JP4284233B2 - Method for manufacturing optical waveguide structure - Google Patents

Description

The present invention relates to a method for manufacturing an optical waveguide structure. More specifically, the present invention relates to a method for manufacturing an optical waveguide structure including an optical path conversion unit in which light leakage and scattering loss are suppressed.

  In the information processing field, the information communication field, and the like, the amount of data to be handled is increasing, and it is predicted that the data amount will increase in the future. Accordingly, the communication speed is required to increase. For this reason, it is desired to shift to processing using an optical signal having a processing speed higher than that of an electrical signal. In particular, in recent years, not only signal transmission paths with long transmission distances typified by optical communication cables and dedicated devices associated therewith, but also short signal transmission paths such as connections of boards and electronic components in general-purpose electronic equipment, The transition from electrical transmission media to optical transmission media is being considered. In this new information processing and information communication, there are an optical waveguide structure formed from an organic material and an optical waveguide device using the optical waveguide structure because of excellent material properties such as processability and flexibility, and cost. Attention has been paid.

  In general, an optical waveguide structure includes a core portion through which light propagates, a clad portion for confining light in the core portion, and an optical path changing portion. Of these, the optical path conversion unit is a part that converts the optical path of the propagating light, and is an important part in which the loss and accuracy of light propagation are greatly affected by the accuracy. As a method of forming this optical path changing portion, a method of forming the optical path changing portion by cutting out a part of the core portion by dicing (see Patent Document 1), a mirror is provided on the optical axis of the optical exit port of the core portion. There are known a mounting method (Patent Document 2), a method of mounting an optical path changing unit at a desired position, and then embedding it in a core part using a spin coating method (see Patent Documents 3 and 4 below).

Japanese Patent Laid-Open No. 10-300961 JP 2002-082244 A Japanese Patent Application Laid-Open No. 2003-50329 (page 7, FIG. 7, etc.) Japanese Patent Laid-Open No. 2002-107561 (page 4, FIG. 3, etc.)

The method of Patent Document 1 is simple because it does not use other members such as an optical path conversion member. However, it is difficult to dice only one portion of a desired optical path changing portion in the core portion. That is, usually, the substrate having the core portion must be diced so as to cross a straight line, and the degree of freedom of the formation position of the optical path changing portion is greatly limited. For this reason, it is difficult to achieve higher density and higher integration than the conventional electric circuit as described above.
Further, the method of Patent Document 2 is excellent in that the mirror can be arranged at a desired position and the degree of freedom of the formation position of the optical path conversion portion is high. However, since there is a gap between the optical exit port and the mirror, there is light leakage. In particular, when the number of optical path conversion units increases, the loss may not be negligible.
Furthermore, in the methods of Patent Documents 3 and 4, the core portion and the like are formed on the optical path changing portion in order to use the spin coating method. For this reason, it is necessary to provide a polishing process. However, it is difficult to polish an organic material, and it is necessary to harden it before polishing, which limits the freedom of processes such as requiring a sequential curing process. Furthermore, there is a problem that it is difficult to control the shape of the core near the optical path changing part. That is, for example, in Patent Document 3, the lower clad portion formed by spin coating substantially covers the optical path changing portion, and the optical path is changed in the intended direction even if the core portion is formed on the lower clad portion. May cause problems such as difficulty.

The present invention has been made in view of the above problems, and has a high degree of freedom in design such as the formation position of the optical path conversion section, can prevent light leakage, can perform accurate optical path conversion, and further has problems caused by using the spin coating method. It is an object of the present invention to provide a method of manufacturing an optical waveguide structure that can be easily and accurately designed with a high degree of freedom.

  The inventors of the present invention are a conventional manufacturing method including a step of spin-coating an uncured lower clad portion on the surface of a laminate including an optical path changing portion formed on or arranged on a base. It was found that light leakage was observed in the formed waveguide structure. And the method of preventing this light leakage was examined. As a result, when the uncured lower clad part is applied and formed using a liquid material having a low viscosity, since the optical path conversion part is already formed on the base, these liquid materials adhere to the surface of the optical path conversion part. Alternatively, it has been found that, in the subsequent formation of the core portion, it may be impeded that the shape, position, and the like are desired. The present invention has been made based on these findings.

That is, the present invention is as follows.
(1) A lower clad part, a core part disposed on the lower clad part and transmitting light, an upper clad part disposed on the core part, and a part thereof are disposed in the lower clad. And a method of manufacturing an optical waveguide structure comprising: an optical path conversion unit that converts an optical path of light propagating through the core unit;
An uncured lower clad part forming step for forming an uncured lower clad part to be the lower clad part;
And an optical path conversion component embedding step for embedding a part of a previously formed optical path conversion component to be the optical path conversion portion into the uncured lower clad portion. Manufacturing method.
(2) The optical waveguide structure further includes a base below the lower clad portion,
In the uncured lower cladding portion forming step, the uncured lower cladding portion is formed on the base portion.
(3) The method for manufacturing an optical waveguide structure according to (2), wherein the uncured lower clad part is formed by pressure bonding an uncured film for forming a lower clad part to the base.
(4) Further, after the optical path conversion component embedding step, the uncured lower clad part semi-curing step for semi-curing the uncured lower clad portion to form a semi-cured lower clad portion;
A core part forming step of forming the core part on the semi-cured lower clad part;
An uncured upper clad part forming step for forming an uncured upper clad part to be the upper clad part on the core part after the core part forming step;
(1) to (3) including a collective curing step of collectively curing the laminate including the semi-cured lower clad portion, the core portion, and the uncured upper clad portion after the uncured upper clad portion forming step. The manufacturing method of the optical waveguide structure in any one of these.
(5) The optical waveguide structure according to (4), further including a core portion forming uncured film disposing step of disposing a core portion forming uncured film serving as the core portion on the semi-cured lower clad portion. Body manufacturing method.
(6) Further, after the optical path conversion component embedding step, the uncured lower clad portion curing step for obtaining the lower clad by curing the uncured lower clad portion,
A core portion forming step for forming the core portion after the uncured lower clad portion hardening step;
The method for manufacturing an optical waveguide structure according to any one of (1) to (3), further comprising: an upper clad portion forming step of forming the upper clad portion after the core portion forming step.
(7) In the core part forming step, the core part forming uncured film disposing step of disposing a core part forming uncured film serving as the core part on the lower clad part is described in (6) above. Manufacturing method of the optical waveguide structure.
(8) The optical path conversion component is made of metal and is formed by pressing a supplied metal lump using a stamping jig into a predetermined shape. A method for producing an optical waveguide structure according to claim 1.
(9) The method for manufacturing an optical waveguide structure according to any one of (1) to (8), wherein the embedding is performed by heating the temperature of the uncured lower clad portion to 30 to 120 ° C.

According to the method for manufacturing an optical waveguide structure of the present invention, it is possible to easily and accurately perform a design with a high degree of freedom without causing a core portion formation hindrance due to the lower clad portion adhering to the optical path conversion component. Therefore, it can manufacture efficiently and is excellent in versatility and mass productivity. In the obtained optical waveguide structure, light leakage is prevented, and accurate and highly efficient optical path conversion can be performed.
When the optical waveguide structure including the base is obtained by forming the uncured lower clad portion on the base, the optical waveguide structure having the above-described effect including the base can be easily obtained.
In the case of including the base removal step, an optical waveguide structure having the above-described effect without a base can be easily obtained, and the obtained optical waveguide structure can be used as a manufacturing part of an optical waveguide device.
When the uncured film for forming the lower clad part is pressure-bonded to the base, it is possible to accurately perform a design that is excellent in work efficiency and more easily and has a high degree of freedom. Therefore, it is excellent in versatility and mass productivity.
When an uncured lower clad part semi-curing step, a core part forming step, an uncured upper clad part forming step, and a collective curing step are provided, an optical waveguide structure having the above effects can be obtained easily and efficiently with a small number of steps. it can. Therefore, it is excellent in versatility and mass productivity.
In addition to the uncured lower clad part semi-curing process, core part forming process, uncured upper clad part forming process and batch curing process, it is excellent in work efficiency and more simple. Therefore, it is possible to accurately design with a high degree of freedom. Therefore, it is excellent in versatility and mass productivity.
When the uncured lower clad portion curing step, the core portion forming step, and the upper clad portion forming step are provided, the core portion pattern can be formed more accurately and simply.
In addition to the uncured lower clad part curing process, core part forming process, and upper clad part forming process, when equipped with an uncured film forming process for forming a core part, it is excellent in work efficiency and more easily designed with a high degree of freedom. Can be done accurately. Therefore, it is excellent in versatility and mass productivity.
According to the optical waveguide structure, the release sheet can be easily peeled off, and an optical waveguide device excellent in versatility and mass productivity can be obtained simply by using it as a manufacturing component. Furthermore, by using the manufacturing method of the present invention, light leakage is prevented, and a structure capable of performing an accurate and highly efficient optical path conversion is obtained.

