WO2024116542A1

WO2024116542A1 - Optical fiber holding member, optical connector, method for manufacturing optical fiber holding member, and method for manufacturing optical connector

Info

Publication number: WO2024116542A1
Application number: PCT/JP2023/033238
Authority: WO
Inventors: 卓朗渡邊; 大佐々木; 知巳佐野
Original assignee: 住友電気工業株式会社
Priority date: 2022-11-28
Filing date: 2023-09-12
Publication date: 2024-06-06

Abstract

An optical fiber holding member (4) comprises a holding unit (4f) configured to hold an optical fiber (2). The optical fiber holding member (4) is configured to include a base resin (40) and a plurality of types of fillers (41, 42). The light transmittance of the optical fiber holding member (4) in the wavelength region of 300-400 nm is 50% or greater, and the linear expansion coefficient of the optical fiber holding member (4) is 5×10^-5/°C or less. In this optical fiber holding member (4), the particle size distributions of the fillers (41, 42) have peaks in each of a plurality of particle size ranges.

Description

Optical fiber holding member, optical connector, manufacturing method of optical fiber holding member, and manufacturing method of optical connector

The present disclosure relates to an optical fiber holding member, an optical connector, a manufacturing method of an optical fiber holding member, and a manufacturing method of an optical connector.
This application claims priority based on Japanese Application No. 2022-189118 filed on November 28, 2022, and incorporates by reference all of the contents of said Japanese application.

Patent Document 1 discloses an optical fiber array that includes optical fibers and a support member that supports the optical fibers. In this optical fiber array, the support member is composed of a base resin and a filler that is mixed into the base resin at a predetermined mass ratio. This gives the support member, which is ultraviolet-transmitting, a low linear expansion coefficient. Patent Document 2 discloses a multi-core MT cord with optical fibers attached.

International Publication No. 2017/170689 Japanese Patent Application Laid-Open No. 9-159868

One aspect of the present disclosure relates to an optical fiber holding member including a holding part configured to hold an optical fiber. The optical fiber holding member is configured to include a base resin and multiple types of fillers. The optical fiber holding member has a light transmittance of 50% or more in a wavelength range of 300 nm or more and 400 nm or less, and a linear expansion coefficient of 5×10 ^-5 /° C. or less. In this optical fiber holding member, the particle size distribution of the filler has peaks in each of multiple particle size ranges.

FIG. 1 is a perspective view showing an optical connector according to an embodiment. FIG. 2 is a top view showing an optical connector according to an embodiment. FIG. 3 is a perspective view showing an optical fiber holding member provided in the optical connector. FIG. 4 is a diagram showing a schematic view of a base resin and a filler in an optical fiber holding member.

[Problem to be solved by this disclosure]
In Patent Document 1, a base resin mixed with a filler is used to produce an optical fiber array (holding member) having ultraviolet light transmittance. In this way, Patent Document 1 produces an optical fiber array (holding member) having a low linear expansion coefficient. However, in this optical fiber array, one type of filler (average particle size 20 μm) is mixed into the base resin to produce the holding member (see the examples in Patent Document 1). For this reason, voids are likely to occur between the fillers, making it difficult to increase the filler content. If the filler content is increased in order to reduce the linear expansion coefficient in the configuration of this holding member, the fluidity of the resin material used for molding will decrease. As a result, the manufacturing efficiency of the holding member will decrease.

[Effects of the present disclosure]
According to the present disclosure, an optical fiber holding member having ultraviolet light transmittance and a low linear expansion coefficient can be efficiently manufactured.

[Description of the embodiments of the present disclosure]
First, the contents of the embodiments of the present disclosure will be listed and described.
[1] An optical fiber holding member according to an embodiment of the present disclosure includes a holding portion configured to hold an optical fiber. The optical fiber holding member is configured to include a base resin and multiple types of fillers. The optical fiber holding member has a light transmittance of 50% or more in a wavelength range of 300 nm or more and 400 nm or less, and a linear expansion coefficient of 5×10 ^-5 /° C. or less. In this optical fiber holding member, the particle size distribution of the filler has peaks in each of multiple particle size ranges.

