JP5278366B2 - Optical waveguide structure and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical waveguide structure having an optical waveguide that enables a greater degree of freedom in pattern shape design, allows a core part (an optical path) to be formed with high dimensional precision by a simple method and is excellent in durability, and an electronic equipment. <P>SOLUTION: An optical waveguide structure 1 includes an optical waveguide 9 formed by layering cladding layers 91 and 92 on both sides of a core layer 93, conductor layers 51 and 52 joined to the both sides respectively, an optical path conversion part 96 bending an optical path of the optical waveguide 9 at substantially right angle, a light emitting element 10 and an electrical element 12. The core layer 93 has a core part 94 and a clad part 95. A layer of the core part 94 is constituted of a composition containing a cyclic olefin resin (A), at least one of a monomer and an oligomer (B), each of which having a cyclic ether group and a different refractive index from a refractive index of the cyclic olefin resin (A), and a photoacid generator (C). The layer of the core part 94 is selectively irradiated with light so that the core part 94 is formed into a desired shape. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an optical waveguide structure and an electronic device.

  In recent years, optical branching couplers (optical couplers), optical multiplexers / demultiplexers, and the like have been developed as optical components in the field of optical communications, and optical waveguide devices used for these are promising. As this optical waveguide type element (hereinafter, also simply referred to as “optical waveguide”), there are polymer optical waveguides that are easy to manufacture (patterning) and are versatile, in addition to conventional quartz optical waveguides. Is being actively developed.

  Such an optical waveguide is usually formed in a predetermined arrangement (pattern) on a substrate and handled as an optical waveguide structure. As this optical waveguide structure, a structure in which a predetermined wiring circuit and an optical waveguide composed of a core portion and a cladding portion are formed on a substrate, and a light emitting element and a light receiving element are attached to the optical waveguide is disclosed. (For example, refer to Patent Document 1).

However, the optical waveguide structure described in Patent Document 1 has the following problems.
1. The process of forming the optical waveguide is complicated, and the degree of freedom in designing and selecting the pattern shape of the core part constituting the optical path of the transmitted light is narrow.
2. The core pattern shape accuracy and dimensional accuracy are poor.
3. When combined with a wiring pattern, the degree of freedom in designing the wiring pattern is narrow.

JP 2004-146602 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical waveguide structure having an optical waveguide with a wide degree of freedom in designing a pattern shape and capable of forming a core portion (optical path) with high dimensional accuracy by a simple method. It is to provide a body and an electronic device.

（式１０１においてｎは、０以上、９以下の整数である。） Such an object is achieved by the present inventions (1) to (6) below.
(1) An optical waveguide including a core layer including a core portion and a pair of clad portions arranged adjacent to each other so as to sandwich the core portion; and an optical path conversion portion that bends the optical path of the core portion. ,
The core part is
(A) a cyclic olefin resin having a repeating unit represented by the following formula (101) ;
(B) At least one of a monomer having a refractive index different from that of (A) and having an oxetanyl group , an oligomer having an oxetanyl group , a monomer having an epoxy group, and an oligomer having an epoxy group ;
(C) a photoacid generator;
Formed into a desired shape by selectively irradiating active radiation to a layer composed of a composition comprising
Refractive index difference of the cladding part and the core part Ri der 0.01 or more,
The composition contains (B) at a ratio of 1 part by weight or more and 50 parts by weight or less with respect to 100 parts by weight of (A),
An optical waveguide structure having a propagation loss of the core portion of 0.10 [dB / cm] or less .

(In Formula 101, n is an integer of 0 or more and 9 or less.)

(2) The optical waveguide structure according to (1) , wherein the concentration of the structure derived from (B) is different between a region irradiated with active radiation of the core layer and an unirradiated region.

(3) The optical waveguide according to (1) or (2) , wherein a region of the core layer irradiated with actinic radiation is at least a part of the cladding part, and an unirradiated region is at least a part of the core part. Structure.
(4) Said (B) is a thing whose refractive index is lower than said (A),
(A) The cyclic olefin resin (A) according to any one of the above (1) to (3), which has a leaving group that is eliminated by an acid generated from the photoacid generator (C). Optical waveguide structure.
(5) The propagation loss of (1) to (4) above, wherein the propagation loss after being subjected to a wet heat treatment for 500 hours in a high temperature and high humidity environment of 85 ° C. and 85% RH is 0.12 [dB / cm] or less The optical waveguide structure according to any one of the above.

(6) An electronic apparatus comprising the optical waveguide structure according to any one of (1) to (5 ) above.

  According to the present invention, the core portion can be patterned by a simple method of light irradiation, and the core portion having a wide degree of freedom in designing the pattern shape of the core portion and high dimensional accuracy can be obtained.

  In addition, when the core layer is made of a desired material, when the stress is applied to the optical waveguide or deformation occurs, particularly even when repeatedly curved and deformed, delamination between the core portion and the cladding portion, Defects such as the occurrence of microcracks in the core are unlikely to occur, and as a result, the optical transmission performance of the optical waveguide is maintained and the durability is excellent.

  Furthermore, when the core part is composed of a resin composition mainly composed of a norbornene resin (cyclic olefin resin), the core part and the cladding part are highly effective in that they are particularly strong against the deformation and hardly cause defects. The difference in refractive index of the optical waveguide can be further increased, and the optical waveguide is excellent in heat resistance. As a result, an optical waveguide having higher performance and durability is obtained.

  In addition, since the optical path conversion unit is provided, the optical path of the transmission light can be bent in a desired direction, which increases the degree of freedom in designing the optical path and contributes to the integration of the optical circuit.

  And when a board | substrate has a translucent part, since the optical path which passes a board | substrate can be formed, the freedom degree of design of an optical path further spreads. Further, when the light transmitting part has a lens part, it is possible to condense and diffuse the transmission light in the optical path as necessary, and the degree of freedom in designing the optical circuit is further expanded in combination with the bending of the optical path.

  When the optical waveguide structure has an element (light emitting element or light receiving element), the light emitted from the light emitting portion of the element is guided to another place by the optical waveguide by being optically connected to the optical waveguide, or Light from other places can be guided to the light receiving portion of the element by the optical waveguide, a small and integrated optical circuit can be formed, and the operation reliability of the optical circuit is also high.

  In addition, when the conductor layer is formed, wiring to the element is easy, and wiring suitable for the element is possible regardless of the type of element (terminal installation location) and the like. Moreover, such a wiring circuit pattern using a conductor layer has a wide degree of freedom in design (for example, a degree of freedom in selection of a terminal installation location).

  Such an optical waveguide structure of the present invention has a wide range of optical circuit (optical waveguide pattern) and electrical circuit design, high yield, high optical transmission performance, excellent reliability and durability, Rich in versatility. Therefore, by providing the optical waveguide structure of the present invention, various highly reliable electronic parts and electronic devices can be obtained.

It is sectional drawing which shows 1st Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 2nd Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 3rd Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 4th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 5th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 6th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 7th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 8th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 9th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 10th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows 11th Embodiment of the optical waveguide structure of this invention. It is a top view which shows 12th Embodiment of the optical waveguide structure of this invention. It is a top view which shows the other structural example of 12th Embodiment. It is a top view which shows the other structural example of 12th Embodiment. It is a perspective view which shows 13th Embodiment of the optical waveguide structure of this invention. It is sectional drawing which shows typically the example of a process of the manufacturing method of an optical waveguide. It is sectional drawing which shows typically the example of a process of the manufacturing method of an optical waveguide. It is sectional drawing which shows typically the example of a process of the manufacturing method of an optical waveguide. It is a figure which shows typically the measuring method of the bending loss in an Example.

  Hereinafter, the optical waveguide structure and electronic device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  1 to 11 are cross-sectional views each showing an embodiment of the optical waveguide structure of the present invention. Hereinafter, a configuration example of the optical waveguide structure will be described with reference to these drawings. In the following description, the upper side in FIGS. 1 to 11 is “upper” or “upper”, and the lower side is “lower” or “lower”. Each figure is exaggerated in the thickness direction of the layer (the vertical direction in each figure).

<First Embodiment: FIG. 1>
As shown in FIG. 1, the optical waveguide structure 1 of the present invention includes an optical waveguide 9, conductor layers 51 and 52 bonded to both surfaces of the optical waveguide 9, and an optical path conversion unit that bends the optical path of the optical waveguide 9. 96, a light emitting element 10, and an electric element 12.

  The optical waveguide 9 is formed by laminating a clad layer (lower clad layer) 91, a core layer 93, and a clad layer (upper clad layer) 92 in this order from the lower side in FIG. A core portion 94 and a clad portion 95 having a predetermined pattern are formed. The core portion 94 is a portion that forms an optical path of the transmission light, and the cladding portion 95 does not form an optical path of the transmission light although it is formed in the core layer 93 and performs the same function as the cladding layers 91 and 92. Part.

  In the configuration shown in FIG. 1, a core portion 94 is formed on the left side in FIG. 1 of a later-described reflective surface 961 of the core layer 93, and a cladding portion 95 is formed on the other portion of the core layer 93. .

  As a constituent material of the core layer 93, a material whose refractive index changes by irradiation with light (for example, ultraviolet rays) or by further heating is used. Preferable examples of such materials include those containing a resin composition containing a cyclic olefin resin such as a benzocyclobutene polymer and a norbornene polymer (resin) as a main material, and include a norbornene polymer (mainly The material) is particularly preferred.

  The core layer 93 made of such a material is excellent in resistance to deformation such as bending, and even when it is repeatedly curved and deformed, the core layer 94 and the clad portion 95 are separated from each other, and the layer adjacent to the core layer 93 ( The delamination with the clad layers 91 and 92) hardly occurs, and the occurrence of microcracks in the core portion 94 and the clad portion 95 is also prevented. As a result, the optical transmission performance of the optical waveguide 9 is maintained, and the optical waveguide 9 having excellent durability is obtained.

  Examples of the constituent material of the core layer 93 include an antioxidant, a refractive index adjuster, a plasticizer, a thickener, a reinforcing agent, a sensitizer, a leveling agent, an antifoaming agent, an adhesion aid, and a flame retardant. The additive may be contained. Addition of an antioxidant has the effect of improving high temperature stability, improving weather resistance, and suppressing light deterioration. Examples of such an antioxidant include phenols such as monophenols, bisphenols, and triphenols, and aromatic amines. Further, the resistance to bending can be further increased by adding a plasticizer, a thickener, and a reinforcing agent.

  The content of additives typified by the antioxidant (the total in the case of two or more) is preferably about 0.5 to 40% by weight, and 3 to 30% by weight with respect to the entire constituent material of the core layer 93. The degree is more preferable. If this amount is too small, the function of the additive cannot be sufficiently exhibited. If the amount is too large, the transmittance of light (transmitted light) transmitted through the core portion 94 depends on the type and characteristics of the additive. Decrease, patterning failure, refractive index instability and the like.

  An example of a method for forming the core layer 93 is a coating method. Examples of the coating method include a method in which a core layer forming composition (varnish or the like) is applied and cured (solidified), and a method in which a curable monomer composition is applied and cured (solidified). In addition, a method other than the coating method, for example, a method of joining separately manufactured sheet materials may be employed.

  The core layer 93 obtained as described above is selectively irradiated with light (active radiation) using a mask to pattern the core portion 94 having a desired shape.

  Examples of light used for exposure include active energy rays such as visible light, ultraviolet light, infrared light, and laser light. Further, instead of using light, electromagnetic waves such as X-rays or particle beams such as electron beams may be used.

  In the core layer 93, the portion irradiated with light has a lower refractive index, and a difference in refractive index occurs between the portion not irradiated with light. For example, a portion of the core layer 93 that is irradiated with light becomes the cladding portion 95, and a portion that is not irradiated becomes the core portion 94. The refractive index of the cladding part 95 is substantially equal to the refractive index of the cladding layers 91 and 92.

  Moreover, the core part 94 may be formed by irradiating the core layer 93 with light in a predetermined pattern and then heating. By adding this heating step, the difference in refractive index between the core portion 94 and the cladding portion 95 becomes larger, which is preferable. This principle will be described later in detail.

  The pattern shape of the core portion 94 to be formed is not particularly limited, and is a straight shape, a shape having a curved portion, an irregular shape, a shape having a branching portion of a light path, a merging portion or a crossing portion, a condensing portion (a width etc. is reduced). Or a light diffusing part (a part where the width or the like is increased), or a combination of two or more of these. A feature of the present invention is that the core portion 94 having any shape can be easily formed by setting the light irradiation pattern.

  The constituent material of each part of the optical waveguide 9 and the method of forming the core part 94 will be described in detail later.

  The conductor layer 51 bonded to the lower surface of the optical waveguide 9 and the conductor layer 52 bonded to the upper surface are each patterned into a predetermined shape to constitute a desired wiring or circuit. Examples of the constituent material of the conductor layers 51 and 52 include various metal materials such as copper, a copper-based alloy, aluminum, and an aluminum-based alloy. Although the thickness of the conductor layers 51 and 52 is not specifically limited, Usually, about 3-120 micrometers is preferable and about 5-70 micrometers is more preferable.

  The conductor layers 51 and 52 are formed by methods such as bonding (adhesion) of metal foil, metal plating, vapor deposition, sputtering, and the like. For example, etching, printing, masking, or the like can be used for patterning the conductor layers 51 and 52.

  The light emitting element 10 includes a light emitting unit 101 and a pair of terminals 103 and 105 on the lower surface side in FIG. The light emitting unit 101 is located between the terminal 103 and the terminal 105. When the terminals 103 and 105 are energized, the light emitting unit 101 emits light.

  In addition, the light emitting part in the light emitting element 10 may be configured by one light emitting point, or may be a group of a plurality of light emitting points. As a set of a plurality of light emitting points, for example, the light emitting points are arranged in a row (for example, 1 × 4, 1 × 12) or in a matrix (for example, n × m: n, m And those in which a plurality of light emitting points are arranged randomly (irregularly). The same applies to a light receiving portion 111 in the light receiving element 11 described later.

  The light emitting element 10 is mounted on the optical waveguide 9 such that the terminals 103 and 105 are respectively joined (electrically connected) to predetermined portions of the conductor layer 52.

  The electric element (electronic circuit element) 12 is composed of, for example, a semiconductor element (semiconductor chip). Although the function of the electric element 12 is not particularly limited, an example is one that constitutes a circuit for driving the light emitting element 10. The electric element 12 has two terminals 123 and 125 on the lower surface side in FIG.

  The electric element 12 is mounted on the optical waveguide 9 such that the terminals 123 and 125 are respectively joined (electrically connected) to predetermined portions of the conductor layer 52.

  The lower part including the terminals 103, 105, 123, and 125 of the light emitting element 10 and the electric element 12 is sealed with the underfill material 4. As a result, the gap between the light emitting element 10 and the electric element 12 and the optical waveguide 9 is sealed with the underfill material 4 without forming a gap. Further, the entire light emitting element 10 and electric element 12 (outer surface) are covered and sealed with the sealing material 6. As described above, the light emitting element 10 and the electric element 12 are entirely sealed, and in particular, the light emitting portion 101 is sealed without being exposed to the outside, so that it is protected from dirt, damage, oxidative degradation, and the like. Contributes to improving the reliability of electronic components.

  The underfill material 4 is made of a material that substantially transmits light (transmitted light) emitted from the light emitting unit 101, and is preferably made of a transparent material.

