JP6003147B2 - SUBSTRATE WITH LENS AND ITS MANUFACTURING METHOD, OPTICAL WAVEGUIDE WITH LENS AND ITS MANUFACTURING METHOD - Google Patents

Description

  The present invention relates to a substrate with a lens in which an optical lens is formed on the substrate, a method for manufacturing the same, an optical waveguide with a lens having the substrate with a lens, and a method for manufacturing the same.

In IC technology and LSI technology, in order to improve operation speed and integration, a part of the electrical wiring on the electrical wiring board is replaced with optical wiring such as an optical fiber or an optical waveguide, and the optical signal is used instead of the electrical signal. Things have been done.
For example, Patent Document 1 discloses that an optical waveguide film is installed above an IC chip having an optical element on the surface, and optical communication is performed between the IC chip and the optical waveguide film. However, when optical communication is performed between a substrate provided with optical communication means such as an optical element and an optical communication means such as an optical waveguide as in Patent Document 1, these optical communication means are positioned with high accuracy. There is a problem that optical communication cannot be performed without mounting.

In order to solve this problem, a microlens is provided on the surface of the substrate.
For example, Patent Document 2 discloses a lens-attached substrate in which a microlens is installed on the surface of a transparent substrate. In order to manufacture this lens-attached substrate, a photosensitive resin resist is formed on the surface of the transparent substrate, and a light shielding film having an opening is formed on the back surface of the substrate. Next, light is irradiated from the light shielding film side to expose a portion of the photosensitive resin resist that is located at a position facing the opening of the light shielding film, and then developed to form a cylindrical resist structure. Thereafter, the resist structure is heated, and the surface of the resist structure is heated to produce a microlens.

JP 2006-11210 A JP 2004-361858 A

When a lens is formed on the surface of a substrate as in Patent Document 2, there is a problem that the lens and the substrate cannot be firmly fixed. Further, as described above, since the photosensitive resin resist on the substrate surface is exposed by irradiating light from the back side of the substrate, there is a problem that the lens can be installed only on the transparent substrate that transmits the light and the optical signal wavelength. is there. Even a substrate that transmits an optical signal wavelength has poor light transmission, leading to light propagation loss.
Instead of irradiating light from the back surface side of the substrate as described above, it is also conceivable to irradiate light from the front surface side of the substrate through a mask. However, also in this case, the lens and the substrate cannot be firmly fixed, and in order to transmit the light incident on the lens from the front surface side of the substrate to the back surface side of the substrate, the transparent substrate that transmits the optical signal wavelength is used. However, there is a problem that only a lens can be installed, and even a substrate that transmits an optical signal wavelength has a problem that it leads to a light propagation loss if its transparency is poor.
The present invention has been made to solve the above-described problems, and has a high fixing strength between the lens and the substrate, a small optical loss, and it is possible to use either a transparent substrate or a non-transparent substrate for the optical signal wavelength. It is an object to provide an electric wiring board with a lens and a manufacturing method thereof, an optical waveguide with a lens including the electric wiring board, and a manufacturing method thereof.

  As a result of intensive studies, the present inventors have arranged the base end side of the lens member inside the through hole of the substrate, and protruded the tip end side of the lens member from the substrate to form a convex surface on the protruding portion. And it discovered that the said subject can be solved by arrange | positioning a transparent member so that a space | gap may not arise in the said through hole, and it came to this invention.

That is, the present invention provides the following [1] to [12].
[1] A substrate having a through hole, a lens member extending from the inside of the through hole to the outside of one surface of the substrate, and the other of the substrates in the through hole rather than the lens member A substrate with a lens having a transparent member on the surface side, wherein the base end surface of the lens and the base end surface of the transparent member are in contact with each other inside the through hole, and the front end surface of the lens is A lens-fitted substrate having a convex lens surface that protrudes from the through hole and is convexly curved.
[2] The lens-attached substrate according to [1], wherein the substrate is an electrical wiring board having electrical wiring.
[3] The lens-attached substrate according to [1] or [2], wherein the front end surface of the transparent member is a non-lens surface parallel to the surface of the substrate.
[4] The lens-attached substrate according to [1] or [2], wherein a tip surface of the transparent member is a convex lens surface protruding from the through hole.
[5] The method for manufacturing a lens-attached substrate according to any one of [1] to [4], including the following steps 1 to 4.
Step 1: The photosensitive resin composition for a lens member is laminated on one surface of the substrate and filled in the through hole, and the transparent resin composition is laminated on the other surface of the substrate and in the through hole. Step of filling Step 2: Irradiating actinic rays from the other surface side of the substrate to expose and cure the photosensitive resin composition for the lens member, and photocuring or thermosetting the transparent resin composition Step 3: Step of developing and removing an uncured portion of the photosensitive resin composition for a lens member to form a columnar transparent member extending from the inside of the through hole to the outside of one surface of the substrate. 4: Heating the columnar transparent member and dripping the tip of the columnar transparent member protruding from the substrate to form a convex lens surface [6] In the step 2, the substrate A photosensitive resin composition for a lens member is formed by disposing a mask having an opening at a position facing the through hole on the other surface side and irradiating actinic rays from the other surface side through the mask. The method for producing a substrate with a lens according to [5], wherein the object is exposed and cured.
[7] The substrate has a light-shielding property, and in the step 2, by irradiating actinic rays from the other surface side of the substrate, the through-holes in the photosensitive resin composition for the lens member The manufacturing method of the board | substrate with a lens of Claim 5 which exposes and cures the opposing part.
[8] The method for producing a lens-attached substrate according to any one of [5] to [7], wherein the transparent resin composition is a photosensitive resin composition.
[9] The lens-attached substrate according to any one of [1] to [3], a lower clad layer existing on a surface of the substrate on the other end side of the through hole, and existing on the lower clad layer An optical waveguide with a lens having a core layer to be formed, an upper clad layer existing on the core layer, and a mirror existing in a position facing the lens in the core layer.
[10] The optical waveguide with a lens according to [9], wherein a part of the lower cladding layer constitutes the transparent member.
[11] A method for manufacturing an optical waveguide with a lens, wherein an optical waveguide member is formed on the other surface of the substrate with a lens according to any one of [1] to [3].
[12] The method for manufacturing an optical waveguide with a lens according to [10], including the following steps A to F.
Step A: Filling the through-hole with the photosensitive resin composition for a lens from one side of the through-hole of the substrate having a through-hole and having a light-shielding property, and the other side of the through-hole Step B: forming a transparent resin composition in the through hole and on the other surface Step B: Exposing the photosensitive resin composition for a lens by irradiating actinic rays from the other surface side of the substrate Step of forming the lower cladding layer by photocuring or thermosetting the transparent resin composition while being cured Step C: developing and removing uncured portions of the photosensitive resin composition for lenses, and the inside of the through hole Forming a columnar transparent member extending over the outside of one surface of the substrate from step D: heating the columnar transparent member and projecting from the substrate out of the columnar transparent member A step of dripping the tip portion to form a convex lens surface Step E: forming a core layer on the surface of the lower clad layer and forming an upper clad layer on the surface of the core layer Step F: the step of forming the core layer Forming a mirror at a position facing the through hole

  According to the present invention, it is possible to obtain a lens-equipped substrate and a lens-equipped optical waveguide that have a high fixing strength between the lens and the substrate, have little optical loss, and can use either a transparent substrate or a non-transparent substrate.

