JP2012128271A - Optical fiber connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber connector which facilitates alignment between an optical fiber and an optical waveguide core and hardly brings about displacement of the optical fiber regardless of a substrate.SOLUTION: In the optical fiber connector, an optical fiber guide member where an optical fiber guiding core pattern having a fiber introduction groove is formed and an optical waveguide where a core pattern for optical signal transmission and an upper clad layer are successively formed on a lower clad layer are juxtaposed on a substrate, and the optical fiber guide member comprises the optical fiber guiding core pattern or a first lower clad layer and the optical fiber guiding core pattern, and the upper clad layer is not formed on the optical fiber guiding core pattern, and the optical fiber guide member and the optical waveguide are juxtaposed so that an optical fiber fixed to the optical fiber introduction groove of the optical fiber guide member is joined to such a position as to be able to transmit an optical signal to the core pattern for optical signal transmission of the optical waveguide.

Description

  The present invention relates to an optical fiber connector, and more particularly to an optical fiber connector in which an optical fiber and an optical waveguide core can be easily aligned, and the optical fiber is not easily displaced without using a hard substrate with good dimensional stability.

In general, an optical cable (also referred to as an optical fiber cable) is widely used for home and industrial information communication because it enables high-speed communication of a large amount of information. For example, automobiles are equipped with various electrical components (for example, a car navigation system), and are also used for optical communication of these electrical components. As an optical cable connector for connecting the ends of optical fibers included in such an optical cable, there is one disclosed in Patent Document 1.
In addition, with the increase in information capacity, development of optical interconnection technology using 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, since light is used for short-distance signal transmission between boards in a router or server device, the optical transmission path has a higher degree of freedom of wiring and higher density than optical fibers. Possible optical waveguides are used.
And as a means to join this optical waveguide and an optical fiber, the optical fiber connector as described in patent document 2 is mentioned, for example.
However, in such an optical fiber connector, since the optical fiber mounting groove needs to be cut by dicing, the working efficiency is poor, and the optical waveguide core is subjected to photolithography and etching in a process different from the groove cutting process. As a result, the optical fiber may be misaligned. Further, in the above-described method, if the substrate is not formed on a hard substrate having good dimensional stability such as a silicon wafer, a larger positional shift of the optical fiber occurs.
In addition, the optical fiber and the optical fiber described in Patent Document 3 are attached to different holders with the waveguide substrate on which the optical waveguide is formed and the optical connector in which the optical fiber is carrier, and the end faces of each holder are fixed together. There is a method for connecting waveguides, but the number of steps until connection is large and complicated.

JP 2010-48925 JP 2001-201646 A JP-A-7-13040

  The present invention has been made in order to solve the above-described problems. The alignment of the optical fiber and the optical waveguide core is easy, and the optical fiber is not easily displaced without using a hard substrate with good dimensional stability. An object is to provide an optical fiber connector.

The present inventor can solve the above-mentioned problems by providing an optical fiber connector in which a fiber guide member and an optical waveguide that do not form an upper cladding layer on an optical fiber guide core pattern are provided side by side. I found out. The present invention has been completed based on such findings.
That is, the present invention
(1) An optical fiber guide member in which an optical fiber guide core pattern having a groove for fixing an optical fiber is formed on a substrate, and an optical signal transmission core pattern is formed on the first lower cladding layer; An optical fiber connector in which an optical waveguide having an upper clad layer formed on the optical signal transmission core pattern is juxtaposed, wherein the optical fiber guide member is an optical fiber guide core pattern or a first lower clad layer And an optical fiber guide core pattern, the upper cladding layer is not formed on the optical fiber guide core pattern, and the optical fiber fixed to the groove of the optical fiber guide member, and the optical fiber The optical fiber guide member and the optical waveguide are juxtaposed so that the optical signal transmission core pattern of the waveguide is joined to a position where the optical signal can be transmitted and received. Optical fiber connector comprising been,
(2) In the above (1), the optical signal transmission core pattern is formed on a first lower cladding layer formed on the substrate, and the optical fiber guide core pattern is formed on the substrate. Optical fiber connector as described,
(3) The above (1) or (2), wherein the substrate is a substrate having an adhesive layer on the substrate, and the first lower cladding layer and the optical fiber guide core pattern are formed on the adhesive layer. An optical fiber connector as described in
(4) The optical fiber connector according to any one of (1) to (3), wherein the adhesive layer is a second lower clad layer (5) The above (1) to (), wherein the substrate is an electric wiring board. 4) the optical fiber connector according to any one of
(6) Any of (1) to (5) above, wherein a height from the substrate surface to the upper surface of the optical fiber guide core pattern in the optical fiber guide member is not less than the radius of the optical fiber and not more than the diameter. An optical fiber connector as described in
(7) The optical fiber connector according to any one of (1) to (6), wherein the optical waveguide of the optical fiber connector is an optical waveguide with an optical path conversion mirror,
Is to provide.

