JP5707969B2 - Optical waveguide with mirror and manufacturing method thereof, flexible waveguide with mirror and manufacturing method thereof, optical fiber connector with mirror and manufacturing method thereof - Google Patents

Description

  The present invention can reduce the film thickness of the optical waveguide and can protect the metal layer of the mirror part in the process, and the manufacturing method of the optical waveguide with the mirror, the optical waveguide with the mirror, and the manufacturing method of the flexible optical waveguide with the mirror obtained thereby. The present invention relates to a flexible optical waveguide with a mirror, a manufacturing method of an optical fiber connector with a mirror, and an optical fiber connector with a mirror obtained thereby.

  With the increase in information capacity, development of 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, and for personal computers and mobile phones in consumer devices Yes. 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. In addition, for personal computers and mobile phones, which are consumer devices, an optoelectric composite substrate in which an optical transmission path is combined with a flexible electrical wiring board between a keyboard and a display has been developed. As an 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 in particular, an optical waveguide that uses a polymer material with excellent workability and economy. Is promising.

  As a manufacturing method of this optical waveguide, for example, as described in Patent Document 1, first, a lower cladding layer is cured and formed, then a core pattern is formed on the lower cladding layer, and the upper cladding layer is laminated. Forming an optical waveguide. Thereafter, a method of forming a notch for optical path conversion, forming a metal layer in the notch, and filling the notch with a clad layer from the metal layer forming surface side has been used. However, this method is not suitable for space saving because the optical waveguide becomes thicker by the amount of the cladding layer in which the notch is embedded. Further, when the optical waveguide is used in a hinge portion of a personal computer or a mobile phone, there is a problem that the flexibility is lowered when the optical waveguide is thickened. On the other hand, if the notch is not embedded, for example, the metal layer may be peeled off when the outer shape is processed by a dicing saw after the metal layer is formed.

Also known is an optical fiber connector having an optical waveguide and an optical fiber mounting groove capable of joining optical fibers (Patent Document 2).
However, after the metal layer is formed in the notch, if the notch is filled with a thermosetting liquid adhesive, the liquid adhesive flows into the optical fiber mounting groove and is introduced when the optical fiber is actually introduced. There was something I couldn't do.

JP 2009-169437 A JP 2001-201646 A

  The present invention has been made to solve the above-described problems, and a method for manufacturing an optical waveguide with a mirror capable of reducing the thickness and protecting the mirror portion made of a metal layer, and reducing the thickness and protecting the mirror portion. In addition to the manufacturing method of a flexible optical waveguide capable of maintaining high flexibility and high flexibility, the filling material of the cutout portion does not flow into and remain in places other than the cutout portion of the optical fiber mounting groove, etc. It is an object of the present invention to provide an optical fiber connector manufacturing method capable of satisfactorily introducing an optical fiber therein, and an optical waveguide, a flexible optical waveguide, and an optical fiber connector manufactured by these methods.

The present invention provides the following inventions (1) to (12).
(1) An optical waveguide having a lower clad layer, an optical signal transmission core pattern, and an upper clad layer, an optical path changing notch provided in the optical waveguide, and an optical path changing present in the notch a mirror and a manufacturing method of the mirrored optical waveguide having a step a ₁ for forming the cutout portion in the optical waveguide, step B ₁ of forming the mirror made of a metal layer on the notch, the photosensitive Step C ₁ for filling the notch with a conductive resin layer, and Step D ₁ for patterning the photosensitive resin layer and removing at least a part of the photosensitive resin layer other than the notch. The manufacturing method of the optical waveguide with a mirror which has.
(2) The method for producing an optical waveguide with a mirror according to (1), wherein the photosensitive resin layer is made of the same material as at least one of the lower cladding layer, the core pattern, and the upper cladding layer.
(3) An optical waveguide with a mirror manufactured by the method according to (1) or (2).
(4) a substrate, and an optical waveguide with a mirror and an optical fiber guide member arranged side by side on the substrate, wherein the optical waveguide with a mirror includes a lower cladding layer, an optical signal transmission core pattern, and an upper portion An optical waveguide having a cladding layer, an optical path changing notch provided in the optical waveguide, and an optical path changing mirror present in the notch, the optical fiber guide member, An optical fiber mounting groove for fixing the optical fiber, the optical fiber fixed in the optical fiber mounting groove of the optical fiber guide member, and the optical signal transmission core pattern of the optical waveguide, The optical fiber guide member and the optical waveguide are arranged in parallel so as to be in a position where the optical fiber can be transmitted and received. Step A ₂ to form a part, step B ₂ to form the mirror made of a metal layer on the notch, Step C ₂ filling the notch by the photosensitive resin layers, and the photosensitive resin layer the patterned method of mirrored optical fiber connector comprising the step D ₂ of removing at least the photosensitive resin layer of the optical fiber mounting groove.
(5) The manufacturing method of the optical fiber connector with a mirror as described in (4) whose said board | substrate is an electrical wiring board.
(6) The manufacturing of the optical fiber connector with a mirror according to (4) or (5), wherein the photosensitive resin layer is made of the same material as at least one of the lower clad layer, the pattern, and the upper clad layer. Method.
(7) An optical fiber connector with a mirror manufactured by the method according to any one of (4) to (6).
(8) A flexible optical waveguide having a lower clad layer, an optical signal transmission core pattern, an upper clad layer, an optical path changing notch provided in the flexible optical waveguide, and an optical path changing present in the notch A method of manufacturing a flexible optical waveguide with a mirror having a mirror for use in the step A ₃ of forming the notch in the flexible optical waveguide, and forming an optical path changing mirror made of a metal layer in the notch Step B ₃ , filling the cut-out portion with a photosensitive resin layer C ₃ , patterning the photosensitive resin layer, and at least one of the photosensitive resin layers in the bent portion of the flexible optical waveguide method for producing a flexible optical waveguide with a mirror having a step D ₃ of removing the part.
(9) An adhesive layer forming step of forming an adhesive layer on the substrate to form a substrate with an adhesive layer, and an optical waveguide forming step of forming the flexible optical waveguide on the adhesive layer of the substrate with the adhesive layer after implementation, the step a ₃ to D ₃ production method of mirrored flexible optical waveguide according to embodiment (8).
(10) The method for producing a flexible optical waveguide with a mirror according to (9), wherein the substrate is an electric wiring board.
(11) The flexible light with a mirror according to any one of (8) to (10), wherein the photosensitive resin layer is made of the same material as at least one of the lower cladding layer, the core pattern, and the upper cladding layer. A method for manufacturing a waveguide.
(12) A flexible optical waveguide with a mirror manufactured by the method according to any one of (8) to (11).

  According to the present invention, the optical waveguide with a mirror having a small thickness and capable of protecting the mirror portion, the flexible optical waveguide capable of maintaining high flexibility in addition to the reduction of the thickness and the protection of the mirror portion, and the filling material for the notch portion It is possible to manufacture an optical fiber connector in which the optical fiber can be satisfactorily introduced into the optical fiber mounting groove without flowing into and remaining in portions other than the notch such as the optical fiber mounting groove.

It is sectional drawing which shows an example of the manufacturing method of the optical waveguide with a mirror of this invention. FIG. 2 is a plan view of FIG. It is a typical perspective view of the optical waveguide manufactured by an example of the manufacturing method of the optical fiber connector with a mirror of the present invention. It is the perspective view which abbreviate | omitted the photosensitive resin 26 in FIG. It is sectional drawing which shows an example of the manufacturing method of the optical fiber connector with a mirror of this invention. It is sectional drawing which shows an example of the manufacturing method of the optical fiber connector with a mirror of this invention. It is sectional drawing which shows an example of the manufacturing method of the optical fiber connector with a mirror of this invention. It is sectional drawing which shows an example of the manufacturing method of the optical fiber connector with a mirror of this invention. It is sectional drawing which shows an example of the manufacturing method of the optical fiber connector with a mirror of this invention. It is sectional drawing which shows an example of the manufacturing method of the flexible optical waveguide with a mirror of this invention.

