JP2011221288A - Method for manufacturing light waveguide and photo-electrical composite substrate, and light waveguide and photo-electrical composite substrate obtained by the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a light waveguide or a photo-electrical composite substrate capable of obtaining a light waveguide, whose core pattern is hardly affected by the difference of a material of a base material under a lower cladding layer and a reflection caused by the irregularities of the base material and scattered light, when the core pattern of the light waveguide is formed, and which reduces a light transmission loss and has little variations of the light transmission loss; and the light waveguide and the photo-electrical composite substrate obtained by the method.SOLUTION: The method for manufacturing the light waveguide and the photo-electrical composite substrate is characterized by applying light emission properties to the lower cladding layer and obtaining such a wavelength that a light emission wavelength contributes to curing of a core, so that the core pattern is exposed by using not only an ultraviolet light and a short wave visible light having high directivity from an exposure light source but also light emission having low directivity from the lower cladding layer, when the core pattern is exposed. The light waveguide and the photo-electrical composite substrate are obtained by the method.

Description

  In the present invention, when forming a core pattern of an optical waveguide, the core pattern is not easily affected by the difference in the material of the base material under the lower clad layer or the unevenness of the base material, and the light propagation loss is reduced. In addition, the present invention relates to an optical waveguide or a photoelectric composite substrate manufacturing method capable of obtaining an optical waveguide with little variation in the light propagation loss, and an optical waveguide and an photoelectric composite substrate obtained thereby.

  With the increase in information capacity, development of an optical interconnection technology that uses optical signals not only for communication fields such as trunk lines and access systems but also for information processing in routers and servers is underway. Specifically, in order to use light for short-distance signal transmission between boards in a router or a server device or in a board, an opto-electric composite board in which an optical transmission path is combined with an electric wiring board has been developed. As the optical transmission line, it is desirable to use an optical waveguide that has a higher degree of freedom of wiring and can be densified than an optical fiber, and among them, an optical waveguide that uses a polymer material that is excellent in processability and economy. Promising.

As a manufacturing method of this optical waveguide, for example, as described in Patent Document 1, after forming an optical waveguide on a support, the support is peeled off and taken out as an optical waveguide sheet. Bonded and used as a photoelectric composite substrate.
Further, as described in Patent Document 2, a method is known in which a lower clad layer, a core pattern, and an upper clad layer are formed on an electric wiring board to form a photoelectric composite substrate. If both the optical waveguide of Patent Document 1 and the optoelectric composite substrate of Patent Document 2 have irregularities in the carrier film or base material of the lower clad layer resin, the core width is unevenly formed during the core pattern exposure, and the increase in light propagation loss, This led to variations in optical propagation loss.
In addition, as described in Patent Document 3, a method of imparting fluorescence or phosphorescence to the cladding layer is known, but this method is used to improve the visibility of the core pattern, There was no improvement in the light propagation loss, and after the introduction, when compared before and after the introduction of the fluorescent agent, the loss was lower than before the introduction.

JP 2008-122908 A JP 2004-341454 A JP-A-8-75938

  The present invention has been made in order to solve the above-described problems, and when forming a core pattern of an optical waveguide, the core pattern is different in the material of the base material under the lower clad layer and reflected and scattered light due to the unevenness of the base material. Optical waveguide or optoelectric composite substrate manufacturing method capable of obtaining an optical waveguide that is less susceptible to influence and has low optical propagation loss and little variation in optical propagation loss, and optical waveguide and photoelectricity obtained thereby An object is to provide a composite substrate.

As a result of intensive studies, the inventors of the present invention have given directivity from the exposure light source during the core pattern exposure by providing the lower cladding layer with luminescence and making the emission wavelength a wavelength that contributes to the curing of the core. It was found that the above object was achieved by exposing the core pattern using not only high ultraviolet light and short-wave visible light but also light emission with low directivity from the lower cladding layer, and the present invention was completed. It was.
That is, the present invention
(1) In the optical waveguide manufacturing method including the step (A) of photocuring the core layer laminated on the lower clad layer by exposure to form a core pattern, the lower clad layer has a feature of emitting light by the exposure. And the core pattern is exposed by direct light from an exposure light source and light emission from the lower cladding layer.
(2) The method for manufacturing an optical waveguide according to (1), including a step (B) of removing the unexposed core layer after the step (A).
(3) The method for manufacturing an optical waveguide according to (1) or (2), including a step (C) of laminating an upper clad from the core pattern side,
(4) An optical waveguide manufactured by any one of the methods (1) to (3),
(5) The optical waveguide according to (4), having a core pattern exposed by light emission from the lower clad layer on a side surface of the core pattern,
(6) The optical waveguide according to (4) or (5), wherein the optical waveguide is an optical waveguide with a mirror,
(7) In the method for manufacturing an optical waveguide according to any one of (1) to (3), before the step (A), a step (D) of laminating the lower clad layer on the electric wiring board is further performed. A method for producing an optoelectric composite substrate,
(8) In the step (D), the electrical wiring board and the lower clad layer are laminated through at least one adhesive layer or more, wherein the photoelectric composite substrate according to (7) is manufactured Method,
(9) A photoelectric composite substrate manufactured by the method of (7) or (8),
(10) A photoelectric composite substrate obtained by bonding the optical waveguide according to (4) or (5) and an electric wiring board through one or more adhesive layers,
(11) The photoelectric composite substrate according to (9) or (10), wherein the photoelectric composite substrate is a photoelectric composite substrate with a mirror.

  According to the method for manufacturing an optical waveguide and an optoelectric composite substrate of the present invention, when the core pattern of the optical waveguide is formed, the core pattern is reflected and scattered light due to the difference in material of the base material under the lower cladding layer and the unevenness of the base material. Thus, it is possible to obtain an optical waveguide and an optical / electrical composite substrate that are less susceptible to the influence of the above, reduce the optical propagation loss, and reduce variations in the optical propagation loss.

It is a figure explaining an example of the manufacturing method of the optical waveguide of this invention. It is a figure explaining an example of the manufacturing method of the photoelectric composite board | substrate of this invention. It is a figure explaining another example of the manufacturing method of the photoelectric composite board | substrate of this invention. It is a figure explaining an example of the core pattern sectional view formed by the manufacturing method of the optical waveguide and photoelectric composite board of the present invention. It is a figure explaining the other example of the core pattern sectional drawing formed by the manufacturing method of the optical waveguide and photoelectric composite board | substrate of this invention. It is a figure explaining the other example of the core pattern sectional drawing formed by the manufacturing method of the optical waveguide and photoelectric composite board | substrate of this invention. It is a figure explaining an example of the manufacturing method of the conventional optical waveguide, and the core pattern sectional drawing formed of the photoelectric composite board | substrate.