Hereinafter, the present invention will be described in detail.
[1] Optical waveguide structure An optical waveguide structure obtained by the manufacturing method of the present invention includes a lower clad part, a core part disposed on the lower clad part and propagating light, and on the core part. An upper clad portion that is disposed; and an optical path conversion portion that is partially disposed in the lower clad and converts an optical path of light propagating through the core portion.

  The “lower cladding part” and the “upper cladding part” are parts constituting the cladding part, respectively. The clad portion is a portion surrounding the core portion, and is a portion capable of reflecting light propagating in the core portion at the interface with the core portion. For example, the clad portion can obtain this effect by making the refractive index smaller (usually 0.2% or more) than the core portion. The lower clad part and the upper clad part may have the same refractive index or different ones.

Also, the lower clad part is a clad part that is already formed before the core part or the uncured core part is formed, or an uncured part that is already formed before the core part or the uncured core part is formed. This is a clad portion obtained by curing the clad portion. On the other hand, the upper clad portion cures the clad portion formed simultaneously with the formation of the core portion or the uncured core portion, and the uncured clad portion formed simultaneously with the formation of the core portion or the uncured core portion. The clad part formed after the clad part, the core part or the uncured core part is formed, or the uncured clad part formed after the core part or the uncured core part is formed is cured. It is the clad part obtained in this way.
Therefore, for example, a portion disposed below a lower end surface (one surface facing the lower cladding portion) of the core portion described later is a lower cladding portion, and a portion disposed above the lower end surface of the core portion is an upper portion. It can be a clad part.

Moreover, each of these lower clad part and upper clad part may be formed in steps for every predetermined part.
That is, for example, the upper clad portion may be divided into an intermediate clad portion that fills between the core patterns and an uppermost clad portion disposed above the upper end surface of the core portion.

  The material which comprises a clad part is not specifically limited. Further, the lower clad part and the upper clad may be made of the same material, or may be made of different materials. Further, for example, when the upper clad part is composed of the intermediate clad part and the uppermost clad part as described above, these may be made of the same material or may be made of different materials. Good. Furthermore, the core part and the clad part to be described later may be made of the same material or different materials.

Although the material which comprises these clad parts is not specifically limited, Usually, it is an organic type material. Examples of organic materials include acrylic resins, epoxy resins, polyimide resins, fluororesins, bismaleimide resins, polyphenylene ether resins, phenol resins, silicone resins, urethane resins, polyester resins, phenoxy Resin and polyolefin resin can be used. In addition, each halogenated resin in which at least a part of hydrogen atoms included in each of these resins is substituted with a halogen atom (substitution with at least one of F, Cl and Br is preferable, and substitution with F is particularly preferable), Each deuterated resin in which at least a part of hydrogen atoms provided in the resin is substituted with deuterium atoms can be used. Among these, acrylic resins, epoxy resins, halogenated acrylic resins, halogenated epoxy resins, deuterated acrylic resins, and deuterated epoxy resins are preferable. Among these, fluorinated acrylic resins, fluorinated epoxy resins, deuterated acrylic resins, and deuterated epoxy resins are more preferable. These resins may be used alone or in combination of two or more.
Moreover, the shape (cross-sectional shape etc.) of a lower clad part and an upper clad part is not specifically limited.

  The “core part” is a part through which light propagates. The material constituting the core part is not particularly limited, and an inorganic material may be used. However, it is preferable to use an organic material because it is easy to process and has excellent flexibility. The organic material is usually formed from a cured resin cured using light. As this curable resin, various resins mentioned as the organic resin constituting the clad portion can be used. Among these, an epoxy resin and an acrylic resin are preferable. When the core part is made of an epoxy resin, the optical waveguide device is particularly excellent in heat resistance, insulation, chemical resistance and water resistance. Moreover, when a core part consists of acrylic resin, it is excellent in especially photosensitivity and transparency. These resins may be used alone or in combination of two or more.

  The planar shape of the core part is not particularly limited, and may be linear or curved. Furthermore, you may have a branch. Further, the cross-sectional shape (cross-section with respect to the light propagation direction) is not particularly limited, and may be a quadrangle (such as a square or a rectangle) or a circle. Moreover, it can also be made into polygons other than a rectangle, and cross-sectional shape which is not perfect circles like an ellipse etc. may be sufficient.

  The refractive index of the core part may be a substantially uniform refractive index or may have different parts regardless of the type of resin constituting the core part and the number of types. . Note that the core portion has a portion with a different refractive index, for example, when the refractive index at the center of the core portion is maximum and the refractive index decreases as it approaches the cladding portion. Further, the refractive index may be different or the same between different types of resins, and even a resin derived from the same monomer changes depending on the degree of polymerization. Therefore, the uniform refractive index portion and the different refractive index portion may be obtained from the same kind of resin or from different kinds of resins.

  The light transmission characteristics of the core portion are not particularly limited, and any light such as infrared rays (including near infrared rays), visible rays, and ultraviolet rays can be transmitted. Especially, it is preferable that it is what can permeate | transmit a near infrared ray (0.7-25 micrometers) especially, and it is more preferable that it is a thing suitable for transmission of a near infrared ray (0.7-2 micrometers).

  The “optical path conversion part” is a part that is partly disposed in the lower clad and converts the optical path of light propagating through the core part. This optical path conversion part consists of optical path conversion components, and only one optical path conversion component may be disposed in the optical waveguide structure, or two or more optical path conversion components may be disposed. In addition, as shown in FIGS. 4 and 5, the above “part is disposed in the lower cladding” means that a part of the optical path conversion component is disposed in the lower cladding in the case of having a base to be described later. Further, it may be disposed on the surface of the base (see FIG. 4), or a part of the optical path conversion component may be disposed in the lower clad and disposed above the base without contacting the base (see FIG. 5). . Among these, since it is easy to control the positional accuracy of the optical path conversion unit, it is preferable that the optical path conversion unit is disposed on the base surface.

  The shape of the optical path conversion component serving as the optical path conversion unit is not particularly limited as long as the optical path can be converted. As this shape, for example, a polygonal prism such as a triangular prism or a quadrangular prism having an inclined reflecting surface may be used. One optical path conversion unit may have one reflecting surface or two or more reflecting surfaces. When an optical path conversion component having two or more reflecting surfaces is used, higher density and higher integration can be achieved by utilizing a plurality of reflecting surfaces. Further, the direction of the optical path conversion by the optical path conversion component is not limited. For example, the optical path conversion in the core may be performed, or the optical path conversion to the outside of the core may be performed.

Further, the optical path conversion component may be formed of any material as long as it has the reflection surface. That is, for example, it is preferable that at least the reflective surface is formed of a material having high reflectivity such as metal. Of these, gold, silver, copper, rhodium, nickel and the like are preferable. These may use only 1 type and may use 2 or more types together. Moreover, what consists only of the said metal may be sufficient, and only a reflective surface may consist of the said metal. When only the reflective surface is made of the above metal, the other part may be made of an inorganic material other than the above metal or an organic material.
The method for forming the optical path conversion component is not limited. That is, for example, when the optical path conversion component is made of metal, a metal lump is supplied from a capillary or the like to the surface of a removable substrate or the like, and is pressed into a predetermined shape using a stamping jig or the like, Next, the optical path conversion component can be obtained by peeling the substrate.

  Further, in the optical waveguide structure, it is preferable that the uppermost portion of the optical path changing portion is formed so as to be flush with the upper surface of the core portion or protrude from the upper surface of the core portion. In this case, for example, an optical waveguide structure in which the occurrence of light leakage and scattering loss due to light propagating in the core portion around the back surface with respect to the reflection surface of the optical path changing portion is sufficiently suppressed.

