JP2000304937A - Production of optical fiber array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for the production of an optical fiber array by which the generation of voids in an adhesive layer can be prevented or the peeling of the adhesive can be decreased. SOLUTION: In this method, while at least one end of an optical fiber 3 is held between an optical fiber fixing member 1 and a pressing member 2, these members are fixed with an adhesive 4 to produce an optical fiber array 10. In the photosetting adhesive layer 4 spreading between the optical fiber fixing member 1 and the pressing member 2, light such as UV rays 5 is made to irradiate in the direction along the side face of the adhesive layer 4 or in the direction along the side face of the adhesive layer 4 and at -45 deg. to 45 deg. elevation angle or depression angle from the plane including the adhesive layer 4 so as to harden the adhesive layer 4 to obtain the optical fiber array 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an optical fiber array and the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 6 and FIG. 7, at least one end of an optical fiber 3 is bonded between an optical fiber fixing member 1 and a holding member 2, and these members are bonded. The optical fiber array 10 is manufactured by fixing with the agent 4. The pressing member 2 is not essential, and there is an optical fiber array in which the pressing member 2 is not provided. In the optical fiber array assembly, use ultraviolet (UV) curable adhesive,
Through the optical fiber fixing member 1 and the pressing member 2 that transmit ultraviolet light, ultraviolet light 5 is irradiated from a direction perpendicular to the plane including the adhesive layer 4 by a UV lamp or the like.

[0003]

However, according to the above-mentioned conventional method, voids are generated in the adhesive layer due to polymerization shrinkage of the adhesive, or the adhesive layer is peeled off in a severe environment or for a long time. The position of the optical fiber end is shifted,
In some cases, the loss of optical transmission increases or the optical fiber comes off. For this reason, when an environment test of the optical fiber array is performed and a product that passes is shipped, some products are rejected due to peeling of the adhesive layer, and it has been difficult to improve productivity (yield).

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a method of manufacturing an optical fiber array capable of preventing generation of voids in an adhesive layer and reducing peeling of the adhesive.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found the following. First, in the conventional photocuring of an adhesive, light irradiation is performed from a direction perpendicular to a plane including the adhesive layer, as described above. Therefore, as shown in FIGS. 6 and 7,
Polymerization shrinkage occurs in a direction perpendicular to the plane including the adhesive layer (thickness direction of the adhesive layer), and internal stress in the same direction is generated inside the adhesive layer. First, it was found that peeling between the layers and between the optical fiber fixing member and the adhesive layer easily occurred. It has been found that due to the progress of the peeling in the environmental test, the alignment accuracy of the fiber is deteriorated, and the life of the environmental test such as a high-temperature / high-humidity test and a temperature cycle test is shortened. Conventionally, light was irradiated from the direction perpendicular to the plane containing the adhesive layer, so that polymerization proceeded uniformly over the entire adhesive layer, and voids due to polymerization shrinkage occurred near the fibers arranged and fixed in the grooves. Secondly, it was found that susceptibility was likely to occur.
As a result of further research and development, by irradiating light from the side direction of the adhesive layer (including the direction having a depression angle and elevation angle of -45 to 45 ° with respect to the plane including the adhesive layer), It has been found that polymerization shrinkage occurring in a direction perpendicular to the adhesive layer can be suppressed and reduced, and internal stress in the same direction can be suppressed and reduced. Then, it was found that the occurrence of peeling was suppressed and reduced by the reduction of the stress, and the life of the environmental test could be extended. Further, by irradiating light from the side surface direction of the adhesive layer (including the direction in which the fiber is extended in the length direction), the light is irradiated from the side surface of the adhesive layer toward the depth direction (from the irradiation direction to the inside). T) It was found that the light intensity gradually decreased, and a polymerization rate (curing rate) gradient was generated along the same direction, whereby local void generation due to polymerization shrinkage could be suppressed or reduced. Furthermore, not only in the case of using a photocurable adhesive, but also by preventing the generation of voids in the adhesive layer by setting the direction of polymerization shrinkage in the adhesive layer to the direction along the surface including the adhesive layer. It was found that peeling of the adhesive could be reduced.

The present invention has the following configuration.

