JP2003114351A - Optical fiber array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber array which can accurately transmit a light signal so that when the optical fiber array is manufactured, its flank is not ground largely or some of end surfaces of the optical fibers is not ground obliquely. SOLUTION: The optical fiber array which has a plurality of grooves formed in a part of the top surface of a substrate and also has the optical fibers housed in the grooves via adhesives and on which a lid part partially housing the optical fibers is fitted to the substrate is characterized in that a recessed part for partially housing the optical fibers together is formed on the surface of the lid part which faces the substrate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical fiber array.

[0002]

2. Description of the Related Art In recent years, attention has been focused on optical fibers mainly in the communication field. Particularly in the IT (information technology) field, communication technology using optical fibers is required to maintain a high-speed Internet network. Optical fiber has the features of low loss, high bandwidth, small diameter / light weight, no induction, resource saving, etc. In the communication system using the optical fiber having this feature, the communication using the conventional metallic cable is used. Compared with the system, the number of repeaters can be greatly reduced, construction and maintenance are facilitated, and the communication system can be made economical and highly reliable.

Further, in the optical fiber, not only the light of one wavelength but also the light of many different wavelengths can be simultaneously multiplexed and transmitted by one optical fiber, so that it has a large capacity for various purposes. This has a great advantage that a transmission line can be realized and a video service can be supported.

Further, in optical fiber communication, in order to connect the optical fiber to a light receiving element, a terminal device (personal computer, mobile, game, etc.) directly or through an optical waveguide or the like, a plurality of optical fibers are arranged at predetermined intervals. In order to achieve this, an optical fiber array is used.

Conventionally, as an optical fiber array, for example, an optical fiber array in which optical fibers are housed in alignment with each of a plurality of V-grooves and the optical fibers are fixed via an adhesive is disclosed. ing. In such an optical fiber array, in order to protect the optical fiber housed in the V-groove of the substrate, a plate-like lid is usually adhered onto the substrate via an adhesive.

[0006]

In such a conventional optical fiber array, the optical fiber is misaligned, the surface of the optical fiber is scratched, or an optical signal is desired through the optical fiber. Sometimes it was not emitted in the direction. Then, the inventors of the present invention diligently studied the cause of such an inconvenience, and it became clear that the cause was the polishing treatment step at the time of manufacturing. This will be described below with reference to the drawings.

FIG. 9A is a perspective view schematically showing an embodiment of a conventional optical fiber array, and FIG. 9B is a perspective view thereof.
It is a partial top view of (a), (c) is AA of (a).
It is a line sectional view, and (d) is a BB line partial sectional view of (a). As shown in FIG. 9A, in the conventional optical fiber array 400, a plurality of V grooves 457 are formed on the substrate 451.
Are formed in parallel, and an optical fiber 415 is housed in each of the V grooves 457 via an adhesive 459.
Further, a substantially plate-shaped lid portion 460 is placed and fixed on the upper surface of the substrate 451 via an adhesive 469.

When manufacturing such a conventional optical fiber array, first, a plurality of Vs for accommodating optical fibers are stored.
A substrate having a groove is created, and then an optical fiber is placed and housed in the groove of the substrate via an adhesive, and further, a substantially plate-shaped lid is mounted on the substrate in which the optical fiber is housed via the adhesive. The optical fiber array was manufactured by attaching the parts. Further, in the optical fiber array manufactured in this manner, if the end face of the optical fiber is perpendicular to the bottom surface of the substrate, light is generated even when an optical signal is transmitted, which causes an error in the optical signal. Since it may hinder transmission, usually, by polishing the end face of the optical fiber,
As shown in (d), the end face is inclined, and for example, the angle θ formed by this end face and the vertical direction is about 8 °.

As described above, when the end face of the optical fiber array is tilted, the problem that the returning light is generated during the transmission of the optical signal is solved, but when the end face is subjected to the polishing treatment so as to be tilted. The following problems may occur. That is, as shown in (c), when the shape of the lid is a plate-shaped body, the amount of resin (adhesive) is large in the vicinity of the side surface of the optical fiber array. Tend to be easily polished,
As shown in (b), the vicinity of the side surface of the optical fiber array was largely scraped off, and the shape of the vicinity of the side surface of the optical fiber in a plan view sometimes became a curved shape (see a portion C in the figure). ).

As described above, when the vicinity of the side surface of the optical fiber array is largely shaved off, the end surface of the optical fiber housed in the groove near the side surface of the substrate is excessively polished, or a part of the end surface of the optical fiber is obliquely polished. As a result, misalignment of the optical fiber occurs, peeling occurs between the optical fiber and the adhesive, cracks occur in the adhesive, and the surface of the optical fiber is damaged. There was something that happened. Further, when a part of the end surface of the optical fiber is polished obliquely, an optical signal may be obliquely emitted from the end surface of the optical fiber, and the optical signal may not be accurately transmitted. FIG. 9 is a schematic diagram for explaining a conventional optical fiber array, and in the perspective view shown in FIG. 9A, the inclination of the end face of the optical fiber array and the polishing state near the side face are difficult to understand. However, in reality, it has an inclined and polished state as shown in the partial sectional view of (d) and the partial plan view of (b).

[0011]

Therefore, the present inventors have
As a result of diligent study, as a lid, on the surface facing the substrate,
By using the one in which the concave portion for accommodating a part of the optical fiber is formed, even if the polishing treatment is performed to make the end faces of the substrate, the optical fiber and the lid part inclined at the time of manufacture, It has been found that the side surface of the fiber array is not largely scraped off as compared with the vicinity of the center of the substrate, and the optical fiber array of the present invention has been completed.

That is, the optical fiber array of the present invention is
A plurality of grooves are formed in a part of the upper surface of the substrate, an optical fiber is accommodated in the groove through an adhesive, and a lid part for accommodating a part of the optical fiber is attached on the substrate. The fiber array is characterized in that a recess for accommodating a part of the optical fibers is formed on a surface of the lid portion facing the substrate.

Further, in the optical fiber array of the present invention, the lid is preferably made of an inorganic material or a metal material, and the inorganic material is preferably ceramic or silicon.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The optical fiber array of the present invention is the optical fiber array of the present invention, wherein a plurality of grooves are formed in a part of the upper surface of the substrate, and the optical fibers are accommodated in the grooves via an adhesive. In the optical fiber array in which a lid portion for accommodating a part of the optical fiber is attached on the substrate, a part of the optical fiber is collectively attached to a surface of the lid portion facing the substrate. It is characterized in that a concave portion for accommodating is stored.

In the optical fiber array of the present invention, the optical fiber array is provided with the lid portion on the surface facing the substrate, in which the concave portion for accommodating a part of the optical fiber is formed. The amount of resin near the side surface of the fiber array is not greater than that near the center of the optical fiber array, and the end surfaces of the substrate, optical fiber, and lid are polished to make the end surface of the optical fiber array inclined. Even if the above process is performed, the vicinity of the side surface of the optical fiber array is not largely scraped off, and a part of the end face of the optical fiber is not obliquely polished. Therefore, the above-described inconvenience does not occur, and the optical fiber array of the present invention can accurately transmit an optical signal.

The optical fiber array of the present invention will be described with reference to the drawings. FIG. 1A is a partial perspective view schematically showing an example of the optical fiber array of the present invention,
(B) is a perspective view showing only the lid part attached to the optical fiber array, and (c) is a sectional view taken along the line AA of (a).

As shown in FIG. 1, the optical fiber array 10
0, a plurality of V grooves 157 are formed in parallel on the substrate 151, and the optical fiber 11 is provided in each of the V grooves 157.
5 is stored via an adhesive 159. In addition to the groove 157, a coating resin layer holding portion 158 for collectively holding the optical fiber together with the coating resin layers 113 and 114 around the groove is formed on the upper surface of the substrate 151.
The upper surface of the coating resin layer holding portion 158 has a groove 157.
It is lower than the groove forming surface on which is formed. The coating resin layer 114 is fixed to the coating resin layer holding portion 158 by an adhesive layer (not shown) formed around the coating resin layer 114.
The covering resin layer holding portion 158 may be formed as necessary, and only the V groove may be formed on the substrate. In the figure, 111 is a core and 112 is a clad. Further, instead of the coating resin layer holding portion, a recess may be formed on the substrate, which can accommodate the optical fiber together with the surrounding coating resin layer. It should be noted that the shape of the concave portion here is, for example, a shape in which the side outer edge portion of the coating resin layer holding portion shown in FIG. 1 has the same height as the upper surface of the substrate or a wall surface lower than this is provided. Can be mentioned.