[First embodiment (manufacturing method of optical waveguide with mirror)]
Below, an example of the manufacturing method of the optical waveguide with a mirror concerning the present invention is explained with reference to drawings. FIG. 1 is a cross-sectional view showing an example of a manufacturing method of an optical waveguide with a mirror of the present invention, and FIG. 2 is a plan view of FIG. 1 (d).
For convenience of explanation, the schematic configuration of the optical waveguide with a mirror manufactured by the manufacturing method of the optical waveguide with a mirror according to the present embodiment will be described first, and then the manufacturing method of the optical waveguide with a mirror according to the present embodiment. Will be described.

<Schematic configuration of optical waveguide with mirror>
FIG. 1 (g) shows a cross-sectional view of a mirrored optical waveguide manufactured by a method of manufacturing a mirrored optical waveguide described later. Hereinafter, the configuration of the optical waveguide with a mirror will be described mainly with reference to FIG.
As shown in FIG. 1 (g), an optical waveguide 9 with a mirror according to this embodiment includes an optical waveguide 8 (optical waveguide 8) having a lower cladding layer 2, an optical signal transmission core pattern 3, and an upper cladding layer 4. 1 (d)), an optical path changing notch 5 provided in the optical waveguide 8, and an optical path changing mirror 6 present in the notch 5. The notch 5 is filled with a photosensitive resin 7.
The optical waveguide 9 with a mirror according to the present embodiment is characterized in that the photosensitive resin 7 is formed only in the notch portion 5 and its vicinity, and other than the vicinity of the notch portion 5 in the upper surface of the upper clad layer 4. The photosensitive resin 7 is not formed in the place. Thereby, while being able to protect a mirror with the photosensitive resin 7, thickness of parts other than the notch part vicinity can be made small among the optical waveguides 9 with a mirror. The mirrored optical waveguide 9 is formed on the substrate 1.

  By installing a light emitting / receiving element on the lower surface of the substrate 1 of the optical waveguide 9 with a mirror configured as described above, an optical signal can be transmitted / received between the light receiving / emitting elements. For example, a light emitting element is installed at a lower position on the right side of the left notch 5 on the lower surface of the substrate 1, and a light emitting element is positioned on the lower side of the left side of the right notch 5 on the lower surface of the substrate 1. Is installed. An optical signal emitted upward from the light emitting element passes through the substrate 1, the lower cladding layer 2, and the core pattern 3 and is optically converted in the core pattern extending direction (right direction in the drawing) by the left mirror 6, and then the right side. The light is converted downward by the mirror 6, passes through the lower cladding layer 2 and the substrate 1, and is received by the light receiving element. An optical fiber may be installed in place of these light emitting / receiving elements. That is, an optical fiber may be installed at the installation position of the light emitting element instead of the light emitting element, and an optical signal may be transmitted from the optical fiber. In addition, an optical fiber may be installed at the installation position of the light receiving element instead of the light receiving element so that the optical fiber receives an optical signal.

<Method of manufacturing optical waveguide with mirror>
The manufacturing method of the optical waveguide 9 with a mirror described above includes the step A of forming the notch 5 in the optical waveguide 8, the step B of forming the mirror 6 made of a metal layer in the notch 5, and the photosensitive resin layer. A process C for filling the notch part 5 and a process D for patterning the photosensitive resin layer and removing the photosensitive resin layer other than the notch part are included.
Further, in the present embodiment, an optical waveguide forming step for forming the optical waveguide 8 without the notched portion 5 on the substrate 1 is provided before the notched portion forming step A.
Hereinafter, these steps will be described in detail.

(Optical waveguide forming step (FIGS. 1 (a) to (d))
In the present embodiment, the optical waveguide 8 is built up on the substrate 1.
First, the lower cladding layer 2 is formed on the entire surface of the substrate 1 (FIGS. 1A and 1B). Next, a core layer is laminated on the lower cladding layer 2 and patterned to form the core pattern 3 (FIG. 1 (c)). In the present embodiment, two core patterns 3 having the same rectangular parallelepiped shape are formed so as to be parallel to each other (see FIG. 2). Thereafter, an upper clad layer 4 is formed on the lower clad layer 2 so as to cover these core patterns 3. In this way, the optical waveguide 8 is formed.
Hereinafter, each member which comprises this optical waveguide 8 is demonstrated in detail.

Substrate The material of substrate 1 is not particularly limited. For example, glass epoxy resin substrate, ceramic substrate, glass substrate, silicon substrate, plastic substrate, metal substrate, substrate with resin layer, substrate with metal layer, plastic film, resin layer For example, a plastic film with a metal 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, the optical waveguide with a mirror may be a flexible optical waveguide with a mirror.
The thickness of the substrate may be appropriately changed depending on the warp and dimensional stability of the plate, but is preferably 0.1 to 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.

Lower clad layer and upper clad layer As the lower clad layer 2 and the upper clad layer 4, a clad layer forming resin or a clad layer forming resin film can be used.
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 carrier film, and removing the solvent.

  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 pattern 3 and is cured by light or heat, and the thermosetting resin composition or the photosensitive resin composition. Can be preferably used. In the lower clad layer 2 and the upper clad layer 4, the resin composition used for the clad layer forming resin may have the same or different components contained in the resin composition, and the refractive index of the resin composition May be the same or different.

The thickness of the lower clad layer 2 and the upper clad layer 4 is 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, the thickness of the lower cladding layer 2 and the upper cladding layer 4 is more preferably in the range of 10 to 100 μm.
The thickness of the upper cladding layer 4 is preferably equal to or greater than the thickness of the core pattern 3.

Core Pattern In the present invention, the method for forming the core pattern 3 is not particularly limited. For example, the core layer is formed by coating the core layer forming resin or laminating the core layer forming resin film, and the core pattern is formed by etching. Just do it.
The resin for forming the core layer may be a resin composition that is designed to have a higher refractive index than the cladding layers 2 and 4 and can form a core pattern with actinic rays. The method of forming the core layer before patterning is not limited, and examples thereof include a method of applying the core layer forming resin composition by a conventional method.

  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 core pattern 3 after finishing 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 forming the optical waveguide, and the thickness is 100 μm or less. In addition, 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.

  The clad layer forming resin film and the core layer forming resin film are preferably formed on a carrier film. Examples of carrier films include flexible and tough carrier films such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and the like, polyethylene, polypropylene, polyamide, polycarbonate, polyphenylene ether, polyether sulfide, poly Preferable examples include arylate, liquid crystal polymer, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polyamideimide, and polyimide. The thickness of the carrier film is preferably 5 to 200 μm. When it is 5 μm or more, there is an advantage that the strength as a carrier 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 carrier film is more preferably in the range of 10 to 100 μm, and particularly preferably 15 to 50 μm. A carrier film may be used as the substrate 1.

(Process A ₁ (FIG. 1 (e))
In this step, the notch 5 is formed in the optical waveguide 8 obtained in the optical waveguide formation step. The method for forming the notch 5 is not particularly limited, but can be formed by cutting with a dicing saw or laser ablation. When a dicing saw is used, the optical path can be changed in the direction of the substrate 1 by cutting the notch 5 at 45 °.

In the present embodiment, two notches 5 extending in the direction orthogonal to the longitudinal direction of the core pattern 3 are formed. The notch 5 has a V-shaped cross section perpendicular to the extending direction, and extends over two opposing long side surfaces of the optical waveguide 8. The normals of the two side surfaces of each notch 5 are inclined in the vertical direction with respect to the extending direction of the core pattern 3. The inclination angle formed between the normal line of the side surface of the notch 5 and the extending direction of the core pattern 3 can be appropriately set according to the use, but is preferably 30 to 60 °, more preferably 40 to 50. °, more preferably 44 to 46 °. However, each core pattern 3 has a total of four side surfaces of the two cutout portions 5, but it is sufficient that at least one of these four side surfaces is inclined and the other side surface is not inclined. (That is, the normal of the side surface of the notch 5 may be parallel to the extending direction of the core pattern 3).
The lower end of the notch 5 only needs to reach at least a part of the core pattern 3, but it is preferable that the lower end of the notch 5 reaches below the lower surface of the core pattern 3 from the viewpoint of reducing optical loss.