  The optical fiber connector of the present invention allows easy alignment between the optical fiber and the optical waveguide core, and makes it difficult for the optical fiber to be displaced without using a hard substrate with good dimensional stability.

It is a perspective view which shows an example of the optical fiber connector of this invention. FIG. 2 is a cross-sectional view in the parallel direction, viewed from the direction indicated by the arrow in FIG. 1, showing the manufacturing process of the optical fiber connector shown in FIG. 1, and (a) shows the pattern of the center of one optical fiber guide core pattern. FIG. 6B is a cross-sectional view taken along a section cut in the direction parallel to the pattern. FIG. 2 is a vertical cross-sectional view showing a manufacturing process of the optical fiber connector shown in FIG. 1, (c) is a cross-sectional view in a cross section of the optical waveguide cut in the vertical direction, and (d) is a vertical view of the optical fiber guide member. It is sectional drawing in the cross section cut | disconnected in a direction. It is a top view of the junction part of an optical fiber and an optical waveguide of the optical fiber connector shown in FIG.

The optical fiber connector of the present invention will be described with reference to FIGS. The example illustrated in FIGS. 1 to 4 is an example in which the second lower cladding layer 201 is used as the adhesive layer 2. Further, only FIG. 3D-6 shows a state in which the optical fiber 30 is fixed to a part of the optical fiber introduction groove 8.
The optical fiber connector of the present invention has an optical fiber introduction groove 8 for fixing the optical fiber 30 on the second lower cladding layer 201 which is a part of the substrate 1 (see FIG. 3 (d) -6). An optical signal transmission core pattern 4 is formed on the optical fiber guide member 10 on which the fiber guide core pattern 5 is formed, and on the first lower cladding layer 3 formed on the second lower cladding layer 201, and further on the optical signal. An optical fiber connector in which an optical waveguide 20 having an upper clad layer 6 formed on a transmission core pattern 4 is provided side by side, and an optical fiber 30 fixed to an optical fiber introduction groove 8 of an optical fiber guide member 10; The optical signal transmission core pattern 4 of the optical waveguide 20 is joined to a position where an optical signal can be transmitted and received.
However, the upper cladding layer is not formed on the optical fiber guide core pattern 5 in the optical fiber guide member 10.
In the present invention, the optical fiber guide core pattern 5 is for fixing the optical fiber 30 and does not function as a core for transmitting optical signals.
Further, although there is no limitation on the optical fiber to be used, when it is expressed as “optical fiber diameter” below, it represents the cladding outer diameter of the optical fiber or the coating outer diameter of the optical fiber.

Hereinafter, each layer constituting the optical fiber connector of the present invention will be described.
(Lower cladding layer and upper cladding layer)
Hereinafter, the lower clad layers (first lower clad layer, second lower clad layer) 201 and 3 and the upper clad layer 6 used in the present invention will be described. As the lower cladding layers 201 and 3 and the upper cladding layer 6, a cladding layer forming resin or a cladding 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 the optical signal transmission core pattern 4 and is cured by light or heat, and a thermosetting resin composition or photosensitive resin. Can be suitably used. The resin composition used for the resin for forming the clad layer may be the same or different in the components contained in the resin composition in the lower clad layers 201 and 3 and the upper clad layer 6. The refractive indexes may be the same or different. Further, the second lower clad layer 201 is not required to have a refractive index or a photocurable property as long as it has a function as the adhesive layer 2, and an adhesive or a core forming resin film described later may be used.

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, and the clad layer forming resin composition may be applied by a conventional method.
The clad layer-forming resin film used for laminating can be easily produced by, for example, dissolving the clad layer-forming resin composition in a solvent, applying it to a support film, and removing the solvent.

  The thicknesses of the lower cladding layers 201 and 3 and the upper cladding layer 6 are not particularly limited, but 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, it is more preferable that the thicknesses of the lower cladding layers 201 and 3 and the upper cladding layer 6 are further in the range of 10 to 100 μm. The first lower cladding layer 3 has a cured film thickness of [(radius of optical fiber) − (on the first lower cladding layer 3] in order to align the center of the optical fiber with the center pattern of the optical signal transmission core pattern. It is more preferable to use a film having a thickness of the formed optical signal transmission core pattern thickness) / 2].