The optical fiber array 100 shown in FIG.
In the above, four optical fibers are stored, but the number of optical fibers stored in the groove of the optical fiber array of the present invention is not limited to four and may be three or less. However, it may be five or more.

In the optical fiber array 100,
A lid 160 is attached on the region where the groove 157 for accommodating the optical fiber 115 is formed.
A recessed portion 161 is formed in 60 for accommodating a part of the optical fiber 115 (a portion of the optical fiber which is not accommodated in the groove 157) in a lump. An adhesive 169 is also filled in the gap between the recess 161 and the optical fiber. The outer edge of the substrate 151 and the outer edge of the lid 160 are in close contact with each other with an adhesive layer 179.

In the optical fiber array having such a lid, not only the adhesive but also a part of the lid (the wall surface of the recess formed in the lid) is provided in the gap between the substrate and the lid near the side surface. Therefore, even when the polishing process is performed to give the end face of the optical fiber array an inclination, the vicinity of the side face of the optical fiber array is not largely scraped off,
Therefore, a part of the end face of the optical fiber is not polished obliquely. Therefore, in the optical fiber array of the present invention,
It is possible to accurately transmit an optical signal without causing a positional deviation of the optical fiber or obliquely emitting light from the optical fiber.

Further, the concave portion formed in the lid portion and having a shape for accommodating a part of the optical fibers collectively is easier to form than the concave portion having a shape for accommodating the individual optical fibers separately, Further, since there is a gap between the optical fibers housed in the recesses, relative positional deviation of the optical fibers is unlikely to occur, and furthermore, an adhesive or the like is easily filled in the gap.

Further, the recess 161 formed in the lid 160 shown in FIG. 1 is formed such that the wall surface thereof is substantially perpendicular to the upper surface of the substrate 151, and its cross section is formed by combining only planes. is there. The shape of the recess is not limited to the shape described above, and the wall surface may have a shape having an inclined surface, a shape having a curved surface, a shape combining a flat surface and a curved surface, or the like. . Further, in the optical fiber array 100 shown in FIG. 1, the lid 60 having a shape that covers only the grooved region of the substrate is attached, but in the optical fiber array of the present invention, the shape of the lid is the same as that of the substrate. It may be a shape that covers the entire surface (a shape that integrally covers the grooved region and the covering resin layer holding portion (see FIG. 8B)). In addition, a lid having a shape that covers only the grooved region of the substrate and a lid that has a shape that covers only the coating resin layer holding portion may be separately attached.

Further, the depth of the concave portion for accommodating the optical fibers formed in the lid portion at one time is preferably 95% or less of the diameter of the optical fibers. The depth of the recess is
If the diameter of the optical fiber exceeds 95%, the optical fiber may occupy a small portion in the recess depending on the depth of the groove formed on the upper surface of the substrate, and the optical fiber may be displaced in the vertical direction. The depth of the recess is preferably the same as the height of the portion of the optical fiber accommodated in the recess.

Examples of the material of the lid include inorganic materials such as silicon, silicon carbide, alumina, aluminum nitride, mullite, ceramics, gallium arsenide, zirconia, quartz and glass; metallic materials such as copper, iron and nickel; Examples thereof include thermosetting resins, thermoplastic resins, photosensitive resins, organic materials such as composites thereof, and those obtained by impregnating these organic materials with a reinforcing material such as glass fiber. Among these, inorganic materials or metallic materials are desirable. This is because it is less deformed by heat and humidity and has excellent mechanical strength.

Particularly, glass or quartz is preferable. When using a lid made of glass or quartz,
An ultraviolet curable adhesive can be used as an adhesive to be filled between the substrate and the optical fiber. This is because the lid made of these materials transmits ultraviolet rays. When a lid made of a material that does not transmit light such as ultraviolet rays is used, a thermosetting adhesive is used as the adhesive filled between the lid and the substrate.

The optical fiber array 100 shown in FIG.
In the substrate 151, a plurality of V grooves 157 are formed.
The optical fiber ribbon 110 in which the optical fiber is exposed by removing the coating resin layer at one end is housed in. The optical fiber ribbon is not particularly limited, and a conventionally known one can be used. For example, a primary coating resin layer is formed around an optical fiber 115 composed of a core 111 and a clad 112 as shown in FIG. It is possible to use the optical fiber ribbon 110 in which the optical fibers 115 coated with the primary coating resin layer are collectively arranged with the secondary coating resin layer while the optical fibers 115 are arranged in parallel.

Optical fiber 1 constituting an optical fiber ribbon
As 15, there are, for example, a silica-based optical fiber whose main component is silica glass (SiO ₂ ), a multi-component optical fiber whose main component is soda lime, glass, borosilicate glass, and a plastic such as silicone resin or acrylic resin. Examples include plastic optical fibers containing as a main component. Of these, quartz optical fiber is desirable.

The primary coating resin layer 113 plays a role as a protective layer for preventing the optical fiber from being damaged. The material is not particularly limited,
For example, a thermosetting resin such as an epoxy resin, a silicone resin, a urethane resin, a phenol resin, a polyimide resin, a polyolefin resin, or a fluororesin, or methacrylic acid or acrylic acid is used, and the thermosetting group of the thermosetting resin described above is used. Examples thereof include (meth) acrylated photosensitive resins. The number of the primary coating resin layers is not limited to one and may be two or more.

The secondary coating resin layer 114 plays a role of protecting the optical fibers formed around the primary coating resin layer and maintaining the shape of the optical fiber ribbon in which the optical fibers are arranged in parallel. There is. The material is not particularly limited, and examples thereof include the same thermosetting resin and photosensitive resin as the material of the primary coating resin layer. The number of the secondary coating resin layers is not limited to one, and
It may be more than one layer.

In the optical fiber array 100,
It is desirable that the coating resin layer is removed and a roughened surface (not shown) is formed on the surface of the optical fiber housed in the V groove 157. The roughened surface has an average roughness Ra of 1
It is desirable that the thickness is ˜100 nm. The average roughness Ra is
If it is less than 1 nm, the adhesiveness between the optical fiber and the adhesive is hardly improved, while if the average roughness Ra exceeds 100 nm, the unevenness of the surface of the optical fiber becomes large, so that the cross-sectional shape of the roughened surface is circular. The optical fiber may be out of shape, and the optical fiber is likely to be displaced, which may adversely affect optical signal transmission. The more desirable average roughness Ra of the roughened surface is 1
It is 0 to 50 nm.

The method for forming the roughened surface is not particularly limited, but it is desirable to use a roughening solution containing fluoride. This is because a roughened surface having an average roughness Ra within the above range can be formed in a short time.

As the roughening liquid containing the above-mentioned fluoride, for example, HF aqueous solution, HF-NH ₄ F mixed liquid, NaF aqueous solution, BaF ₂ aqueous solution, KF aqueous solution, CaF ₂ aqueous solution, X
Examples include eF ₂ aqueous solution. Among these, HF
A solution containing is desirable. This is because a roughened surface having a desired average roughness Ra can be formed in a short time without adversely affecting the optical fiber (deformation of the optical fiber, etc.). It is suitable for forming a roughened surface on the surface of an optical fiber.

Further, in the optical fiber array 100, the optical fiber ribbon from which the coating resin layer at one end is removed is housed in the substrate, but the optical fiber housed in the groove of the substrate is a plurality of single fibers. It may be a core optical fiber or a laminated optical fiber ribbon in which a plurality of optical fiber ribbons are stacked. When a laminated optical fiber ribbon is used, a plurality of optical fibers can be arranged in high density in parallel in the groove of the substrate.