(Process B ₁ (FIG. 1 (f))
In this step, a mirror 6 made of a metal layer is formed in the notch 5.
A method for forming the mirror 6 is not particularly limited, and methods such as vapor deposition, sputtering, and plating are preferable. The type of metal to be formed is not particularly limited, and examples thereof include various metals such as Au, Ag, Cu, Ti, Ni, Pd, and Al. From the viewpoint of reflectivity, it is more preferable to use Au or Al because a high reflectivity can be obtained. Moreover, the thickness of the metal layer 12 to be formed may be a thickness within a range that does not transmit an optical signal. In the case of Au or Al, it may be appropriately adjusted within a range of 0.1 μm to 2 μm.
In the present embodiment, the mirror 6 is formed on all the side surfaces of all the cutout portions 5, but is not limited to this. The mirror 6 may be formed only on the central side surface of the waveguide 8. Even in this case, the optical signal that has entered the optical waveguide 8 from the substrate 1 side is reflected by one mirror 6, converted into an optical path in the extending direction of the core pattern 3, and travels to the other mirror 6. Next, the optical path is again changed by the other mirror 6 and emitted from the substrate 1 side to the outside of the optical waveguide 8.

(Process C ₁ )
In this step, the notch 5 is filled with the photosensitive resin layer 7.
The method of filling the notch 5 with the photosensitive resin layer 7 is not particularly limited, but the photosensitive resin may be filled by spin coating or the like, using a dry film-shaped resin, a roll laminator, a vacuum What is necessary is just to fill with a laminator, a vacuum roll laminator, a normal pressure press, a vacuum press, etc. If a vacuum laminator, a vacuum roll laminator, or a vacuum press is used, generation of bubbles can be suppressed in the cutout portion 5, and if a vacuum laminator or a vacuum press is used, the surface of the photosensitive resin layer 7 can be smoothed. Still good.

(Process D ₁ (FIG. 1 (g))
In this step, the photosensitive resin layer 7 is patterned, and the photosensitive resin layer other than the notch 5 is removed. The removal method is not particularly limited. If the photosensitive resin layer is a positive type, the photosensitive resin layer 7 may be exposed and etched to remove the photosensitive portion, and may be a negative type. For example, the photosensitive resin 7 may be exposed and the non-photosensitive portion may be removed by etching.

Photosensitive resin layer In the present invention, the material of the photosensitive resin layer 7 for filling the notch 5 is not particularly limited as long as it can be patterned through an exposure / etching process. Further, it is preferable that the material has the same elastic modulus as that of the core pattern 3 or the upper clad layer 4. When the above-described resin for forming the clad layer or the resin for forming the core layer is used, the stress applied to the mirror 6 made of the metal layer is reduced. It is even better because it can be reduced. Further, the thickness of the photosensitive resin 7 is not particularly limited, and may be in a range in which the cutout portion 5 can be embedded. However, the thickness is more than the depth of the cutout portion 5.
Further, the range in which the photosensitive resin layer 7 is left is not particularly limited. However, if the mirror 6 formed in the notch 5 is covered (wider than the formation range of the mirror 6), peeling of the mirror 6 is suppressed. Can do. Furthermore, if the range in which the photosensitive resin 7 is left as much as possible is reduced, for example, the total product thickness when an electric wiring board or a second optical waveguide is laminated on the upper clad layer 4 can be reduced. In the case of a flexible optical waveguide or a flexible optoelectric composite substrate, it may be left so as not to be applied to the bent portion 13.

  The mirrored optical waveguide 9 can be manufactured as described above. The obtained optical waveguide 9 with a mirror can protect the mirror 6 because the notch 5 is filled with the photosensitive resin 7. Further, in the obtained optical waveguide 9 with a mirror, the thickness of portions other than the portion where the photosensitive resin 7 is formed becomes small. When the optical waveguide 9 with a mirror is a flexible optical waveguide with a mirror, the optical waveguide 9 with a mirror can be easily bent at the central portion where the photosensitive resin 7 is not formed (FIG. 1 (g) )).

[Second Embodiment (Manufacturing Method of Optical Fiber Connector with Mirror)]
Below, an example of the manufacturing method of the optical fiber connector with a mirror which concerns on this invention with reference to drawings is demonstrated. FIG. 3 is a schematic perspective view of the optical fiber connector with a mirror manufactured by an example of the manufacturing method of the optical fiber connector with a mirror of the present invention. FIG. 4 is a schematic view of the photosensitive resin 26 and the mirror 25 in FIG. It is the perspective view which abbreviate | omitted. 5 to 9 are cross-sectional views showing an example of the manufacturing method of the optical fiber connector with a mirror according to the present invention. 5 (i) corresponds to a cross section taken along line VV in FIG. 3, and FIG. 6 (i) corresponds to a cross section taken along line VI-VI in FIG. f) corresponds to a sectional view taken along line VII-VII in FIG. 3, and FIG. 8 (f) corresponds to a sectional view taken along line VIII-VIII in FIG. FIG. 9 is a plan view of the states of FIGS. 5 (e), 6 (e), 7 (e) and 8 (e). In FIG. 8 (f), the optical fiber 50 is depicted.
For convenience of explanation, a schematic configuration of an optical fiber connector with a mirror manufactured by the method for manufacturing an optical fiber connector with a mirror according to the present embodiment will be described first, and then manufacturing of the optical fiber connector with a mirror according to the present embodiment will be described. A method will be described.
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.

<Schematic configuration of optical fiber connector with mirror>
The optical fiber connector 40 with a mirror according to the present embodiment includes a substrate 11, an optical waveguide with a mirror and an optical fiber guide member 30 that are arranged in parallel on the substrate 11. The optical waveguide with a mirror includes an optical waveguide 20 having a lower cladding layer 21, an optical signal transmission core pattern 22, and an upper cladding layer 23, an optical path changing notch 24 provided in the optical waveguide 20, and a notch. And an optical path changing mirror 25 existing in the unit 24. The optical fiber guide member 30 has an optical fiber mounting groove 38 for fixing the optical fiber 50. The optical fiber 50 fixed to the optical fiber mounting groove 38 of the optical fiber guide member 30 and the optical signal transmission core pattern 22 of the optical waveguide 20 are positioned so that the optical signal can be transmitted and received. The guide member 30 and the optical waveguide 20 are arranged in parallel. The notch 24 is filled with a photosensitive resin 26. Metal wiring 13 is formed on the lower surface of the substrate 11.

  The optical fiber connector 40 with a mirror according to the present embodiment is characterized in that the photosensitive resin 26 is formed only in the notch 24 and its vicinity, and other than the vicinity of the notch 24 in the upper surface of the upper clad layer 23. This is because the photosensitive resin 26 is not formed. Thereby, while being able to protect the mirror 25 with the photosensitive resin 26, the thickness of parts other than the notch 24 and its vicinity among optical fiber connectors with a mirror can be made small.

In order to attach the optical fiber 50 to this optical fiber connector with a mirror, the optical fiber 50 may be inserted into the optical fiber mounting groove 38 (see FIGS. 3 and 8 (c)).
By attaching the optical fiber 50 to the mirror-equipped optical fiber connector 40 configured in this way and installing the light emitting / receiving element on the lower surface of the substrate 1, the space between the optical fiber 50 and the light emitting / receiving element is set. Can transmit and receive optical signals. That is, the optical signal from the optical fiber 50 is optically converted downward by the mirror 25 through the core pattern 22 and reaches the lower surface of the substrate 1, and is converted into an electric signal by the light emitting and receiving elements installed on the lower surface of the substrate 1. This electric signal is transmitted to the metal wiring 13. The optical signal transmitted upward from the light emitting / receiving element is optically converted in the extending direction of the core pattern 22 by the mirror 25 and transmitted to the optical fiber 50.

<Manufacturing method of optical fiber connector with mirror>
The manufacturing method of the optical fiber connector with a mirror described above includes the step A of forming the notch 24 in the optical waveguide 20, the step B of forming the mirror 25 made of a metal layer in the notch 24, and the photosensitive resin layer 26. A process C for filling the notch 24 and a process D for patterning the photosensitive resin layer 26 and removing the photosensitive resin layer 26 other than the optical fiber mounting groove 24 are included.
In this embodiment, an optical fiber connector (notch) that forms the optical waveguide 20 and the optical fiber guide member 30 on the substrate 11 without the notch 5 before the notch formation step A is formed. (Notch portion not installed) forming step.
Hereinafter, these steps will be described in detail.

