JP2013231860A - Manufacturing method of lens-equipped optical waveguide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a lens-equipped optical waveguide having optical path conversion mirrors with excellent light transmission efficiency.SOLUTION: A manufacturing method of a lens-equipped optical waveguide includes: a first step of forming lenses on one surface of a base plate; a second step of forming a lower clad layer on the other surface of the base plate; a third step of forming an optical signal transmitting core pattern on the lower clad layer; a fourth step of forming an upper clad layer on the optical signal transmitting core pattern; and a fifth step of forming optical path conversion mirrors on the optical signal transmitting core pattern. The fifth step is performed after the completion of the first step.

Description

  The present invention relates to a method of manufacturing an optical waveguide with a lens, and particularly relates to a method of manufacturing an optical waveguide with a lens including an optical path conversion mirror having good light transmission efficiency.

  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 server devices is underway. In particular, as an optical transmission path for using light for short-distance signal transmission between boards in a router or a server device, optical fibers that have a higher degree of freedom in wiring and can be densified than optical fibers. It is desirable to use a waveguide. Among them, an optical waveguide using a polymer material excellent in processability and economy is promising.

As such an optical waveguide, for example, as described in Patent Document 1, first, after the lower cladding layer is cured and formed, a core pattern is formed on the lower cladding layer, and the upper cladding layer is laminated, An optical waveguide in which an optical waveguide is formed and then an optical path conversion mirror portion is formed by cutting has been proposed.
When connecting an optical signal propagating through the core pattern by connecting an independent external optical member such as a light emitting / receiving element, an optical fiber connector, or another optical waveguide to such an optical waveguide, the core pattern and the external optical member It is necessary to suppress transmission loss.

JP 2006-011210 A

However, in the optical waveguide described in Patent Document 1, light that has been optically path-converted by the optical path conversion mirror and emitted to the outside of the optical waveguide is diffused until reaching the light-receiving portion of the external optical member, resulting in light loss. There was a problem of getting bigger.
Therefore, the present inventors have studied a method for emitting light that has undergone optical path conversion in an optical path conversion mirror to the outside through a condenser lens for the purpose of reducing optical loss. It has been found that when a film is laminated and a condensing lens is formed by a photolithography method, the optical waveguide is deformed in a thin mirror forming portion.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing an optical waveguide with a lens including an optical path conversion mirror with good light transmission efficiency.

The present inventors have found that the above problem can be solved by performing a step of forming an optical path conversion mirror on the optical signal transmission core pattern after completing the step of forming a lens, and the present invention has been completed. It is a thing.
That is, the present invention provides the following inventions.
1. A first step of forming a lens on one side of the substrate; a second step of forming a lower cladding layer on the other side of the substrate; and a first step of forming a core pattern for transmitting an optical signal on the lower cladding layer. 3 steps, a fourth step of forming an upper clad layer on the optical signal transmission core pattern, and a fifth step of forming an optical path conversion mirror on the optical signal transmission core pattern, The manufacturing method of the optical waveguide with a lens by which this 5th process is performed after 1 process is completed.
2. 2. The method for manufacturing an optical waveguide with a lens according to 1 above, wherein the first step is performed simultaneously with any one of the second step to the fourth step.
3. 3. The method for manufacturing an optical waveguide with a lens according to 2, wherein the first step is performed simultaneously with the second step or the third step.
4). 4. The method for manufacturing an optical waveguide with a lens according to 3 above, wherein the first step is performed simultaneously with the second step.
5. 5. The method for manufacturing an optical waveguide with a lens according to any one of 1 to 4, wherein the first step is performed by photolithography.
6). 6. The method of manufacturing an optical waveguide with a lens according to any one of 1 to 5, wherein the fifth step is performed by cutting a core pattern for transmitting an optical signal.
7). The manufacturing method of the optical waveguide with a lens in any one of said 1-6 whose said board | substrate is a polyimide board | substrate.
8). Furthermore, the optical waveguide with a lens according to any one of the above 1 to 7, further comprising a sixth step in which a resist or a dummy lens having a thickness equal to or greater than a lens thickness is provided on one surface of the substrate in parallel with the lens. Manufacturing method.

  The optical waveguide with a lens including the optical path conversion mirror obtained by the manufacturing method of the present invention is excellent in light transmission efficiency with the external optical member.

(A) The perspective view of the optical waveguide obtained by the manufacturing method of this invention, (b) The top view of the optical waveguide of Fig.1 (a), (c) AA 'line cross section of the optical waveguide of Fig.1 (b) FIG. It is a figure which shows the manufacturing method of the optical waveguide of FIG.1 (b) in a B-B 'line sectional drawing.

  The optical waveguide with a lens obtained by the manufacturing method of the present invention has a lens 6 on one surface side of the substrate 1, and a lower cladding layer 2, an optical signal transmission core pattern 3 on the other surface side of the substrate 1, and An optical waveguide in which an upper clad layer 4 is sequentially laminated and includes an optical path conversion mirror 5 on the optical signal transmission core pattern 3, and the optical path conversion mirror 5 propagates through the optical signal transmission core pattern 3. The lower clad layer 2 side or upper clad is positioned on the optical path of the light and is inclined with respect to the optical path, and is positioned on the optical path of the light that has been converted by the optical path conversion mirror 5. A lens 6 is provided on the layer 4 side.

  The method for manufacturing an optical waveguide with a lens according to the present invention includes a first step of forming a lens on one surface side of a substrate, a second step of forming a lower cladding layer on the other surface side of the substrate, and the lower cladding layer. A third step of forming an optical signal transmission core pattern thereon; a fourth step of forming an upper cladding layer on the optical signal transmission core pattern; and forming an optical path conversion mirror on the optical signal transmission core pattern The fifth step is performed after the first step is completed. Hereinafter, each step will be described.

(First step)
The first step is a step of forming the lens 6 on one surface side of the substrate 1 as shown in FIGS.
Although the lens 6 manufactured separately as described above may be bonded via an adhesive or the like, the lens 6 is preferably formed by a photolithography method. Hereinafter, as an example of a lens forming method, an example in which a lens is formed with a negative photoresist will be described, but the lens may be formed with a positive photoresist.

In the step shown in FIG. 2A, a lens forming resin layer 6 a made of a photosensitive resin composition is laminated on one surface of the substrate 1. The lens-forming resin layer 6a is formed by, for example, applying a coating solution obtained by uniformly dissolving or decomposing each component of the photosensitive resin composition in a solvent to the other surface of the substrate 1 to form a coating film. It is formed by removing the solvent from the coating film by drying.
However, the lens-forming resin layer 6 a may be provided by sticking a lens photosensitive element formed by laminating a photosensitive layer made of a photosensitive resin composition on a support film to the substrate 1.

  Next, in the step shown in FIG. 2B, a lens photomask having a predetermined pattern is put on the surface side on which the lens forming resin layer 6a is formed, and a specific actinic ray is applied through the lens photomask. Irradiate the lens-forming resin layer 6a to cure the lens formation planned portion, and then remove an uncured portion other than the lens formation planned portion by development using a developer, and on one surface of the substrate 1 A plurality of lens forming resists 6b are formed.

  As the active light for curing the lens-forming resin layer 6 a, ultraviolet rays are usually used. However, when a polyimide substrate is used as the substrate 1, the active rays (ultraviolet rays) do not pass through the substrate 1. Therefore, actinic rays irradiated on each surface of the substrate do not pass through the substrate and are not irradiated on the opposite surface, so that appropriate photolithography processing can be performed.

  The lens forming resist 6b is developed by a known method such as spraying, showering, rocking dipping, brushing or scraping using a known developing solution such as an alkaline aqueous solution, aqueous developer, or organic solvent. And a method of removing the unexposed area is preferable. Among them, it is preferable to use an alkaline aqueous solution from the viewpoint of environment and safety.

  Examples of the base of the alkaline aqueous solution include alkali hydroxide (lithium, sodium or potassium hydroxide, etc.), alkali carbonate (lithium, sodium or potassium carbonate or bicarbonate, etc.), alkali metal phosphate (potassium phosphate, etc.) And sodium phosphate, alkali metal pyrophosphate (sodium pyrophosphate, potassium pyrophosphate, etc.), tetramethylammonium hydroxide, monoethanolamine, and triethanolamine.