(Structure 1) A method of manufacturing an optical fiber array by fixing at least one end of an optical fiber with an adhesive while holding at least one of the ends of the optical fiber between an optical fiber fixing member and a holding member. An adhesive layer is interposed between the optical fiber fixing member and the pressing member, and the curing speed gradually decreases along the surface including the adhesive layer and from one side to the other side in the surface. Curing the adhesive so as to obtain an optical fiber array.

(Structure 2) In a method of manufacturing an optical fiber array by fixing the ends of a plurality of optical fibers to an optical fiber fixing member with an adhesive, the optical fiber fixing member and the An adhesive layer is interposed between the optical fiber ends, and the adhesive is applied along the surface including the adhesive layer and such that the curing speed gradually decreases from one side to the other side in the surface. A method for manufacturing an optical fiber array, comprising curing to obtain an optical fiber array.

(Structure 3) A method of manufacturing an optical fiber array by fixing at least one end of an optical fiber with an adhesive while holding at least one of the ends of the optical fiber between an optical fiber fixing member and a holding member. A light-curable adhesive layer is interposed between the optical fiber fixing member and the holding member,
A depression angle of −45 to 45 ° with respect to a side surface direction of the adhesive layer or a side surface direction of the adhesive layer and including a plane including the adhesive layer.
A method of manufacturing an optical fiber array, comprising irradiating light from a direction having an elevation angle to cure the adhesive layer to obtain an optical fiber array.

(Structure 4) In a method of manufacturing an optical fiber array by fixing the ends of a plurality of optical fibers to an optical fiber fixing member with an adhesive in a state of being arranged, the optical fiber fixing member and the A photocurable adhesive layer is interposed between the ends of the optical fibers, and a depression angle of −45 ° to 45 ° with respect to a side surface direction of the adhesive layer or a side surface direction of the adhesive layer and including a plane including the adhesive layer. -A method for manufacturing an optical fiber array, wherein an optical fiber array is obtained by irradiating light from a direction having an elevation angle to cure the adhesive layer.

(Structure 5) A method of manufacturing an optical fiber array by fixing at least one end of an optical fiber with an adhesive while holding at least one of the ends of the optical fiber between an optical fiber fixing member and a holding member. A light-curable adhesive layer is interposed between the optical fiber fixing member and the holding member,
Along the surface including the adhesive layer, and irradiating light so that the curing speed gradually decreases from one side to the other side in the surface, the adhesive is cured to obtain an optical fiber array. A method for manufacturing an optical fiber array, comprising:

(Structure 6) In a method of manufacturing an optical fiber array by fixing the ends of a plurality of optical fibers to an optical fiber fixing member with an adhesive in a state where the ends are arranged, the optical fiber fixing member and the A light-curing adhesive layer is interposed between the ends of the optical fibers, and the light is hardened along the surface including the adhesive layer and so that the curing speed gradually decreases from one side to the other side in the surface. And curing the adhesive to obtain an optical fiber array.

[0013]

[Action]

According to the above configuration 1, the direction of polymerization shrinkage in the adhesive layer is set to a direction along the surface including the adhesive layer, thereby preventing generation of voids in the adhesive layer and reducing peeling of the adhesive. it can. That is, by sequentially curing the adhesive in the direction along the surface including the adhesive layer, the polymerization direction is controlled, and the stress in the direction perpendicular to the plane including the adhesive layer (pressing member-adhesion) (A stress caused by polymerization shrinkage applied in a direction perpendicular to the interface between the agent layer and the interface between the optical fiber fixing member and the adhesive layer), thereby reducing the occurrence of peeling and voids. The adhesive may not be applied to the entire area between the optical fiber fixing member and the pressing member. In addition, in addition to the case where the adhesive layer is distributed in a planar shape,
This includes the case of linear distribution and the case of partial distribution.
The adhesive layer can be applied continuously or intermittently. The same effect can be obtained even when the adhesive distributed in a linear shape is sequentially cured along the line. The adhesive is not limited to a photocurable one. For example, a thermosetting adhesive may be used, and the adhesive may be sequentially cured in a direction along a surface including the adhesive layer by a temperature gradient. In the present invention, a mode in which both ends of the end of the optical fiber are sandwiched is also included. As shown in FIG. 4, the direction from one side to the other side in the plane including the adhesive layer is a direction A parallel to the length direction of the fiber 3, a direction C perpendicular to this direction, or a direction intersecting the direction. (Eg, diagonal direction B intersecting at 45 degrees). Also, in the direction from one side to the other side in the plane including the adhesive layer, a direction radially spreading from the center of the holding member toward the outer periphery thereof, or conversely, a direction from the outer periphery of the holding member toward the center thereof. Embodiments are also included.