(Optical fiber connector formation process)
In this optical fiber connector forming step, the following steps (1) to (3) are sequentially performed.
(1) Metal Wiring Formation Step In this step, the metal wiring 13 is formed on the lower surface of the substrate 11. The metal wiring 13 can be formed by forming the metal layer 12 on the lower surface of the substrate 1 by a conventional method and etching the metal layer 12 (FIGS. 5A to 5B, FIG. 6). (A)-(b), FIG. 7 (a)-(b), FIG. 8 (a)-(b)).
The metal wiring board in which the metal wiring 13 is formed on the substrate 11 in this way is not particularly limited, but may be an electric wiring board in which the metal wiring 13 is formed on FR-4, and the metal wiring 13 is polyimide. Or a flexible wiring board formed on a polyamide film.

(2) Formation Step of Adhesive Layer 14 In this step, the adhesive layer 14 is formed on the upper surface of the substrate 1 (FIGS. 5 (c), 6 (c), 7 (c) and 8 (c). c)). The adhesive layer 14 is for ensuring the adhesiveness between the optical waveguide 20 and the optical fiber guide member 30 and the substrate 11.
Although it does not specifically limit as a kind of adhesive layer 14, The various adhesives used for a double-sided tape, UV or a thermosetting adhesive agent, 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 11, it may be transparent at the optical signal wavelength. In that case, a resin film for forming a clad layer or a resin film for forming a core layer that has an adhesive force with the substrate 11. The adhesive layer 14 is preferably used.

(3) Formation Step of Optical Waveguide and Optical Fiber Guide Member In the present embodiment, the optical waveguide 20 and the optical fiber guide member 30 are built up on the surface of the substrate 11 where the adhesive layer 14 is formed.
First, a clad layer is laminated on the entire surface of the substrate 11 with the adhesive layer 14 and patterned to form the lower clad layer 21 and the lower clad layer 31 (FIGS. 5 (d), 6 (d), and 6 FIG. 7 (d) and FIG. 8 (d)). The lower cladding layer 21 covers substantially half of the substrate 11 with the adhesive layer 14 in the Y direction. As shown in FIG. 8 (d), the lower clad layer 31 covers only the vicinity of the edges on both sides in the X direction in the portion of the substrate 11 with the adhesive layer 14 where the lower clad layer 21 is not formed.

Next, a core layer is laminated on the substrate 1 with the adhesive layer 14 on which the lower clad layers 21 and 31 are formed, and patterned to form an optical signal transmission core pattern 22 and an optical fiber guide core pattern 32 (first). FIG. 5 (e), FIG. 6 (e), FIG. 7 (e), FIG. 8 (e), FIG. 9).
Four optical signal transmission core patterns 22 are formed on the lower cladding layer 21. These optical signal transmission core patterns 22 have a rectangular parallelepiped shape extending in the Y direction, and are arranged in parallel with an interval in the X direction.
Five optical fiber guide core patterns 32 are formed on the substrate 11 with the adhesive layer 14. These optical fiber guide core patterns 32 have a rectangular parallelepiped shape extending in the Y direction, and are arranged in parallel with an interval in the X direction. The two optical fiber guide core patterns 32 on both ends in the X direction respectively cover a part of the upper surface of the lower cladding layer 31. An optical fiber mounting groove 38 is formed between these optical fiber guide core patterns 32. These optical fiber guide core patterns 32 are for fixing the optical fiber 50 and do not function as a core for transmitting optical signals.
As shown in FIG. 9, the optical signal transmission core pattern 22 and the optical fiber guide core pattern 32 are arranged at positions shifted in the X direction, and the end face of the optical signal transmission core pattern 22 is mounted on the optical fiber. It faces the groove 38.

Next, a clad layer 23a is laminated on the substrate 11 with the adhesive layer 14 on which the lower clad layers 21 and 31 and the core patterns 22 and 32 are formed (FIG. 5 (f)), and patterned to form the upper clad layer 23 and An upper cladding layer 33 (FIG. 8 (f)) is formed (FIGS. 6 (f), 7 (f) and 8 (f)).
The upper clad layer 23 is formed on the upper surface of the lower clad layer 21 so as to cover the optical signal transmission core pattern 22. On the other hand, the upper cladding layer 33 is formed so as to cover a part of the two optical fiber guide core patterns 32 on both sides in the X direction, as shown in FIG. That is, the upper clad layer 33 covers an outer side surface in the X direction and a part of the upper surface of the two optical fiber guide core patterns 32.

  In the processes (1) to (3), the patterning method of the lower clad layers 21 and 31, the core patterns 22 and 32, and the upper clad layers 23 and 33 is the patterning of the core pattern in the first embodiment. It is the same as the method. Further, the materials, dimensions, formation methods, and the like of the substrate 11, the lower cladding layers 21 and 31, the core patterns 22 and 32, and the upper cladding layers 23 and 33 are the substrate 1 and the lower cladding in the first embodiment, respectively. Basically the same as the layer 2, the core pattern 3 and the upper cladding layer 4. Therefore, in the following, the points of these members that are different from the first embodiment will be described. For convenience of explanation, a method for fixing the optical fiber 50 to the optical fiber mounting groove 38 will be described first before explaining each of these members.

A method for fixing the optical fiber 50 to the optical fiber mounting groove 38 is not particularly limited as a method for fixing the optical fiber 50 to the optical fiber mounting groove 38 of the optical fiber guide member 30, for example, so as not to be placed on the optical waveguide 20. The glass block is aligned, the optical fiber 50 is held by the glass block and pushed into the optical fiber mounting groove 38, the center of the optical signal transmitting core pattern 22 and the center of the optical fiber 50 are aligned, and fixed with an adhesive or the like. Just do it. When the distance from the bottom surface of the optical fiber mounting groove 38 to the upper surface of the optical waveguide 20 is equal to or smaller than the diameter of the optical fiber 50, the glass block is applied to the optical waveguide 20 (so as not to be exposed to the photosensitive resin layer 7). You may align. At this time, it arrange | positions so that the front end surface of the optical fiber 50 may contact the part which the core pattern 22 has exposed among the end surfaces (vertical surface) by the side of the optical fiber guide member 30 of the optical waveguide 20. FIG.
At this time, alignment in the X direction can be performed by the optical fiber guide core pattern 32, and alignment in the Z direction can be performed by the substrate 11 with the adhesive layer 14.

Lower clad layer The lower clad layers 21 and 31 have a cured film thickness of [(radius of the optical fiber 50) − (lower clad layer] for the purpose of aligning the center of the optical fiber 50 and the optical signal transmission core pattern 22. It is more preferable to use a film having a thickness of the optical signal transmission core pattern 22 formed on the thickness 21/2).
A specific example shows a preferable thickness of the lower cladding layer 21 when an optical fiber 50 having a diameter of 80 μm and a core diameter of 50 μm is used. First, when the optical signal propagates from the optical fiber to the optical signal transmission core pattern, a square circumscribing the core diameter of the optical fiber can propagate without optical loss. In this case, the core of the optical waveguide 20 is 50 μm × 50 μm (core height: 50 μm). Applying the above equation, the optimum thickness of the lower cladding layer 21 is 15 μm. Further, when an optical signal propagates from the optical fiber 50 to the optical signal transmission core pattern 22 using the same optical fiber as described above, a square inscribed in the core diameter of the optical fiber 50 can propagate without optical loss. In this case, the core of the optical waveguide 20 is 40 μm × 40 μm (core height: 40 μm). Applying the above formula, the optimum thickness of the lower cladding layer 21 is 20 μm.