  An optical waveguide 7 manufactured according to the present invention uses a lower cladding layer 1 that emits light with an exposure light source wavelength as the lower cladding layer 1, forms a core layer 2 on the lower cladding layer 1, direct light from the exposure light source, The optical waveguide 7 or the photoelectric composite substrate 8 that forms the core pattern 21 by the indirect light from the emitted lower clad layer 1, and after the core pattern 21 is further exposed, the uncured core layer 2 is developed and removed, The upper clad layer 3 is laminated from the core pattern 21 forming surface. For example, as shown in FIG. 1D, an optical waveguide 7 in which a core pattern 21 and an upper cladding layer 3 are sequentially laminated on the lower cladding layer 1, or as shown in FIG. This is an optoelectric composite substrate 8 in which a lower clad layer 1, a core pattern 21, and an upper clad layer 3 are laminated on an electric wiring board 5 in this order. The lower cladding layer 1 may emit light at an exposure wavelength that has passed through the core pattern.

  4 to 6 show the cross-sectional shape of the core pattern 21 obtained by the method for manufacturing the optical waveguide and the photoelectric composite substrate of the present invention, and FIG. 7 shows the cross-sectional shape of the core pattern 21 formed by the conventional method. Here, the cross-sectional shape means a cross-sectional shape of the core pattern 21 in a direction perpendicular to the base material, the electric wiring board, and the clad layer forming film lamination surface. The cross-sectional shape of the core pattern 21 obtained by the method for manufacturing an optical waveguide and an optoelectric composite substrate of the present invention has a core pattern 212 exposed by light emission from the lower cladding layer 1 on the side surface of the core. This is because when the core pattern 21 is exposed, the core pattern 212 is exposed by isotropic light emission from the core pattern 21, the boundary surface of the lower cladding layer 1, and the lower cladding layer 1. 4 to 6 are different depending on the light emission intensity from the light-emitting lower cladding layer 1 and the exposure amount of the core pattern 21, but FIG. 5 is preferable to FIG. 4, and FIG. 6 is more preferable than FIG. Further preferred. Here, the core pattern 211 is exposed mainly by direct light from an exposure light source, and the core pattern 212 is exposed mainly by light emission from the lower cladding layer.

(Optical waveguide manufacturing method)
Hereafter, the manufacturing method of the optical waveguide of this invention is explained in full detail (refer FIG. 1).
First, as shown in FIGS. 1A and 1B, a core layer 2 is formed on a light-emitting lower cladding layer 1, and a core pattern 21 is formed by performing exposure and development. Can be manufactured by laminating.
The method for forming the lower clad layer 1 is not particularly limited, and may be a known method. For example, after the material for forming the lower clad layer 1 is applied onto the carrier film 4 by spin coating or the like and prebaked. The thin film can be formed by irradiating ultraviolet rays. Also, the formation of the core pattern 21 is not particularly limited. For example, the core layer 2 having a refractive index higher than that of the lower cladding layer 1 may be formed on the lower cladding layer 1 and the core pattern 21 may be formed by etching. The formation method of the upper cladding layer 3 is not particularly limited, and may be formed by the same method as that of the lower cladding layer 1, for example.
From the viewpoint of adhesion to the core layer 2, the lower cladding layer 1 is preferably flat without a step on the surface on the core layer 2 lamination side. Moreover, the surface flatness of the lower clad layer 1 can be ensured by using the resin film for forming the clad layer.

(Photoelectric composite substrate manufacturing method)
Hereafter, the manufacturing method of the photoelectric composite board | substrate of this invention is explained in full detail (refer FIG. 1).
First, as shown in FIGS. 2C and 2D, the lower clad layer 1 is provided on the electric wiring board 5 on which the circuit is formed, the core pattern 21 is formed thereon, and the upper clad layer 3 is further formed. Laminate.
The formation method of the lower clad layer 1, the core pattern 21, and the upper clad layer 3 is not particularly limited, and may be a known method, and can be formed by the method shown in the method for manufacturing the optical waveguide 7 described above. When there is no adhesive force between the electric wiring board 5 and the lower cladding layer 1, an adhesive layer 6 may be sandwiched between the electric wiring board 5 and the lower cladding layer 1 as shown in FIG.
Alternatively, the optical waveguide 7 manufactured by the method described above for manufacturing the optical waveguide 7 and the electric wiring board 5 may be bonded together via the adhesive layer 6 to form the photoelectric composite substrate 8.

Hereinafter, each component of the photoelectric composite substrate will be described.
(Luminescent lower cladding layer)
When the lower clad layer 1 resin itself does not have sufficient light-emitting properties, it is preferable to add a light-emitting additive, and the kind of the light-emitting additive is not particularly limited. Examples thereof include phosphorescent agents, coloring agents, phosphorescent agents, luminescent photosensitizers, luminescent photopolymerization initiators, photo-converting ultraviolet absorbers, and combinations of two or more thereof. In particular, when an ultraviolet lamp is used as the exposure light source of the core pattern 21, a fluorescent agent, a phosphorescent agent, a phosphorescent agent, a luminescent photosensitizer, a luminescent photopolymerization initiator, a light conversion type ultraviolet absorber, and It is more preferable to use a combination of two or more of them. A plurality of types of additives having different absorption wavelengths may be combined for adjusting the absorption wavelength and the emission wavelength. The addition amount of the additive is an amount that does not affect the light propagation loss, and is appropriately changed according to the exposure amount necessary for forming the core pattern 21, the thickness and transmittance of the core layer 2, and the emission intensity of the lower cladding layer 1. Good.

(Emission wavelength)
The emission wavelength from the lower cladding layer 1 is not particularly limited, and the lower cladding layer 1 only needs to emit light depending on the wavelength of the light source of the exposure machine used when exposing the core pattern 21. The emission wavelength from the lower cladding layer 1 is Any wavelength that contributes to the curing of the core pattern 21 may be used. The method for confirming whether or not the emission wavelength contributes to the curing of the core pattern 21 is to compare the absorption spectrum of the photocuring initiator or photosensitizer contained in the resin for the core layer 2 with the emission spectrum from the lower cladding layer 1. Then, it is sufficient to confirm that there are overlapping wavelengths. As another confirmation method, the core layer 21 formed on the lower clad layer 1 containing the luminescent additive and the lower clad layer 1 not containing the luminescent additive is respectively formed under the same exposure conditions to form the luminescent additive. It is confirmed that the width of the core pattern 21 on the lower clad layer 1 side of the core pattern 21 formed on the lower clad layer 1 containing no is longer than the width of the core pattern 21 formed on the lower clad layer 1 containing no light-emitting additive. It is sufficient to confirm that the cross-sectional shape of the core pattern 21 is one of the structures shown in FIGS. Further, the emission intensity is not particularly limited, but may be adjusted according to the amount of the additive introduced into the lower clad layer 1 as long as the light propagation loss and the cross-sectional shape of the core pattern 21 are not adversely affected.

