JP2017151295A - Method of manufacturing optical waveguide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an optical waveguide capable of reducing adverse effect to light for transmitting a core pattern by a bleed out component from a lower clad pattern and suppressing the reflection failure of an optical path conversion mirror by an environmental reliability test.SOLUTION: A method of manufacturing an optical waveguide includes: a step A of subjecting a lower clad pattern formation resin layer to pattern-exposure so as to be made as a lower clad pattern developed by an alkaline developer; and a step B of laminating a core pattern formation resin layer on the lower clad pattern, exposing a core pattern formation resin layer, and being made as a core pattern developed by the alkaline developer liquid. The step A includes a step A1 of impregnating a patterned cladding layer with bivalent or more metal ions.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing an optical waveguide.

  With the increase in information capacity, development of optical interconnection technology that uses optical signals not only for communication fields such as trunk lines and access systems but also for information processing in routers and servers is underway. In particular, as an optical transmission path for using light for short-distance signal transmission between boards in a router or a server device, optical fibers that have a higher degree of freedom in wiring and can be densified than optical fibers. It is desirable to use a waveguide. Among them, an optical waveguide using a polymer material excellent in processability and economy is promising.

  As one of methods for forming an optical waveguide simply and with high accuracy, a method for forming a pattern by exposure and development is known. Here, the exposure process is a step of insolubilizing the photosensitive resin in the light irradiation portion by three-dimensional crosslinking, and the development process is a step of dissolving and removing the photosensitive resin in the unexposed portion, that is, the unreacted portion in the developer. is there.

  A method of developing using an alkaline developer as a developer has been proposed (see, for example, Patent Documents 1 and 2). In order to make the optical waveguide forming material to which the alkali development process can be applied soluble in an alkaline developer, a functional group exhibiting acidity such as a carboxyl group and a phenolic hydroxyl group is introduced.

JP-A-6-258537 JP 2003-195079 A

  A core pattern made of a cured product of an alkali solution-soluble resin can be patterned with an alkali solution, and it is easy to ensure workability and safety.

  On the other hand, the core pattern made of a cured product of an alkali solution-soluble resin tends to be chemically unstable even when the core pattern is insolubilized by exposure to neutralize an acidic functional group with an alkaline developer to form a salt. And tends to be highly hydrophilic. Further, even if the core pattern is formed without development, the core pattern tends to be highly hydrophilic because it is a highly polar functional group.

Such an optical waveguide can improve the reliability (for example, moisture resistance) of the optical waveguide by protecting the core pattern with the lower clad layer and the upper clad layer. However, if the lower clad layer or the upper clad layer is made of a cured product of an alkali solution soluble resin like the core pattern, and the lower clad layer or the upper clad layer is patterned with an alkaline developer, the lower clad layer or the upper clad layer The cladding layer also tends to be highly hydrophilic as described above. In particular, the lower clad layer is a part that becomes a base of the core pattern and the upper clad layer, and is often exposed to an alkaline developer, and therefore tends to be more hydrophilic.
When such an optical waveguide is exposed to high-temperature and high-humidity conditions, the upper and lower clads of the core pattern absorb water, and the effect is likely to occur in the core pattern.

  In addition, when an optical waveguide with a mirror, in which an optical path conversion mirror is provided on such an optical waveguide, is exposed to high temperature and high humidity conditions, part of the constituent components of the lower cladding pattern is likely to bleed out (especially an inclined surface). When a bleed-out component occurs in the optical path conversion mirror consisting of the above, it remains as irregularities on the inclined surface, causing a problem of poor reflection and deterioration of characteristics.

  The present invention has been made in view of the above problems, and reduces the adverse effect on the light propagating through the core pattern due to the bleed-out component from the lower clad pattern, and suppresses the reflection failure of the optical path conversion mirror and the like. An object of the present invention is to provide an optical waveguide manufacturing method capable of reducing loss deterioration.

As a result of diligent research to solve the above problems, the present inventors have reduced the adverse effect on light propagating through the core pattern due to moisture absorption by impregnating the lower clad pattern with metal ions having a valence of 2 or more, and The present inventors have found that it is possible to suppress the reflection failure of the optical path conversion mirror due to the bleed-out component from the lower clad pattern, and to reduce the deterioration of the optical loss due to the environmental reliability test of the optical waveguide. The present invention has been completed based on such knowledge.
That is, the present invention relates to the following.
(1) Pattern exposure of the lower clad pattern forming resin layer, development with an alkaline developer to form a lower clad pattern, laminating a core pattern forming resin layer on the lower clad pattern, and forming the core pattern A process for producing an optical waveguide having at least a step B in which a resin layer is subjected to pattern exposure and developed with an alkaline developer to form a core pattern, wherein in the step A, a metal ion having a valence of 2 or more is formed on the lower clad pattern. The manufacturing method of the optical waveguide which has process A1 which impregnates.
(2) The method for manufacturing an optical waveguide according to (1), wherein the step A includes a step A2 of cleaning the lower clad pattern with an acidic solution after the step A1.
(3) The method for manufacturing an optical waveguide according to (1) or (2), which includes a step B1 of cleaning the core pattern with an acidic solution in the step B.
(4) The method for manufacturing an optical waveguide according to any one of (1) to (3), further including a step C of forming an optical path conversion mirror on the core pattern after the step B.
(5) After the step C, an upper clad pattern-forming resin layer is laminated so as to cover the upper surface and side surfaces of the core pattern, the upper clad pattern-forming resin layer is subjected to pattern exposure, and developed with an alkaline developer. The method for manufacturing an optical waveguide according to (4), further comprising a step D of forming an upper clad pattern and enclosing the optical path conversion mirror in an opening removed by development.
(6) The method for manufacturing an optical waveguide according to (5), wherein the step D includes a step D1 of impregnating the upper clad pattern with a metal ion having a valence of 2 or more.
(7) The method for producing an optical waveguide according to any one of (1) to (6), wherein the divalent or higher-valent metal ion is at least one of calcium ion and magnesium ion.
(8) The method for manufacturing an optical waveguide according to any one of (2) to (7), wherein the acidic solution is at least one of sulfuric acid and hydrochloric acid.
(9) At least one of the resin layer for forming a lower cladding pattern, the resin layer for forming a core pattern, and the resin layer for forming an upper cladding pattern is a resin composition containing a compound having a carboxyl group (1) The manufacturing method of the optical waveguide as described in any one of-(8).
(10) At least one of the lower clad pattern forming resin layer, the core pattern forming resin layer, and the upper clad pattern forming resin layer is (A) a carboxyl group-containing alkali-soluble polymer, and (B) polymerizable. The method for producing an optical waveguide according to (9), which is a resin composition comprising a compound and (C) a photopolymerization initiator.

  Even if the optical waveguide obtained by the optical waveguide manufacturing method of the present invention is an optical waveguide having an alkali-soluble lower clad pattern and core pattern, it is possible to reduce the adverse effect on light propagating through the core pattern due to moisture absorption. . In addition, even when an optical path conversion mirror is formed in the core pattern, it is possible to suppress poor reflection of the optical path conversion mirror due to a bleed-out component from the lower clad pattern, thereby reducing optical loss deterioration due to the environmental reliability test of the optical waveguide. An optical waveguide with a mirror can be obtained.

It is a perspective view which shows the optical waveguide obtained by one Embodiment of the manufacturing method of the optical waveguide of this invention.

FIG. 1 shows an optical waveguide obtained by an embodiment of the method for manufacturing an optical waveguide of the present invention. An optical waveguide to which an embodiment of an optical waveguide manufacturing method of the present invention is applied has an optical waveguide having at least a core pattern 2 developed with an alkaline developer on a lower clad pattern 1 developed with an alkaline developer. As shown in FIG. 1, it may be an optical waveguide provided with an upper clad layer (or upper clad pattern) so as to embed the core pattern 2 or an optical waveguide with a mirror having an optical path conversion mirror 4 as shown in FIG. .
By using the lower clad pattern 1, the optical waveguide can be processed into an arbitrary shape by a development process. For example, when the optical waveguide is fitted to an external housing or formed on an electric wiring board as described later, various parts are used. It is used as an optical waveguide that can be mounted (for example, an optical element, a radiator, an external housing, etc.).
Hereinafter, the manufacturing method of the optical waveguide of the present invention will be described in detail.

[Step A]
In one embodiment of the method for producing an optical waveguide of the present invention, first, the lower clad pattern forming resin layer is subjected to pattern exposure and developed with an alkaline developer to form the lower clad pattern 1.

[Step B]
Next, a step B of laminating a core pattern forming resin layer on the lower clad pattern 1 formed in the step A, pattern exposing the core pattern forming resin layer, and developing with an alkaline developer to form the core pattern 2 is performed. Have.

  When the resin layer for forming the lower cladding pattern and the resin layer for forming the core pattern are soluble in the alkaline developer as in the optical waveguide manufacturing method of the present embodiment, the lower cladding pattern developed by the alkaline developer 1 includes ions contained in the alkaline developer in the lower clad pattern 1. In particular, when the ion is a monovalent cation, the monovalent cation forms a salt with an alkali-soluble acidic functional group contained in the lower clad pattern 1 and easily absorbs moisture. In particular, in the case where the core pattern 2 is also patterned with an alkaline developer, the core pattern 2 is easily affected by light absorption due to moisture absorption from the lower clad pattern 1 side. Since the moisture absorption of the core pattern 2 through the lower cladding pattern 1 also occurs, the optical characteristics are more easily affected.

[Step A1]
Therefore, in the optical waveguide manufacturing method of the present embodiment, in step A, as the step A1, the lower clad pattern 1 is impregnated with bivalent or higher metal ions. Thereby, the moisture absorption resistance of the lower clad pattern 1 is improved, and the deterioration of optical characteristics due to moisture absorption of the core pattern 2 adjacent to the lower clad pattern 1 can be suppressed. In particular, the step A1 is preferably performed before the step B because the lower clad pattern 1 in the vicinity of the interface between the lower clad pattern 1 and the core pattern 2 can be impregnated with metal ions having a valence of 2 or more.