The waveguide structure can include other parts in addition to the lower clad part, the core part, the upper clad part, and the optical path conversion part. Examples of the other part include a base part.
This base portion is a portion provided under the lower clad portion, and is integrally formed and may be used with the base portion in use, and is formed so as to be removable from other portions except the base portion. May be. “Removable” includes a case where the base is a release sheet and can be removed by peeling, and a case where the base is an etchable material and can be removed by etching.

The material constituting the base is not particularly limited, and examples thereof include organic materials, inorganic materials, and composite materials using both.
The organic material is not particularly limited. For example, epoxy resin, BT (bismaleimide / triazine) resin, polyimide resin, phenol resin, xylene resin, thermosetting PPE (polyphenylene ether) resin, LCP ( Liquid crystal polymer), BCB (benzocyclobutene), polynorbornene and the like. These organic materials may be used alone or in combination of two or more. In addition, various rubbers and the like can be used in the base portion for the purpose of, for example, improving the strength.
Further, when an organic material is used, a glass cloth, a glass nonwoven fabric, a resin (polyamide, etc.) cloth, a resin (polyamide, etc.) nonwoven fabric, a resin (polyamide, etc.) film, PTFE (polytetrafluoro) as a core material inside the base portion. For example, a fluororesin-based core material and a metal foil having a three-dimensional network structure formed of ethylene may be used.

  The inorganic material is not particularly limited. For example, alumina, quartz, titania, zirconia, garnite, titanate (magnesium titanate, calcium titanate, strontium titanate, barium titanate etc.), mullite, cordierite, Examples thereof include ceramic materials such as stellite, wollastonite, anorthite, enstatite, diopsite, akermanite, gelenite, and spinel. Furthermore, crystalline or non-crystalline glass-based materials can be mentioned. Examples of the component constituting the glass material include Si, Al, Na, K, Mg, Ca, B, Pb, and Zn. Specific examples include aluminosilicate glass and aluminoborosilicate glass. These ceramic materials and glass materials may be used alone or in combination. When used in combination, a ceramic material can be contained in the glass material as a filler. These inorganic materials may be used alone or in combination of two or more.

  In particular, when a peelable release sheet is used, the release sheet is preferably an organic material. For example, polyester such as polyethylene terephthalate (PET), polyethylene, polypropylene, polyamide, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, Examples thereof include resin films and resin sheets such as polycarbonate, polystyrene, polyacrylonitrile copolymer, ethylene / vinyl acetate copolymer, and ethylene / vinyl alcohol copolymer.

Furthermore, the optical waveguide structure can include a conductor portion. The conductor portion is a portion having electrical conductivity and is usually patterned. By having this conductor part, both an optical signal and an electrical signal can be handled. Further, as will be described later, the optical waveguide device can further convert an optical signal and an electric signal by further including an optical element. Further, by providing the conductor portion in the optical waveguide structure, the connection distance between the optical element and the electronic component can be kept short, and the responsiveness can be improved. Furthermore, this contributes to miniaturization of the optical waveguide device itself using this optical waveguide structure.

The type of the conductor portion is not particularly limited, and examples thereof include normal wiring, through-hole conductors, via conductors, wiring patterns that function as resistors, wiring patterns that function as inductors, wiring patterns that function as capacitors, lands, and the like. There are no particular restrictions on the location of these conductors, but they can be placed in the cladding, the surface of the cladding, the base, or the like. Furthermore, the material which comprises a conductor part is not specifically limited, For example, gold | metal | money, silver, copper, platinum, nickel, chromium, titanium, aluminum, tungsten, molybdenum etc. can be used. These may use only 1 type and may use 2 or more types together.
The method for forming the conductor part is not particularly limited. For example, sputtering, ion plating, vapor deposition (including CVD and PVD), vapor deposition and plating, and patterning such as photolithography. Can be obtained in combination with the law.

The optical waveguide structure includes a peelable release sheet, a lower clad portion disposed on the release sheet, a core portion disposed on the lower clad portion and transmitting light, and the core portion on the core portion. An upper clad portion disposed; and an optical path converting portion that is disposed in the lower clad portion and converts an optical path of light propagating through the core portion,
The optical path changing portion is characterized in that a part of a previously formed optical path changing component is embedded in the uncured lower clad portion.
In other words, the waveguide structure has the same configuration as that provided with the release sheet as a base.

[2] The optical waveguide device optical waveguide device may comprise an optical waveguide structure, an optical element inside or outside surface of the optical waveguide structure.
The “optical element” is an element that can transmit and / or receive an optical signal, and is normally electrically operated. The optical element may be a light emitting element, a light receiving element, or a composite element thereof. Moreover, these light emitting elements may use only 1 type, and may use 2 or more types together.
The light emitting element is an element that can transmit an optical signal. Examples of the optical element include a surface emitting laser (VCSEL), a light emitting diode (LED), and a semiconductor laser diode (LD). These may use only 1 type and may use 2 or more types together.
The light receiving element is an element that can receive an optical signal. Examples of the light receiving element include a pin photodiode (pin PD) and an avalanche photodiode (APD). These may use only 1 type and may use 2 or more types together.
Furthermore, a composite element is an element in which these are integrated.

In addition to the optical element, the optical waveguide device can include other components. Examples of other components include electronic components. An electronic component is at least an electrically operated component. Examples of the electronic components include various active components (such as integrated circuit elements and transistors), passive components (such as capacitors, capacitors, and inductors), conversion components (such as filters and transformers), and connection components. These may use only 1 type and may use 2 or more types together.
A method for mounting these optical elements and electronic components is not particularly limited, and may be wire bonding and / or flip chip bonding.

[3] Method for Producing Optical Waveguide Structure The method for producing an optical waveguide structure of the present invention includes an uncured lower clad portion forming step for forming an uncured lower clad portion to be the lower clad portion, the optical path changing portion, an optical path changing component implantation step to implanted by partially sunk into uncured lower cladding portion of the optical path changing component which is preformed becomes, characterized in that it comprises a.

(1) Formation of Uncured Lower Cladding Portion The “uncured lower cladding portion forming step” is a step of forming an uncured lower cladding portion that becomes the lower cladding portion.
The “uncured lower clad portion” is a portion that is cured to become the lower clad portion. This uncured means that the polymerization is not completed. That is, the uncured state may be solid or liquid. Also, the presence or absence of viscosity is not particularly limited. However, it is soft enough to embed an optical path conversion component described later. This uncured state is a state in which it is dissolved in an organic solvent such as acetone. Further, the shape and the like of the uncured lower clad portion are not particularly limited, but are usually formed in layers. Further, the thickness is not particularly limited, but is usually 300 μm or less.

  Although the material which comprises this uncured layer is not specifically limited, Usually, it is a curable composition. The curable composition contains a curable compound that is cured to form the above-described cladding portion, and a photopolymerization initiator and / or a thermosetting initiator.

  Among these, as curable compounds, for example, epoxy compounds, acrylic compounds, fluorine compounds, imide compounds, bismaleimide compounds, phenylene compounds, phenylene ether compounds, phenol compounds, silicone compounds, urethane compounds Examples thereof include compounds, ester compounds, phenoxy compounds and olefin compounds. These compounds may use only 1 type and may use 2 or more types together. Among these, it is preferable that an acrylic compound and an epoxy compound are included. When this curable composition contains an epoxy compound, it is excellent in heat resistance, insulation, chemical resistance and water resistance, and when it contains an acrylic compound, it is excellent in photosensitivity and transparency.