1A is a plan view of the lens-equipped substrate 1 according to the first embodiment, FIG. 1B is a cross-sectional view taken along line BB in FIG. 1A, and FIG. It is a front view of the lens member of 1 (a). It is sectional drawing which shows an example of the manufacturing method of the board | substrate with a lens of FIG. It is sectional drawing of 1 A of board | substrates with a lens which concerns on 2nd Embodiment. 4A is a perspective view of a lens-equipped substrate (lens-attached electrical wiring substrate) 1B according to the third embodiment, and FIG. 4B is a cross-sectional view taken along line BB in FIG. 4A. is there. 5A is a plan view of the lens-equipped substrate 1B as viewed from above in FIG. 4A, and FIG. 5B is a plan view of the lens-equipped substrate 1B as viewed from below in FIG. 4A. It is sectional drawing of 1C of board | substrates with a lens which concerns on 4th Embodiment. It is sectional drawing of the board | substrate with a lens (electric wiring board with a lens) 1D (1E) based on 5th Embodiment. FIG. 8A is a perspective view of the optical waveguide 20 with a lens according to the seventh embodiment, FIG. 8B is a plan view of the optical waveguide 20 with a lens, and FIG. It is sectional drawing. FIG. 9 is a cross-sectional view illustrating a method for manufacturing the optical waveguide with lens 20 of FIG. FIG. 10A is a perspective view of the optical waveguide 30 with a lens according to the eighth embodiment, FIG. 10B is a plan view of the optical waveguide 30 with a lens, and FIG. 10C is the perspective view of FIG. It is sectional drawing which follows CC line. It is sectional drawing of the optical waveguide 40 with a lens which concerns on 9th Embodiment.

[Substrate with lens and manufacturing method thereof]
<Lens substrate>
The substrate with a lens of the present invention includes a substrate having a through hole, a lens member extending from the inside of the through hole to the outside of one surface of the substrate, and the lens member out of the inside of the through hole. A transparent member present on the other surface side of the substrate, and a base end surface of the lens and a base end surface of the transparent member are in contact with each other inside the through-hole, The front end surface of the lens is a convex lens surface that protrudes from the through hole and is curved convexly.
According to the substrate with a lens of the present invention, since the base end side of the lens member extends into the through hole of the substrate, the fixing strength of the lens member to the substrate is high. Moreover, since the front end side of the lens member protrudes from the substrate, the distance from the optical communication target can be shortened by that amount, and the convex lens surface at the front end can be condensed, so that there is little light loss. Furthermore, since the transparent member is arranged so that no gap is generated in the through hole, there is little light loss in the through hole. Furthermore, since optical communication is performed through the transparent member and the lens member, optical communication can be performed with little optical loss even when the substrate is not a transparent substrate.
The substrate with lens of the present invention may be an electrical wiring board having electrical wiring. Further, the front end surface of the transparent member may be a non-lens surface parallel to the surface of the substrate, or may be a convex lens surface protruding from the through hole.
Next, each member of the substrate with lens will be described.

(substrate)
The material of the substrate is not particularly limited. For example, glass epoxy resin substrate, ceramic substrate, glass substrate, silicon substrate, plastic substrate, metal substrate, substrate with resin layer, substrate with metal layer, plastic film, plastic with resin layer Examples thereof include a film, a plastic film with a metal layer, and an electric wiring board. In particular, it is preferable to have a light shielding effect against actinic rays for photocuring a photosensitive resin composition for a lens member described later.
For example, when the actinic ray for photocuring the transparent resin is ultraviolet light, a metal substrate, a plastic substrate that does not transmit ultraviolet light, a glass epoxy resin substrate, and the like are preferably used. However, when a mask described later is used, the light shielding effect may not be provided.
Although there is no restriction | limiting in particular in the thickness of a board | substrate, From the viewpoint of ensuring intensity | strength and reduction of the optical loss by shortening of an optical path, it is preferable that the thickness of a board | substrate is 5 micrometers-1 mm, and it is more preferable that they are 10 micrometers-100 micrometers.

(Through hole)
One or more through holes may be present in the substrate, and can be suitably formed by, for example, drilling or laser processing. Moreover, the through hole with a metal layer formed by vapor-depositing, sputtering, plating, etc. on the side surface of the through hole may be used. When a metal foil is provided on the substrate surface around the through hole, it can be used as a light shielding part.
The shape in plan view orthogonal to the depth direction of the through hole is not particularly limited, and may be a circular shape such as a perfect circle or an ellipse; a polygonal shape such as a triangle, a quadrangle, a pentagon, or a hexagon. Further, the space in the through hole may be on a column having the same shape regardless of the position in the depth direction, or may have a tapered shape that becomes smaller as it moves in the depth direction.
Area of the plan view shape of the through-holes may be any range not affecting the optical loss is preferably 600～200000Myuemu ^2, more preferably 2500~35000μm ^2.

(Lens member)
The material of the lens member is not particularly limited as long as it is transparent to the optical signal, but is preferably a cured product of the photosensitive resin composition from the viewpoint of the manufacturing method described later.
The photosensitive resin composition preferably contains (a) a binder polymer, (b) a photopolymerizable unsaturated compound having an ethylenically unsaturated group, and (c) a photopolymerization initiator.

  (A) As a binder polymer, a vinyl copolymer is mentioned, for example, Specifically, what was obtained by polymerizing the following vinyl monomer is mentioned. For example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, iso-propyl acrylate , Iso-propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, iso-butyl acrylate, iso-butyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, tert-butyl acrylate, Tert-butyl methacrylate, pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate, heptyl acrylate, heptyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, acrylate Chill, octyl methacrylate, nonyl acrylate, nonyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tetradecyl acrylate, tetradecyl methacrylate, hexadecyl acrylate, hexadecyl methacrylate, octadecyl acrylate, Octadecyl methacrylate, eicosyl acrylate, eicosyl methacrylate, docosyl acrylate, docosyl methacrylate, cyclopentyl acrylate, cyclopentyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, cycloheptyl acrylate, cycloheptyl methacrylate, benzyl acrylate, Benzyl methacrylate, phenyl acrylate, phenyl methacrylate, methoxyethyl acrylate, methacrylate Methoxyethyl acid, methoxydiethylene glycol acrylate, methoxydiethylene glycol methacrylate, methoxydipropylene glycol acrylate, methoxydipropylene glycol methacrylate, methoxytriethylene glycol acrylate, methoxytriethylene glycol methacrylate, 2-hydroxyethyl acrylate, methacryl 2-hydroxyethyl acid, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, 2-chloroethyl acrylate, 2-methacrylic acid 2- Chloroethyl, 2-fluoroethyl acrylate, 2-fluoroethyl methacrylate, acrylic 2-cyanoethyl phosphate, 2-cyanoethyl methacrylate, styrene, α-methylstyrene, cyclohexylmaleimide, dicyclopentanyl acrylate, dicyclopentanyl methacrylate, vinyl toluene, vinyl chloride, vinyl acetate, N-vinyl pyrrolidone, Examples include butadiene, isoprene, chloroprene, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile and the like. These may be polymerized singly or in combination of two or more.

