JP2012063468A - Manufacturing method of optical waveguide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an optical waveguide that suppresses a decrease in propagation loss of the optical waveguide, improves visibility of an alignment mark, and has superior productivity.SOLUTION: An undercladding layer 1, a core 2, and an alignment mark 1a are formed on a surface of a metallic substrate 10. In the manufacturing method of the optical waveguide, a molding tool M is prepared which has recesses 21 formed and also has alignment marks 22, corresponding to the alignment marks 1a, formed. When the metallic substrate 10 and the molding tool M are positioned based upon the pairs of alignment marks 1a, 22, irradiation with light from the side of the molding tool M is carried out, and irradiation light is used to achieve the positioning. Then, an overcladding layer 3 is formed in a state in which the core 2 is coated. The undercladding layer 1 contains a dye which absorbs light of 400-700 nm in wavelength, and has an absorbance of 0.24 or more to the light for the positioning of 400-700 nm in wavelength.

Description

  The present invention relates to a method of manufacturing an optical waveguide widely used in optical communications, optical information processing, position sensors, and other general optics.

  The optical waveguide is usually configured by forming a core, which is a light path, in a predetermined pattern on the surface of the under cladding layer, and forming an over cladding layer in a state of covering the core. In order to improve the mass productivity of such optical waveguides, manufacturing by a roll-to-roll process has been carried out, and as a base material that can withstand the stress (curing shrinkage) associated with the curing of various resins as the forming material There is a tendency to use a metal substrate such as stainless steel (SUS).

  SUS is an inexpensive material that can suppress warping due to shrinkage stress of the coating film, but it is a metal and its surface is a fine rough surface, which causes light scattering reflection in the exposure process in core formation. However, the wall surface of the core may be roughened. For this reason, for example, a technique has been proposed in which the back reflection of a metal substrate such as SUS is suppressed by introducing an ultraviolet absorber into the underclad layer forming material (see Patent Document 1).

  In this type of optical touch panel using an optical waveguide, the light emitting part and the incident part are formed in a lens shape in the overcladding layer, and thus it is necessary to produce the optical touch panel by an imprint process manufacturing method. At that time, in order to improve the positional accuracy between the end of the core that emits light and the overcladding layer (lens), an alignment mark is prepared on the core in advance and the core and overcladding are recognized while recognizing the alignment mark using an alignment camera. The process of aligning the layers and bonding them together is essential (see Patent Document 2).

JP 2009-276724 A JP 2008-20343 A

  In the conventional optical waveguide manufacturing process, the light source used for the alignment camera is one that emits light in the visible light region (wavelength 400 to 700 nm), and SUS is generally used as the metal substrate. Therefore, the surface roughness of SUS is reflected on the alignment camera. For this reason, for example, the contrast of the edge portion of the alignment mark provided in the core is lowered, and as a result, there is a problem that the detection accuracy of the alignment mark by the alignment camera is deteriorated. For such a problem, for example, rounding of the edge by halftone mask exposure is proposed in forming the alignment mark, and an improvement has been proposed in which the degree of recognition is improved by clarifying the contrast. However, it is not a direct solution to the reflection due to the rough surface of the SUS surface, which is the root cause, and the alignment mark formation by the halftone mask exposure method has a low accuracy of the completion. The situation is that it is not fully satisfactory in terms of improving the recognition of the mark, and has led to a deterioration in production efficiency (yield).

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for producing an optical waveguide that suppresses a decrease in propagation loss of the optical waveguide, improves the visibility of the alignment mark, and is excellent in productivity. And

  In order to achieve the above object, an optical waveguide manufacturing method according to the present invention includes a step of forming an underclad layer on the surface of a metal substrate, a step of patterning a core on the surface of the underclad layer, and the underclad layer. Forming an alignment mark at a predetermined position, a recess having a mold surface corresponding to the shape of the over clad layer is formed, and an alignment mark corresponding to the alignment mark formed on the under clad layer is formed at the predetermined position. A step of preparing a mold, and the mold facing the metal substrate on which the core and the under cladding layer are formed, and aligning the metal substrate and the mold with reference to the corresponding pair of alignment marks. When performing the alignment, irradiation is performed with light having a wavelength of 400 to 700 nm from the mold side, and alignment is performed using the irradiation light. And a step of forming an overcladding layer in a state of covering the core, wherein the undercladding layer contains a dye that absorbs light having a wavelength of 400 to 700 nm and is used for the alignment. It has a configuration in which it has a property of absorbance 0.24 or more with respect to light of ˜700 nm.