The said epoxy-type compound says the compound which can superpose | polymerize by having an epoxy group. This epoxy compound is not particularly limited, and may be, for example, an oligomer, a monomer, or a mixture thereof. The monomer (in the oligomer, the monomer before oligomerization) and the oligomer may be bifunctional, polyfunctional, or a mixture thereof. Furthermore, as these monomers and oligomers, deuterates in which some or all of the hydrogen atoms are substituted with deuterium atoms can be used. In addition, a halide in which some or all of the hydrogen atoms are substituted with halogen atoms can be used. Furthermore, it may or may not have a silicone chain in the molecule.
Specifically, examples of the bifunctional epoxy compound include a glycidyl ether type, a glycidyl amine type, a glycidyl ester type, an alicyclic type (such as an epoxy compound having a cyclohexene oxide structure), and the like. Among these, examples of the glycidyl ether type include various bisphenol types, biphenyl types, naphthalene types, and fluorene types. Among these, examples of the bisphenol type include bisphenol A type, bisphenol F type, hydrogenated bisphenol type, bisphenol AF type, and bisphenol S type. Examples of the glycidylamine type include hydantoin type, aniline type, and toluidine type.
On the other hand, examples of the polyfunctional epoxy compound include glycidyl ether type and glycidyl amine type. Among these, examples of the glycidyl ether type include a phenol novolak type, a cresol novolak type, a diphenylpropane type, a trishydroxyphenylmethane type, and a tetraphenylolethane type. Examples of the glycidylamine type include aminophenol type, tetraglycidyldiaminidiphenylmethane type, triglycidyl isocyanurate type, and 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane type.
These glycidyl ether type epoxy compounds include monovalent aliphatic alcohols, polyhydric aliphatic alcohols, monovalent aromatic alcohols and polyvalent aromatic alcohols, glycidyl ether types derived from monohydric phenols and polyhydric phenols. Epoxy compounds are included. Examples of the aromatic ring constituting each aromatic alcohol include a benzene ring, a naphthalene ring, and an anthracene ring.
A compound in which some or all of the hydrogen atoms of each of these epoxy compounds are substituted with deuterium atoms and / or halogen atoms is exemplified.

  Examples of the acrylic compound include monovalent to polyvalent (meth) acrylate monomers and oligomers, compounds obtained by esterifying an alcohol with a carboxylic acid having an unsaturated bond such as acrylic acid or methacrylic acid, and derivatives thereof. It is done. Furthermore, the compound (for example, epoxy acrylate etc.) which added these acrylic compounds to the one part or all part epoxy group which an epoxy oligomer has is mentioned.

Examples of the photopolymerization initiator include a photo acid generator and a photo radical generator. These photopolymerization initiators are appropriately selected according to the type of the curable compound.
The photoacid generator refers to a compound capable of generating an acid upon irradiation with light and / or irradiation of light to a photosensitizer described later. Examples of the photoacid generator include an ionic acid generator and a nonionic acid generator. Examples of ionic acid generators include Lewis acid generators (various diazonium salts such as aryldiazonium salts), Bronsted acid generators {various onium salts (iodonium salts such as diaryliodonium salts, sulfonium salts such as diarylsulfonium salts, diaryls) Selenonium salts such as selenonium salts, sulfonium salts such as dialkylphenacylsulfonium salts, etc.)}. Examples of nonionic acid generators include sulfonic acid generators (such as sulfonic acid esters), carboxylic acid generators (such as carboxylic acid esters), and amide derivatives. These acid generators may be used alone or in combination of two or more. In addition, when the said sclerosing | hardenable compound contains an epoxy-type compound, it is preferable to use a photo-acid generator at least as a photoinitiator.

  The photo radical generator refers to a compound capable of generating radicals by light irradiation and / or a compound capable of generating radicals due to light irradiation to a photosensitizer described later. The photoradical generator is not particularly limited, and examples thereof include an organic boron complex, a carbonyl compound, an organic peroxide, an azo compound, an s-triazine compound, a hexaarylbiimidazole compound, and a titanocene compound. Of these, organoboron complexes, carbonyl compounds, and organic peroxides are particularly preferable. This radical generator may use only 1 type and may use 2 or more types together. In addition, when the said curable compound contains an acryl-type compound, it is preferable to use a photoradical generator at least as a photoinitiator.

  The mass ratio between the curable compound and the photopolymerization initiator (curable compound / photopolymerization initiator) is not particularly limited, but is preferably 100 / 0.05 to 100/10, more preferably 100. /0.1 to 100/5, more preferably 100 / 0.2 to 100/4. When this mass ratio is 100 / 0.05 to 100/10, the polymerization reaction sufficiently proceeds to obtain a lower clad portion that is superior in heat resistance, insulation, chemical resistance, and water resistance.

Furthermore, examples of the thermosetting initiator include a thermal acid generator and a thermal radical generator. These thermosetting initiators are appropriately selected according to the type of the curable compound. This thermosetting initiator can be completely cured by using it together with a photopolymerization initiator.
Examples of the thermal acid generator, an aromatic sulfonium salt compounds (as a counter anion, for example, SbF ₆ ^- and PF ₆ ^-, etc.), as thiophene compound salt (counter anion, for example, SbF ₆ ^- and PF ₆ ^- ), Pyridine-based compounds, soluble organic acids (eg, trifluoroacetic acid and paratoluenesulfonic acid), and Lewis acids (eg, boron trifluoride monoethylamine, boron trifluoride benzylamine, boron tetrafluoride) Acid salts, etc.). Specifically, SI-100L, SI-80L, SI-60L, SI-110L and SI-180L manufactured by Sanshin Chemical Co., Ltd., Adeka Opton CP-66 and CP-77 manufactured by Asahi Denka Co., Ltd., Nippon Soda CI-2639 and CI-2624 manufactured by Corporation, BSP (2-tribromomethylsulfonylpyridine), BMPS (α, α, α-tribromomethylphenylsulfone) manufactured by Sumitomo Seika Co., Ltd. and the like can be mentioned. In addition, when the said sclerosing | hardenable compound contains an epoxy-type compound, it is preferable to use a thermal acid generator at least as a thermosetting initiator.
Examples of the thermal radical generator include various organic peroxides (such as benzoyl peroxide). In addition, when the said sclerosing | hardenable compound contains an acryl-type compound, it is preferable to use a thermal radical generator at least as a thermosetting initiator.

  The mass ratio between the curable compound and the thermosetting initiator (curable compound / thermosetting initiator) is not particularly limited, but is preferably 100 / 0.05 to 100/10, more preferably 100. /0.1 to 100/5, more preferably 100 / 0.2 to 100/4. When this mass ratio is 100 / 0.05 to 100/10, the polymerization reaction by heating sufficiently proceeds to form a core portion with a more uniform cured state.

  Moreover, the said curable composition can be made to contain a photosensitizer according to the kind of light irradiated when making it harden | cure. The photosensitizer has a sensitizing action on the irradiated light and can assist the photopolymerization initiator. This photosensitizer is effective when it is difficult to obtain sufficient photosensitivity to the irradiated light with only a photopolymerization initiator or the like.

  Moreover, the formation method of this unhardened lower clad part is not specifically limited. For example, it can be formed using a film-shaped uncured lower clad portion formed in advance (hereinafter also referred to as “indirect formation”). That is, an uncured layer formed on the surface of a release sheet or the like can be peeled from the release sheet, and the uncured layer can be obtained by placing it on a predetermined site (on the surface of the base or the like when a base is provided). . As used herein, the film form is substantially non-fluid. “Substantially no fluidity” means that the formed molding state can be maintained. Specifically, the viscosity of the uncured film for forming a core part at a temperature of 20 ° C. is 10 Pa · s. What is above (more preferably 50 Pa · s or more, more preferably 200 Pa · s or more) is preferable. If it is this range, it will be excellent in the workability | operativity at the time of using as a film.

Further, it can be obtained by forming a layer composed of the curable composition by using various printing methods such as a doctor blade method, a spin coating method, a spray method, a curtain coating method, and a roll coating method (hereinafter simply referred to as “directly”). Also called "formation").
Of these indirect and direct formation methods, the indirect formation method is preferred. This is because workability and yield are good and mass productivity is excellent.

  When using the indirect forming method among the above, when using an uncured film for forming a lower clad part to be an uncured lower clad part, the uncured film for forming the lower clad part is pressure-bonded to a desired position. An uncured lower clad part can be obtained. The pressure-bonding conditions at the time of this pressure-bonding can be adjusted as appropriate, and are not particularly limited. For example, it is preferably performed by pressurizing at a temperature of 20 to 130 ° C. The temperature at this time is more preferably 40 to 100 ° C, and further preferably 50 to 80 ° C. The pressure during the pressurization is preferably 0.1 to 2.4 MPa, more preferably 0.3 to 1.0 MPa, and still more preferably 0.4 to 0.8 MPa. Moreover, it is preferable that pressurization time is 3 to 120 second, More preferably, it is 5 to 80 second, More preferably, it is 10 to 40 second. In addition, the film may be heated in advance when the pressure is applied.