  Further, (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, an acid anhydride, etc. The side chain obtained by the addition reaction of a compound having one functional group such as an oxirane ring, isocyanate group, hydroxyl group, carboxyl group and at least one ethylenically unsaturated group that is bonded by reaction is ethylenic. A radically polymerizable copolymer having an unsaturated group can also be used.

  Examples of the vinyl monomer used in the production of the vinyl copolymer having a functional group such as carboxyl group, hydroxyl group, amino group, isocyanate group, oxirane ring, and acid anhydride include acrylic acid, methacrylic acid, and maleic acid. , Fumaric acid, itaconic acid, cinnamic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, ethyl isocyanate, glycidyl acrylate, glycidyl methacrylate, 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 isocyanate group, an oxirane ring, and an acid anhydride, can be copolymerized as needed.

  In addition, (a) the weight average molecular weight of the binder polymer (measured by gel permeation chromatography and converted to standard polystyrene) was heat resistance, heat meltability, coatability, and a microlens array photosensitive element described later. From the viewpoints of film properties (characteristics for maintaining a film-like form), solubility in a solvent, solubility in a developing solution in the development step, and the like, it is preferably 1000 to 300000, 5000 to 150,000. More preferably.

  Further, (a) the binder polymer preferably has an acid value so that it can be developed with various known developing solutions. 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 is facilitated, and when it is 260 mgKOH / g or less, the developer resistance (the property that the portion that becomes a pattern without being removed by development is not affected by the developer) is obtained. It will be enough. 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, development is easier, and when the acid value is 260 mgKOH / g or less, the developer resistance is more sufficient.

  (B) As a photopolymerizable unsaturated compound having an ethylenically unsaturated group, for example, a compound obtained by reacting a polyhydric alcohol and an α, β-unsaturated carboxylic acid, 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, a urethane monomer, nonylphenyldioxylene (meth) acrylate, γ- Chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxypropyl-β ′-(meta ) Acryloyloxyethyl-o-phthalate, (meth) acrylic acid alkyl ester and the like. In the present specification, (meth) acryloxy means “acryloxy and / or methacryloxy”, and (meth) acrylate means “acrylate and / or methacrylate”, and these similar phrases also have the same meaning. is there.

  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, 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.

  (C) 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, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (“Irgacure-369”, BASF Japan ( Aromatic ketones such as 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one ("Irgacure-907", trade name of BASF Japan 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-phenanthra Quinones such as quinone, 2-methyl-1,4-naphthoquinone and 2,3-dimethylanthraquinone; benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether and benzoin phenyl ether; benzoins such as benzoin, methyl benzoin and ethyl benzoin Compound; benzyl derivative such as benzyldimethyl ketal; 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4, 2,4,5-triarylimidazole dimers such as 5-diphenylimidazole dimer; acridine derivatives such as 9-phenylacridine, 1,7-bis (9,9′-acridinyl) heptane; N-phenylglycine , N-phenylglycine derivatives, coumarin compounds and the like.

  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 the present embodiment, 2,4,5-triarylimidazole dimer is preferable from the viewpoint of adhesion to the substrate and sensitivity. Furthermore, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one is more preferable from the viewpoint of visible light transmittance.

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

  In this embodiment, the blending ratio of the (a) binder polymer is preferably 20 to 90 parts by mass, and preferably 30 to 85 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). It is more preferable to set it as 35-80 mass parts, and 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, the heat melting property, and the film property are improved, and when it is 90 parts by mass or less, the photocurability and the heat resistance are sufficient.

  In addition, the blending ratio of the photopolymerizable unsaturated compound having (b) an ethylenically unsaturated group is preferably 10 to 80 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). It is more preferably 15 to 70 parts by mass, particularly preferably 20 to 65 parts by mass, and particularly preferably 25 to 60 parts by mass. When the blending ratio is 10 parts by mass or more, photocurability and heat resistance are improved, and when it is 80 parts by mass or less, the coating property, the heat melting property, and the film property are sufficient.

  Moreover, it is preferable that the mixture ratio of (c) photoinitiator shall be 0.05-20 mass parts with respect to 100 mass parts of total amounts of (a) and (b) component, and 0.1-15 mass parts More preferably, the content is 0.15 to 10 parts by mass. When the blending ratio is 0.05 parts by mass or more, photocuring is sufficient, and when it is 20 parts by mass or less, absorption of actinic rays on the actinic ray-irradiated surface of the photosensitive layer is suppressed at the time of exposure. Photocuring is sufficient.

  In the photosensitive resin composition in the present embodiment, if necessary, an adhesion imparting agent such as a silane coupling agent, a leveling agent, a plasticizer, a filler, an antifoaming agent, a flame retardant, a stabilizer, and an antioxidant. , Fragrance, thermal crosslinking agent, 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.

(Transparent material)
The material of the transparent member is not particularly limited as long as it is transparent to the optical signal, but from the viewpoint of the production method described later, it is a cured product of the photosensitive resin composition or a cured product of the thermosetting resin composition. From the viewpoint that it can be formed together with the lens member, a cured product of the photosensitive resin composition is more preferable. This photosensitive resin composition is the same as that of the lens member.
The front end surface of the transparent member may be the same as the surface of the substrate, and may be drawn in more than the surface of the substrate, but it protrudes from the viewpoint of shortening the optical path between the object for optical communication. Preferably it is.

<Method for manufacturing substrate with lens>
The manufacturing method of the board | substrate with a lens of this invention includes the following processes 1-4.
Step 1: The photosensitive resin composition for a lens member is laminated on one surface of the substrate and filled in the through hole, and the transparent resin composition is laminated on the other surface of the substrate and in the through hole. Step of filling Step 2: Irradiating actinic rays from the other surface side of the substrate to expose and cure the photosensitive resin composition for the lens member, and photocuring or thermosetting the transparent resin composition Step 3: Step of developing and removing an uncured portion of the photosensitive resin composition for a lens member to form a columnar transparent member extending from the inside of the through hole to the outside of one surface of the substrate. 4: The step of heating the columnar transparent member and dripping the tip portion of the columnar transparent member that protrudes from the substrate to form a convex lens surface. Is irradiated to the photosensitive resin composition for a lens member through the transparent resin composition in the through hole, so that the photosensitive resin composition for the lens member can be reliably photocured regardless of the type of the substrate. . Moreover, since actinic light is irradiated toward the front end part side from the base end part side of the columnar transparent member, the base end part side can be hardened more than the front end part side of the columnar transparent member. Therefore, the tip end portion is more easily dripped than the base end portion during heating, and the convex lens surface can be accurately formed on the tip end portion.
Next, the lens-equipped substrate and the manufacturing method thereof according to the present invention will be specifically described.