A specific example shows a preferable thickness of the lower cladding layer 3 when an optical fiber having an optical fiber diameter of 80 μm and an optical fiber core diameter of 50 μm is used. First, when the optical signal propagates from the optical fiber to the optical signal transmission core pattern, the square circumscribing the core diameter of the optical fiber can propagate without optical loss. In this case, the core of the optical waveguide is 50 μm × 50 μm (core height: 50 μm). Applying the above formula, the optimum thickness of the lower cladding layer 3 is 15 μm. In addition, when an optical signal propagates from the optical signal transmission core pattern to the optical fiber using the same optical fiber as described above, a square inscribed in the core diameter of the optical fiber can propagate without optical loss. In this case, the core of the optical waveguide is 40 μm × 40 μm (core height: 40 μm). Applying the above equation, the optimum thickness of the lower cladding layer 3 is 20 μm.
In the optical waveguide 20, the thickness of the upper clad layer 6 for embedding the optical signal transmission core pattern 4 is preferably equal to or greater than the thickness of the optical signal transmission core pattern 4.

(Core layer forming resin and core layer forming resin film)
In the present invention, the method for forming the optical signal transmission core pattern 4 and the optical fiber guide core pattern 5 laminated on the lower clad layers 201 and 3 is not particularly limited. For example, coating of the core layer forming resin or core layer is possible. A core layer may be formed by laminating a forming resin film, and a core pattern may be formed by etching.
In the present invention, the optical waveguide 20 and the optical fiber guide member 10 are each formed with a core layer, and then simultaneously etched to form the optical signal transmission core pattern 4 and the optical fiber guide core pattern 5 simultaneously. An optical fiber connector can be manufactured efficiently.

  The core layer forming resin, in particular, the core layer forming resin used for the optical signal transmission core pattern 4 is designed to have a higher refractive index than the cladding layer 3 and uses a resin composition capable of forming a core pattern with actinic rays. be able to. As described above, the method for forming the core layer before patterning is not limited, and examples thereof include a method for applying the core layer-forming resin composition by a conventional method and a method for using the core layer-forming resin film. .

The thickness of the resin film for forming the core layer is not particularly limited, and the thickness of the core layer after drying is usually adjusted to be 10 to 100 μm. When the thickness of the optical signal transmission core pattern 4 after finishing the film is 10 μm or more, there is an advantage that the alignment tolerance can be increased in coupling with the light emitting / receiving element or the optical fiber after the optical waveguide is formed. In the case of the following, there is an advantage that the coupling efficiency is improved in coupling with the light emitting / receiving element or the optical fiber after the optical waveguide is formed. From the above viewpoint, the thickness of the film is preferably in the range of 30 to 90 μm, and the height from the surface of the substrate 1 to the upper surface of the core pattern for the optical fiber guide is not less than the radius of the optical fiber and not more than the diameter. The film thickness may be adjusted as appropriate in order to obtain the thickness.
In addition, when the thickness of the optical signal transmission core pattern after curing is greater than the core diameter of the optical fiber when transmitting light from the optical fiber to the optical signal transmission core pattern, there is less light loss, and optical signal transmission In the case of transmitting light from the optical core pattern to the optical fiber, it is better to adjust so that the rectangle formed by the thickness and width of the optical signal transmitting core pattern is inside the core diameter of the optical fiber.

The clad layer forming resin film and the core layer forming resin film are preferably formed on a support film.
Examples of the supporting film include, for example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polypropylene, polyamide, polycarbonate, polyphenylene ether, polyether sulfide, polyarylate, liquid crystal polymer, polysulfone, polyethersulfone, Preferred examples include polyether ether ketone, polyether imide, polyamide imide, and polyimide. The thickness of the support film is preferably 5 to 200 μm. When it is 5 μm or more, there is an advantage that the strength as a support film is easily obtained, and when it is 200 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 support film is more preferably in the range of 10 to 100 μm, and particularly preferably 15 to 50 μm.