  As a constituent material of the underfill material 4, an insulating resin material is preferable, and examples thereof include an epoxy resin, a phenol resin, a urethane resin, and a polyimide resin.

  Moreover, as a constituent material of the sealing material 6, an insulating resin material is preferable, and examples thereof include an epoxy resin, a phenol resin, a norbornene resin, and a silicon resin.

  As shown in FIG. 1, the optical waveguide 9 is formed with four through holes (through holes) 8 penetrating in the thickness direction. Each through-hole 8 is filled with a conductive material (for example, various metal materials such as copper, copper-based alloy, aluminum, aluminum-based alloy) to form a conductor post 81. The predetermined portions of the conductor layer 51 and the conductor layer 52 are electrically connected to each other through the conductor posts 81. In other words, the terminals 103, 105, 123, and 125 of the light emitting element 10 and the electric element 12 can be energized through the conductor layer 51 on the lower surface side of the optical waveguide 9. Note that the terminal 105 and the terminal 123 are electrically connected and are connected to the ground side.

  The core portion 94 of the optical waveguide 9 has a pattern shape that overlaps with the light emitting portion 101 of the light emitting element 10 in plan view (when viewed from above in FIG. 1) (that is, passes through directly under the light emitting portion 101). Is formed. The core portion 94 has a higher refractive index than that of the cladding portion 95 and has a higher refractive index than the cladding layers 91 and 92. The clad layers 91 and 92 constitute the clad portions located at the lower part and the upper part of the core part 94, respectively. With such a configuration, the core portion 94 functions as a light guide path surrounded by the clad portion on the entire outer periphery.

  Such an optical waveguide 9 has an optical path conversion section 96 that bends the optical path of the core section 94. The optical path conversion unit 96 includes a reflection surface (mirror) 961 that reflects at least a part of the transmission light. The reflecting surface 961 is provided at a position directly below the light emitting unit 101.

  The reflecting surface 961 is inclined by approximately 45 ° with respect to the optical path of the optical waveguide 9, that is, the longitudinal direction of the core portion 94, and has a function of reflecting most of the transmitted light (for example, 90% or more).

  Such an optical path conversion unit 96 removes (deletes) a part of the optical waveguide 9 to form, for example, a triangular concave portion (hole) whose bottom is the bottom, and reflects one inclined surface thereof. The surface 961 is used. The reflection surface 961 may have a reflection film such as a multilayer optical thin film or a metal thin film (for example, an aluminum vapor deposition film) or a reflection increasing film. Although not shown, the concave portion of the optical path conversion unit 96 may be filled with a filler, particularly a filler having a refractive index different from that of the core 94.

  In the configuration shown in the figure, the reflection surface 961 (the optical path conversion unit 96) is formed across the core layer 93 and the clad layer 92, but may be formed only in the core layer 93.

  In the optical waveguide structure 1 of the present embodiment, when power is supplied between the terminals 103 and 105 of the light emitting element 10 via the conductor layer 51, the conductor post 81, and the conductor layer 52, the light emitting unit 101 emits light, and FIG. The light emitted toward the middle and lower is sequentially transmitted through the underfill material 4 and the clad layer 92, reflected by the reflecting surface 961, bent by 90 °, enters the core portion 94 of the optical waveguide 9, and enters the clad portion (cladding). While repeating reflection at the interfaces with the layers 91 and 92 and the side cladding portions 95), the core portion 94 proceeds in the longitudinal direction (left direction in FIG. 1).

  Further, when energization is performed between the terminals 123 and 125 of the electric element 12 through the conductor layer 51, the conductor post 81, and the conductor layer 52, the electric element 12 is driven.

  In FIG. 1, the leftmost conductor post 81 and the core portion 94 are shown to intersect with each other, but these are shifted in the front-rear direction of the paper surface of FIG. This optical path is designed not to interfere with the conductor post 81.

Second Embodiment: FIG. 2
FIG. 2 shows a second embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st Embodiment, and it demonstrates centering around difference.

  In the optical waveguide structure 1 of the present embodiment, the configuration of the optical path conversion unit 96 is different from that described above, and the other configurations are the same. In other words, the reflection surface (mirror) 961 constituting the optical path conversion unit 96 is located directly below the light emitting unit 101, but this reflection surface 961 is formed in three layers of the clad layer 91, the core layer 93, and the clad layer 92. It is formed across. That is, the triangular concave portion of the optical path conversion unit 96 is open to the lower surface of the optical waveguide 9.

  The reflective surface 961 may have a reflective film or a reflection enhancement film such as a multilayer optical thin film or a metal thin film, or the concave portion of the optical path conversion unit 96 may be filled with a filler. Is the same as described above.

<Third Embodiment: FIG. 3>
FIG. 3 shows a third embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st Embodiment, and it demonstrates centering around difference.

  The optical waveguide structure 1 of this embodiment has a substrate 2, and an optical waveguide 9 is bonded to the lower surface of the substrate 2 via an adhesive layer 3. Similarly to the underfill material 4, the substrate 2 is made of a material that substantially transmits light (transmission light) emitted from the light emitting unit 101 (a material having translucency with respect to the transmission light). A transparent substrate made of a substantially transparent material.

  More specifically, the optical characteristics of the substrate 2 are preferably such that the transmittance of transmitted light is 80% or more, more preferably 90% or more, and even more preferably 95% or more. Since the board | substrate 2 has such an optical characteristic, the site | part just under the light emission part 101 in the board | substrate 2 comprises the translucent part 21 which permeate | transmits transmission light.

  Similarly, the adhesive layer 3 is made of a material that substantially transmits the transmission light emitted from the light emitting unit 101, and is preferably made of a transparent material.

  Examples of the constituent material of the substrate 2 include epoxy resin, phenol resin, bismaleimide resin, bismaleimide / triazine resin, triazole resin, polycyanurate resin, polyisocyanurate resin, benzocyclobutene resin, polyimide resin, polybenzoxazole. Examples thereof include resins and norbornene resins. These materials may be used alone or in combination.

  Further, the substrate 2 may be, for example, a fiber base material (woven fabric, non-woven fabric, woven fabric, knitted fabric, etc.) such as glass fiber or resin fiber impregnated with the above-described resin material (prepreg, etc.). For example, a glass cloth impregnated with an epoxy resin is called a glass epoxy substrate, but such a substrate can be used as the substrate 2. The substrate 2 including such a fiber base material is particularly advantageous when the optical waveguide 9 or the conductor layer (metal layer) is bonded to the substrate 2 because the substrate 2 including the fiber base is relatively thin but has high strength and low thermal expansion coefficient. It is.

  Moreover, the board | substrate 2 may be a laminated body of a some layer. For example, a laminate of a first layer and a second layer made of resin materials having different compositions (kinds), a layer (sheet material) in which the fiber base material is impregnated with a resin material, and a resin material The thing which laminated | stacked the layer is mentioned. In addition, it cannot be overemphasized that the layer structure in a laminated body is not limited to this.

  Although the thickness of the board | substrate 2 is not specifically limited, Usually, about 50 micrometers-1.2 mm are preferable, and about 100-600 micrometers is more preferable.

  The substrate 2 may be hard (rigid) or flexible (flexible). Moreover, you may have both a hard board | substrate and a flexible board | substrate. In this case, the optical waveguide 9 has only to be formed on at least one of a hard substrate and a flexible substrate, and may be formed over both.

  As the adhesive layer 3, a sheet material (bonding sheet) can be used, and examples of the constituent material thereof include an epoxy adhesive, an acrylic adhesive, a phenol resin adhesive, a cyanate resin adhesive, and a maleimide resin. System adhesives and the like. In particular, it is preferably made of a material having flux activity for preventing oxidation or the like.

  The adhesive layer 3 may be formed by a coating film on the lower surface of the substrate 2 or the upper surface of the optical waveguide 9 without using a sheet material as the adhesive layer 3. The adhesive layer 3 may be a laminate of two or more layers.

  Although the thickness of the contact bonding layer 3 is not specifically limited, About 0.5-150 micrometers is preferable and about 10-70 micrometers is more preferable.

  The conductor layer 52 is formed on the upper surface of the substrate 2. In this case, a part of the conductor layer 52 is exposed outward from the sealing material 6. The conductor layer 51 formed on the lower surface of the optical waveguide 9 has a wiring pattern different from that of the first embodiment.

  As shown in FIG. 3, two conductor posts 81 are provided so as to penetrate the optical waveguide 9, the adhesive layer 3, and the substrate 2, and the conductor layer 51 and the conductor layer 52 are predetermined via these conductor posts 81. The parts are conducting. That is, the terminal 105 of the light emitting element 10 and the terminal 123 of the electric element 12 are conducted through the conductor layer 51, the conductor post 81, and the conductor layer 52, and these are connected to the ground side.

  When a current is applied between one conductor layer 52 and the conductor layer 51 exposed to the outside from the sealing material 6, the light emitting portion 101 emits light, and the other conductor layer 52 and the conductor exposed to the outside from the sealing material 6. When energized with the layer 51, the electric element 12 is driven.

  In the optical waveguide structure 1 of the present embodiment, when power is applied between the terminals 103 and 105 of the light emitting element 10 through the conductor layer 51, the conductor post 81, and the conductor layer 52, the light emitting unit 101 is turned on, and FIG. The light emitted toward the middle and lower is sequentially transmitted through the underfill material 4, the substrate 2 (translucent portion of the substrate 2), the adhesive layer 3, and the cladding layer 92, reflected by the reflecting surface 961, and bent by 90 °. The core portion 94 of the optical waveguide 9 enters the core portion 94 while being repeatedly reflected at the interface with the clad portions (cladding layers 91 and 92 and the side clad portions 95). )

<Fourth Embodiment: FIG. 4>
FIG. 4 shows a fourth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st and 3rd embodiment, and it demonstrates centering around difference.

  The optical waveguide structure 1 of this embodiment does not have the adhesive layer 3, except that the substrate 2 and the optical waveguide 9 are directly joined and the configuration of the optical path conversion unit 96 is different. This is the same as the embodiment. Since the board | substrate 2 and the optical waveguide 9 are directly joined, it contributes to thickness reduction of the optical waveguide structure 1. FIG.

  The reflection surface (mirror) 961 constituting the optical path conversion unit 96 is located directly below the light emitting unit 101, but the reflection surface 961 extends over the three layers of the clad layer 91, the core layer 93, and the clad layer 92. Is formed. In other words, the optical path conversion unit 96 is configured by a triangular recess having a base on the upper side, and a reflecting surface 961 is formed on the slope. Such an optical path conversion unit 96 is provided adjacent to the substrate 2.

  The reflective surface 961 may have a reflective film or a reflection enhancement film such as a multilayer optical thin film or a metal thin film, or the concave portion of the optical path conversion unit 96 may be filled with a filler. Is the same as described above.

  In the optical waveguide structure 1 of the present embodiment, when current is passed between the terminals 103 and 105 of the light emitting element 10 through the conductor layer 51, the conductor post 81, and the conductor layer 52, the light emitting unit 101 emits light, and FIG. The light emitted toward the middle and lower is sequentially transmitted through the underfill material 4 and the substrate 2, reflected by the reflecting surface 961, bent by 90 °, enters the core portion 94 of the optical waveguide 9, and enters the cladding portion (cladding layer). 91, 92, and the clad part 95) on the side, and repeats reflection at the interface with the core part 94 along the longitudinal direction (left direction in FIG. 4).

<Fifth Embodiment: FIG. 5>
FIG. 5 shows a fifth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st and 3rd embodiment, and it demonstrates centering around difference.

  The optical waveguide structure 1 of the present embodiment is the same as the third embodiment except for the configuration of the substrate 2. That is, the substrate 2 does not have a sufficient transmission light transmission property, and a through hole 22 penetrating the substrate 2 is formed at a position directly below the light emitting unit 101 in the substrate 2. The through hole 22 constitutes a light transmitting part 21 that transmits the transmitted light. That is, the through hole 22 serves as a light guide for guiding (transmitting) transmission light in the thickness direction of the substrate 2.

  Although not shown in the drawing, the inside (all or a part) of the through-hole 22 is filled with a filler made of a material having a transmission light transmittance of 80% or more, preferably 90% or more, more preferably 95% or more. May be. Although not shown, by forming a layer made of a conductive material on the inner surface of the through hole 22 or the like, in addition to the optical transmission function, a function of transmitting an electrical signal may be provided.

  In the optical waveguide structure 1 of the present embodiment, when power is supplied between the terminals 103 and 105 of the light emitting element 10 through the conductor layer 51, the conductor post 81, and the conductor layer 52, the light emitting unit 101 emits light, and FIG. The light emitted toward the lower middle passes through the underfill material 4, passes through the through hole 22, passes through the adhesive layer 3 and the cladding layer 92, is reflected by the reflecting surface 961, and bends by 90 °. While entering the core portion 94 of the waveguide 9 and repeating reflection at the interface with the cladding portions (cladding layers 91 and 92 and the side cladding portions 95), the inside of the core portion 94 is in the longitudinal direction (left direction in FIG. 5). Proceed along.

<Sixth Embodiment: FIG. 6>
FIG. 6 shows a sixth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st, 4th and 5th embodiment, and it demonstrates centering around difference.

  The optical waveguide structure 1 of this embodiment is obtained by replacing the substrate 2 in the optical waveguide structure 1 of the fourth embodiment with the substrate 2 of the fifth embodiment. That is, the substrate 2 in the optical waveguide structure 1 of the present embodiment does not have a sufficient transmission light transmission property, and a through-hole (substrate 2) that penetrates the substrate 2 at a position directly below the light emitting unit 101. ) 22 in the thickness direction. The through hole 22 constitutes the light transmitting part 21.

  In the optical waveguide structure 1 of the present embodiment, when power is supplied between the terminals 103 and 105 of the light emitting element 10 through the conductor layer 51, the conductor post 81, and the conductor layer 52, the light emitting unit 101 is turned on, and FIG. Light emitted toward the middle and lower passes through the underfill material 4, passes through the through-hole 22, is reflected by the reflecting surface 961, bends 90 °, enters the core portion 94 of the optical waveguide 9, and enters the cladding portion. The light travels along the longitudinal direction (left direction in FIG. 6) in the core portion 94 while repeating reflection at the interfaces with the cladding layers 91 and 92 and the side cladding portions 95.

<Seventh Embodiment: FIG. 7>
FIG. 7 shows a seventh embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st and 5th embodiment, and it demonstrates centering around difference.

  The optical waveguide structure 1 of the present embodiment is different from the fifth embodiment in the configuration of the light transmitting part (light guide path formed in the thickness direction) 21 of the substrate 2, and the other parts are the same as in the fifth embodiment. . That is, a vertical optical waveguide 23 composed of a core portion 24 and a clad portion 25 surrounding the outer periphery of the core portion 24 is inserted into a through hole 22 formed at a position directly below the light emitting portion 101 of the substrate 2. Has been.

  The constituent material and the forming method of the core part 24 can be the same as those of the core part 94. Alternatively, the core part 24 may be the same as the filler in the through hole 22 described in the fifth embodiment. The constituent material of the clad part 25 can be the same as that of the clad part 95 or the clad layers 91 and 92.