  In order to solve the problem that the surface roughness of SUS is reflected on the alignment camera during alignment using the alignment mark, the detection accuracy of the alignment mark is deteriorated and the manufacturing workability is lowered. We studied earnestly. First, in order to suppress the reflection due to the roughness of the SUS surface, an experiment was conducted in consideration of introducing a dye that absorbs light used in the alignment camera into the under cladding layer. However, the propagation loss of the optical waveguide deteriorates due to the use of the dye to absorb the propagation light in the core. For this reason, the under-cladding layer uses a forming material having a characteristic capable of absorbing the alignment light without deteriorating the propagation loss as the optical waveguide and suppressing the reflection due to the rough surface of the SUS. Is desired. As a result of further studies from this point of view, the present inventor selected and used a dye having absorption characteristics in a wavelength band region distant from the wavelength (about 850 nm) propagating through the optical waveguide. When the undercladding layer is formed so that the absorbance exceeds a specific value, the deterioration of the propagation loss of the optical waveguide due to the introduction of the dye is suppressed, and the reflection due to the rough surface of the SUS is suppressed, thereby improving the visibility of the alignment mark. The present invention has been found.

  That is, normally, in an optical waveguide forming material that requires high transparency, a coloring component that absorbs propagating light in an optical waveguide component (under clad layer, core, over clad layer) is not introduced. It is technical common sense. This is because not only the core through which light directly propagates but also the light propagates while slightly leaking into both cladding layers, which causes deterioration of propagation loss. However, when manufacturing the optical waveguide, in order to reduce the deterioration of the visibility of the alignment mark due to the surface roughness of the SUS that is the metal substrate used being reflected in the alignment camera, the irradiation light from the alignment camera light source used is used. The present inventor has conceived that it is necessary to impart a corresponding light absorption characteristic to the underclad layer. Therefore, as a result of trying various means for providing the light absorption characteristic, the present inventor has obtained a light absorption characteristic in a wavelength band region (400 to 700 nm) distant from the light source wavelength (about 850 nm) of the optical waveguide. When this is added to the undercladding layer forming material and the absorbance of the obtained undercladding layer exceeds a specific value, the reflection of the SUS surface roughness on the alignment camera is suppressed, and the propagation loss of the optical waveguide It is presumed that it has become possible to improve the visibility of the alignment mark while maintaining the above.

  Thus, in the method for producing an optical waveguide of the present invention, the under cladding layer contains a dye that absorbs light having a wavelength of 400 to 700 nm, and has an absorbance of 0. 0 with respect to light having a wavelength of 400 to 700 nm used for alignment. It is formed to have 24 or more characteristics. For this reason, the deterioration of the propagation loss of the optical waveguide due to the introduction of the dye is suppressed. For example, the reflection on the alignment camera due to the roughness of the SUS surface is suppressed, and the visibility of the alignment mark is improved. Therefore, the production yield of the optical waveguide is improved, and excellent productivity is obtained.

(A)-(c) is explanatory drawing which shows the manufacturing method of the optical waveguide of this invention typically. It is explanatory drawing which shows typically the manufacturing method of the optical waveguide of this invention. It is explanatory drawing which shows typically the manufacturing method of the optical waveguide of this invention. It is explanatory drawing which shows typically the manufacturing method of the optical waveguide of this invention. It is sectional drawing which shows typically the optical waveguide obtained by the said manufacturing method.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

《Optical waveguide manufacturing method》
First, the manufacturing method of the optical waveguide will be described in detail.

  First, a flat metal substrate 10 (see FIG. 1A) used for forming the underclad layer 1 is prepared. Examples of the material for forming the substrate 10 include various metals, which have excellent resistance to expansion and contraction against heat. From the viewpoint that various dimensions are substantially maintained at design values in the manufacturing process of the optical waveguide. A substrate is preferred. Moreover, the thickness of the board | substrate 10 is set in the range of 20 micrometers (film shape)-5 mm (plate shape), for example.

  Next, as shown in FIG. 1A, an under cladding layer 1 is formed on the surface of the substrate 10. Examples of a material for forming the under cladding layer 1 include a thermosetting resin or a photosensitive resin. When using the said thermosetting resin, after apply | coating the varnish which the thermosetting resin melt | dissolved in the solvent, it forms in the under clad layer 1 by heating it. On the other hand, when using the said photosensitive resin, after apply | coating the varnish which the photosensitive resin melt | dissolved in the solvent, it forms in the under clad layer 1 by exposing it with irradiation rays, such as an ultraviolet-ray. The thickness of the under cladding layer 1 is set within a range of 5 to 30 μm, for example.