In this optical fiber holding member, the light transmittance in the wavelength range of 300 nm to 400 nm is 50% or more, and the linear expansion coefficient is 5×10 ⁻⁵ /° C. or less, so that the optical fiber holding member has ultraviolet transmittance and a low linear expansion coefficient. Furthermore, in this optical fiber holding member, fillers are contained in a predetermined mass ratio, and the particle size distribution of these fillers has peaks in each of a plurality of particle size ranges. In this case, at least two types of fillers, that is, fillers with large particle sizes and fillers with small particle sizes, are contained in the optical fiber holding member, so that the small fillers enter the gaps between the large fillers. As a result, the filling property of the fillers is improved. Therefore, even if the content of the filler is increased, the moldability can be improved without decreasing the fluidity of the molten resin material containing the filler. Therefore, according to this optical fiber holding member, an optical fiber holding member having ultraviolet transmittance and a low linear expansion coefficient can be efficiently manufactured. Furthermore, according to this optical fiber holding member, since it can be manufactured by a molding method with high fluidity, it is easy to make it into a high-precision optical fiber holding member.

[2] In the optical fiber holding member of [1] above, the ratio of the filler in the resin material containing the base resin and the filler is 50% by mass or more, and the multiple particle size ranges may include a first particle size range of 10 μm or less and a second particle size range of 18 μm or more and 32 μm or less. In this case, the filler corresponding to the peak of the first particle size range enters the gap between the fillers corresponding to the peak of the second particle size range, improving the filling of the filler. Therefore, the volume of the filler, which is 50% by mass or more, is reduced, and the filler is efficiently blended. In addition, since the particle size of the filler is small, the fluidity of the filler is further improved. Therefore, according to this optical fiber holding member, it is possible to obtain an optical fiber holding member that has ultraviolet transmittance and a low linear expansion coefficient while having high dimensional accuracy.

[3] In the optical fiber holding member of [2] above, the proportion of the filler in the resin material may be greater than 70 mass %. In this case, the optical fiber holding member can have a further reduced linear expansion coefficient.

[4] In the optical fiber holding member of [2] or [3] above, the first particle size range may be 6 μm or less, and the second particle size range may be 22 μm or more and 28 μm or less.

[5] In any of the optical fiber holding members described above in [1] to [4], the base resin may be at least one amorphous thermoplastic resin selected from the group consisting of cycloolefin polymers, cycloolefin copolymers, and polycarbonates. In this case, since the base resin has heat resistance in addition to high transparency, the optical fiber holding member can also have heat resistance.

[6] In any of the optical fiber holding members [1] to [5] above, the filler contains spherical silica particles, and a surface modifier may be added to the surface of the silica particles. In this case, the surface modifier can easily reduce the difference in refractive index between the base resin and the filler. Therefore, ultraviolet light transmittance can be easily imparted to the optical fiber holding member. In addition, since the filler contains spherical silica particles, the isotropy of the linear expansion coefficient of the optical fiber holding member can be increased.

[7] In any of the optical fiber holding members [1] to [6] above, the particle size distribution of the filler may have a peak in each of three or more particle size ranges.

[8] Any of the optical fiber holding members [1] to [7] above may be provided with an opening through which the optical fiber is inserted and a window that connects the space connected to the opening with the outside, and the holding portion may be provided within the space. In this case, adhesive can be easily introduced into the optical fiber holding member through the window.

An optical connector according to one embodiment of the present disclosure includes an optical fiber holding member according to any one of [1] to [8] above, and an optical fiber fixed to the optical fiber holding member with an ultraviolet-curing adhesive. According to this optical connector, since the optical fiber holding member is ultraviolet-transparent, the optical fiber can be fixed to the optical fiber holding member with an ultraviolet-curing adhesive. As a result, the manufacturing time of the optical connector can be shortened.

A method for manufacturing an optical fiber holding member according to one embodiment of the present disclosure includes the steps of preparing a mold having a cavity corresponding to the optical fiber holding member, preparing a base resin that is an amorphous thermoplastic resin and multiple types of fillers, adding a surface modifier to the surface of the filler particles, generating a resin composition by mixing the base resin and the filler so that the filler is contained at 50% by mass or more, and injecting the resin composition into a mold to mold an optical fiber holding member. In this manufacturing method, since the particle size distribution of the filler has peaks in each of multiple particle size ranges, the filler can be easily blended so that the filler is contained at 50% by mass or more. Therefore, according to this manufacturing method for an optical fiber holding member, an optical fiber holding member having ultraviolet light transmittance and a low linear expansion coefficient can be efficiently manufactured.