In step A1, the alkaline developer may contain a divalent or higher valent metal ion. However, if an alkaline developer containing a divalent or higher valent metal ion is used, there is a concern that a development residue may occur. It is preferable that the lower clad pattern 1 is impregnated with a divalent or higher valent metal ion using a solution containing a divalent or higher valent metal ion after development with an alkaline developer containing the cation. There are no particular limitations on the method for impregnating the divalent or higher metal ions, but from the viewpoint of impregnating the surface and side surfaces of the lower cladding pattern 1 from the viewpoint of easy substitution with monovalent cations, divalent or higher metal ions are included. A method of immersing the lower clad pattern 1 in a solution is suitable.
The step A1 may be performed after the lower cladding pattern 1 is formed and then photocured or thermally cured on the lower cladding pattern 1, but from the viewpoint of efficient substitution with monovalent cations. It is preferably performed before photocuring or heat curing.
A cleaning process using a solvent or water (for example, pure water or ultrapure water) may be provided between the development of the lower clad layer and the process A1.

[Step A2]
In the present embodiment, the process A includes a process A2 of cleaning the lower clad pattern with an acidic solution after the process A1.

  By washing with an acidic solution after step A1, excess divalent or higher metal ions remaining on the surface of the lower cladding pattern 1 can be removed. Excess divalent or higher metal ions that form salts can also be removed by liberation of weak acids. Thus, by removing excessive divalent or higher metal ions, the influence on the core pattern 2 formed on the lower cladding pattern 1 can be reduced, and deterioration of optical characteristics can be suppressed.

  As another effect, the adhesion between the lower clad pattern 1 and the core pattern 2 can be improved. This is because the alkali-soluble acidic functional group contained in the lower clad pattern 1 has a high polarity and contributes to chemical adhesion with the core pattern 2. However, when the alkali-soluble acidic functional group of the lower cladding pattern 1 and a metal ion having a valence of 2 or more form a salt, the chemical adhesion is inhibited, and the core pattern 2 is peeled off when the core pattern 2 is developed. May occur. For this reason, the adhesion with the core pattern 2 is achieved by cleaning with an acidic solution, dissolving the salt with a divalent or higher-valent metal ion only in the vicinity of the surface of the lower clad pattern, and using the original alkali-soluble acidic functional group. improves.

Further, even when the core pattern 2 is not peeled off during development, when the optical path conversion mirror 4 is provided directly on the core pattern 2 using cutting or the like as described later, the optical path is generated by the force generated during the processing. There is a possibility that peeling between the lower cladding pattern 1 and the core pattern 2 in the vicinity of the conversion mirror 4 occurs. When such peeling between the lower clad pattern 1 and the core pattern 2 occurs, the light loss in the optical path conversion mirror 4 deteriorates. Furthermore, if the core pattern 2 falls off during processing, the optical path change itself becomes impossible.
Further, when a resin film for forming an upper clad pattern is formed by pressurizing and laminating a resin film for forming an upper clad pattern as will be described later, the lower clad pattern 1 and the core pattern 2 may also be peeled off due to the flow of the resin. There is. Such peeling appears as meandering of the core pattern 2, and in this case, light cannot be propagated satisfactorily in the core pattern 2, so that the optical characteristics are deteriorated.
That is, the effect of suppressing the peeling of the core pattern 2 is obtained in the step in which physical force acts on the core pattern 2 after the core pattern 2 is formed by including the step A2.
The effect of suppressing the peeling of the core pattern 2 by physical force is that chemical bonding (for example, hydrogen bonding) between the lower cladding pattern 1 and the core pattern 2 is performed when heat treatment (or heat curing may be performed) after the core pattern 2 is formed. And adhesion by cross-linking by covalent bond) can be further improved.

  When the resin layer for forming the lower cladding pattern is developed and then washed with an acidic solution without impregnating metal ions having a valence of 2 or more, monovalent cations contained in the alkaline developer attached to the lower cladding pattern 1 However, the removal of the monovalent cation by the acidic solution occurs predominantly near the surface layer of the lower cladding pattern 1, and the monovalent cation tends to remain inside the lower cladding pattern 1. For this reason, there is a concern about a decrease in moisture resistance due to bleed-out from the lower clad pattern 1 or the like.

  Bivalent or higher metal ions are efficiently replaced because the ion exchange with the monovalent cations in the lower cladding pattern 1 is performed. Thereafter, when cleaning with the acidic solution in step A2 is performed, metal ions having a valence of 2 or more are removed. However, the removal mainly occurs in the vicinity of the surface layer of the lower cladding pattern 1. If it does so, since it will be in the state which impregnated the metal ion more than bivalence in the inside of the lower clad pattern 1, improvement in moisture resistance can be aimed at. In addition, the process which has process A2 after such process A1 is applicable not only to the manufacturing method of an optical waveguide but to the manufacturing method of the resin laminated body which laminates | stacks the patterned alkali-soluble resin sequentially.

From the above, the process A2 is preferably performed after the process A1. The lower clad pattern 1 may be photocured or thermally cured between the steps A1 and A2, but the step A2 is preferably performed before the photocuring or thermosetting.
Note that a cleaning step with a solvent or water (for example, pure water or ultrapure water) or the like is provided between the step A1 and the step A2, so that generation of insoluble salts can be reduced.

[Step B1]
In the present embodiment, the process B includes a process B1 in which the core pattern 2 is washed with an acidic solution.

  The core pattern 2 developed by the alkaline developer contains ions contained in the alkaline developer in the surface layer of the core pattern 2 in the same manner as the lower clad pattern 1 described above. In particular, if the ion is a monovalent cation, the monovalent cation forms a salt with an alkali-soluble acidic functional group contained in the core pattern 2, thereby reducing the initial optical characteristics and moisture absorption resistance. May cause. Accordingly, when the core pattern 2 is washed with an acidic solution as the step B1, monovalent cations in the core pattern 2 can be reduced, so that deterioration of initial optical characteristics and moisture absorption resistance can be suppressed.

  Further, the step B1 has an effect of removing again ions contained in the alkaline developer when the core pattern 2 reattached to the lower clad pattern 1 exposed from the core pattern 2 is developed. Due to this effect, the moisture resistance of the lower cladding pattern 1 is further improved.

  Further, the excess divalent or higher metal ions remaining on the surface layer of the lower clad pattern 1 in the step A1 can be removed by the step B1. Accordingly, the chemical adhesive force between the lower clad pattern 1 and the upper clad pattern 3 (or the upper clad layer) can be improved for the same reason as that for improving the adhesive force with the core pattern 2 described above. In particular, the above-mentioned chemical adhesive force is more effective when both the lower clad pattern forming resin and the upper clad pattern forming resin are alkaline developer-soluble resins.

[Step C]
In this embodiment, after the process B, it is preferable to have a process C for forming the optical path conversion mirror 4 on the core pattern 2. The optical path conversion mirror 4 can be formed by providing an inclined surface directly on the core pattern 2. At this time, it is preferable that the inclined surface has a depth reaching the lower cladding pattern 1 because an inclined surface having a predetermined angle can be formed on the core pattern 2.

  In particular, when the core pattern 2 is soluble in an alkaline solution, the bleed-out component is easily added to the optical path conversion mirror 4 because the bleed-out component (part of the component of the lower cladding pattern 1) has high affinity. It will move. As described above, when the lower clad pattern 1 is impregnated with metal ions having a valence of 2 or more, bleeding out from the lower clad pattern 1 can be suppressed, so that the reliability of the optical path conversion mirror 4 can be improved.

  Further, since the adhesion between the lower clad pattern 1 and the core pattern 2 can be improved by performing the step A2 (the step of washing the lower clad pattern with an acidic solution), the core pattern 2 as in the step C. On the other hand, even in a processing method in which the core pattern 2 is easily peeled off, such as forming the optical path conversion mirror 4 directly, the peeling is suppressed.

[Step D]
In this embodiment, after step C, an upper clad pattern forming resin layer is laminated so as to cover the upper surface and side surfaces of the core pattern 2, and the upper clad pattern forming resin layer is subjected to pattern exposure and developed with an alkaline developer. Then, the upper clad pattern 3 is formed, and it is preferable to include a step D of enclosing the optical path conversion mirror 4 in the opening 5 removed by development. Thereby, the optical path conversion mirror 4 can be functioned as the air reflection type optical path conversion mirror 4.
In the present embodiment, an optical waveguide having the optical path conversion mirror 4 is illustrated. However, when there is no need to pattern the optical waveguide without the optical path conversion mirror 4 or the upper cladding layer, the upper cladding pattern An unpatterned upper clad layer may be formed using a resin layer similar to the forming resin layer.

  If the optical path conversion mirror 4 is an air reflection type optical path conversion mirror 4, for example, when a bleed-out from the lower cladding pattern 1 adheres to the optical path conversion mirror 4, the bleed-out component tends to be uneven on the optical path conversion mirror surface. Therefore, good optical path conversion cannot be performed. However, as described above, the highly reliable optical path conversion mirror 4 can be formed by impregnating the lower clad pattern 1 with metal ions having a valence of 2 or more to suppress bleed-out and by the process D.

  As described above, the lower clad pattern 1 is washed with the acidic solution in the step A2 or the step B1, so that the adhesion between the core pattern 2 and the upper clad pattern 3 (or the upper clad layer) or the lower clad pattern 1 is obtained. It becomes easy to ensure the adhesiveness between the upper cladding pattern 3 (or the upper cladding layer) and the effect of suppressing the peeling of each interface due to the development of the upper cladding pattern 3 is obtained.

[Step D1]
The step D may further include a step D1 in which the upper cladding pattern 3 is impregnated with metal ions having a valence of 2 or more.

Step D1 may be performed after the development of the upper clad pattern forming resin layer. The alkaline developer used for developing the resin layer for forming the upper clad pattern may contain a metal ion having a valence of 2 or more. However, if an alkaline developer containing a metal ion having a valence of 2 or more is used, a development residue tends to occur. Preferably, after development containing monovalent cations, the upper clad pattern is impregnated with divalent or higher metal ions using a solution containing divalent or higher metal ions. There are no particular limitations on the method for impregnating divalent or higher metal ions, but from the viewpoint of impregnating the surface and side surfaces of the upper cladding pattern 3 from the viewpoint of easy substitution with monovalent cations, divalent or higher metal ions are included. A method of immersing the upper cladding pattern 3 in a solution is suitable.
Further, the step D1 may be performed after the upper cladding pattern 3 is formed and then photocured or thermally cured on the upper cladding pattern 3, but from the viewpoint of efficient substitution with monovalent cations. It is preferable to carry out before photocuring or heat curing.
A washing step or the like may be provided between the development of the upper clad pattern forming resin layer and the step D1.