FIG. 2 (a) is a partial perspective view schematically showing an example of an optical fiber array of the present invention using a laminated optical fiber ribbon, and FIG. 2 (b) shows only a lid part attached to the optical fiber array. FIG. 4C is a perspective view showing the above, and FIG. 7C is a sectional view taken along line AA of FIG. As shown in FIG. 2, in the optical fiber array 200, the exposed optical fibers 235 and 245 at one end of the laminated optical fiber ribbon 210 are housed in the V groove 257 on the upper surface of the substrate 251 via the adhesive 259. Further, on the upper surface of the substrate 251, apart from the V groove 257,
A coating resin layer holding portion 258 for holding the laminated optical fiber ribbon 210 together with the coating resin layer is formed. In addition, the upper surface of the coating resin layer holding portion 258 has the groove 2
It is lower than the groove forming surface on which 57 is formed. Also,
This coating resin layer is fixed to the coating resin layer holding portion 258 by an adhesive layer (not shown) formed around it. Further, also in such an optical fiber array using the laminated optical fiber ribbon, as described above, the laminated optical fiber ribbon is housed together with the coating resin layer in place of the coating resin layer holding portion on the substrate. A recess that can be formed may be formed.

Also in the optical fiber array 200, the substrate 251 in which the laminated optical fiber ribbon 210 is housed
A lid 260 is formed on the top of the lid 260.
A recessed portion 261 is formed in which a part of the optical fibers 235 and 245 (a part of the optical fiber that is not housed in the groove 257) is housed together. The adhesive 269 is also filled in the gap between the recess 261 and the optical fiber. Further, the outer edge portion of the substrate 251 and the outer edge portion of the lid portion 260 are in close contact with each other via the adhesive layer 279.

In the laminated optical fiber ribbon 210, two optical fiber ribbons 230 and 240 each having an exposed optical fiber at one end are stacked, and the exposed optical fiber 245 of the lower optical fiber ribbon 240 and the upper optical fiber ribbon 245 of the upper optical fiber ribbon 240 are stacked. The exposed optical fibers 235 of the optical fiber ribbon 230 are alternately arranged.

In the laminated optical fiber ribbon 210,
The exposed optical fibers 235, 245 are arranged so that the exposed optical fibers 235, 245 are arranged at the same height.
Each is bent in part. In the laminated optical fiber ribbon 210, the upper optical fiber ribbon 2
Although the exposed optical fibers 235 of 30 and the exposed optical fibers 245 of the lower optical fiber ribbon 240 are partly bent, both optical fibers can be arranged at the same height. If so, only the exposed optical fiber of the upper optical fiber ribbon may be bent, or only the exposed optical fiber of the lower optical fiber ribbon may be bent.

In the laminated optical fiber ribbon 210, it is desirable that the upper optical fiber ribbon 230 and the lower optical fiber ribbon 240 are fixed to each other with an adhesive or the like. This is because the positional deviation of the optical fibers arranged in parallel at high density is less likely to occur.

Further, as described above, in the optical fiber array of the present invention, the optical fibers are housed in the groove via the adhesive. Further, it is desirable that the gap between the optical fiber and the recess formed in the lid is filled with an adhesive.

Examples of the adhesive include those containing at least one of a thermoplastic resin, a thermosetting resin, and a photosensitive resin such as an ultraviolet curable resin.
Among these, a thermosetting resin and a photosensitive resin such as an ultraviolet curable resin are preferable. Examples of the thermosetting resin include epoxy resin, phenol resin, silicone resin, polyimide resin, and fluororesin.

Examples of the epoxy resin include bisphenol type epoxy resin and novolac type epoxy resin. The use of the above bisphenol type epoxy resin is desirable in that the viscosity can be adjusted by selecting an A type or F type resin without using a diluting solvent, and it is preferable to adjust the viscosity to a lower value. The bisphenol F type epoxy resin is more preferable in that it can be obtained. Further, it is preferable to use the above novolac type epoxy resin because the resin has high strength, excellent heat resistance and chemical resistance, and is less likely to be thermally decomposed. Further, as the novolac type epoxy resin, a phenol novolac type epoxy resin and a cresol novolac type epoxy resin are desirable.

The bisphenol type epoxy resin and the novolac type epoxy resin are preferably mixed and used. In this case, the mixing ratio of the bisphenol type epoxy resin and the novolac type epoxy resin is preferably 1: 1 to 1: 100. This is because mixing within this range can suppress an increase in viscosity.

Examples of the above-mentioned photosensitive resin include UV-curable resins such as fluorinated epoxy resin and fluorinated epoxy acrylate resin, and specific examples of these are, for example, Optodyne UV-1 manufactured by Daikin Industries, Ltd.
000, Optodyne UV-2000, Optodyne U
V-3000, Optodyne UV-4000 and the like.

The photosensitive resin may be, for example,
The resin etc. which added the photosensitivity to the said thermosetting resin are also mentioned. Specifically, for example, the one in which the thermosetting group of the thermosetting resin is (meth) acrylated by using (meth) acrylic acid or the like can be mentioned. Among these, the (meth) acrylate of the epoxy resin is preferable, and the epoxy resin having two or more epoxy groups in one molecule is more preferable.
Examples of the photosensitive resin also include acrylic resin and the like. These photosensitive resins may be used alone or in combination of two or more.

The above-mentioned adhesive may optionally contain additives such as a curing agent, resin particles, inorganic particles, particles such as metal particles, a brightening agent, a reaction stabilizer and a photopolymerization agent. By including these additives, it is possible to improve the fluidity and adjust the degree of curing. The curing agent is not particularly limited, and commonly used curing agents can be used, and specific examples thereof include an imidazole curing agent and an amine curing agent.

Examples of the above resin particles include those made of thermosetting resin, thermoplastic resin and the like. Specifically, for example, amino resin (melamine resin, urea resin,
(Guanamine resin), epoxy resin, phenol resin, phenoxy resin, polyimide resin, polyphenylene resin,
Examples include polyolefin resins, fluororesins, bismaleimide-triazine resins, and the like. These may be used alone or in combination of two or more. Also,
As the resin particles, particles made of rubber such as acrylonitrile-butadiene rubber and polychloroprene rubber can also be used.

Examples of the inorganic particles include aluminum compounds such as alumina and aluminum hydroxide, calcium compounds such as calcium carbonate and calcium hydroxide, potassium compounds such as potassium carbonate, magnesium compounds such as magnesia, dolomite, and basic magnesium carbonate. Examples thereof include those made of silicon compounds such as silica and zeolite. These may be used alone or in combination of two or more, and as the above-mentioned inorganic particles, phosphorus or a phosphorus compound may be used.

Examples of the metal particles include gold, silver,
Examples include copper, tin, zinc, stainless steel, aluminum, nickel, iron and lead. These may be used alone or in combination of two or more. By including these particles, adjustment of the thermal expansion coefficient and improvement of flame retardancy can be achieved.

The adhesive may contain a solvent, but it is desirable that the adhesive does not contain any solvent. This is because bubbles are less likely to occur in the adhesive containing no solvent after the curing treatment. When a solvent is included, the solvent is
For example, NMP (normal methylpyrrolidone), DMD
Examples thereof include G (diethylene glycol dimethyl ether), glycerin, cyclohexanol, cyclohexanone, methylcellosolve, methylcellosolve acetate, methanol, ethanol, butanol, propanol and the like.

Next, a method of manufacturing the optical fiber array of the present invention will be described. Here, a method for manufacturing an optical fiber array using an optical fiber ribbon will be described.
(1) To manufacture the optical fiber array, first, a plurality of grooves are formed in the substrate. The material of the substrate is not particularly limited as long as it is excellent in flatness when subjected to outer shape processing, easily subjected to mirror surface processing, and excellent in shape retention. Specifically, for example, silicon, silicon carbide,
Alumina, aluminum nitride, mullite, ceramic,
Inorganic materials such as gallium arsenide, zirconia, quartz and glass; metallic materials such as copper, iron and nickel; thermosetting resins, thermoplastic resins, photosensitive resins, organic materials such as composites thereof, and organic materials thereof Examples include those impregnated with a reinforcing material such as glass fiber.

Among these, an inorganic material is preferable because it is less likely to expand or contract (deform) due to heat or humidity and has excellent mechanical strength. In the case of a substrate made of an inorganic material having such characteristics, when an optical fiber is housed, deformation or waviness of the optical fiber is unlikely to occur, and inconvenience particularly occurs when transmitting an optical signal through the optical fiber. Because it is difficult to do.