  The greatest feature of the present invention is that a dye is used as a material for forming the under cladding layer 1. As the dye, a dye capable of absorbing light having a wavelength of 400 to 700 nm is used. For example, a yellow dye, a red dye, a green dye, or the like having light absorption characteristics with respect to the wavelength band region, that is, a color index ( CI)) includes yellow dye λmax 440 nm, red dye λmax 515 nm, green dye λmax 689 nm, and the like. Among these, a yellow dye having light absorption characteristics in a wavelength band region (for example, near 400 nm) distant from the wavelength (about 850 nm) propagating through the optical waveguide is preferably used. Specific examples include Plast yellow 8070, Plast red 8630, and Plast green 8620 manufactured by Arimoto Chemical. These may be used alone or in combination of two or more. In the present invention, the dye means a colored substance used for coloring that can be dissolved in a specific solvent such as water, and does not include a pigment insoluble in the solvent.

  The blending amount of the dye is appropriately set so that the absorbance of the under clad layer is in the range described later in consideration of the kind of the dye, the thickness of the under clad layer, and the like.

  The under-cladding layer 1 formed of the material for forming the under-cladding layer 1 must have a light absorbance of 0.24 or more with respect to light having a wavelength of 400 to 700 nm from the viewpoint of alignment mark visibility. . The absorbance is particularly preferably 0.24 to 0.30. That is, if the absorbance is too low, the effect of suppressing the reflection due to the rough surface of the SUS surface cannot be obtained, and the visibility of the alignment mark is lowered. The absorbance is measured as follows, for example. That is, the absorbance of the under cladding layer (standardized to a thickness of 15 μm) produced on the SUS substrate is measured by reflection measurement using an integrating sphere by the visible ultraviolet absorption spectrum.

  Next, as shown in FIG. 1B, a core 2 having a predetermined pattern is formed on the surface of the under cladding layer 1 by photolithography. As a material for forming the core 2, a photosensitive resin excellent in patterning property is preferably used. Examples of the photosensitive resin include acrylic UV curable resins, epoxy UV curable resins, siloxane UV curable resins, norbornene UV curable resins, polyimide UV curable resins, and the like. These are used together. Moreover, the cross-sectional shape of the core 2 is, for example, a trapezoid or a rectangle excellent in patternability. The width of the core 2 is set within a range of 10 to 500 μm, for example. The thickness (height) of the core 2 is set within a range of 25 to 100 μm, for example.

  The core 2 is formed of a material having a higher refractive index than that of the under clad layer 1 and an over clad layer 3 (see FIG. 3) described later, and a high translucency at the wavelength of propagating light. Is used. The adjustment of the refractive index is appropriately increased or decreased by changing at least one of the type and content of organic groups introduced into the resin that is the material for forming the under cladding layer 1, the core 2, and the over cladding layer 3. Can be reduced. For example, the refractive index can be increased by introducing a cyclic aromatic group (such as a phenyl group) into the resin molecule or increasing the content of the aromatic group in the resin molecule. On the other hand, by introducing a linear or cycloaliphatic group (methyl group, norbornene group, etc.) into the resin molecule, or increasing the content of the aliphatic group in the resin molecule, the refractive index can be increased. Can be small.

  Along with the formation of the core 2, alignment marks 1 a are formed at both end portions (see FIG. 1B) which are predetermined positions of the under cladding layer 1. The shape of the alignment mark 1a is not particularly limited as long as it can be visually recognized as the alignment mark. In addition, as a method for forming the alignment mark 1a, for example, a photosensitive resin material (for example, a core 2 forming material) is used and is applied onto the under cladding layer 1 by an applicator and dried. After drying, exposure is performed by irradiating an irradiation beam such as ultraviolet rays through a photomask having a predetermined shape, and then the exposed portion is cured by heat treatment. Next, an unexposed portion is developed by using a developing solution (γ-butyrolactone or the like), washed with water and removed, and dried to form an alignment mark having a predetermined shape.