(substrate)
There is no restriction | limiting in particular as a material of the board | substrate 1, For example, a glass epoxy resin substrate, a ceramic substrate, a glass substrate, a silicon substrate, a plastic substrate, a metal substrate, a substrate with a resin layer, a substrate with a metal layer, a plastic film, with a resin layer Examples thereof include a plastic film, a plastic film with a metal layer, and an electric wiring board.
Base material having flexibility and toughness as the substrate 1, for example, polyester such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polyamide, polycarbonate, polyphenylene ether, polyether sulfide, polyarylate, liquid crystal polymer, By using polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polyamideimide, and polyimide as a substrate, a flexible optical waveguide can be obtained.
Although the thickness of the board | substrate 1 may be suitably changed with the curvature of a board and dimensional stability, Preferably it is 0.1-10.0 mm. Further, the substrate 1 may be peeled off after the optical waveguide is formed. When the optical signal whose optical path has been changed passes through the substrate 1 without removing the substrate 1, it is preferable to use the substrate 1 that is transparent to the wavelength of the optical signal.

(Manufacturing method of optical fiber connector)
The method for manufacturing an optical fiber connector of the present invention will be described in detail in Examples, but basically comprises the following three steps.
(1) After laminating the first lower clad layer forming film on the substrate, the portion for forming the optical fiber introduction groove or the optical fiber guide member is formed by etching the first lower clad layer forming film. A first step of removing the first lower clad layer forming film at a site (a site where an optical fiber introduction groove is formed and a site where an optical fiber guide core pattern is formed).
(2) Laminating the core forming film on the first lower cladding layer left in the first step and on the substrate where the first lower cladding layer forming film has been removed by the first step, and by etching, A second step of collectively forming an optical fiber guide core pattern and an optical signal transmission core pattern;
(3) After laminating an upper cladding layer forming film from the optical fiber guide core pattern and optical signal transmission core pattern forming surface side, etching is performed to etch the optical fiber introduction groove and the upper cladding layer of the optical fiber guide core pattern. A third step of removing the forming film.

In the present invention, the method for fixing the optical fiber 30 to the optical fiber introduction groove 8 of the optical fiber guide member 10 is not particularly limited. For example, the glass block is aligned so that it does not cover the optical waveguide. The fiber may be pressed into the optical fiber introduction groove 8 and the center of the optical signal transmission core pattern 4 and the center of the optical fiber 30 may be aligned and fixed with an adhesive or the like.
At this time, the alignment in the X direction shown in FIG. 4 can be performed by the optical fiber guide core pattern 5, and the alignment in the Z direction can be performed by the substrate 1.

  Further, when the height from the surface of the substrate 1 to the upper surface of the optical fiber guide core pattern 5 in the optical fiber guide member 10 is equal to or larger than the radius of the optical fiber 30, the optical fiber 30 is unlikely to be displaced. When the diameter is equal to or smaller than the diameter, the optical fiber 30 can be easily fixed. Furthermore, it is more preferable that the optical fiber 30 is higher than the radius of the optical fiber 30 by 5 μm or more and lower than the diameter by 3 μm or more because the optical fiber 30 is easy to mount.

In the present invention, the diameter of the optical fiber is preferably 200 μm or less from the viewpoint of easy control of the film thickness of the core layer forming resin film, and it is more preferable to use an optical fiber having a diameter of 125 μm or 80 μm.
The lateral width of the optical fiber introduction groove 8 of the optical fiber guide core pattern 5 may be a width equal to or larger than the diameter of the optical fiber, and is 0.1 to 0.1 mm from the diameter of the optical fiber from the viewpoint of the mountability and tolerance of the optical fiber. It is better if the width is 10 μm.

  In the case of the optical fiber connector of the present invention, the optical fiber guide member 10 is formed by not forming the upper clad layer 6 on the optical fiber guide core pattern 5 (may be removed once formed) in the third step. It is easy to make the height from the surface of the substrate 1 not less than the radius of the optical fiber and not more than the diameter. At this time, the thickness of the upper clad layer 6 formed on the optical signal transmission core pattern 4 is not limited to the thickness, but from the surface of the substrate 1 to the surface of the upper clad layer 6 formed on the optical signal transmission core pattern 4. The height may be equal to or greater than the diameter of the optical fiber 30.

Further, when the optical signal transmission core pattern 4 and the optical fiber guide core pattern 5 are not particularly adhesive to the substrate 1, the substrate 1 with the adhesive layer 2 may be used, and the adhesive layer 2 is the second layer. The lower cladding layer 201 may be used.
Although it does not specifically limit as a kind of contact bonding layer 2, Various adhesives used for a double-sided tape, UV or a thermosetting adhesive, a prepreg, a buildup material, and an electrical wiring board manufacture use are mentioned suitably. When the optical signal whose optical path has been changed passes through the substrate 1, it may be transparent at the optical signal wavelength. In that case, a clad layer-forming resin film or a core layer-forming resin having adhesive strength with the substrate 1 The adhesive layer 2 is preferably formed using a film.