  In the optical waveguide structure 1 of the present embodiment, when current is passed between the terminals 103 and 105 of the light emitting element 10 through the conductor layer 51, the conductor post 81, and the conductor layer 52, the light emitting unit 101 emits light, and FIG. The light emitted toward the middle and lower passes through the underfill material 4, passes through the core portion 24 of the vertical optical waveguide 23, passes through the adhesive layer 3 and the cladding layer 92, and is reflected by the reflecting surface 961 to be 90. ° Bends, enters the core portion 94 of the optical waveguide 9, and repeats reflection at the interface with the clad portions (cladding layers 91 and 92 and the side clad portions 95), while passing through the core portion 94 in the longitudinal direction (FIG. 7). (Middle left)

<Eighth embodiment: FIG. 8>
FIG. 8 shows an eighth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st and 6th embodiment, and it demonstrates centering around difference.

  The optical waveguide structure 1 of the present embodiment is the same as that of the seventh embodiment in the configuration of the light guide formed in the thickness direction of the substrate 2 in the optical waveguide structure 1 of the sixth embodiment. is there. That is, a vertical optical waveguide 23 composed of a core portion 24 and a clad portion 25 surrounding the outer periphery of the core portion 24 is inserted into a through hole 22 formed at a position directly below the light emitting portion 101 of the substrate 2. Has been.

  In the optical waveguide structure 1 of the present embodiment, when power is supplied between the terminals 103 and 105 of the light emitting element 10 through the conductor layer 51, the conductor post 81, and the conductor layer 52, the light emitting unit 101 emits light, and FIG. The light emitted toward the middle and lower passes through the underfill material 4, passes through the core portion 24 of the vertical optical waveguide 23, is reflected by the reflecting surface 961, and is bent by 90 °, and the core portion 94 of the optical waveguide 9. Then, while reflecting repeatedly at the interface with the cladding part (cladding layers 91 and 92 and the side cladding part 95), the core part 94 advances in the longitudinal direction (left direction in FIG. 8).

<Ninth Embodiment: FIG. 9>
FIG. 9 shows a ninth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st and 8th embodiment, and it demonstrates centering around difference.

  The optical waveguide structure 1 of the present embodiment is the same as that of the eighth embodiment except that the light transmitting portion 21 is provided with a lens portion 26 that can condense or diffuse transmission light. That is, a lens portion 26 composed of a convex lens (more precisely, a plano-convex lens) is provided on the upper end surface (incident side) of the vertical optical waveguide 23.

  As a result, the light emitted downward from the light emitting unit 101 in FIG. 9 is transmitted through the underfill material 4 and then condensed by the lens unit 26 to narrow the light beam (beam). It passes through the core portion 24 of the optical waveguide 23, is reflected by the reflecting surface 961, is bent by 90 °, enters the core portion 94 of the optical waveguide 9, and passes through the core portion 94 along the longitudinal direction (left direction in FIG. 9). Go ahead. By providing such a lens portion 26, clearer (sharp) transmitted light can be obtained, and more excellent light transmission characteristics can be obtained.

  The lens unit 26 may be capable of diffusing transmitted light. In this case, a concave lens may be used.

  In addition, the installation position of the lens unit 26 is not limited to the position illustrated in FIG. It may be an emission side end.

<Tenth Embodiment: FIG. 10>
FIG. 10 shows a tenth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st, 2nd embodiment, etc., and it demonstrates centering around difference.

  Conductive layers 51 and 52 having a predetermined pattern shape are bonded to the lower surface and the upper surface of the optical waveguide 9 constituted by the clad layers 91 and 92 and the core layer 93 located (interposed) therebetween. The predetermined portions of the conductor layer 51 and the conductor layer 52 are electrically connected to each other by two conductor posts 81 formed through the optical waveguide 9.

  In addition, two optical path conversion parts 96a and 96b are formed in the optical waveguide 9. These optical path conversion units 96a and 96b have reflection surfaces 961a and 961b similar to those described above. In the optical waveguide 9, a core portion 94 is formed on the left side in FIG. 10 from the reflecting surface 961 a of the core layer 93 and the right side in FIG. 10 from the reflecting surface 961 b, and the other portion of the core layer 93 is the cladding portion 95. Is formed.

  A chip carrier (element) 13 is mounted on the optical waveguide 9. The chip carrier 13 includes a substrate 2 ′, an optical waveguide 9 ′ different from the optical waveguide 9, a light emitting element 10, a light receiving element 11, conductor layers 54 and 55, and an electric element 12. Hereinafter, the configuration of the chip carrier 13 will be described in detail.

  An optical waveguide 9 ′ composed of clad layers 91, 92 and a core layer 93 positioned (interposed) therebetween is joined to the lower surface of the substrate 2 ′. In addition, conductor layers 54 and 55 having a predetermined pattern shape are bonded to the upper surface of the substrate 2 ', respectively. Constituent materials, formation methods, patterning methods, and the like of the conductor layers 54 and 55 are the same as those of the conductor layers 51 and 52.

  The substrate 2 'may be substantially transparent or opaque, and may be rigid (rigid) or flexible (flexible).

  Predetermined portions of the conductor layer 54 and the conductor layer 55 are electrically connected to each other by four conductor posts 82 formed through the substrate 2 ′ and the optical waveguide 9 ′.

  Further, four optical path conversion parts 96c, 96d, 96e, 96f are formed in the optical waveguide 9 '. These optical path conversion units 96c, 96d, 96e, and 96f have reflection surfaces 961c, 961d, 961e, and 961f similar to those described above.

  In the optical waveguide 9 ′, a core portion 94 is formed at a portion between the reflecting surface 961 c and the reflecting surface 961 d of the core layer 93 and a portion between the reflecting surface 961 e and the reflecting surface 961 f. The clad part 95 is formed in the other part.

  An electric element (semiconductor element) 12 including four terminals 123, 125, 127, and 129 is mounted on the substrate 2 '. The electric element 12 is mounted on the substrate 2 ′ so that the terminals 123, 125, 127, and 129 are joined (electrically connected) to predetermined portions of the conductor layer 55.

  Although the function of the electric element 12 is not particularly limited, an example is one that constitutes a circuit for driving the light emitting element 10. The electric element 12 may further have a function (circuit) for processing (for example, signal amplification) the electric signal output from the light receiving element 11.

  Such an electric element 12 is entirely covered (sealed) with a sealing material 61 similar to the sealing material 6 and sealed.

  A light emitting element 10 and a light receiving element 11 are mounted below the optical waveguide 9 '. The light emitting element 10 is the same as described above. The light receiving element 11 has a light receiving portion 111 and a pair of terminals 113 and 115 on the upper surface side in FIG. The light receiving unit 111 is located between the terminal 113 and the terminal 115. When the light receiving unit 111 receives light (irradiates transmission light), the light is photoelectrically converted, a potential difference is generated between the terminals 113 and 115, and an electric signal is output.

  The light emitting element 10 is mounted below the optical waveguide 9 ′ such that the terminals 103 and 105 are joined (electrically connected) to predetermined portions of the conductor layer 54. The light receiving element 11 is mounted below the optical waveguide 9 ′ so that the terminals 113 and 115 are respectively joined (electrically connected) to predetermined portions of the conductor layer 54.

  The light emitting element 10 and the light receiving element 11 have their upper portions including the terminals 103, 105, 113, 115 sealed with the underfill material 4, and the light emitting element 10 and the light receiving element 11 as a whole (outer surface) It is covered and sealed with a sealing material 6.

  The core portion 94 of the optical waveguide 9 ′ overlaps the light emitting portion 101 of the light emitting element 10 and the light receiving portion 111 of the light receiving element 11 in plan view (when viewed from above in FIG. 10) (that is, the light emitting portion 101). And a pattern shape (passing right above the light receiving portion 111).

  The reflective surface 961d is provided at a position directly above the light emitting unit 101, the reflective surface 961e is provided at a position directly above the light receiving unit 111, and the reflective surface 961c is at a position directly above the reflective surface 961a. The reflection surface 961f is provided at a position directly above the reflection surface 961b.

  Such a chip carrier 13 is mounted on the optical waveguide 9 such that predetermined portions of the conductor layer 52 and the conductor layer 54 are electrically connected by solder (solder balls) 7. In this case, the space between the optical waveguides 9 and 9 ′ is sealed with an underfill material 41 similar to the underfill material 4.

  A part of the conductor layer 52 is sealed with the underfill material 41, and a part of the conductor layer 52 is exposed to the outside without being sealed with the underfill material 41.

  In the optical waveguide structure 1 of the present embodiment, when power is applied between the terminals 103 and 105 of the light emitting element 10, the light emitting unit 101 emits light, and the light emitted upward in FIG. 4, reflected by the reflecting surface 961 d and bent by 90 °, enters the core portion 94 of the optical waveguide 9 ′, and advances in the core portion 94 along the longitudinal direction (left direction in FIG. 10). Further, the transmission light emitted from the end portion of the core portion 94 is reflected by the reflecting surface 961c, bent 90 °, travels downward, passes through the underfill material 41 and the cladding layer 92, and is reflected by the reflecting surface 961a. It bends by 90 °, enters the core portion 94 of the optical waveguide 9, and advances in the core portion 94 along its longitudinal direction (left direction in FIG. 10).

  On the other hand, the light that enters the core portion 94 from the right side of the optical waveguide 9 in FIG. 10 travels along the longitudinal direction (left direction in FIG. 10) in the core portion 94, is reflected by the reflecting surface 961b, and bends 90 °. Then, it passes upward, passes through the cladding layer 92 and the underfill material 41, is reflected by the reflecting surface 961f, bends 90 °, enters the core portion 94 of the optical waveguide 9 ′, and enters the core portion 94 in its longitudinal direction ( Proceed along the left direction in FIG. Further, the transmission light emitted from the end portion of the core portion 94 is reflected by the reflecting surface 961e, bent 90 °, travels downward, passes through the underfill material 4, and is received by the light receiving portion 111. As a result, a potential difference is generated between the terminals 113 and 115, and an electric signal is output.

<Eleventh embodiment: FIG. 11>
FIG. 11 shows an eleventh embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st, 6th, 10th Embodiment, etc., and it demonstrates centering around difference.

  An optical waveguide 9 composed of clad layers 91 and 92 and a core layer 93 positioned (interposed) therebetween is bonded to the lower surface of the substrate 2. The conductor layer 52 having the pattern shape is joined.

  In addition, two optical path conversion parts 96a and 96b are formed in the optical waveguide 9. The optical path conversion units 96a and 96b have the same configuration as the optical path conversion unit 96 in the fourth, eighth, and ninth embodiments, and have the same reflecting surfaces 961a and 961b, respectively.

  In the optical waveguide 9, a core portion 94 is formed on the left side in FIG. 11 from the reflecting surface 961 a of the core layer 93 and the right side in FIG. 11 from the reflecting surface 961 b, and the other portion of the core layer 93 is the cladding portion 95. Is formed.

  The substrate 2 does not have sufficient transmission light transmission (translucency), and the substrate 2 has a position directly above the reflection surfaces 961a and 961b (a position directly below the reflection surfaces 961c and 961f). Each of the through holes 22 is formed through the substrate 2. These through holes 22 constitute a light transmitting portion 21 that transmits the transmitted light. That is, these through holes 22 serve as a light guide for guiding (transmitting) transmission light in the thickness direction of the substrate 2.

  Moreover, the lens part 26 similar to the said 9th Embodiment is provided in the upper part of both the through-holes 22 (translucent part 21), respectively. For example, the through hole 22 is filled with a transparent first resin material having a relatively low refractive index, and the upper surface thereof is formed into a curved concave surface, and the concave surface is transparent with a higher refractive index than the first resin material. By filling the second resin material, it is possible to form the lens portion 26 in which the portion of the second resin material functions as a convex lens (plano-convex lens, biconvex lens, etc.). In addition, the present invention is not limited thereto, and only a convex lens (a plano-convex lens, a biconvex lens, etc.) may be installed in the through hole 22.

  Moreover, the installation position of the lens part 26 with respect to the through-hole 22 (light-transmitting part 21) is not limited to the upper part as illustrated, and may be in the middle or lower part of the through-hole 22.

  Although not shown in the drawing, the inside (all or a part) of the through-hole 22 is filled with a filler made of a material having a transmission light transmittance of 80% or more, preferably 90% or more, more preferably 95% or more. May be. Further, as in the seventh and eighth embodiments, the vertical optical waveguide 23 may be formed inside the through hole 22.

  A chip carrier (element) 13 similar to that of the tenth embodiment is mounted on the top of the optical waveguide 9 with the substrate 2.

  In the optical waveguide structure 1 of the present embodiment, when power is applied between the terminals 103 and 105 of the light emitting element 10, the light emitting unit 101 emits light, and the light emitted upward in FIG. 4, reflected by the reflecting surface 961 d and bent by 90 °, enters the core portion 94 of the optical waveguide 9 ′, and advances in the core portion 94 along the longitudinal direction (left direction in FIG. 11). Further, the transmission light emitted from the end portion of the core portion 94 is reflected by the reflecting surface 961c, bent 90 °, travels downward, passes through the underfill material 41, and then is condensed by the lens portion 26 and the light flux. (Beam) is narrowed down, this light beam passes through the through hole 22, is reflected by the reflecting surface 961 a, bends 90 °, enters the core portion 94 of the optical waveguide 9, and enters the core portion 94 in its longitudinal direction (FIG. 11). (Middle left)

  On the other hand, the light that enters the core portion 94 from the right side of the optical waveguide 9 in FIG. 11 travels along the longitudinal direction (left direction in FIG. 11) in the core portion 94, is reflected by the reflecting surface 961b, and bends 90 °. Then, the light passes through the through-hole 22 and is condensed by the lens portion 26 to narrow the light beam (beam). The light beam is transmitted through the underfill material 41, reflected by the reflecting surface 961f, and bent by 90 °. Then, the light enters the core portion 94 of the optical waveguide 9 ′ and proceeds along the longitudinal direction (left direction in FIG. 11) in the core portion 94. Further, the transmission light (condensed light beam) emitted from the end of the core portion 94 is reflected by the reflecting surface 961e, bent 90 °, travels downward, passes through the underfill material 4, and is received by the light receiving portion 111. Received light. As a result, a potential difference is generated between the terminals 113 and 115, and an electric signal is output.

<Twelfth embodiment: FIG. 12>
FIG. 12 shows a twelfth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st Embodiment etc., and it demonstrates centering around difference.

  FIG. 12 is a plan view of the optical waveguide structure 1. An optical waveguide 9 (optical waveguide structure 1) having an optical path changing portion shown in FIG. 12 has a branching portion 941 that branches the core portion 94 in a right angle direction in the middle of the core portion 94. A core portion 942 is formed from the branch portion 941 toward the lower side of FIG.

  Further, a through hole 943 that penetrates the optical waveguide 9 in the thickness direction is formed in the branch portion 941. The through hole 943 has a triangular shape in plan view, and one side thereof is formed at an angle (inclination angle) of 45 ° with respect to both the axis of the core portion 94 and the axis of the core portion 942. It functions as an optical path conversion section that bends the optical path of the core section 94. That is, this one side is a reflection surface 944 that reflects a part of the transmission light that passes through the core portion 94. On the other hand, one of the remaining two sides is parallel to the axis of the core portion 94, and the remaining one side is parallel to the axis of the core portion 942.