The method for manufacturing an optical connector according to one embodiment of the present disclosure includes the steps of preparing an optical fiber holding member according to any one of [1] to [8] above, and arranging an optical fiber in the holding portion, applying an ultraviolet-curing adhesive to the optical fiber, and irradiating the optical fiber holding member with ultraviolet light from the outside to cure the ultraviolet-curing adhesive. In this method for manufacturing an optical connector, since the optical fiber holding member is ultraviolet-transparent, an ultraviolet-curing adhesive can be used. This allows the optical fiber to be fixed to the optical fiber holding member in a short time. Therefore, according to this method for manufacturing an optical connector, the manufacturing time of an optical connector equipped with an optical fiber holding member that is ultraviolet-transparent and has a low linear expansion coefficient can be shortened.

[Details of the embodiment of the present disclosure]
Specific examples of the optical fiber holding member and optical connector according to the present disclosure will be described below with reference to the drawings. The present invention is not limited to these examples, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions will be omitted.

FIGS. 1 and 2 are diagrams showing an example of an optical connector according to this embodiment. FIG. 3 is a perspective view showing an example of an optical fiber holding member. As shown in FIGS. 1 and 2, the optical connector 1 comprises a cable 3 including a plurality of optical fibers 2, an optical fiber holding member 4 (hereinafter simply referred to as "holding member 4") that holds the plurality of optical fibers 2, and a resin boot 5 attached to the holding member 4. When the optical connector 1 is connected to another optical module, the optical fiber 2 and the other optical module are optically coupled.

The cable 3 is a member that protects the optical fibers 2 by covering them with a coating resin or the like. As shown in FIG. 2, the cable 3 has multiple optical fibers 2 arranged in a horizontal direction. The number of optical fibers 2 included in the cable 3 is not particularly limited, but is, for example, 12. The front ends 2a of the optical fibers 2 are exposed from the front end 3a of the cable 3. The exposed front ends 2a are arranged in the holding portion 4f of the holding member 4 (see also FIG. 3). As a result, the front ends 2a are held by the holding portion 4f.

The holding member 4 is a rectangular member that holds the optical fiber 2 and positions the optical fiber 2. As described later, the holding member 4 is formed from a resin material in which multiple types of fillers are mixed with a base resin. As shown in Figures 1 to 3, the holding member 4 has a front end face 4a, a rear end face 4b, an upper face 4c, a pair of guide holes 4d, an opening 4e, a holding portion 4f, and a window 4g. The front end face 4a faces the other optical module when the optical connector 1 is connected to the other optical module. The rear end face 4b faces the front end face 4a. The pair of guide holes 4d penetrate the inside of the holding member 4 from the front end face 4a to the rear end face 4b. The pair of guide pins of the other optical module are inserted into the pair of guide holes 4d, thereby connecting the optical connector 1 to the other optical module. The opening 4e is formed from the rear end face 4b to the vicinity of the center of the holding member 4. The boot 5 holding the cable 3 is inserted into the opening 4e. The optical fiber 2 is held in the holding part 4f, which is provided in the space connected to the opening 4e.

The holding portion 4f is formed from the opening 4e to the front end face 4a as shown in FIG. 3, and is a portion that holds multiple optical fibers. The holding portion 4f may be a cylindrical hole, or may be a combination of a cylindrical hole and a groove formed continuously with the hole. In the optical connector 1 according to this embodiment, the holding portion 4f is composed of a cylindrical hole and a groove formed continuously with the hole. The front end 2a of the optical fiber 2 exposed from the cable 3 is placed and held in the holding portion 4f. The front end face 2b of the optical fiber 2 is exposed from the front end face 4a as shown in FIG. 2. The front end face 2b and the front end face 4a are polished so that no gap is generated between the optical fiber 2 and another optical module when the optical fiber 2 is connected to the other optical module.

As shown in FIG. 3, the window 4g is formed from the top surface 4c to the opening 4e, and is a hole for introducing adhesive (not shown) into the inside of the holding member 4. After inserting the boot 5 into the opening 4e and placing the optical fiber 2 in the holding portion 4f, adhesive is introduced from the window 4g. This causes the optical fiber 2 to be fixed to the holding portion 4f of the holding member 4. The adhesive is, for example, an ultraviolet-curing adhesive.