Optical fiber guide core pattern The height from the surface of the adhesive layer 14 to the upper surface of the optical fiber guide core pattern 32 (the thickness of the optical fiber guide core pattern 32) is not less than the radius and not more than the diameter of the optical fiber 50. It is preferable.
If the height from the surface of the adhesive layer 14 to the upper surface of the optical fiber guide core pattern 32 is equal to or greater than the radius of the optical fiber 50, the optical fiber 50 is less likely to be displaced. Fixing of the fiber 30 is facilitated. 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 order to obtain the thickness, for example, the thickness of the film for forming the core layer may be appropriately adjusted.
Further, as the lateral width of the optical fiber mounting groove 38 constituting between the optical fiber guide core patterns 32, it is sufficient that the width is equal to or larger than the diameter of the optical fiber 50. From the viewpoint of mountability and tolerance of the optical fiber 50, The width is preferably 0.1 to 10 μm wider than the diameter of the optical fiber 50.

Optical signal transmission core pattern When the thickness of the optical signal transmission core pattern 22 is transmitted from the optical fiber 50 to the optical signal transmission core pattern 22, the thickness of the optical signal transmission core pattern 22 is less than the core diameter of the optical fiber 50. When light is transmitted from the optical signal transmission core pattern 22 to the optical fiber 50 with little loss, the rectangle formed by the thickness and width of the optical signal transmission core pattern 22 is located inside the core diameter of the optical fiber 50. It is even better to adjust to.

Upper Cladding Layer In the optical waveguide 20, the thickness of the upper cladding layer 23 for embedding the optical signal transmission core pattern 22 (height from the upper surface of the lower cladding layer 21 to the upper surface of the upper cladding layer 23) is particularly limited. However, it is preferable that the thickness be equal to or greater than the thickness of the core pattern 22.
By not forming the upper clad layer 23 on the optical fiber guide core pattern 32 (as shown in FIG. 5 (f), the clad layer 23a may be removed once formed), the height from the surface of the adhesive layer 14 is increased. It becomes easy to make the thickness larger than the radius of the optical fiber 50 and smaller than the diameter. At this time, the thickness is not limited to the thickness of the upper clad layer 23 formed on the optical signal transmission core pattern 22, but from the surface of the adhesive layer 14 to the surface of the upper clad layer 23 formed on the optical signal transmission core pattern 22. The height may be equal to or greater than the diameter of the optical fiber 50.

Optical fiber If the diameter of the optical fiber 50 is 200 micrometers or less, it is preferable from a viewpoint that the film thickness of the resin film for core layer formation is easy to control, and it is still more preferable to use an optical fiber with a 125 micrometers diameter or an 80 micrometers diameter.

(Process A ₂ )
In this step, the notch 24 is formed in the optical waveguide 20 of the optical fiber connector obtained in the optical fiber connector formation step (FIGS. 5 (g) and 6 (g)). In the present embodiment, the slit groove 16 is also formed between the optical waveguide 20 and the optical fiber guide member 30 when the notch 24 is formed. The method of forming the notch 24 and the slit groove 16 is basically the same as in the case of the first embodiment.

Cutout In the present embodiment, one cutout 24 extending in the X direction of the optical waveguide 20 is formed. The cutout portion 24 has a V-shaped cross section perpendicular to the extending direction, and extends over two opposing side surfaces of the optical waveguide 20. The normals of the two side surfaces of each notch 5 are inclined with respect to the extending direction (Y direction) of the core pattern 3. The inclination angle formed between the normal line of the side surface of the notch 5 and the extending direction of the core pattern 3 can be appropriately set according to the use, but is preferably 30 to 60 °, more preferably 40 to 50. °, more preferably 44 to 46 °. However, at least one of the two side surfaces of the cutout portion 24 on the side of the optical fiber guide member 30 may be inclined, and the other side surface may not be inclined (that is, the normal line of the other side surface). May be parallel to the extending direction of the core pattern 3 (Y direction)).
The lower end of the notch 24 only needs to reach at least part of the optical signal transmission core pattern 22, but from the viewpoint of reducing optical loss, the lower end of the notch 24 is below the lower surface of the optical signal transmission core pattern 22. Preferably reached.

Slit groove The lower end of the slit groove 16 reaches at least a part of the adhesive layer 14. Thereby, the optical fiber 50 can be mounted horizontally in the optical fiber mounting groove 38. That is, in the state of FIG. 6 (f), the left side surface of the lower cladding layer 21 is not a complete vertical surface, and the left side surface is an inclined surface that protrudes to the left as it goes down. is there. When the optical fiber 50 is mounted in the optical fiber mounting groove 38 in this state, the end face of the optical fiber 50 may be pushed up to the inclined surface, and the optical fiber 50 may not be horizontal. Therefore, by removing the inclined surface by forming the slit groove 16, the optical fiber 50 can be mounted horizontally in the optical fiber mounting groove.
When the slit groove 16 is formed, a part of the end face of the optical waveguide 20 may be removed. Thereby, the end surface of the optical waveguide 20 becomes a highly accurate vertical surface, and is in good contact with the end surface of the optical fiber 50.

(Process B ₂ )
In this step, a mirror 25 made of a metal layer is formed in the notch 24 (FIGS. 5 (h) and 6 (h)). The method for forming this mirror 25 is the same as that in step B _{1 of the first} embodiment.
In the present embodiment, it is formed on the entire surface of the two side surfaces of the cutout portion 24, but is not limited to this, and at least the core pattern of the side surface of the cutout portion 24 on the optical fiber guide member 30 side. What is necessary is just to form in the part which 22 is exposed.

(Process C ₂ )
In this step, the notch 24 is filled with the photosensitive resin layer 26. Method of filling a notch portion 24 by the photosensitive resin layer 26 is the same as Step C ₂ of the first embodiment.

(Process D ₂ )
In this step, the photosensitive resin layer 26 is patterned, and the photosensitive resin layer 26 other than the notch 24 is removed (FIGS. 5 (i) and 6 (i)). This removal method is the same as step D1 of the _first embodiment.
The range in which the photosensitive resin layer 26 is left may be left as long as it does not cover the optical fiber mounting groove 38. Thereby, the optical fiber 50 can be satisfactorily mounted in the optical fiber mounting groove 38.

  As described above, the mirrored optical fiber connector 40 can be manufactured. The obtained optical fiber connector 40 with a mirror can reduce the thickness of a portion where the photosensitive resin layer 26 is not formed. In addition, by removing portions of the photosensitive resin layer 26 other than the notch 24 and the vicinity thereof, the photosensitive resin layer 26 does not remain in the optical fiber mounting groove 38, and the optical fiber mounting is performed. The optical fiber 50 can be satisfactorily mounted in the groove 38.

[Third embodiment (manufacturing method of flexible optical waveguide with mirror)]
Hereinafter, a manufacturing method of the flexible optical waveguide with a mirror according to the third embodiment will be described with reference to the drawings. FIG. 10 is a cross-sectional view for explaining a method for producing a flexible optical waveguide with a mirror.
The manufacturing method of the flexible optical waveguide with a mirror according to the present embodiment is basically the first except that the electric wiring board in which the metal wiring 103 is formed on the lower surface of the substrate 101 is used instead of the substrate 1. This is the same as the manufacturing method of the optical waveguide with a mirror according to the embodiment.

(Metal wiring formation process)
In this step, the metal wiring 103 is formed on the lower surface of the substrate 101. The metal wiring 103 can be formed by forming the metal layer 102 on the lower surface of the substrate 101 by a conventional method and etching the metal layer 102 (FIGS. 10A to 10B). The details of the metal wiring forming process are as described in the second embodiment. In this embodiment, a coverlay film 104 for protecting the electrical wiring 103 is further formed on the metal wiring 103.

(Optical waveguide forming step (FIGS. 10 (a) to (f))
In the present embodiment, the optical waveguide 8 is built up on the substrate 1. The method for forming the optical waveguide 8 is the same as that in the first embodiment.

(Process A ₃ (FIG. 10 (g))
This step is the same as that in Step A _1.
(Process B ₃ (FIG. 10 (h))
This step is the same as that in Step B _1.
(Process C ₃ )
This step is the same as that in Step C _1.
(Process D ₃ (FIG. 10 (i))
In this step, the photosensitive resin layer 7 is patterned, and at least a part of the photosensitive resin layer 7 in the bent portion 8a of the flexible optical waveguide 8 is removed. This removal process is the same as the above Step D _1.