[Lens Substrate and Method for Producing the Same (First Embodiment)]
A substrate with lens 1 according to a first embodiment and a method for manufacturing the same will be described with reference to the drawings.
1A is a plan view of the lens-equipped substrate 1 according to the first embodiment, FIG. 1B is a cross-sectional view taken along line BB in FIG. 1A, and FIG. It is a front view of the lens member of 1 (a). FIG. 2 is a cross-sectional view showing an example of a method for manufacturing the lens-attached substrate of FIG.

<Substrate with lens 1>
This substrate 1 with a lens extends from the inside of the through hole 2a to the outside of one surface of the substrate 2 (the upper surface of FIG. 1B) through the through hole 2a (see FIG. 2A). The lens member 4 is present, and the transparent member 3 is present on the other surface (the lower surface in FIG. 1B) of the substrate 2 with respect to the lens member 4 in the through hole 2a.
The lens member 4 has a base end face 4y that is in contact with the base end face of the transparent member 3 inside the through hole 2a, and a tip end face that protrudes from the through hole 2a to form a convex lens surface 4x that is convexly curved. It has a shape.
On the other hand, the transparent member 3 has a base end surface in contact with the base end surface 4y of the lens member 4 inside the through hole 2a. In the present embodiment, the distal end portion of the transparent member 3 is a flange that protrudes from the through hole 2 a and protrudes along the other surface (lower surface) of the substrate 2. That is, the front end surface of the transparent member 3 is a flat surface that protrudes from the other surface (lower surface) of the substrate 2. By this collar part, the intensity | strength with respect to the pressing force of the substrate thickness direction of the transparent member 3 becomes high.

The lens-equipped substrate 1 configured as described above is configured such that, for example, optical members such as a light emitting element, a light receiving element, and an optical waveguide are disposed at a position facing the lens member 4 and a position facing the transparent member 3. Provided for communication.
For example, an optical signal emitted from a light emitting element present at a position facing the transparent member 3 enters from the base end surface of the transparent member 3. At this time, since the base end surface of the transparent member 3 is a flat surface, light scattering is suppressed. The incident optical signal passes through the transparent member 3 and the lens member 4, and is then collected by the convex lens surface 4x and incident on a light receiving element that is located at a position facing the convex lens surface 4x, thereby reducing light loss. Optical communication.

<Method for manufacturing substrate 1 with lens>
The lens-equipped substrate 1 can be preferably manufactured by the following manufacturing method.
(Step 1a)
In step 1a, as shown in FIGS. 2A and 2B, the lens member photosensitive resin composition 4a is laminated on one surface (upper surface) of the substrate 2 and filled in the through hole 2a. The transparent resin composition (preferably a photosensitive resin composition) 3a is laminated on the other surface (lower surface) of the substrate and filled into the through hole 2a. In the present embodiment, a material that shields actinic rays is used for the substrate 2.
The method for laminating these photosensitive resin compositions 4a and 3a on the substrate 2 is not particularly limited, and when the photosensitive resin compositions 4a and 3a are liquid, they may be applied to the substrate 2 by a conventional method. When the photosensitive resin compositions 4a and 3a are 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. The order of lamination is not particularly limited, and (a) after the photosensitive resin composition 4a is laminated on one surface of the substrate 2, the photosensitive resin composition 3a may be laminated on the other surface of the substrate 2. (B) after the photosensitive resin composition 3a is laminated on the other surface of the substrate 2, the photosensitive resin composition 4a may be laminated on one surface of the substrate 2, or (c) the photosensitive resin. The compositions 4a and 3a may be laminated simultaneously.
In the case of (a), the boundary surface between the photosensitive resin compositions 4a and 3a is near the other surface of the substrate 2, in the case of (b), near the one surface of the substrate 2, and in the case of (c). Is near the center of the substrate 2 in the thickness direction. In the case of (c), it is more preferable because it is easy to ensure the flatness of the boundary surface between the photosensitive resin compositions 4a and 3a.

(Step 2a)
In step 2a, as shown in FIG. 2B, a mask 10 having an opening 10a larger than the through hole 2a at a position facing the through hole 2a is disposed on the other surface (lower surface) side of the substrate 2. The photosensitive resin compositions 4a and 3a are exposed and cured by irradiating actinic rays through the mask 10 from the other surface (lower surface) side of the substrate 2.

(Step 3a)
In step 3, the uncured portions of the photosensitive resin compositions 4a and 3a are developed and removed to form the transparent member 3 and the columnar transparent member 4b (FIG. 2 (c)). At this time, when the substrate 2 is made of a light shielding material, the width of the columnar transparent member 4b is the same as the width of the through hole 2a as shown in FIG. On the other hand, when the substrate 2 is made of a non-light-shielding material, the width of the portion of the columnar transparent member 4b existing in the through hole 2a is the same as the width of the through hole 2a, and the portion protruding from the through hole 2a Is the same as the width of the opening 10a of the mask 10 (not shown).

(Step 4a)
In step 4a, the columnar transparent member 4b is heated, and the tip of the columnar transparent member 4b protruding from the substrate 2 is dripped to form the convex lens surface 4x. In this way, the lens member 4 is formed.

[Lens Substrate and Method for Producing the Same (Second Embodiment)]
Next, a lens-equipped substrate 1A according to a second embodiment and a manufacturing method thereof will be described with reference to the drawings. FIG. 3 is a cross-sectional view of the lens-equipped substrate 1A according to the second embodiment.
The substrate with lens 1A is the same as the substrate with lens 1 of FIGS. 1 and 2 except that the front end surface of the transparent member 3A is a convex lens surface, and the same reference numerals denote the same parts.
This lens-equipped substrate 1A can be formed by heating the tip end surface of the transparent member and letting it drip in step 4a.
According to this substrate 1A with a lens, it can be condensed by the upper and lower lenses.

[Lens with substrate and manufacturing method thereof (third embodiment)]
4A is a perspective view of a lens-equipped substrate (lens-attached electrical wiring substrate) 1B according to the third embodiment, and FIG. 4B is a cross-sectional view taken along line BB in FIG. 4A. is there. 5A is a plan view of the lens-equipped substrate 1B as viewed from above in FIG. 4A, and FIG. 5B is a plan view of the lens-equipped substrate 1B as viewed from below in FIG. 4A.
This lens-equipped substrate 1B is the same as the lens-equipped substrate 1 of FIGS. 1 and 2 except that it has electrical wiring and optical elements, and the same reference numerals indicate the same parts.
That is, in this lens-equipped substrate 1B, wirings 7a, 7b, and 7c are provided on the upper surface of the substrate 2, and wirings 5a, 5b, and 5c are provided on the lower surface of the substrate 2. Further, the wirings 7 a and 5 a are connected by the plated through hole 6 a that penetrates the substrate 2, and the wirings 7 b and 5 b are connected by the plated through hole 6 b that penetrates the substrate 2. The light emitting element (optical element) 11 is connected to the wirings 5a and 5c via the bump 11a, and the light receiving element (optical element) 12 is connected to the wirings 5b and 5c via the bump 12a.