By having the step D1, alkaline development at the time of developing the upper clad pattern forming resin layer reattached to the lower clad pattern 1 exposed in the optical path conversion mirror 4 or the opening 5 by developing the upper clad pattern forming resin layer Cations contained in the liquid can be removed, and improvement in reliability can be expected.
Further, since the wall surface in the opening 5 can be impregnated with metal ions having a valence of 2 or more, bleeding out from the side surface of the upper cladding pattern 3 can be suppressed. Furthermore, since the optical path conversion mirror 4 provided in the core pattern 2 can be impregnated with metal ions having a valence of 2 or more, bleeding out from the optical path conversion mirror 4 can be suppressed. In other words, since all the surfaces such as the bottom surface, the side surface, and the inclined surface in the opening 5 are impregnated with metal ions having a valence of 2 or more, it is possible to contribute to improvement in reliability.

  Moreover, since the metal ion containing layer more than bivalence can be provided in the upper and lower sides of the core pattern 2 by having process D1, the moisture absorption resistance from the up-down direction of an optical waveguide can be improved.

  In addition, after the step D1, cleaning is performed for the purpose of removing a certain amount of metal ions having a valence of 2 or more that are excessively attached to or contained in the bottom surface, side surface, inclined surface, and surface layer of the upper cladding pattern 3 in the opening 5. Also good. Washing with water or acidic solution is preferred. The acidic solution may be the same solution as step A2 or a different solution.

If the lower clad pattern forming resin layer, the core pattern forming resin layer, and the upper clad pattern forming resin layer (hereinafter abbreviated as each pattern forming resin layer) are made of a photosensitive resin layer, pattern exposure is performed. After forming a hardened part and an unhardened part, it can be set as each pattern by removing this unhardened part with the above-mentioned alkaline developing solution.
The exposure method is not particularly limited, and contact exposure, proxy exposure, stepper exposure, etc. that draw a pattern through a film-like or plate-like glass mask, direct drawing method that directly draws using laser light, etc. are used. . The wavelength used for exposure is not particularly limited, and ultraviolet light, visible light, and infrared light are preferably used, but ultraviolet light is preferable.
Hereinafter, a method for forming each pattern forming resin layer will be described in detail.

[Method for forming each pattern forming resin layer]
The method for forming the lower clad pattern forming resin layer, the core pattern forming resin layer, and the upper clad pattern forming resin layer is not particularly limited, but spin coating using each pattern forming resin composition described later, Examples thereof include a method of applying each pattern forming resin layer by dip coating, spraying, bar coating, roll coating, curtain coating, gravure coating, screen coating, ink jet coating, or the like.

As another method for forming each pattern, there is a method of using each pattern forming resin film made of each pattern forming resin composition to form each pattern forming resin layer by a laminating method. Each pattern forming resin film preferably has a three-layer structure in which each pattern forming resin composition is applied on a support film and a protective film is laminated thereon, as will be described in detail later. Used for.
From the viewpoint that an optical waveguide manufacturing process with excellent productivity can be provided, and from the viewpoint that the smoothness of the surface layer of each pattern-forming resin film can be easily kept constant, the above-described pattern-forming resin films are used to form a laminate. The manufacturing method is preferred.
As a laminating method using each pattern forming resin film comprising each pattern forming resin composition, after peeling off and removing the protective film, an atmospheric pressure roll laminator, a vacuum roll laminator, an atmospheric pressure flat plate laminator, a vacuum flat plate laminator, etc. A method for forming each pattern-forming resin layer by using it is preferable.
Hereinafter, each member used for the optical waveguide of the present invention will be described in detail.

[Core pattern]
The core pattern 2 of the present embodiment is made of a cured product of an alkali solution-soluble resin, and the refractive index after curing is higher than the refractive index of the lower cladding pattern 1 or the upper cladding pattern 3 (or the upper cladding layer). It is adjusted to become. It should be transparent as long as it does not interfere with the propagating light.
Since the core pattern 2 is patterned with an alkaline developer as described above, the core pattern 2 is preferably formed from a core pattern forming resin layer made of a photosensitive resin capable of forming a cured portion and an uncured portion by exposure.
The shape of the core pattern 2 is not particularly limited, and may be a straight line, a curve, a branch, or a composite shape thereof when viewed from the normal direction with respect to the surface of the lower cladding pattern 1. The cross-sectional shape is preferably a rectangle which is a general shape when formed by photolithography.
The thickness of the core pattern 2 can be appropriately selected according to the size of the light source incident on the core pattern 2 and the size of the light receiving element that receives the light output from the core pattern 2, but is preferably 8 to 100 μm, and is preferably 20 to 75 μm. It is better if it is 25-50 μm.

[Optical path conversion mirror]
The optical path conversion mirror 4 of the present embodiment is composed of an inclined surface directly formed on the core pattern 2. The angle formed between the inclined surface and the upper surface of the lower clad pattern 1 can be appropriately selected depending on the angle to be changed in the optical path, but is preferably 20 ° to 70 ° or 110 ° to 160 °, and 35 ° to 55 ° or 125 ° to 145 ° is better, and 40 ° to 50 ° or 130 ° to 140 ° is even more preferable.
The method for forming the optical path conversion mirror 4 is not particularly limited, but can be formed by laser ablation or physical cutting using a dicing blade after the core pattern 2 is formed. At this time, it is good also as an inclined surface connected to below the surface layer of the lower cladding pattern 1. FIG. By connecting, an inclined surface having a desired angle can be reliably formed on the core pattern 2.
Although not described in the present embodiment, a reflective metal layer may be provided on the formed inclined surface to form a metal reflection type optical path conversion mirror 4.

[Lower cladding pattern]
The lower clad pattern 1 of the present embodiment is a cured resin obtained by patterning a resin layer for forming a lower clad pattern with an alkaline developer, and serves as a base on which the core pattern 2 is formed. Since the lower clad pattern 1 is patterned with an alkaline developer as described above, the lower clad pattern 1 is preferably formed from a lower clad pattern forming resin layer made of a photosensitive resin capable of forming a cured portion and an uncured portion by exposure. .
The lower cladding pattern 1 is also a part that protects the lower surface of the core pattern 2. It is preferable that the refractive index of the core pattern 2 is adjusted to be lower than that of the core pattern 2 so that the light propagating through the core pattern 2 has no hindrance.
From the viewpoint of protecting the core pattern 2 and not adversely affecting the propagation of light, the lower clad pattern is preferably 5 to 200 μm thick, and from the viewpoint of thickness control, 10 to 100 μm is better and low profile. From the viewpoint of chemical conversion, the thickness is further preferably 10 to 50 μm.

[Upper clad pattern]
The upper clad pattern 3 of the present embodiment is a part that covers the upper surface and the side surface of the core pattern 2, and is a part that protects the upper surface and the side surface of the core pattern 2. It is preferable that the refractive index of the core pattern 2 is adjusted to be lower than that of the core pattern 2 so that the light propagating through the core pattern 2 has no hindrance. Since the upper clad pattern 3 is patterned with an alkaline developer as described above, it is preferably formed from an upper clad pattern forming resin layer made of a photosensitive resin capable of forming a cured portion and an uncured portion by exposure.

  The thickness of the upper clad pattern 3 is not particularly limited, but is preferably 5 to 100 μm from the upper surface of the core pattern 2, more preferably 10 to 75 μm from the viewpoint of thickness control, and 10 to 10 from the viewpoint of reducing the height. More preferably, it is 50 μm.

  The opening 5 formed by patterning the resin layer for forming the upper clad pattern only needs to include at least the optical path conversion mirror 4 provided in the core pattern 2. Further, it is better that the upper surface and side surfaces of the core pattern 2 connected to the inclined surface of the optical path conversion mirror 4 and a part of the surface of the lower cladding pattern 1 are included in the opening 5.

In the method of manufacturing an optical waveguide according to the present embodiment, since the lower clad pattern forming resin layer is patterned, it is preferable to form the optical waveguide on the substrate from the viewpoint of improving the handling property during the manufacturing. The substrate is not particularly limited, but a silicon substrate, glass substrate, glass epoxy resin substrate, plastic substrate, metal substrate, substrate with resin layer, substrate with metal layer, plastic film, plastic film with resin layer, plastic with metal layer A film, an electrical wiring board, etc. are mentioned.
The substrate may be peeled off after the optical waveguide is formed. However, when the substrate is used as an optical waveguide with a substrate, rigidity can be imparted to the optical waveguide by using a rigid substrate. Flexibility can be imparted to the waveguide.
When a portion where the lower clad pattern 1, the core pattern 2, and the upper clad pattern 3 are not provided is provided, various components (for example, an optical element, a radiator, and an external housing) are mounted on the same level as the optical waveguide on the substrate. be able to. In particular, when an electric wiring board is used as a substrate and an optical waveguide is formed so that at least the electric wiring is exposed, the exposed electric wiring can be used as a terminal of an optical element or the like.
Hereinafter, each solution used in the present embodiment will be described in detail.

[Alkaline developer]
In the present embodiment, the alkaline developer for forming the lower cladding pattern 1, the core pattern 2, and the upper cladding pattern 3 is not particularly limited, and a basic organic solvent, an aqueous solution, or a mixed solution thereof is used. The base of the alkaline aqueous solution is not particularly limited, but alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate; lithium hydrogen carbonate Alkali metal bicarbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate (alkali metal hydrogen carbonates); alkali metal phosphates such as potassium phosphate and sodium phosphate; alkali metals such as sodium pyrophosphate and potassium pyrophosphate Pyrophosphates; sodium salts such as sodium tetraborate and sodium metasilicate; ammonium salts such as ammonium carbonate and ammonium hydrogen carbonate; tetramethylammonium hydroxide, triethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethy 1,3-propanediol, and organic bases such as 1,3-diamino-propanol-2-morpholine.
An alkaline developer containing a monovalent cation is preferable because a development residue hardly occurs during development.