  At the reflection surface 944, the core portion 94 reflects a part of the transmitted light traveling from the right to the left in FIG. 12, and changes the traveling direction downward. Further, the transmitted light that is not reflected by the reflecting surface 944 travels straight through the branching portion 941 as it is. In this way, the branching unit 941 can branch the transmitted light into two.

  The reflection surface 944 may have a reflection film such as a multilayer optical thin film or a metal thin film (for example, an aluminum vapor deposition film) or a reflection increasing film. Although not shown, the through hole 943 may be filled with a filler, particularly a filler having a refractive index different from that of the core portion 94 or the core portion 942.

  Here, when the filler is not filled in the through-hole 943, air is usually present. The reflection surface 944 bends the optical path of the core portion 94 or the core portion 942 based on the difference between the refractive index of the core portion 94 or the core portion 942 and the refractive index of air. Since the difference in refractive index between the photosensitive resin composition used in the present invention and air is relatively large, the allowable range of the total reflection angle on the reflecting surface 944 is also relatively large. Therefore, based on Snell's law, the inclination angle of the reflecting surface 944 can be set to an angle that totally reflects light propagating through the core portion 94 or the core portion 942. As a result, attenuation of light accompanying reflection at the reflecting surface 944 is suppressed, and a decrease in light propagation efficiency can be suppressed.

  Further, in the branching portion 941, the ratio between the transmission light branched downward and the transmission light traveling straight without being branched is a projected image when the reflecting surface 944 is projected in the direction of the core portion 94 (hereinafter referred to as “reflecting surface”). 944 ”) and the cross-section of the core portion 94 changes. Specifically, if the projected image of the reflecting surface 944 does not completely cover the cross section of the core portion 94, the transmission light at the branching portion 941 can be branched. That is, if the overlapping area between the projected image of the reflecting surface 944 and the cross section of the core portion 94 is smaller than the cross-sectional area of the core portion 94, transmission light that travels straight without being branched at the branching portion 941 is generated. A branch at 941 is possible. The ratio of the overlapping area between the projected image of the reflecting surface 944 and the cross section of the core part 94 to the cross-sectional area of the core part 94 is the ratio of the transmitted light to be branched. In this way, the branching rate at the branching portion 941 can be set simply by setting the area and the formation position of the through-hole 943, so that the branching portion 941 can be easily formed.

13 and 14 are plan views showing other configuration examples of the twelfth embodiment, respectively.
The reflection surface 944 shown in FIG. 13 is configured such that the projection image completely covers the cross section of the core portion 94, and the cross-sectional area of the core portion 94 is the projection image of the reflection surface 944 and the core portion 94. It is the same as the overlapping area with the cross section of. Therefore, in the branching portion 941 shown in FIG. 13, all the transmitted light that passes through the core portion 94 is reflected by the reflecting surface 944.

  Further, the core portion 94 shown in FIG. 13 has a widened portion 945 whose width is increased at the branch portion 941. In the widened portion 945, the outline of the core portion 94 swells so as not to interfere with the through hole 943. Specifically, when an outer extension line (outer part extension line) S of the core portion 94 is assumed in the widened portion 945, both end portions in the inclined direction of the reflecting surface 944 are located outside the extension line S. . With this configuration, the transmission efficiency of the transmission light by the reflection surface 944 is more reliably improved with respect to the transmission light that passes through the core portion 94.

  Further, in this case, in the reflecting surface 944, the vicinity of both end portions in the slope direction with low surface accuracy does not contribute to the reflection of the transmitted light, and the vicinity of the center with high surface accuracy reflects the transmitted light. For this reason, the accuracy of the reflection angle is increased, and unintended reflection is suppressed. As a result, the leakage of a part of the transmitted light reflected at an unintended angle is greatly reduced. It should be noted that, in the vicinity of both end portions in the slope direction of the reflective surface 944, it is inevitable that the processing accuracy is lowered when the through-hole 943 is formed, the surface roughness becomes high, or the inclination angle of the reflective surface 944 Therefore, providing the widened portion 945 is effective from the viewpoint of preventing a decrease in transmission efficiency.

  On the other hand, the core portion 94 shown in FIG. 14 has the same structure as the widened portion 945 shown in FIG. The reflection surface 944 shown in FIG. 14 is configured such that the projected image covers a part of the cross section of the core portion 94. A part of the transmitted light passing through the core portion 94 is reflected at an overlapping portion between the projected image of the reflecting surface 944 and the cross section of the core portion 94, and the remaining transmitted light travels straight without being reflected. Therefore, in the branching unit 941 shown in FIG. 14, the transmission light passing through the core unit 94 can be branched into two.

  Further, when the extension line S of the outline of the core portion 94 is assumed in the widened portion 945 shown in FIG. 14, one of the both end portions in the inclined direction of the reflecting surface 944 is located outside the extension line S. In this case, as in the case of FIG. 13 described above, of the reflecting surface 944, the vicinity of one end of the slope direction with low surface accuracy does not contribute to the reflection of the transmitted light, and the central region with high surface accuracy mainly transmits. Reflect light. For this reason, the accuracy of the reflection angle is increased, and unintended reflection is suppressed. As a result, the leakage of a part of the reflected light to the clad portion 95 is greatly reduced.

  In the above twelfth embodiment, the case where transmission light is reflected by one reflection surface 944 has been described. However, transmission light may be reflected by two or more reflection surfaces 944.

<13th Embodiment: FIG. 15>
FIG. 15 shows a thirteenth embodiment of the optical waveguide structure 1 of the present invention. Hereinafter, although this optical waveguide structure 1 is demonstrated, the description is abbreviate | omitted about the matter similar to the said 1st Embodiment etc., and it demonstrates centering around difference.

  FIG. 15 is a perspective view of the optical waveguide structure 1. In the optical waveguide 9 (optical waveguide structure 1) having the optical path changing portion shown in FIG. 15, the core portion 94 is interrupted at the end portion, and the interrupted portion 946 is a clad portion located on the side of the core portion 94. 95. Then, by removing a part of the interrupted portion 946 of the core layer 93 and a part of each of the clad layers 91 and 92 located on both sides thereof, a triangular recess having the base on the clad layer 91 side is formed. . The width of the recess is equal to or greater than the width of the core portion 94. In addition, one of the two surfaces corresponding to the oblique side of the concave portion is a reflective surface 961.

  Such a reflection surface 961 includes an exposed surface of the cladding layer 91, an exposed surface of the discontinuous portion 946, and an exposed surface of the cladding layer 92. Since these exposed surfaces are all formed by processing a clad material, it is difficult to make a difference in processing rate at the time of processing when the reflecting surface 961 is formed. For this reason, processing unevenness hardly occurs and the reflective surface 961 with high smoothness can be formed. When the smoothness of the reflecting surface 961 is increased, the surface accuracy and optical characteristics of the reflecting surface 961 are improved. Therefore, the reflecting surface 961 can prevent a decrease in transmission efficiency during optical path conversion.

  On the other hand, if the reflective surface 961 includes the exposed surface of the core portion 94, the processing rate is easily different between the core material and the clad material. Accuracy and optical characteristics may be reduced.

  Of the two surfaces corresponding to the hypotenuses of the recesses, the other surface other than the reflective surface 961 may also have a function as a reflective surface.

  Although the first to thirteenth embodiments have been described above, the present invention is not limited to these embodiments, and other configurations may be used as long as the gist of the invention is not changed. Further, the present invention may be a combination of configurations included in any two or more of the first to thirteenth embodiments.

  The optical waveguide structure of the present invention as described above is excellent in light transmission efficiency and durability. For this reason, by providing the optical waveguide structure of the present invention, high-quality optical communication can be performed between two points, and a highly reliable electronic device (electronic device of the present invention) is obtained.

  Note that examples of the electronic device including the optical waveguide structure of the present invention include electronic devices such as a mobile phone, a game machine, a router device, a WDM device, a personal computer, a television, and a home server. In any of these electronic devices, it is necessary to transmit a large amount of data at high speed between an arithmetic device such as an LSI and a storage device such as a RAM. Therefore, since such an electronic device includes the optical waveguide structure according to the present invention, problems such as noise and signal degradation peculiar to electric wiring are eliminated, and a dramatic improvement in performance can be expected.

  In addition, the amount of heat generated in the optical waveguide portion is greatly reduced compared to electrical wiring. Therefore, the degree of integration in the substrate can be increased to reduce the size, the power required for cooling can be reduced, and the power consumption of the entire electronic device can be reduced.

<Optical waveguide manufacturing method>
Next, the manufacturing method of the optical waveguides 9 and 9 ′ and the constituent materials of each part in each of the embodiments will be described. In particular, the method for forming the core part 94 will be described in detail.

  First, prior to the description of the method for forming the core portion 94, the photosensitive resin composition used for forming the core portion 94 will be described.

(Photosensitive resin composition)
The photosensitive resin composition used in this embodiment is
(A) a cyclic olefin resin;
(B) The refractive index is different from (A), and at least one of a monomer having a cyclic ether group and an oligomer having a cyclic ether group;
(C) a photoacid generator;
Is provided.

Among these, from the viewpoint of reliably suppressing the occurrence of light propagation loss,
(C) a cyclic olefin resin (A) having a leaving group capable of leaving by an acid generated from a photoacid generator in the side chain;
It is preferable to contain the monomer of following formula (100).

  Such a photosensitive resin composition is formed into a film to be an optical waveguide forming film, and further used as a film including regions having different refractive indexes, for example, an optical waveguide film.

  That is, by using such a photosensitive resin composition, it is possible to provide an optical waveguide film or the like in which the occurrence of light propagation loss is suppressed. In particular, when a curved optical waveguide is formed, generation of light propagation loss can be remarkably suppressed.

  Furthermore, an optical / electrical hybrid substrate including an optical wiring using such an optical waveguide film, the optical wiring, and an electric circuit can be provided. According to such an optical wiring and an opto-electric hybrid board, it is possible to improve EMI (electromagnetic wave interference), which has been a problem with the conventional electrical wiring, and the signal transmission speed can be greatly improved as compared with the conventional one.

  In addition, an electronic device using the optical waveguide film can be provided. By using the optical waveguide film, space saving can be achieved, which contributes to downsizing of electronic devices.

  Specific examples of such an electronic device include a computer, a server, a mobile phone, a game device, a memory tester, and an appearance inspection robot.

Hereinafter, the components of the photosensitive resin composition will be described in detail.
((A) Cyclic olefin resin)
The cyclic olefin resin of component (A) is added in order to ensure the film moldability of the photosensitive resin composition, and serves as a base polymer.

  Here, the cyclic olefin resin may be unsubstituted, or hydrogen may be substituted with another group.

  Examples of the cyclic olefin resin include norbornene resins and benzocyclobutene resins.

  Especially, it is preferable to use norbornene-type resin from viewpoints, such as heat resistance and transparency.

As norbornene resin, for example,
(1) addition (co) polymer of norbornene type monomer obtained by addition (co) polymerization of norbornene type monomer,
(2) an addition copolymer of a norbornene monomer and ethylene or α-olefins,
(3) an addition polymer such as an addition copolymer of a norbornene-type monomer and a non-conjugated diene and, if necessary, another monomer;
(4) a ring-opening (co) polymer of a norbornene-type monomer, and a resin obtained by hydrogenating the (co) polymer if necessary,
(5) a ring-opening copolymer of a norbornene-type monomer and ethylene or α-olefins, and a resin obtained by hydrogenating the (co) polymer if necessary,
(6) Ring-opening copolymers such as norbornene-type monomers and non-conjugated dienes, or other monomers, and polymers obtained by hydrogenating the (co) polymers as necessary. Examples of these polymers include random copolymers, block copolymers, and alternating copolymers.

  These norbornene resins include, for example, ring-opening metathesis polymerization (ROMP), combination of ROMP and hydrogenation reaction, polymerization by radical or cation, polymerization using cationic palladium polymerization initiator, other polymerization initiators ( For example, it can be obtained by any known polymerization method such as polymerization using a polymerization initiator of nickel or another transition metal).

  Among these, as the norbornene-based resin, an addition (co) polymer is preferable. Addition (co) polymers are also preferred because they are rich in transparency, heat resistance and flexibility. For example, after forming a film with the photosensitive resin composition, an electrical component or the like may be mounted via solder. In such a case, an addition (co) polymer is preferable because it needs to have high heat resistance, that is, reflow resistance. Further, when a film is formed from the photosensitive resin composition and incorporated in a product, it may be used in an environment of about 80 ° C., for example. Even in such a case, an addition (co) polymer is preferable from the viewpoint of ensuring heat resistance.

  Among them, the norbornene-based resin preferably includes a norbornene repeating unit having a substituent containing a polymerizable group or a norbornene repeating unit having a substituent containing an aryl group.

  As the repeating unit of norbornene having a substituent containing a polymerizable group, the repeating unit of norbornene having a substituent containing an epoxy group, the repeating unit of norbornene having a substituent containing a (meth) acryl group, and an alkoxysilyl group At least one of the repeating units of norbornene having a substituent containing is preferable. These polymerizable groups are preferable because of their high reactivity among various polymerizable groups.

  Moreover, if the thing containing 2 or more types of repeating units of norbornene containing such a polymeric group is used, both flexibility and heat resistance can be aimed at.

  On the other hand, by including a norbornene repeating unit having a substituent containing an aryl group, dimensional change due to water absorption can be more reliably prevented by the extremely high hydrophobicity derived from the aryl group.

  Furthermore, the norbornene-based polymer preferably contains an alkylnorbornene repeating unit. The alkyl group may be linear or branched.

  By including the repeating unit of alkyl norbornene, the norbornene-based polymer has high flexibility, and thus can provide high flexibility (flexibility).

  A norbornene-based polymer containing an alkylnorbornene repeating unit is also preferable because of its excellent transmittance with respect to light in a specific wavelength region (particularly, a wavelength region near 850 nm).

  Therefore, as the norbornene-based resin, those represented by the following formulas (1) to (4) and (8) to (10) are preferable.

（式（１）中、Ｒ_１は、炭素数１〜１０のアルキル基を表し、ａは、０〜３の整数を表し、ｂは、１〜３の整数を表し、ｐ_１／ｑ_１が２０以下である。）

(In Formula (1), R ₁ represents an alkyl group having 1 to 10 carbon atoms, a represents an integer of 0 to 3, b represents an integer of 1 to 3, and p ₁ / q ₁ is 20 or less.)

The norbornene-based resin of the formula (1) can be produced as follows.
(1) is obtained by dissolving norbornene having R ₁ and norbornene having an epoxy group in the side chain in toluene and solution polymerization using Ni compound (A) as a catalyst.

  In addition, the manufacturing method of norbornene which has an epoxy group in a side chain is as (i) (ii), for example.

(I) Synthesis of norbornene methanol (NB—CH ₂ —OH) CPD (cyclopentadiene) and α olefin (CH ₂ ═CH—CH ₂ —OH) produced by cracking of DCPD (dicyclopentadiene) are heated under high temperature and high pressure. React.

(Ii) Synthesis of epoxy norbornene It is formed by the reaction of norbornene methanol and epichlorohydrin.

  In the formula (1), when b is 2 or 3, an epichlorohydrin in which the methylene group is an ethylene group, a propylene group or the like is used.