  Furthermore, this pressure bonding may use a laminating method or a pressing method. The laminating method is a method of pressing a film by rolling a roll from one side to the other side. In the case of using this laminating method, it is possible to reduce the entrainment of bubbles because the pressure can be applied while extruding air. On the other hand, the pressing method is a method in which the entire film to be bonded (at least the entire film to be bonded, for example, the entire base portion) may be pressure-bonded using, for example, a rubber plate or a metal plate. Since the whole film can be pressurized simultaneously, it has excellent uniformity.

Further, the formation place of the uncured lower clad portion is not particularly limited. For example, an uncured lower clad portion can be formed on the base. That is, when an optical waveguide structure having a base (an optical waveguide structure having a base under the lower cladding) is to be obtained, the uncured lower cladding is formed on the base in the uncured lower cladding formation process. Can do. Further, even when an optical waveguide structure without a base is to be obtained, in the uncured lower clad portion forming step, the uncured lower clad portion is formed on the base, and then the base is removed. An optical waveguide structure that does not include a base can be obtained. The method for removing the base is not particularly limited, and for example, a method such as peeling and etching can be used.
Further, when the base portion is not used and an optical waveguide structure in which optical waveguide structures are stacked is obtained, an uncured lower clad portion can be formed on another optical waveguide structure.

  After the uncured lower clad portion forming step, an optical path conversion component embedding step described later is performed. However, another step may be provided between the uncured lower clad portion forming step and the optical path conversion component embedding step. That is, for example, when the uncured lower clad part is formed by the spin coat method, the uncured lower clad part after formation is usually in a liquid state. Therefore, it is possible to provide a step in which curing is advanced to some extent so that the optical path conversion component does not sink into the uncured lower clad portion due to its own weight. By providing this step, the optical path conversion component can be temporarily placed on the uncured lower clad part (or semi-cured lower clad part), and the optical path conversion component can be aligned. Furthermore, when the uncured lower clad portion is as described above, the optical path conversion component placing step is provided for aligning and temporarily placing the optical path changing component on the uncured lower clad portion. Can do.

(2) Placement of optical path conversion component The above "optical path conversion component embedding step" is a step performed after the uncured lower clad portion forming step, and a part of a pre-formed optical path conversion component to be an optical path conversion portion Is embedded in the uncured lower clad portion.
The “embedding” is to embed only a part of the optical path conversion component in the lower clad part, and the optical path conversion component is embedded in the lower layer (for example, the base or Other layers) may be embedded up to the surface, or may be embedded in a floating state in the uncured lower clad portion.

  Moreover, the embedding method is not particularly limited. That is, for example, pressurization or heating may be performed. Furthermore, you may perform both pressurization and a heating. Further, depending on the state of the uncured lower clad portion, these operations may be performed without causing the optical path changing component to sink naturally into the uncured lower clad portion. For example, when the uncured lower clad part is formed by spin coating, the optical path conversion component can be submerged in the uncured lower clad part only by its own weight.

The above pressurization usually imposes a pressure on the optical path conversion component, and the pressure is not particularly limited. For example, it is 2.4 MPa or less (particularly 1.0 MPa or less, and further 0.01 to 0.00). It can be performed by pressing at a pressure of 5 MPa).
The above heating is usually heating so that at least the uncured lower cladding is heated. For example, even if the temperature of the uncured lower cladding is indirectly increased by increasing the ambient temperature, Good. This is because the viscosity of the uncured lower clad portion is lowered by heating. Although the temperature at the time of this heating is not specifically limited, For example, the temperature of an unhardened lower clad part can be 30-120 degreeC (further 40-80 degreeC, especially 40-60 degreeC). In this heating, the optical path conversion component may be sunk only by heating, but pressurization may be performed simultaneously under the above pressurization conditions.

The present invention is characterized in that the optical path changing portion is formed after the uncured lower clad portion is formed. An optical waveguide structure that can change the optical path more accurately and prevents light leakage and scattering loss can be obtained.
That is, it is possible to prevent problems caused by the conventional method in which the uncured lower clad portion is unnecessarily adhered or deposited on the optical path changing portion. Therefore, the reflection surface angle shift due to unnecessary adhesion or deposition of the uncured lower clad material on the surface of the optical path conversion portion, light leakage due to this reflection angle shift, and optical signal scattering loss, etc. are extremely effective. Can be prevented. In addition, if the core portion is formed after the unnecessary adhesion or deposition, the core portion is easily formed even above the uppermost portion of the optical path conversion portion, and the core portion spans the optical path changing portion. It may be a form like this. For this reason, the light propagating in the core portion propagates to the rear of the optical path changing portion and causes light leakage. However, when the optical path changing portion is formed later as in the present invention, the above-mentioned unnecessary adhesion or deposition can be prevented, so that the uppermost portion of the optical path conversion component is flush with the upper surface of the core portion, or In addition, it is possible to obtain an optical waveguide structure that can be easily formed so that the uppermost portion of the optical path changing portion protrudes from the upper surface of the core portion, and light leakage and scattering loss are prevented from occurring. Furthermore, since an optical path changing part can be formed in the core part, there is no gap between the exit of the core part and the optical path changing part as in the conventional form. For this reason, scattering loss can be prevented very effectively.

  The process after the optical path conversion component embedding step is not particularly limited, and the uncured lower cladding portion may be cured after the optical path conversion component embedding step and proceed to the next step as a lower cladding portion, or semi-cured. Then, the process may proceed to the next process as a semi-cured lower clad part.

(3) Formation of core part and upper clad part In the manufacturing method of this invention, the process for forming a core part and an upper clad part are formed in addition to an uncured lower clad part formation process and an optical path conversion component embedding process. For the process. The process for forming the core part and the upper clad part is not particularly limited.
That is, for example, although a film body including a core portion and an upper clad portion formed in advance can be attached, it is usually formed by laminating an uncured core portion and an uncured upper clad portion. In this case, when the uncured core portion is formed, the uncured lower clad portion may remain in an uncured state, and is in a semi-cured state in which curing has progressed more than the uncured state. Alternatively, it may be cured to form a lower clad portion. Similarly, when forming the uncured upper clad portion, the uncured core portion may remain in an uncured state, may be in a semi-cured state, and is cured to form a core portion. May be.

The uncured state here means that the polymerization is not completed, and it may be solid or liquid. Also, the presence or absence of viscosity is not particularly limited. For example, it is soluble in an organic solvent such as acetone.
The semi-cured state means that the polymerization is not completed, but it is solid and not liquid. For example, when it is wiped with a cloth containing an organic solvent such as acetone, it is in a state where it is slightly scratched.
Further, the cured state means that the desired polymerization is completed, and is solid and not liquid. For example, it is insoluble in an organic solvent such as acetone, and is not damaged when wiped with a cloth containing such an organic solvent.

  Further, the process for forming the core and upper clad other than these is not particularly limited, but (i) semi-cured lower clad by semi-curing the uncured lower clad, and then semi-cured lower clad A core part is formed on the part, and then an uncured upper clad part is formed on the core part and the whole is collectively cured, or (ii) the uncured lower clad part is cured to form a lower clad, and thereafter A method of forming a core part on the lower clad part and then forming an upper clad part on the core part is preferable.

That is, in the method (i), in addition to the uncured lower clad portion forming step and the optical path conversion component embedding step,
Further, after the optical path conversion component embedding step, the uncured lower clad portion curing step for curing the uncured lower clad portion to obtain the lower clad,
A core part forming step of forming the core part after the uncured lower clad part hardening step;
And an upper clad portion forming step of forming an upper clad portion after the core portion forming step.
The method (i) may further include a core part forming uncured film disposing step of disposing a core part forming uncured film serving as a core part on the lower clad part in the core part forming step. it can.

In the method (i), the “uncured lower clad portion curing step” is a step of obtaining the lower clad by curing the uncured lower clad portion after the optical path conversion component embedding step.
The “core part forming step” is a step of forming the core part after the uncured lower clad part hardening step. That is, it is a process of forming on the lower clad part. In this step, an uncured film forming step for forming a core part that forms a film of the uncured core part that becomes the core part can be provided.
Further, the “upper clad portion forming step” is a step of forming the upper clad portion after the core portion forming step. That is, it is a process of forming on the core part.