  The method for developing the lower clad pattern forming resin, the core pattern forming resin, and the upper clad pattern forming resin is not particularly limited, but is a spray method, a dipping method, a paddle method, a spin method, a brushing method, a scraping method. Etc. Moreover, you may use these methods together as needed.

These bases of the alkaline aqueous solution can be used alone or in combination of two or more.
The pH of the alkaline aqueous solution used for development is preferably 9 to 14, more preferably 10 to 13. The temperature of the alkaline aqueous solution used for development is adjusted according to the developability of each pattern forming resin layer. Moreover, you may mix surfactant, an antifoamer, etc. in alkaline aqueous solution.

  Moreover, there is no problem even if the alkaline developer is an alkaline quasi-aqueous developer composed of an alkaline aqueous solution and one or more organic solvents. The pH of the alkaline quasi-aqueous developer is preferably as small as possible within a range where development can be sufficiently performed, preferably pH 8 to 13, and more preferably pH 9 to 12.

  The organic solvent is not particularly limited, but alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol, and diethylene glycol; ketones such as acetone, methyl ethyl ketone, and 4-hydroxy-4-methyl-2-pentanone; ethylene Examples thereof include polyhydric alcohol alkyl ethers such as glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

These organic solvents can be used alone or in combination of two or more. Moreover, it is preferable that the density | concentration of an organic solvent is 2 to 90 mass% normally, and the temperature of alkaline semi-aqueous developing solution is adjusted according to the developability of each resin layer for pattern formation.
Further, a small amount of a surfactant, an antifoaming agent or the like may be mixed in the alkaline quasi-aqueous developer.

[Divalent or higher metal ions]
There are no particular limitations on the type of divalent or higher-valent metal ions used in this embodiment, and magnesium ions, calcium ions, zinc ions, manganese (II) ions, cobalt (II) ions, iron (II) ions, copper (II) ions, iron (III) ions, aluminum ions and the like.
In particular, when a solution containing divalent or higher valent metal ions is used, the exposed surface of the lower cladding pattern 1 and the exposed surface of the upper cladding pattern 3 can be easily impregnated, and the effect on the optical loss is relatively small. Therefore, divalent metal ions are preferable, and magnesium ions (Mg ²⁺ ) and calcium ions (Ca ²⁺ ) are more preferable.
These metal ions can be used alone or in combination of two or more.

  The method for preparing a solution containing a divalent or higher metal ion is not particularly limited, but metal sulfates such as magnesium sulfate, calcium sulfate, zinc sulfate, manganese sulfate, cobalt sulfate, iron sulfate, copper sulfate, and aluminum sulfate; Metal chloride salts such as magnesium chloride, calcium chloride, zinc chloride, manganese chloride, cobalt chloride, iron chloride, copper chloride, aluminum chloride; magnesium carbonate, calcium carbonate, zinc carbonate, manganese carbonate, cobalt carbonate, iron carbonate, copper carbonate Metal carbonates such as aluminum carbonate; metal hydroxides such as magnesium hydroxide, calcium hydroxide, zinc hydroxide, manganese hydroxide, cobalt hydroxide, iron hydroxide, copper hydroxide, aluminum hydroxide, etc. as solvents The method of making it melt | dissolve etc. are mentioned.

  Moreover, you may use the water which originally contains the metal ion more than bivalence as a solution of the metal ion more than bivalence. Such water is not particularly limited, and examples thereof include tap water and well water.

  The amount of divalent or higher valent metal ions contained in the solution is preferably 1 to 50000 mass ppm. If it is 1 mass ppm or more, the unstable monovalent salt remaining in at least the vicinity of the surface layer of the lower cladding pattern 1 can be effectively converted into a stable divalent or higher salt, and 50000 mass ppm (5 Mass%) or less, it can be reduced that excessive divalent or higher metal ions remain in the vicinity of the surface layer. From the above viewpoint, it is more preferably 10 to 10,000 ppm by mass, and further preferably 30 to 5000 ppm by mass.

  There is no particular limitation on the method for exposing the solution containing metal ions having a valence of 2 or more to the exposed surface of the lower clad pattern 1 and the exposed surface of the upper clad pattern 3, but the solution prepared as described above is sprayed. And a method of exposing the exposed surface of the lower cladding pattern 1 and the exposed surface of the upper cladding pattern 3 by a dipping method, a paddle method, a spin method, a brushing method, a scraping method, and the like. Moreover, you may use these methods together as needed.

  The acid of the acidic solution is not particularly limited, inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid; carboxylic acids such as formic acid, acetic acid, malonic acid and succinic acid; lactic acid, salicylic acid, malic acid, tartaric acid and citric acid And the like, and an aqueous solution thereof is preferable. These can be used alone or in combination of two or more. Among these, sulfuric acid or hydrochloric acid is preferable from the viewpoint of high acidity, low volatility, and low oxidizing power.

  The pH of the acidic solution used for washing is preferably more than 0 and 5 or less. If it exceeds 0, the acidity and corrosivity are not too strong, and if it is 5 or less, the excess divalent salt remaining in the lower cladding pattern 1 is effectively used as the original acidic functional group. Can be converted to From the above viewpoint, the pH of the acidic solution is more preferably from 0.1 to 4, and further preferably from 0.3 to 3. The temperature of the acidic solution is adjusted to the pH. Further, an organic solvent, a surfactant, an antifoaming agent, or the like may be mixed in the acidic solution.

Further, the alkaline developer for forming the lower clad pattern 1, the core pattern 2, and the upper clad pattern 3 may be the same solution or different solutions. The acidic solution for washing may be the same solution or a different solution.
Further, the lower clad pattern 1 and the upper clad pattern 3 may be the same solution or different solutions with respect to the solution containing metal ions having a valence of 2 or more.
Hereinafter, each material used in the present embodiment will be described in detail.

[Alkaline developer-soluble resin composition]
The resin composition for forming a core pattern and the resin composition for forming a clad pattern (lower clad pattern 1, upper clad pattern 3) have a phenolic hydroxyl group from the viewpoint of developing a desired pattern using an alkaline developer after exposure. It is preferable that it is a resin composition containing the compound which has a sulfonyl group, a carboxyl group, etc. In particular, a carboxyl group is preferable because strong coordination with a divalent or higher metal ion can be expected.

  Among them, from the viewpoint of transparency, heat resistance, and storage stability, a resin composition for forming an optical waveguide containing (A) a carboxyl group-containing alkali-soluble polymer, (B) a polymerizable compound, and (C) a photopolymerization initiator. Preferably there is.

Hereinafter, the carboxyl group-containing alkali-soluble polymer of component (A) used in the present embodiment will be described.
Although there is no restriction | limiting in particular as a carboxyl group-containing alkali-soluble polymer of (A) component, For example, the polymer represented by following (1)-(6) is mentioned.
(1) A carboxyl group-containing alkali-soluble polymer obtained by copolymerizing a compound having a carboxyl group and an ethylenically unsaturated group in the molecule with another compound having an ethylenically unsaturated group.
(2) Partially introducing an ethylenically unsaturated group into the side chain into a copolymer of a compound having a carboxyl group and an ethylenically unsaturated group in the molecule and another compound having an ethylenically unsaturated group A carboxyl group-containing alkali-soluble polymer obtained in this manner.
(3) A compound having a carboxyl group and an ethylenically unsaturated group in the molecule in a copolymer of a compound having an epoxy group and an ethylenically unsaturated group in the molecule and another compound having an ethylenically unsaturated group And a carboxyl group-containing alkali-soluble polymer obtained by reacting a polybasic acid anhydride with the generated hydroxyl group.
(4) A compound having an hydroxyl group and an ethylenically unsaturated group in the molecule is reacted with a copolymer of an acid anhydride having an ethylenically unsaturated group and another compound having an ethylenically unsaturated group. Obtained carboxyl group-containing alkali-soluble polymer.
(5) A carboxyl group-containing alkali-soluble polymer obtained by reacting a polybasic acid anhydride with a polyaddition product of a bifunctional epoxy resin and a dicarboxylic acid or a bifunctional phenol compound.
(6) A carboxyl group-containing alkali-soluble polymer obtained by reacting a polybasic acid anhydride with a hydroxyl group of a polyaddition product of a bifunctional oxetane compound and a dicarboxylic acid or a bifunctional phenol compound.

Among these, a carboxyl group-containing alkali-soluble polymer represented by the above (1) to (4) is preferable from the viewpoint of transparency and solubility in an alkaline developer. These polymers are (meth) acrylic polymers having a (meth) acryloyl group. Here, the (meth) acryloyl group means an acryloyl group or a methacryloyl group, and the (meth) acrylic polymer uses acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, and derivatives thereof as monomers. , Refers to a polymer obtained by polymerizing this.
The (meth) acrylic polymer may be a homopolymer of the above monomer, or may be a copolymer obtained by polymerizing two or more of these monomers. Furthermore, it is a copolymer containing the above monomer and, if necessary, a monomer other than the above having an ethylenically unsaturated group other than the (meth) acryloyl group as long as the effect of the present embodiment is not impaired. May be. Further, it may be a mixture of a plurality of (meth) acrylic polymers.

The weight average molecular weight of the (A) component carboxyl group-containing alkali-soluble polymer is preferably 1,000 to 3,000,000. If the molecular weight is 1,000 or more, the strength of the cured product is sufficient when the resin composition is used, and if it is 3,000,000 or less, the solubility in a developer composed of an alkaline aqueous solution and (B) polymerization The compatibility with the functional compound is good.
From the above viewpoint, the weight average molecular weight of the component (A) is more preferably 3,000 to 2,000,000, and further preferably 5,000 to 1,000,000.
In addition, the weight average molecular weight in this Embodiment is a value measured by gel permeation chromatography (GPC) and converted into standard polystyrene.

  In the step of forming a pattern by development, the carboxyl group-containing alkali-soluble polymer (A) can have an acid value so that it can be developed with the alkaline developer. For example, when using the said alkaline aqueous solution, it is preferable that an acid value is 20-300 mgKOH / g.

If it is 20 mgKOH / g or more, development is easy, and if it is 300 mgKOH / g or less, the developing solution resistance does not deteriorate. From the above viewpoint, the acid value is more preferably 30 to 250 mgKOH / g, and further preferably 40 to 200 mgKOH / g.
The developer resistance refers to a property that a portion that is not removed by development and becomes a pattern is not affected by the developer.

