl group-containing (meth) acrylic copolymer containing 0.5 to 6% by mass of a glycidyl group-containing repeating unit. The manufacturing method of the optical-waveguide composite board | substrate of description.   (A) For component 100 parts by mass, component (b) 5 to 250 parts by mass, component (d) 5 to 100 parts by mass, component (e) 0.1 to 20 parts by mass, and component (c) ( The method for producing an optical waveguide composite substrate according to claim 4 or 5, wherein the equivalent ratio of phenolic hydroxyl groups per epoxy group of the epoxy resin as component b) is in the range of 0.5 to 1.5.   The method for producing an optical waveguide composite substrate according to any one of claims 1 to 6, wherein the adhesive layer is formed by laminating an adhesive sheet comprising an adhesive composition and a supporting base material.

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