As a method of forming the groove in the above-mentioned substrate, for example, a method of passing through the following steps (i) to (vi) can be used. 3A to 3F are cross-sectional views showing an example of a method of forming a groove on a substrate.

(I) First, the mask layer 15 is formed on the substrate 151.
2 (152a, 152b) are formed (see FIG. 3A). The number of mask layers is not limited to two as shown in FIG. 4 and may be one or three or more.

As a method of forming the mask layer 152,
For example, a method of forming a thin film by sputtering, CVD, plating or the like, a method of forming an oxide film by thermal oxidation or the like, a method combining these, or the like can be used. Among these, for example, when forming a mask layer on a substrate made of silicon, first an oxide film (SiO ₂ film) is formed by thermal oxidation, and then a thin film is formed on this oxide film by CVD. A method of forming is desirable. By forming such a mask layer, it is possible to form a mask having an arbitrary shape by subjecting an arbitrary portion to etching treatment in a later step.

(Ii) Next, a resist resin layer 154 is formed on the mask layer 152 (see FIG. 3B). Specifically, a method in which a resist resin composition whose viscosity has been adjusted in advance is applied by a spin coater, a curtain coater, a roll coater, printing, or the like, or a resist resin film which has been formed into a film shape in advance is attached. A method of attaching can be used.

The resin composition for resist and the resin film for resist are composed of, for example, a resin component and a curing agent, particles, a rubber component, an additive, a reaction stabilizer, a solvent and the like which are blended as necessary. There are things. Examples of the resin component include a thermosetting resin, a thermoplastic resin, a photosensitive resin, a resin in which a part of the thermosetting resin is replaced with a photosensitive group, a composite resin of these, and the like.

Specifically, for example, thermosetting resins such as epoxy resin, phenol resin, polyimide resin, bismaleimide resin, polyphenylene resin, polyolefin resin, and fluororesin; thermosetting groups of these thermosetting resins (for example, , (Epoxy group in epoxy resin) is reacted with methacrylic acid or acrylic acid to form an acrylic group (photosensitive group).
Resins provided with: thermoplastics such as phenoxy resin, polyether sulfone (PES), polysulfone (PSF), polyphenylene sulfone (PPS), polyphenylene sulfide (PPES), polyphenyl ether (PPE), and polyetherimide (PI) Resin: Acrylic resin, photosensitive resin such as ultraviolet curable resin, and the like. Among these, epoxy resin, phenol resin, polyimide resin, acrylic resin, and ultraviolet curable resin are preferable. This is because when the mask layer under the resist resin layer is treated with an etching solution in a later step, the resistance to the etching solution is excellent. Examples of the curing agent include imidazole curing agents, amine curing agents, acid anhydride curing agents, and the like.

The resist resin layer has a thickness of 10
˜50 μm is desirable. The resist resin layer may be in a cured state or a semi-cured state. Specifically, for example, in the case where the resist resin layer in the portion corresponding to the groove to be formed on the substrate is removed by exposure and development in a later step, it is preferably in a semi-cured state. When the resist resin layer corresponding to the groove is removed, it may be in a cured state or a semi-cured state. In the case of forming a resist resin layer in a completely cured state or a semi-cured state, it is desirable to perform the curing treatment by heating at 70 to 200 ° C, for example. Moreover, you may perform step hardening which changes a heating temperature step by step.

(Iii) Next, a part of the resist resin layer 154, that is, a part corresponding to the groove formed in the substrate 151 is removed to obtain an etching resist 155 (FIG. 3).
(See (c)). The resist resin layer 154 can be removed by, for example, exposure and development treatment. Specifically, for example, a mask is placed on the semi-cured resin layer for resist, an exposure process is performed, and then a development process using a chemical solution such as an alkaline solution or an organic solvent is performed. The developing treatment can be performed by immersing the substrate having the resin layer for resist in the chemical solution or spraying the chemical solution. As the mask, it is possible to use a mask in which a groove pattern is drawn in a portion corresponding to the removed portion of the resist resin layer.

The removal of the resist resin layer 154 is
Alternatively, laser processing may be used. Examples of the laser used for the laser processing include carbon dioxide gas laser, excimer laser, UV laser, and YAG laser.
These lasers may be selectively used in consideration of the shape of the removed portion of the resist resin layer, the composition of the resist resin layer, and the like. By adjusting the shape of the etching resist formed in this step, it is possible to adjust the shape of the groove formed through the subsequent steps.

(Iv) Next, the mask layer 152 exposed in the portion where the etching resist 155 is not formed is removed, and the substrate 151 is removed.
A mask 156 is formed by exposing the portions where the grooves are formed (see FIG. 3D). The mask layer 152 can be removed by, for example, plasma treatment using oxygen plasma or nitrogen plasma, corona treatment, or dry etching treatment such as reverse sputtering. Specifically, for example,
This can be performed by irradiating the mask layer with oxygen plasma under vacuum or reduced pressure. By performing such a dry etching process, it is possible to selectively remove only the mask layer in the resist non-forming portion without causing damage or deformation of the etching resist.

The mask layer 152 can be removed by, for example,
It is also performed by immersing the substrate on which the mask layer 152 is formed in an etching solution or an acid solution, immersing the substrate in the solution and performing ultrasonic treatment, or spraying the etching solution or the acid solution on the mask layer. be able to. The removal method to be specifically selected may be appropriately determined in consideration of the material and thickness of the mask layer. For example, when the mask layer is made of an oxide film, plasma treatment or etching solution is used. When the mask layer is made of a metal layer, reverse sputtering or a treatment with an etching solution may be selected.

(V) Next, the etching resist 15
5 is peeled off and removed (see FIG. 3E). The removal of the etching resist 155 should be carried out using an alkaline solution such as NaOH, KOH, an acid solution such as sulfuric acid, acetic acid, carbonic acid, alcohols such as methanol and ethanol, amines, ketones, organic solvents such as acetone, and the like. You can As a result, only the mask 156 having the opening corresponding to the portion where the groove is formed is formed on the substrate 151.

(Vi) Next, a groove 157 is formed in the substrate 151 (see FIG. 3 (f)). The groove 157 is, for example, the substrate 1
It can be formed by spraying an etching solution on 51 through the mask 156 or by immersing the substrate 151 on which the mask 156 is formed in the etching solution. Examples of the etching solution include NaOH and K
An alkali such as OH, an acid such as nitric acid, phosphoric acid, sulfuric acid, a fluorine-based compound such as hydrogen fluoride or bromine fluoride, a halide, a hydrogen peroxide solution, an alcohol such as methanol or ethanol, or the like can be used. When the groove is formed by using these etching solutions, the cross-sectional shape of the groove is V-shaped, inverted trapezoidal shape, rectangular shape, or a combination thereof.

The concentration of the etching solution is preferably 10 to 50% by weight. If the concentration is less than 10% by weight, the etching process may take a long time, while if it exceeds 50% by weight, the etching rate hardly changes.
The temperature of the etching solution is preferably 20 to 90 ° C., and the etching rate is preferably 0.5 to 5.0 μm / min. If the temperature of the etching solution is lower than 20 ° C., the etching may not be sufficiently performed, and even if the temperature of the etching solution exceeds 90 ° C., the etching amount is hardly changed, and the safety during the work is lowered.

Here, when a groove is formed in a substrate whose material is silicon or gallium arsenide, it is desirable to perform an etching process using an alkaline solution such as KOH. When a substrate made of silicon or gallium arsenide is subjected to etching treatment, a groove having a desired shape is formed by selecting an appropriate etching surface, type of etching solution, and shape of the etching resist non-forming portion. be able to.

That is, when a silicon substrate is etched using an etching solution containing KOH, the (100) plane of the silicon substrate is preferentially etched as compared with the (111) plane and the (110) plane, and each crystal is crystallized. Since the etching rate ratio of the surface is almost constant, a groove having a desired shape can be formed. Specifically, when the (100) surface of the silicon substrate is subjected to etching treatment, it is possible to form a groove having a V-shaped or inverted trapezoidal cross section.
When the (110) plane is subjected to etching treatment, a groove having a rectangular cross section can be formed.

When the gallium arsenide substrate is etched using an etching solution containing KOH, (11
1) The slowest etching rate of Ga surface is (111) A
By utilizing the fact that the s-plane has the highest etching rate, it is possible to form a groove having a desired shape.