  Moreover, when using the alkaline quasi-aqueous developing solution which consists of alkaline aqueous solution and 1 or more types of organic solvent, it is preferable that an acid value is 10-260 mgKOH / g. If the acid value is 10 mgKOH / g or more, development is easy, and if it is 260 mgKOH / g or less, the developer resistance is not lowered. From the above viewpoint, the acid value is more preferably 20 to 250 mgKOH / g, and further preferably 30 to 200 mgKOH / g.

  It is preferable that the compounding quantity of (A) component is 10-85 mass% with respect to the total amount of (A) component and (B) component. If it is 10% by mass or more, the strength and flexibility of the cured product of the resin composition for forming an optical waveguide are sufficient, and if it is 85% by mass or less, it is easily entangled by the component (B) during exposure. However, the developer resistance is not insufficient. From the above viewpoint, the blending amount of the component (A) is more preferably 20 to 80% by mass, and further preferably 25 to 75% by mass.

Hereinafter, the polymerizable compound of the component (B) used in the present embodiment will be described.
There is no restriction | limiting in particular as a polymeric compound of (B) component, For example, the compound which has polymeric substituents, such as an ethylenically unsaturated group, the compound which has two or more epoxy groups in a molecule | numerator etc. are mentioned suitably. .

  Specific examples include (meth) acrylates, vinylidene halides, vinyl ethers, vinyl esters, vinyl pyridines, vinyl amides, arylated vinyls, etc. Of these, from the viewpoint of transparency, (meth) acrylates and arylated vinyls. It is preferable that As the (meth) acrylate, any of monofunctional, bifunctional, or trifunctional or higher polyfunctional ones can be used.

There is no restriction | limiting in particular as monofunctional (meth) acrylate, Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, butoxyethyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octyl Heptyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetra Sil (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3- Aliphatic (meth) acrylates such as chloro-2-hydroxypropyl (meth) acrylate and 2-hydroxybutyl (meth) acrylate; cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, di Cyclopentenyl (meth) acrylate, cycloaliphatic (meth) acrylate such as isobornyl (meth) acrylate; phenyl (meth) acrylate, nonylphenyl (meth) acrylate, p-cumylf Nyl (meth) acrylate, o-biphenyl (meth) acrylate, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2 -Hydroxy-3- (o-phenylphenoxy) propyl (meth) acrylate, 2-hydroxy-3- (1-naphthoxy) propyl (meth) acrylate, 2-hydroxy-3- (2-naphthoxy) propyl (meth) acrylate Aromatic (meth) acrylates such as 2-tetrahydrofurfuryl (meth) acrylate, N- (meth) acryloyloxyethylhexahydrophthalimide, 2- (meth) acryloyloxyethyl-N-carbazole and the like (meta ) Acrylate; these These propoxylated compounds; These ethoxylated propoxylated compounds; These caprolactone-modified products, and the like.
Among these, from the viewpoint of transparency and heat resistance, the above alicyclic (meth) acrylates; the above heterocyclic (meth) acrylates; these ethoxylated products; these propoxylated products; these ethoxylated propoxylated products. These caprolactone-modified products are preferable.

There is no restriction | limiting in particular as bifunctional (meth) acrylate, Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethyleneglycol di (Meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1, 3-butanediol di (meth) acrylate, 2-methyl-1,3-propanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, Opentyl glycol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propane Fats such as diol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, glycerin di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate Group (meth) acrylate; cyclohexanedimethanol (meth) acrylate, ethoxylated cyclohexanedimethanol (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, hydrogenated bisphenol A di (meth) acrylate, hydrogenated bisphenol F di ( Meta) Alicyclic (meth) acrylates such as relates; aromatic (meth) acrylates such as bisphenol A di (meth) acrylate, bisphenol F di (meth) acrylate, bisphenol AF di (meth) acrylate, and fluorene di (meth) acrylate A heterocyclic (meth) acrylate such as di (meth) acrylate of isocyanuric acid; an ethoxylated product thereof; a propoxylated product thereof; an ethoxylated propoxylated product thereof; a modified product of caprolactone thereof; a neopentyl glycol type epoxy ( Aliphatic epoxy (meth) acrylates such as meth) acrylate; fats such as cyclohexanedimethanol type epoxy (meth) acrylate, hydrogenated bisphenol A type epoxy (meth) acrylate, and hydrogenated bisphenol F type epoxy (meth) acrylate Cyclic epoxy (meth) acrylate; resorcinol type epoxy (meth) acrylate, bisphenol A type epoxy (meth) acrylate, bisphenol F type epoxy (meth) acrylate, bisphenol AF type epoxy (meth) acrylate, fluorene type epoxy (meth) acrylate And aromatic epoxy (meth) acrylates.
Among these, from the viewpoint of transparency and heat resistance, the above alicyclic (meth) acrylates; the above aromatic (meth) acrylates; the above heterocyclic (meth) acrylates; these ethoxylated products; and these propoxylated products. These ethoxylated propoxy compounds; these caprolactone-modified products; the alicyclic epoxy (meth) acrylates; and the aromatic epoxy (meth) acrylates.

The trifunctional or higher polyfunctional (meth) acrylate is not particularly limited, and is trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth). Aliphatic (meth) acrylates such as acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate; heterocyclic (meth) acrylates such as isocyanuric acid tri (meth) acrylate; ethoxylated products thereof These propoxylated products; these ethoxylated propoxylated products; these caprolactone modified products; phenol novolac-type epoxy (meth) acrylates, cresol novolac-type epoxy (meth) acrylates; And aromatic epoxy (meth) acrylate over bets, and the like.
Among these, from the viewpoint of transparency and heat resistance, the above heterocyclic (meth) acrylates; these ethoxylated products; these propoxylated products; these ethoxylated propoxylated products; these caprolactone modified products; It is preferably a group epoxy (meth) acrylate.

  The above-mentioned monofunctional (meth) acrylate, bifunctional (meth) acrylate, and trifunctional or higher polyfunctional (meth) acrylate can be used alone or in combination of two or more. In addition, (meth) acrylates having different numbers of functional groups can be used in combination. Furthermore, it can also be used in combination with other polymerizable compounds.

  In addition to the (meth) acrylate, a preferable (B) polymerizable compound includes a compound having two or more epoxy groups in the molecule from the viewpoint of compatibility with the (A) carboxyl group-containing alkali-soluble polymer. Also mentioned.

Specifically, hydroquinone type epoxy resin, resorcinol type epoxy resin, catechol type epoxy resin, bisphenol A type epoxy resin, tetrabromobisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, bisphenol AD type epoxy Resin, biphenyl type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, etc. bifunctional phenol glycidyl ether type epoxy resin; hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, hydrogenated 2,2'- Hydrogenated bifunctional phenol glycidyl ether type epoxy resin such as biphenol type epoxy resin, hydrogenated 4,4'-biphenol type epoxy resin; phenol novolac type epoxy resin, cresol novolac Polyfunctional phenol glycidyl ether type epoxy resins such as epoxy resin, dicyclopentadiene-phenol type epoxy resin, dicyclopentadiene-cresol type epoxy resin, tetraphenylolethane type epoxy resin, etc .; polyethylene glycol type epoxy resin , Polypropylene glycol type epoxy resin, neopentyl glycol type epoxy resin, 1,6-hexanediol type epoxy resin, etc. bifunctional aliphatic alcohol glycidyl ether type epoxy resin; cyclohexanediol type epoxy resin, cyclohexanedimethanol type epoxy resin, tri Bifunctional alicyclic alcohol glycidyl ether type epoxy resin such as cyclodecane dimethanol type epoxy resin; Trimethylolpropane type epoxy resin, sorbitol type Trifunctional or higher polyfunctional aliphatic alcohol glycidyl ether type epoxy resin such as poxy resin and glycerin type epoxy resin; Bifunctional aromatic glycidyl ester such as diglycidyl phthalate; Tetrahydrophthalic acid diglycidyl ester, Hexahydrophthalic acid di Bifunctional alicyclic glycidyl esters such as glycidyl ester; bifunctional aromatic glycidyl amines such as N, N-diglycidyl aniline and N, N-diglycidyl trifluoromethylaniline; N, N, N ′, N′-tetra Trifunctional or higher polyfunctional aromatic glycidylamine such as glycidyl-4,4-diaminodiphenylmethane, 1,3-bis (N, N-glycidylaminomethyl) cyclohexane, N, N, o-triglycidyl-p-aminophenol An alicyclic diepoxy acetal, Bifunctional cycloaliphatic epoxy resins such as cyclic diepoxy adipate, alicyclic diepoxy carboxylate, vinylcyclohexene dioxide; 1,2-epoxy-4- of 2,2-bis (hydroxymethyl) -1-butanol Trifunctional or higher polyfunctional alicyclic epoxy resin such as (2-oxiranyl) cyclohexane adduct; Trifunctional or higher functional heterocyclic epoxy resin such as triglycidyl isocyanurate; Silicon-containing organopolysiloxane type epoxy resin A bifunctional or trifunctional or higher polyfunctional epoxy resin is exemplified.
Among these, from the viewpoint of transparency and heat resistance, the above bifunctional phenol glycidyl ether type epoxy resin; the above hydrogenated bifunctional phenol glycidyl ether type epoxy resin; the above trifunctional or more polyfunctional phenol glycidyl ether type epoxy resin; Bifunctional alicyclic alcohol glycidyl ether type epoxy resin; the above bifunctional aromatic glycidyl ester; the above bifunctional alicyclic glycidyl ester; the above bifunctional alicyclic epoxy resin; the above polyfunctional alicyclic epoxy resin; Heterocyclic epoxy resin; the above bifunctional or polyfunctional silicon-containing epoxy resin is preferable.
These compounds can be used alone or in combination of two or more, and can also be used in combination with other polymerizable compounds.

  It is preferable that the compounding quantity of the polymeric compound of (B) component is 15-90 mass% with respect to the total amount of (A) component and (B) component. If it is 15% by mass or more, it can be easily entangled and cured with the carboxyl group-containing alkali-soluble polymer of component (A), and the developer resistance is not insufficient. The film has sufficient film strength and flexibility. From the above viewpoint, the blending amount of the component (B) is more preferably 20 to 80% by mass, and further preferably 25 to 75% by mass.