The electric wiring board is not particularly limited, but may be an electric wiring board in which the metal wiring 103 is formed on FR-4, or a flexible wiring board in which the metal wiring 103 is formed on polyimide or polyamide film. There may be. The metal wiring 103 can be formed from the metal layer 102.
The method for smoothing the end face of the optical waveguide connecting the optical fiber 30 and the optical waveguide 20 is not particularly limited. For example, the end face of the optical waveguide is cut using a dicing saw to form the slit groove 9 and smooth the surface. You just have to. The cutting depth of the dicing blade at this time is preferably less than the surface of the substrate 1 because the optical fiber 30 can be satisfactorily mounted.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded.
Example 1
[Preparation of resin film for forming clad layer]
[(A) Base polymer; production of (meth) acrylic polymer (A-1)]
46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate were weighed in a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 47 parts by weight of methyl methacrylate, 33 parts by weight of butyl acrylate, 16 parts by weight of 2-hydroxyethyl methacrylate, 14 parts by weight of methacrylic acid, 2,2′-azobis (2,4-dimethylvaleronitrile ) A mixture of 3 parts by mass, 46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 65 ° C. for 3 hours, and further stirring at 95 ° C. for 1 hour. A (meth) acrylic polymer (A-1) solution (solid content: 45% by mass) was obtained.
[Measurement of weight average molecular weight]
As a result of measuring the weight average molecular weight (in terms of standard polystyrene) of (A-1) using GPC (“SD-8022”, “DP-8020”, and “RI-8020” manufactured by Tosoh Corporation), 3. It was 9 × 10 ⁴ . The column used was “Gelpack GL-A150-S” and “Gelpack GL-A160-S” manufactured by Hitachi Chemical Co., Ltd.
[Measurement of acid value]
As a result of measuring the acid value of A-1, it was 79 mgKOH / g. In addition, the acid value was computed from the amount of 0.1 mol / L potassium hydroxide aqueous solution required for neutralizing A-1 solution. At this time, the point at which the phenolphthalein added as an indicator turned from colorless to pink was defined as the neutralization point.
[Preparation of resin varnish for forming clad layer]
(A) As the base polymer, 84 parts by mass (solid content: 45% by mass) of the A-1 solution (solid content: 45% by mass), (B) Urethane (meth) acrylate having a polyester skeleton as the photocuring component (Shin Nakamura) 33 parts by mass of “U-200AX” manufactured by Chemical Industry Co., Ltd., and 15 parts by mass of urethane (meth) acrylate having a polypropylene glycol skeleton (“UA-4200” manufactured by Shin-Nakamura Chemical Co., Ltd.), (C) heat As a curing component, 20 parts by mass of a polyfunctional block isocyanate solution (solid content: 75% by mass) obtained by protecting an isocyanurate type trimer of hexamethylene diisocyanate with methyl ethyl ketone oxime (“Sumijour BL3175” manufactured by Sumika Bayer Urethane Co., Ltd.) (Solid content 15 parts by mass), (D) As a photopolymerization initiator, 1- [4- (2-hydroxy ester) Xyl) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (“Irgacure 2959” manufactured by Ciba Japan Co., Ltd.), 1 part by mass, bis (2,4,6-trimethylbenzoyl) phenylphosphine 1 part by mass of oxide (“Irgacure 819” manufactured by Ciba Japan Co., Ltd.) and 23 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent for dilution were mixed with stirring. After pressure filtration using a polyflon filter having a pore size of 2 μm (“PF020” manufactured by Advantech Toyo Co., Ltd.), degassing was performed under reduced pressure to obtain a resin varnish for forming a cladding layer.
The resin composition for forming a clad layer obtained above is coated on a non-treated surface of a PET film (“Cosmo Shine A4100” manufactured by Toyobo Co., Ltd., thickness 50 μm) as a support film. -MC, manufactured by Hirano Techy Co., Ltd.), dried at 100 ° C. for 20 minutes, and then subjected to surface release treatment PET film (“Purex A31” manufactured by Teijin DuPont Films, Inc., thickness 25 μm) as a protective film. Was pasted to obtain a resin film for forming a cladding layer. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine. The thicknesses of the first lower cladding layer and the second lower cladding layer (adhesive layer) used in this example are described in the examples. Moreover, the film thickness after hardening of the 1st lower clad layer and the 2nd lower clad layer and the film thickness after coating were the same. The film thickness of the resin film for forming the upper cladding layer used in this example is also described in the examples. The film thickness of the upper clad layer forming resin film described in the examples is the film thickness after coating.