  After the development, the formed lens forming resist 6b is further heated and melted so that the surface opposite to the surface in contact with the substrate 1 is a convex surface having a desired curvature to form the lens 6. (See FIG. 2 (c)).

The lens 6 is formed before the optical path conversion mirror 5 described later is formed. If the lens 6 is formed by the photolithography method after the optical path conversion mirror 5 is formed, problems such as distortion occur in the optical path conversion mirror 5 forming portion when the lens forming resin layer 6a is laminated.
In addition, the exposure development in the first step can be performed simultaneously with the exposure development in the second to fourth steps, which will be described later. Further, from the viewpoint of forming the lens 6 with high accuracy, it is preferable to form the lens 6 at a stage where the influence of thermal shrinkage is small. Therefore, the exposure development in the first step is the same as the exposure development in the second step or the third step. It is more preferable to carry out simultaneously, and it is especially preferable to carry out simultaneously with the exposure development in the second step.

(Second step)
The second step is a step of forming the lower clad layer 2 on the substrate 1, as shown in FIGS. 2A to 2B, and laminating the resin layer 2a for forming the clad layer, and exposing and developing. Can be done.
The method for laminating the clad layer forming resin layer 2a on the substrate 1 is not particularly limited. However, when the clad layer forming resin is varnished, it may be applied to the substrate 1 by a conventional method. When the resin is in the form of a film, various methods such as a roll laminator, a vacuum pressure laminator, a press, and a vacuum press may be used.

(Third step)
In the third step, as shown in FIGS. 2D to 2E, a core forming resin layer 3a is laminated on the lower cladding layer 2, and the optical signal transmitting core pattern 3 is formed by exposure and development. It is.
The method of laminating the core forming resin layer 3a on the substrate 1 can be performed in the same manner as the laminating method of the clad layer forming resin layer 2a.

(4th process)
The fourth step is a step of forming the upper clad layer 4 on the optical signal transmission core pattern 3 as shown in FIG.
The method of laminating the clad layer forming resin layer on the optical signal transmitting core pattern 3 can be performed in the same manner as in the second step.

(5th process)
The fifth step is a step of forming the optical path conversion mirror 5 on the optical signal transmission core pattern 3.
The method for forming the optical path conversion mirror 5 is not particularly limited, and a known method can be applied. For example, the optical signal transmission core pattern 3 can be formed by cutting the optical signal transmission core pattern 3 from the surface where the optical signal transmission core pattern 3 is formed using a dicing saw or the like. The angle of the optical path conversion mirror 5 to be formed is preferably about 45 ° (for example, 40 to 50 °).
Moreover, it is good also as a mirror provided with the reflective metal layer by vapor-depositing metals, such as gold | metal | money, using the vapor deposition apparatus for the optical path conversion mirror 5. FIG.

  The method for manufacturing an optical waveguide with a lens according to the present invention further includes a step of laminating a lid material layer on the surface side cut in the fifth step when an optical waveguide having a lid material layer is produced.

Hereafter, each component in the manufacturing method of the optical waveguide with a lens of this invention is demonstrated in detail.
[substrate]
There is no restriction | limiting in particular as the material of the board | substrate 1 which can be used for the manufacturing method of the optical waveguide with a lens of this invention, For example, a glass epoxy resin substrate, a ceramic substrate, a glass substrate, a silicon substrate, a plastic substrate, a metal substrate, with a resin layer Examples include a substrate, a substrate with a metal layer, a plastic film, a plastic film with a resin layer, a plastic film with a metal layer, and an electric wiring board. In addition, the substrate 1 has flexibility and toughness, and can transmit light on a short wavelength side such as an actinic ray used in photolithography while transmitting light on a long wavelength side such as an optical signal. It is preferable to use a polyamide substrate, a polyamideimide, or a polyimide substrate, and more preferably a polyimide substrate.
When the substrate 1 has the lens 6 on the substrate 1 side, the substrate 1 is preferably a transparent substrate that transmits light that has undergone optical path conversion by the optical path conversion mirror.
The thickness of the substrate 1 is preferably 5 μm to 1 mm, and more preferably 10 μm to 100 μm. A thickness of the substrate 1 of 5 μm or more is preferable from the viewpoint of the rigidity of the substrate 1, and a thickness of 1 mm or less is preferable because the optical signal reflected by the optical path conversion mirror 5 enters the lens 6 before spreading.

[Lower cladding layer and upper cladding layer]
The lower clad layer 2 and the upper clad layer 4 in the method for producing an optical waveguide with a lens can be formed, for example, by laminating a resin layer for forming a clad layer and exposing and developing it. The clad layer forming resin may be a composition containing a plurality of components.
The clad layer forming resin used in the present invention is not particularly limited as long as it is a resin that has a refractive index lower than that of the optical signal transmission core pattern 3 and is cured by light or heat, and a thermosetting resin or a photosensitive resin is preferable. Can be used for The resin for forming the clad layer may be the same or different in the components contained in the resin in the lower clad layer 2 and the upper clad layer 4, and may differ even if the refractive index of the resin is the same. Also good.

The method for laminating the clad layer forming resin layer is not particularly limited. For example, the clad layer forming resin film may be laminated by dissolving the clad layer forming resin in a solvent. May be laminated.
In the case of application, the method is not limited, and the clad layer forming resin may be applied by a conventional method.
The clad layer forming resin film used for laminating can be easily manufactured by, for example, dissolving the clad layer forming resin in a solvent, applying the resin on the carrier film, and removing the solvent.

  The thickness of the lower cladding layer 2 and the upper cladding 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.

(Core pattern for optical signal transmission)
The optical signal transmission core pattern 3 can be formed, for example, by laminating a resin layer for forming a core layer, and exposing and developing. The core layer forming resin may be a composition containing a plurality of components.
The core layer forming resin preferably has a higher refractive index than the lower cladding layer 2 and the upper cladding layer 4 and can be patterned by actinic rays. The method for forming the core layer forming resin layer before patterning is not limited. For example, the core layer forming resin may be laminated by dissolving the resin for forming the core layer in a solvent. A resin film may be laminated.

  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 layer 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 the formation of the optical waveguide, and when it is 100 μm or less, There is an advantage that the coupling efficiency is improved in coupling with the light emitting / receiving element or the optical fiber after the optical waveguide is formed. From the above viewpoint, the thickness of the film is preferably in the range of 30 to 90 μm, and the film thickness may be appropriately adjusted in order to obtain the thickness.

  As the core layer forming resin, it is preferable to use a resin that is transparent to an optical signal to be used and can form a pattern with actinic rays.

[Optical path conversion mirror]
The optical path conversion mirror 5 transmits an optical signal propagated through the optical signal transmission core pattern 3 extending in a direction substantially parallel to the plane of the optical waveguide from the substrate 1 side (from the lower clad layer 2 side when the substrate 1 is not provided). ) Or a structure that changes the optical path from the upper clad layer 4 side in a direction substantially perpendicular to the plane of the optical waveguide, and there is no particular limitation. The optical signal transmission core pattern 3 is provided with a notch of about 45 °. An air reflection mirror may be used, or a metal reflection mirror in which a reflective metal layer is formed in the cutout portion.
As shown in FIG. 1, the optical path conversion mirror 5 is formed by cutting the optical signal transmission core pattern 3 from the substrate 1 side using a dicing saw or the like, or from the upper clad layer 4 side. It can be formed by cutting the optical signal transmission core pattern 3 using a dicing saw or the like, and is preferably about 45 ° with respect to the traveling direction of the optical signal transmission core pattern 3.

<Lens>
The lens 6 is a convex lens having a convex surface on the substrate 1 side (the lower clad layer 2 side when no substrate 1 is provided) or the upper clad layer 4 side, and an optical signal transmission core pattern. 3 is preferably a condensing lens for receiving the light signal propagated through the light receiving portion of the external optical member. The manufacturing method of the lens 6 is not particularly limited, and a separately manufactured one may be bonded via an adhesive or the like, but is preferably formed of a photosensitive resin composition so that it can be formed by photolithography. It is more preferable that the lens is formed of a negative photoresist in terms of improving the transparency of the lens.