  The flexible optical waveguide 9 with a mirror can be manufactured as described above. The obtained flexible optical waveguide 9 with a mirror can reduce the thickness of the portion where the photosensitive resin layer 7 is not formed. In addition, the central portion of the flexible optical waveguide 9 with a mirror where the photosensitive resin 7 is not formed can be easily bent by the bent portion 8a (FIG. 10 (i)).

[Modification]
The above embodiment is an example of the present invention, and the present invention is not limited to the above embodiment.
For example, in the first and third embodiments, the same adhesive layer 14 as in the second embodiment may be formed on the substrates 1 and 101, and the optical waveguide 8 may be formed on the adhesive layer 14. In the second embodiment, the adhesive layer 14 may be omitted.

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]
(1) Production of (A) base polymer; (meth) acrylic polymer (A-1) 46 mass of propylene glycol monomethyl ether acetate in a flask equipped with a stirrer, cooling tube, gas introduction tube, dropping funnel and thermometer And 23 parts by mass of methyl lactate were weighed 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.

(2) Measurement of weight average molecular weight GPC (“SD-8022”, “DP-8020”, and “RI-8020” manufactured by Tosoh Corporation)) is used as the weight average molecular weight (converted to standard polystyrene) of (A-1). It was 3.9 * 10 < ⁴ > as a result of using and measuring. The column used was “Gelpack GL-A150-S” and “Gelpack GL-A160-S” manufactured by Hitachi Chemical Co., Ltd.

(3) Measurement of acid value As a result of measuring the acid value of A-2, it was 79 mgKOH / g. The acid value was calculated from the amount of 0.1 mol / L potassium hydroxide aqueous solution required to neutralize the A-2 solution. At this time, the point at which the phenolphthalein added as an indicator changed color from colorless to pink was defined as the neutralization point.

(4) Preparation of Cladding Layer Forming Resin Varnish (A) As a base polymer, 84 parts by mass of the A-1 solution (solid content 45 mass%) (solid content 38 mass parts), (B) As a photocuring component, polyester 33 parts by mass of urethane (meth) acrylate having a skeleton ("U-200AX" manufactured by Shin-Nakamura Chemical Co., Ltd.) and urethane (meth) acrylate having a polypropylene glycol skeleton ("UA-" manufactured by Shin-Nakamura Chemical Co., Ltd.) 4200 "), 15 parts by mass, (C) polyfunctional block isocyanate solution in which isocyanurate type trimer of hexamethylene diisocyanate is protected with methyl ethyl ketone oxime as a thermosetting component (solid content 75% by mass) (Suika Bayer Urethane Co., Ltd.) ) "Sumijoule BL3175") 20 parts by mass (solid content 15 parts by mass), (D) photopolymerization started As an agent, 1 part by mass of 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (“Irgacure 2959” manufactured by Ciba Japan Co., Ltd.), bis 1 part by weight of (2,4,6-trimethylbenzoyl) phenylphosphine oxide (“Irgacure 819” manufactured by Ciba Japan Co., Ltd.) and 23 parts by weight 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 was applied onto the non-treated surface of a PET film (“Cosmo Shine A4100” manufactured by Toyobo Co., Ltd., thickness 50 μm) using the coating machine. After drying at 20 ° C. for 20 minutes, a surface release-treated PET film (“Purex A31” manufactured by Teijin DuPont Films, Inc., thickness 25 μm) was applied as a cover film 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. In this example, the thickness of the lower clad layer used as the lower clad layer and the adhesive layer is used. 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 upper clad layer forming resin film 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 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 pasted as a cover film so that the release surface is on the resin side, and a core layer forming resin A film was obtained. At this time, the thickness of the resin film can be arbitrarily adjusted by adjusting the gap of the coating machine. In this example, the thickness of the resin film for forming the core layer used 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.

[Preparation of Optical Waveguide with Mirror] FIGS. 1 to 2 An optical fiber connector with a mirror in which the adhesive layer 14 is omitted in FIGS. 1 to 2 was prepared by the following procedure.

(Production of optical waveguide)
A polyimide film (polyimide; Upilex RN (manufactured by Ube Nitto Kasei), thickness: 25 μm) is cut into a size of 100 × 100 μm as the substrate 1, and the 15 μm-thick lower cladding layer obtained above is formed on the substrate 1. The resin film is cut to a size of 100 × 100 μm, the cover film is peeled off, and vacuum-pressurized laminator (manufactured by Meiki Seisakusho Co., Ltd., MVLP-500) is used as a flat plate laminator, and vacuumed to 500 Pa or less, The clad layer was laminated by thermocompression bonding under conditions of a pressure of 0.4 MPa, a temperature of 100 ° C., and a pressing time of 30 seconds. Next, UV light (wavelength 365 nm) is irradiated at 4 J / cm ² from the carrier film side with an UV exposure machine (Oak Seisakusho, EXM-1172), then the carrier film is peeled off, and heat-treated at 170 ° C. for 1 hour. Thus, the substrate 1 with the lower cladding layer 2 having a thickness of 15 μm was formed.

Next, a cover film is formed on the surface of the lower clad layer 2 using a roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.) under the conditions of pressure 0.4 MPa, temperature 50 ° C., and laminating speed 0.2 m / min. The core layer-forming resin film having a thickness of 50 μm was laminated, and then vacuumed to 500 Pa or less using the above-described vacuum pressure laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.). Thermocompression bonding was performed under the conditions of 4 MPa, a temperature of 70 ° C., and a pressing time of 30 seconds. Thereafter, ultraviolet light (wavelength 365 nm) was irradiated with 700 mJ / cm ² with the above-described ultraviolet exposure machine through a negative photomask having a core pattern width of 50 μm for optical signal transmission, followed by heating at 80 ° C. for 5 minutes. Thereafter, the PET film as the carrier 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). Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (s), and the optical signal transmission core pattern 3 was formed.

Next, the upper cladding layer resin film having a thickness of 52 μm from which the cover 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. Next, UV light (wavelength 365 nm) is irradiated at 4 J / cm ² from the carrier film side with an UV exposure machine (Oak Seisakusho, EXM-1172), then the carrier film is peeled off, and heat-treated at 170 ° C. for 1 hour. Thus, an optical waveguide 8 having a thickness of 50 μm of the core pattern 3 and a thickness of 10 μm of the upper cladding layer 4 formed on the upper portion of the core pattern 3 was formed.

(Formation of optical path conversion mirror)
A 45 ° cutout 5 was formed using a dicing saw (DAC552, manufactured by Disco Corporation) from the upper clad layer 4 side of the obtained optical waveguide 8. Next, a metal mask having an opening at the mirror forming portion was placed on an optical fiber connector with a mirror, and Au was vapor-deposited by 0.5 μm as a mirror 6 made of a metal layer using a vapor deposition apparatus (RE-0025, manufactured by First Giken). (See FIGS. 1-6).

(Filling and patterning of notches)
A 65 μm thick upper clad layer resin film from which the cover film is peeled off as a photosensitive resin layer from the cutout portion 5 formation side of the obtained optical waveguide 8 is formed from the above-described vacuum pressure laminator (trade name) After evacuating to 500 Pa or less using MVLP-500) manufactured by Kikai Seisakusho, the film was laminated by thermocompression bonding under conditions of a pressure of 0.4 MPa, a temperature of 110 ° C., and a pressurization time of 30 seconds. Next, ultraviolet light (wavelength 365 nm) is 250 mJ / cm ² from the carrier film side using a negative photomask that is opened with an ultraviolet exposure machine (EXM-1172 manufactured by Oak Manufacturing Co., Ltd.) so that the mirror 6 formation region is on the inside. Then, the carrier film was peeled off, and the photosensitive resin layer 7 was etched using a developer (1% aqueous sodium carbonate solution). Subsequently, it was washed with water, dried by heating at 170 ° C. for 1 hour and cured to form an optical waveguide 9 with a mirror. As a result, an optical waveguide 9 in which the height from the bottom surface of the substrate 1 to the surface of the upper cladding layer 4 was 100 μm and the notch portion 5 was filled with the photosensitive resin 7 was obtained.
Next, when the outer shape was processed using a dicing saw (DAC552, manufactured by Disco Corporation) with a width of 1 mm in the direction of the core pattern 3 of the obtained optical waveguide 9, the mirror 6 was not peeled off.