  On the other hand, as shown in FIG.1 (c), the shaping | molding die M for over clad layer formation is prepared. The mold M is made of, for example, a translucent resin (eg, silicone resin, acrylic resin, epoxy resin) and a translucent support plate G (eg, quartz glass, blue plate glass, polycarbonate, acrylic). Then, by molding using a mold member having the same shape as that of the overcladding layer, the translucent resin can be cured and fixed to the translucent support plate G. . The mold M [see FIG. 1 (c)] has the translucent support plate G fixed to the lower surface of the cured body 20 of the translucent resin, and the upper surface of the cured body 20 of the translucent resin. Two concave portions 21 having a mold surface corresponding to the shape of the over cladding layer 3 are formed, and one end portion (left end portion in FIG. 1C) of each concave portion 21 is formed on the lens curved surface 21a. Yes.

  At both ends of the mold M, alignment marks 22 corresponding to the alignment marks 1a provided on the under cladding layer 1 are provided. The shape of the alignment mark 22 is not particularly limited as long as it is a shape corresponding to the alignment mark 1a provided on the under cladding layer 1, and the formation method thereof is the same as the formation of the alignment mark 1a.

  Next, the mold M is placed on a molding stage (not shown) with the concave portion 21 facing upward, and a liquid that is a material for forming the overcladding layer 3 (see FIG. 5) is disposed in the concave portion 21. The photosensitive resin 3A is filled.

  Next, as shown in FIG. 2, the undercladding layer 1 in which the core 2 is patterned is opposed to the mold M in which the recess 21 is filled with the liquid photosensitive resin 3 </ b> A. At this time, the alignment mark 1a provided on the undercladding layer 1 and the alignment mark 22 provided on the mold M are irradiated with light from the mold M side in the direction of the arrow L using an alignment camera to align the alignment mark 1a. Positioning is performed after confirming that the marks 1a and 22 match. In general, light having a wavelength of 400 to 700 nm in the visible light region is used as the light of the alignment camera.

  Next, as shown in FIG. 3, the core 2 patterned on the surface of the under cladding layer 1 is immersed in a photosensitive resin 3A which is a material for forming the over cladding layer 3. Is positioned with respect to the recess 21 of the mold M, and the under cladding layer 1 is pressed against the mold M.

  The load at the time of positioning and pressing the under-cladding layer 1 against the mold M is set within a range of 49 to 980 N, for example. Here, since the formation part of the recessed part 21 of the said shaping | molding die M is resin, it has a pressure resistance. Therefore, as described above, the undercladding layer 1 can be pressed and brought into close contact with the mold M, and the formation of flash can be prevented.

  Next, as shown in FIG. 4 (shown upside down from FIG. 3), the photosensitive resin 3 </ b> A is irradiated with an irradiation line such as ultraviolet rays through the molding die M, and thereby its photosensitivity. Resin 3A is exposed. Thereby, the photosensitive resin 3A is cured, and the over clad layer 3 having one end portion formed on the lens portion 3a is formed. In the exposure by irradiation with ultraviolet rays or the like, the metal substrate 10 is adsorbed and fixed to a work stage (not shown). The thickness of the over clad layer 3 (thickness from the surface of the under clad layer 1) is set, for example, within a range of 25 to 1500 μm.

  Then, the over clad layer 3 was removed from the mold M together with the metal substrate 10, the under clad layer 1 and the core 2 and formed on the surface of the metal substrate 10 as shown in FIG. An optical waveguide composed of the under cladding layer 1, the core 2, and the over cladding layer 3 is obtained. In this embodiment, two optical waveguides are formed. However, in general, two or more optical waveguides are formed, and when the optical waveguides are used, the individual optical waveguides are cut out to be various types. Served for use.

  Further, before or after the overcladding layer 3 is demolded, heat treatment (for example, about 70 to 90 ° C.) is appropriately performed as necessary. The metal substrate 10 may be peeled from the under cladding layer 1 as necessary.

  In the above embodiment, one end portion of the over clad layer 3 is formed in the lens portion 3a. However, it may be formed in a planar shape as in the other end portion.

《Use of optical waveguide》
The optical waveguide can be used, for example, as a detection means (position sensor) for a touch position of a finger or the like on the touch panel by forming an L-shaped plate. That is, in the L-shaped optical waveguide, a plurality of cores 2 are formed in a pattern extending in parallel from the corners of the L-shaped plate to the inner edge. Two such L-shaped optical waveguides are produced. A light emitting element is optically coupled to the outside of the corner of one optical waveguide, and a light receiving element is optically coupled to the outside of the corner of the other optical waveguide. And if these optical waveguides are installed along the peripheral edge of the screen of the quadrangular display of the touch panel, they can be used as means for detecting the touch position of a finger or the like on the touch panel.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to the examples.