A plurality of lenses 6 can be provided as necessary.
In addition, the distance along the height direction (perpendicular to the optical waveguide plane) from the optical path conversion mirror 5 to the lens 6 is preferably about 20 to 500% of the core diameter, and is 20 to 100%. Further, it is preferable because the optical loss in the optical path between the lens 6 and the optical path conversion mirror 5 can be minimized. The distance along the height direction from the optical path conversion mirror 5 to the lens 6 can be strictly specified as the distance at the mirror center point.
Furthermore, it is preferable that the shape and size of the lens 6 include the projection of the optical path conversion mirror 5 onto the optical waveguide plane in order to efficiently receive the light from the optical path conversion mirror 5. Specifically, the diameter along the direction parallel to the optical waveguide plane is preferably 100 to 700%, more preferably 100 to 250% of the core diameter. When the shape of the lens 6 is an ellipse, it is preferable that at least one of the major axis and the minor axis satisfies the above range, and it is more preferable that both satisfy the above range.

(Photosensitive resin composition for lens)
The photosensitive resin composition for forming the lens 6 includes, for example, (a) a binder polymer, (b) a photopolymerizable unsaturated compound having an ethylenically unsaturated group, and (c) free radicals by active light. And a photopolymerization initiator to be produced. By using such a photosensitive resin composition, the resolution and adhesion of the lens-forming resin layer 6a can be improved and the light transmittance of the lens can be more reliably ensured, so that the optical performance and productivity of the lens can be improved. Furthermore, both can be achieved at a high level.

  (A) As a binder polymer, a vinyl copolymer (a1) is mentioned, for example, Specifically, what was obtained by polymerizing the following vinyl monomer is mentioned. For example, (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, ( N-butyl (meth) acrylate, iso-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, ( Heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, tetradecyl (meth) acrylate, Hexadecyl (meth) acrylate, octadecyl (meth) acrylate, Eiko (meth) acrylate , Docosyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, (meth) acrylic acid Methoxyethyl, methoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 2-hydroxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, Diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-fluoroethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, styrene, α-methyls Tylene, cyclohexylmaleimide, dicyclopentanyl (meth) acrylate, vinyl toluene, vinyl chloride, vinyl acetate, N-vinyl pyrrolidone, butadiene, isoprene, chloroprene, (meth) acrylamide, methacrylamide, (meth) acrylonitrile, etc. It is done. These may be polymerized singly or in combination of two or more.

  Furthermore, in the photosensitive resin composition for lenses of the present embodiment, (a) as a binder polymer, for example, a vinyl copolymer having a functional group such as a carboxyl group, a hydroxyl group, an amino group, an isocyanate group, an oxirane ring, and an acid anhydride. One functional group such as an oxirane ring, an isocyanate group, a hydroxyl group, and a carboxyl group that reacts with and binds to the functional group of the vinyl copolymer, and at least one ethylenically unsaturated group. It is also possible to use a radically polymerizable copolymer (a2) having an ethylenically unsaturated group in the side chain obtained by the addition reaction of the compound having it.

  Examples of the vinyl monomer used in the production of the vinyl copolymer having a functional group such as a carboxyl group, a hydroxyl group, an amino group, an oxirane ring, and an acid anhydride include (meth) acrylic acid, maleic acid, and fumaric acid. , Itaconic acid, cinnamic acid, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, ethyl methacrylate, glycidyl (meth) acrylate, maleic anhydride and the like. These may be polymerized singly or in combination of two or more. Moreover, the said vinyl monomers other than the vinyl monomer which has functional groups, such as a carboxyl group, a hydroxyl group, an amino group, an oxirane ring, and an acid anhydride, can be copolymerized as needed.

  Furthermore, (a) the binder polymer can be obtained, for example, by copolymerizing a sulfur-containing compound represented by the following general formula (I) with an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride. A sulfur-containing copolymer (a3) may be used.

In the formula (I), R ¹ represents a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent or an aryl group which may have a substituent, R ² represents a hydrogen atom or a methyl group, A represents a divalent organic group, X ¹ and X ² each independently represent a sulfur atom or an oxygen atom, and at least one of X ¹ and X ² is a sulfur atom It is.
The sulfur-containing compound represented by the general formula (I) is a (meth) acrylic acid ester compound, and is characterized by containing a sulfur atom.

When R ¹ is an alkyl group which may have a substituent, examples of the substituent include an alkoxy group, an aralkyloxy group, an aryloxy group, an aryl group which may have an alkyl group. Examples thereof include an oxyalkyloxy group, an alkylthio group, an aralkylthio group, an arylthio group, and an arylthioalkylthio group. In addition, when R ¹ is an aralkyl group which may have a substituent or an aromatic residue which may have a substituent, examples of the substituent include an aralkyl group or an aromatic residue. The substituents that may be substituted are alkyl groups, alkoxy groups, aryl groups, aralkyloxy groups, aryloxy groups, aryloxyalkyloxy groups, alkylthio groups, aralkylthio groups, arylthio groups, arylthioalkylthio groups, and halogen atoms. Can be mentioned.

Examples of R ¹ include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, and an n-hexyl group. Linear, branched or cyclic alkyl groups such as heptyl group, octyl group, cyclohexyl group, cyclohexylmethyl group, benzyl group, 4-methylbenzyl group, 4-chlorobenzyl group, 4-bromobenzyl group, β-phenyl Substituted or unsubstituted aralkyl groups such as ethyl group, phenyl group, 4-methylphenyl group, 3-methylphenyl group, 2-methylphenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group 4-phenylphenyl group, 4-phenoxyphenyl group, 3-phenoxyphenyl group, 2-phenoxyphenyl group, 4-methylthiophenyl group, 3-methylthiophenyl group, 2-methylthiophenyl group, 4-chlorophenyl group, 3-chlorophenyl group, 2-chlorophenyl group, 4-bromophenyl group, 3-bromophenyl group, 2-bromophenyl group , Α-naphthyl group, β-naphthyl group and the like substituted or unsubstituted aryl groups. From the viewpoint of increasing transparency and refractive index, R ¹ is preferably a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group.
Specifically, A is preferably an alkylene group having 1 to 10 carbon atoms which may contain an oxygen atom or a sulfur atom, and more preferably an alkylene group having 2 to 5 carbon atoms. Moreover, it is preferable that X < ¹ > and X < ² > are sulfur atoms from a viewpoint of making a refractive index higher.