[Preparation 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 resin layer varnish B for forming the core layer obtained above is formed on the non-treated surface of a PET film (trade name: Cosmo Shine A1517, manufactured by Toyobo Co., Ltd., thickness: 16 μm) as a support film. After applying and drying in the same manner, a release PET film (trade name: PUREX A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) is pasted as a protective film so that the release surface is on the resin side. A resin film for layer formation was obtained. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine. The thickness of the resin film for forming a core layer used in this example is described in the examples. The film thickness of the core layer forming resin film described in the examples is the film thickness after coating.

[Production of substrate]
(Electric wiring formation by subtractive method)
Polyimide film 101 with a single-sided copper foil as the metal layer 102 [{polyimide; Upilex VT (manufactured by Ube Nitto Kasei), thickness: 25 μm}, {copper foil; NA-DFF (manufactured by Mitsui Kinzoku Mining Co., Ltd.)), thickness: 9 μm} {See Fig. 2 (a) -1, Fig. 3 (c) -1}] Roll dry laminator with photosensitive dry film resist (trade name: Photec, manufactured by Hitachi Chemical Co., Ltd., thickness: 25 µm) on the copper foil surface. (Hitachi Chemical Technoplant Co., Ltd., HLM-1500) was applied under the conditions of pressure 0.4 MPa, temperature 110 ° C., laminating speed 0.4 m / min, and then an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). ) Was irradiated with 120 mJ / cm ^{2 of} ultraviolet light (wavelength 365 nm) from the photosensitive dry film resist side through a negative photomask with a width of 50 μm. The photosensitive dry film resist in the exposed portion was removed with a dilute solution of 3 wt% sodium carbonate at 35 ° C. Then, using a ferric chloride solution, the exposed copper foil was removed by etching and the exposed dry film resist was removed by etching. The photosensitive dry film resist was removed, and a linear electric wiring 103 of L (line width) / S (gap width) = 60/190 μm was formed to obtain a flexible wiring board. (The optical fiber introduction groove portion is pitch-converted to L (line width) / S (gap width) = 60/65 μm so that the electrical wiring is arranged immediately below the optical fiber guide member.)

(Formation of Ni / Au plating)
Thereafter, the flexible wiring board is degreased, soft etched, acid washed, immersed in an electroless Ni plating sensitizer (trade name: SA-100, manufactured by Hitachi Chemical Co., Ltd.) at 25 ° C. for 5 minutes, and then washed with water. It was immersed in an electroless Ni plating solution at 83 ° C. (manufactured by Okuno Pharmaceutical Co., Ltd., ICP Nicolon GM-SD solution, pH 4.6) for 8 minutes to form a 3 μm Ni film, and then washed with pure water.
Next, immersion gold plating solution (100 mL; HGS-500 and 1.5 g; built bath with potassium gold cyanide / L) (trade name: HGS-500, manufactured by Hitachi Chemical Co., Ltd.) at 85 ° C. for 8 minutes Then, a 0.06 μm displacement gold film was formed on the Ni film. Thereby, the flexible wiring board by which the electrical wiring 103 part without a coverlay film was coat | covered with the plating of Ni and Au was obtained (refer FIG. 2 (a) -2, FIG.3 (c) -2).
The 10 μm-thick clad layer forming resin film obtained above as the adhesive layer 2 (second lower clad layer 201) is cut into a size of 100 × 100 mm, and a release PET film (Purex A31) as a protective film is obtained. After peeling and vacuuming to 500 Pa or less using a vacuum pressurization type laminator (manufactured by Meiki Seisakusho Co., Ltd., MVLP-500) as a flat plate type laminator on the polyimide surface of the flexible wiring board formed above, the pressure is 0.4 MPa. Then, thermocompression bonding was performed under the conditions of a temperature of 100 ° C. and a pressurization time of 30 seconds to form an electric wiring board with the second lower cladding layer 201. By irradiating 4 J / cm ^{2 of} ultraviolet rays (wavelength 365 nm) from the support film side with an ultraviolet exposure machine (manufactured by Oak Manufacturing Co., Ltd., EXM-1172), then peeling the support film and heat-treating at 170 ° C. for 1 hour. Then, the substrate 1 with the second lower cladding layer 201 having a thickness of 10 μm was formed {see FIG. 2A-3 and FIG. 3C-3}.