The component (C) photopolymerization initiator used in the present embodiment will be described below.
(C) There is no restriction | limiting in particular as long as it initiates superposition | polymerization by irradiation of actinic rays, such as an ultraviolet-ray, as a photoinitiator of a component, The compound which has an ethylenically unsaturated group as a polymeric compound of (B) component When used, a photo radical polymerization initiator and the like can be mentioned.

There is no restriction | limiting in particular as radical photopolymerization initiator, benzoin ketals, such as 2, 2- dimethoxy- 1, 2- diphenyl ethane- 1-one; 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1 -Phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4 [4- ( Α-hydroxy ketones such as 2-hydroxy-2-methylpropionyl) benzyl] phenyl} -2-methylpropan-1-one; methyl phenylglyoxylate, ethyl phenylglyoxylate, 2- (2-hydroxyethoxy) oxyphenylacetate Ethyl, 2- (2-oxo-2-phenylacetoxyethoxy) ethyl oxyphenylacetate Of 2-benzyl-2-dimethylamino-1- (4-morpholin-4-ylphenyl) -butan-1-one, 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-ylphenyl) -butan-1-one, 1,2-methyl-1- [4- (methylthio) phenyl]-(4-morpholin) -2-ylpropan-1-one Α-amino ketones such as 1,2-octanedione, 1- [4- (phenylthio), 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl)- 9H-carbazol-3-yl], 1- (O-acetyloxime) and other oxime esters; bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,6-dimethoxy) Benzoyl) -2,4,4-trimethylpentylphosphine oxide, phosphine oxide such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (O-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4, 2,4,5-triarylimidazole dimers such as 5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer; benzophenone, N, N′-tetramethyl -4,4'-diaminobenzophenone, N, N'-tetraethyl-4,4'-diaminobenzophene Non-benzophenone compounds such as 4-methoxy-4'-dimethylaminobenzophenone; 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3 -Quinone compounds such as dimethyl anthraquinone; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin phenyl ether; benzoin compounds such as benzoin, methyl benzoin and ethyl benzoin ; Benzyl compounds such as benzyl dimethyl ketal; 9-phenyl acridine, 1,7-bis (9,9'-acridinyl heptane) or the like of acridine compounds: N- phenylglycine, coumarin and the like.
In the 2,4,5-triarylimidazole dimer, the substituents of the aryl groups at the two triarylimidazole sites may give the same and symmetric compounds, but give differently asymmetric compounds. May be.
The above radical photopolymerization initiators can be used alone or in combination of two or more. Furthermore, it can also be used in combination with an appropriate sensitizer.

  Moreover, when using an epoxy resin as a polymeric compound of (B) component, a photocationic polymerization initiator etc. are mentioned as a photoinitiator of (C) component.

  As a photocationic polymerization initiator, aryl diazonium salts such as p-methoxybenzenediazonium hexafluorophosphate; diaryliodonium salts such as diphenyliodonium hexafluorophosphate and diphenyliodonium hexafluoroantimonate; triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexa Triarylsulfonium salts such as fluoroantimonate, diphenyl-4-thiophenoxyphenylsulfonium hexafluorophosphate, diphenyl-4-thiophenoxyphenylsulfonium hexafluoroantimonate, diphenyl-4-thiophenoxyphenylsulfonium pentafluorohydroxyantimonate; Phenylselenonium hexafluoro Triarylselenonium salts such as sulfate, triphenylselenonium tetrafluoroborate, triphenylselenonium hexafluoroantimonate; dialkylphenacylsulfonium salts such as dimethylphenacylsulfonium hexafluoroantimonate, diethylphenacylsulfonium hexafluoroantimonate Dialkyl-4-hydroxy salts such as 4-hydroxyphenyldimethylsulfonium hexafluoroantimonate and 4-hydroxyphenylbenzylmethylsulfonium hexafluoroantimonate; α-hydroxymethylbenzoin sulfonate, N-hydroxyimide sulfonate, α-sulfo Examples thereof include sulfonic acid esters such as nitroxy ketone and β-sulfonyloxy ketone.

  Among these, the above triarylsulfonium salts are preferable from the viewpoints of curability, transparency, and heat resistance. These thermal and photocationic polymerization initiators can be used alone or in combination of two or more. Furthermore, it can also be used in combination with an appropriate sensitizer.

  (C) It is preferable that the compounding quantity of the polymerization initiator of a component is 0.1-10 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component. If it is 0.1 parts by mass or more, curing is sufficient, and if it is 10 parts by mass or less, sufficient light transmittance is obtained. From the above viewpoint, the blending amount of the component (C) is more preferably 0.3 to 7 parts by mass, and further preferably 0.5 to 5 parts by mass.

  In addition, if necessary, in each pattern forming resin composition used in the present embodiment, an antioxidant, a yellowing inhibitor, an ultraviolet absorber, a visible light absorber, a colorant, a plasticizer You may add what is called additives, such as an agent, a stabilizer, and a filler.

Hereafter, each resin composition for pattern formation used for this Embodiment is demonstrated.
Each pattern forming resin composition used in the present embodiment may be diluted with a suitable organic solvent and used as each pattern forming resin varnish. The organic solvent used here is not particularly limited as long as it can dissolve the resin composition, and is an aromatic hydrocarbon such as toluene, xylene, mesitylene, cumene, p-cymene; tetrahydrofuran, 1,4-dioxane, etc. Cyclic ethers of; alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone; methyl acetate, acetic acid Esters such as ethyl, butyl acetate, methyl lactate, ethyl lactate and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether , Ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol Polyhydric alcohol alkyl ethers such as dimethyl ether and diethylene glycol diethyl ether; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol Polymethyl alcohol alkyl ether acetates such as nomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate; N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc. And amides.
These organic solvents can be used alone or in combination of two or more.
Moreover, it is preferable that the solid content density | concentration in a resin varnish is 20-80 mass% normally.

Hereafter, each resin film for pattern formation used for this Embodiment is demonstrated.
Each pattern forming resin film used in the present embodiment is composed of each of the pattern forming resin compositions, and each pattern forming resin varnish containing the components (A) to (C) is used as a suitable support film. It can be easily manufactured by applying and removing the solvent (solvent). Moreover, you may manufacture by apply | coating each resin composition for pattern formation directly to a support film.

  Although there is no restriction | limiting in particular as a support film, Polyesters, such as a polyethylene terephthalate, a polybutylene terephthalate, a polyethylene naphthalate; Polyolefins, such as polyethylene and a polypropylene; Polycarbonate, polyamide, a polyimide, a polyamideimide, a polyetherimide, a polyether sulfide, polyether Examples include sulfone, polyether ketone, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, and liquid crystal polymer.

  Among these, from the viewpoint of flexibility and toughness, it may be polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, polycarbonate, polyamide, polyimide, polyamideimide, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone. preferable.

Furthermore, it is more preferable to use a highly transparent type support film from the viewpoint of improving the transmittance of exposure actinic rays and reducing the side wall roughness of the core pattern 2. Examples of such highly transparent support films include Cosmo Shine A1517 and Cosmo Shine A4100 (“Cosmo Shine” is a registered trademark) manufactured by Toyobo Co., Ltd.
In addition, from the viewpoint of improving the peelability from the resin layer, a film that has been subjected to a release treatment with a silicone compound, a fluorine-containing compound, or the like may be used as necessary.

  The thickness of the support film may be appropriately changed depending on the intended flexibility, but is preferably 3 to 250 μm. If it is 3 μm or more, the film strength is sufficient, and if it is 250 μm or less, sufficient flexibility is obtained. From the above viewpoint, it is more preferably 5 to 200 μm, and further preferably 7 to 150 μm.

  Among these, it is preferable that the thickness of the support film used for the resin film for core pattern formation is 5-50 micrometers. If it is 5 μm or more, the strength as a support is sufficient, and if it is 50 μm or less, the gap between the photomask and the resin composition layer for forming the core pattern does not increase when the core pattern 2 is formed, and the pattern formability is good. It is. From the above viewpoint, the thickness of the support film used for the core pattern forming resin film is more preferably 10 to 40 μm, and further preferably 15 to 30 μm.

  A photosensitive resin film produced by applying a resin varnish for forming a core pattern or a resin composition for forming a core pattern on a support film is prepared by attaching a protective film on the resin layer as necessary, and a support film, a resin layer, and It is good also as a 3 layer structure which consists of protective films.

  Although there is no restriction | limiting in particular as a protective film, Polyesters, such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyolefin, such as polyethylene and a polypropylene, etc. are mentioned suitably from a softness | flexibility and toughness viewpoint.

  In addition, you may use the film in which the mold release process was given with the silicone type compound, the fluorine-containing compound, etc. from a viewpoint of peelability improvement with a resin layer as needed. The thickness of the protective film may be appropriately changed depending on the intended flexibility, but is preferably 10 to 250 μm. If it is 10 μm or more, the film strength is sufficient, and if it is 250 μm or less, sufficient flexibility is obtained. From the above viewpoint, the thickness is more preferably 15 to 200 μm, and further preferably 20 to 150 μm.

  Although there is no restriction | limiting in particular about the thickness of the resin layer of each pattern formation resin film used for this Embodiment, It is preferable that it is 5-500 micrometers normally by the thickness after drying. If the thickness is 5 μm or more, the thickness is sufficient so that the strength of the resin film or the cured product of the resin film is sufficient, and if it is 500 μm or less, the drying can be performed sufficiently and the amount of residual solvent in the resin film does not increase. When the cured resin film is heated, it does not foam.

  Each pattern-forming resin film thus obtained can be easily stored, for example, by winding it into a roll. Alternatively, a roll-shaped film can be cut into a suitable size and stored in a sheet shape.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
Example 1
<Preparation of resin film A>
[Production of (A) (meth) acrylic polymer (base polymer)]
46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate were weighed in a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 47 parts by mass of methyl methacrylate, 33 parts by mass of butyl acrylate, 16 parts by mass of 2-hydroxyethyl methacrylate, 14 parts by mass of methacrylic acid, 2,2′-azobis (2,4-dimethylvaleronitrile ) A mixture of 3 parts by mass, 46 parts by mass of propylene glycol monomethyl ether acetate and 23 parts by mass of methyl lactate was added dropwise over 3 hours, followed by stirring at 65 ° C. for 3 hours, and further stirring at 95 ° C. for 1 hour. A) A (meth) acrylic polymer solution (solid content: 45% by mass) was obtained.