[Example 1]
<Preparation of varnish for underclad layer formation>
To 100 parts by weight of the solid epoxy resin component in the photosensitive varnish based on the epoxy resin having an aliphatic skeleton, 0.2 part by weight of a yellow dye (Plast yellow 8070, manufactured by Arimoto Chemical Co., Ltd.) is added, The dye component was completely dissolved by stirring under heating at ° C. In this way, a varnish for forming an underclad layer comprising the following components was prepared.
(Under cladding layer varnish)
75 parts by weight of epoxy resin (manufactured by Daicel, EHPE-3150) 25 parts by weight of epoxy resin (manufactured by NOF Corporation, Marproof G-0150M) 5 parts by weight of photoacid generator (TINUVIH479, manufactured by Ciba Japan) Sun Apro, CPI-200K) 4 parts by weight Solvent (Wako Pure Chemical Industries, cyclohexanone) 70 parts by weight Yellow dye (Arimoto Chemical Co., Plast yellow 8070) 0.2 parts by weight

<Preparation of underclad layer>
The obtained varnish was coated on a SUS substrate (thickness 50 μm) using a spin coater (5000 rpm × 10 seconds) and dried at 150 ° C. for 3 minutes in a drying furnace. The obtained uncured underclad layer was exposed with a UV irradiator [B line, 1000 mJ (365 nm)] to produce an underclad layer (film thickness: 15 μm). Heating was not performed after the exposure, and the polymerization reaction of the epoxy group was advanced by the heat generated during the exposure.

<Production of alignment marks>
On the produced under clad layer, the following core varnish was applied using an applicator (applicator gap: about 100 μm) and dried in a drying furnace at 150 ° C. for 3 minutes. After drying, exposure (I line, 3000 mJ) was performed through a photomask, followed by heat treatment at 120 ° C. for 10 minutes. Next, it developed with γ-butyrolactone with a spray developing machine, washed with water to remove the unexposed portion, and dried to produce an alignment mark on the undercladding layer.
(Core varnish)
Epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., 157S70) 85 parts by weight epoxy resin (manufactured by NOF Corporation, Marproof G-0250SP) 10 parts by weight epoxy resin (manufactured by Japan Epoxy Resin Co., Epicoat 828) 5 parts by weight Photoacid generator 4 parts by weight of solvent (manufactured by Sun Apro, CPI-200K) 55 parts by weight of solvent (produced by Wako Pure Chemical Industries, Ltd., ethyl lactate)

[Example 2]
In the varnish for forming the underclad layer, the amount of yellow dye (Plast yellow 8070, manufactured by Arimoto Chemical Co., Ltd.) was changed to 0.4 parts by weight. Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

Example 3
In the undercladding layer forming varnish, 0.4 parts by weight of a red dye (Arimoto Chemical Co., Plast red8630) was used in place of the yellow dye (Arimoto Chemical Co., Plast yellow 8070). Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

Example 4
In the undercladding layer forming varnish, 1.2 parts by weight of a red dye (Arimoto Chemical Co., Plast red 8630) was used in place of the yellow dye (Arimoto Chemical Co., Plast yellow 8070). Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

Example 5
In the undercladding layer forming varnish, 0.3 part by weight of a green dye (Arimoto Chemical Co., Plast green8620) was used instead of the yellow dye (Arimoto Chemical Co., Plast yellow 8070). Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

Example 6
In the varnish for forming the underclad layer, 0.5 part by weight of a green dye (Plast green 8620, manufactured by Arimoto Chemical Co., Ltd.) was used instead of the yellow dye (Plast yellow 8070, manufactured by Arimoto Chemical Co., Ltd.). Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

[Comparative Example 1]
In the varnish for forming the underclad layer, the amount of yellow dye (Plast yellow 8070 manufactured by Arimoto Chemical Co., Ltd.) was changed to 0.1 parts by weight. Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

[Comparative Example 2]
In the undercladding layer forming varnish, 0.1 part by weight of a red dye (Arimoto Chemical Co., Plast red8630) was used instead of the yellow dye (Arimoto Chemical Co., Plast yellow 8070). Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

[Comparative Example 3]
In the undercladding layer-forming varnish, 0.1 part by weight of a green dye (Arimoto Chemical Co., Plast green 8620) was used instead of the yellow dye (Arimoto Chemical Co., Plast yellow 8070). Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

[Comparative Example 4]
In the varnish for forming the under cladding layer, the amount of yellow dye (Plast yellow 8070 manufactured by Arimoto Chemical Co., Ltd.) was changed to 0.14 parts by weight. Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

[Comparative Example 5]
No dye was used. Other than that was carried out similarly to Example 1, and produced the under clad layer and the alignment mark.