(Adhesive layer)
In order to secure the adhesive force between the electric wiring board 5 and the lower cladding layer 1, the type of the adhesive layer 6 introduced between the electric wiring board 5 and the lower cladding layer 1 is not particularly limited, but double-sided tape, UV or heat Preferable examples include various adhesives used for curable adhesives, prepregs, build-up materials, and electrical wiring board manufacturing applications.
In addition, an adhesive or adhesive film having a high transmittance is required for adhesion of a portion through which an optical signal is transmitted, and the material of the adhesive or adhesive film is not particularly limited. It is more preferable to use a resin material for use and an adhesive film described in (PCT / JP2008 / 05465).
The method for forming the adhesive layer 6 is not particularly limited, but the resin for forming the adhesive layer 6 may be applied onto the electric wiring board 5 or the optical waveguide 7 by spin coating or the like, and processed into a film shape in advance. The adhesive layer 6 may be bonded with a laminator or the like.
Although the thickness of the contact bonding layer 6 is not specifically limited, It is preferable that they are 0.1 micrometer-3.0 mm, and it is more preferable that they are 1 micrometer-100 micrometers. This is because when the thickness is 1 μm or more, a sufficient adhesive force between the electric wiring board 5 and the lower cladding layer 1 or the optical waveguide 7 can be expected, and when the thickness is 100 μm or less, a thin photoelectric composite substrate 8 can be obtained.

(Electric wiring board)
The electric wiring board 5 used in the present invention is not particularly limited, and various electric wiring boards 5 used for an optoelectric composite substrate can be used. For example, an electric wiring is formed on a substrate of an insulating layer. It may be a plate material made of only a metal layer or an insulating layer. Further, the above wiring board may be multilayered. When electrical wiring is formed and there is unevenness in the wiring, planarization may be performed using a resin for embedding or an adhesive layer 6. The electric wiring board 5 may be a rigid substrate or a flexible substrate.

(Carrier film)
The type of carrier film 4 is not particularly limited. For example, an FR-4 substrate, a polyimide substrate, a semiconductor substrate, a silicon substrate, a glass substrate, or the like can be used. However, it may be made of an inflexible hard material.
Further, by using a flexible material for the carrier film 4, flexibility can be imparted to the optical waveguide 7. The material of the material having flexibility is not particularly limited, but from the viewpoint of having flexibility and toughness, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polyamide, polycarbonate, Preferable examples include polyphenylene ether, polyether sulfide, polyarylate, liquid crystal polymer, polysulfone, polyether sulfone, polyether ether ketone, polyether imide, polyamide imide, and polyimide.
The thickness of the carrier film 4 may be appropriately changed depending on the intended flexibility, but is preferably 5 μm to 10 mm, and more preferably 5 μm to 250 μm. When the thickness of the film is 5 μm or more, there is an advantage that toughness is easily obtained, and when it is 250 μm or less, sufficient flexibility is obtained. The carrier film 4 may be removed after or during the production of the optical waveguide 7 and the photoelectric composite substrate 8.

(Lower cladding layer and upper cladding layer)
Hereinafter, the lower clad layer 1 and the upper clad layer 3 used in the present invention will be described. As the lower clad layer 1 and the upper clad layer 3, a clad layer forming resin or a clad layer forming resin film can be used.

  The clad layer forming resin used in the present invention is not particularly limited as long as it is a resin composition that has a lower refractive index than that of the core layer 2 and is cured by light or heat. A thermosetting resin composition or a photosensitive resin composition is used. Can be preferably used. More preferably, 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 resin composition used for the clad layer forming resin may be the same or different in the components contained in the resin composition in the lower clad layer 1 and the upper clad layer 3. The refractive indexes may be the same or different.

  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, etc., or derivatives thereof. These base polymers may be used alone or in combination of two or more. Of the base polymers exemplified above, from the viewpoint of high heat resistance, the main chain preferably has an aromatic skeleton, 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. Further, compatibility with the photopolymerizable compound (B) described in detail later is important for ensuring the transparency of the resin for forming the cladding layer. From this point, the phenoxy resin and the (meth) acrylic resin are used. Is preferred. Here, (meth) acrylic resin means acrylic resin and methacrylic resin.

  Among phenoxy resins, those containing bisphenol A, bisphenol A type epoxy compounds or derivatives thereof, and bisphenol F, bisphenol F type epoxy compounds or derivatives thereof as a constituent unit of the copolymer component are heat resistant, adhesive and soluble. It is preferable because of its excellent properties. 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.

  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).

Next, (B) the photopolymerizable compound is not particularly limited as long as it is polymerized by irradiation with light such as ultraviolet rays, and the compound having an ethylenically unsaturated group in the molecule or two or more in the molecule. Examples thereof include compounds having an epoxy group.
Examples of the compound having an ethylenically unsaturated group in the molecule include (meth) acrylate, vinylidene halide, vinyl ether, vinyl pyridine, vinyl phenol, etc., among these, from the viewpoint of transparency and heat resistance, (Meth) acrylate is preferred.
As the (meth) acrylate, any of monofunctional, bifunctional, trifunctional or higher polyfunctional ones can be used. Here, (meth) acrylate means acrylate and methacrylate.
Examples of the compound having two or more epoxy groups in the molecule include bifunctional or polyfunctional aromatic glycidyl ethers such as bisphenol A type epoxy resins, bifunctional or polyfunctional aliphatic glycidyl ethers such as polyethylene glycol type epoxy resins, and water. Bifunctional alicyclic glycidyl ether such as bisphenol A type epoxy resin, bifunctional aromatic glycidyl ester such as diglycidyl phthalate, bifunctional alicyclic glycidyl ester such as tetrahydrophthalic acid diglycidyl ester, N, N- Bifunctional or polyfunctional aromatic glycidylamine such as diglycidylaniline, bifunctional alicyclic epoxy resin such as alicyclic diepoxycarboxylate, bifunctional heterocyclic epoxy resin, polyfunctional heterocyclic epoxy resin, bifunctional Or polyfunctional silicon-containing epoxy resin It is. These (B) photopolymerizable compounds can be used alone or in combination of two or more.

  Next, the photopolymerization initiator of component (C) is not particularly limited. For example, as an initiator when an epoxy compound is used as component (B), aryldiazonium salt, diaryliodonium salt, triarylsulfonium salt, triallyl Examples include selenonium salts, dialkylphenazylsulfonium salts, dialkyl-4-hydroxyphenylsulfonium salts, and sulfonate esters. When a luminescent photopolymerization initiator is used, the luminescent lower cladding layer 1 can be obtained.