Examples of the sulfur-containing compound represented by the general formula (I) include 1-thiomethyl-2- (meth) acryloylthiomethane, 1-thiomethyl-2- (meth) acryloylthioethane, 1-thiomethyl-2- ( (Meth) acryloylthio-n-propane, 1-thiomethyl-2- (meth) acryloylthio-n-butane, 1-thiomethyl-2- (meth) acryloylthio-n-pentane, 1-thiomethyl-2- (meth) Acryloylthio-n-hexane, 1-thioethyl-2- (meth) acryloylthio-n-heptane, 1-thioethyl-2- (meth) acryloylthio-n-octane, 1-thioethyl-2- (meth) acryloylthio Methane, 1-thioethyl-2- (meth) acryloylthioethane, 1-thioethyl-2- (meth) acryloylthio n-propane, 1-thioethyl-2- (meth) acryloylthio-n-butane, 1-thioethyl-2- (meth) acryloylthio-n-pentane, 1-thioethyl-2- (meth) acryloylthio-n- Hexane, 1-thioethyl-2- (meth) acryloylthio-n-heptane, 1-thioethyl-2- (meth) acryloylthio-n-octane, 1-thio-n-propyl-2- (meth) acryloylthiomethane 1-thio-n-propyl-2- (meth) acryloylthioethane, 1-thio-n-propyl-2- (meth) acryloylthio-n-propane, 1-thio-n-propyl-2- (meth) ) Acryloylthio-n-butane, 1-thio-n-propyl-2- (meth) acryloylthio-n-pentane, 1-thio-n-propyl-2- ( T) acryloylthio-n-hexane, 1-thio-n-propyl-2- (meth) acryloylthio-n-heptane, 1-thio-n-propyl-2- (meth) acryloylthio-n-octane, 1 -Thio-n-butyl-2- (meth) acryloylthiomethane, 1-thio-n-butyl-2- (meth) acryloylthioethane, 1-thio-n-butyl-2- (meth) acryloylthio-n -Propane, 1-thio-n-butyl-2- (meth) acryloylthio-n-butane, 1-thio-n-butyl-2- (meth) acryloylthio-n-pentane, 1-thio-n-butyl 2- (meth) acryloylthio-n-hexane, 1-thio-n-butyl-2- (meth) acryloylthio-n-heptane, 1-thio-n-butyl-2- (meth) acryloylthio -N-octane, 1-thiobenzyl-2- (meth) acryloylthiomethane, 1-thiobenzyl-2- (meth) acryloylthioethane, 1-thiobenzyl-2- (meth) acryloylthio-n-propane, 1-thiobenzyl 2- (meth) acryloylthioisopropane, 1-thiobenzyl-2- (meth) acryloylthio-n-butane, 1-thiobenzyl-2- (meth) acryloylthioisobutane, 1-thiobenzyl-2- (meth) acryloyl Thio-n-pentane, 1-thiobenzyl-2- (meth) acryloylthioisopentane, 1-thiobenzyl-2- (meth) acryloylthio-n-hexane, 1-thiobenzyl-2- (meth) acryloylthio-n-heptane 1-thiobenzyl-2- (meth) acryloylthio-n-oct 1-thio- (4′-methylbenzyl) -2- (meth) acryloylthiomethane, 1-thio- (4′-methylbenzyl) -2- (meth) acryloylthioethane, 1-thio- (4 '-Methylbenzyl) -2- (meth) acryloylthio-n-propane, 1-thio- (4'-methylbenzyl) -2- (meth) acryloylthioisopropane, 1-thio- (4'-methylbenzyl) ) -2- (Meth) acryloylthio-n-butane, 1-thio- (4′-methylbenzyl) -2- (meth) acryloylthioisobutane, 1-thio- (4′-methylbenzyl) -2- ( (Meth) acryloylthio-n-pentane, 1-thio- (4′-methylbenzyl) -2- (meth) acryloylthioisopentane, 1-thio- (4′-methylbenzyl) -2- (meth) acryloyl Thio-n-hexane, 1-thio- (4′-methylbenzyl) -2- (meth) acryloylthio-n-heptane, 1-thio- (4′-methylbenzyl) -2- (meth) acryloylthio- n-octane, 1-thio- (4′-methylthiobenzyl) -2- (meth) acryloylthiomethane, 1-thio- (2′-methylthiobenzyl) -2- (meth) acryloylthioethane, 1-thio- (3'-methylthiobenzyl) -2- (meth) acryloylthioethane, 1-thio- (4'-methylthiobenzyl) -2- (meth) acryloylthioethane, 1-thio- (4'-methylthiobenzyl)- 2- (meth) acryloylthio-n-propane, 1-thio- (4′-methylthiobenzyl) -2- (meth) acryloylthioisopropane, 1-thio- (4′-methylthio) Benzyl) -2- (meth) acryloylthio-n-butane, 1-thio- (4′-methylthiobenzyl) -2- (meth) acryloylthioisobutane, 1-thio- (4′-methylthiobenzyl) -2- (Meth) acryloylthio-n-pentane, 1-thio- (4′-methylthiobenzyl) -2- (meth) acryloylthioisopentane, 1-thio- (4′-methylthiobenzyl) -2- (meth) acryloylthio -N-hexane, 1-thio- (4'-methylthiobenzyl) -2- (meth) acryloylthio-n-heptane, 1-thio- (4'-methylthiobenzyl) -2- (meth) acryloylthio-n -Octane, 1-thio- (4'-methyloxybenzyl) -2- (meth) acryloylthiomethane, 1-thio- (4'-methyloxybenzyl) -2- (Meth) acryloylthioethane, 1-thio- (4′-methyloxybenzyl) -2- (meth) acryloylthio-n-propane, 1-thio- (4′-methyloxybenzyl) -2- (meth) acryloyl Thioisopropane, 1-thio- (4′-methyloxybenzyl) -2- (meth) acryloylthio-n-butane, 1-thio- (4′-methyloxybenzyl) -2- (meth) acryloylthioisobutane 1-thio- (4′-methyloxybenzyl) -2- (meth) acryloylthio-n-pentane, 1-thio- (4′-methyloxybenzyl) -2- (meth) acryloylthioisopentane, Thio- (4′-methyloxybenzyl) -2- (meth) acryloylthio-n-hexane, 1-thio- (4′-methyloxybenzyl) -2- (meth) Acryloylthio-n-heptane, 1-thio- (4′-methyloxybenzyl) -2- (meth) acryloylthio-n-octane, 1-thio- (4′-chlorobenzyl) -2- (meth) acryloylthio Ethane, 1-thio- (4′-bromobenzyl) -2- (meth) acryloylthioethane, 1-thio- (4′-phenylethylbenzyl) -2- (meth) acryloylthioethane, 1-thiophenyl-2 -(Meth) acryloylthiomethane, 1-thiophenyl-2- (meth) acryloylthioethane, 1-thiophenyl-2- (meth) acryloylthio-n-propane, 1-thiophenyl-2- (meth) acryloylthioisopropane 1-thiophenyl-2- (meth) acryloylthio-n-butane, 1-thiophenyl-2- (meth) acryloyl Thioisobutane, 1-thiophenyl-2- (meth) acryloylthio-n-pentane, 1-thiophenyl-2- (meth) acryloylthioisopentane, 1-thiophenyl-2- (meth) acryloylthio-n-hexane, 1- Thiophenyl-2- (meth) acryloylthio-n-heptane, 1-thiophenyl-2- (meth) acryloylthio-n-octane, 1-thio- (4′-methylphenyl) -2- (meth) acryloylthiomethane 1-thio- (2′-methylphenyl) -2- (meth) acryloylthioethane, 1-thio- (3′-methylphenyl) -2- (meth) acryloylthioethane, 1-thio- (4 ′ -Methylphenyl) -2- (meth) acryloylthioethane, 1-thio- (4'-methylphenyl) -2- (meth) acryloyl Thio-n-propane, 1-thio- (4′-methylphenyl) -2- (meth) acryloylthioisopropane, 1-thio- (4′-methylphenyl) -2- (meth) acryloylthio-n— Butane, 1-thio- (4′-methylphenyl) -2- (meth) acryloylthioisobutane, 1-thio- (4′-methylphenyl) -2- (meth) acryloylthio-n-pentane, 1-thio -(4'-methylphenyl) -2- (meth) acryloylthioisopentane, 1-thio- (4'-methylphenyl) -2- (meth) acryloylthio-n-hexane, 1-thio- (4'- Methylphenyl) -2- (meth) acryloylthio-n-heptane, 1-thio- (4′-methylphenyl) -2- (meth) acryloylthio-n-octane, 1-thio- (4′-methylthio) Enyl) -2- (meth) acryloylthiomethane, 1-thio- (2′-methylthiophenyl) -2- (meth) acryloylthioethane, 1-thio- (3′-methylthiophenyl) -2- (meth) Acryloylthioethane, 1-thio- (4′-methylthiophenyl) -2- (meth) acryloylthioethane, 1-thio- (4′-methylthiophenyl) -2- (meth) acryloylthio-n-propane, 1 -Thio- (4'-methylthiophenyl) -2- (meth) acryloylthioisopropane, 1-thio- (4'-methylthiophenyl) -2- (meth) acryloylthio-n-butane, 1-thio- ( 4'-methylthiophenyl) -2- (meth) acryloylthioisobutane, 1-thio- (4'-methylthiophenyl) -2- (meth) acryloylthio-n- Pentane, 1-thio- (4′-methylthiophenyl) -2- (meth) acryloylthioisopentane, 1-thio- (4′-methylthiophenyl) -2- (meth) acryloylthio-n-hexane, 1-thio -(4'-methylthiophenyl) -2- (meth) acryloylthio-n-heptane, 1-thio- (4'-methylthiophenyl) -2- (meth) acryloylthio-n-octane, 1-thio- ( 4′-methyloxyphenyl) -2- (meth) acryloylthiomethane, 1-thio- (4′-methyloxyphenyl) -2- (meth) acryloylthioethane, 1-thio- (4′-methyloxyphenyl) ) -2- (Meth) acryloylthio-n-propane, 1-thio- (4′-methyloxyphenyl) -2- (meth) acryloylthioisopropane, 1-thio -(4'-methyloxyphenyl) -2- (meth) acryloylthio-n-butane, 1-thio- (4'-methyloxyphenyl) -2- (meth) acryloylthioisobutane, 1-thio- (4 '-Methyloxyphenyl) -2- (meth) acryloylthio-n-pentane, 1-thio- (4'-methyloxyphenyl) -2- (meth) acryloylthioisopentane, 1-thio- (4'-methyl) Oxyphenyl) -2- (meth) acryloylthio-n-hexane, 1-thio- (4′-methyloxyphenyl) -2- (meth) acryloylthio-n-heptane, 1-thio- (4′-methyl) Oxyphenyl) -2- (meth) acryloylthio-n-octane, 1-thio- (4′-phenylphenyl) -2- (meth) acryloylthioethane, 1-thio- (4′- Phenyloxyphenyl) -2- (meth) acryloylthioethane, 1-thio- (4′-chlorophenyl) -2- (meth) acryloylthioethane, 1-thio- (4′-bromophenyl) -2- (meth) ) Acryloylthioethane, 1-thionaphthyl-2- (meth) acryloylthioethane, 1-thiomethyl-2- (meth) acryloyloxyethane, 1-thioethyl-2- (meth) acryloyloxyethane, 1-thio-n- Propyl-2- (meth) acryloyloxyethane, 1-thio-n-butyl-2- (meth) acryloyloxyethane, 1-thiobenzyl-2- (meth) acryloyloxyethane, 1-thio- (4′-methyl) Benzyl) -2- (meth) acryloyloxyethane, 1-thio- (2′-methylthiobenzyl) -2- (meth) Acryloyloxyethane, 1-thio- (3′-methylthiobenzyl) -2- (meth) acryloyloxyethane, 1-thio- (4′-methylthiobenzyl) -2- (meth) acryloyloxyethane, 1-thio- (4'-methyloxyben