This lens-equipped substrate 1B uses an electric wiring substrate having the wirings 5a to 5c and 7a to 7c and the plated through holes 6a and 6b on the substrate 2 instead of the substrate 2 in the step 1a, and after the step 4a. It can be manufactured by installing the optical members 11 and 12 on the wirings 5a to 5c via the bumps 11a and 12a.
According to this lens-equipped substrate 1B, the functions of both optical communication and telecommunication can be given to one substrate.

[Lens Substrate and Manufacturing Method Therefor (Fourth Embodiment)]
FIG. 6 is a cross-sectional view of a lens-equipped substrate 1C according to the fourth embodiment.
The substrate with lens 1C forms a through hole 2b together with the through hole 2a when drilling the substrate, and the uncured photosensitive resin compositions 4a and 3a existing in the through hole 2b at the time of step 3a. It can be suitably produced by developing and removing the portion, and can also be suitably produced by forming the through hole 2b in the substrate 2 with a drill or a laser after the step 4a.
According to the substrate with lens 1C, although not shown, the optical fiber connector can be fixed with high positional accuracy and coupling efficiency by inserting the coupling pin provided in the optical fiber connector into the through hole 2b. it can.

[Lens Substrate and Manufacturing Method Thereof (Fifth Embodiment)]
FIG. 7 is a cross-sectional view of a lens-equipped substrate (lens-attached electrical wiring substrate) 1D (1E) according to the fifth embodiment.
In this lens-equipped substrate 1D (1E), wirings 7a and 7b provided on the upper surface of the substrate 2 and wirings 5a and 5b provided on the lower surface of the substrate 2 are connected by plated through holes 6a and 6b. The optical element 11 (12) is connected to the wirings 5a and 5b via bumps.
This lens-equipped substrate 1D (1E) can be manufactured in the same manner as the lens-equipped substrate 1B shown in FIGS.
Also with this lens-equipped substrate 1D (1E), it is possible to impart both optical communication and electrical communication functions to one substrate.

[Lens Substrate and Method for Manufacturing the Same (Sixth Embodiment)]
Reference numeral 1F in FIG. 9C is a cross-sectional view of the lens-equipped substrate 1F according to the sixth embodiment.
This lens-equipped substrate 1F is obtained by providing a lower clad layer 22 that occupies the lower side of the through hole and covers the lower surface side of the substrate in place of the transparent member 3 in the lens-equipped substrate 1 of FIGS. It is.
The lens-equipped substrate 1F will be described in more detail in the description of the optical waveguide with lens described later, but can be suitably used as a part of the optical waveguide with lens.

[Optical waveguide with lens and manufacturing method thereof]
(Optical waveguide with lens)
An optical waveguide with a lens according to the present invention includes the above-described substrate with a lens according to the present invention, a lower clad layer on the surface of the other end side of the through hole in the substrate, and a core present on the lower clad layer. A layer, an upper clad layer present on the core layer, and a mirror present at a position facing the lens in the core layer. Here, it is preferable that a part of the lower cladding layer constitutes the transparent member.
According to the optical waveguide with a lens of the present invention, the optical signal propagated in the core is converted by the mirror, and then condensed and emitted by the convex lens surface of the lens member. In addition, since the optical signal incident on the convex lens surface from the outside of the optical waveguide with lens is condensed on the convex lens surface, the optical path is changed by the mirror and propagated in the core, so that there is little optical loss.

(Manufacturing method of optical waveguide with lens)
Said optical waveguide with a lens can be suitably manufactured with the manufacturing method containing following process AF.
Step A: Filling the through-hole with the photosensitive resin composition for a lens from one side of the through-hole of the substrate having a through-hole and having a light-shielding property, and the other side of the through-hole Step B: forming a transparent resin composition in the through hole and on the other surface Step B: Exposing the photosensitive resin composition for a lens by irradiating actinic rays from the other surface side of the substrate Step of forming the lower cladding layer by photocuring or thermosetting the transparent resin composition while being cured Step C: developing and removing uncured portions of the photosensitive resin composition for lenses, and the inside of the through hole Forming a columnar transparent member extending over the outside of one surface of the substrate from step D: heating the columnar transparent member and projecting from the substrate out of the columnar transparent member A step of dripping the tip portion to form a convex lens surface Step E: forming a core layer on the surface of the lower clad layer and forming an upper clad layer on the surface of the core layer Step F: the step of forming the core layer Step of Forming Mirror at Position Opposed to Through Hole Next, each member of the optical waveguide with lens and a manufacturing method thereof will be described.

(Substrate with lens)
The substrate with lens is as described above.

(Lower cladding layer and upper cladding layer)
As a material for the lower cladding layer and the upper cladding layer, a resin composition for forming a cladding layer or a resin film for forming a cladding layer can be used.
The resin composition for forming a clad layer used in the present invention is not particularly limited as long as it is a resin composition that has a lower refractive index than the core and is cured by light or heat, and a thermosetting resin composition or a photosensitive resin composition. A thing can be used conveniently. The resin composition used for the resin for forming the clad layer may have the same or different components contained in the resin composition in the lower clad layer and the upper clad layer, and the refractive index of the resin composition is the same. Or different.
In the present invention, the method for forming the clad layer is not particularly limited. For example, the clad layer may be formed by coating the clad layer forming resin composition or laminating the clad layer forming resin film.
In the case of application, the method is not limited, and the clad layer forming resin composition may be applied by a conventional method.
The clad layer-forming resin film used for laminating can be easily produced by, for example, dissolving the clad layer-forming resin composition in a solvent, applying it to a carrier film, and removing the solvent.
The thickness of the lower cladding layer and the upper cladding layer 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 and the upper cladding layer is more preferably in the range of 10 to 100 μm.

(Core layer)
As the core layer, a core layer forming resin or a core layer forming resin film can be used.
The core layer forming resin is preferably designed to have a higher refractive index than the lower clad layer and the upper clad layer, and can form a core pattern with actinic rays. The method of forming the core layer before patterning is not limited, and examples thereof include a method of applying the core layer forming resin composition by a conventional method.
The thickness of the resin film for forming the core layer is not particularly limited, and the thickness of the core layer after drying is usually adjusted to be 10 to 100 μm. When the thickness of the core 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.

[Optical Waveguide with Lens and Manufacturing Method Therefor (Seventh Embodiment)]
Next, the optical waveguide with lens 20 and the manufacturing method thereof according to the present invention will be described in detail with reference to the drawings.
8A is a perspective view of the optical waveguide 20 with a lens, FIG. 8B is a plan view of the optical waveguide 20 with a lens, and FIG. 8C is a cross-sectional view of FIG. 8A. FIG. 9 is a cross-sectional view illustrating a method of manufacturing the optical waveguide with lens 20.