Moreover, as an initiator in the case of using a compound having an ethylenically unsaturated group in the molecule as the component (B), aromatic ketones such as benzophenone, quinones such as 2-ethylanthraquinone, benzoin ethers such as benzoin methyl ether Compounds, benzoin compounds such as benzoin, benzyl derivatives such as benzyldimethyl ketal, 2,4,5-triarylimidazole dimers such as 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- Benzimidazoles such as mercaptobenzimidazole, phosphine oxides such as bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, acridine derivatives such as 9-phenylacridine, N-phenylglycine, N-phenylglycine derivatives , Coumarin compound And the like. Moreover, you may combine a thioxanthone type compound and a tertiary amine compound like the combination of diethyl thioxanthone and dimethylaminobenzoic acid. Of these compounds, aromatic ketones and phosphine oxides are preferred from the viewpoint of improving the transparency of the core layer and the cladding layer.
These (C) photopolymerization initiators can be used alone or in combination of two or more.

(A) It is preferable that the compounding quantity of a base polymer shall be 5-80 mass% with respect to the total amount of (A) component and (B) component. Moreover, it is preferable that the compounding quantity of (B) photopolymerizable compound shall be 95-20 mass% with respect to the total amount of (A) and (B) component.
As a blending amount of the component (A) and the component (B), when the component (A) is 5% by mass or more and the component (B) is 95% by mass or less, the resin composition is easily formed into a film. Can do. On the other hand, when the component (A) is 80% by mass or less and the component (B) is 20% by mass or more, the (A) base polymer can be easily entangled and cured, and the optical waveguide 7 is formed. Furthermore, the pattern forming property is improved and the photocuring reaction proceeds sufficiently. From the above viewpoint, the blending amount of the component (A) and the component (B) is more preferably 10 to 85% by mass of the component (A) and 90 to 15% by mass of the component (B), and 20 to 70 of the component (A). More preferably, the content is 80% by mass and the component (B) is 80 to 30% by mass.
(C) It is preferable that the compounding quantity of a photoinitiator shall be 0.1-10 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component. When the blending amount is 0.1 parts by mass or more, the photosensitivity is sufficient, while when it is 10 parts by mass or less, the absorption in the surface layer of the photosensitive resin composition does not increase during exposure, and the internal Is sufficiently cured. Furthermore, when used as the optical waveguide 7, it is preferable that the light propagation loss does not increase due to the light absorption effect of the polymerization initiator itself. From the above viewpoint, the blending amount of the (C) photopolymerization initiator is more preferably 0.2 to 5 parts by mass.
In addition, if necessary, in the cladding layer forming resin, an antioxidant, an anti-yellowing agent, an ultraviolet absorber, a visible light absorber, a colorant, a plasticizer, a stabilizer, a filler, etc. You may add what is called an additive in the ratio which does not have a bad influence on the effect of this invention. Further, if the additive has a light emitting property, the light emitting lower cladding layer 1 can be obtained.

In the present invention, the method for forming the clad layer is not particularly limited. For example, the clad layer may be formed by applying a clad layer forming resin or laminating a clad layer forming resin film.
In the case of application, the method is not limited. For example, the resin composition containing the components (A) to (C) may be applied by a conventional method.
Moreover, the resin film for clad layer formation used for a lamination can be easily manufactured by melt | dissolving the said resin composition in a solvent, apply | coating it to a support body film, and removing a solvent, for example.

The material of the carrier film 4 used in the production process of the resin film for forming the clad layer is not particularly limited, and various materials can be used. From the viewpoint of flexibility and toughness as the carrier film 4, those exemplified as the carrier film material described above can be cited in the same manner.
The thickness of the carrier film 4 may be appropriately changed depending on the intended flexibility, but is preferably 5 to 250 μm. If it is 5 μm or more, there is an advantage that toughness can be easily obtained, and if it is 250 μm or less, sufficient flexibility can be obtained.
The solvent used here is not particularly limited as long as it can dissolve the resin composition. For example, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylacetamide, propylene glycol monomethyl ether, propylene A solvent such as glycol monomethyl ether acetate, cyclohexanone, N-methyl-2-pyrrolidone, or a mixed solvent thereof can be used. The solid content concentration in the resin solution is preferably about 30 to 80% by mass.

  Regarding the thickness of the lower clad layer 1 and the upper clad layer 3 (hereinafter abbreviated as clad layers 1 and 3), the thickness after drying is preferably in the range of 5 to 500 μm. When the thickness is 5 μm or more, a clad thickness necessary for light confinement can be secured, and when the thickness is 500 μm or less, it is easy to control the film thickness uniformly. From the above viewpoint, the thickness of the cladding layers 4 and 6 is more preferably in the range of 10 to 100 μm.

  The thicknesses of the cladding layers 1 and 3 may be the same or different in the lower cladding layer 1 formed first and the upper cladding layer 3 for embedding the core pattern 21, but the core pattern 21 is embedded. Therefore, it is preferable that the thickness of the upper clad layer 3 is larger than the thickness of the core layer.

(Core layer forming resin and core layer forming resin film)
In the present invention, the method for forming the core layer 2 laminated on the lower cladding layer 1 in order to form the core pattern 21 is not particularly limited. For example, coating of the core layer forming resin or laminating of the core layer forming resin film is possible. It may be formed by.
As the resin for forming the core layer 2, a resin composition that is designed so that the core pattern 21 has a higher refractive index than the cladding layers 1 and 3 and can form the core pattern 21 by actinic rays can be used, and the lower cladding layer A photosensitive resin composition that is cured by the emission wavelength from 1 or a core layer forming resin containing a photopolymerization initiator that initiates polymerization by the emission wavelength from the lower cladding layer 1 is suitable. Specifically, it is preferable to use the same resin composition as that used in the clad layer forming resin.
In the case of application, the method is not limited, and the resin composition may be applied by a conventional method.

Hereinafter, the resin film for core layer formation used for lamination is explained in full detail.
The resin film for forming the core layer can be easily produced by dissolving the resin composition in a solvent, applying the resin composition onto the carrier film 4, and removing the solvent. The solvent used here is not particularly limited as long as it can dissolve the resin composition. For example, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, N, N-dimethyl A solvent such as acetamide, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, N-methyl-2-pyrrolidone, or a mixed solvent thereof can be used. It is preferable that the solid content concentration in the resin solution is usually 30 to 80% by mass.

  The thickness of the resin film for forming the core layer 2 is not particularly limited, and the thickness of the dried core layer is usually adjusted to be 10 to 100 μm. When the thickness of the film 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 / emitting after the optical waveguide is formed. In coupling with an element or an optical fiber, there is an advantage that coupling efficiency is improved. From the above viewpoint, the thickness of the film is preferably in the range of 30 to 70 μm.