The “core part forming step” in the method (i) is a step of forming a core part. This step usually includes an uncured core portion forming step and a patterning step of patterning and curing the uncured core portion to form a core portion.
Among these, in the uncured core part forming step, the material constituting the uncured core part is not particularly limited, but a curable composition that can be used as the uncured lower clad part can be applied as it is. However, since the material which comprises this uncured core part is normally patterned using photopolymerization, it contains the various components suitable for photopolymerization. That is, at least a photopolymerization initiator is contained, and a photosensitizer can be further contained.

The method for forming the uncured core part is not particularly limited. That is, it can be formed using a film-shaped uncured core portion formed in advance (hereinafter also referred to as “indirect formation”). That is, the uncured layer formed on the surface of the release sheet or the like can be peeled from the release sheet, and the uncured layer can be disposed at a predetermined site. As used herein, “film shape” in the uncured lower clad portion can be applied as it is.
Moreover, it can obtain by forming the layer which consists of a curable composition used as an unhardened core part using various printing methods, such as a doctor blade method, a spin coat method, a spray method, a curtain coat method, and a roll coat method ( Hereinafter, it is also simply referred to as “direct formation”).
Of these, indirect formation is preferred. This is because workability and yield are good and mass productivity is excellent.

  When using the method of indirect formation among the above, the uncured film for core part formation used as an uncured core part can be used. The method for disposing the uncured film for forming the core part in the disposing process for forming the uncured film for forming the core part for disposing the film is not particularly limited. The pressure-bonding conditions at the time of this pressure-bonding can be appropriately adjusted and are not particularly limited, but the pressure-bonding conditions can be applied as they are in the uncured film for forming the lower clad part. Similarly, a laminating method or a pressing method may be used.

  In the uncured film forming step for forming the core portion, the uppermost portion of the optical path changing portion is flush with the upper surface of the uncured film for forming the core portion, or the uppermost portion of the optical path changing portion is the core portion It is preferable to arrange so as to protrude from the upper surface of the uncured film. As a result, an optical waveguide structure in which the occurrence of light leakage and scattering loss is sufficiently suppressed can be obtained.

Moreover, the uncured film for forming a core part (that is, the uncured core part) disposed on the lower clad part is usually patterned by the patterning process as described above.
The patterning method is not particularly limited. For example, (1) a method by a photolithography method using predetermined light for an uncured layer, and (2) a predetermined light can be emitted from the surface side of the uncured layer. A method of irradiating a predetermined light using a light emitting means such as a light emitting element and selectively curing a portion irradiated and transmitted with light of an uncured layer (self-forming method), (3) irradiating a light laser It can be performed by a patterning method (laser drawing method) or the like. Among these, it is preferable to use a photolithography method. This is because the photolithography method has been conventionally used as a method for patterning a solder resist using a photosensitive resin, so that a commercially available apparatus can be used and can be produced at low cost.

  In this photolithography method, a desired pattern is exposed on an uncured layer using predetermined light (for example, ultraviolet rays, infrared rays, near infrared rays, etc.), and a desired portion of the curable composition is photocured. Refers to a method including a step of removing a portion that is not irradiated and remains uncured. More specifically, the patterning will be described. The uncured core portion is irradiated with light through a photomask having a predetermined pattern, and only the portion irradiated with light through the photomask pattern is cured. Thereafter, the uncured portion can be removed using a developer. At the time of exposure, a contact exposure method in which exposure is performed by bringing a mask into close contact with an uncured layer may be used, or a projection exposure method in which exposure is performed without bringing a mask into contact with an uncured layer may be used. However, when the surface of the uncured core part is a 1 cm wide polyethylene terephthalate film attached to the surface at room temperature and the polyethylene terephthalate film is peeled off at 90 mm in a direction of 50 mm / min, the peeling strength is 0.3 kN / m. In the following cases, the contact exposure method is preferably used.

  In addition, in this core part formation process, the hardening degree of the core part after complete | finishing all the processes of this invention may already be provided immediately after this core part formation process, but does not need to be provided. Usually, in the subsequent process, light irradiation and / or heating is performed to form other layers, etc., and as a result, the degree of cure of the core part formed in this process is often further improved. . Furthermore, a collective curing step described later can be provided as a final step.

The “upper clad portion forming step” is a step of forming an upper clad portion on the core portion and the lower clad portion.
A method for manufacturing the upper clad part is not particularly limited. Usually, an uncured upper clad part forming step for forming the uncured upper clad part, and an uncured upper clad part curing step for curing the uncured upper clad part, Is provided.
Among these, the formation of the uncured upper clad part may be performed by indirectly forming the uncured upper clad part or directly by the same method as the method for forming the uncured lower clad part. Of these, the method of indirect formation is preferred. This is because workability and yield are good and mass productivity is excellent. In the case of indirect formation, it is preferably performed by pressure bonding, and the condition can be applied as it is in the uncured lower clad portion. Furthermore, the lamination method may be used, and the press method may be used. Moreover, although the material which comprises an uncured upper clad part is not specifically limited, The material in the said uncured lower clad part can be applied as it is.

Furthermore, the uncured upper clad portion curing step can be performed in the same manner as the uncured lower clad portion curing step.
In this upper clad portion forming step, the degree of cure of the upper clad portion after completion of all the steps of the present invention may already be provided immediately after this upper clad portion forming step. Good. In other words, it is possible to further include a collective curing step described later as the final step.

On the other hand, in the method (ii), in addition to the uncured lower clad portion forming step and the optical path conversion component embedding step,
Further, after the optical path conversion component embedding step, the uncured lower clad part is semi-cured to form a semi-cured lower clad part by semi-curing the uncured lower clad part,
A core part forming step of forming a core part on the semi-cured lower clad part;
An uncured upper clad part forming step for forming an uncured upper clad part on the core part which becomes an upper clad part after the core part forming process;
And a collective curing step of collectively curing a laminate including a semi-cured lower clad portion, a core portion, and an uncured upper clad portion after the uncured upper clad portion forming step.
In the method (ii), a core part forming uncured film disposing step of disposing a core part forming uncured film as a core part on the uncured lower clad in the uncured core part forming step is further performed. Can be provided.

  The “uncured lower clad part semi-curing step” in the method (ii) is a step of obtaining a semi-cured lower clad by semi-curing the uncured lower clad part after the optical path conversion component embedding step. The core part forming process of the post process may be performed on the uncured lower clad part, but by providing the semi-cured process, it is possible to prevent the clad from being deformed in the subsequent process and to maintain flatness. Is preferable.

  The “core portion forming step” is a step of forming the core portion on the semi-cured lower clad portion. The core portion forming step is different in that the core portion is formed on the lower clad portion, whereas the core portion is formed on the semi-cured lower clad portion. About this other thing, the said core part formation process is applicable as it is.

  The “uncured upper clad portion forming step” is a step of forming an uncured upper clad portion that becomes an upper clad portion on the core portion after the core portion forming step. This step does not perform the uncured upper clad portion curing step of curing the uncured upper clad portion in the upper clad portion forming step in the method (i). The uncured upper clad portion formed in this step can be applied as it is in the method (i).

The “collective curing step” is a step of collectively curing a laminate including a semi-cured lower clad portion, a core portion, and an uncured upper clad portion after the uncured upper clad portion forming step.
By providing this collective curing step, the polymerization reaction of each part made of the curable composition (that is, at least the semi-cured lower clad part, the core part and the uncured upper clad part) proceeds sufficiently, and the cured state is more uniform. It can be set as a laminated body, and the reliability of the obtained optical waveguide structure can be improved. Furthermore, by providing this collective curing process, the influence on the optical waveguide structure due to thermal history such as soldering in the component mounting process when manufacturing the optical waveguide device using the optical waveguide structure (increased scattering loss, etc.) ) Can be suppressed.

  Although the heating conditions in this collective curing step are not particularly limited, for example, the heating temperature can be 70 to 240 ° C. (preferably 100 to 200 ° C., more preferably 120 to 180 ° C.). The heating time can be 10 to 180 minutes (preferably 20 to 120 minutes, more preferably 20 to 90 minutes). Furthermore, although a heating means is not specifically limited, For example, a thermostat, a ventilation dryer, etc. can be used.

Hereinafter, the present invention will be specifically described with reference to examples and drawings.
[1] Optical Waveguide Structure FIG. 1 is a diagram schematically showing a cross section of an example of an optical waveguide structure. Moreover, FIG. 2 is a figure which shows typically the AA cross section in FIG. The optical waveguide structure 100 includes a base (multilayer ceramic wiring substrate) 3, a lower clad part 21, a core part 1, an upper clad part 22, and optical path changing parts 41 and 42.