  The properties shown below were measured and evaluated for the example products and the comparative product manufactured as described above. The results are also shown in Table 1 below.

[Absorbance]
On the SUS base material, the under clad layer produced with a thickness of 15 μm was measured for the absorbance in a reflection mode using an integrating sphere with an ultraviolet-visible-near infrared spectrophotometer (manufactured by JASCO Corporation, V-670). ,evaluated. The target wavelengths are the blue light source (470 nm) for the yellow dye, the green light source (525 nm) for the red dye, the red light source (660 nm) for the green dye, and the absorbance at the light source wavelength used when each dye is used. evaluated.

〔Visibility〕
Using an image processing system (including a camera, manufacturing system, manufactured by Sharp Corporation, IV-S210X) from the under clad layer side, the light (wavelength light from the light source shown in Table 1 below) is irradiated. The visibility of the alignment mark was visually confirmed and evaluated. As a result, SUS reflection was suppressed and the alignment mark was clearly confirmed as usual. The evaluation was evaluated as ◯, and the alignment mark was difficult to visually recognize due to the SUS reflection.

[Propagation loss of optical waveguide]
About the obtained Example goods and comparative example goods, the propagation loss (dB / 5cm) in wavelength 850nm of length 5cm was measured using the cutback method.

  From the above results, the undercladding layer produced in the example had good visibility of the alignment mark by the alignment camera without significantly losing the propagation loss. On the other hand, all of the comparative example products were inferior in the visibility of the alignment mark by the alignment camera.

<Production of optical waveguide>
Next, an optical waveguide was produced. That is, as shown in FIG. 1C, a mold M made of a translucent resin (silicone resin) cured body 20 and a quartz glass plate G for forming an overcladding layer is prepared. An optical waveguide (see FIG. 5) was prepared based on the manufacturing method of the optical waveguide in the above-described embodiment using the under-cladding layer varnish (also used for over-cladding layer formation) and the core varnish prepared in the above. At that time, the alignment mark (using light having a wavelength from each light source shown in Table 1) was visually recognized, so that the optical waveguide could be manufactured with good workability.

  The optical waveguide manufacturing method of the present invention can be used for manufacturing optical waveguides used in optical communication, optical information processing, detecting means (position sensor) for a touch position of a finger or the like on a touch panel, and the like.

DESCRIPTION OF SYMBOLS 1 Under clad layer 1a, 22 Alignment mark 2 Core 3 Over clad layer M Mold

Claims (4)

  A step of forming an underclad layer on the surface of the metal substrate, a step of patterning a core on the surface of the underclad layer, a step of forming an alignment mark at a predetermined position of the underclad layer, and the shape of the overclad layer A step of preparing a mold in which a recess having a mold surface corresponding to is formed and an alignment mark corresponding to the alignment mark formed in the undercladding layer is formed at a predetermined position; and When the metal substrate and the molding die are aligned with the metal substrate on which the under cladding layer is formed and the metal substrate and the molding die are aligned based on the corresponding pair of alignment marks, light with a wavelength of 400 to 700 nm is irradiated from the molding die side. The alignment process using the irradiation light and the over clad layer with the core covered The under-cladding layer contains a dye that absorbs light having a wavelength of 400 to 700 nm, and has an absorbance of 0.24 or more with respect to light having a wavelength of 400 to 700 nm used for the alignment. A process for producing an optical waveguide, characterized by comprising:   2. The method of manufacturing an optical waveguide according to claim 1, wherein the alignment is performed using an alignment camera.   The mold is made of a translucent resin, and the step of aligning the metal substrate and the mold with reference to the alignment mark is performed from the back side of the translucent resin mold. Through the alignment camera, the step of confirming and aligning both alignment marks and forming the overcladding layer is carried out in the recess of the translucent resin molding die. 3. The method according to claim 1, wherein the photosensitive resin is filled in the photosensitive resin, and the core is embedded in the photosensitive resin, and the photosensitive resin is exposed and cured through the mold to form an overcladding layer. Of optical waveguide.   The method for producing an optical waveguide according to any one of claims 1 to 3, wherein a mold surface portion of the concave portion of the mold corresponding to an over clad layer portion covering the tip portion of the core is formed on a lens curved surface. .

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