[Measurement of weight average molecular weight]
(A) The result of measuring the weight average molecular weight (in terms of standard polystyrene) of the (meth) acrylic polymer using GPC (“SD-8022”, “DP-8020”, and “RI-8020” manufactured by Tosoh Corporation), It was 3.9 × 10 ⁴ . As the column, “Gelpack GL-A150-S” and “Gelpack GL-A160-S” manufactured by Hitachi Chemical Co., Ltd. were used.
[Measurement of acid value]
As a result of measuring the acid value of (A) (meth) acrylic polymer, it was 79 mgKOH / g. The acid value was calculated from the amount of 0.1 mol / L potassium hydroxide aqueous solution required to neutralize the (A) (meth) acrylic polymer solution. At this time, the point at which the phenolphthalein added as an indicator changed color from colorless to pink was defined as the neutralization point.

[Preparation of resin varnish A]
(A) As a carboxyl group-containing alkali-soluble polymer, the (A) (meth) acrylic polymer solution (solid content: 45% by mass), 84 parts by mass (solid content: 38 parts by mass), and (B) a polymerizable compound having a polyester skeleton. Urethane (meth) acrylate having 33 parts by mass of “U-200AX” manufactured by Shin-Nakamura Chemical Co., Ltd. and urethane (meth) acrylate having a polypropylene glycol skeleton (“UA-4200” manufactured by Shin-Nakamura Chemical Co., Ltd.) 15 As a mass part, as a thermosetting component, a polyfunctional block isocyanate solution (solid content: 75% by mass) obtained by protecting an isocyanurate type trimer of hexamethylene diisocyanate with methyl ethyl ketone oxime (“Sumijoule BL3175” manufactured by Sumika Bayer Urethane Co., Ltd.) “Sumijour” is a registered trademark.) 20 Parts (solid content 15 parts by mass), (C) 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (BASF) as a photopolymerization initiator "Irgacure 2959" manufactured by Japan Co., Ltd.) 1 part by mass, 1 part by mass of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide ("Irgacure 819" manufactured by BASF Japan Ltd.), and propylene glycol as an organic solvent for dilution 23 parts by mass of monomethyl ether acetate was mixed with stirring. After pressure filtration using a polyflon filter having a pore size of 2 μm (“PF020” manufactured by Toyo Roshi Kaisha, Ltd.), degassing was performed under reduced pressure to obtain resin varnish A.

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

[Measurement of refractive index]
The 50 μm resin film A obtained above with the protective film peeled off was vacuum-pressurized laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) on a silicon substrate (size: length 60 mm, width 20 mm, thickness 0.6 mm). ) And evacuated to 500 Pa or less, and then laminated under conditions of a pressure of 0.4 MPa, a temperature of 50 ° C., and a pressing time of 30 seconds. Subsequently, ultraviolet rays (wavelength 365 nm) were irradiated with 2000 mJ / cm ² with an ultraviolet exposure machine, the support film was peeled off, and further heated at 160 ° C. for 1 hour to prepare a sample for refractive index measurement. The refractive index of the sample at a wavelength of 830 nm was measured using a prism-coupled refractometer (trade name: Model 2020, manufactured by Metricon). The refractive index of the cured resin layer was 1.496.

<Preparation of resin film B>
[Base polymer for forming resin film B; production of (meth) acrylic polymer (P-1)]
In a flask equipped with a stirrer, a cooling pipe, a gas introduction pipe, a dropping funnel, and a thermometer, 42 parts by mass of propylene glycol monomethyl ether acetate and 21 parts by mass of methyl lactate were weighed and stirred while introducing nitrogen gas. . The liquid temperature was raised to 65 ° C., 14.5 parts by mass of N-cyclohexylmaleimide, 20 parts by mass of benzyl acrylate, 39 parts by mass of o-phenylphenol 1.5EO (ethylene oxide) acrylate, 14 parts by mass of 2-hydroxyethyl methacrylate, A mixture of 12.5 parts by weight of methacrylic acid, 4 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), 37 parts by weight of propylene glycol monomethyl ether acetate, and 21 parts by weight of methyl lactate is dropped over 3 hours. Then, it stirred at 65 degreeC for 3 hours, and also continued stirring at 95 degreeC for 1 hour, and the (meth) acrylic polymer (P-1) solution (solid content 45 mass%) was obtained.
As a result of measuring the acid value and the weight average molecular weight of the P-1 solution by the same method as described above, they were 80 mg KOH / g and 32,000, respectively.

[Preparation of resin varnish B]
(A) 60 parts by mass of the P-1 solution (solid content 45% by mass) containing a maleimide skeleton in the main chain as a carboxyl group-containing alkali-soluble polymer, and (B) an ethoxylated bisphenol A diacrylate (Hitachi) as the polymerizable compound Product name: FANCLIL FA-324A ("FANCLIL" is a registered trademark)) 15 parts by mass and ethoxylated bisphenol A diacrylate (manufactured by Hitachi Chemical Co., Ltd., product name: FANCLIL FA-321A, "Fancryl" is a registered trademark.) 15 parts by mass, phenol biphenylene type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name: NC-3000, epoxy equivalent 275 g / eq) 10 parts by mass, (C) as a polymerization initiator , 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-pro 1-part of N-1-one (BASF Japan KK, trade name: Irgacure 2959), bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (BASF Japan KK, trade name: Irgacure 819) 1 Mass parts were weighed into a wide-mouthed plastic bottle, and stirred for 6 hours using a stirrer under conditions of a temperature of 25 ° C. and a rotational speed of 400 min ⁻¹ to prepare resin varnish B. Thereafter, using a polyflon filter having a pore diameter of 2 μm (trade name: PF020, manufactured by Toyo Roshi Kaisha, Ltd.) and a membrane filter having a pore diameter of 0.5 μm (trade name: J050A, manufactured by Toyo Roshi Kaisha, Ltd.), temperature 25 ° C., pressure 0 Pressure filtration was performed under the condition of 4 MPa. Subsequently, defoaming was performed under reduced pressure for 15 minutes using a vacuum pump and a bell jar under conditions of a reduced pressure of 50 mmHg to obtain a resin varnish B.

[Preparation of Resin Film B]
The resin varnish B is applied to a non-treated surface of a PET film (manufactured by Toyobo Co., Ltd., trade name: A1517, thickness 16 μm) using a coating machine (Hirano Techseed Co., Ltd., multi-coater, trade name: TM-MC). Then, it was dried at 100 ° C. for 20 minutes, and then a release PET film (manufactured by Teijin DuPont Films, trade name: Purex A31, thickness 25 μm) was attached as a protective film to obtain a resin film B. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine, and the thickness after drying will be described later.

[Measurement of refractive index]
When the refractive index of the cured resin layer was measured by the same method as described above, the refractive index was 1.555.
(Production of optical waveguide)
Thickness as a substrate: Resin film A (for forming a lower clad pattern) having a protective film peeled over the entire surface of a polyimide substrate (trade name: Kapton EN, manufactured by Toray DuPont Co., Ltd.) having a size of 25 μm, length 100 mm, width 100 mm After using the vacuum pressurization type laminator (trade name: MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) to evacuate to 500 Pa or less, pressure 0.7 MPa, temperature 70 ° C., pressurization time 30 Thermocompression bonding was performed under the conditions of seconds. Thereafter, ultraviolet rays (wavelength 365 nm) are passed through a PET film using a UV exposure machine (trade name: EV-800, manufactured by Hitachi Via Mechanics Co., Ltd.) through a negative photomask having an opening having a width of 4 mm and a length of 50 mm. ) Was irradiated at 0.4 J / cm ² .
Thereafter, the PET film was peeled off, developed using a 1% by mass aqueous potassium carbonate solution, which is an alkaline developer, using a spray method, and then washed with pure water to form a lower clad pattern (step A).
Next, a 1 mass% calcium chloride aqueous solution as divalent or higher metal ions was exposed using a spray method to impregnate the lower clad pattern with calcium ions, and then washed with pure water (step A1).
Next, it was washed with a 1% by mass sulfuric acid aqueous solution using a spray method, and then washed with pure water and dried (step A2).
Then, after further photocuring was performed by irradiating 4 J / cm ² (wavelength 365 nm) using the above exposure machine, the lower clad pattern was thermally cured by heating at 170 ° C. for 1 hour.

Next, the resin film B from which the protective film was peeled (used as a resin layer for core pattern formation) was thermocompression bonded onto the lower clad pattern under the same conditions as described above using the vacuum pressurizing laminator. Then, through a negative photomask having an opening (12 pieces) having a width of 50 μm and a length of 50 mm, the above exposure machine was used to irradiate 3 J / cm ² (wavelength 365 nm), and then the PET film was peeled off. It developed using 1 mass% potassium carbonate aqueous solution, and washed with pure water (process B). Subsequently, it was washed with a 1% by mass sulfuric acid aqueous solution (step B1), then washed with pure water and dried. Then, after further photocuring was performed by irradiating 4 J / cm ² (wavelength 365 nm) using the above exposure machine, the film was heat-cured at 170 ° C. for 1 hour to form a width of 50 μm on the lower cladding pattern. Twelve core patterns having a thickness of 50 μm were formed. There was no peeling of the core pattern due to development.

The obtained core pattern was cut using a dicing saw (DAC552, manufactured by DISCO Corporation) equipped with a dicing blade having an inclined surface of 45 ° to form an optical path conversion mirror having an inclined surface of 45 ° (FIG. 1) The right core pattern in 1 is used for optical signal transmission) (Step C).
The inclined surface of the obtained optical path conversion mirror was 45 ° with respect to the surface of the lower cladding pattern. There was no peeling of the core pattern due to dicing.