Diyl) -2- (meth) acryloyloxyethane, 1-thio- (4′-chlorobenzyl) -2- (meth) acryloyloxyethane, 1-thio- (4′-bromobenzyl) -2- (meth) Acryloyloxyethane, 1-thio- (4′-phenylethylbenzyl) -2- (meth) acryloyloxyethane, 1-thiophenyl-2- (meth) acryloyloxyethane, 1-thio- (2′-methylphenyl) 2- (meth) acryloyloxyethane, 1-thio- (3′-methylphenyl) -2- (meth) acryloyloxyethane, 1-thio- (4′-methylphenyl) -2- (meth) acryloylthio Ethane, 1-thio- (2′-methylthiophenyl) -2- (meth) acryloyloxyethane, 1-thio- (3′-methylthiophenyl) -2- ( T) acryloyloxyethane, 1-thio- (4'-methylthiophenyl) -2- (meth) acryloyloxyethane, 1-thio- (4'-methyloxyphenyl) -2- (meth) acryloyloxyethane, 1 -Thio- (4'-phenylphenyl) -2- (meth) acryloyloxyethane, 1-thio- (4'-phenyloxyphenyl) -2- (meth) acryloyloxyethane, 1-thio- (4'- Chlorophenyl) -2- (meth) acryloyloxyethane, 1-thio- (4′-bromophenyl) -2- (meth) acryloyloxyethane, 1-thionaphthyl-2- (meth) acryloyloxyethane. These can be used alone or in combination of two or more.

  There is no restriction | limiting in particular as unsaturated carboxylic acid and / or unsaturated carboxylic anhydride which are copolymerized with the sulfur containing compound represented by general formula (I), For example, (meth) acrylic acid, crotonic acid, 2 -Monocarboxylic acids such as acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid, maleic acid, fumaric acid, citraconic acid, mesacone Examples thereof include dicarboxylic acids such as acid and itaconic acid, and dicarboxylic anhydrides such as maleic anhydride, fumaric anhydride, citraconic anhydride, mesaconic anhydride, and itaconic anhydride. These can be used alone or in combination of two or more.

  In addition to the sulfur-containing compound represented by the general formula (I) and the unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, the sulfur-containing copolymer contains other unsaturated compounds as monomer units. You may go out.

  Other unsaturated compounds that may be included as monomer units in the sulfur-containing copolymer (a3) include sulfur-containing compounds represented by general formula (I), and unsaturated carboxylic acids and / or unsaturated carboxylic acids. If it is an unsaturated compound copolymerizable with an acid anhydride, there will be no restriction | limiting in particular. Specifically, various unsaturated compounds listed as vinyl monomers for obtaining the above vinyl copolymer (a1), and γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl- o-phthalate, β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, (meth) acrylic acid-2- Hydroxy-3-chloropropyl, o-phenylphenol glycidyl ether (meth) acrylate, (meth) acrylic acid-2-hydroxy-3-phenoxypropyl, (meth) acrylic acid-2-[(1,1′-biphenyl) Oxy] ethoxy, (meth) acrylic acid-2- (2-methoxyethoxy) ethyl, the number of oxyethylene groups is 2 A is 23 (meth) acrylic acid methoxy polyoxyethylene (meth) -2-phenoxyethyl acrylate, (meth) -2- acrylate (2-phenoxyethyl - oxy) ethyl, and the like. From the viewpoint of further improving the refractive index, it is preferable to copolymerize (meth) acrylic acid-2-[(1,1′-biphenyl) oxy] ethoxy as another unsaturated compound component. These can be used individually by 1 type or in combination of 2 or more types.

  (A) The weight average molecular weight of the binder polymer (measured by gel permeation chromatography and converted to standard polystyrene) is the heat resistance, heat meltability, coatability, and the microlens array photosensitive element described later. From the viewpoints of film properties (characteristics that maintain a film-like form), solubility in a solvent, solubility in a developing solution in the development step, and the like, it is preferably 1,000 to 300,000, It is more preferable to set it to 000-150,000.

  Furthermore, it is preferable that (a) the binder polymer has an acid value so that it can be developed with various known developing solutions in the development step. For example, when the development is performed using an alkaline aqueous solution such as sodium carbonate, potassium carbonate, tetramethylammonium hydroxide, or triethanolamine, the acid value is preferably 50 to 260 mgKOH / g. When the acid value is 50 mgKOH / g or more, development tends to be easily performed. When the acid value is 260 mgKOH / g or less, the developer resistance (the portion that becomes a pattern without being removed by development is developed). The property of not being attacked by the liquid tends to be good. Moreover, when developing using the aqueous alkali solution which consists of water or aqueous alkali solution and 1 or more types of surfactant, it is preferable that an acid value shall be 16-260 mgKOH / g. When the acid value is 16 mgKOH / g or more, the development tends to be easy, and when the acid value is 260 mgKOH / g or less, the developer resistance tends to be good.

(B) Photopolymerizable unsaturated compound having an ethylenically unsaturated group As the photopolymerizable unsaturated compound having an ethylenically unsaturated group, for example, a polyhydric alcohol and an α, β-unsaturated carboxylic acid are reacted. 2,2-bis (4- (di (meth) acryloxypolyethoxy) phenyl) propane, a compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid, urethane Monomer, nonylphenyldioxylene (meth) acrylate, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o -Phthalate, β-hydroxypropyl-β '-(meth) acryloyloxyethyl-o-phthalate, (meth) acrylic acid Kill ester, and the like.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 propylene groups. ~ 14 polypropylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, trimethylolpropane diethoxytri (meth) acrylate , Trimethylolpropane triethoxytri (meth) acrylate, trimethylolpropanetetraethoxytri (meth) acrylate, trimethylolpropane pentaethoxytri (meth) acrylate, tetramethylolmethanetri (meth) ) Acrylate (pentaerythritol tri (meth) acrylate), tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like.

  Examples of the 2,2-bis (4- (di (meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4- (di (meth) acryloxydiethoxy) phenyl) propane, 2 , 2-bis (4- (di (meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4- (di (meth) acryloxypentaethoxy) phenyl) propane, 2,2-bis (4 -(Di (meth) acryloxydecaethoxy) phenyl) and the like.

  Examples of the compound obtained by reacting the glycidyl group-containing compound with an α, β-unsaturated carboxylic acid include trimethylolpropane triglycidyl ether tri (meth) acrylate and 2,2-bis (4- (meth)). (Acryloxy-2-hydroxy-propyloxy) phenyl and the like.

  Examples of the urethane monomer include (meth) acrylic monomers having an OH group at the β-position and isocyanate compounds such as isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate. Addition reaction product, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, ethylene oxide modified urethane di (meth) acrylate, ethylene oxide, propylene oxide modified urethane di (meth) acrylate and the like.

  Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid 2-ethylhexyl ester, and the like. .

  Said photopolymerizable unsaturated compound can be used individually by 1 type or in combination of 2 or more types.