  The core unit 1 is optically path-converted by the optical path converters 41 and 42. Moreover, the core part 1 is comprised from the epoxy-type resin. On the other hand, the upper clad part 22 and the lower clad part 21 are made of an epoxy resin having a refractive index smaller than that of the core part 1.

  The base part (multilayer ceramic wiring board) 3 has conductor parts (not shown) such as via holes and through-holes for interlayer connection, and alumina-based sintered material, and these conductor parts are made of alumina-based sintered material. Insulated by binder. A lower cladding portion 21 and the like are provided on one surface side of the base portion 3, and a plurality of connection terminals (conductor portions 82) are provided on the other surface side. The conductor 82 is a connection terminal for mounting the optical waveguide structure 100 on a printed wiring board (not shown), and is made of gold, silver, copper, solder, aluminum, nickel, an alloy thereof, or the like.

  Further, the optical path conversion unit includes triangular optical path conversion units 41 and 42 made of gold and having inclined surfaces of about 45 ° facing each other. These optical path conversion units 41 and 42 are arranged on one surface of the base 3. Further, the uppermost portions of the optical path changing portions 41 and 42 are formed so as to be flush with the upper surface of the core portion 1 or protrude from the upper surface of the core portion 1.

[2] Optical Waveguide Device FIG. 3 is a diagram schematically showing a cross section of an example of the optical waveguide device. The optical waveguide device 200 includes the optical waveguide structure 100 described in [1] above. On the upper clad part 22 of the optical waveguide structure 100, a conductor part 81 for connecting the light emitting element 61 and the light receiving element 62 to an electric circuit (not shown) is provided as a conductor part. The conductor portion 81 is made of gold, silver, copper, solder, aluminum, nickel, an alloy thereof, or the like.

Further, the optical element includes a VCSEL that is the light emitting element 61 and a photodiode that is the light receiving element 62. The light emitting element 61 can emit predetermined light such as ultraviolet rays and near infrared rays, and the light receiving element 62 can detect these lights. The light emitting element 61 includes a light emitting portion, and is mounted with the light emitting portion facing downward. On the other hand, the light receiving element 62 includes a light receiving portion, and is mounted with the light receiving portion facing downward. Each optical element is bonded via a conductor portion 81 formed on the surface of the upper clad portion 22.
Each of these optical elements receives an electrical signal from an external circuit (not shown) and is converted into an optical signal by the light emitting element 61. Light emitted as an optical signal from the light emitting element 61 is transmitted through the core portion 1 to receive the light. Light is received at 62. The optical signal received by the light receiving element 62 is converted into an electric signal by the light receiving element 62 and transmitted to an external circuit (not shown).

[3] Manufacturing method 1 of optical waveguide structure (manufacturing method by sequential curing)
A method for manufacturing an example of the optical waveguide structure described in [1] will be described below.
(1) Base 3
As the base 3, a pre-sintered multilayer ceramic wiring board was prepared. The configuration of the multilayer ceramic wiring board is as described in [1] above.

(2) Formation of optical path conversion part pads and the like (step 1 in FIG. 6)
Attaching a dry film (plating resist) to one surface of the base 3 and protecting the area other than the pad formation by exposure and development with a dry film, followed by gold plating, and finally peeling off the dry film (plating resist) Thus, the optical path conversion unit pads 411 and 421 and the positioning reference pad 91 were formed. In addition, a transfer film in which a thin film made of gold that becomes the positioning reference pad 91 and the optical path conversion unit pads 411 and 421 for forming the optical path conversion unit is releasably held on the surface of the release sheet is prepared. It is also possible to transfer the transfer film to the surface of the multilayer ceramic wiring substrate.

(3) Uncured lower clad formation process (process 2 in FIG. 6)
Epoxy compound [alicyclic epoxy compound (manufactured by Daicel Chemical Industries, Ltd., product name “EHPE3150”) 99.5% by mass and polymerization initiator (acid generator, manufactured by Asahi Denka Kogyo Co., Ltd., product name “SP172”) 0 .5 mass%] is mixed with a solvent (methyl ethyl ketone) and dissolved to prepare a mixed solution (solid content: 78%), and then obtained. The mixed solution is coated on a release sheet (PET film, thickness: 38 μm) by a casting method (gap: 130 μm), and then dried by heating (conditions: 120 ° C. × 30 minutes) to remove the solvent. An uncured film for forming a clad part (uncured film for forming a lower clad part) thus obtained was prepared.
This uncured film for forming a cladding part is placed on the laminate obtained up to (2) above, and only the uncured film for forming a cladding part is pressure-bonded under the conditions of a temperature of 40 to 50 ° C. and a pressure of 0.5 MPa. did. Next, the film was dried under the conditions of a temperature of 120 ° C. for 30 minutes to form an uncured lower clad portion 21 ″.

(4) Optical path conversion component embedding process (process 3 in FIG. 6)
The optical path conversion parts 41 and 42 formed in advance are positioned so as to be accurately placed above the optical path conversion unit pads 411 and 421 based on the coordinates of the positioning reference 91 using the image means, and the uncured lower clad part Then, the resin is softened by heating to a temperature of 120 ° C., and the optical path conversion component sinks into the uncured lower cladding by its own weight. Embedded in.

(5) Curing of the uncured lower clad portion (step 4 in FIG. 6, step 4 in FIG. 7)
The laminate obtained up to the above (4) was exposed (exposure amount: 2000 mJ / cm ² , light source: ultraviolet lamp, exposure time: about 7 minutes). Next, heating is performed at 120 ° C. for 30 minutes as post-baking, and further curing is performed by heating at 150 ° C. for 1 hour as main curing to form the lower cladding portion 21, the base portion 3, the lower cladding portion 21, It was set as the laminated body provided with the optical path conversion parts 41 and 42. FIG.

(6) Core part formation process (process 5 of FIG. 7)
Epoxy compound [Aromatic epoxy compound (Japan Epoxy Resin Co., Ltd., product name “Epicoat 1001”) 44.5% by mass, alicyclic epoxy compound (Daicel Chemical Industries, Ltd., product name “EHPE3150”) 0 mass%] and a polymerization initiator (acid generator, manufactured by Asahi Denka Kogyo Co., Ltd., product name “SP172”) 0.5 mass% and a solvent (methyl ethyl ketone) are mixed and dissolved. A mixed solution (solid content: 78%) was prepared, and then the obtained mixed solution was coated on a support (PET film, thickness: 38 μm) by a casting method (gap: 130 μm), and then heated. Drying (conditions: 120 ° C. × 30 minutes) was performed, and an uncured film for core formation was obtained by removing the solvent.
This uncured film for forming the core part is placed on the lower clad part 21 and the optical path changing parts 41 and 42 of the laminate obtained up to the above (5), and the temperature is 40 to 50 ° C. and the pressure is 0.5 MPa. Under the conditions, only the uncured film for forming the core part was pressure-bonded onto the lower clad part 21 and dried under the condition of a temperature of 120 ° C. × 30 minutes to form an uncured core part 1 ″.
Next, a photomask on which a predetermined pattern (line width; about 50 μm) is formed is placed on the obtained uncured core portion, and exposure (exposure amount: 500 mJ / cm ² , light source: ultraviolet lamp, exposure time: about 2 minutes) and post-baked at a temperature of 120 ° C. for 30 minutes. Subsequently, development (30 seconds) was performed using 2-methoxyethanol, and washing with isopropyl alcohol (IPA) was performed. The uncured core portion was patterned and simultaneously semi-cured. Then, the core part 1 was formed by heating at 150 degreeC for 1 hour, and making it harden | cure.

(7) Upper clad formation process (process 6 in FIG. 7)
The same uncured film for forming a clad part (uncured film for forming an upper clad part) as used in (3) above was prepared.
Then, this uncured film for forming a clad part is placed on the core part 1 and the lower clad part 21 of the laminate obtained up to the above (6), and only the uncured film for forming a clad part is heated to a temperature of 40. Bonding was performed under the conditions of ˜50 ° C. and pressure of 0.5 MPa. Subsequently, it dried on the conditions of temperature 120 degreeC x 30 minutes, and formed the unhardened upper clad part (not shown).
Next, the obtained laminate was exposed (exposure amount: 2000 mJ / cm ² , light source: ultraviolet lamp, exposure time: about 7 minutes). Subsequently, it heated at 120 degreeC as a post-baking for 30 minutes, and also it heated and hardened at 150 degreeC for 1 hour as main hardening, the upper clad part 22 was formed, and the optical waveguide structure 100 was obtained.