When the etching treatment is performed in this step, a surfactant or the like may be added to the etching solution. When the foaming occurs violently during the etching process, irregularities may be formed on the etching surface due to the foaming, but by adding a surfactant, the foaming during the etching process can be suppressed. Also,
The etching process may be performed while applying ultrasonic waves. This is because foaming can also be suppressed by applying ultrasonic waves.

When the substrate is dipped in the etching solution to perform the etching process, the etching process may be performed while the substrate is swung or the etching solution is stirred. Through the steps (i) to (vi), a groove having a desired shape can be formed on the substrate.

Further, in the step (1), it is desirable to form a groove in the substrate and to form a coating resin layer holding portion for holding the optical fiber or the optical fiber ribbon together with the coating resin layer. The method for forming the coated resin layer holding portion is not particularly limited, and examples thereof include a method using a device equipped with a diamond blade. Further, the formation of the coating resin layer holding portion may be performed once or may be performed twice or more.

Further, when the coated resin layer holding portion is formed, the bottom surface of the coated resin layer holding portion may have irregularities. In this case, a polishing process may be performed to flatten the unevenness, but if the unevenness is such that the optical fiber ribbon is greatly inclined when the optical fiber ribbon or the like is stored, the polishing process is particularly performed. It is desirable to leave it as it is. This is because when the coating resin layer holding portion holds the coating resin layer via the adhesive layer, the adhesion between the coating resin layer holding portion and the adhesive improves due to the anchor effect. Further, when forming the coating resin layer holding portion here, a plurality of holding surfaces having different heights are formed in the coating resin layer holding portion so as to follow the shape of the optical fiber ribbon to be held. Good. Also, on the substrate,
In the case of forming a concave portion that can accommodate the optical fiber together with the surrounding coating resin layer instead of the covering resin layer holding portion, the concave portion may be formed by cutting the substrate here. .

(2) Here, apart from the production of the substrate, an optical fiber ribbon in which a part of the coating resin layer is removed and the optical fiber is exposed is produced. Here, the coating resin layer to be removed may be the coating resin layer at one end of the optical fiber ribbon or may be a portion of the coating resin layer other than both ends of the optical fiber ribbon. It is desirable that it is a part of the coating resin layer other than both end portions of. In the optical fiber ribbon from which a part of the coating resin layer other than the both ends is removed, since both ends thereof are fixed by the coating resin layer, variation in the axial direction of the optical fiber is less likely to occur, and the post-process Therefore, it is suitable for being stored in the substrate.

The above-mentioned coating resin layer is removed by, for example, a mechanical removal method using a tool such as a stripper, or a chemical removal method by dissolving the coating resin layer using an organic solvent. be able to. Further, a method of removing by irradiation with laser light can also be used.

A method of removing the coating resin layer by irradiating laser light will be described below. The coating resin layer is removed, for example, by horizontally fixing the optical fiber ribbon on a support such as a copper clad laminate and then irradiating it with laser light.

In this case, first, laser light is emitted from one direction perpendicular to the main surface of the optical fiber ribbon, and then laser light is emitted from a direction opposite to the one direction perpendicular to the main surface of the optical fiber ribbon. Irradiation is desirable. If the laser light is irradiated only from one direction perpendicular to the main surface of the optical fiber ribbon, the coating resin layer in the shadow of the optical fiber cannot be removed sufficiently, and the coating resin layer in this portion cannot be completely removed. In order to remove it, it is necessary to irradiate a high-power laser beam for a long time, which increases the risk of damaging the surface of the optical fiber and is economically disadvantageous. On the other hand, in the case of irradiating the laser beam by the method described above, the coating resin layer can be removed reliably and efficiently,
Further, the shape of the coating resin layer after the removal, particularly the shape of the end surface of the non-removed portion of the coating resin layer can be controlled with high accuracy.

Irradiation of the above laser light can be performed using, for example, a CO ₂ laser, an excimer laser, or the like. Of these, it is desirable to use a CO ₂ laser. This is because the optical fiber (clad) is less likely to be damaged and only the coating resin layer in a desired portion can be removed. Incidentally, even when peeling the coating resin layer of the silica-based optical fiber using an excimer laser does not cause a particularly large problem, compared to the carbon dioxide laser, running cost is low, after peeling the coating resin layer, Carbide of the coating resin may remain on the surface of the optical fiber.

When the optical fiber ribbon is irradiated with the laser light using the CO ₂ laser, the laser light may be continuously irradiated, but intermittent irradiation (hereinafter, referred to as pulse irradiation) is desirable. . In the case of pulse irradiation, the output can be increased as compared with the case of continuous irradiation, so that the coating resin layer can be efficiently removed,
Further, since the coating resin layer is gradually removed, the processing can be performed while confirming the removed state, and the possibility of damaging the optical fiber (clad) is further reduced.

When the CO ₂ laser is used to pulse-irradiate the laser beam, the pulse width is 10 to 100.
It is preferably μs. If the pulse width is less than 10 μs, it is necessary to increase the number of times of laser light irradiation in order to sufficiently remove the coating resin layer, which is not very efficient. On the other hand, if the pulse width exceeds 100 μs, the optical fiber (clad ) May be damaged.

When the CO ₂ laser is used to irradiate the laser beam, the irradiation conditions may be appropriately selected in consideration of the material, thickness, etc. of the coating resin layer, but normally the integrated energy is It is desirable that it is 2.0 to 9.0 mJ / cm ² . If the cumulative energy is less than 2.0 mJ / cm ² , the coating resin layer may not be completely removed, while the cumulative energy is 9.0 mJ / cm ^2.
If it exceeds, the optical fiber (clad) may be damaged.

The number of times of laser light irradiation may be appropriately selected according to the material and thickness of the coating resin layer, the output of the CO ₂ laser, and the like. For example, the clad diameter is 125 μm.
In the case of irradiating the optical fiber ribbon having the shortest distance between outer edges of the adjacent clads (hereinafter referred to as the clad interval) of 250 μm with the laser beam with the pulse width and the accumulated energy in the above range, about 3 to 8 times. Is desirable. If the number of times of irradiation is less than 3 times, it may be difficult to completely remove the coating resin layer, while if it exceeds 8 times, one main surface of the optical fiber ribbon is irradiated with laser light. Most of the coating resin layer is removed on the optical fiber ribbon, and the optical fiber is scattered before the laser beam is irradiated on the surface opposite to the one main surface of the optical fiber ribbon. Can be difficult.

FIG. 4A is a front view schematically showing an example of a method of peeling the coating resin layer of the optical fiber ribbon by irradiating it with a laser beam, and FIG. 4B is a side view thereof. . As shown in FIGS. 4A and 4B, when the coating resin layer is peeled off by irradiating the laser beam, the laser irradiation device 20 is arranged above one main surface of the optical fiber ribbon 110, and A laser beam 21 perpendicular to one main surface of the optical fiber ribbon 110 is emitted from the irradiation device 20 toward the optical fiber ribbon 110, and the laser beam 2 is emitted.
The optical fiber ribbon 110 is moved in the width direction while removing the coating resin layer in the portion irradiated with 1.

In this case, first, the optical fiber ribbon 110
After removing the coating resin layer having a thickness of about 1/2, it is desirable to reverse the optical fiber ribbon 110 and irradiate the laser beam 21 to remove the remaining coating resin layer. If there are too many coating resin layers to be removed initially, the respective optical fibers 115 will come apart at that time, and then the optical fiber ribbon 110 will be inverted, and then the laser light 2 will be removed again.
When irradiating 1, the laser beam 21 may be difficult to irradiate accurately, and the irradiation amount of the laser beam directly irradiating the optical fiber 115 increases, which may damage the optical fiber 115. It will be higher.

The movement of the optical fiber ribbon in the width direction is preferably performed by the radius of the laser irradiation area each time the coating resin layer of about ¼ of the thickness of the optical fiber ribbon 110 is removed. By moving the optical fiber ribbon in this manner, the region initially irradiated with the laser light 21 and
Next, the coating resin layer in the area overlapping with the area irradiated with the laser light 21 is 1 / thick of the thickness of the optical fiber ribbon 110.
This is because about 2 is removed, and the coating resin layer having such a thickness can be reliably removed over the entire width direction of the optical fiber ribbon 110. The coating resin layer at the right end in FIG. 4A (the portion that is initially irradiated with laser light) is irradiated by the radius of the irradiation area of the laser light, and the coating is about 1/4 of the thickness of the optical fiber ribbon. It is only necessary to remove the resin layer.