  When (a) the sulfur-containing copolymer (a3) is used as the binder polymer, (b) the photopolymerizable unsaturated compound having an ethylenically unsaturated group is (B1) an ethylenically unsaturated group. And (B2) a photopolymerizable compound having at least two ethylenically unsaturated groups.

  (B1) As a photopolymerizable unsaturated compound having one ethylenically unsaturated group, for example, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyethyl- β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, (meth) acrylic acid-2-hydroxy-3-chloropropyl, o- Phenylphenol glycidyl ether (meth) acrylate, (meth) acrylic acid-2-hydroxy-3-phenoxypropyl, (meth) acrylic acid-2-[(1,1′-biphenyl) oxy] ethoxy, (meth) acrylic acid 2- (2-methoxyethoxy) ethyl, (meth) acrylic acid having 2 to 23 oxyethylene groups Acid methoxypolyoxyethylene, (meth) acrylic acid-2-phenoxyethyl, (meth) acrylic acid-2- (2-phenoxyethyl-oxy) ethyl, (meth) acrylic having 2 to 23 oxyethylene groups The acid phenoxy polyoxyethylene is mentioned. Among them, as the component (B1), from the viewpoint of further improving the refractive index, the number of (meth) acrylic acid-2-[(1,1′-biphenyl) oxy] ethoxy or oxyethylene groups is 2 to 5. (Meth) acrylic acid phenoxypolyoxyethylene is preferred. Moreover, the sulfur containing compound represented by the said general formula (I) can be used as (B1) component. Furthermore, the above-mentioned other unsaturated compounds can also be used as the component (B1). These compounds can be used individually by 1 type or in combination of 2 or more types.

(B2) Examples of the photopolymerizable unsaturated compound having at least two ethylenically unsaturated groups include compounds obtained by reacting polyhydric alcohols with α, β-unsaturated carboxylic acids, and glycidyl groups. Polyhydric thiols such as compounds obtained by reacting containing compounds with α, β-unsaturated carboxylic acids, urethane monomers, bis (4-methacryloylthiophenyl) sulfide, bis [(2-methacryloylthio) ethyl] sulfide, etc. A compound obtained by reacting an α, β-unsaturated carboxylic acid with α is preferably used.
These compounds exemplified as the component (B2) can be used singly or in combination of two or more.

(C) Photopolymerization initiator Examples of photopolymerization initiators that generate free radicals with actinic rays include benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′—. Tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] (“Irgacure -OXE01 ", trade name of Ciba Specialty Chemicals Co., Ltd.), ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime ) (Irgacure-OXE02, Ciba Specialty Chemicals Co., Ltd. trade name), 2-benzyl-2-dimethylamino -1- (4-morpholinophenyl) -butan-1-one (“Irgacure-369”, trade name of Ciba Specialty Chemicals), 2-methyl-1- [4- (methylthio) phenyl] -2- Aromatic ketones such as morpholino-propan-1-one (“Irgacure-907”, Ciba Specialty Chemicals Co., Ltd.); 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1 , 2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphtho Quinones such as 2,3-dimethylanthraquinone; benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether and benzoin phenyl ether; benzoin compounds such as benzoin, methyl benzoin and ethyl benzoin; benzyl derivatives such as benzyl dimethyl ketal; 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4 2,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, etc. 4,5-triarylimidazole dimer; 9- Examples include acridine derivatives such as phenylacridine and 1,7-bis (9,9′-acridinyl) heptane; N-phenylglycine, N-phenylglycine derivatives, and coumarin compounds.

  In the 2,4,5-triarylimidazole dimer, the substituents substituted with two 2,4,5-triarylimidazoles may be the same or different. Moreover, you may combine a thioxanthone type compound and a tertiary amine compound like the combination of diethyl thioxanthone and dimethylaminobenzoic acid.

In addition, from the viewpoint of adhesion and sensitivity in the photolithography process, 2,4,5-triarylimidazole dimer is preferable as the component (c), and 1 from the viewpoint of visible light transmittance when a microlens is used. , 2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] is more preferable.
Said photoinitiator can be used individually by 1 type or in combination of 2 or more types.

  In the photosensitive resin composition for lenses, the blending ratio of the (a) binder polymer is preferably 20 to 90 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b), and 30 to 85 parts. It is more preferable to set it as a mass part, It is especially preferable to set it as 35-80 mass parts, It is very preferable to set it as 40-75 mass parts. When the blending ratio is 20 parts by mass or more, the coating property, heat melting property, or film property when a lens photosensitive element described later tends to be good, and by 90 parts by mass or less. , Photocurability or heat resistance tends to be good.

  Further, the blending ratio of the photopolymerizable unsaturated compound having (b) an ethylenically unsaturated group in the photosensitive resin composition for a lens is 10 with respect to 100 parts by mass of the total amount of the components (a) and (b). It is preferable to set it to -80 mass parts, It is more preferable to set it as 15-70 mass parts, It is especially preferable to set it as 20-65 mass parts, It is very preferable to set it as 25-60 mass parts. When the blending ratio is 10 parts by mass or more, the photocurability or heat resistance tends to be good, and when it is 80 parts by mass or less, the coating property, the heat melting property, or the photosensitive element for a lens is obtained. There exists a tendency for film property to become favorable.

  Moreover, in the photosensitive resin composition for lenses, the blending ratio of the (c) photopolymerization initiator is 0.05 to 20 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). Is preferable, 0.1 to 15 parts by mass is more preferable, and 0.15 to 10 parts by mass is particularly preferable. By making this blending ratio 0.05 parts by mass or more, photocuring tends to be good, and by 20 parts by mass or less, in the curing step, on the actinic ray irradiated surface of the lens-forming resin layer 6a. The increase in the absorption of the active light is prevented, and the internal photocuring is prevented from becoming insufficient.

  For the photosensitive resin composition for lenses, as necessary, adhesion imparting agents such as silane coupling agents, leveling agents, plasticizers, fillers, antifoaming agents, flame retardants, stabilizers, antioxidants, perfumes. , A thermal crosslinking agent, a polymerization inhibitor and the like can be contained. These can be used individually by 1 type or in combination of 2 or more types. Moreover, these compounding ratios can be 0.01-20 mass parts with respect to 100 mass parts of total amounts of (a) and (b) component, respectively.

<Protective material>
In the method for manufacturing an optical waveguide with a lens according to the present invention, a resist (not shown) may be provided in parallel with the lens 6. The resist is a protective material that protects the lens 6 and prevents the lens 6 from being damaged. It is preferable that a plurality of resists are provided, and each lens 6 is disposed so as to be sandwiched between a pair of resists. That is, it is preferable that a pair of resists be disposed on both sides of the lens 6 in the optical waveguide plane direction.

Each resist has a thickness equal to or greater than the thickness of the lens 6 and is preferably thicker than the thickness of the lens 6 so that the lens 6 can be appropriately protected.
The resist is preferably formed separately after forming the lens 6 in order to make it easier to make the resist thicker than the lens 6. Specifically, a resin layer is laminated on the surface on which the lens 6 is provided so as to cover the lens 6, and then each resist is formed by removing the resin layer other than the portions where the resist is to be formed. Therefore, a photosensitive resin or a thermosetting resin can be used as the resist material, but it is preferable that the photosensitive resin is used and formed by photolithography. Since both the lens 6 and the resist are formed by photolithography, the alignment accuracy between the resist and the lens 6 can be improved.

  Further, as a protective material for protecting the lens 6, a dummy lens may be used instead of the resist. The dummy lens is formed together with the lens 6 from the lens forming resin layer 6a (see FIG. 2), for example, by photolithography. As a result, it is not necessary to add a special process for forming the protective material, and it is possible to improve the alignment accuracy of the lens 6 and the dummy lens. Since the formation position of the dummy lens is the same as the formation position of the resist, the description thereof is omitted.

  The thickness of the dummy lens may be equal to or greater than the thickness of the lens 6, but is preferably larger than the thickness of the lens 6. As a method for making the thickness of the dummy lens larger than the thickness of the lens 6, for example, the irradiation amount of the actinic ray to the formation planned position of the dummy lens is made larger than the irradiation amount of the actinic ray to the formation planned position of the lens 6, For example, the degree of curing of the planned formation position of the dummy lens may be larger than the degree of curing of the planned formation position of the lens 6. The dummy lens preferably has a lens surface that bulges in a convex shape like the lens 6, but is not limited to this configuration.