The carrier film 4 used in the production process of the core layer forming resin is a carrier film 4 that supports the core layer forming resin, and the material thereof is not particularly limited. However, the film material described above in the section of (Carrier film) Are preferable. Moreover, polyesters, such as a polyethylene terephthalate, a polypropylene, polyethylene, etc. are mentioned suitably from the viewpoint that it is easy to peel the resin for forming the core layer 2 and has heat resistance and solvent resistance.
The thickness of the carrier film 4 is preferably 5 to 50 μm. When it is 5 μm or more, there is an advantage that the strength as the carrier film 4 can be easily obtained, and when it is 50 μm or less, there is an advantage that a gap with the mask at the time of pattern formation becomes small and a finer pattern can be formed. From the above viewpoint, the thickness of the carrier film 4 is more preferably in the range of 10 to 40 μm, and particularly preferably 15 to 30 μm.

  The optical waveguide 7 used in the present invention may be a multilayer optical waveguide in which a plurality of layers having the core pattern 21 and the cladding layers 1 and 3 are stacked.

  EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

Production Example 1 [Production of Resin Film for Adhesive Layer 6]
A resin film for the adhesive layer 6 described in PCT / JP2008 / 05465 was produced. That is, (a) YDCN-703 (trade name, manufactured by Toto Kasei Co., Ltd., cresol novolac type epoxy resin, epoxy equivalent 210) 55 parts by mass as an epoxy resin, (b) Millex XLC-LL (Mitsui Chemicals, Inc.) as a curing agent Product name, phenol resin, hydroxyl group equivalent 175, water absorption rate 1.8% by mass, heating weight reduction rate 4% at 350 ° C. 45% by mass, silane coupling agent NUC A-189 (trade name, manufactured by Nihon Unicar Co., Ltd.) 1.7 parts by weight of γ-mercaptopropyltrimethoxysilane) and 3.2 parts by weight of NUC A-1160 (trade name, γ-ureidopropyltriethoxysilane manufactured by Nihon Unicar Co., Ltd.), (d) Aerosil R972 (silica) as filler The surface is coated with dimethyldichlorosilane and hydrolyzed in a 400 ° C reactor. , A filler having an organic group such as a methyl group on its surface, Nippon Aerosil Co., Ltd., trade name, silica, average particle size 0.016 μm) 32 parts by mass, cyclohexanone is added to the mixture, and the mixture is further stirred. And kneaded for 90 minutes. 280 parts by mass of (c) acrylic rubber HTR-860P-3 (trade name, weight average molecular weight of 800,000 manufactured by Nagase ChemteX Corporation) containing 3% by mass of glycidyl acrylate or glycidyl methacrylate as a polymer compound, and (e ) Curazole 2PZ-CN (trade name, 1-cyanoethyl-2-phenylimidazole manufactured by Shikoku Kasei Kogyo Co., Ltd.) as a curing accelerator was added in an amount of 0.5 parts by mass, stirred and mixed, and vacuum degassed. This adhesive varnish was applied as a carrier film 4 on a 75 μm-thick polyethylene terephthalate (PET) film (trade name: Purex A31, Teijin DuPont Films Co., Ltd.) with a release treatment, and heated and dried at 140 ° C. for 5 minutes. Then, a 25 μm release treated PET film (Purex A31) was attached as a protective film so that the release surface was on the resin side to obtain a resin film for the adhesive layer 6.
Hereinafter, description will be made on the assumption that the resin film for the adhesive layer 6 is in a state immediately after peeling off the protective film immediately before use.

Example 1
(1) Production of optical waveguide [production of resin film for forming clad layer]
(A) As a base polymer, 48 parts by mass of phenoxy resin (trade name: Phenototo YP-70, manufactured by Toto Kasei Co., Ltd.), (B) As a photopolymerizable compound, alicyclic diepoxycarboxylate (trade name: KRM) -2110, molecular weight: 252, Asahi Denka Kogyo Co., Ltd.) 50 parts by mass, (C) As a photopolymerization initiator, triphenylsulfonium hexafluoroantimonate salt (trade name: SP-170, Asahi Denka Kogyo Co., Ltd.) 2 parts by mass, (D) 0.4 parts by mass as a luminescent agent (luminescent photosensitizer) (trade name: SP-100, manufactured by Asahi Denka Kogyo Co., Ltd.), 40 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent Weigh the part in a wide-mouthed plastic bottle and use a mechanical stirrer, shaft and propeller, at a temperature of 25 ° C. and a rotational speed of 400 rpm. In matter, and stirred for 6 hours to prepare a resin varnish A for forming a cladding layer. After that, using a polyflon filter (trade name: PF020, manufactured by Advantech Toyo Co., Ltd.) with a pore diameter of 2 μm, the mixture is filtered under pressure at a temperature of 25 ° C. and a pressure of 0.4 MPa, and further the degree of vacuum using a vacuum pump and a bell jar. Degassed under reduced pressure for 15 minutes under the condition of 50 mmHg.
The coating varnish A obtained above is applied to the corona-treated surface of the polyamide film (trade name “Mictron”, thickness 12 μm, manufactured by Toray Industries, Inc.) as the carrier film 4. -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 PET film (trade name: Purex A31, Teijin DuPont Film) Co., Ltd., thickness: 25 μm) was attached 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 cured film thickness is 25 μm for the lower cladding layer and 70 μm for the upper cladding layer. Adjusted.

[Production of resin film for core layer formation]
(A) As a base polymer, 26 parts by mass of phenoxy resin (trade name: Phenototo YP-70, manufactured by Toto Kasei Co., Ltd.), (B) 9,9-bis [4- (2-acryloyl) as a photopolymerizable compound Oxyethoxy) phenyl] fluorene (trade name: A-BPEF, Shin-Nakamura Chemical Co., Ltd.) 36 parts by mass, and bisphenol A type epoxy acrylate (trade name: EA-1020, Shin-Nakamura Chemical Co., Ltd.) 36 mass Parts, (C) 1 part by mass of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (trade name: Irgacure 819, manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator, and 1- [4 -(2-Hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (trade name: yl Cure 2959, manufactured by Ciba Specialty Chemicals) 1 part by weight, and using resin varnish B for forming a core layer under the same method and conditions as in the above production example, except that 40 parts by weight of propylene glycol monomethyl ether acetate was used as the organic solvent Prepared. Thereafter, pressure filtration and degassing under reduced pressure were performed under the same method and conditions as in the above production example.
The core layer-forming resin varnish B 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: PUREX A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) is applied as a protective film so that the release surface is on the resin side, and a core layer forming resin A film was obtained. In this example, the gap of the coating machine was adjusted so that the film thickness after curing was 50 μm.