Here, the material composition of the holding member 4 will be described with reference to FIG. 4. FIG. 4 is a diagram showing a base resin and a filler in an optical fiber holding member. The holding member 4 is formed from a resin material in which multiple types of

fillers

41 and 42 are mixed into a base resin 40. The base resin 40 is an amorphous thermoplastic resin. The base resin 40 is made of a material that can transmit ultraviolet rays having a wavelength range of 300 nm to 400 nm. The light transmittance of the base resin 40 in the wavelength range of 300 nm to 400 nm is at least 50%. Such a base resin 40 is, for example, cycloolefin polymer (COP), cycloolefin copolymer (COC), or polycarbonate (PC). The light transmittance of the holding member 4 is measured by a transmittance measurement in accordance with, for example, ISO13468.

The

fillers

41 and 42 are, for example, inorganic fillers, and as an example, silica (SiO ₂ ) fillers. The mass ratio of the

fillers

41 and 42 in the holding member 4 is 50 mass% or more. The mass ratio of the

fillers

41 and 42 may be 60 mass% or more, 65 mass% or more, more than 70 mass%, or 80 mass% or more. By blending the

fillers

41 and 42 at a high ratio in this way, the linear expansion coefficient of the holding member 4 can be reduced to 5×10 ⁻⁵ /°C or less, and depending on the filling rate, it can be reduced to 3×10 ⁻⁵ /°C or less. The linear expansion coefficient of the holding member 4 is measured, for example, by thermomechanical analysis (TMA) in accordance with ISO11359. Here, the mass ratio is the ratio of the mass of the

fillers

41 and 42 to the total mass of the holding member 4 (the total mass of the resin material including the base resin 40 and the fillers 41 and 42). The mass ratio of the

fillers

41, 42 in the holding member 4 is measured by, for example, thermogravimetric analysis (TGA) in accordance with ISO 7111. Note that the

fillers

41, 42 may be organic fillers or a mixture of both inorganic fillers and organic fillers as long as they can reduce the linear expansion coefficient.

The base resin 40 and the

fillers

41, 42 are configured so that the difference in refractive index between the base resin 40 and the

fillers

41, 42 is small. The refractive index may be adjusted by a known method, for example, by adding a surface modifier for adjusting the refractive index to the

fillers

41, 42. An example of the surface modifier is a silane coupling agent. In this way, since the difference in refractive index between the base resin 40 and the

fillers

41, 42 is small, even when the

fillers

41, 42 are mixed with the base resin 40, the light transmittance of the holding member 4 in the wavelength range of 300 nm to 400 nm can be 50% or more. In other words, the holding member 4 can have ultraviolet light transparency. Since the holding member 4 has ultraviolet light transparency, when an ultraviolet-curing adhesive is introduced from the window 4g, the adhesive is cured by irradiating ultraviolet light from the outside of the holding member 4. This makes it possible to easily fix the optical fiber 2 to the holding member 4. As a result, the manufacturing time of the optical connector 1 can be shortened.

The

fillers

41, 42 are spherical particles. Here, spherical includes true spherical and nearly spherical, and may have chips, holes, or recesses. As a result, the

fillers

41, 42 are isotropically blended into the retaining member 4, which can increase the isotropy of the linear expansion coefficient of the retaining member 4. In addition, since the

fillers

41, 42 that fall off when the front end face 4a is polished are spherical, damage to the front end face 2b can be suppressed.

The particle size distribution of filler 41 is generally normal and has one peak. The particle size distribution of filler 42 is generally normal and has one peak. The particle size distribution of filler 42 has a peak in the first particle size range. The particle size distribution of filler 41 has a peak in the second particle size range. Here, the first particle size range (filler 42) is 10 μm or less, and the second particle size range (filler 41) is 18 μm or more and 32 μm or less. As long as the upper limit of the first particle size range is smaller than the lower limit of the second particle size range, the ranges of the first particle size range and the second particle size range are not particularly limited. The first particle size range may be less than 10 μm, 8 μm or less, 6 μm or less, or 4 μm or less, and the second particle size range may be 20 μm or more and 30 μm or less, or 22 μm or more and 28 μm or less. In this way, the particle size distribution of the filler 41 has a peak in the second particle size range, and the particle size distribution of the filler 42 has a peak in the first particle size range, so that the filler 42 having a particle size corresponding to the peak of the first particle size range enters the gap between the fillers 41 having a particle size corresponding to the peak of the second particle size range. As a result, the filling property of the filler can be improved. The particle size distribution of the filler may have a peak in each of three or more particle size ranges. The particle size distribution of the filler is measured, for example, using a laser diffraction method or an optical microscope.