Among the norbornene-based resins represented by the formula (1), from the viewpoint that both flexibility and heat resistance can be achieved, in particular, R ₁ is an alkyl group having 4 to 10 carbon atoms, and a and A compound in which each b is 1, for example, a copolymer of butylbornene and methyl glycidyl ether norbornene, a copolymer of hexyl norbornene and methyl glycidyl ether norbornene, a copolymer of decyl norbornene and methyl glycidyl ether norbornene, or the like is preferable.

（式（２）中、Ｒ_２は、炭素数１〜１０のアルキル基を表し、Ｒ_３は、水素原子またはメチル基を表し、ｃは、０〜３の整数を表し、ｐ_２／ｑ_２が２０以下である。）

(In Formula (2), R ₂ represents an alkyl group having 1 to 10 carbon atoms, R ₃ represents a hydrogen atom or a methyl group, c represents an integer of 0 to 3, and p ₂ / q _2. Is 20 or less.)

The norbornene-based resin of the formula (2) is obtained by dissolving norbornene having R ₂ and norbornene having acryl and methacryl groups in the side chain in toluene, and performing solution polymerization using the Ni compound (A) described above as a catalyst. Can be obtained.

Among the norbornene-based polymers represented by the formula (2), R ₂ is an alkyl group having 4 to 10 carbon atoms and c is 1 from the viewpoint of achieving both flexibility and heat resistance. Compounds such as copolymers of butylbornene and 2- (5-norbornenyl) methyl acrylate, copolymers of hexylnorbornene and 2- (5-norbornenyl) methyl acrylate, decylnorbornene and 2- (5-norbornenyl) methyl acrylate And a copolymer thereof are preferred.

（式（３）中、Ｒ_４は、炭素数１〜１０のアルキル基を表し、各Ｘ_３は、それぞれ独立して、炭素数１〜３のアルキル基を表し、ｄは、０〜３の整数を表し、ｐ_３／ｑ_３が２０以下である。）

(In Formula (3), R ₄ represents an alkyl group having 1 to 10 carbon atoms, each X ₃ independently represents an alkyl group having 1 to 3 carbon atoms, and d represents 0 to 3 carbon atoms. Represents an integer, and p ₃ / q ₃ is 20 or less.)

The resin of the formula (3) can be obtained by dissolving norbornene having R ₄ and norbornene having an alkoxysilyl group in the side chain in toluene, and solution polymerization using the Ni compound (A) described above as a catalyst. it can.

Among the norbornene-based polymers represented by the formula (3), in particular, a compound in which R ₄ is an alkyl group having 4 to 10 carbon atoms, d is 1 or 2, and X ₃ is a methyl group or an ethyl group, For example, a copolymer of butylbornene and norbornenylethyltrimethoxysilane, a copolymer of hexylnorbornene and norbornenylethyltrimethoxysilane, a copolymer of decylnorbornene and norbornenylethyltrimethoxysilane, butylbornene and triethoxysilylnorbornene Copolymer of hexyl norbornene and triethoxysilyl norbornene, copolymer of decyl norbornene and triethoxysilyl norbornene, copolymer of butylbornene and trimethoxysilyl norbornene, hexyl norbornene And copolymers of trimethoxysilyl norbornene, copolymers, etc. of decyl norbornene and trimethoxysilyl norbornene are preferred.

（式中、Ｒ_５は、炭素数１〜１０のアルキル基を表し、Ａ_１およびＡ_２は、それぞれ独立して、下記式（５）〜（７）で表される置換基を表すが、同時に同一の置換基であることはない。また、ｐ_４／ｑ_４＋ｒが２０以下である。）

(In the formula, R ₅ represents an alkyl group having 1 to 10 carbon atoms, and A ₁ and A ₂ each independently represent a substituent represented by the following formulas (5) to (7), (It is not the same substituent at the same time, and p ₄ / q ₄ + r is 20 or less.)

(4) is obtained by dissolving norbornene having R ₅ and norbornene having A ₁ and A ₂ in the side chain in toluene and solution polymerization using Ni compound (A) as a catalyst.

（式（５）中、ｅは、０〜３の整数を表し、ｆは、１〜３の整数を表す。）

(In formula (5), e represents an integer of 0 to 3, and f represents an integer of 1 to 3.)

（式（６）中、Ｒ_６は、水素原子またはメチル基を表し、ｇは、０〜３の整数を表す。）

(In formula (6), R ₆ represents a hydrogen atom or a methyl group, and g represents an integer of 0 to 3.)

（式（７）中、Ｘ_４は、それぞれ独立して、炭素数１〜３のアルキル基を表し、ｈは、０〜３の整数を表す。）

(Equation (7) in, _{X 4} each independently represents an alkyl group having 1 to 3 carbon atoms, h is. Represents an integer of 0 to 3)

  As the norbornene-based polymer represented by the formula (4), for example, any one of butyl norbornene, hexyl norbornene or decyl norbornene, 2- (5-norbornenyl) methyl acrylate, norbornenyl ethyl trimethoxysilane, Terpolymer with either triethoxysilyl norbornene or trimethoxysilyl norbornene, terpolymer of butylbornene, hexylnorbornene or decylnorbornene, 2- (5-norbornenyl) methyl acrylate and methylglycidyl ether norbornene, butylbornene, Either hexyl norbornene or decyl norbornene and methyl glycidyl ether norbornene, norbornenyl ethyltrimethoxysilane, triethoxysilyl Terpolymers, etc. with either Ruborunen or trimethoxysilyl norbornene.

（式（８）中、Ｒ_７は、炭素数１〜１０のアルキル基を表し、Ｒ_８は、水素原子、メチル基またはエチル基を表し、Ａｒは、アリール基を表し、Ｘ_１は、酸素原子またはメチレン基を表し、Ｘ_２は、炭素原子またはシリコン原子を表し、ｉは、０〜３の整数を表し、ｊは、１〜３の整数を表し、ｐ_５／ｑ_５が２０以下である。）

(In formula (8), R ₇ represents an alkyl group having 1 to 10 carbon atoms, R ₈ represents a hydrogen atom, a methyl group or an ethyl group, Ar represents an aryl group, and X ₁ represents oxygen. X ₂ represents a carbon atom or a silicon atom, i represents an integer of 0 to 3, j represents an integer of 1 to 3, and p ₅ / q ₅ is 20 or less. is there.)

Norbornene having R ₇ and norbornene containing-(CH ₂ ) -X ₁ -X ₂ (R ₈ ) _3-j (Ar) _j in the side chain are dissolved in toluene, and solution polymerization is performed using a Ni compound as a catalyst. (8) is obtained.

Of the norbornene polymers represented by the formula (8), those in which X ₁ is an oxygen atom, X ₂ is a silicon atom, and Ar is a phenyl group are preferable.

Further, particularly from the viewpoint of flexibility, heat resistance and refractive index control, R ₇ is an alkyl group having 4 to 10 carbon atoms, X ₁ is an oxygen atom, X ₂ is a silicon atom, Ar is a phenyl group, R _A compound in which ₈ is a methyl group, i is 1 and j is 2, for example, a copolymer of butylbornene and diphenylmethylnorbornenemethoxysilane, a copolymer of hexylnorbornene and diphenylmethylnorbornenemethoxysilane, decylnorbornene and diphenylmethylnorbornenemethoxysilane Of these, the copolymer is preferred.
Specifically, it is preferable to use the following norbornene resin.

（式（９）におけるＲ_７、Ｒ_８，ｐ_５、ｑ_５、ｉは、式（８）と同じである。）

(R ₇ , R ₈ , p ₅ , q ₅ , and i in Formula (9) are the same as in Formula (8).)

From the viewpoint of flexibility, heat resistance, and refractive index control, in Formula (8), R ₇ is an alkyl group having 4 to 10 carbon atoms, X ₁ is a methylene group, X ₂ is a carbon atom, and Ar is Compounds having a phenyl group, R ₈ is a hydrogen atom, i is 0, and j is 1, for example, a copolymer of butylbornene and phenylethylnorbornene, a copolymer of hexylnorbornene and phenylethylnorbornene, a copolymer of decylnorbornene and phenylethylnorbornene Etc.
Further, the following may be used as the norbornene resin.

（式（１０）において、Ｒ_１０は、炭素数１〜１０のアルキル基を表し、Ｒ_１１は、アリール基を示し、ｋは０以上、４以下である。ｐ_６／ｑ_６は２０以下である。）

(In Formula (10), R ₁₀ represents an alkyl group having 1 to 10 carbon atoms, R ₁₁ represents an aryl group, and k is 0 or more and 4 or less. P ₆ / q ₆ is 20 or less. is there.)

P ₁ / q _{1 to} p ₃ / q ₃ , p ₅ / q ₅ , p ₆ / q ₆ or p ₄ / q ₄ + r may be 20 or less, preferably 15 or less, About 0.1-10 is more preferable. Thereby, the effect including the repeating unit of multiple types of norbornene is exhibited.

  The norbornene-based resin as described above preferably has a leaving group. Here, the leaving group is a group that is released by the action of an acid.

  Specifically, those having at least one of an —O— structure, an —Si—aryl structure, and an —O—Si— structure in the molecular structure are preferable. Such an acid leaving group is released relatively easily by the action of a cation.

  Among these, as the leaving group that causes a decrease in the refractive index of the resin by leaving, at least one of the -Si-diphenyl structure and the -O-Si-diphenyl structure is preferable.

For example, among the norbornene polymers represented by the formula (8), those in which X ₁ is an oxygen atom, X ₂ is a silicon atom, and Ar is a phenyl group have a leaving group.

In the formula (3), there is a case where the Si—O—X ₃ part of the alkoxysilyl group is eliminated.

  For example, when the norbornene resin of formula (9) is used, it is presumed that the reaction proceeds as follows by the acid generated from the photoacid generator (denoted as PAG). Here, only the leaving group portion is shown, and the case where i = 1 is described.

Furthermore, in addition to the structure of the formula (9), the side chain may have an epoxy group. By using such a material, there is an effect that a film having excellent adhesion can be formed.
A specific example is as follows.

（式（３１）において、ｐ_７／ｑ_７＋ｒ_２は、２０以下である。）

(In formula (31), p ₇ / q ₇ + r ₂ is 20 or less.)

The compound represented by the formula (31) includes, for example, hexyl norbornene, diphenylmethyl norbornene methoxysilane (norbornene containing -CH ₂ -O-Si (CH ₃ ) (Ph) ₂ in the side chain) and epoxy norbornene in toluene. It can be obtained by dissolving and solution polymerization using a Ni compound as a catalyst.

((B) Monomer having a cyclic ether group, oligomer having a cyclic ether group)
Next, the component (B) will be described.

  Component (B) is at least one of a monomer having a cyclic ether group and an oligomer having a cyclic ether group. This component (B) may have any refractive index different from that of the resin of component (A) and is compatible with the resin of component (A). The refractive index difference between the component (B) and the resin of the component (A) is preferably 0.01 or more.

  The refractive index of the component (B) may be higher than that of the resin of the component (A), but the refractive index of the component (B) is preferably lower than that of the resin of the component (A).

  The monomer having a cyclic ether group and the oligomer having a cyclic ether group as component (B) are polymerized by ring-opening in the presence of an acid. Considering the diffusibility of the monomer and oligomer, the molecular weight (weight average molecular weight) of the monomer and the molecular weight (weight average molecular weight) of the oligomer are preferably 100 or more and 400 or less, respectively.

  Component (B) has, for example, an oxetanyl group or an epoxy group. Such a cyclic ether group is preferable because it is easily opened by an acid.

  As the monomer having an oxetanyl group and the oligomer having an oxetanyl group, those selected from the following formulas (11) to (20) are preferable. By using these, there is an advantage that transparency in the vicinity of a wavelength of 850 nm is excellent and both flexibility and heat resistance are possible. These may be used alone or in combination.

（式（１８）においてｎは０以上、３以下である。）

(In formula (18), n is 0 or more and 3 or less.)

  Among the above monomers and oligomers, they are represented by the formulas (13), (15), (16), (17), and (20) from the viewpoint of ensuring a difference in refractive index from the resin of the component (A). It is preferable to use a compound.

  Furthermore, considering the point that there is a difference in refractive index from the resin of component (A), the point that the molecular weight is small, the mobility of the monomer is high, and the point that the monomer does not easily volatilize, the formulas (20) and (15) It is particularly preferable to use a compound represented by:

  Moreover, as a compound which has an oxetanyl group, the compound represented by the following formula | equation (32) and a formula (33) can be used. As a compound represented by Formula (32), Toagosei Co., Ltd. trade name TESOX etc., and as a compound represented by Formula (33), Toagosei Co., Ltd. trade name OX-SQ etc. can be used.

（式（３３）において、ｎは１または２である）

(In formula (33), n is 1 or 2)

  Examples of the monomer having an epoxy group and the oligomer having an epoxy group include the following. The monomer and oligomer having an epoxy group are polymerized by ring-opening in the presence of an acid.

  As the monomer having an epoxy group and the oligomer having an epoxy group, those represented by the following formulas (34) to (39) can be used. Especially, it is preferable to use the alicyclic epoxy monomer represented by Formula (36)-(39) from a viewpoint that the distortion energy of an epoxy ring is large and is excellent in reactivity.

  In addition, the compound represented by Formula (34) is epoxy norbornene. As such a compound, for example, EpNB manufactured by Promerus Corporation can be used. The compound represented by the formula (35) is γ-glycidoxypropyltrimethoxysilane. As this compound, for example, Z-6040 manufactured by Toray Dow Corning Silicone can be used. The compound represented by the formula (36) is 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and as this compound, for example, E0327 manufactured by Tokyo Chemical Industry can be used.

  Furthermore, the compound represented by the formula (37) is 3,4-epoxycyclohexenylmethyl-3, '4'-epoxycyclohexenecarboxylate. As this compound, for example, Celoxide 2021P manufactured by Daicel Chemical Industries, Ltd. is used. can do. Further, the compound represented by the formula (38) is 1,2-epoxy-4-vinylcyclohexane. As this compound, for example, Celoxide 2000 manufactured by Daicel Chemical Industries, Ltd. can be used.

  Furthermore, the compound represented by the formula (39) is 1,2: 8,9 diepoxy limonene. As this compound, for example, (Celoxide 3000 manufactured by Daicel Chemical Industries, Ltd.) can be used.

  Furthermore, as the component (B), a monomer having an oxetanyl group, an oligomer having an oxetanyl group, a monomer having an epoxy group, and an oligomer having an epoxy group may be used in combination.

  Monomers having an oxetanyl group and oligomers having an oxetanyl group have a slow initiation reaction but a fast growth reaction. On the other hand, a monomer having an epoxy group and an oligomer having an epoxy group have a fast initiation reaction for initiating polymerization, but have a slow growth reaction. Therefore, by using a monomer having an oxetanyl group, an oligomer having an oxetanyl group, a monomer having an epoxy group, and an oligomer having an epoxy group, when irradiated with light, the light irradiated portion and the unirradiated portion A difference in refractive index can be reliably generated.

  The addition amount of the component (B) is preferably 1 part by weight or more and 50 parts by weight or less, more preferably 2 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the component (A). . Thereby, the refractive index modulation between the core and the clad is possible, and there is an effect that both flexibility and heat resistance can be achieved.