Next, the resin film A from which the protective film is peeled (used as an upper clad pattern forming resin) is vacuumed to 500 Pa or less using a vacuum pressure laminator (trade name: MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.). After drawing, the film was thermocompression bonded onto the core pattern under the conditions of a pressure of 0.7 MPa, a temperature of 70 ° C., and a pressing time of 30 seconds. After that, through a negative photomask having a 150 μm square light-shielding part, the optical path conversion mirror is positioned so as to be located in the light-shielding part, and the above-mentioned ultraviolet exposure machine (trade name: EV-800, manufactured by Hitachi Via Mechanics Co., Ltd.) Using UV, ultraviolet light (wavelength 365 nm) was irradiated through a PET film at 0.5 J / cm ² , and then the PET film was peeled off and developed using a 1% by mass potassium carbonate aqueous solution using a spray method. Washing with water was performed to form an opening exposing the inclined surface (see FIG. 1, the substrate is not shown) (step D). No peeling between the upper clad pattern, the core pattern and the lower clad pattern was observed.
Subsequently, it was washed with a 1% by mass sulfuric acid aqueous solution using a spray method, then washed with pure water and dried.
Next, a 1% by mass calcium chloride aqueous solution was exposed using a spray method to impregnate calcium ions with each surface constituting the upper clad pattern and the opening, and then washed with pure water (step D1).
Next, it was washed with a 1% by mass sulfuric acid aqueous solution and then washed with pure water and dried.
Then, after further photocuring was performed by irradiating 4 J / cm ² (wavelength 365 nm) using the above exposure machine, the upper clad pattern was thermally cured by heating at 170 ° C. for 1 hour.

  The upper clad pattern had a thickness having a surface 15 μm above the upper surface of the core pattern. The optical path conversion mirror was included in the opening.

  Next, the distance from the optical path conversion mirror to the end face of the core pattern provided on the outer shape line was 10 mm, which was subjected to outer shape processing using a dicing saw (DAC552, manufactured by DISCO Corporation) equipped with a rectangular dicing blade.

  850 nm light was incident from the end face of the obtained optical waveguide using a GI50 optical fiber, and a light receiving optical fiber of GI50 was placed on the substrate side where the optical path was changed from the optical path conversion mirror, and the optical loss was measured. However, it was 0.6 dB.

  Next, the obtained optical waveguide was allowed to stand for 2000 hours in a temperature 85 ° C. and humidity 85% RH (relative humidity) environment, and then the optical loss was measured again. As a result, the optical loss did not change to 0.6 dB. . When the appearance of the inclined surface was confirmed, there were no defects (bleed out, etc.). When the appearance of the end face was confirmed, there were no defects (bleed out, etc.).

  Next, another optical waveguide with a mirror (initial value 0.5 dB) manufactured by the same method as described above was left to stand for 2000 hours in an environment of temperature 65 ° C. and humidity 95% RH, and then the optical loss was measured again. The optical loss was almost unchanged at 0.6 dB. When the appearance of the inclined surface was confirmed, there were no defects (bleed out, etc.). When the appearance of the end face was confirmed, there were no defects (bleed out, etc.).

Example 2
In Example 1, an optical waveguide was produced in the same manner as in Example 1 except that the optical path conversion mirror was further cut off using the dicing saw to obtain an optical waveguide without an optical path conversion mirror.
When 850 nm light was incident from one end face using a GI50 optical fiber and a GI50 light receiving optical fiber was placed on the other end face, the optical loss was measured and found to be 0.2 to 0.3 dB. It was.
Similar to Example 1, the light loss fluctuation after leaving for 2000 hours in the environment of temperature 85 ° C., humidity 85% RH, 65 ° C., humidity 95% RH was almost unchanged at 0.0 to 0.1 dB. . When the appearance of the end face was confirmed, there were no defects (bleed out, etc.).

Example 3
An optical waveguide with a mirror was produced in the same manner as in Example 1 except that the calcium chloride used for the lower clad pattern and the upper clad pattern was changed to magnesium chloride.
The initial optical characteristics of the obtained optical waveguide with a mirror are 0.5 to 0.7 dB, after being left for 2000 hours in a temperature 85 ° C., humidity 85% RH environment, 65 ° C., humidity 95% RH environment, respectively. The optical loss variation was 0.0 to 0.1 dB, almost unchanged. When the appearance of the inclined surface was confirmed, there were no defects (bleed out, etc.). When the appearance of the end face was confirmed, there were no defects (bleed out, etc.).

Example 4
In Example 3, an optical waveguide was manufactured in the same manner except that the optical path conversion mirror was further cut off using the dicing saw to obtain an optical waveguide without an optical path conversion mirror.
When 850 nm light was incident from one end face using a GI50 optical fiber and a GI50 light receiving optical fiber was placed on the other end face, the optical loss was measured and found to be 0.2 to 0.3 dB. It was.
Similar to Example 1, the light loss fluctuation after leaving for 2000 hours in the environment of temperature 85 ° C., humidity 85% RH, 65 ° C., humidity 95% RH was almost unchanged at 0.0 to 0.1 dB. . When the appearance of the end face was confirmed, there were no defects (bleed out, etc.).

Example 5
An optical waveguide with a mirror was produced in the same manner as in Example 1 except that hydrochloric acid was used as the sulfuric acid used for the lower clad pattern and the upper clad pattern.
The initial optical characteristics of the obtained optical waveguide with a mirror are 0.5 to 0.6 dB, and after standing for 2000 hours in a temperature 85 ° C., humidity 85% RH environment, 65 ° C., humidity 95% RH environment, respectively. The optical loss variation was 0.0 to 0.1 dB, almost unchanged. When the appearance of the inclined surface was confirmed, there were no defects (bleed out, etc.). When the appearance of the end face was confirmed, there were no defects (bleed out, etc.).

Comparative Example 1
In Example 1, an optical waveguide was produced in the same manner except that the lower clad pattern was not impregnated with divalent metal ions with calcium chloride.
The initial optical characteristics of the obtained optical waveguide with a mirror were 0.5 to 0.7 dB.
When an optical waveguide with a mirror having an initial characteristic of 0.5 dB was left for 2000 hours in an environment of a temperature of 85 ° C. and a humidity of 85% RH, the optical characteristic deteriorated to 1.0 dB. When the appearance of the inclined surface was confirmed, bleed out occurred. When the appearance of the end face was confirmed, a bleed out occurred from the lower clad pattern, and was applied to the end face of the core pattern.
When another mirrored optical waveguide having an initial characteristic of 0.7 dB was left for 2000 hours in an environment of 65 ° C. and a humidity of 95% RH, the optical characteristic deteriorated to 1.1 dB. When the appearance of the inclined surface was confirmed, bleed out occurred. When the appearance of the end face was confirmed, a bleed out occurred from the lower clad pattern, and was applied to the end face of the core pattern.

Reference example 1
In Example 1, an optical waveguide was manufactured by the same method except that the lower clad pattern was not washed with sulfuric acid. When the core pattern was developed, one of the 12 core patterns was peeled off. It was. When the optical path conversion mirror was provided in the same manner as in Example 1, one core pattern was peeled off.
Similar to Example 1, the light loss fluctuation after leaving for 2000 hours in the environment of temperature 85 ° C., humidity 85% RH, 65 ° C., humidity 95% RH was almost unchanged at 0.0 to 0.1 dB. . When the appearance of the inclined surface was confirmed, there were no defects (bleed out, etc.). When the appearance of the end face was confirmed, there were no defects (bleed out, etc.).
The measurement results of Examples 1 to 5, Comparative Example 1 and Reference Example 1 are shown together in Table 1.

  In Comparative Example 1 that does not depend on the optical waveguide manufacturing method of the present invention, the optical loss due to the environmental reliability test is deteriorated and bleed out occurs. On the other hand, in the method for manufacturing an optical waveguide according to the present invention, bleed-out does not occur, and optical loss due to an environmental reliability test does not deteriorate.

  The optical waveguide with a mirror obtained by the optical waveguide with a mirror of the present invention has reduced optical loss deterioration by various environmental reliability tests, and the optical module, optical interconnection, optical member, and optical waveguide in a part of the optical path It is applicable to a wide range of fields such as optical transmission cables using

1. 1. Lower clad pattern 2. Core pattern 3. Upper clad pattern Inclined surface (optical path conversion mirror)
5. Aperture

Claims (10)

Step A, exposing the lower clad pattern forming resin layer to pattern exposure and developing with an alkaline developer to form a lower clad pattern
A method of manufacturing an optical waveguide comprising at least a step B of laminating a core pattern forming resin layer on the lower clad pattern, pattern exposure of the core pattern forming resin layer, and development with an alkaline developer to form a core pattern Because
A method for manufacturing an optical waveguide, comprising the step A1 of impregnating the lower cladding pattern with a metal ion having a valence of 2 or more in the step A.   2. The method for manufacturing an optical waveguide according to claim 1, wherein the step A includes a step A <b> 2 of cleaning the lower clad pattern with an acidic solution after the step A <b> 1.   3. The method for manufacturing an optical waveguide according to claim 1, further comprising a step B <b> 1 of washing the core pattern with an acidic solution in the step B. 4.   The manufacturing method of the optical waveguide as described in any one of Claims 1-3 which has the process C which forms an optical path conversion mirror in the said core pattern after the said process B.   After the step C, an upper clad pattern-forming resin layer is laminated so as to cover the upper surface and side surfaces of the core pattern, the upper clad pattern-forming resin layer is subjected to pattern exposure, and developed with an alkaline developer to form an upper clad. The method for manufacturing an optical waveguide according to claim 4, further comprising a step D in which the optical path conversion mirror is included in the opening portion that has been removed by development as a pattern.   6. The method of manufacturing an optical waveguide according to claim 5, further comprising a step D1 of impregnating the upper cladding pattern with a metal ion having a valence of 2 or more in the step D.   The method for producing an optical waveguide according to claim 1, wherein the divalent or higher-valent metal ion is at least one of calcium ion and magnesium ion.   The method for manufacturing an optical waveguide according to claim 2, wherein the acidic solution is at least one of sulfuric acid and hydrochloric acid.   The resin composition containing at least one of the resin layer for lower clad pattern formation, the resin layer for core pattern formation, and the resin layer for upper clad pattern formation is a resin composition containing a compound having a carboxyl group. The manufacturing method of the optical waveguide as described in any one of Claims.   At least one of the lower clad pattern-forming resin layer, the core pattern-forming resin layer, and the upper clad pattern-forming resin layer comprises (A) a carboxyl group-containing alkali-soluble polymer, (B) a polymerizable compound, and C) The method for producing an optical waveguide according to claim 1, which is a resin composition containing a photopolymerization initiator.

Images