Next, a method for manufacturing the retaining member 4 will be described. In the method for manufacturing the retaining member 4, first, a mold having a cavity corresponding to the external shape of the retaining member 4 and a nest corresponding to the internal structure (e.g., retaining portion 4f) are prepared. Then, the nest for forming the retaining portion 4f, etc. is placed at a predetermined position within the cavity.

Next, a base resin 40, which is an amorphous thermoplastic resin, and

fillers

41 and 42 are prepared. Here, the base resin 40 is, for example, cycloolefin polymer (COP), cycloolefin copolymer (COC), or polycarbonate (PC).

The

fillers

41 and 42 are, for example, silica fillers having different particle size distributions. The filler 42 in the first particle size range has a peak in a particle size range of, for example, 10 μm or less. The filler 41 in the second particle size range has a peak in a particle size range of, for example, 18 μm or more and 32 μm or less. When adjusting the particle size of the filler, the ranges of the first particle size range and the second particle size range are not particularly limited as long as the upper limit of the first particle size range is smaller than the lower limit of the second particle size range. The peak of the first particle size range may be less than 10 μm, 8 μm or less, 6 μm or less, or 4 μm or less. The peak of the second particle size range may be 20 μm or more and 30 μm or less, or 22 μm or more and 28 μm or less. The

fillers

41 and 42 with different particle size distributions prepared here may be different types of fillers having peaks in three or more particle size ranges. The particle size of the filler can be adjusted, for example, by classifying the filler, but other methods may also be used.

Next, once preparation of the base resin 40 and the

fillers

41, 42 is complete, a surface modifier is added to the surfaces of the particles of the

fillers

41, 42 so that the difference in refractive index between the base resin 40 and the

fillers

41, 42 is small. Here, the surface modifier is, for example, a silane coupling agent. Furthermore, since the difference in refractive index between the base resin 40 and the

fillers

41, 42 is thus small, the molded optical fiber holding member 4 can have a light transmittance of 50% or more in the wavelength range of 300 nm to 400 nm. This allows the use of ultraviolet-curing adhesives when manufacturing optical connectors.

Next, after the addition of the surface modifier to the

fillers

41 and 42 and the adjustment of the particle size of the filler are completed, the base resin and the filler are mixed to produce a resin composition so that the filler is contained in 50 mass% or more. Since the filler is contained in 50 mass% or more, the linear expansion coefficient of the molded optical fiber holding member 4 can be set to 5×10 ⁻⁵ /° C. or less. In addition, since the particle size distribution of the filler has peaks in a first particle size range of 10 μm or less and a second particle size range of 18 μm or more and 32 μm or less, the filler 42 having a particle size corresponding to the peak of the first particle size range enters into the gap between the fillers 41 having a particle size corresponding to the peak of the second particle size range. As a result, the filling property of the filler in the resin composition is improved.

Next, when the production of the resin composition is completed, the resin composition is melted and the molten resin composition is injected into the cavity of the mold. Here, the resin composition is injected with the nest placed in the cavity. After the resin composition is injected, it is cured to form the holding member 4.

Next, a method for further manufacturing an optical connector using such a holding member 4 will be described. In the method for manufacturing an optical connector, once the holding member 4 is prepared, a boot 5 is attached to the cable 3 holding the optical fiber 2. Then, this boot 5 is inserted into the opening 4e of the holding member 4. After that, the front end 2a of the optical fiber 2 exposed from the cable 3 is placed in the holding portion 4f of the holding member 4.

Next, when the optical fiber 2 is placed in the holding portion 4f, an ultraviolet-curing adhesive is introduced through the window 4g of the holding member 4, and the ultraviolet-curing adhesive is applied to the optical fiber 2 and the holding portion 4f. After that, ultraviolet light is irradiated from the outside of the holding member 4 to harden the ultraviolet-curing adhesive. This fixes the optical fiber 2 to the holding member 4. In this way, by fixing the optical fiber 2 to the holding member 4 using an ultraviolet-curing adhesive, the manufacturing time of the optical connector 1 can be shortened. The above-mentioned optical connector 1 can be obtained by the above manufacturing method.