(Optical waveguide with lens 20)
The optical waveguide with lens 20 includes a substrate with lens 1F (see FIG. 9C) and an optical waveguide member with mirror 29 (see FIG. 9D).
The substrate with lens 1F includes a substrate 21 having a through hole, a lens member 26 extending from the inside of the through hole to the outside (upper side) of one surface of the substrate 21 (the upper surface of FIG. 9C), And a lower clad layer 22 existing on the other surface (lower surface) of the substrate 21. A part of the lower clad layer 22 protrudes to the other surface (lower surface) side of the substrate 21 from the lens member 26 inside the through hole to constitute a transparent member.
The lens member 26 has a base end surface (lower surface) in contact with a transparent member (protrusion portion of the lower clad layer) inside the through hole, and a shape in which the front end surface is a convex lens surface protruding from the through hole. have.
The optical waveguide member 29 with a mirror includes the lower cladding layer 22, a core layer 23 existing on the lower cladding layer 22, and an upper cladding layer 24 existing on the core layer 23. Therefore, the lower clad layer 22 constitutes a part of the lens-equipped substrate 1F and a part of the optical waveguide member 29 with a mirror. A groove 25 having an inverted V-shaped cross section is formed from the surface of the upper cladding layer 24 to at least a part of the core layer 23 toward the core layer 23 side, and a side surface of the groove 25 serves as a mirror 25a. . As shown in FIG. 8C, the mirror 25a is present at a position facing the lens member 26.
According to the optical waveguide with lens 20, the optical signal propagated in the core layer 23 is converted by the mirror 25 a and then condensed and emitted by the convex lens surface of the lens member 26. In addition, since the optical signal incident on the convex lens surface of the lens member 26 from the outside of the optical waveguide with lens 20 is collected on the convex lens surface, the optical path is changed by the mirror and propagated in the core layer 23, so that the optical loss is lost. Less is.

(Method for manufacturing optical waveguide 20 with lens)
Said optical waveguide 20 with a lens can be suitably manufactured with the manufacturing method containing following process AF.

<< Process A >>
In step A, the photosensitive resin composition 26a for the lens member is formed in one surface (upper surface) of the through hole and in the through hole of the substrate 21 having the through hole and having light shielding properties, A transparent resin composition (photosensitive resin composition) 22a is formed on the other surface and in the through hole.
There is no restriction | limiting in particular about the method of laminating | stacking the photosensitive resin composition 26a for lens members, and the transparent resin composition (photosensitive resin composition) 22a on the board | substrate 21, The photosensitive resin composition 26a for lens members and a transparent resin composition When the product (photosensitive resin composition) 22a is liquid, it may be applied to the substrate 21 by a conventional method. When the lens member photosensitive resin composition 26a and the transparent resin composition (photosensitive resin composition) 22a are 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. The order of lamination is not particularly limited. (A) After forming the photosensitive resin composition 26a for lens member on the surface of the substrate 21, the transparent resin composition (photosensitive resin composition) 22a is formed on the back surface of the substrate 21. (B) The transparent resin composition (photosensitive resin composition) 22a is laminated on the back surface of the substrate 1, and then the lens member photosensitive resin composition 26a is laminated on the surface of the substrate 21. Alternatively, (c) the lens member photosensitive resin composition 26a and the transparent resin composition (photosensitive resin composition) 22a may be laminated simultaneously.
The boundary surface between the lens member photosensitive resin composition 26a and the transparent resin composition (photosensitive resin composition) 22a is in the vicinity of the back surface of the substrate 21 in the case of (a), and the substrate in the case of (b). 21 near the surface, and in the case of (c), near the center of the substrate 21 in the thickness direction. In the case of (c), since the flatness of each resin surface of the photosensitive resin composition 26a for lens members and the transparent resin composition (photosensitive resin composition) 22a is easy to ensure, it is especially preferable.

(Process B)
In step B, the lens member photosensitive resin composition 26a is exposed and cured by irradiating actinic rays from the other surface side of the substrate 21, and the transparent resin composition 22a is photocured. The lower cladding layer 22 is formed. Here, by using the base material 21 as a light-shielding material, only a region corresponding to a columnar transparent member 26b described later is cured by exposure.

(Process C)
In Step C, the uncured portion of the photosensitive resin composition 26a for lens member is developed and removed to form a columnar transparent member 26b extending from the inside of the through hole to the outside of one surface of the substrate 21.
The method for forming the columnar transparent member 26b may be to remove the uncured resin portion by etching, or to etch using a developer that can remove the uncured resin portion.

(Process D)
In step D, the columnar transparent member 26b is heated, and the tip of the columnar transparent member 26b protruding from the substrate 21 is dripped to form a convex lens surface. This process is the same as in the case of the lens-attached substrate described above.

(Process E)
In step E, a core layer 23 is formed on the surface of the lower cladding layer 22, and an upper cladding layer 24 is formed on the surface of the core layer 23.
The method for forming each layer is not particularly limited, and a liquid clad layer forming resin composition or a core layer forming resin composition may be applied by spin coating or the like, or a film-shaped clad layer forming resin composition. Or you may laminate the resin composition for core layer formation by methods, such as a roll laminator, a vacuum laminator, a press, a vacuum press.

(Process F)
In Step F, a mirror is formed in the core layer 23 at a position facing the through hole.
As a method for forming the mirror, a known method can be applied. For example, it can be formed by cutting the core layer 23 using a dicing saw or the like from the upper clad layer 24 forming surface side. The mirror to be formed is preferably 45 °.
Moreover, it is good also as a mirror part provided with a reflective metal layer by vapor-depositing metals, such as gold | metal | money, using a vapor deposition apparatus for a mirror part. This process F may be performed in the process E after laminating | stacking the core layer 23 of the above-mentioned process E. FIG.

[Optical Waveguide with Lens and Manufacturing Method Thereof (Eighth Embodiment)]
10A is a perspective view of the optical waveguide 30 with a lens, FIG. 10B is a plan view of the optical waveguide 30 with a lens, and FIG. 10C is a cross-sectional view taken along the line CC in FIG. It is.
The optical waveguide with lens 30 is the optical waveguide with lens of FIGS. 8 and 9, in which wirings 5a to 5c are provided on the upper surface of the substrate 21, and the light emitting element 11 and the light receiving element 12 are installed via bumps. .
This optical waveguide with lens 30 uses an electrical wiring board in which wirings 7a to 7d are formed in place of the substrate 21 in the optical waveguide with lens 20 of FIGS. 8 and 9, and the optical element 11 and 12 may be installed.

[Optical Waveguide with Lens and Manufacturing Method Thereof (Ninth Embodiment)]
The optical waveguide with lens 40 in FIG. 11 is obtained by installing the lens-equipped substrate 1D (1E) in FIG. 7 instead of the optical elements 11 and 12 in the optical waveguide 30 with lens in FIG.

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

(Measurement of weight average molecular weight)
2. As a result of measuring the weight average molecular weight (standard polystyrene conversion) of (A-1) using GPC (“SD-8022”, “DP-8020”, and “RI-8020” manufactured by Tosoh Corporation). It was 9 × 10 ⁴ . The column used was “Gelpack GL-A150-S” and “Gelpack GL-A160-S” manufactured by Hitachi Chemical Co., Ltd.
(Measurement of acid value)
As a result of measuring the acid value of A-1, it was 79 mgKOH / g. In addition, the acid value was computed from the amount of 0.1 mol / L potassium hydroxide aqueous solution required for neutralizing A-1 solution. At this time, the point at which the phenolphthalein added as an indicator changed color from colorless to pink was defined as the neutralization point.