Example 2
The optical fiber connector with a mirror shown in FIGS. 2 to 9 was produced by the following procedure.
[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) Using a roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.) with a photosensitive dry film resist (trade name: Photec, manufactured by Hitachi Chemical Co., Ltd., thickness: 25 μm) on the copper foil surface of the pressure 0.4 MPa The film was applied under the conditions of a temperature of 110 ° C. and a laminating speed of 0.4 m / min, and then passed through a negative photomask having a width of 50 μm from the photosensitive dry film resist side with an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). Irradiate ultraviolet light (wavelength 365 nm) at 120 mJ / cm ² to form a photosensitive dry film resist in an unexposed portion. 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, and an electrical wiring (metal wiring) 103 was formed.

(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, a substitution gold plating solution (100 mL; HGS-500 and 1.5 g; a bath with potassium gold cyanide / L) (trade name: HGS-500, manufactured by Hitachi Chemical Co., Ltd.) at 85 ° C. for 8 minutes. Immersion was performed to form a 0.06 μm displacement gold film on the Ni film. Thereby, the electric wiring board 50 in which the portion of the electric wiring 103 without the coverlay film was covered with the plating of Ni and Au was obtained.

The 10 μm-thick clad layer-forming resin film obtained above is cut into a size of 100 × 100 mm, the release PET film (Purex A31) as the cover film is peeled off, and the flexible wiring board polyimide formed as described above Using a vacuum pressure laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) as a flat plate type laminator on the surface, evacuating to 500 Pa or less, then pressure 0.4 MPa, temperature 100 ° C., pressurization time 30 seconds The adhesive layer 14 was formed by thermocompression bonding. Next, ultraviolet rays (wavelength 365 nm) are irradiated from the carrier film side at 4 J / cm ² with an ultraviolet exposure machine (manufactured by Oak Manufacturing Co., Ltd., EXM-1172), and then the carrier film is peeled off, followed by heat treatment at 170 ° C. for 1 hour. Thus, a substrate 11 with an adhesive layer having a thickness of 10 μm was formed.

[Fabrication of optical fiber connector]
The 15 μm-thick lower clad layer-forming resin film obtained above was cut into a size of 100 × 100 μm, the cover film was peeled off, and laminated on the surface of the adhesive layer 14 with a vacuum laminator under the same conditions as described above. . Through a negative photomask having a non-exposed portion of 850 μm × 3.0 mm, irradiated with ultraviolet rays (wavelength 365 nm) from the carrier film side with an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.) at 250 mJ / cm ^2. did. Thereafter, the carrier film was peeled off, and the lower cladding layers 21 and 31 were etched using a developer (1% aqueous sodium carbonate solution). Subsequently, the substrate 11 with the lower clad layers 21 and 31 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. Thereby, the lower clad layer 3 is formed in the portion where the optical waveguide 20 is formed, and the lower clad layers 21 and 31 are not present in the portion where the optical fiber mounting groove 38 is formed.

Next, roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd., HLM-1500) is used on the lower clad layers 21 and 31, and the pressure is 0.4 MPa, the temperature is 50 ° C., and the lamination speed is 0.2 m / min. After laminating the 50 μm-thick core layer-forming resin film from which the cover film has been peeled off, the vacuum pressure laminator (manufactured by Meiki Seisakusho Co., Ltd., MVLP-500) is used to evacuate to 500 Pa or less. Thermocompression bonding was performed under the conditions of 0.4 MPa, a temperature of 70 ° C., and a pressing time of 30 seconds. Then, through a negative photomask having an optical signal transmission core pattern width of 50 μm (pattern pitch: 125 μm, 4 lines) and a non-exposed portion width of 85 μm (pattern pitch: 125 μm, 4 lines) for forming the optical fiber mounting groove 38. The optical signal transmission core pattern 22 is formed on the lower clad layer 21, and the optical fiber mounting groove 38 formed by the optical fiber guide core pattern 32 is formed on the substrate 11 (adhesive layer 14 and lower clad layer 31). After aligning as described above, ultraviolet rays (wavelength 365 nm) were irradiated with 700 mJ / cm ² with the above-described ultraviolet exposure machine, and then after exposure at 80 ° C. for 5 minutes, heating was performed. Thereafter, the PET film as the carrier 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 22 and the optical fiber guide core pattern 32. At the same time, a groove 38 having a width of 85 μm is formed. It was. The size of each pattern in the optical fiber guide core pattern 32 is such that the optical fiber can transmit an optical signal to the optical signal transmission core pattern 22 when the optical fiber is fixed to the optical fiber mounting groove 38. Designed to join.

Next, after the upper cladding layer resin film having a thickness of 54 μm from which the cover 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 the negative photomask used for the lower clad layer 3, after irradiating ultraviolet rays (wavelength 365 nm) with 150 mJ / cm ² , the carrier film is peeled off, and using a developer (1% aqueous potassium carbonate solution), The resin film for forming the upper clad layer in the fiber mounting groove 38 was etched. 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, an optical fiber diameter of 80 μm, and four channels.

  In the obtained optical fiber connector, the lateral width of the groove 38 of the optical fiber guide core pattern 32 was 85 μm, the height of the optical fiber guide core pattern 32 was 64 μm, and the thickness of the optical signal transmission core pattern 22 was 49 μm. .

(Slit groove formation)
In order to smooth the optical fiber connection end face of the obtained optical waveguide 20, a slit groove 16 having a width of 40 μm was formed using a dicing saw (DAC552, manufactured by Disco Corporation).

(Formation of optical path conversion mirror)
A 45 ° cutout portion 24 was formed from the upper clad layer 23 side of the obtained optical waveguide 20 using a dicing saw (DAC552, manufactured by Disco Corporation). 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 to a thickness of 0.5 μm as a mirror 25 made of a metal layer using a vapor deposition apparatus (RE-0025, manufactured by First Giken). .

(Filling and patterning of notches)
A 65 μm thick upper clad layer resin film from which the cover film was peeled off as the photosensitive resin layer 26 from the cutout portion 24 forming side of the obtained optical waveguide 20 was applied to the above-described vacuum pressure laminator (Co., Ltd.) from the core pattern forming surface side. Using MVLP-500) manufactured by Meiki Seisakusho, vacuuming was performed to 500 Pa or less, and then thermocompression bonding was performed under the conditions of a pressure of 0.4 MPa, a temperature of 110 ° C., and a pressurization time of 30 seconds to laminate. Next, ultraviolet rays (wavelength 365 nm) are 250 mJ / cm ² from the carrier film side using a negative photomask in which the optical fiber mounting groove 38 is a non-exposed portion with an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). After irradiation, the carrier film was peeled off, and the photosensitive resin layer 26 was etched using a developer (1% aqueous sodium carbonate solution). Subsequently, it was washed with water, dried and cured at 170 ° C. for 1 hour, and an optical fiber connector with a mirror was formed. At this time, there was no remaining photosensitive resin 26 filled with the notch 24 in the optical fiber mounting groove 38.

(Outline processing)
Using a dicing saw (DAC552, manufactured by DISCO Corporation), the substrate is cut parallel to the optical fiber guide core (3 mm from the end face of the optical waveguide), and the outer shape processing is performed so that the optical fiber mounting groove 8 appears on the end face of the substrate. As a result, the mirror 25 did not peel off.
In the optical fiber mounting groove 38 of the optical fiber connector obtained as described above, a 125 μm pitch, 4-channel optical fiber 50 (core diameter: 50 μm, clad diameter: 80 μm) is suppressed by a glass block and the optical fiber mounting groove. As a result, the optical signal was transmitted from the optical fiber 50 by being bonded to the optical transmission surface of the optical signal transmission core pattern 22 of the optical waveguide 20.