[Fabrication of optical fiber connector]
The 15 μm-thick lower clad layer-forming resin film obtained above is cut into a size of 100 × 100 μm, the protective film is peeled off, and a vacuum laminator is formed on the second lower clad layer 201 surface side under the same conditions as described above. Laminated. Through a negative photomask having a non-exposed portion of 850 μm × 3.0 mm, UV light (wavelength 365 nm) is irradiated from the support film side with an ultraviolet light exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.) at 250 mJ / cm ^2. did. Thereafter, the support film was peeled off, and the first lower cladding layer 3 was etched using a developer (1% potassium carbonate aqueous solution). Subsequently, the substrate 1 with the first lower cladding layer 3 in which an opening of 850 μm × 3.0 mm was formed in the optical fiber groove forming portion was prepared by washing with water, heating and drying at 170 ° C. for 1 hour, and curing {FIG. 2 (a) -4, FIG. 3 (c) -4, FIG. 3 (d) -4}. As a result, the first lower cladding layer 3 is formed in the portion where the optical waveguide 20 is formed, and the first lower cladding layer 3 is not present in the portion where the optical fiber guide member 10 is formed.
Next, a roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd., HLM-1500) is used on the surface of the first lower clad layer 3 (where the portion without the first lower clad layer 3 is the surface of the substrate 1) with a pressure of 0. The core layer forming resin film having a thickness of 50 μm from which the protective film was peeled off was laminated under the conditions of 4 MPa, temperature of 50 ° C., and lamination speed of 0.2 m / min, and then the above-described vacuum pressure laminator (manufactured by Meiki Seisakusho Co., Ltd.) , MVLP-500) was evacuated to 500 Pa or less, and then thermocompression bonded under conditions of a pressure of 0.4 MPa, a temperature of 70 ° C., and a pressurization time of 30 seconds. Thereafter, the core pattern width for optical signal transmission is 50 μm (pattern pitch on the optical fiber introduction groove 8 side; 125 μm, 4 lines), and the non-exposed portion width for forming the optical fiber introduction groove 8 is 85 μm (optical fiber groove pitch: 250 μm, 4 The optical signal transmission core pattern 4 is formed on the first lower cladding layer 3 and the optical fiber introduction groove 8 formed by the optical fiber guide core pattern 5 is formed on the substrate 1 (second lower portion) through a negative photomask of the present book. The film was aligned so as to be formed on the cladding layer 201), irradiated with 700 mJ / cm ^{2 of} ultraviolet rays (wavelength 365 nm) with the above-described ultraviolet exposure machine, and then heated after exposure at 80 ° C. for 5 minutes. Thereafter, the PET film as the support film was peeled off, and the core pattern was etched using a developer (propylene glycol monomethyl ether acetate / N, N-dimethylacetamide = 8/2, mass ratio). Subsequently, the substrate is cleaned using a cleaning solution (isopropanol), and is heated and dried at 100 ° C. for 10 minutes to form the optical signal transmission core pattern 4 and the optical fiber guide core pattern 5. At the same time, an optical fiber introduction groove 8 having a width of 85 μm. Formed. The size of each pattern in the optical fiber guide core pattern 5 is such that the optical fiber can transmit an optical signal to the optical signal transmission core pattern 4 when the optical fiber is fixed to the optical fiber introduction groove 8. Designed to be joined {see FIG. 2 (a) -5, FIG. 2 (b) -5, FIG. 3 (c) -5, FIG. 3 (d) -5, FIG. 4}.

Next, after the upper cladding layer resin film having a thickness of 60 μm from which the protective film has been peeled is evacuated to 500 Pa or less using the above-described vacuum pressure laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) from the core pattern forming surface side. The film was laminated by thermocompression bonding under the conditions of a pressure of 0.4 MPa, a temperature of 110 ° C., and a pressing time of 30 seconds. Further, using a negative photomask having only the upper part of the optical signal transmission core pattern 4 opened, ultraviolet light (wavelength 365 nm) was irradiated with 150 J / cm ² , the support film was peeled off, and a developer (1% potassium carbonate aqueous solution) Was used to etch the resin film for forming the upper cladding layer of the optical fiber introduction groove 8 and the optical fiber guide core pattern 5. Subsequently, it was washed with water, heated and dried at 170 ° C. for 1 hour, and cured to produce an optical fiber connector for a 125 μm pitch, a fiber diameter of 80 μm, and four channels.
In the obtained optical fiber connector, the lateral width of the optical fiber introduction groove 8 of the optical fiber guide core pattern 5 is 85 μm, the height of the optical fiber guide core pattern 5 is 64 μm, and the thickness of the optical signal transmission core pattern 4 is 51 μm. {See Fig. 2 (a) -6, Fig. 2 (b) -6, Fig. 3 (c) -6, Fig. 3 (d) -6}.