<Preparation of resin varnish for forming clad layer>
(A) As the base polymer, 84 parts by mass (solid content: 45% by mass) of the A-1 solution (solid content: 45% by mass), (B) Urethane (meth) acrylate having a polyester skeleton as the photocuring component (Shin Nakamura) 33 parts by mass of “U-200AX” manufactured by Chemical Industry Co., Ltd., and 15 parts by mass of urethane (meth) acrylate having a polypropylene glycol skeleton (“UA-4200” manufactured by Shin-Nakamura Chemical Co., Ltd.), (C) heat As a curing component, 20 parts by mass of a polyfunctional block isocyanate solution (solid content: 75% by mass) obtained by protecting an isocyanurate type trimer of hexamethylene diisocyanate with methyl ethyl ketone oxime (“Sumijour BL3175” manufactured by Sumika Bayer Urethane Co., Ltd.) (Solid content 15 parts by mass), (D) As a photopolymerization initiator, 1- [4- (2-hydroxy ester) 1 part by mass of xy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (“Irgacure 2959” manufactured by BASF Japan Ltd.), bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide 1 part by mass (“Irgacure 819” manufactured by BASF Japan 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 a resin film for forming a cladding 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.
The thickness of the clad layer forming resin film can be arbitrarily adjusted by adjusting the gap of the coating machine, and is described in the examples. The film thickness of the upper clad layer forming resin film described in the examples is the film thickness after coating.

[Production of core layer forming resin film and lens member 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) As a photopolymerization initiator, 1 part by mass of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (trade name: Irgacure 819, manufactured by BASF Japan Ltd.), and 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (trade name: Irgacure 2959, BASF Di) Pan Ltd.) 1 part by weight, except for using 40 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent was prepared a core layer forming resin varnish B in the same manner and conditions as the above Production Example. Thereafter, pressure filtration and degassing under reduced pressure were performed under the same method and conditions as in the above production example.
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 B obtained above is used. Apply and dry in the same manner as above, and then attach a release PET film (trade name: PUREX A31, Teijin DuPont Films, Inc., thickness: 25 μm) as a protective film so that the release surface is on the resin side A resin film for forming a core layer was obtained.
The lens member forming resin film was also obtained by performing the same operation as the core layer forming resin film.
At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine. In this example, the thickness of the resin film for forming the core layer and the resin film for forming the lens member was used. Described in the examples. The film thickness of the core layer forming resin film described in the examples is the film thickness after coating.

[Preparation of substrate 2 with through hole]
A 150 mm × 150 mm polyimide film (made by Ube Nitto Kasei Co., Ltd., trade name: Upilex RN, thickness: 25 μm) as a substrate 2 was drilled into two through holes with a diameter of 150 μm (through-hole center distance: 100 mm) ) To obtain a substrate with through holes.

[Formation of substrate 1 with lens]
The resin film for forming a lens member having a thickness of 25 μm and the resin film for forming a cladding layer having a thickness of 25 μm obtained above were disposed on both sides of the substrate obtained above after peeling off the protective film. Using a vacuum pressurization type laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.), after vacuuming to 500 Pa or less, thermocompression bonding was performed under conditions of a pressure of 0.4 MPa, a temperature of 110 ° C., and a pressurization time of 30 seconds. By laminating, a photosensitive resin composition 4a for forming a lens member and a transparent resin composition 3a were obtained.

Next, a mask 10 having an opening 10a is applied to the lower side of the substrate, and ultraviolet rays (wavelength 365 nm) are applied at 300 mJ / cm ² from below the substrate using an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). Irradiation was performed, and the photosensitive resin composition 4a for forming a lens member and the transparent resin composition 3a were photocured.
Thereafter, the support films on both sides were peeled off, and the resin uncured portion was etched using a developer (1% aqueous potassium carbonate solution), and then washed with water to form the columnar transparent member 4b and the transparent member 3. Thereafter, the lens member 4 and the transparent member 3 were formed by heating and drying at 170 ° C. for 1 hour and curing.

[Evaluation]
As a result of observing the lens member 4, the diameter was 151 μm, the cross-sectional shape was a height of 25 μm, and the curvature radius was 125 μm. The cross-sectional shape on the transparent member 3 side was 25 μm high and flat. An optical signal of 850 nm is incident from the transparent member 3 side using a GI50 multimode optical fiber for the incident portion, and the GI62.5 multimode optical fiber installed on the lens member 4 side is used for the light receiving portion. When the distance was 100 μm, the light propagation loss was 0.45 dB. The distance between the optical fiber tips was 200 μm, which was 0.55 dB.

Example 2
According to the following procedure, the optical waveguide with lens 20 shown in FIGS. 8 and 9 (however, the number of the lens members 26 is two) was prepared and evaluated.
[Preparation of Cladding Layer Forming Resin Film and Core Layer Forming Resin Film]
These were produced in the same manner as in Example 1.
[Preparation of substrate 21 with through hole]
The substrate 21 with a through hole was the same as the substrate 2 with a through hole.

[Formation of substrate with lens]
The 25 μm-thick lens member-forming resin film and the 25 μm-thick clad layer-forming resin film obtained above were respectively disposed on both sides of the substrate 21 obtained above after peeling off the protective film. Using a vacuum pressurization type laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.), after vacuuming to 500 Pa or less, thermocompression bonding was performed under conditions of a pressure of 0.4 MPa, a temperature of 110 ° C., and a pressurization time of 30 seconds. The photosensitive resin composition 26a for forming a lens member and the transparent resin composition 22a were obtained by laminating.
Next, ultraviolet rays (wavelength 365 nm) are irradiated from below the substrate with 300 mJ / cm ² from below the substrate 21 without using the mask 10 with an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). The lens member-forming photosensitive resin composition 26a and the transparent resin composition 22a were photocured.
Thereafter, the support films on both sides were peeled off, and the resin uncured portion was etched using a developer (1% aqueous potassium carbonate solution), and then washed with water to form the columnar transparent member 26b and the lower cladding layer 22. Thereafter, the lens member 26 and the lower clad layer 22 were formed by heating and drying at 170 ° C. for 1 hour and curing.

[Formation of optical waveguide with lens]
On the lower clad layer 22 obtained as described above, the resin film for core layer formation having a thickness of 50 μm obtained above is disposed after the protective film is peeled off, and a roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd., HLM). -1500) under the conditions of pressure 0.4 MPa, temperature 50 ° C., laminating speed 0.2 m / min, and then using the above-mentioned vacuum pressure laminator (MVLP-500, manufactured by Meiki Seisakusho) After vacuuming to 500 Pa or less, 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.

Subsequently, a negative photomask having an opening with a core pattern width of 50 μm is aligned so that the core pattern is formed on the lens member 26, and the support film side is used by using the ultraviolet exposure machine. Then, ultraviolet rays (wavelength 365 nm) were irradiated at 0.8 J / cm ² , and then after exposure at 80 ° C. for 5 minutes, heating was performed. Thereafter, the PET film as the support film was peeled off, and the core pattern was etched using a developer (propylene glycol monomethyl ether acetate / N, N-dimethylacetamide = 8/2, mass ratio). Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (s), and the core layer 23 was formed.