((C) Photoacid generator)
Any photoacid generator may be used as long as it absorbs light energy to generate Bronsted acid or Lewis acid. For example, triphenylsulfonium trifluoromethanesulfonate, tris (4-t-butylphenyl) sulfonium- Sulfonium salts such as trifluoromethanesulfonate, diazonium salts such as p-nitrophenyldiazonium hexafluorophosphate, ammonium salts, phosphonium salts, diphenyliodonium trifluoromethanesulfonate, iodonium salts such as (triccumyl) iodonium-tetrakis (pentafluorophenyl) borate, Quinonediazides, diazomethanes such as bis (phenylsulfonyl) diazomethane, 1-phenyl-1- (4-methylphenyl) sulfonyl Sulfonic acid esters such as xyl-1-benzoylmethane and N-hydroxynaphthalimide-trifluoromethanesulfonate, disulfones such as diphenyldisulfone, tris (2,4,6-trichloromethyl) -s-triazine, 2- ( And compounds such as triazines such as 3.4-methylenedioxyphenyl) -4,6-bis- (trichloromethyl) -s-triazine. These photoacid generators can be used alone or in combination.

  The content of the photoacid generator is preferably 0.01 parts by weight or more and 0.3 parts by weight or less with respect to 100 parts by weight of the component (A), and is 0.02 parts by weight or more and 0.2 parts by weight or less. It is more preferable that Thereby, there exists an effect of a reactive improvement.

  The photosensitive resin composition may contain additives such as a sensitizer in addition to the above components (A), (B), and (C).

  The sensitizer increases the sensitivity of the photoacid generator to light and is suitable for reducing the time and energy required for activation (reaction or decomposition) of the photoacid generator and for activating the photoacid generator. It has a function of changing the wavelength of light to a wavelength.

  Such a sensitizer is appropriately selected according to the sensitivity of the photoacid generator and the peak wavelength of absorption of the sensitizer, and is not particularly limited. For example, 9,10-dibutoxyanthracene (CAS No. 76275) is selected. -14-4) anthracenes, xanthones, anthraquinones, phenanthrenes, chrysene, benzpyrenes, fluoranthenes, rubrenes, pyrenes, indanthrines, thioxanthen-9-one (Thioxanthen-9-ones) and the like, and these can be used alone or as a mixture.

  Specific examples of the sensitizer include, for example, 2-isopropyl-9H-thioxanthen-9-one, 4-isopropyl-9H-thioxanthen-9-one, 1-chloro-4-propoxythioxanthone, phenothiazine. Or a mixture thereof.

  The content of the sensitizer in the photosensitive resin composition is preferably 0.01% by weight or more, more preferably 0.5% by weight or more, and further preferably 1% by weight or more. preferable. In addition, it is preferable that an upper limit is 5 weight% or less.

  Among the above photosensitive resin compositions, the cyclic olefin resin having a leaving group in the side chain as the component (A), the photoacid generator of the component (C), and the following formula (100) as the component (B) The photosensitive resin composition containing the 1st monomer as described in above is especially preferable.

Hereinafter, this particularly preferable photosensitive resin composition will be described.
As the cyclic olefin resin (A) constituting the cyclic olefin resin having a leaving group in the side chain, those described above can be used. For example, polymers of monocyclic monomers such as cyclohexene and cyclooctene, Examples include polymers of polycyclic monomers such as norbornene, norbornadiene, dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene, tricyclopentadiene, dihydrotricyclopentadiene, tetracyclopentadiene, and dihydrotetracyclopentadiene. Among these, one or more cyclic olefin resins selected from polymers of polycyclic monomers are preferably used. Thereby, the heat resistance of resin can be improved.

  In addition, as polymerization forms, known forms such as random polymerization and block polymerization can be applied. For example, specific examples of polymerization of norbornene type monomers include (co) polymers of norbornene type monomers, copolymers of norbornene type monomers and other copolymerizable monomers such as α-olefins, A combined hydrogenated product corresponds to a specific example. These cyclic olefin resins can be produced by a known polymerization method. The polymerization methods include an addition polymerization method and a ring-opening polymerization method. Among the above, the cyclic olefin resin (particularly, the addition polymerization method) Norbornene resin) is preferable (that is, an addition polymer of a norbornene compound). Thereby, it is excellent in transparency, heat resistance, and flexibility.

As the leaving group, a part of the molecule is cleaved by the action of an acid (H ⁺ ) generated from a photoacid generator, and then leaves. Specifically, those having at least one of the aforementioned -O- structure, -Si-aryl structure and -O-Si- structure in the molecular structure (side chain) are preferable. The leaving group as described above is released relatively easily by the action of acid (H ⁺ ).

  Among the above-described leaving groups, the leaving group that causes a decrease in the refractive index of the resin by leaving is preferably at least one of a -Si-diphenyl structure and a -O-Si-diphenyl structure.

  The content of the leaving group is not particularly limited, but is preferably 10 to 80% by weight, particularly 20 to 60% by weight in the cyclic olefin resin having a leaving group in the side chain. Is more preferable. When the content is within the above range, it is particularly excellent in both flexibility and refractive index modulation function (effect of increasing the refractive index difference).

  As such a cyclic olefin resin having a leaving group in the side chain, one having a repeating unit represented by the following formula (101) and / or the following formula (102) is preferable. Thereby, the refractive index of resin can be made high.

（式１０１においてｎは、０以上、９以下の整数である。）

(In Formula 101, n is an integer of 0 or more and 9 or less.)

  The photosensitive resin composition includes a monomer described in the above formula (100) (hereinafter referred to as a first monomer). Thereby, the refractive index difference between the left and right cores / claddings can be further expanded.

  The content of the first monomer is not particularly limited, but is preferably 1 part by weight or more and 50 parts by weight or less, particularly 2 parts by weight, based on 100 parts by weight of the cyclic olefin resin having a leaving group in the side chain. It is preferable that it is 20 parts by weight or more. Thereby, the refractive index modulation between the core / cladding is made possible, and both flexibility and heat resistance can be achieved.

  Thus, when the first monomer described above is used in combination with a cyclic olefin resin having a leaving group in the side chain, the reason for excellent balance between the refractive index modulation between the core and the clad and flexibility is as follows. It is considered as follows.

  First, when using the photosensitive resin composition as described above, it is excellent in the refractive index modulation between the core and the clad when the first monomer starts a polymerization reaction by an acid generated by light irradiation or the like. This is because the first monomer is excellent in the reactivity. When the reactivity of the first monomer is excellent, the curability of the first monomer is increased, and the diffusibility of the first monomer caused by the concentration gradient of the first monomer is improved. Thereby, the refractive index difference between the light irradiation region and the non-irradiation region can be increased.

  Further, since the first monomer is monofunctional, the polymerization reaction proceeds and the crosslinking density as the photosensitive resin composition does not become so high. Therefore, it is excellent in flexibility.

  Although the said photosensitive resin composition is not specifically limited, The 2nd monomer different from the said 1st monomer may be included. The second monomer different from the first monomer may be a monomer having a different structure or a monomer having a different molecular weight.

  Especially, the 2nd monomer is contained as a component (B), for example, an oxetane compound different from what is shown by an epoxy compound, Formula (100), a vinyl ether compound, etc. are mentioned. Among these, at least one of an epoxy compound (particularly an alicyclic epoxy compound) and a bifunctional oxetane compound (a monomer having two oxetanyl groups) is preferable. Thereby, the reactivity of the first monomer and the cyclic olefin resin can be improved, whereby the heat resistance of the waveguide can be improved while maintaining transparency.

  Specifically, as the second monomer, the compound of the above formula (15), the compound of the above formula (12), the compound of the above formula (11), the compound of the above formula (18), the compound of the above formula (19) And compounds of the above formulas (34) to (39).

  The content of the second monomer is not particularly limited, but is preferably 1 part by weight or more and 50 parts by weight or less, particularly 2 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the cyclic olefin resin. More preferably. Thereby, the reactivity with the first monomer can be improved.

  Further, the combined ratio of the second monomer and the first monomer is not particularly limited, but is preferably 0.1 to 1 in weight ratio (weight of the second monomer / weight of the first monomer), particularly 0. .1 to 0.6 are preferred. When the combined ratio is within the above range, the balance between the speed of reactivity and the heat resistance of the waveguide is excellent.

  Although content of a photo-acid generator is not specifically limited, It is 0.01 weight part or more and 0.3 weight part or less with respect to 100 weight part of cyclic olefin resin which has a leaving group in the said side chain. In particular, it is more preferably 0.02 parts by weight or more and 0.2 parts by weight or less. If the content is less than the lower limit, the reactivity may decrease, and if the content exceeds the upper limit, the optical waveguide may be colored and light loss may decrease.

  The photosensitive resin composition may contain a curing catalyst, an antioxidant, and the like in addition to the above-mentioned cyclic olefin resin, photoacid generator, first monomer and second monomer.

  Further, the photosensitive resin composition used in the present invention can be used as a composition for forming the core portion 94.

(Optical waveguide manufacturing method)
16 to 18 are cross-sectional views schematically showing process examples of the method for manufacturing an optical waveguide.

  Here, a method for producing an optical waveguide using a photosensitive resin composition when the component (B) has a lower refractive index than the cyclic olefin resin of the component (A) will be described as an example. The method for manufacturing the optical waveguide 9 ′ is the same as that of the optical waveguide 9, and is represented by the optical waveguide 9.

  First, as shown in FIG. 16A, a varnish 900 is prepared by dissolving a photosensitive resin composition in a solvent, and this varnish 900 is applied onto a clad layer 91.

  Examples of the solvent for preparing the photosensitive resin composition in the form of varnish include diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), Ether solvents such as anisole, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl ether (carbitol), cellosolv solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane , Toluene, xylene, benzene, mesitylene and other aromatic hydrocarbon solvents, pyridine, pyrazine, furan, pyrrole, thiophene, methylpyrrolidone and other aromatic heterocyclic compounds Amide solvents such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMA), halogen compound solvents such as dichloromethane, chloroform and 1,2-dichloroethane, ethyl acetate, methyl acetate, ethyl formate, etc. Ester solvents, various organic solvents such as sulfur compound solvents such as dimethyl sulfoxide (DMSO) and sulfolane, or mixed solvents containing them.

  Next, the varnish 900 is applied on the cladding layer 91 of the optical waveguide 9 and then dried to evaporate (desolve) the solvent. As a result, as shown in FIG. 16B, the varnish 900 becomes a film 910 for forming an optical waveguide. The film 910 becomes a core layer 93 in which a core portion 94 and a clad portion 95 are formed by light irradiation described later.

  Here, examples of the method of applying the varnish 900 include a doctor blade method, a spin coating method, a dipping method, a table coating method, a spray method, an applicator method, a curtain coating method, and a die coating method. It is not limited. As the clad layer 91, for example, a sheet having a refractive index lower than that of a core portion 94 described later is used, and for example, a sheet containing a norbornene-based resin and an epoxy resin is used.

Next, the film 910 is selectively irradiated with light (for example, ultraviolet rays).
At this time, as shown in FIG. 17A, a mask M in which an opening is formed is disposed above the film 910. The film 910 is irradiated with light through the opening of the mask M.

  As light used, what has a peak wavelength in the range of wavelength 200-450 nm is mentioned, for example. Thereby, although depending on the composition of the photoacid generator, the photoacid generator can be activated relatively easily.

The irradiation amount of light is not particularly limited, and is preferably about 0.1~9J / cm ^2, more preferably about 0.2~6J / cm ^2, 0.2~3J / More preferably, it is about cm ² .

  Note that the use of the mask M can be omitted when highly directional light such as laser light is used.

  In the region of the film 910 that is irradiated with light, an acid is generated from the photoacid generator. The component (B) is polymerized by the generated acid.

  In the region not irradiated with light, no acid is generated from the photoacid generator, so that component (B) is not polymerized. In the irradiated part, since the component (B) is polymerized to become a polymer, the amount of the component (B) is reduced. In response to this, the component (B) of the unirradiated part diffuses into the irradiated part, thereby causing a difference in refractive index between the irradiated part and the unirradiated part.

  Here, when the component (B) has a lower refractive index than the cyclic olefin resin, the component (B) of the unirradiated part diffuses into the irradiated part, and the refractive index of the unirradiated part increases. The refractive index of the irradiated part is lowered.

  In addition, the refractive index difference between the polymer obtained by polymerizing the component (B) and the monomer having a cyclic ether group is about 0 or more and 0.001 or less, and the refractive indexes are considered to be substantially the same.

  When such a photosensitive resin composition is used, the polymerization of the component (B) can be started by an acid generated from the photoacid generator.

  Furthermore, the cyclic olefin resin used in the present invention does not necessarily have a leaving group, but when a cyclic olefin resin having a leaving group is used as the component (A), The following effects occur.

  In the portion irradiated with light, the leaving group of the cyclic olefin resin is eliminated by the acid generated from the photoacid generator. In the case of a leaving group such as a -Si-aryl structure, a -Si-diphenyl structure, and a -O-Si-diphenyl structure, the refractive index of the resin decreases due to the leaving. Therefore, the refractive index of the irradiated portion is further lowered as compared with that before the leaving group is removed.

  Next, the film 910 is heated. In this heating step, the component (B) of the irradiated portion irradiated with light is further polymerized. On the other hand, in this heating step, the component (B) in the unirradiated part is volatilized. Thereby, in an unirradiated part, a component (B) decreases and it becomes a refractive index close | similar to cyclic olefin resin.

  In this film 910, as shown in FIG. 17B, the region irradiated with light becomes the cladding portion 95, and the non-irradiated region becomes the core portion 94. The structure concentration derived from the component (B) in the core portion 94 and the structure concentration derived from the component (B) in the cladding portion 95 are different. Specifically, the structure concentration derived from the component (B) in the core portion 94 is lower than the structure concentration derived from the component (B) in the cladding portion 95.

  The clad part 95 has a lower refractive index than the core part 94, and the refractive index difference between the clad part 95 and the core part 94 is 0.01 or more. As described above, the core portion 94 and the clad portion 95 are formed on the film 910, and the core layer 93 is obtained.

  The heating temperature in this heating step is not particularly limited, but is preferably about 30 to 180 ° C, and more preferably about 40 to 160 ° C.

  In addition, the heating time is preferably set so that the polymerization reaction of the component (B) of the irradiated part irradiated with light is almost completed, specifically, preferably about 0.1 to 2 hours, More preferably, it is about 0.1 to 1 hour.

  Thereafter, a film similar to the clad layer 91 is attached on the core layer 93. This film becomes the clad layer 92. The pair of clad layers 91 and 92 are arranged so as to sandwich the core portion 94 from a direction different from the clad portion 95.

  The clad layer 92 can also be formed by a method of applying a liquid material on the core layer 93 and curing (solidifying) instead of attaching a film-like one.

Through the above steps, the optical waveguide 9 shown in FIG. 18 is obtained.
Moreover, when the optical waveguide 9 is obtained with the photosensitive resin composition used in the present invention, the solder reflow resistance is particularly excellent. Furthermore, even when the optical waveguide 9 is bent, the optical loss can be reduced.

  In the above description, the case where the photosensitive resin composition is directly supplied onto the clad layer 91 to form the film 910 (core layer 93) has been described, but the film 910 (core layer) is formed on another substrate. 93), the obtained core layer 93 may be transferred onto the clad layer 91 or the clad layer 92, and then the clad layer 91 and the clad layer 92 may be overlapped via the core layer 93. .