As described above, in the holding member 4 according to this embodiment, the light transmittance in the wavelength region of 300 nm to 400 nm is 50% or more, and the linear expansion coefficient is 5×10 ⁻⁵ /° C. or less, so that the holding member 4 has ultraviolet transmittance and a low linear expansion coefficient. Furthermore, in the holding member 4, the

fillers

41 and 42 are contained at a predetermined mass ratio, and the particle size distribution of the

fillers

41 and 42 has peaks in each of a plurality of particle size ranges. In this way, at least two types of fillers, the filler 41 having a large particle size and the filler 42 having a small particle size, are contained in the holding member 4, so that the small filler 42 enters the gap between the large fillers 41. As a result, the filling property of the filler is improved. Therefore, even if the content of the filler is increased, the moldability can be improved without decreasing the fluidity of the molten resin material containing the filler. Therefore, according to the holding member 4, the holding member 4 having ultraviolet transmittance and a low linear expansion coefficient can be efficiently manufactured. In addition, since the holding member 4 can be manufactured by a molding method with high fluidity, it is also possible to obtain a holding member 4 with high precision.

In the retaining member 4 according to this embodiment, the ratio of the

fillers

41 and 42 in the resin material containing the base resin 40 and the

fillers

41 and 42 is 50% by mass or more, and the multiple particle size ranges include a first particle size range of 10 μm or less and a second particle size range of 18 μm or more and 32 μm or less. As a result, the filler 42 corresponding to the peak of the first particle size range enters the gap between the fillers 41 corresponding to the peak of the second particle size range, thereby improving the filling of the filler. Therefore, the volume of the

fillers

41 and 42, which are 50% by mass or more, is reduced, and the filler is efficiently blended. In addition, since the particle size of the

fillers

41 and 42 is small, the fluidity of the filler is increased. Therefore, according to the retaining member 4, it is possible to obtain a retaining member with high dimensional accuracy while having ultraviolet transmittance and a low linear expansion coefficient. In the retaining member 4, the ratio of the

fillers

41 and 42 in the resin material may be greater than 70% by mass. As a result, it is possible to obtain a retaining member 4 with a further reduced linear expansion coefficient.

In the retaining member 4 according to this embodiment, the base resin 40 is at least one amorphous thermoplastic resin selected from the group consisting of cycloolefin polymer, cycloolefin copolymer, and polycarbonate. This gives the base resin 40 high transparency and heat resistance, which further enhances the heat resistance of the retaining member 4.

In the retaining member 4 according to this embodiment, the

fillers

41 and 42 contain spherical silica particles, and a surface modifier is added to the surface of the silica particles. Even if the

fillers

41 and 42 are blended into the retaining member 4, the difference in refractive index between the base resin 40 and the

fillers

41 and 42 can be easily reduced by the surface modifier. Therefore, UV transparency can be easily imparted to the retaining member 4. Because the

fillers

41 and 42 contain spherical silica particles, the isotropy of the linear expansion coefficient of the retaining member 4 can be increased.

The optical connector 1 according to this embodiment includes the holding member 4 described above, and the optical fiber 2 fixed to the holding member 4 with an ultraviolet-curing adhesive. As described above, in this optical connector 1, the holding member 4 is ultraviolet-transparent, so the optical fiber 2 can be easily fixed to the holding member 4 with an ultraviolet-curing adhesive. As a result, the manufacturing time of the optical connector 1 can be shortened. In addition, in the optical connector 1, the filler is mixed into the holding member 4 in the ratio described above, so that the optical connector 1 can have a low linear expansion coefficient.

The manufacturing method of the retaining member 4 according to this embodiment includes the steps of preparing a mold having a cavity corresponding to the retaining member 4, preparing a base resin 40, which is an amorphous thermoplastic resin, and

fillers

41 and 42, adding a surface modifier to the surfaces of the particles of the

fillers

41 and 42, producing a resin composition by mixing the base resin 40 and the

fillers

41 and 42 so that the

fillers

41 and 42 are contained at 50% by mass or more, and injecting the resin composition into a mold to mold the retaining member 4. In this manufacturing method, the particle size distribution of the

fillers

41 and 42 has peaks in each of a plurality of particle size ranges. Therefore, the fillers can be easily mixed so that the

fillers

41 and 42 are contained at 50% by mass or more. Therefore, according to this manufacturing method of the retaining member 4, a retaining member having ultraviolet transmittance and a low linear expansion coefficient can be efficiently manufactured.