  In addition, when the board | substrate 1 is an electrical wiring board which has an electrical wiring, it is preferable that a resist is laminated | stacked on at least one part of an electrical wiring, and is used as a protective resist which protects an electrical wiring. In addition, it is preferable that a part of the surface of the electric wiring is covered with a metal protective film such as gold plating and a resist is laminated on the other surface. With such a configuration, the amount of plating for protecting the electrical wiring can be suppressed. A dummy lens and an elongated resist may be similarly laminated on the electric wiring and used as a member for protecting the electric wiring.

[Electric wiring]
In the method for manufacturing an optical waveguide with a lens according to the present invention, when various optical elements are mounted on the back surface of the substrate 1, electrical wiring may be provided on the back surface of the substrate 1.

[Electrical wiring protective layer]
The core forming resin is transparent to the optical signal to be used, and can form a pattern by actinic rays, and if it can be used as an electric wiring protective layer, the electric wiring protective layer that protects the electric wiring described above Can be used as

[Cover layer]
The optical waveguide manufactured in the present invention may further have a lid material layer.
The lid material layer is preferably provided on the upper cladding layer 4 and can suppress warping of the optical waveguide.
Specific examples of the lid material layer include a base material and an adhesive layer, and the base material may be the same as that of the substrate 1 described above. The adhesive layer is not particularly limited as long as it has adhesion to the upper clad layer 4, but a tensile elastic modulus of 100 MPa to 2 GPa is preferable from the viewpoint of flexibility. When it is provided from the viewpoint of suppressing warping without requiring flexibility, it is preferable that the tensile elastic modulus is 100 MPa to 50 GPa. The thickness of the adhesive layer is not particularly limited, but may be 5 μm to 25 μm from the viewpoint of bending resistance, and more preferably 5 μm to 15 μm in order to obtain stable flexibility. Further, it is preferable to use a material having a lower elastic modulus than that of the substrate 1 because the bending resistance is further improved. When it is provided from the viewpoint of suppressing warpage without requiring flexibility, the thickness may be 10 μm to 1 mm, and more preferably 25 μm to 1 mm in order to obtain stable warpage suppression. As the lid material layer, materials listed in [Substrate] within the above-mentioned range and those provided with an adhesive layer on the material are preferably raised. A coverlay film generally used for flexible electrical wiring can also be used.

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 a resin film for forming a cladding layer>
[Production of (A) (meth) acrylic polymer (base polymer)]
46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate were weighed in a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 47 parts by weight of methyl methacrylate, 33 parts by weight of butyl acrylate, 16 parts by weight of 2-hydroxyethyl methacrylate, 14 parts by weight of methacrylic acid, 2,2′-azobis (2,4-dimethylvaleronitrile ) A mixture of 3 parts by mass, 46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 65 ° C. for 3 hours, and further stirring at 95 ° C. for 1 hour. A) A (meth) acrylic polymer solution (solid content: 45% by mass) was obtained.

[Measurement of weight average molecular weight]
(A) The result of having measured the weight average molecular weight (standard polystyrene conversion) of (meth) acrylic polymer using GPC ("SD-8022", "DP-8020", and "RI-8020" by Tosoh Corp.). 3.9 × 10 ⁴ . The column used was “Gelpack GL-A150-S” and “Gelpack GL-A160-S” manufactured by Hitachi Chemical Co., Ltd.
[Measurement of acid value]
As a result of measuring the acid value of (A) (meth) acrylic polymer, 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) (meth) acrylic polymer 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.

[Preparation of resin varnish for forming clad layer]
As a base polymer, 84 parts by mass (solid content 38 parts by mass) of the (A) (meth) acrylic polymer solution (solid content 45% by mass), (B) urethane (meth) acrylate having a polyester skeleton as a photocuring component ( Shin-Nakamura Chemical Co., Ltd. “U-200AX”) 33 parts by mass, and urethane (meth) acrylate having a polypropylene glycol skeleton (Shin-Nakamura Chemical Co., Ltd. “UA-4200”) 15 parts by mass, (C ) Polyfunctional block isocyanate solution (solid content 75% by mass) obtained by protecting isocyanurate-type trimer of hexamethylene diisocyanate with methyl ethyl ketone oxime as a thermosetting component (Sumijour BL3175 manufactured by Sumika Bayer Urethane Co., Ltd.) 20 1 part by mass (solid content 15 parts by mass), (D) 1- [4- 2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (“Irgacure 2959” manufactured by Ciba Japan Co., Ltd.), 1 part by weight, bis (2,4,6-trimethylbenzoyl) ) 1 part by mass of phenylphosphine oxide (“Irgacure 819” manufactured by Ciba Japan Co., Ltd.) and 23 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent for dilution were mixed with stirring. After pressure filtration using a polyflon filter having a pore size of 2 μm (“PF020” manufactured by Advantech Toyo Co., Ltd.), degassing was performed under reduced pressure to obtain a resin varnish for forming a cladding layer.

[Preparation of resin film for forming clad layer]
The resin varnish for forming a clad layer obtained above is coated on a non-treated surface of a PET film (“Cosmo Shine A4100” manufactured by Toyobo Co., Ltd., thickness 50 μm) as a support film. MC, manufactured by Hirano Tech Seed Co., Ltd., dried at 100 ° C. for 20 minutes, and then a surface release treated PET film (“Purex A31” manufactured by Teijin DuPont Films Co., Ltd., thickness 25 μm) is pasted as a protective film. A resin film for forming a cladding layer was obtained.
At this time, the thickness of the resin layer formed from the clad layer forming resin varnish can be arbitrarily adjusted by adjusting the gap of the coating machine, and the film thickness will be described later.

<Preparation of core layer forming resin film>
(A) As a base polymer, 26 parts by mass of a phenoxy resin (trade name: Phenotote YP-70, manufactured by Toto Kasei Co., Ltd.), and (B) 9,9-bis [4- (2- Acrylyloxyethoxy) 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 parts by mass, (C) 1 part by mass of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (trade name: Irgacure 819, manufactured by Ciba Specialty Chemicals) -[4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (trade name: Irgacu 2959, manufactured by Ciba Specialty Chemicals Co., Ltd.) 1 part by weight, core layer in the same manner and conditions as in the above-mentioned preparation of the clad layer forming resin varnish except that 40 parts by weight of propylene glycol monomethyl ether acetate was used as the organic solvent A forming resin varnish was prepared. Thereafter, pressure filtration and degassing under reduced pressure were performed in the same manner and conditions as described above.
On the non-treated surface of the PET film (trade name: Cosmo Shine A1517, manufactured by Toyobo Co., Ltd., thickness: 16 μm), which is a support film, the core layer-forming resin varnish obtained above and After applying and drying in the same manner, a release PET film (trade name: PUREX A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) is attached as a protective film so that the release surface is on the resin side. A resin film for forming a core layer was obtained.
At this time, the thickness of the resin layer formed from the core layer forming resin varnish can be arbitrarily adjusted by adjusting the gap of the coating machine, and the film thickness will be described later.

<Production of photosensitive element for lens>
A flask equipped with a stirrer, reflux condenser, inert gas inlet and thermometer was charged with 190 parts by mass of propylene glycol monomethyl ether acetate, heated to 80 ° C. in a nitrogen gas atmosphere, and the reaction temperature was raised to 80 ° C. 1. While maintaining, 10 parts by weight of methacrylic acid, 1 part by weight of n-butyl methacrylate, 74 parts by weight of benzyl methacrylate, 15 parts by weight of 2-hydroxyethyl methacrylate, and 2,2′-azobis (isobutyronitrile) 5 parts by mass were uniformly dropped over 4 hours. After completion of the dropping, stirring was continued at 80 ° C. for 6 hours to obtain a binder polymer (a) solution (solid content: 35% by mass) having a weight average molecular weight of about 30,000.
Next, 200 parts by mass (solid content: 70 parts by mass) of the binder polymer (a) solution (solid content 35% by mass) and 2,2-bis (4- (di (meth) acryloxypolyethoxy) phenyl) 8 parts by mass of propane, 22 parts by mass of β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, 2.1 parts by mass of 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, Add 0.33 parts by mass of N, N′-tetraethyl-4,4′-diaminobenzophenone, 0.25 parts by mass of mercaptobenzimidazole, 8 parts by mass of (3-methacryloylpropyl) trimethoxysilane, and 30 parts by mass of methyl ethyl ketone. Was mixed for 15 minutes to prepare a photosensitive resin composition solution for lenses.