Next, the effect of this embodiment is demonstrated.
When light is applied to the photosensitive resin composition used in the present embodiment, an acid is generated from the photoacid generator, and the component (B) is polymerized only in the irradiated portion. Then, since the amount of the component (B) in the irradiated part is reduced, the component (B) in the non-irradiated part diffuses into the irradiated part, thereby causing a difference in refractive index between the irradiated part and the unirradiated part. Specifically, in this embodiment, since a substituted or unsubstituted cyclic olefin resin having a higher refractive index than that of the component (B) is used as the base polymer, the component (B) in the unirradiated portion is irradiated with the irradiated portion. The refractive index of the unirradiated part becomes higher than the refractive index of the irradiated part.

  In addition to this, when the photosensitive resin composition is heated after light irradiation, the component (B) volatilizes from the unirradiated portion. Thereby, a refractive index difference further occurs between the irradiated portion and the unirradiated portion.

  Thus, by using the photosensitive resin composition, a refractive index difference can be reliably formed between the irradiated portion and the unirradiated portion. Further, according to the present invention, the core portion can be patterned by a simple method of simply irradiating light. For example, by appropriately selecting an exposure pattern such as a photomask, an optical path (core part) of any shape and arrangement can be formed, and a thin optical path can be formed sharply. This contributes to integration, and the device can be miniaturized. That is, according to the present invention, a core portion having a wide degree of freedom in designing the pattern shape of the core portion and high dimensional accuracy can be obtained.

  Conventionally, a technique for crosslinking a norbornene-based resin having an oxetanyl group or the like with a thermal acid generator is known. However, the composition used in such a technique contains a norbornene-based resin having an oxetanyl group or the like as a base polymer. And the whole composition is heated and a crosslinked structure is produced in the whole composition. Therefore, this composition that has been conventionally used is selectively irradiated with light to generate acid, thereby selectively causing polymerization, and the monomer diffuses into the region where the monomer concentration is reduced, There is no technical idea that density differences can be made.

  In contrast, when the photosensitive resin composition used in the present embodiment is selectively irradiated with light, the amount of the component (B) in the irradiated portion is reduced due to the generation of acid, so the component (B ) Diffuses to the irradiated part, and as a result, a difference in refractive index occurs between the irradiated part and the unirradiated part.

  Further, when the cyclic olefin resin has a leaving group that is desorbed by an acid generated from the photoacid generator and reduces the refractive index of the cyclic olefin resin of the component (A) by desorption, The refractive index of the region irradiated with light can be reliably reduced as compared with the unirradiated region.

  On the other hand, when the cyclic olefin resin has no leaving group, the side chain is chemically stable, so the refractive index of the core part and the clad part depends on conditions such as light irradiation and heating. Can be prevented from fluctuating.

  Furthermore, in this embodiment, norbornene-type resin is used as a component (A). Thereby, the light transmittance in a specific wavelength can be improved reliably, and reduction of propagation loss can be aimed at reliably.

  Further, the clad part 95 has a lower refractive index than the core part 94, and the difference in refractive index between the clad part 95 and the core part 94 is 0.01 or more, so that light can be reliably confined in the core part 94. And the generation of light propagation loss can be suppressed.

  On the other hand, conventionally, as a composition for forming an optical waveguide, a composition containing a polymer, a monomer, a promoter and a catalyst precursor is known.

  Among these, the monomer can form a reaction product by irradiation of light, and can make the refractive index of the region irradiated with light different from the refractive index of the unirradiated region.

  The catalyst precursor is a substance capable of initiating a monomer reaction (polymerization reaction, crosslinking reaction, etc.), and is a substance whose activation temperature is changed by the action of a promoter activated by light irradiation. Due to the change in the activation temperature, the temperature at which the monomer reaction starts is different between the light irradiation region and the non-irradiation region, and as a result, a reactant can be formed only in the irradiation region.

  Even when such a conventional composition is used, the core part and the clad part can be separately formed by light irradiation. However, according to the photosensitive resin composition used in the present embodiment, the core part 94 and the clad part. Since the difference in refractive index from 95 is further increased and the heat resistance is improved, the optical waveguide 9 having higher reliability can be obtained. This is mainly due to the optimization of the composition of component (A) and component (B).

  It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  Moreover, in the said embodiment, although the photosensitive resin composition was used and the optical waveguide film was formed, you may use for a hologram etc. not only in this. The above-mentioned photosensitive resin composition is suitable for forming a film in which a region having a high refractive index and a region having a low refractive index are mixed.

Next, examples of the present invention will be described.
A. Production of optical waveguide (Example 1)
(1) Synthesis of norbornene-based resin having a leaving group In a glove box filled with dry nitrogen in which the water and oxygen concentrations are both controlled to 1 ppm or less, 7.2 g (40.1 mmol) of hexylnorbornene (HxNB) ), 12.9 g (40.1 mmol) of diphenylmethylnorbornenemethoxysilane was weighed into a 500 mL vial, 60 g of dehydrated toluene and 11 g of ethyl acetate were added, and the top was sealed with a silicon sealer.

  Next, 1.56 g (3.2 mmol) of Ni catalyst represented by the following chemical formula (B) and 10 mL of dehydrated toluene are weighed in a 100 mL vial, put a stirrer chip and sealed, and the catalyst is thoroughly stirred to completely Dissolved in.

  When 1 mL of the Ni catalyst solution represented by the following chemical formula (B) is accurately weighed with a syringe, and quantitatively injected into the vial bottle in which the above two types of norbornene are dissolved and stirred at room temperature for 1 hour, a marked increase in viscosity Was confirmed. At this point, the stopper was removed, 60 g of tetrahydrofuran (THF) was added, and the mixture was stirred to obtain a reaction solution.

  In a 100 mL beaker, 9.5 g of acetic anhydride, 18 g of hydrogen peroxide (concentration 30%) and 30 g of ion-exchanged water were added and stirred to prepare an aqueous solution of peracetic acid on the spot. Next, the total amount of this aqueous solution was added to the above reaction solution and stirred for 12 hours to reduce Ni.

  Next, the treated reaction solution was transferred to a separatory funnel, the lower aqueous layer was removed, and then 100 mL of a 30% aqueous solution of isopropyl alcohol was added and vigorously stirred. The aqueous layer was removed after standing and completely separating the two layers. After repeating this water washing process three times in total, the oil layer was dropped into a large excess of acetone to reprecipitate the polymer produced, separated from the filtrate by filtration, and then in a vacuum dryer set at 60 ° C. Polymer # 1 was obtained by heating and drying for 12 hours. The molecular weight distribution of the polymer # 1 was Mw = 100,000 and Mn = 40,000 by GPC measurement. Moreover, the molar ratio of each structural unit in the polymer # 1 was 50 mol% for the hexylbornene structural unit and 50 mol% for the diphenylmethylnorbornenemethoxysilane structural unit, as determined by NMR. The refractive index was 1.55 (measurement wavelength: 633 nm) by Metricon.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyl oxetane monomer (formula 20) First monomer represented by (Formula 100), Toa Gosei CHOX, CAS # 483303-25-9, molecular weight 186, boiling point 125 ° C./1.33 kPa) 2 g, photoacid generator Rhodorsil Photoinitiator 2074 (manufactured by Rhodia, CAS #) 178233-72-2) (1.36E-2 g in 0.1 mL of ethyl acetate) and uniformly dissolved, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V1. It was.

(3) Production of optical waveguide film (production of lower clad layer)
A photosensitive norbornene resin composition (Avatrel 2000P varnish manufactured by Promeras Co., Ltd.) was uniformly applied on a silicon wafer with a doctor blade, and then placed in a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, the entire coated surface was irradiated with 100 mJ of ultraviolet light and heated in a dryer at 120 ° C. for 1 hour to cure the coating film to form a lower clad layer. The formed lower cladding layer had a thickness of 20 μm, was colorless and transparent, and had a refractive index of 1.52 (measurement wavelength: 633 nm).

(Formation of core layer)
After the photosensitive resin composition varnish V1 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
A dry film in which Avatrel 2000P is laminated in advance on a polyethersulfone (PES) film so as to have a dry thickness of 20 μm is bonded to the above core layer, and put into a vacuum laminator set at 140 ° C. for thermocompression bonding. It was. Thereafter, 100 mJ was irradiated on the entire surface and heated in a dryer at 120 ° C. for 1 hour to cure Avatrel 2000P to form an upper clad layer to obtain an optical waveguide. At this time, the upper cladding layer was colorless and transparent, and its refractive index was 1.52.

(4) Evaluation (Evaluation of optical waveguide loss)
Light emitted from an 850 nm VCSEL (surface emitting laser) was introduced into the optical waveguide via a 50 μmφ optical fiber, received by a 200 μmφ optical fiber, and the light intensity was measured. The cutback method was used for the measurement. When the longitudinal direction of the optical waveguide is taken on the horizontal axis and the insertion loss is plotted on the vertical axis, the measured values are neatly arranged on a straight line, and the propagation loss can be calculated as 0.03 dB / cm from the inclination. .

(Refractive index difference between core and clad)
The refractive index difference between the left and right core portions and the clad portion adjacent in the horizontal direction formed in the above (formation of the core layer) was determined as follows.

  Optical waveguide analyzer OWA-9500 manufactured by EXFO, Canada was used to irradiate the optical waveguide with laser light having a wavelength of 656 nm, and the refractive indexes of the core region and the cladding region were measured, and the difference between them was calculated. As a result, the refractive index difference was 0.02.

(Example 2)
(1) Synthesis of norbornene-based resin having no leaving group In a glove box filled with dry nitrogen in which the water and oxygen concentrations are both controlled to 1 ppm or less, 9.4 g of hexylnorbornene (HxNB) (53. 1 mmol) and 10.5 g (53.1 mmol) of phenylethylnorbornene were weighed into a 500 mL vial, 60 g of dehydrated toluene and 11 g of ethyl acetate were added, and the top was sealed with a silicon sealer.

  Next, weigh 2.06 g (3.2 mmol) of Ni catalyst represented by the above chemical formula (B) and 10 mL of dehydrated toluene in a 100 mL vial, put a stirrer chip and seal tightly, and thoroughly stir the catalyst. Dissolved in.

  When 1 mL of the Ni catalyst solution represented by the chemical formula (B) is accurately weighed with a syringe, and quantitatively injected into the vial bottle in which the two types of norbornene are dissolved and stirred at room temperature for 1 hour, a marked increase in viscosity is observed. confirmed. At this point, the stopper was removed, 60 g of tetrahydrofuran (THF) was added, and the mixture was stirred to obtain a reaction solution.

  In a 100 mL beaker, 9.5 g of acetic anhydride, 18 g of hydrogen peroxide (concentration 30%) and 30 g of ion-exchanged water were added and stirred to prepare an aqueous solution of peracetic acid on the spot. Next, the total amount of this aqueous solution was added to the above reaction solution and stirred for 12 hours to reduce Ni.

  Next, the treated reaction solution was transferred to a separatory funnel, the lower aqueous layer was removed, and then 100 mL of a 30% aqueous solution of isopropyl alcohol was added and vigorously stirred. The aqueous layer was removed after standing and completely separating the two layers. After repeating this water washing process three times in total, the oil layer was dropped into a large excess of acetone to reprecipitate the polymer produced, separated from the filtrate by filtration, and then in a vacuum dryer set at 60 ° C. Polymer # 2 was obtained by heat drying for 12 hours. The molecular weight distribution of the polymer # 2 was Mw = 90,000 and Mn = 40,000 by GPC measurement. The molar ratio of each structural unit in polymer # 2 was 50 mol% for the hexylbornene structural unit and 50 mol% for the phenylethylnorbornene structural unit, as determined by NMR. The refractive index was 1.54 (measurement wavelength: 633 nm) by Metricon.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 2 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of an antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyloxetane monomer (formula 20) 2 g, photoacid generator Rhodorsil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2), manufactured by Toa Gosei Co., Ltd. CHOX, CAS # 48333-3-25-9, molecular weight 186, boiling point 125 ° C./1.33 kPa) (1.36E-2 g, in 0.1 mL of ethyl acetate) was added and dissolved uniformly, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V2.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V2 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.04 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

(Example 3)
(1) Synthesis of norbornene-based resin having a leaving group A norbornene-based resin was produced in the same manner as in Example 1.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, an antioxidant Irganox 1076 (manufactured by Ciba Geigy) 0.01 g, a bifunctional oxetane monomer (formula (15), manufactured by Toa Gosei Co., Ltd., DOX, CAS # 18934-00-4, molecular weight 214, boiling point 119 ° C./0.67 kPa) 2 g, photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia Co., CAS # 178233-) 72-2) (1.36E-2 g in 0.1 mL of ethyl acetate) was added and dissolved uniformly, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V3.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V3 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.04 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

Example 4
(1) Synthesis of norbornene-based resin having a leaving group A norbornene-based resin was produced in the same manner as in Example 1.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of an antioxidant Irganox 1076 (manufactured by Ciba Geigy), an alicyclic epoxy monomer ( Formula (37), manufactured by Daicel Chemical Industries, Celoxide 2021P, CAS # 2386-87-0, molecular weight 252, boiling point 188 ° C./4 hPa) 2 g, photoacid generator Rhodorsil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-) 72-2) (1.36E-2 g in 0.1 mL of ethyl acetate) was added and dissolved uniformly, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V4.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V4 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.04 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

(Example 5)
(1) Synthesis of norbornene-based resin having a leaving group A norbornene-based resin was produced in the same manner as in Example 1.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyl oxetane monomer (formula 20) 1 g of CHOX manufactured by Toagosei Co., Ltd. 1 g of alicyclic epoxy monomer (manufactured by Daicel Chemical Industries, Celoxide 2021P), photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E- 2 g in 0.1 mL of ethyl acetate) and uniformly dissolved, and then filtered through a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V5.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V5 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.03 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

(Example 6)
(1) Synthesis of norbornene-based resin having a leaving group A norbornene-based resin was produced in the same manner as in Example 1.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyl oxetane monomer (formula 20) And 1.5 g of a photoacid generator, Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E-2 g in 0.1 mL of ethyl acetate) and uniformly added. After dissolution, filtration was performed with a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V6.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
After the photosensitive resin composition varnish V6 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.03 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.01.

(Example 7)
(1) Synthesis of norbornene-based resin having a leaving group In a glove box whose water and oxygen concentrations are both controlled to 1 ppm or less and filled with dry nitrogen, 6.4 g (36.1 mmol) of hexylnorbornene (HxNB) ), Diphenylmethylnorbornene methoxysilane (diPhNB) 8.7 g (27.1 mmol), epoxy norbornene (EpNB) 4.9 g (27.1 mmol) were weighed into a 500 mL vial, 60 g of dehydrated toluene and 11 g of ethyl acetate were added, The top was sealed with a silicon sealer.

  Next, 1.75 g (3.2 mmol) of the Ni catalyst represented by the above chemical formula (B) and 10 mL of dehydrated toluene are weighed in a 100 mL vial, put a stirrer chip and sealed, and the catalyst is thoroughly stirred to completely Dissolved in.

  When 1 mL of the Ni catalyst solution represented by the above chemical formula (B) is accurately weighed with a syringe, and quantitatively injected into the vial bottle in which the three types of norbornene are dissolved, and stirred at room temperature for 1 hour, a marked increase in viscosity occurs. Was confirmed. At this point, the stopper was removed, 60 g of tetrahydrofuran (THF) was added, and the mixture was stirred to obtain a reaction solution.