Further, after removing the coating resin layer of about ½ of the thickness of the optical fiber ribbon in the width direction by the above-mentioned method,
By repeating the step of shifting the optical fiber ribbon 110 in the axial direction and removing the coating resin layer having a thickness of about ½ in the width direction, the coating resin layer in a region wider than the irradiation diameter of the laser light 21. Can be removed. Then, after the optical fiber ribbon 110 is turned over, the remaining coating resin layer is similarly removed, whereby the coating resin layer in a region wider than the irradiation diameter of the laser light 21 can be completely removed.

In this case, it is desirable to control the laser irradiation area so that the previously removed coating resin layer area and the subsequent laser light irradiation area do not overlap. When the coating resin layer region removed earlier and the laser irradiation region later overlap,
This is because the coating resin layer in the overlapping portion may be excessively removed, and the optical fiber may be disjointed.
Further, the control of the laser irradiation region may be performed by aligning the optical fiber ribbon, or may be performed by irradiating the laser beam through a mask, a lens, or the like,
Further, these may be combined.

Although the method of removing the coating resin layer while moving the optical fiber ribbon has been described here, the coating resin layer may be removed while moving the laser irradiation device. Further, depending on the size of the area where the coating resin layer is removed, the irradiation diameter of the laser light, and the like, the entire area where the coating resin layer is removed may be irradiated with the laser light at once.

After removing the coating resin layer, it is desirable to form a roughened surface on the surface of the optical fiber by the method described above. When a roughened surface is formed on the surface of the optical fiber, the degree of inflow of the uncured adhesive due to the surface tension is substantially uniform when the uncured adhesive is poured from the side surface of the substrate in a later step. As a result, the uncured adhesive can be reliably poured into the gap between the groove and the optical fiber.

(3) Next, after the exposed optical fiber of the optical fiber ribbon is housed in the groove of the substrate manufactured in the above step (1), the optical fiber is fixed to the substrate with an adhesive. Here, when storing the optical fiber ribbon from which the coating resin layer at one end is removed, the optical fiber ribbon may be stored so that the end face of each optical fiber and the side face of the substrate are aligned, or each optical fiber is placed on the substrate. You may store so that it may protrude from the side surface of a certain length.

When the optical fiber ribbon from which a part of the coating resin layer other than both ends is removed is housed, the optical fiber ribbon which is not housed in the substrate after housing the optical fiber ribbon is housed. Will be cut off at one end. In addition, when cutting and removing one end of the optical fiber ribbon, it may be cut and removed so that the end face of each optical fiber and the side surface of the substrate are aligned, or each optical fiber has a certain length from the side surface of the substrate. You may cut and remove so that it may protrude. The cutting and removal of the optical fiber ribbon can be performed by cutting using a cutter or the like. Alternatively, mechanical polishing may be performed.

Further, in the step (1), when the coating resin layer holding portion for holding the optical fiber ribbon together with the coating resin layer is formed, the optical fiber is housed in the groove in this step, and The optical fiber ribbon together with the coating resin layer is placed on the coating resin layer holder. Further, when a concave portion is formed on the substrate instead of the coating resin layer holding portion, the optical fiber ribbon is housed in the concave portion together with the coating resin layer.

In the step (1), when the groove is formed by going through the steps (i) to (vi), the mask is formed on the substrate, so that the optical Strictly speaking, the portion for accommodating the fiber is a portion where the mask non-formation portion and the groove provided on the substrate are combined, but in the present specification, after the groove is formed on the substrate, the both are combined. The part is called a groove.

In this way, after the exposed optical fiber of the optical fiber ribbon is housed in the groove, the optical fiber is fixed. Specifically, for example, an uncured adhesive is poured from the end of the groove, and then the adhesive is cured to fix the optical fiber. In addition, when the coating resin layer holding portion is formed on the substrate and the optical fiber ribbon is placed on the coating resin layer holding portion together with the coating resin layer, an adhesive is also applied around the coating resin layer to form the coating resin layer. It is desirable to fix the layer to the coating resin layer holding portion. It should be noted that before storing the optical fiber, an adhesive may be poured into the groove or the like in advance, and after storing the optical fiber, the adhesive may be cured to fix the optical fiber.

The above-mentioned adhesive is cured by, for example, 80 to 25.
It can be performed by heating at 0 ° C. The adhesive containing the photosensitive resin may be cured by irradiating it with ultraviolet rays or infrared rays.

(4) Next, a lid having a concave portion for accommodating a part of the optical fiber is attached to the substrate on which the optical fiber is accommodated and fixed. Here, the attachment of the lid on the substrate is usually performed via an adhesive layer. Therefore, an uncured adhesive is applied to the outer edge portion of the substrate and / or the outer edge portion of the lid portion in advance, and the substrate and the lid portion are interposed via the adhesive layer formed by curing the uncured adhesive agent. And close contact. The lid can be formed by cutting a plate-like body made of an inorganic material or a metal material.

After the lid is formed, an uncured adhesive is poured into the gap between the lid and the optical fiber, and the adhesive is cured to fix the lid and the optical fiber. Is desirable. Further, after housing the optical fiber in the groove of the substrate and before fixing the optical fiber in the groove, the lid is formed first, and then the gap between the groove and the optical fiber, and the recess and the optical fiber It is desirable to pour uncured adhesive into the gap at the same time. This is because when the lid is placed on the adhesive after applying the adhesive, air easily enters between the adhesive and the lid. Further, when the adhesive made of a photosensitive resin is used, since ultraviolet rays and infrared rays are radiated through the lid,
As described above, it is desirable that the material of the lid portion be a material such as quartz or glass that transmits ultraviolet rays and infrared rays.

Thereafter, the end faces of the substrate, the optical fiber and the lid are subjected to a polishing treatment so that these end faces are aligned and the end faces of the optical fiber array are inclined.
Here, since the lid is formed with a concave portion for accommodating a part of the optical fiber at a time, the vicinity of the side surface of the optical fiber array is largely scraped off, or a part of the end surface of the optical fiber is cut. Is not obliquely polished, so that no inconvenience occurs in the manufactured optical fiber array.

In the step (3), the optical fiber ribbon from which a part of the coating resin layer other than both ends thereof is removed is housed, and the part of the optical fiber ribbon which is not housed in the substrate is cut and removed. In this case, this cutting and removal may be performed after forming the lid portion and before performing the polishing treatment.

Through the above steps, the optical fiber array of the present invention can be manufactured. Although the method of manufacturing the optical fiber array using the optical fiber ribbon has been described here, the optical fiber array of the present invention can be manufactured by using a single-core optical fiber or a laminated optical fiber ribbon. be able to.

Specifically, when manufacturing an optical fiber array using a single-core optical fiber, for example, a plurality of optical fibers from which the coating resin layer at one end is peeled off are arranged in parallel using an aligner. After aligning, in the step (3) above, the substrate is stored in the substrate while being held by the aligner, and then the optical fiber is fixed and the lid is formed using the same method as described above. The optical fiber array can be manufactured by.

When an optical fiber array is manufactured using the laminated optical fiber ribbon, for example, a laminated optical fiber ribbon 300 in which a part of the coating resin layer is removed is prepared as shown in FIG. After that, the optical fiber array can be manufactured by housing and fixing this laminated optical fiber ribbon on the substrate. FIG. 5 is a partial perspective view schematically showing an embodiment of the laminated optical fiber ribbon.

As shown in FIG. 5, the laminated optical fiber ribbon 300 has a part of the optical fiber 345a other than both ends thereof.
Between the exposed optical fibers 345a of the exposed second optical fiber ribbon (lower optical fiber ribbon) 340,
The first optical fiber ribbon 330 and the second optical fiber 330 are arranged so that the exposed optical fiber 335a of the first optical fiber ribbon (upper optical fiber ribbon) 330 with the optical fiber 335a at one end thereof exposed. Ribbon 340
And are stacked.

In the laminated optical fiber ribbon 300,
The exposed optical fibers 335a, 345a are arranged so that the exposed optical fibers 335a, 345a are arranged at the same height.
Each of 5a is bent at a part thereof. Thus, optical fiber 335a and optical fiber 345a
By arranging the same at the same height, it becomes a shape suitable for being housed in the groove of the substrate.

In the laminated optical fiber ribbon 300,
The exposed optical fiber 3 of the first optical fiber ribbon 330
35a and a part of each of the exposed optical fibers 345a of the second optical fiber ribbon 340 are bent, but if both optical fibers can be arranged at the same height, Only the exposed optical fiber of the optical fiber ribbon may be bent, or only the exposed optical fiber of the second optical fiber ribbon may be bent.

In the laminated optical fiber ribbon 300, it is desirable that the first optical fiber ribbon 330 and the second optical fiber ribbon are fixed to each other with an adhesive. Note that in the laminated optical fiber ribbon 300 shown in FIG. 5, eight optical fibers are arranged at the same height, but the number of optical fibers in the laminated optical fiber ribbon is not limited to eight, and seven optical fibers are provided. May be less than or equal to 9
It may be more than a book. Further, the number of optical fibers in each of the first and second optical fiber ribbons is as shown in FIG.
It is desirable that the number of optical fiber ribbons is the same as that of the optical fiber ribbons shown in (1), the number of the first optical fiber ribbons is one more, or that of the second optical fiber ribbons is one more. This is because in such a case, the optical fibers can be arranged at the highest density.

In the production of the laminated optical fiber ribbon, for example, first, the coating resin layer at one end of the optical fiber ribbon is
As described above, a first optical fiber ribbon is produced by removing it by a method using a tool, a method of dissolving with an organic solvent, or the like, and separately from this, using the same method for removing the coating resin layer as described above. , A second optical fiber ribbon is produced by removing a part of the coating resin layer other than both ends of the optical fiber ribbon, and then, after bending a part of the optical fiber, both optical fibers are alternately It can be performed by stacking the first and second optical fiber ribbons with an adhesive so that they are evenly spaced apart. The coating resin layer may be removed by using a method of irradiating laser light.

As a method for accommodating and fixing such a laminated optical fiber ribbon on the substrate, the same method as the method used in the step (3) can be used. Even when an optical fiber array is manufactured using the laminated optical fiber ribbon, after the laminated optical fiber ribbon is housed and fixed in the substrate, the second optical fiber ribbon is cut off and the end face of the optical fiber is removed. And the like.

[0108]

The present invention will be described in more detail below.

(Example 1) A. Fabrication of an optical fiber ribbon from which a part of the coating resin layer has been removed.
Optical fiber ribbons (Sumitomo Electric Industrial Co., Ltd.) in which eight fibers of 50 μm are arranged in parallel, and a coating resin layer (primary coating layer 113 and secondary coating layer 114) made of an acrylate-based ultraviolet curable resin is coated around the optical fibers. Made),
A coating resin layer (primary coating layer and secondary coating layer) at a portion 5 to 50 mm from one end of this optical fiber ribbon
Was peeled by the following method (see FIG. 6A).

That is, first, the above optical fiber ribbon was fixed on a copper clad laminate, and then laser light was irradiated under the following conditions using a pulse oscillation type CO ₂ laser irradiation device (manufactured by Mitsubishi Electric Corporation), and then The step of displacing the irradiation position of the laser light by the radius of the irradiation diameter (200 μm) and irradiating the laser light again under the following conditions is repeated to remove about 1/2 of the thickness of the coating resin layer. Then, after inverting the optical fiber ribbon, the remaining about 1/2 coating resin layer was removed in the same manner as above to expose the optical fiber. Note that FIG.
In the optical fiber ribbon shown in Fig. 4, four optical fibers are arranged in parallel, but this figure is a schematic diagram. In reality, as described above, the optical fiber in which eight optical fibers are arranged in parallel is used. A fiber ribbon was used.

[0111]Laser irradiation conditions Laser mask diameter φ5.1mm Lens position 190mm Pulse width 15μs Laser beam irradiation diameter φ400 μm 5 shots Accumulated energy 3.2 mJ / cm^Two

B. Fabrication of lid part A substrate made of quartz glass is subjected to a cutting process using a diamond cutter to form a concave part 161 for accommodating an exposed optical fiber, which is a lid part 160 (see FIG. 7A). ). The recess has a rectangular cross section.

C. Fabrication of optical fiber array (1) Starting from a silicon substrate 151 having a thickness of about 0.7 mm whose surface is polished, a mask layer 152 was formed on this silicon substrate 151 by the following method (FIG. 3). (See (a)). That is, first, the silicon substrate 1
51 in the thermal oxidation furnace with a thickness of 0.04 μm SiO 2
₂ film 152a is formed, and then a Si ₃ N ₄ film 15 having a thickness of 0.1 μm is formed on the SiO ₂ film by using the low pressure CVD method.
By forming 2b, the SiO ₂ film 152a and Si
_A mask layer 152 composed of two layers including the ₃ N ₄ film 152b was formed.

(2) Next, a thickness of 25 is formed on the mask layer 52.
A resin layer for resist 154 was formed by attaching a resin film for resist having a thickness of μm (see FIG. 3B).

(3) Next, the resist resin layer 154 is formed.
Place a mask with a groove pattern drawn on it, 800m
It is exposed to J / cm ² and then developed with an alkaline solution to form an etching resist 15 on the mask layer.
5 was formed (see FIG. 3 (c)).

(4) Next, the etching resist 15
5 Remove the mask layer exposed in the non-formed area by the following method
Then, a mask 156 exposing a part of the substrate 151 is formed.
(See FIG. 3D). That is, first, the exposed S
i_ThreeN_FourDry etching of the film using oxygen plasma
SiO by removing by treatment_TwoExpose the membrane,
Furthermore, this SiO _TwoThe film uses an HF-based etchant
Removed by wet etching process, silicon substrate
Exposed.

(5) Next, the etching resist was stripped off using 10% by weight of NaOH (see FIG. 3E). As a result, on the silicon substrate 151, only the mask 156 having the opening corresponding to the portion where the groove is formed is formed.

(6) Next, the silicon substrate 151 on which the mask 156 is formed is subjected to a KOH concentration of 25% by weight and a liquid temperature of 7%.
8 ° C. etching solution (KOH: 100 g, H ₂ O: 30
0 g) to form eight V grooves having a depth of 90 μm (see FIG. 3 (f)). After that, a coating resin layer holding portion 58 (see FIG. 6A) for holding the optical fiber ribbon together with the coating resin layer was formed on a part of the substrate 51 by performing a cutting process using a diamond cutter. Although only four grooves are formed on the substrate shown in FIG. 6, this drawing is a schematic diagram, and in fact, eight grooves were formed on the substrate as described above.

(7) Next, the exposed portion of the optical fiber 115 of the optical fiber ribbon 110A produced in the above A is
It is placed in the V groove 157 (see FIGS. 6A and 6B), and the lid 160 manufactured in the above B is further placed on the substrate 151 via an adhesive (UV-3000, manufactured by Daikin Industries, Ltd.). It was attached (see FIG. 7 (a)). The adhesive was previously applied to the outer edge of the lid. Furthermore, an adhesive (UV-300 manufactured by Daikin Industries, Ltd., manufactured by Daikin Industries, Ltd.)
0) was poured. Further, the adhesive (UV-30) is also formed around the coating resin layer placed on the coating resin layer holding portion 158.
00) was applied.

Next, an ultraviolet ray of 10 J / cm ² is irradiated from the upper portion of the substrate 151 provided with the lid portion 160 with a high pressure mercury lamp, and then the adhesive is heated at 60 ° C. for 1 hour. It was completely cured.

(8) Next, the coating resin layer 114a not housed in the substrate at one end of the optical fiber ribbon 110A,
The optical fiber covered with this coating resin layer was cut and removed by a diamond cutter, and further, polishing treatment was performed so that the end face of the optical fiber and the end faces of the substrate and the lid portion were aligned, to manufacture the optical fiber array 101. (See FIG. 7B). The polishing treatment was performed so that the end faces of the optical fiber, the substrate and the lid portion had an inclination of 8 ° with respect to the bottom face of the substrate.

(Example 2) In the step B of Example 1 (manufacture of the lid), borosilicate glass (Pyrex (R)) was used.
The substrate made of is subjected to a cutting process using a diamond cutter to form a recess 171 for accommodating the exposed optical fibers having different depths, and a recess 172 for accommodating the optical fiber ribbon together with the coating resin layer. A lid portion 170 having the above is manufactured (see FIG. 8A), and the lid portion 170 is attached to the substrate in the step (7) of C of the first embodiment, and the light is emitted in the same manner as in the first embodiment. Fiber array 1
No. 02 was manufactured (see FIG. 8B).

(Example 3) A. Fabrication of laminated optical fiber ribbon from which some coating resin layers have been removed
Optical fiber ribbons (Sumitomo Electric Industrial Co., Ltd.) in which eight (8) m are arranged in parallel and a coating resin layer (primary coating layer and secondary coating layer) made of an acrylate-based UV-curable resin is coated around the optical fibers. Was prepared, and each of the optical fiber ribbons was subjected to the following processing (i) and (ii).

(I) First, from the one end of the optical fiber,
The coating resin layers (primary coating layer and secondary coating layer) up to mm were removed under the same conditions as in step A of Example 1 to expose the optical fiber.

(Ii) 5 to 50 m from one end of the optical fiber
The optical fiber was exposed by removing the coating resin layer (primary coating layer and secondary coating layer) at the portion m under the same conditions as in step A of Example 1.

(2) Next, the first optical fiber ribbon 330 treated with the above (i) was stacked on the second optical fiber ribbon 340 treated with the above (ii).
Furthermore, the exposed portions 335a, 3a of both optical fibers
Part of each optical fiber was bent so that the heights of 45a were the same, and a laminated optical fiber ribbon 300 was obtained (see FIG. 6).

In this step, when stacking the first optical fiber ribbon 330 on the second optical fiber ribbon 340, after bending a part of the optical fiber, both optical fibers 335 and 345 are They were stacked so that they were alternately arranged at equal intervals. In this step, before stacking the first optical fiber ribbon 330 on the second optical fiber ribbon 340, a part of the upper surface of the secondary coating resin of the second optical fiber ribbon 340 is uncured in advance. Adhesive (not shown)
Was applied, the first optical fiber ribbon 330 was stacked on the second optical fiber ribbon 340 via the adhesive, and then the adhesive was cured to fix them.

B. Fabrication of lid part A lid part was formed in the same manner as in Example 1B, except that the size of the recessed part was such that the exposed optical fiber of the laminated optical fiber ribbon was accommodated.

C. Fabrication of optical fiber array (1) V was applied to the substrate in the same manner as in steps (1) to (6) of C of Example 1 except that the number of grooves to be formed was 16.
A groove was formed, and a coating resin layer holding portion for holding the laminated optical fiber ribbon together with the coating resin layer was formed on a part of the substrate by cutting with a diamond cutter.

(2) Next, the exposed optical fiber of the laminated optical fiber ribbon prepared in the above A is placed in the V groove, and the lid prepared in the above B is attached to the substrate with an adhesive (Daikin Industries Ltd.). UV-3000) manufactured by the same company. The adhesive was previously applied to the outer edge of the lid. Further, an adhesive (made by Daikin Industries, Ltd., UV-3000) is applied to the gap between the groove and the optical fiber and the gap between the lid portion and the optical fiber.
Poured. Further, the adhesive (UV-3000) was applied also around the coating resin layer placed on the coating resin layer holding portion.

Next, ultraviolet rays of 10 J / cm ² were irradiated from the upper part of the substrate provided with the lid using a high pressure mercury lamp, and then the adhesive was completely heated by heating at 60 ° C. for 1 hour. Cured.

(3) Next, the coated resin layer not housed in the substrate at one end of the laminated optical fiber ribbon and the optical fiber covered with this coated resin layer are cut and removed by a diamond cutter, and the optical fiber An optical fiber array was manufactured by performing a polishing treatment so that the end faces of the fibers and the end faces of the substrate and the lid are aligned with each other. The polishing process was performed so that the end faces of the optical fiber, the substrate and the lid portion were inclined by 8 ° with respect to the bottom face of the substrate.

(Embodiment 4) When forming a lid, a substrate made of borosilicate glass (Pyrex (R)) was subjected to a cutting process using a diamond cutter to expose exposed light of different depths. A lid having a concave portion for accommodating the fiber and a concave portion for accommodating the optical fiber ribbon together with the coating resin layer is produced, and the lid portion is used to perform the step (2) of C in Example 3. An optical fiber array was manufactured in the same manner as in Example 3 except that the steps were performed.

With respect to the optical fiber arrays obtained in Examples 1 to 4 and Comparative Examples 1 and 2, a detector was placed on the end face of the optical fiber on the side of the optical fiber array, and a light emitting element was mounted on the other end face of the optical fiber. The storage accuracy of the optical fiber was evaluated by calculating the deviation from the design of the storage position of the optical fiber from the detection position of the light when the light was introduced. Moreover, after pressing the optical fiber array from above with a pressing force of 20 Pa for 20 minutes, the accommodating accuracy of the optical fibers was measured in the same manner as above.

As a result, in the optical fiber arrays of Examples 1 to 4, the deviation from the design of the storage position of the optical fibers was 5% or less both before and after pressing, and the optical fibers were accurately positioned at the predetermined positions. It was stored in. Furthermore, when the optical fiber arrays of Examples 1 to 4 were connected to a light receiving device having 8 or 16 light receiving elements and the coupling loss was measured, the coupling loss was low, and the quality required as a product was obtained. I was fully satisfied.

Further, when the end faces of the optical fiber arrays of Examples 1 to 4 were observed to be polished, the side faces of the end faces were largely scraped off as compared with the central region, and one end face of the optical fiber was cut. The part was never polished at an angle. Further, when the lid of the optical fiber array prepared in Examples 1 to 4 was removed and the surface of the optical fiber was observed with a microscope, no scratches or the like were found on the surface of the optical fiber.

[0137]

As described above, since the optical fiber array of the present invention has the above-described structure, the side surface of the optical fiber array is not largely scraped off during manufacturing as compared with the vicinity of the center of the optical fiber array. In addition, a part of the end face of the optical fiber is not obliquely polished, and the optical signal can be accurately transmitted.

[Brief description of drawings]

FIG. 1A is a partial perspective view schematically showing an example of an optical fiber array of the present invention in which a lid is formed,
(B) is a perspective view showing only the lid part attached to the optical fiber array, and (c) is a sectional view taken along the line AA of (a).

FIG. 2 (a) is a partial perspective view schematically showing an example of an optical fiber array of the present invention using a laminated optical fiber ribbon, and FIG. 2 (b) shows only a lid part attached to the optical fiber array. It is a perspective view shown, (c) is a sectional view on the AA line of (a).

3A to 3F are cross-sectional views showing an example of a method for forming a groove in a substrate.

FIG. 4A is a front view schematically showing an example of a method for peeling a coating resin layer of an optical fiber ribbon, and FIG.
Is a side view thereof.

FIG. 5 is a partial perspective view schematically showing an embodiment of a laminated optical fiber ribbon.

6A and 6B are perspective views schematically showing a part of the manufacturing process of the optical fiber array of the present invention.

7A and 7B are perspective views schematically showing a part of the manufacturing process of the optical fiber array of the present invention.

8A and 8B are perspective views schematically showing a part of the manufacturing process of the optical fiber array of the present invention.

9A to 9D are cross-sectional views schematically showing an example of a manufacturing process of a conventional optical fiber array.

[Explanation of symbols]

135, 235, 245 optical fiber 151,251 substrate 157,257 groove 160, 170 lid 100,200 Fiber Optic Array 110 optical fiber ribbon 210 laminated optical fiber ribbon

Claims (3)

[Claims] 1. A plurality of grooves are formed in a part of the upper surface of the substrate,
An optical fiber array in which an optical fiber is accommodated in the groove via an adhesive, and a lid part for accommodating a part of the optical fiber is attached on the substrate, wherein the substrate of the lid part is An optical fiber array, characterized in that recesses for collectively storing a part of the optical fibers are formed on opposing surfaces. 2. The optical fiber array according to claim 1, wherein the lid is made of an inorganic material or a metal material. 3. The optical fiber array according to claim 2, wherein the inorganic material is ceramic or silicon.