  A polyethylene terephthalate film having a thickness of 16 μm was used as a support film, and the photosensitive resin composition solution for lenses obtained above was uniformly applied on the support film using a comma coater, and a hot air convection type at 100 ° C. The solvent was removed by drying for 3 minutes with a dryer to form a lens-forming resin layer 6a. The obtained lens forming resin layer 6a had a thickness of 30 μm. Next, a polyethylene terephthalate film having a thickness of 25 μm was further bonded as a cover film on the obtained lens-forming resin layer 6a to produce a lens photosensitive element.

<Creation of optical waveguide>
[Batch formation of lens and lower cladding layer]
Using a 150 mm × 150 mm polyimide film (polyimide; Upilex RN (manufactured by Ube Nitto Kasei Co., Ltd.), thickness: 25 μm) as the substrate 1, while peeling the cover film of the lens photosensitive element on one surface thereof, Using a laminator (manufactured by Hitachi Chemical Co., Ltd., trade name “HLM-1500 type”) so that the lens forming resin layer 6a is in contact, roll temperature is 120 ° C., substrate feed speed is 1 m / min, and pressure is applied (cylinder pressure). ) A lens forming resin layer 6a with a support film was laminated by laminating under conditions of 4 × 10 ⁵ Pa.
Subsequently, after peeling off the protective film of the 15 μm-thick clad layer-forming resin film obtained above on the other surface of the substrate 1, a vacuum pressure laminator (manufactured by Meiki Seisakusho, MVLP-500) After vacuuming to 500 Pa or less, lamination was performed by thermocompression bonding under conditions of a pressure of 0.4 MPa, a temperature of 110 ° C., and a pressing time of 30 seconds to form a clad layer-forming resin layer 2a (FIG. 2). (See (a)).

Subsequently, after peeling off the support film from the lens forming resin layer 6a, a lens photomask having an opening with an opening width = 100 μm was disposed on the lens forming resin layer 6a side.
Then, the ultraviolet ray exposure machine (model name: EXM-1172, manufactured by Oak Manufacturing Co., Ltd.) irradiates ultraviolet rays (wavelength 365 nm) at 0.3 J / cm ² to the lens forming resin layer 6a side through a photomask. At the same time, irradiation is performed at 3.0 J / cm ² from the support film side of the resin film for forming the clad layer, and then etching is performed using a 1.0% by mass aqueous solution of potassium carbonate to develop a resist for lens formation. 6b and the lower clad layer 2 were formed (see FIG. 2B).
Further, the lens forming resist 6b was further heated and melted to obtain a lens 6 having a convex surface, and the lower clad layer 2 was heated and cured (see FIG. 2C).

[Formation of optical signal transmission core pattern]
On the lower clad layer 2 formed above, after the protective film is peeled off the 50 μm-thick core layer-forming resin film obtained above, a roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.) And laminating at a pressure of 0.4 MPa, a temperature of 50 ° C., and a laminating speed of 0.2 m / min, and then using the above-described vacuum pressure laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) to 500 Pa or less. After vacuuming, thermocompression bonding was performed under the conditions of a pressure of 0.4 MPa, a temperature of 70 ° C., and a pressurization time of 30 seconds to form a core-forming resin layer 3a (see FIG. 2D).

Subsequently, using a negative photomask for forming the optical signal transmission core pattern 3 and the ultraviolet exposure machine, ultraviolet rays (wavelength 365 nm) are irradiated at 0.8 J / cm ² from the support film side, and then 80 Heating was performed after exposure for 5 minutes at ° C. As shown in FIGS. 1 and 2, the optical signal transmission core pattern 3 has four cores extending to the center of the optical waveguide.
Thereafter, the PET film as the support film was peeled off and 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 formed the optical signal transmission core pattern 3 (refer FIG.2 (e)).

[Formation of upper cladding layer]
After removing the protective film from the 55 μm-thick clad layer forming resin film obtained above from the obtained optical signal transmission core pattern 3, a vacuum pressure laminator (manufactured by Meiki Seisakusho Co., Ltd., MVLP) -500), and after vacuuming to 500 Pa or less, lamination was performed by thermocompression bonding under conditions of a pressure of 0.4 MPa, a temperature of 110 ° C., and a pressurization time of 30 seconds.
Subsequently, ultraviolet rays (wavelength 365 nm) were irradiated at 3.0 J / cm ² from the support film side of the resin film for forming the clad layer using the UV exposure machine, and the support film was peeled off, followed by exposure at 80 ° C. for 5 minutes. Post-heating was performed to form the upper cladding layer 4 (see FIG. 2F).

[Formation of optical path conversion mirror]
A 45 ° optical path conversion mirror 5 was formed using a dicing saw (DAC552, manufactured by Disco Corporation) from the upper clad layer 4 side of the obtained optical waveguide to obtain an optical waveguide with a lens.

[Measurement of optical loss]
An optical signal of 850 nm is incident on the optical waveguide using the optical fiber A (GI50, NA = 0.2), transmitted through the optical signal transmission core pattern 3, reflected by the optical path conversion mirror 5, and transmitted through the lens 6. The optical loss (A) when the output optical signal was received using the optical fiber B (GI50, NA = 0.2) on the mirror center point was measured. At this time, the distance between the surface of the substrate 1 and the optical fiber B was 30 μm. Next, the optical path conversion mirror 5 was cut using the above dicing saw to obtain an optical waveguide without a mirror. Next, using the optical fiber A and the optical fiber B, the optical fiber A is aligned on the incident portion side in the coaxial direction with the optical signal transmission core pattern 3, and the optical fiber B is aligned on the emission portion side, and the optical loss (B ) Was measured.
From the above, the light loss (C) from the optical path conversion mirror 5 through the lens 6 was calculated according to the following equation.
(Formula) (C) = (A)-(B)
The optical loss (C) in the optical waveguide with a lens obtained in Example 1 was 1.82 dB.
The angle formed by the optical path conversion mirror 5 and the surface of the substrate 1 was measured and found to be 45.1 °.

Comparative Example 1
After performing the 2nd process-the 5th process, except having formed the lens by performing the 1st process, the optical waveguide with a lens was created like Example 1, and the optical loss was measured.
The optical loss (C) in the optical waveguide with a lens obtained in Comparative Example 1 was 2.05 dB.
The angle formed by the optical path conversion mirror 5 and the surface of the substrate 1 was measured and found to be 47.2 °.

1. Substrate 2. Lower cladding layer 2a. 2. Clad layer forming resin layer Optical signal transmission core pattern 3a. 3. Core-forming resin layer 4. Upper clad layer 5. Optical path conversion mirror Lens 6a. Lens forming resin layer 6b. 9. Lens forming resist Optical waveguide

Claims (8)

  A first step of forming a lens on one side of the substrate; a second step of forming a lower cladding layer on the other side of the substrate; and a first step of forming a core pattern for transmitting an optical signal on the lower cladding layer. 3 steps, a fourth step of forming an upper clad layer on the optical signal transmission core pattern, and a fifth step of forming an optical path conversion mirror on the optical signal transmission core pattern, The manufacturing method of the optical waveguide with a lens by which this 5th process is performed after 1 process is completed.   The manufacturing method of the optical waveguide with a lens according to claim 1, wherein the first step is performed simultaneously with any one of the second step to the fourth step.   The manufacturing method of the optical waveguide with a lens according to claim 2, wherein the first step is performed simultaneously with the second step or the third step.   The manufacturing method of the optical waveguide with a lens according to claim 3, wherein the first step is performed simultaneously with the second step.   The method for manufacturing an optical waveguide with a lens according to claim 1, wherein the first step is performed by photolithography.   The method of manufacturing an optical waveguide with a lens according to claim 1, wherein the fifth step is performed by cutting an optical signal transmission core pattern.   The method for manufacturing an optical waveguide with a lens according to claim 1, wherein the substrate is a polyimide substrate.   Furthermore, it has the 6th process of arranging the resist or dummy lens which has thickness more than lens thickness on the one surface of the said board | substrate with the said lens, The optical waveguide with a lens in any one of Claims 1-7. A method for manufacturing a waveguide.

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