The manufacturing method of the optical connector 1 according to this embodiment includes the steps of preparing the optical fiber holding member 4, placing the optical fiber 2 in the holding portion 4f, applying an ultraviolet-curing adhesive to the optical fiber 2, and irradiating the holding member 4 with ultraviolet light from the outside to cure the ultraviolet-curing adhesive. In this way, since the holding member 4 is ultraviolet-transparent, an ultraviolet-curing adhesive can be used. As a result, the optical fiber 2 can be fixed to the holding member 4 in a short time. Therefore, according to this manufacturing method of the optical connector 1, the manufacturing time of the optical connector 1 equipped with the holding member 4 having a low linear expansion coefficient can be shortened.

The above describes in detail the embodiments of the present disclosure, but the present invention is not limited to the above embodiments and can be applied to various embodiments. For example, in the above embodiment, an example was described in which the holding member 4 is a ferrule, but the embodiments of the present disclosure may also be applied to the configuration of an optical fiber array that connects optical fibers and silicon photonics on a substrate.

1...optical connector 2...optical fiber 2a...front end portion 2b...front end surface 3...cable 3a...front end 4...optical fiber holding member (holding member)
4a...front end surface 4b...rear end surface 4c...upper surface 4d...guide hole 4e...opening 4f...holding portion 4g...window 5...boot 40...

base resin

41, 42...filler

Claims

An optical fiber holding member having a holding portion configured to hold an optical fiber,
The optical fiber holding member is configured to include a base resin and a plurality of types of fillers,
the optical fiber holding member has a light transmittance of 50% or more in a wavelength region of 300 nm or more and 400 nm or less, and the optical fiber holding member has a linear expansion coefficient of 5×10 −5 /° C. or less;
The particle size distribution of the filler has peaks in each of a plurality of particle size ranges.
Optical fiber holding member.
The ratio of the filler in a resin material containing the base resin and the filler is 50 mass% or more,
The plurality of particle size ranges include a first particle size range of 10 μm or less and a second particle size range of 18 μm or more and 32 μm or less.
2. The optical fiber holding member according to claim 1.
The proportion of the filler in the resin material is greater than 70 mass%.
3. The optical fiber holding member according to claim 2.
the first particle size range is 6 μm or less;
The second particle size range is 22 μm or more and 28 μm or less.
3. The optical fiber holding member according to claim 2.
The base resin is at least one amorphous thermoplastic resin selected from the group consisting of cycloolefin polymers, cycloolefin copolymers, and polycarbonates.
2. The optical fiber holding member according to claim 1.
The filler includes spherical silica particles,
A surface modifier is added to the surface of the silica particles.
2. The optical fiber holding member according to claim 1.
The particle size distribution of the filler has peaks in each of three or more particle size ranges.
2. The optical fiber holding member according to claim 1.
an opening into which the optical fiber is inserted, and a window communicating a space connected to the opening with the outside,
The holding portion is provided in the space.
2. The optical fiber holding member according to claim 1.
An optical fiber holding member according to any one of claims 1 to 8,
an optical fiber fixed to the optical fiber holding member with an ultraviolet curing adhesive;
An optical connector comprising:
preparing a mold having a cavity corresponding to the optical fiber holding member;
A step of preparing a base resin which is an amorphous thermoplastic resin and a plurality of types of fillers;
adding a surface modifier to the surface of the filler particles;
A step of producing a resin composition by mixing the base resin and the filler so that the filler is contained in an amount of 50 mass% or more;
a step of injecting the resin composition into the mold to mold the optical fiber holding member;
Equipped with
The particle size distribution of the filler has peaks in each of a plurality of particle size ranges.
A method for manufacturing an optical fiber holding member.
A step of preparing an optical fiber holding member according to any one of claims 1 to 8;
a step of placing the optical fiber in the holding part, applying an ultraviolet-curing adhesive to the optical fiber, and curing the ultraviolet-curing adhesive by irradiating ultraviolet light from the outside of the optical fiber holding member;
A method for manufacturing an optical connector comprising: