JP2003114363A - Optical fiber array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such an optical fiber array that, since optical fibers are surely fixed to grooves formed on a substrate with an adhesive, the displacement of the optical fibers does not occur. SOLUTION: In the optical fiber array, a plurality of grooves are formed in a part on a substrate and optical fibers are housed in the grooves with an adhesive. A roughened face is formed on the surface of the optical fiber.

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.

[0006]

In such an optical fiber array, when the optical fiber array is connected to an optical element or when an external force is applied to the optical fiber array,
Positional deviation of the optical fiber may occur, resulting in defective connection between the optical fiber array and the optical element such as the light receiving element or the light emitting element. Further, when reliability evaluation is performed using such an optical fiber array, peeling may occur between the surface of the optical fiber and the adhesive. It is considered that such positional deviation of the optical fiber and peeling of the adhesive occur due to insufficient adhesion between the optical fiber and the adhesive.

[0007]

Therefore, the present inventors have
As a result of diligent study, by forming a roughened surface on the surface of the optical fiber, wetting of the uncured adhesive to the optical fiber is improved, so that the gap between the groove and the optical fiber is reliably filled with the adhesive. That is, and because the adhesion between the optical fiber and the adhesive is improved, it was found that peeling does not occur between the surface of the optical fiber and the adhesive even when reliability evaluation is performed, and the optical fiber of the present invention The array was completed.

That is, the optical fiber array of the present invention is
An optical fiber array in which a plurality of grooves are formed in a part of a substrate, and an optical fiber is housed in the groove via an adhesive, and a roughened surface is formed on the surface of the optical fiber. It is characterized by being

In the optical fiber array of the present invention, the average roughness Ra of the roughened surface is preferably 1 to 100 nm. Further, in the optical fiber array, it is preferable that the roughened surface is formed by using a roughening liquid containing fluoride.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An optical fiber array of the present invention is an optical fiber array in which a plurality of grooves are formed in a part of a substrate, and the optical fibers are housed in the grooves via an adhesive. A roughened surface is formed on the surface of the optical fiber.

In the optical fiber array of the present invention, since the roughened surface is formed on the surface of the optical fiber housed in the groove, the optical fiber and the adhesive have excellent adhesiveness, and the optical fiber is surely attached to the substrate. It will be stored and fixed in the formed groove. In addition, by forming a roughened surface on the surface of the optical fiber, wetting of the uncured adhesive with respect to the surface of the optical fiber is improved, and the adhesive is surely filled in the gap between the groove and the optical fiber. Therefore, the optical fiber is securely fixed.

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 the sectional view on the AA line of (a).

As shown in FIG. 1, an optical fiber array 10 is provided.
In No. 0, a plurality of V grooves 157 are formed in parallel on the substrate 151, and each of the V grooves 157 has an optical fiber 115.
Are stored via an adhesive 159. Also, the substrate 1
In addition to the groove 157, a coating resin layer holding portion 158 for holding the optical fiber together with the coating resin layers 113 and 114 around the groove is formed on the 51, and the coating resin layer holding portion 158 is formed. An adhesive layer (not shown) is formed around the coating resin layer 114 placed on the portion 158. 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.

Also, 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 in 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.

FIG. 2 (a) is a partial perspective view schematically showing an example of the optical fiber array of the present invention in which a lid is formed, and FIG. 2 (b) shows only the lid attached to the optical fiber array. It is a perspective view shown, (c) is a sectional view on the AA line of (a). As shown in FIG. 2, the optical fiber array 101 of the present invention is a substrate 1 that accommodates an optical fiber ribbon 110.
A lid portion 160 may be formed on the 51, and the lid portion 160 has a concave portion 161 for accommodating a part of the optical fiber 115 (a portion of the optical fiber that is not accommodated in the groove 157). Are formed. In addition, the recess 16
The adhesive 169 is also filled in the gap between the optical fiber 1 and the optical fiber. Further, the outer edge portion of the substrate 151 and the outer edge portion of the lid 160 are in close contact with each other via an adhesive (not shown).

In such an optical fiber array, a roughened surface (not shown) is formed on the surface of the optical fiber from which the coating resin layers 113 and 114 have been removed. The roughened surface preferably has an average roughness Ra of 1 to 100 nm. When the average roughness Ra is less than 1 nm, the adhesion between the optical fiber and the adhesive is hardly improved, while when the average roughness Ra exceeds 100 nm, the unevenness of the surface of the optical fiber becomes large, so that the roughened surface is large. The shape of the cross section of the optical fiber deviates from the circular shape, the positional deviation of the optical fiber is likely to occur, and the optical signal transmission may be adversely affected. A more desirable average roughness Ra of the roughened surface is 10 to 50 nm.

The method for forming the roughened surface is not particularly limited, but it is preferable that the roughened surface is formed using a roughening liquid 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 is used.
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.

In addition, in the optical fiber arrays 100 and 101 shown in FIGS. 1 and 2, the optical fibers are exposed by removing the coating resin layer at one end on the substrate 151 on which the plurality of V grooves 157 are formed. Optical fiber ribbon 11
0 is stored. The optical fiber ribbon is not particularly limited, and a conventionally known one can be used. For example, the primary coating resin layer 11 is provided around the optical fiber 115 composed of the core 111 and the 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 113 are collectively covered with the secondary coating resin layer 114 in a state where the optical fibers 115 coated with the primary coating resin layer 113 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. By forming a roughened surface on the surface, the adhesiveness with the adhesive is particularly improved, which is suitable for the optical fiber array of the present invention.

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 fiber 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 arrays 100 and 101, the optical fiber ribbon from which the coating resin layer at one end is removed is housed in the substrate, but a plurality of optical fibers are housed in the groove of the substrate. It may be a single-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. 3 is a partial perspective view schematically showing an example of the optical fiber array of the present invention using the laminated optical fiber ribbon. As shown in FIG. 3, the optical fiber array 200
Then, the exposed optical fibers 235 and 245 at one end of the laminated optical fiber ribbon 210 are connected to the V groove 257 on the substrate 251.
And a part of the laminated optical fiber ribbon 210 is held together with the coating resin layer in the coating resin layer holding portion 258. The exposed optical fiber at one end has a roughened surface (not shown) formed on its surface. Further, an adhesive layer (not shown) is formed around the coating resin layer held by the coating resin layer holding portion 258. Further, also in such an optical fiber array using the laminated optical fiber ribbon, a concave portion which can collectively store the laminated optical fiber ribbon together with the coating resin layer on the substrate instead of the coating resin layer holding portion. May be formed.

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 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. 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. 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 adhesive may 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, if necessary. 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 resin particles include thermosetting resins, thermoplastic resins and the like. Specifically, for example, amino resins (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 for 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 and contract (deform) due to heat and 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. 4A to 4F are cross-sectional views showing an example of a method for 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. 4A). 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. 4B). 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 thickness of the resin layer for resist is 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. 4).
(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 resist resin layer 154 is removed by
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 a portion where the groove is formed (see FIG. 4D). 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 and removed (see FIG. 4E). 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.

(F) Next, a groove 157 is formed in the substrate 151 (see FIG. 4F). 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 the groove is formed in the substrate whose material is silicon or gallium arsenide, it is desirable to carry out 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 the respective crystals are 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.

In the step (1), the laminate having the resin layer formed on the base material layer may be used as the substrate, and the groove may be formed in the resin layer of the laminate. Examples of the base material layer include inorganic materials such as silicon, silicon carbide, alumina, aluminum nitride, mullite, ceramics, gallium arsenide, zirconia, quartz, and glass; metal materials such as copper, iron, and nickel; thermosetting resins. , Thermoplastic resin, photosensitive resin,
Examples thereof include organic materials such as these composites and those obtained by impregnating these organic materials with a reinforcing material such as glass fiber.

As the resin layer, for example, at least one of thermosetting resin, thermoplastic resin, photosensitive resin, and resin in which a part of the thermosetting resin is replaced with a photosensitive group is used. Examples of the resin composition include: Examples of the thermosetting resin include epoxy resin, phenol resin, polyimide resin, bismaleimide resin, polyphenylene resin, polyolefin resin, and fluororesin.

Examples of the thermoplastic resin include phenoxy resin and polyether sulfone (PE).
S), polysulfone (PSF), polyphenylene sulfone (PPS), polyphenylene sulfide (PPE)
S), polyphenyl ether (PPE), polyether imide (PI) and the like. Examples of the photosensitive resin include acrylic resin and ultraviolet curable resin. As the resin in which a part of the thermosetting resin is substituted with a photosensitive group, a thermosetting group of the thermosetting resin is reacted with (meth) acrylic acid or the like to give a photosensitive group. Resin etc. are mentioned.

As a method of forming a groove in the laminate composed of such a base material layer and a resin layer, for example, exposure, development treatment, laser treatment or the like can be used. Specifically, when performing exposure and development processing, for example, after placing a mask on which a pattern corresponding to the groove to be formed is drawn on the resin layer, exposure processing is performed, and then a developing solution is used. A plurality of grooves can be collectively formed in the resin layer by subjecting the resin layer to development processing. When the exposure and development processes are performed, it is desirable that the resin layer before the exposure process is in a semi-cured state, and after the development process, in order to completely cure the resin layer in which the groove is formed, heat treatment or the like is performed. May be given.

When laser processing is performed, the laser may be, for example, carbon dioxide gas laser, excimer laser,
A UV laser, a YAG laser or the like can be used. In the laser treatment, the groove can be formed regardless of the material of the resin layer. When performing the laser treatment, the resin layer before the laser treatment may be in a semi-cured state or a completely cured state.

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.

When the coated resin layer holding portion is formed, the upper 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 holding the optical fiber ribbon or the like, the polishing process is particularly performed. It is desirable to leave it as it is. This is because when the adhesive is applied to the coating resin layer holding portion, the adhesion between the substrate and the adhesive is improved due to the anchor effect. Further, when forming the coated resin layer holding portion here, even if a plurality of holding surfaces having different heights are formed in the coated resin layer holding portion so as to follow the shape of the optical fiber ribbon or the like to be held. Good. Further, in the case of forming a recess on the substrate, instead of the coating resin layer holding portion, which can accommodate the optical fiber together with the surrounding coating resin layer, the substrate may be subjected to a cutting process by cutting the substrate. The recess may be formed.

(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 such an optical fiber ribbon from which a part of the coating resin layer other than both ends is removed, both ends of the exposed optical fiber are fixed, so that variation in the axial direction of the optical fiber is less likely to occur, and in a post-process. This is because it is suitable for being stored in the substrate.

The above-mentioned coating resin layer can be removed, for example, by a mechanical removal method using a coating resin peeling device such as a stripper, or a chemical removal method by dissolving the coating resin layer using an organic solvent. Etc. can be used. Alternatively, a method of removing by irradiation with laser light may be used.

A method of removing the coating resin layer by irradiating with 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 irradiated from one direction perpendicular to the main surface of the optical fiber ribbon, and then laser light is irradiated 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 by using the CO ₂ laser, the laser light may be continuously irradiated, but it is preferable that the laser light is intermittently irradiated (hereinafter referred to as pulse irradiation). . 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. 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.
When irradiating an optical fiber ribbon having a shortest distance between outer edges of adjacent clads (hereinafter also referred to as a clad interval) of 250 μm with a laser beam with a pulse width and integrated energy in the above range, 3 to 8 It is desirable to be about once. If the number of irradiations is less than 3, it may be difficult to completely remove the coating resin layer, while 8
Beyond the number of times, most of the coating resin layer is removed when the main surface of the optical fiber ribbon is irradiated with laser light, and before the main surface of the optical fiber ribbon is irradiated with laser light. The optical fibers may come apart, and it may be difficult to irradiate the opposite surface with laser light.

FIG. 5 (a) is a front view schematically showing an example of such a processing method of the present invention, and FIG. 5 (b) is a side view thereof. As shown in FIGS. 5A and 5B, in the processing method of the present invention, the laser irradiation device 20 is arranged above one main surface of the optical fiber ribbon 110, and the laser irradiation device 20 moves from the optical fiber ribbon 110 to the optical fiber ribbon 110. Toward the main surface of the optical fiber ribbon 110, the laser light 21 perpendicular to the main surface is irradiated to remove the coating resin layer at the portion irradiated with the laser light 21, while the optical fiber ribbon 110 is moved in the width direction. To move.

Further, in the processing method of the present invention, after first removing the coating resin layer of about 1/2 the thickness of the optical fiber ribbon 110, the optical fiber ribbon 110 is inverted and the laser beam 21 is irradiated. It is desirable 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 be scattered at that point, and then, after inverting the optical fiber ribbon 110, when irradiating the laser beam 21 again. , It may be difficult to accurately irradiate the laser light 21,
In addition, the irradiation amount of the laser light directly applied to the optical fiber 115 is increased, and the possibility of damaging the optical fiber 115 is further increased.

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. Note that the coating resin layer at the right end in FIG. 5A (the portion where the laser light is first irradiated) 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.

After removing the coating resin layer of about 1/2 the thickness of the optical fiber ribbon in the width direction by the above 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.

(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.

Further, when the optical fiber ribbon from which a part of the coating resin layer other than both ends thereof is removed is housed, the optical fiber ribbon which has not been housed in the substrate after housing the optical fiber ribbon. 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.

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 coating resin layer holding section holds the optical fiber ribbon together with the coating resin layer. 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, and therefore, the light is used in this step. 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. Further, when the coating resin layer holding portion is formed on the substrate and the optical fiber ribbon is held together with the coating resin layer by the coating resin layer holding portion, an adhesive is also applied to the periphery of the coating resin layer to cover the coating resin layer. It is desirable to fix the layers. Further, in the optical fiber array of the present invention, since the roughened surface is formed on the surface of the optical fiber housed in the groove as described above, the degree of inflow of the uncured adhesive due to the surface tension is substantially uniform. Therefore, the uncured adhesive is surely poured into the gap between the groove and the optical fiber. In addition,
The adhesive may be poured into the groove or the like before storing the optical fiber, and the adhesive may be cured after storing 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.

Further, it is preferable that after the exposed optical fiber of the optical fiber ribbon is housed and fixed, a lid portion is formed to cover the part of the exposed optical fiber housed in the groove. The shape of the lid may be a shape in which a groove for separately accommodating each optical fiber is formed on the surface facing the substrate, but it is accommodated in the groove on the surface facing the substrate. It is desirable to have a shape in which a concave portion for accommodating all the optical fibers that have not been formed is formed. The recess for accommodating the optical fibers at once is easy to form,
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, when the lid is provided with a recess for accommodating the optical fibers all at once, the shape of the recess is formed by combining only planes intersecting at right angles, or by a curved surface. A shape, a shape combining a flat surface and a curved surface, and the like can be given. The depth of the recess is
It is desirable that the height is the same as the height of the portion of the optical fiber which is not accommodated in the groove.

Examples of the material of the lid include the same materials as those of the substrate. The material of the lid and the material of the substrate may be the same,
It may be different. Further, the formation of the recess may be performed by subjecting the plate-shaped body made of these to cutting processing when the lid is made of an inorganic material or a metal material, and when the lid is made of an organic material. After molding the organic material into a plate-like body, it is subjected to exposure and development treatment or laser treatment,
Alternatively, it may be performed by cutting a plate-shaped body made of a completely cured organic material.

The shape of the lid may be a shape that covers the entire surface of the substrate (a shape that integrally covers the grooved region and the coating resin layer holding portion). Further, a lid having a shape that covers only the region where the groove of the substrate is formed on the substrate and a lid that has a shape covering only the coating resin layer holding portion may be separately attached.

When such a lid is formed, an adhesive may be poured into the gap between the lid and the optical fiber and the adhesive may be cured to fix the lid and the optical fiber. desirable. In addition, after the optical fiber is housed in the groove of the substrate, before the optical fiber is fixed to the groove, the lid is formed first, and then the gap between the groove and the optical fiber,
It is desirable to pour the adhesive into the gap between the recess and the optical fiber at the same time. This is because when the lid is placed on the adhesive after the adhesive is applied, air easily enters between the adhesive and the lid.

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 accommodated, and the portion of the optical fiber ribbon which is not accommodated in the substrate is cut and removed. In this case, it is desirable that this cutting removal be performed after the lid is formed.

Also, after storing the optical fiber ribbon with one end exposed, or after storing a part of the exposed optical fiber other than both ends and cutting and removing one end of the optical fiber ribbon. It is desirable to polish the end surface of the optical fiber. Here, when performing the polishing treatment, it is desirable to perform the polishing treatment so that the end faces of the optical fiber, the substrate and the lid are inclined. This is because it is possible to suppress the generation of return light when transmitting an optical signal. In this case, while polishing the end face of the optical fiber,
The side surface of the substrate or the lid may be polished.

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. 6 is a partial perspective view schematically showing an embodiment of the laminated optical fiber ribbon.

As shown in FIG. 6, the laminated optical fiber ribbon 300 has a part of the optical fibers 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. In the laminated optical fiber ribbon 300 shown in FIG. 6, 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. 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 using a method of using a coating resin peeling device, a method of dissolving with an organic solvent, a method of irradiating with a laser beam, and the like, apart from this, 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 by using the same method for removing the coating resin layer as described above. After bending, the first and second optical fiber ribbons may be stacked with an adhesive so that the two optical fibers are alternately arranged at equal intervals.

As a method for accommodating and fixing such a laminated optical fiber ribbon on a 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.

[0103]

The present invention will be described in more detail below.

(Example 1) A. Production of optical fiber ribbon from which a part of the coating resin layer has been removed (1) Eight optical fibers 115 having a diameter of 250 μm are arranged in parallel with a clad interval of 250 μm, and an acrylate-based ultraviolet curable resin is formed around the optical fibers. An optical fiber ribbon (manufactured by Sumitomo Electric Industries, Ltd.) coated with a coating resin layer (primary coating layer 113 and secondary coating layer 114) is prepared, and a portion 5 to 50 mm from one end of the optical fiber ribbon is prepared. The coating resin layers (primary coating layer and secondary coating layer) were peeled off by the following method (see FIG. 7 (a)).

That is, first, after fixing the above-mentioned optical fiber ribbon on the copper clad laminate, 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.

[0106]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

(2) Next, the coating resin layer 114a on the side to be cut and removed in a later step and the exposed optical fiber 115 are immersed in a 1 wt% HF aqueous solution for 60 seconds to expose the surface of the exposed optical fiber. A roughened surface having an average roughness Ra of 20 nm was formed on. The average roughness Ra was measured using a surface roughness measuring device (Veeco, Wyko).

B. Fabrication of the lid portion A substrate made of quartz glass was subjected to a cutting process using a diamond cutter to form a concave portion 161 for accommodating the exposed optical fiber, thereby forming a lid portion 160 (see FIG. 8A). ). The recess has a rectangular cross section.

C. Fabrication of optical fiber array (1) Thickness 0.5-2.0 with polishing treatment on its surface
A silicon substrate 151 having a size of mm was used as a starting material, and a mask layer 152 was formed on the silicon substrate 151 by the following method (see FIG. 4A). That is, first, the surface of the silicon substrate 151 by thermal oxidation furnace to form a SiO ₂ film 152a having a thickness of 0.04 .mu.m, then using a vacuum CVD method on this SiO ₂ film, a thickness of 0. 1 μm Si ₃ N ₄
The SiO ₂ film 152a is formed by forming the film 152b.
And a Si ₃ N ₄ film 152b as a mask layer 15 composed of two layers.
Formed 2.

(2) Next, a thickness of 2 is formed on the mask layer 152.
A resin layer for resist 154 was formed by sticking a resin film for resist of 5 μm (see FIG. 4B).

(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. 4 (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. 4 (d)). 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 peeled and removed using a 10 wt% NaOH aqueous solution (FIG. 4).
(See (e)). 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 120 μm (see FIG. 4 (f)). Then the substrate 15
A coating resin layer holding portion 158 (see FIG. 7A) for holding the optical fiber ribbon together with the coating resin layer in a part of 1
It was formed by performing a cutting process using a diamond cutter. Although only four grooves are formed on the substrate shown in FIG. 7, this figure is a schematic diagram, and in fact, as described above, eight grooves were formed on the substrate.

(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-shaped groove 157 (see FIGS. 7A and 7B), and the lid 160 manufactured in the above B is placed on the substrate 151 via an adhesive (UV-3000 manufactured by Daikin Industries, Ltd.). It was attached (see FIG. 8 (a)). The adhesive was previously applied to the outer edge of the lid. Furthermore, an adhesive (U, manufactured by Daikin Industries, Ltd., U manufactured by Daikin Industries, Ltd.
V-3000) was poured. Further, the adhesive (U) is also applied to the periphery of the coating resin layer placed on the coating resin layer holding portion 158.
V-3000) was applied.

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

(8) Next, the coating resin layer 114a not accommodated 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. 8B).

(Example 2) In the process B of Example 1 (preparation of the lid portion), 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. 9A), and in the step (7) of C of the embodiment 1, the light is emitted in the same manner as in the embodiment 1 except that the lid portion 170 is attached to the substrate. Fiber array 1
02 was produced (see FIG. 9 (b)).

(Example 3) A. Fabrication of laminated optical fiber ribbon from which some coating resin layers have been removed (1) An optical fiber with a diameter of 250 μm has a clad spacing of 2
Optical fiber ribbons (manufactured by Sumitomo Electric Industries, Ltd.) that are arranged in parallel with each other at 50 μm and have a coating resin layer (primary coating layer and secondary coating layer) made of an acrylate ultraviolet curing adhesive around the optical fibers. 2) 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 layer (primary coating layer and secondary coating layer) up to mm was removed under the same conditions as in step A of Example 1 to expose the optical fiber. Next, the exposed optical fiber is immersed in a 1% by weight HF aqueous solution for 60 seconds, so that the surface of the exposed optical fiber has an average roughness R.
a: A roughened surface having a thickness of 20 nm was formed to obtain a first optical fiber ribbon.

(Ii) 5 to 50 m from one end of the optical fiber
The coating resin layer (primary coating layer and secondary coating layer) at the portion m was removed under the same conditions as in step A of Example 1 to expose the optical fiber. Next, the coating resin layer on the side to be cut and removed in a later step and the exposed optical fiber were dipped in a 1 wt% HF aqueous solution for 60 seconds to give an average roughness Ra: 20n on the surface of the exposed optical fiber.
A roughened surface of m was formed to obtain a second optical fiber ribbon.

(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 addition, in this step, before the first optical fiber ribbon 330 is stacked on the second optical fiber ribbon 340, an adhesive (a part of the upper surface of the secondary coating resin of the second optical fiber ribbon 340 is previously formed ( (Not shown) is applied in advance, and the second optical fiber ribbon 34 is applied through the adhesive.
The first optical fiber ribbons 330 were stacked on top of each other, and then the adhesive was cured to fix the two.

B. Fabrication of lid The lid was formed in the same manner as in Example 1B, except that the size of the recess was set to accommodate the exposed optical fiber.

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. Furthermore, an adhesive (U, manufactured by Daikin Industries Ltd., U manufactured by Daikin Industries Ltd.)
V-3000) was poured. In addition, the adhesive (UV-
3000) was applied.

Next, ultraviolet rays of 10 J / cm ² were radiated from above 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 coated 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.

(Embodiment 4) When forming a lid, a recess for accommodating exposed optical fibers having different depths, and
A lid was formed in the same manner as in Example 2 except that a lid having a recess for accommodating the optical fiber ribbon together with the coating resin layer was formed, and using this lid, the C of Example 3 ( An optical fiber array was manufactured in the same manner as in Example 3 except that the step 2) was performed.

(Comparative Example 1) The procedure of Example 1 was repeated, except that the step (2) of A of Example 1, that is, the step of forming a roughened surface on the exposed surface of the optical fiber was not performed. An optical fiber array was manufactured. The average roughness Ra of the exposed surface of the optical fiber was less than 1.0 nm.

Comparative Example 2 An optical fiber array was manufactured in the same manner as in Example 2 except that the step of forming a roughened surface on the exposed surface of the optical fiber was not performed as in Comparative Example 1.

The optical fiber arrays obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were heated at 130 ° C. for 3 minutes, and
One cycle is a cycle of holding at -65 ° C for 3 minutes,
A reliability test was performed in which this cycle was repeated 1000 times, and then the optical fiber array was cut in the axial direction of the optical fiber array so as to pass through the optical fiber, and the cross section was observed.

As a result, in the optical fiber arrays of Examples 1 to 4, no peeling was observed between the adhesive and the substrate, the optical fiber, or the lid, and cracks were also generated in the adhesive. There wasn't. On the other hand, in the optical fiber arrays of Comparative Examples 1 and 2, there was a portion where peeling occurred between the adhesive and the optical fiber. Also, cracks were generated in a part of the adhesive.

Further, Examples 1 to 4 before carrying out the reliability test
After disassembling the optical fiber array and observing how the adhesive was filled, the gap between the groove and the optical fiber and the gap between the lid and the optical fiber were completely filled with the adhesive.
No void was found in the adhesive. On the other hand, when the optical fiber arrays of Comparative Examples 1 and 2 before the reliability test were disassembled and the filling state of the adhesive was observed, a portion not filled with the adhesive or a void in the adhesive was found. There was a part that was occurring.

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.
I was satisfied with the quality required for the product.

[0136]

As described above, since the optical fiber array of the present invention has the above-mentioned structure, the optical fiber and the adhesive have excellent adhesiveness, and the optical fiber has a groove formed surely on the substrate. It will be stored and fixed in. Further, in the optical fiber array of the present invention, the wetting of the uncured adhesive on the surface of the optical fiber is improved, and the adhesive is surely filled in the gap between the groove and the optical fiber. Is securely fixed to.

[Brief description of drawings]

FIG. 1A is a partial perspective view schematically showing an example of an optical fiber array of the present invention, and FIG. 1B is a part A of FIG.
FIG.

FIG. 2A is a partial perspective view schematically showing an example of the 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. 3 is a partial perspective view schematically showing an example of an optical fiber array of the present invention using a laminated optical fiber ribbon.

4A to 4F are cross-sectional views showing an example of a method for forming a groove in a substrate.

5A is a front view schematically showing an example of such a processing method of the present invention, and FIG. 5B is a side view thereof.

FIG. 6 is a partial perspective view schematically showing an embodiment of a laminated optical fiber ribbon.

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 and 9B are perspective views schematically showing a part of the manufacturing process of the optical fiber array of the present invention.

[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

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Claims (3)

[Claims] 1. An optical fiber array in which a plurality of grooves are formed in a part of a substrate, and the optical fibers are housed in the grooves via an adhesive, and the surface of the optical fiber is roughened. An optical fiber array characterized in that a surface is formed. 2. The average roughness Ra of the roughened surface is 1 to 10.
The optical fiber array according to claim 1, which is 0 nm. 3. The optical fiber array according to claim 1, wherein the roughened surface is formed by using a roughening liquid containing fluoride.