[4] Manufacturing method 2 of optical waveguide structure (manufacturing method using batch curing process)
A method for manufacturing an example of the optical waveguide structure described in [1] will be described below.
(1) Optical path conversion component embedding process, etc. (process 1 to process 3 in FIG. 8)
In the same manner as in the above [3] (1) to (4), the optical path changing parts 41 and 42 were formed in the uncured lower clad part 21 ″.

(2) Uncured lower cladding part semi-curing step (step 7 in FIG. 8, step 7 in FIG. 9)
The laminate obtained up to the above (1) was exposed (exposure amount: 2000 mJ / cm ² , light source: ultraviolet lamp, exposure time: about 7 minutes). Subsequently, it was cured by heating at 120 ° C. for 30 minutes as a post bake, and the uncured lower clad part 21 ″ was semicured to form a semicured lower clad part 21 ′.

(3) Core part formation process (process 5 of FIG. 9)
In the same manner as in the above [3] (6), the core portion 1 was formed on the semi-cured lower clad portion 21 ′.

(4) Uncured upper clad portion forming step (step 8 in FIG. 9)
The same uncured film for forming a clad part (uncured film for forming an upper clad part) as that used in the above [3] (3) is prepared, and this uncured film for forming a clad part is similarly formed on the core part 1 And it mounted on the semi-hardened lower clad part 21 ', and it crimped | bonded only the uncured film for clad part formation on the conditions of the temperature of 40-50 degreeC, and the pressure of 0.5 MPa. Next, drying was performed under the condition of a temperature of 120 ° C. for 30 minutes to form an uncured upper clad portion 22 ″.

(5) Batch curing process (process 9 in FIG. 9)
The laminate obtained up to the above (4) was exposed (exposure amount: 2000 mJ / cm ² , light source: ultraviolet lamp, exposure time: about 7 minutes). Next, heating is performed at 120 ° C. for 30 minutes as post-baking, and further heating is performed at 150 ° C. for 1 hour as main curing, thereby further curing each of the semi-cured lower cladding portion 21 ′, the core portion 1 and the uncured upper cladding portion 22 ″. Thus, an optical waveguide structure 100 having each of the lower cladding part 21, the core part 1, and the upper cladding part 22 was obtained.

[5] Manufacturing Method of Optical Waveguide Device An exemplary manufacturing method of the optical waveguide device described in [2] will be described below.
(1) Formation of conductor portion 81 and positioning reference pad 92 (step 10 in FIG. 10)
A dry film (plating resist) is attached to the surface of the upper clad portion 22 of the optical waveguide structure 100 obtained in the above [3] and [4], and the surface other than forming a pad by exposure and development is protected with a dry film. After that, gold plating was performed, and finally the dry film (plating resist) was peeled off to form the conductor portion 81 and the positioning reference pad 92. In addition, a transfer film in which a thin film made of gold that becomes the conductor portion 81 and the positioning reference pad 92 is releasably held on the surface of the release sheet is prepared. It is also possible to transfer and form the transfer film on the surface of the upper clad portion 22 at a position determined based on the position.

(2) Mounting of the light emitting element 61 and the light receiving element 62 (step 11 in FIG. 10)
Based on the positioning reference 92 using the same image means as described above, the light emitting element 61 is accurately placed on the conductor portion 81 at the target position, and the conductor portion is formed by solder provided on one surface of the light emitting element 61 in advance. 81. Similarly, based on the positioning reference 92, the light receiving element 62 was mounted and similarly connected by soldering to obtain the optical waveguide device 200. The difference in refractive index (core portion-cladding portion) between the obtained core portion 1 and each of the clad portions 21 and 22 is 1.9% for 850 nm near-infrared light and 2 for the 589 nm Na-D line. 0.0%.

  The method for producing an optical waveguide structure according to the present invention can be widely used in the fields of optical communication, electric and electronics, and the like. For example, it can be used as an optical waveguide, an optical branching coupler, an optical multiplexer / demultiplexer, an optical isolator, an optical fiber amplifier, a wiring board, an IC package, and the like.

It is typical sectional drawing of an example of an optical waveguide structure. It is explanatory drawing which shows the AA cross section in FIG. 1 typically. It is a typical sectional view of an example of an optical waveguide device. It is explanatory drawing which shows typically the example of arrangement | positioning of an optical path change part. It is explanatory drawing which shows the other example of arrangement | positioning of an optical path changing part typically. It is explanatory drawing explaining an example of the manufacturing method of this optical waveguide structure. It is explanatory drawing explaining an example of the manufacturing method of this optical waveguide structure, Comprising: It is explanatory drawing explaining the process following FIG. It is explanatory drawing explaining the other example of the manufacturing method of this optical waveguide structure. It is explanatory drawing explaining the other example of the manufacturing method of this optical waveguide structure, Comprising: It is explanatory drawing explaining the process following FIG. It is explanatory drawing explaining an example of the manufacturing method of this optical waveguide device.

Explanation of symbols

  200; optical waveguide device, 100; optical waveguide structure, 1 "; uncured core portion, 1; core portion, 21"; uncured lower clad portion, 21 '; semi-cured lower clad portion, 21; lower clad portion, 22 "; uncured upper clad part, 22; upper clad part, 3; base part, 4, 41, 42; optical path changing part, 411, 421; pad for optical path changing part, 51; support, 52; surface protective film, 61; light emitting element, 62; light receiving element, 7; photomask, 81, 82; conductor part, 91, 92; positioning reference.

Claims (9)

A lower clad portion, a core portion disposed on the lower clad portion and transmitting light, an upper clad portion disposed on the core portion, and a portion disposed in the lower clad; and In an optical waveguide structure manufacturing method comprising: an optical path conversion unit that converts an optical path of light propagating through the core unit;
An uncured lower clad part forming step for forming an uncured lower clad part to be the lower clad part;
And an optical path conversion component embedding step for embedding a part of a previously formed optical path conversion component to be the optical path conversion portion into the uncured lower clad portion. Manufacturing method. The optical waveguide structure further includes a base below the lower cladding part,
2. The method of manufacturing an optical waveguide structure according to claim 1, wherein in the uncured lower clad portion forming step, the uncured lower clad portion is formed on the base.   The method of manufacturing an optical waveguide structure according to claim 2, wherein the uncured lower clad portion is formed by pressure bonding an uncured film for forming a lower clad portion to the base portion. Furthermore, after the optical path conversion component embedding step, the uncured lower clad part semi-curing step of semi-curing the uncured lower clad portion to form a semi-cured lower clad portion,
A core part forming step of forming the core part on the semi-cured lower clad part;
An uncured upper clad part forming step for forming an uncured upper clad part to be the upper clad part on the core part after the core part forming step;
The collective curing step of collectively curing the laminate including the semi-cured lower clad portion, the core portion, and the uncured upper clad portion after the uncured upper clad portion forming step. The manufacturing method of the optical waveguide structure in any one.   The manufacturing method of the optical waveguide structure of Claim 4 provided with the uncured film formation core part formation process which arrange | positions the uncured film for core part formation used as the said core part on the said semi-hardened lower clad part. . Further, after the optical path conversion component embedding step, the uncured lower clad portion curing step for curing the uncured lower clad portion to obtain a lower clad,
A core portion forming step for forming the core portion after the uncured lower clad portion hardening step;
The manufacturing method of the optical waveguide structure in any one of Claims 1 thru | or 3 provided with the upper clad part formation process which forms the said upper clad part after this core part formation process.   The optical waveguide structure according to claim 6, further comprising: an uncured film for forming a core part for disposing an uncured film for forming a core part on the lower clad part in the core part forming step. Body manufacturing method.   The optical waveguide according to any one of claims 1 to 7, wherein the optical path conversion component is made of metal, and is formed into a predetermined shape by pressing a supplied metal lump using a stamping jig. Manufacturing method of structure.   The method for manufacturing an optical waveguide structure according to any one of claims 1 to 8, wherein the embedding is performed by heating a temperature of the uncured lower clad portion to 30 to 120 ° C.

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