[Confirmation of core pattern hardening by light emission from lower clad layer]
It was confirmed whether the emission wavelength from the lower cladding layer and the wavelength contributing to the hardening of the core layer overlap. First, since a high-pressure mercury lamp is used as an exposure light source for exposing the core pattern, a cladding layer forming resin when photoexcited by i-line (365 nm), h-line (405 nm), and g-line (436 nm), which are mercury emission lines, is used. The emission spectrum of the luminescent photosensitizer (D) used in the production of the film (trade name: SP-100, manufactured by Asahi Denka Kogyo Co., Ltd.) was measured. As a result, light emission in the 400 nm to 600 nm region was confirmed in all emission lines. Next, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (trade name: Irgacure 819, Ciba Specialty Chemicals) which is a photopolymerization initiator (C) used in the production of the core layer forming resin film Absorption spectrum was measured. As a result, it was confirmed that a wavelength in the range of 440 nm or less was absorbed. From the above results, it was confirmed that the emission wavelength from the lower clad layer of 400 to 440 nm was effective in curing the core pattern.

[Production of optical waveguide]
Ultraviolet rays (wavelength 365 nm) with an ultraviolet exposure machine (trade name: EXM-1172, manufactured by Oak Manufacturing Co., Ltd.) using a high-pressure mercury lamp as a light source from the PET film surface side which is the protective film of the lower clad layer 1 obtained above. ) Was irradiated at 1.5 J / cm ² , and then the protective film was peeled off and dried at 80 ° C. for 12 minutes (see FIG. 1A).
Next, the resin surface of the resin film for forming the core layer 2 is formed on the lower clad layer 1 using a roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd., trade name: HLM-1500), pressure 0.4 MPa, temperature 50 ° C., laminating speed. Lamination was performed under the condition of 0.2 m / min. Next, through a negative photomask with a width of 50 μm, ultraviolet rays (wavelength 365 nm) are irradiated with 0.5 J / cm ² with the above-described ultraviolet exposure machine to form a core pattern 21, followed by heating after exposure at 80 ° C. for 12 minutes. went. Thereafter, the PET film which is the carrier film 4 of the resin film for forming the core layer 2 is peeled off and cured using a developer (propylene glycol monomethyl ether acetate / N, N-dimethylacetamide = 7/3, mass ratio). Unexposed core layer 2 was removed. Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (refer FIG.1 (b)).
Next, the resin film for forming the upper clad layer 3 is vacuum pressure laminator (trade name: MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.), pressure 0.4 MPa, temperature 50 ° C., pressurization time 30 seconds. Lamination was performed under the following conditions. Next, the upper clad layer 3 is photocured by irradiating ultraviolet rays (wavelength 365 nm) with 3.0 J / cm ² with the ultraviolet exposure machine, and then heat-treated at 160 ° C. for 1 hour, whereby the upper clad layer 3 is It hardened | cured (refer FIG.1 (c)). Thereafter, in order to lower the adhesive strength between the clad resin and the polyamideimide film, it is left for 8 hours in an environment of a temperature of 85 ° C. and a humidity of 85%, and the polyamide film as the carrier film 4 of the resin film for forming the lower clad layer 1 The polyamide film which is the carrier film 4 of the resin film for forming the upper clad layer 3 was peeled off to produce an optical waveguide 7 (see FIG. 1 (d) -1).

  The light propagation loss of the five optical waveguides 7 produced in this way is obtained by using a 855 nm LED (manufactured by Advantest, product name: Q81201) and a light receiving sensor (manufactured by Advantest, product name: Q82214) as a light source. Used, cutback method (measurement waveguide length 5, 3, 2 cm, incident fiber; GI-50 / 125 multimode fiber (NA = 0.20), outgoing fiber; SI-114 / 125 (NA = 0.22) , Incident light; effective core diameter 26 μm), the results shown in Table 1 were obtained.

A 45 ° mirror portion 12 was formed from the upper clad layer 3 side of the obtained optical waveguide 7 using a dicing saw (DAC552, manufactured by DISCO Corporation) (see FIG. 1 (d) -2; FIG. 1 (d) ) Schematic diagram of a plane perpendicular to the plane of −1).
Next, in order to observe the cross-sectional shape, the optical waveguide 7 was cut off by 2 mm using the above dicing saw, and the cross-sectional shape was confirmed using a 200 × microscope. As a result, the cross-sectional shape was FIG. The length of the upper side of the upper clad layer 3 side of the core cross section was 48 μm, and the length of the lower side of the lower clad layer 1 side was 50.2 μm.

Example 2
In Example 1, an optical waveguide was manufactured in the same manner except that the exposure amount of the core pattern 21 was irradiated at 0.9 J / cm ² .
When the optical propagation loss of the optical waveguide 7 thus produced was measured by the same method as in Example 1, the results shown in Table 2 were obtained.

  In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the upper clad layer 3 side of the core cross section was 50.1 μm, and the length of the lower side of the lower clad layer 1 side was 52.1 μm.

Example 3
In Example 1, an optical waveguide was manufactured in the same manner except that the exposure amount of the core pattern 21 was irradiated at 1.2 J / cm ² .
When the optical propagation loss of the optical waveguide 7 thus manufactured was measured by the same method as in Example 1, the results shown in Table 3 were obtained.

  In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the core cross section on the upper clad layer 3 side was 52.4 μm, and the length of the lower side of the lower clad layer 1 side was 55.3 μm.

Example 4
In Example 1, the carrier film 4 of the lower clad layer 1 and the upper clad layer 3 was changed to a release PET film (trade name: Purex A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) instead of the polyamide film. A resin film for forming a lower cladding layer was used in the same manner except for the above.

(Preparation of electrical wiring board: Electric wiring formation by subtractive method)
Photosensitive dry film resist (trade name: Photec, on the copper foil surface of polyimide with single-sided copper foil (trade name: Iupicel N, manufactured by Ube Nitto Kasei Kogyo Co., Ltd., copper foil thickness: 9 μm, polyimide thickness 12.5 μm) Hitachi Chemical Co., Ltd., thickness: 25 μm) is applied using a roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.) under the conditions of pressure 0.4 MPa, temperature 110 ° C., laminating speed 0.4 m / min. Next, ultraviolet light (wavelength 365 nm) was irradiated from the photosensitive dry film resist side through a negative photomask with a width of 50 μm with an ultraviolet exposure machine (manufactured by Oak Manufacturing Co., Ltd., EXM-1172), and exposed to 120 mJ / cm ^2. Part of the photosensitive dry film resist was removed with a dilute solution of 0.1-5 wt% sodium carbonate at 35 ° C. Thereafter, using a ferric chloride solution, the exposed copper foil of the photosensitive dry film resist was removed by etching, and exposure was performed using a 1-10 wt% sodium hydroxide aqueous solution at 35 ° C. A portion of the photosensitive dry film resist was removed to form an electrical wiring board 5 having 110 mm straight electrical wiring (see FIG. 2A).

(Formation of insulating protective layer)
Next, a coverlay film (trade name: Nikaflex CISG, manufactured by Nikkan Kogyo Co., Ltd., polyimide thickness: 12.5 μm, adhesive thickness: 15 μm), pressure 4.0 MPa, temperature 160 ° C., pressurization time 90 minutes The film was vacuum-pressed under these conditions to provide an insulating protective layer 11 for protecting the electrical wiring 5 (see FIG. 2B).