(Slit groove formation)
A slit groove 9 having a width of 40 μm was formed by using a dicing saw (DAC552, manufactured by Disco Corporation) in order to smooth the optical fiber connection end face of the obtained optical waveguide 20 {FIG. 2 (a) -6, FIG. 2 (b) -6}. In addition, the substrate was cut in parallel to the fiber guide core (3 mm from the end face of the optical waveguide), and the outer shape was processed so that the fiber groove appeared on the end face of the substrate {see FIG. 1}.
(Formation of optical path conversion mirror)
A 45 ° optical path conversion mirror 11 was formed from the upper clad layer 6 side of the obtained optical waveguide 20 using a dicing saw (DAC552, manufactured by DISCO Corporation) {FIGS. 2 (a) -7, 2 (b) ) -7}. Next, a metal mask having an opening in the mirror formation portion was placed on an optical fiber connector with a mirror, and Au was vapor-deposited by 0.5 μm as a vapor-deposited metal layer 12 using a vapor deposition apparatus (RE-0025, manufactured by First Giken) {FIG. 2 (a) -8, FIG. 2 (b) -8, FIG. 3 (f)}.
In the optical fiber introduction groove 8 of the optical fiber connector obtained as described above, a 125 μm pitch, 4-channel optical fiber 30 (core diameter: 50 μm, clad diameter: 80 μm) is suppressed with a glass block (the glass block is When the optical fiber is introduced into the optical fiber introduction groove 8 (positioned so as not to cover the optical waveguide 20), it is bonded to the optical transmission surface of the optical signal transmission core pattern 5 of the optical waveguide 20 and an optical signal is transmitted from the optical fiber 30. Was possible.

As described in detail above, the optical fiber connector of the present invention is easy to align the optical fiber and the optical waveguide core, and the optical fiber is not easily displaced without using a hard substrate with good dimensional stability, And pattern formation of a core layer and a clad layer is easy, and it is easy to control total thickness.
Therefore, it is useful as a photoelectric conversion substrate for optical fibers.

1. Substrate 101. Polyimide film 102. Metal layer 103. Metal wiring, electrical wiring Adhesive layer 201. Lower cladding layer (second lower cladding layer)
3. Lower cladding layer (first lower cladding layer)
4). 4. Optical signal transmission core pattern 5. Core pattern for optical fiber guide 6. Upper clad layer Gaps 8. 8. Optical fiber introduction groove Slit groove 10. 10. Optical fiber guide member Optical path conversion mirror 12. Deposition metal layer 20. Optical waveguide 30. Optical fiber

Claims (7)

An optical fiber guide member in which an optical fiber guide core pattern having a groove for fixing an optical fiber is formed on a substrate, and an optical signal transmission core pattern is formed on a first lower cladding layer, and the optical signal An optical fiber connector in which an optical waveguide having an upper clad layer formed on a transmission core pattern is provided in parallel,
The optical fiber guide member comprises an optical fiber guide core pattern or a first lower clad layer and an optical fiber guide core pattern, and no upper clad layer is formed on the optical fiber guide core pattern, And the optical fiber guide member and the optical fiber fixed to the groove of the optical fiber guide member and the optical signal transmission core pattern of the optical waveguide are joined to a position where an optical signal can be transmitted and received. An optical fiber connector in which optical waveguides are juxtaposed.   2. The optical fiber according to claim 1, wherein the optical signal transmission core pattern is formed on a first lower clad layer formed on the substrate, and the optical fiber guide core pattern is formed on the substrate. connector.   The optical fiber connector according to claim 1, wherein the substrate is a substrate having an adhesive layer on the substrate, and the first lower cladding layer and the optical fiber guide core pattern are formed on the adhesive layer. .   The optical fiber connector according to claim 1, wherein the adhesive layer is a second lower cladding layer.   The optical fiber connector according to claim 1, wherein the substrate is an electric wiring board.   The light according to any one of claims 1 to 5, wherein a height from a substrate surface to an upper surface of the optical fiber guide core pattern in the optical fiber guide member is not less than a radius of the optical fiber and not more than a diameter. Fiber connector.   The optical fiber connector according to claim 1, wherein the optical waveguide of the optical fiber connector is an optical waveguide with an optical path conversion mirror.

Images