  In a 100 mL beaker, 9.5 g of acetic anhydride, 18 g of hydrogen peroxide (concentration 30%) and 30 g of ion-exchanged water were added and stirred to prepare an aqueous solution of peracetic acid on the spot. Next, the total amount of this aqueous solution was added to the above reaction solution and stirred for 12 hours to reduce Ni.

  Next, the treated reaction solution was transferred to a separatory funnel, the lower aqueous layer was removed, and then 100 mL of a 30% aqueous solution of isopropyl alcohol isopropyl alcohol was added and vigorously stirred. The aqueous layer was removed after standing and completely separating the two layers. After repeating this water washing process three times in total, the oil layer was dropped into a large excess of acetone to reprecipitate the polymer produced, separated from the filtrate by filtration, and then in a vacuum dryer set at 60 ° C. Polymer # 3 was obtained by heat drying for 12 hours. The molecular weight distribution of the polymer # 3 was Mw = 80,000 and Mn = 40,000 by GPC measurement. The molar ratio of each structural unit in polymer # 3 was 40 mol% for the hexylbornene structural unit, 30 mol% for the diphenylmethylnorbornenemethoxysilane structural unit, and 30 mol% for the epoxynorbornene structural unit, as determined by NMR. It was. The refractive index was 1.53 (measurement wavelength: 633 nm) by Metricon.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 3 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of antioxidant Irganox 1076 (manufactured by Ciba Geigy), cyclohexyloxetane monomer (formula 20) 1), CHOX manufactured by Toa Gosei Co., Ltd., and photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E-2 g, in 0.1 mL of ethyl acetate) are uniformly added. After dissolution, filtration was performed with a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish V7.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.
(Formation of core layer)
After the photosensitive resin composition varnish V7 was uniformly applied on the lower clad layer with a doctor blade, it was put into a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a very clear waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad similar to that of Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.04 dB / cm. The refractive index difference between the core portion and the clad portion was 0.02.
The evaluation results of the optical waveguide films obtained in Examples 1 to 7 are shown in Table 1 above.

In Examples 1 to 7, when light is applied to the photosensitive resin composition, an acid is generated from the photoacid generator, and a monomer having a cyclic ether group is polymerized only in the irradiated portion. Since the amount of unreacted monomer in the irradiated portion is reduced, the monomer in the unirradiated portion diffuses into the irradiated portion in order to eliminate the concentration gradient generated between the irradiated portion / unirradiated portion.
Further, when heating is performed after light irradiation, the monomer volatilizes from the unirradiated portion.

  As described above, the structure concentration derived from the monomer is different between the core portion and the cladding portion, the structure derived from the monomer having a cyclic ether group increases in the cladding portion, and the monomer derived from the monomer having a cyclic ether group is present in the core portion. There are fewer structures. This is recognized from the fact that a relatively large refractive index difference of 0.01 or more occurs between the core portion and the cladding portion.

  In Examples 1 to 7, a linear optical waveguide is formed. However, when a curved optical waveguide (with a radius of curvature of about 10 mm) is formed, it is remarkable that optical loss is small.

  Furthermore, the optical waveguide films obtained in Examples 1 to 7 have high heat resistance and have reflow resistance of 260 ° C.

(Example 8)
(1) Synthesis of norbornene resin having a leaving group In the synthesis of a norbornene resin having a leaving group, phenyldimethylnorbornenemethoxysilane was used instead of 12.9 g (40.1 mmol) of diphenylmethylnorbornenemethoxysilane. Example 1 was repeated except that 4 g (40.1 mmol) was used. The molecular weight of the obtained norbornene resin B (Formula 103) having a leaving group in the side chain was Mw = 110,000 and Mn = 50,000 by GPC measurement. The molar ratio of each structural unit was 50 mol% for the hexylnorbornene structural unit and 50 mol% for the phenyldimethylnorbornenemethoxysilane structural unit, as determined by NMR. The refractive index was 1.53 (measurement wavelength: 633 nm) by Metricon.

(2) Production of photosensitive resin composition A photosensitive resin composition was obtained in the same manner as in Example 1 except that the norbornene resin B was used instead of the polymer # 1.

(3) Production of optical waveguide film An optical waveguide film was obtained in the same manner as in Example 1 except that the photosensitive resin composition containing the norbornene-based resin B was used.

  When the loss evaluation of the optical waveguide was performed in the same manner as in Example 1, the propagation loss of the obtained optical waveguide film was 0.03 dB / cm.

Example 9
(1) The procedure was the same as Example 1 except that the following photosensitive resin composition was used.

  10 g of norbornene-based resin obtained in Example 1 was weighed into a 100 mL glass container, and 40 g of mesitylene, 0.01 g of an antioxidant Irganox 1076 (manufactured by Ciba Geigy), and a cyclohexyloxetane monomer (formula (100) represented by formula (100)). 1 monomer, manufactured by Toa Gosei CHOX, CAS # 483303-25-9, molecular weight 186, boiling point 125 ° C./1.33 kPa) 1 g, bifunctional oxetane monomer (second monomer represented by formula (104), manufactured by Toa Gosei, DOX , CAS # 18934-00-4, molecular weight 214, boiling point 119 ° C./0.67 kPa) 1 g, photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E-2 g, ethyl acetate In 0.1 mL) After dissolving one was filtered through 0.2 [mu] m PTFE filter to prepare a photosensitive resin composition varnish for clean core layer.

(2) Production of optical waveguide film An optical waveguide film was obtained in the same manner as in Example 1 except that the photosensitive resin composition of (1) above was used.

  When the loss evaluation of the optical waveguide was performed in the same manner as in Example 1, the propagation loss of the obtained optical waveguide film was 0.04 dB / cm.

(Example 10)
Example 1 was repeated except that the following were used as the cyclic olefin.

(1) Synthesis of norbornene-based resin C Norbornene represented by the following formula (105) is obtained by performing ring-opening metathesis polymerization of phenylethylnorbornene (PENB) monomer using a known method (for example, JP-A-2003-252963). System resin C was obtained.

(2) Production of photosensitive resin composition A photosensitive resin composition was obtained in the same manner as in Example 1 except that the norbornene resin C was used instead of the polymer # 1.

(3) Production of optical waveguide film An optical waveguide film was obtained in the same manner as in Example 1 except that the photosensitive resin composition containing the norbornene-based resin C was used.

  When the loss evaluation of the optical waveguide was performed in the same manner as in Example 1, the propagation loss of the obtained optical waveguide film was 0.05 dB / cm.

(Example 11)
An optical waveguide film was produced in the same manner as in Example 1 except that the amount of the first monomer was changed to 0.5 g.
The propagation loss of the obtained optical waveguide film was 0.10 dB / cm.

(Example 12)
An optical waveguide film was produced in the same manner as in Example 1 except that the blending amount of the first monomer was 4.0 g.
The propagation loss of the obtained optical waveguide film was 0.10 dB / cm.

(Comparative Example 1)
An optical waveguide film was produced in the same manner as in Example 1 except that the first monomer was not used.
The propagation loss of the obtained optical waveguide film was 0.90 dB / cm.

(Comparative Example 2)
(1) Synthesis of each component <Catalyst precursor: Synthesis of Pd (OAc) ₂ (P (Cy) ₃ ) ₂ >
In a 2-neck round bottom flask equipped with a funnel, a reddish brown suspension consisting of Pd (OAc) ₂ (5.00 g, 22.3 mmol) and CH ₂ Cl ₂ (30 mL) was stirred at −78 ° C.

A funnel was charged with a CH ₂ Cl ₂ solution (30 mL) of P (Cy) ₃ (13.12 mL (44.6 mmol)) and added dropwise to the stirred suspension over 15 minutes. As a result, the color gradually changed from reddish brown to yellow.

  After stirring at −78 ° C. for 1 hour, the suspension was warmed to room temperature, stirred for an additional 2 hours, and diluted with hexane (20 mL).

  The yellow solid was then filtered in air, washed with pentane (5 × 10 mL) and dried in vacuo.

  The secondary collection was separated by cooling the filtrate to 0 ° C., washed and dried as above. As a result, a catalyst precursor was obtained.

(2) Production of photosensitive resin composition 10 g of the purified polymer # 1 was weighed into a 100 mL glass container, 40 g of mesitylene, 0.01 g of an antioxidant Irganox 1076 (manufactured by Ciba Geigy), and dimethylbis (norbornenemethoxy). Silane (SiX) 2.4g, the above catalyst precursor (2.6E-2g), photoacid generator Rhodosil Photoinitiator 2074 (manufactured by Rhodia, CAS # 178233-72-2) (1.36E-2g, in ethyl acetate 0.1mL) ) And uniformly dissolved, followed by filtration with a 0.2 μm PTFE filter to obtain a clean photosensitive resin composition varnish.

(3) Production of optical waveguide film (production of lower clad layer)
A lower clad layer similar to that in Example 1 was produced.

(Formation of core layer)
The varnish prepared on the lower clad layer was uniformly applied by a doctor blade, and then placed in a dryer at 45 ° C. for 15 minutes. After completely removing the solvent, a photomask was pressed and selectively irradiated with ultraviolet rays at 500 mJ / cm ² . The mask was removed, and heating was performed in three stages in a dryer at 45 ° C. for 30 minutes, 85 ° C. for 30 minutes, and 150 ° C. for 1 hour. It was confirmed that a waveguide pattern appeared after heating. Moreover, formation of the core part and the clad part was confirmed.

(Formation of upper cladding layer)
An upper clad layer similar to that in Example 1 was produced.

(4) Evaluation Evaluation was performed in the same manner as in Example 1. The propagation loss could be calculated as 0.05 dB / cm. The difference in refractive index between the core portion and the cladding portion was 0.005.

B. Evaluation of Optical Waveguide The following evaluations were performed on the optical waveguides obtained in the examples and comparative examples. The evaluation items are shown together with the contents. The obtained results are shown in Table 2.

1. Light loss Light emitted from an 850 nm VCSEL (surface emitting laser) was introduced into the optical waveguide via a 50 μmφ optical fiber, and received by a 200 μmφ optical fiber to measure the light intensity. The cutback method was used for the measurement, and the waveguide length was plotted on the horizontal axis and the insertion loss was plotted on the vertical axis. The measured values were neatly arranged on a straight line, and the propagation loss was calculated from the slope.

2. Heat resistance The optical waveguide was placed in a high-temperature and high-humidity tank (85 ° C., 85% RH), and propagation loss after 500 hours of wet heat treatment was evaluated. It was also confirmed in parallel presence or absence of degradation of the propagation loss due to reflow process (N ₂ atmosphere, a maximum temperature of 260 ° C. / 60 seconds).
Note that the measurement of the propagation loss here is the same as the one optical loss measurement method.

3. Bending loss of optical waveguide The bending loss of the light intensity of the optical waveguide film having a radius of curvature of 10 mm was evaluated. Light emitted from an 850 nm VCSEL (surface emitting laser) was introduced into the end face of the optical waveguide film via a 50 μmφ optical fiber, and the light intensity was measured from the other end with a 200 μmφ optical fiber (see the following formula) ). The increment of the loss that occurs when the optical waveguide film having the same length is bent is defined as “bending loss”. As shown in FIG. 19, the insertion loss and the optical waveguide film are linear when the optical waveguide film is curved. The “bending loss” is expressed by the difference from the insertion loss when the shape is made.

Insertion loss [dB] =-10 log (emitted light intensity / incident light intensity)
Bending loss = (insertion loss in a curve)-(insertion loss in a straight line)

  As is apparent from Table 2, Examples 1 and 8-12 showed low optical loss and excellent optical waveguide performance.

  Moreover, Examples 1 and 8-12 showed that the light loss after a high-temperature, high-humidity process and a reflow process was also small, and it was excellent in heat resistance.

  In particular, Examples 1, 8, 9, and 10 have a small bending loss, and it was suggested that sufficient performance was exhibited even when the optical waveguide was bent.

  Furthermore, when the optical waveguide structure according to the first embodiment was produced using the optical waveguide film obtained in each example and comparative example, the optical waveguide using the optical waveguide film obtained in each example was produced. A structure having a low transmission loss was obtained as compared with the optical waveguide structure using the optical waveguide film obtained in each comparative example.

DESCRIPTION OF SYMBOLS 1 Optical waveguide structure 2, 2 'board | substrate 21 Translucent part 22 Through-hole 23 Vertical optical waveguide 24 Core part 25 Clad part 26 Lens part 3 Adhesive layer 4, 41 Underfill material 51, 52, 54, 55 Conductor layer 6, 61 Sealing material 7 Solder 8 Through hole (through hole)
81, 82 Conductor post (conductive material)
9, 9 'Optical waveguide 91 Clad layer 92 Clad layer 93 Core layer 94 Core part 95 Clad part 96 Optical path conversion part 961 Reflecting surface 96a, 96b, 96c, 96d, 96e, 96f Optical path conversion part 961a, 961b, 961c, 961d, 961e, 961f Reflecting surface 10 Light emitting element 101 Light emitting part 103 Terminal 105 Terminal 11 Light receiving element 111 Light receiving part 113 Terminal 115 Terminal 12 Electric element (semiconductor element)
123 terminal 125 terminal 127 terminal 129 terminal 13 chip carrier 900 varnish 910 film 941 branch part 942 core part 943 through hole (hole)
944 Reflecting surface 945 Widened portion 946 Interrupted portion M Mask S Stretched line

Claims (6)

An optical waveguide including a core layer including a core portion and a pair of clad portions arranged adjacent to each other so as to sandwich the core portion; and an optical path conversion portion that bends the optical path of the core portion,
The core part is
(A) a cyclic olefin resin having a repeating unit represented by the following formula (101) ;
(B) At least one of a monomer having a refractive index different from that of (A) and having an oxetanyl group , an oligomer having an oxetanyl group , a monomer having an epoxy group, and an oligomer having an epoxy group ;
(C) a photoacid generator;
Formed into a desired shape by selectively irradiating active radiation to a layer composed of a composition comprising
Refractive index difference of the cladding part and the core part Ri der 0.01 or more,
The composition contains (B) at a ratio of 1 part by weight or more and 50 parts by weight or less with respect to 100 parts by weight of (A),
An optical waveguide structure having a propagation loss of the core portion of 0.10 [dB / cm] or less .

(In Formula 101, n is an integer of 0 or more and 9 or less.) A region in which actinic radiation of the core layer is irradiated, in a non-irradiated region, the (B) an optical waveguide structure of claim 1 wherein different structure levels derived. At least a portion, and an optical waveguide structure according to the non-irradiated regions to claim 1 or 2, at least a portion of the core portion of the cladding portion an area in which the active radiation is irradiated in the core layer. (B) has a lower refractive index than (A),
  The optical waveguide structure according to any one of claims 1 to 3, wherein the cyclic olefin resin (A) has a leaving group that is eliminated by an acid generated from the photoacid generator (C). body. The optical loss according to any one of claims 1 to 4, wherein a propagation loss after being subjected to a wet heat treatment in a high temperature and high humidity environment of 85 ° C and 85% RH for 500 hours is 0.12 [dB / cm] or less. Waveguide structure. An electronic apparatus comprising the optical waveguide structure according to any one of claims 1 to 5.

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