(Formation of insulating protective layer)
Next, the adhesive surface of the adhesive layer 6 described in PCT / JP2008 / 05465 obtained in Production Example 1 is applied to the polyimide surface of the electrical wiring board 5 with a roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd., trade name: HLM-1500). ) Under the conditions of a pressure of 0.4 MPa, a temperature of 50 ° C., and a laminating speed of 0.2 m / min.

Next, the release PET film (Purex A31), which is a protective film for the resin film for forming the light-emitting lower clad layer 1 obtained above, is peeled off, and on the polyimide surface of the electrical wiring board 5 obtained above. Affixed under the same laminating conditions as described above, irradiated with ultraviolet rays (wavelength 365 nm) from the resin side with an ultraviolet exposure machine (trade name: EXM-1172, manufactured by Oak Manufacturing Co., Ltd.) at 1.5 J / cm ² , The release PET film (trade name: PUREX A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm), which is the carrier film 4, is peeled off and heat-treated at 80 ° C. for 10 minutes, whereby the luminescent lower cladding layer 1 is formed. It formed (refer FIG.2 (c)).
Next, the core layer-forming resin film was laminated on the lower clad layer 1 under the same laminating conditions as above to form the core layer 2.

Next, ultraviolet rays (wavelength 365 nm) were irradiated with 0.6 J / cm ² with a UV photomask through a negative photomask having a width of 50 μm, followed by heating at 80 ° C. for 5 minutes. Thereafter, the PET film as the carrier film 4 was peeled off, and the core pattern 21 was developed using a developer (propylene glycol monomethyl ether acetate / N, N-dimethylacetamide = 7/3, mass ratio). Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (refer FIG.2 (d)).

Next, a vacuum pressure laminator (manufactured by Meiki Seisakusho Co., Ltd., trade name: MVLP-500) is used as a flat plate laminator, and the resin film for forming a clad layer is evacuated to 500 Pa or less as an upper clad layer 3. Thermocompression bonding was performed under the conditions of 0.4 MPa, a temperature of 50 ° C., and a pressing time of 30 seconds.
Further, after irradiation with ultraviolet rays (wavelength 365 nm) at 3 J / cm ² , the release PET film (trade name: Purex A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) as the carrier film 4 is peeled off, and 1 at 180 ° C. The upper clad layer 3 was cured by heat treatment for a period of time to produce a photoelectric composite substrate 8 (see FIG. 2 (e) -1).

  The optical propagation loss of the thus produced photoelectric composite substrate was measured using an 855 nm LED (trade name: Q81201, manufactured by Advantest Corporation) and a light receiving sensor (trade name: Q82214, manufactured by Advantest Corporation) as the light source ( Optical waveguide length 120 mm, incident fiber: measured with GI-50 / 125 multimode fiber (NA = 0.20), outgoing fiber: SI-114 / 125 (NA = 0.22), incident light: effective core diameter 26 μm) Then, when the optical propagation loss after subtracting the insertion loss was measured, the results shown in Table 4 were obtained.

The mirror part 12 of 45 degrees was formed from the upper clad layer 3 side of the obtained optical waveguide 7 using a dicing saw (trade name: DAC552, manufactured by DISCO Corporation) (see FIG. 2 (e) -2; The schematic diagram of a surface perpendicular | vertical to the surface of 2 (e) -1.
Next, in order to observe the cross-sectional shape, the optical waveguide 7 was cut off by 2 mm using the above dicing saw, and the cross-sectional shape was confirmed using a 200 × microscope. As a result, the cross-sectional shape was FIG. The length of the upper side of the upper clad layer 3 side of the core cross section was 49.1 μm, and the length of the lower side of the lower clad layer 1 side was 51.2 μm.

(Formation of optical path conversion mirror protective layer)
As the mirror protective layer 10 for protecting the mirror part 9, the pressure 6 MPa, the temperature 110 ° C., the laminating speed 0. The adhesive layer 6 described in Production Example 1 described in PCT / JP2008 / 05465 is used with a roll laminator. A film adhered to a polyimide film (thickness: 12.5 μm) under the condition of 4 m / min was used as the mirror protective layer 10. Using a vacuum pressure laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.), the mirror protective layer 10 is attached to the mirror forming portion under the conditions of pressure 0.4 MPa, temperature 50 ° C., and pressurization time 30 seconds, 180 The adhesive layer 6 was cured by heat treatment at 0 ° C. for 1 hour, and the mirror protective layer 10 was provided on the mirror portion 9 (see FIG. 2F).

Example 5
The photoelectric composite substrate 8 was produced in the same manner as in Example 4 except that the exposure amount of the core pattern 21 was irradiated at 0.9 J / cm ² .
The optical propagation loss of the thus produced photoelectric composite substrate 8 was measured by the same method as in Example 4, and the results shown in Table 5 were obtained.

実施例１と同様の方法で、コアパタン２１の断面形状を確認した。その結果、断面形状は図５であった。コア断面の上部クラッド層３側の上辺の長さは５０．４μｍで、下部クラッド層１側の下辺の長さは５３．１μｍであった。

In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the upper clad layer 3 side of the core cross section was 50.4 μm, and the length of the lower side of the lower clad layer 1 side was 53.1 μm.

Example 6
The photoelectric composite substrate 8 was produced in the same manner as in Example 4 except that the exposure amount of the core pattern 21 was irradiated at 1.2 J / cm ² .
The optical propagation loss of the thus produced photoelectric composite substrate 8 was measured by the same method as in Example 4, and the results shown in Table 6 were obtained.

実施例１と同様の方法で、コアパタン２１の断面形状を確認した。その結果、断面形状は図６であった。コア断面の上部クラッド層３側の上辺の長さは５１．５μｍで、下部クラッド層１側の下辺の長さは５６．０μｍであった。

In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the upper clad layer 3 side of the core cross section was 51.5 μm, and the length of the lower side of the lower clad layer 1 side was 56.0 μm.

Example 7
Adhesion of the adhesive layer 6 described in PCT / JP2008 / 05465 obtained in Production Example 1 to the polyimide surface of the electrical wiring board 5 after the electrical wiring board 5 after the formation of the insulating protective layer 11 in Example 4 The surface was laminated using a roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd., trade name: HLM-1500) under conditions of a pressure of 0.4 MPa, a temperature of 50 ° C., and a laminating speed of 0.2 m / min.
Thereafter, the adhesive layer 6 was irradiated with 1 J / cm ² of ultraviolet light (wavelength 365 nm) with an ultraviolet exposure machine (trade name: EXM-1172, manufactured by Oak Manufacturing Co., Ltd.), and the carrier film 4 of the adhesive layer 6 was used. A release PET film (Purex A31) was peeled off (see FIG. 3A).
Next, a vacuum pressurizing laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) is attached to the laminated adhesive layer 6 on the lower clad layer 1 side of the optical waveguide 7 formed up to FIG. After vacuuming to 500 Pa or less, thermocompression bonding was performed under the conditions of a pressure of 0.4 MPa, a temperature of 50 ° C., and a pressurization time of 30 seconds. Next, heat treatment was performed at 160 ° C. for 1 hour, the adhesive layer 6 was cured, and a photoelectric composite substrate 8 was obtained (see FIG. 3B).
The optical propagation loss of the thus produced photoelectric composite substrate 8 was measured by the same method as in Example 4, and the results shown in Table 7 were obtained.