Example 3
In Example 2, after the electrical wiring 103 was formed by etching, a coverlay film (trade name: Nikaflex CISG, manufactured by Nikkan Kogyo Co., Ltd., polyimide thickness: 12.5 μm, adhesive thickness: 15 μm) was electrical wiring. 103 is exposed so that both end portions (5.0 mm) are exposed, vacuum-pressed under conditions of a pressure of 4.0 MPa, a temperature of 160 ° C. and a pressurization time of 90 minutes, and the coverlay film 104 for protecting the electrical wiring 103 is formed. Provided (see FIG. 3-3). Thereafter, Ni / Au plating was performed in the same manner as in Example 2 to obtain an electric wiring board with a coverlay film.
Next, an optical waveguide 20 with a notch 24 having a mirror 25 made of a metal layer was formed on the polyimide surface opposite to the electrical wiring 103 of the obtained electrical wiring board by the same method as in Example 1. .

Thereafter, a 65 μm-thick core layer resin film having a cover film peeled off as the photosensitive resin layer 26 from the cutout portion 24 side of the obtained optical waveguide 20 is applied to the above-described vacuum pressure laminator (stock) The product was evacuated to 500 Pa or less using a company name “Miki Seisakusho, MVLP-500” and then thermocompression bonded under the conditions of a pressure of 0.4 MPa, a temperature of 110 ° C., and a pressurization time of 30 seconds for lamination. Next, UV (wavelength 365 nm) was irradiated with 700 mJ / cm ² from the carrier film side using a negative photomask having a bent portion as a non-exposed portion with an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.), then Heating was performed after exposure at 80 ° C. for 5 minutes. Thereafter, the PET film as the carrier 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). Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (s), and the flexible photoelectric composite board | substrate with a flexible optical waveguide was obtained.
When the obtained flexible photoelectric composite substrate was slid at a bending radius of 2 mm and a speed of 2 times / s with the surface of the optical waveguide 20 facing inward, it was broken at 80,000 times.

Comparative Example 1
In Example 1, an optical waveguide was formed by the same method except that the notch 5 was not filled with the photosensitive resin 7. When the outer shape of the obtained optical waveguide was processed in the same manner as in Example 1, the mirror 6 was peeled off.

Comparative Example 2
In Example 2, an optical fiber connector was formed by the same method except that the notch 24 was not filled with the photosensitive resin 26. The outer shape of the obtained optical waveguide 20 was processed in the same manner as in Example 2, and the mirror 25 was peeled off.
In addition, the clad layer forming resin varnish was filled in the cutout portion 24 using a dropper and thermally cured at 170 ° C. for 1 h. The varnish remained in the optical fiber mounting groove 38 and the optical fiber 50 could not be mounted. .

Comparative Example 3
In Example 3, a flexible photoelectric composite substrate with a flexible optical waveguide was formed by the same method except that the notch 24 was filled with the photosensitive resin 26 and was not patterned. When the obtained flexible optoelectric composite substrate was slid at a bending radius of 2 mm and a speed of 2 times / s with the optical waveguide surface inside, it was broken 3000 times.

As described above in detail, according to the present invention, the optical waveguide with a mirror that is small in thickness and can protect the mirror portion, the flexible optical waveguide that can maintain high flexibility in addition to the reduction in thickness and protection of the mirror portion, In addition, it is possible to manufacture an optical fiber connector in which an optical fiber can be satisfactorily introduced into an optical fiber mounting groove without the filling material of the notch flowing into a portion other than the notch such as the optical fiber mounting groove. Is possible.
Therefore, it is useful as an optical waveguide for optical elements, a photoelectric conversion substrate for optical fibers, a flexible optical waveguide, a flexible photoelectric composite substrate, and the like.

1, 11, 101 Substrate 2, 21, 31 Lower clad layer 3, 22, 32 Core pattern 4, 23, 33 Upper clad layer 5, 24 Notch 6, 25 Mirror 7, 26 Photosensitive resin 8, 20 Optical waveguide 8a Bent part 9 Optical waveguide with mirror 14 Adhesive layer 38 Optical fiber mounting groove

Claims (12)

An optical waveguide having a lower clad layer, an optical signal transmission core pattern, and an upper clad layer; an optical path changing notch provided in the optical waveguide; and an optical path changing mirror present in the notch; A method of manufacturing an optical waveguide with a mirror, comprising:
Forming an optical waveguide in which the optical signal transmitting core pattern is formed , X ₁ ;
As the optical path of the optical signal transmitted through said optical signal transmitting core pattern is converted, step A ₁ for forming the cutout portion in the optical waveguide,
Step B ₁ of forming the mirror made of a metal layer in the notch,
A step C ₁ of filling the notch with a photosensitive resin layer; and
As the mirror is protected by the photosensitive resin layer, wherein patterning the photosensitive resin layer, a step D ₁ to remove at least a portion of the photosensitive resin layer other than the notch Manufacturing method of optical waveguide with mirror.   The method for producing an optical waveguide with a mirror according to claim 1, wherein the photosensitive resin layer is made of the same material as at least one of the lower cladding layer, the core pattern, and the upper cladding layer.   An optical waveguide with a mirror manufactured by the method according to claim 1. A substrate, and an optical waveguide with a mirror and an optical fiber guide member arranged side by side on the substrate,
The optical waveguide with a mirror exists in an optical waveguide having a lower clad layer, an optical signal transmission core pattern, and an upper clad layer, an optical path changing notch provided in the optical waveguide, and the notch And an optical path changing mirror
The optical fiber guide member has an optical fiber mounting groove for fixing the optical fiber,
The optical fiber guide member and the optical fiber fixed to the optical fiber mounting groove of the optical fiber guide member and the optical signal transmission core pattern of the optical waveguide are positioned so as to be able to transmit and receive optical signals. A method of manufacturing an optical fiber connector with a mirror in which optical waveguides are juxtaposed,
Forming an optical waveguide having the optical signal transmission core pattern formed thereon X ₂ ;
As the optical path of the optical signal transmitted through said optical signal transmitting core pattern is converted, step A ₂ for forming the cutout portion in the optical waveguide,
Step B ₂ of forming the mirror made of a metal layer in the notch,
Filling the notch with a photosensitive resin layer C ₂ , and
As the mirror is protected by the photosensitive resin layer, wherein patterning the photosensitive resin layer, it mirrored light having a step D ₂ of removing at least the photosensitive resin layer of the optical fiber mounting groove Manufacturing method of fiber connector.   The method for manufacturing an optical fiber connector with a mirror according to claim 4, wherein the substrate is an electric wiring board.   The method of manufacturing an optical fiber connector with a mirror according to claim 4 or 5, wherein the photosensitive resin layer is made of the same material as at least one of the lower cladding layer, the core pattern, and the upper cladding layer.   The optical fiber connector with a mirror manufactured by the method in any one of Claims 4-6. A flexible optical waveguide having a lower clad layer, an optical signal transmission core pattern, an upper clad layer, an optical path changing notch provided in the flexible optical waveguide, and an optical path changing mirror present in the notch A method of manufacturing a flexible optical waveguide with a mirror,
Forming a flexible optical waveguide having the optical signal transmission core pattern formed thereon X ₃ ;
Said optical signal so that the optical path is converted in transmitting core pattern optical signal transmitted through the step A ₃ for forming the notch in the flexible optical waveguide,
Step B ₃ of forming an optical path changing mirror made of a metal layer in the notch,
Filling the notch with a photosensitive resin layer C ₃ , and
Step D ₃ of patterning the photosensitive resin layer so that the mirror is protected by the photosensitive resin layer, and removing at least a part of the photosensitive resin layer at the bent portion of the flexible optical waveguide. Of manufacturing a flexible optical waveguide with a mirror. After performing an adhesive layer forming step of forming an adhesive layer on the substrate to form a substrate with an adhesive layer, and an optical waveguide forming step of forming the flexible optical waveguide on the adhesive layer of the substrate with the adhesive layer The method for producing a flexible optical waveguide with a mirror according to claim 8, wherein the steps A _{3 to} D ₃ are performed.   The method for manufacturing a flexible optical waveguide with a mirror according to claim 9, wherein the substrate is an electric wiring board.   The method for producing a flexible optical waveguide with a mirror according to claim 8, wherein the photosensitive resin layer is made of the same material as at least one of the lower cladding layer, the core pattern, and the upper cladding layer.   The flexible optical waveguide with a mirror manufactured by the method in any one of Claims 8-11.