From the obtained core layer 23, the 55 μm-thick clad layer-forming resin film obtained above is disposed after the protective film is peeled off, and a vacuum pressure laminator (manufactured by Meiki Seisakusho Co., Ltd., 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. Subsequently, using the above ultraviolet exposure machine, ultraviolet (wavelength 365nm) 3.0J / cm ² was irradiated from the support film side of the resin film for forming a cladding layer, after peeling the support film, 1 hour dried by heating at 170 ° C. And cured to form an optical waveguide member.

[Formation of mirror part]
A 45 ° mirror 25a was formed immediately above the lens member 26 using a dicing saw (DAC552, manufactured by Disco Corporation) from the upper clad layer 24 side of the obtained optical waveguide member. This obtained the optical waveguide 20 with a lens. The distance between the mirrors 25a was 10 cm.

[Evaluation]
As a result of observing the lens member 4, the diameter was 151 μm, the cross-sectional shape was a height of 25 μm, and the curvature radius was 125 μm. The cross-sectional shape on the transparent member 3 side was 25 μm high and flat. An optical signal of 850 nm is incident from one lens member 26 side using a multimode optical fiber of GI50 for the incident portion, and GI62.5 multimode light is installed on the other lens member 26 side for the light receiving portion. When the distance between the lens member 26 and the optical fiber tip was 30 μm, the optical propagation loss was 3.55 dB. When the distance between the lens member 26 and the tip of the optical fiber was 100 μm, it was 3.64 dB.

Example 3
In Example 1, when forming a through hole in a board | substrate, in addition to the through hole 2a for formation of a lens member, two through holes 2b for fitting pin holes are installed (see FIG. 6). By this method, a substrate with a lens with a fitting pin hole was produced. As a result of evaluation, the optical propagation loss value was the same as in Example 1.

Example 4
In Example 1, after forming a through hole in a polyimide film with a single-sided copper foil (polyimide; Upilex VT (25 μm) manufactured by Ube Nitto Kasei, copper foil; NA-DFF (12 μm) manufactured by Mitsui Metals), the copper film A substrate with a lens was produced in the same manner except that the electric wiring was formed by subtractive foil. When evaluated in the same manner, it was the same optical propagation loss value as in Example 1.

Example 5
A substrate with a lens was produced in the same manner as in Example 1 except that a lens forming resin film was used instead of the core layer forming resin film as the material of the transparent member 4. As a result of observing the lens member 4, the cross-sectional shape of the lens far from the exposure light source was 25 μm in height and 125 μm in radius of curvature. The cross-sectional shape of the lens near the exposure light source had a height of 25 μm and a radius of curvature of 300 μm.

DESCRIPTION OF SYMBOLS 1 Substrate with lens 2 Substrate 2a Through hole 3 Transparent member 4 Lens member 20 Optical waveguide with lens 21 Substrate 22 Lower clad layer 23 Core layer 24 Upper clad layer 25 Groove 25a Mirror

Claims (13)

A substrate having a through hole;
A lens member extending from the inside of the through hole to the outside of one surface of the substrate;
A transparent member present on the other surface side of the substrate than the lens member in the through hole; and
A substrate with a lens,
The base end surface of the lens and the base end surface of the transparent member are in contact with each other inside the through hole,
The front surface of the lens is a convex lens surface that protrudes from the through hole and is convexly curved .
The said transparent member is a board | substrate with a lens which has a collar part which protruded from the said through hole and protruded along the other surface of the said board | substrate on the opposite side to the base end surface of the said transparent member . The substrate with a lens according to claim 1, wherein a base end surface of the transparent member is a plane parallel to the surface of the substrate. The board | substrate with a lens of Claim 1 or 2 whose said board | substrate is an electrical wiring board which has an electrical wiring. The lens-attached substrate according to claim 1 , wherein a front end surface of the transparent member is a non-lens surface parallel to the surface of the substrate. The distal end surface of the transparent member has a convex surface that protrudes from the through hole, the lens-attached substrate according to any one of claims 1 to 3. The manufacturing method of the board | substrate with a lens of any one of Claim 1 to 5 including the following processes 1-4.
Step 1: The photosensitive resin composition for a lens member is laminated on one surface of the substrate and filled in the through hole, and the transparent resin composition is laminated on the other surface of the substrate and in the through hole. Step of filling Step 2: Irradiating actinic rays from the other surface side of the substrate to expose and cure the photosensitive resin composition for the lens member, and photocuring or thermosetting the transparent resin composition Step 3: Step of developing and removing an uncured portion of the photosensitive resin composition for a lens member to form a columnar transparent member extending from the inside of the through hole to the outside of one surface of the substrate. 4: Heating the columnar transparent member to form a convex lens surface by dripping the tip of the columnar transparent member protruding from the substrate. In the step 2, by placing a mask having an opening at a position facing the through hole on the other surface side of the substrate and irradiating actinic rays through the mask from the other surface side, The manufacturing method of the board | substrate with a lens of Claim 6 which exposes and cures the said photosensitive resin composition for lens members. The substrate has light shielding properties;
The said process 2 WHEREIN: By irradiating actinic light from the other surface side of the said board | substrate, the part facing the said through hole among the said photosensitive resin compositions for lens members is exposed and hardened | cured to Claim 6 . The manufacturing method of the board | substrate with a lens of description. The method for manufacturing a substrate with a lens according to claim 6 , wherein the transparent resin composition is a photosensitive resin composition. A substrate with a lens according to any one of claims 1 to 5 ,
A lower clad layer present on the surface of the substrate on the other end side of the through hole;
A core layer present on the lower cladding layer;
An upper cladding layer present on the core layer;
The optical waveguide with a lens which has a mirror which exists in the position which opposes the said lens among the said core layers. The optical waveguide with a lens according to claim 10 , wherein a part of the lower cladding layer constitutes the transparent member. The manufacturing method of the optical waveguide with a lens which forms an optical waveguide member in said other surface of the board | substrate with a lens of any one of Claim 1 to 5 . The manufacturing method of the optical waveguide with a lens of Claim 11 containing the following process AF.
Step A: Filling the through-hole with the photosensitive resin composition for a lens from one side of the through-hole of the substrate having a through-hole and having a light-shielding property, and the other side of the through-hole Step B: forming a transparent resin composition in the through hole and on the other surface Step B: Exposing the photosensitive resin composition for a lens by irradiating actinic rays from the other surface side of the substrate Step of forming the lower cladding layer by photocuring or thermosetting the transparent resin composition while being cured Step C: developing and removing uncured portions of the photosensitive resin composition for lenses, and the inside of the through hole Forming a columnar transparent member extending over the outside of one surface of the substrate from step D: heating the columnar transparent member and projecting from the substrate out of the columnar transparent member A step of dripping the tip portion to form a convex lens surface Step E: forming a core layer on the surface of the lower clad layer and forming an upper clad layer on the surface of the core layer Step F: the step of forming the core layer Forming a mirror at a position facing the through hole