次に実施例１と同様の方法で、コアパタン２１の断面形状を確認した。その結果、断面形状は図６であった。コア断面の上部クラッド層３側の上辺の長さは５２μｍで、下部クラッド層１側の下辺の長さは５５．２μｍであった。

Next, the cross-sectional shape of the core pattern 21 was confirmed by the same method as in Example 1. As a result, the cross-sectional shape was FIG. The length of the upper side of the upper clad layer 3 side of the core cross section was 52 μm, and the length of the lower side of the lower clad layer 1 side was 55.2 μm.

Comparative Example 1
The optical waveguide 7 was manufactured in the same process except that the light-emitting agent (D) was not introduced into the resin for forming the lower cladding layer 1 in Example 1.
The optical waveguide thus fabricated was measured for optical propagation loss using the same method as in Example 1, and the results shown in Table 8 were obtained. Compared with the results of Example 1, the average optical propagation loss was large and the variation (Max value−Min value) was also large.

  In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the core section on the upper clad layer 3 side was 548.0 μm, and the length of the lower side of the lower clad layer 1 side was 49.1 μm.

Comparative Example 2
In Example 2, the optical waveguide 7 was produced in the same process except that the light emitting agent (D) was not introduced into the resin for forming the lower cladding layer 1.
The optical waveguide manufactured as described above was measured for light propagation loss using the same method as in Example 1, and the results shown in Table 9 were obtained. Compared with the results of Example 2, the average optical propagation loss was large and the variation (Max value−Min value) was also large.

  In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the core cross section on the upper clad layer 3 side was 50.1 μm, and the length of the lower side of the lower clad layer 1 side was 50.2 μm.

Comparative Example 3
In Example 3, the optical waveguide 7 was produced in the same process except that the light-emitting agent (D) was not introduced into the resin for forming the lower cladding layer 1.
The optical waveguide thus fabricated was measured for optical propagation loss using the same method as in Example 1, and the results shown in Table 10 were obtained. Compared with the results of Example 3, the average optical propagation loss was large and the variation (Max value−Min value) was also large.

  In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the upper clad layer 3 side of the core cross section was 51.0 μm, and the length of the lower side of the lower clad layer 1 side was 52.1 μm.

Comparative Example 4
The photoelectric composite substrate 8 was produced in the same manner as in Example 4 except that the luminescent agent (D) was not introduced into the resin for forming the lower cladding layer 1.
The optical composite substrate 8 thus fabricated was measured for light propagation loss using the same method as in Example 4. The results shown in Table 11 were obtained. Compared with the results of Example 4, the average light propagation loss was large and the variation (Max value−Min value) was also large.

  In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the core section on the upper clad layer 3 side was 47.8 μm, and the length of the lower side of the lower clad layer 1 side was 48.2 μm.

Comparative Example 5
The photoelectric composite substrate 8 was produced in the same manner as in Example 5 except that the luminescent agent (D) was not introduced into the resin for forming the lower cladding layer 1.
The optical composite substrate 8 produced in this way was measured for optical propagation loss using the same method as in Example 4. The results shown in Table 12 were obtained. Compared with the results of Example 5, the average optical propagation loss was large and the variation (Max value−Min value) was also large.

  In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the upper clad layer 3 side of the core cross section was 50.2 μm, and the length of the lower side of the lower clad layer 1 side was 50.6 μm.

Comparative Example 6
The photoelectric composite substrate 8 was produced in the same manner as in Example 6 except that the light emitting agent (D) was not introduced into the resin for forming the lower cladding layer 1.
When the optical propagation loss of the photoelectric composite substrate 8 produced in this manner was measured using the same method as in Example 4, the results shown in Table 13 were obtained. Compared with the results of Example 6, the average optical propagation loss was large and the variation (Max value−Min value) was also large.

  In the same manner as in Example 1, the cross-sectional shape of the core pattern 21 was confirmed. As a result, the cross-sectional shape was FIG. The length of the upper side of the upper clad layer 3 side of the core cross section was 51.1 μm, and the length of the lower side of the lower clad layer 1 side was 53.0 μm.

  The optical waveguide and the optoelectric composite substrate obtained by the manufacturing method of the present invention can be applied to various fields such as various optical devices and optical interconnections.

DESCRIPTION OF SYMBOLS 1 Lower clad layer 2 Core layer 3 Upper clad layer 4 Carrier film 5 Electric wiring board 6 Adhesive layer 7 Optical waveguide 8 Photoelectric composite substrate 9 Mirror part 10 Mirror protective layer 11 Insulating protective layer 21 Core pattern 211 Mainly directly from the exposure light source Core pattern 212 exposed by light Core pattern exposed mainly by light emission of the lower cladding layer

Claims (11)

  In the method of manufacturing an optical waveguide having the step (A) of photocuring the core layer laminated on the lower clad layer by exposure to form a core pattern, the lower clad layer has a feature of emitting light by the exposure, and A method of manufacturing an optical waveguide, wherein the core pattern is exposed by direct light from an exposure light source and light emission from the lower cladding layer.   The manufacturing method of the optical waveguide of Claim 1 which has the process (B) of removing the core layer which is not exposed after the said process (A).   The method for producing an optical waveguide according to claim 1, further comprising a step (C) of laminating an upper clad from the core pattern side.   The optical waveguide manufactured by the method in any one of Claims 1-3.   The optical waveguide according to claim 4, further comprising a core pattern exposed by light emission from the lower clad layer on a side surface portion of the core pattern.   6. The optical waveguide according to claim 4, wherein the optical waveguide is an optical waveguide with a mirror.   4. The optical composite substrate according to claim 1, further comprising a step (D) of laminating the lower clad layer on an electric wiring board before the step (A). Manufacturing method.   8. The method of manufacturing an optoelectric composite substrate according to claim 7, wherein in the step (D), the electric wiring board and the lower clad layer are laminated through at least one adhesive layer.   A photoelectric composite substrate produced by the method according to claim 7 or 8.   6. An optoelectric composite substrate obtained by bonding the optical waveguide according to claim 4 or 5 and an electric wiring board through one or more adhesive layers.   11. The photoelectric composite substrate according to claim 9, wherein the photoelectric composite substrate is a photoelectric composite substrate with a mirror.

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