In the above configuration 2, the pressing member is not required. There are a plurality of optical fibers arranged. Other than that, it has the same configuration as the above configuration 1, and the same effect as the above configuration 1 is obtained.

The third aspect is an aspect of the first aspect, in which a photocurable adhesive is used as an adhesive, and a direction in which the adhesive cures is controlled by a light irradiation direction. is there. Specifically, for example, as shown in FIG.
By irradiating light from the side direction of the photocurable adhesive layer, the adhesive is sequentially cured in the direction along the surface including the adhesive layer. It should be noted that a depression angle of −45 ° to 45 ° with respect to a plane including the adhesive layer in the side direction of the photocurable adhesive layer.
By irradiating light from the direction having the elevation angle,
An equivalent effect can be obtained. In this case, since the distance from the light source changes, the illuminance also has a gradient, and as a result, the curing speed can be controlled. Examples of the adhesive that can be cured by light include an epoxy adhesive and an acrylate adhesive. Except for these, it has the same configuration as the above configuration 1, and the same effects as the above configuration 1 can be obtained.

In the above configuration 4, the pressing member is not required. There are a plurality of optical fibers arranged. Other than that, it has the same configuration as the above configuration 3, and the same effect as the above configuration 3 is obtained.

Configuration 5 is an embodiment of Configuration 1 in which a photocurable adhesive is used as an adhesive and the direction in which the adhesive cures is controlled.
The light irradiation direction is not limited as in the above. In particular,
For example, as shown in FIG. 5, by irradiating light 6 in a slit shape from a direction perpendicular to the plane including the adhesive layer 4 and moving the irradiated portion, the light 6 is moved in the direction along the surface including the adhesive layer. The adhesive is cured sequentially. This method is suitable for automation. The irradiation part is moved by moving the optical fiber array 10 in, for example, the D direction or by moving a slit-shaped irradiation light source. Except for these, it has the same configuration as the above configuration 1, and the same effects as the above configuration 1 can be obtained.

In the above configuration 6, the pressing member is not required. There are a plurality of optical fibers arranged. Otherwise, it has the same configuration as configuration 5 above, and the same effects as configuration 5 are obtained.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 2 and 3, an 8-core tape fiber 3, which has been cleaned by removing primary and secondary coatings of a predetermined length from the tip, and a fiber having a V-groove for arranging the fibers. The fixing member 1 and the pressing member 2 for pressing the arranged fibers were filled with a commercially available ultraviolet curable adhesive 4 in the bonding portion, and were temporarily fixed by a jig.

As shown in FIG. 1, the temporarily fixed optical fiber array was irradiated with UV from the direction in which the fiber 3 was extended in the longitudinal direction to cure the adhesive (Example 1). As a comparative example, the temporarily fixed optical fiber array is irradiated with UV from a direction perpendicular to a plane including the adhesive layer 4, as shown in FIGS.
The adhesive was cured (Comparative Example 1).

The cured adhesive layer of the optical fiber array assembled as described above is applied to the optical fiber array by using an optical microscope.
Observed at 1 × magnification. Table 1 shows the results of void observation of the adhesive layer observed after assembling the optical fiber array.

[0023]

[Table 1]

As shown in Table 1, no void was generated in the optical fiber array (Example 1) assembled according to the present invention, but the size was 20 to 40 μm in the optical fiber array (Comparative Example 1) assembled according to the prior art. An uncountable number of voids were generated.

Next, the optical fiber arrays according to Example 1 and Comparative Example 1 were placed in a high-temperature and high-humidity state at a temperature of 75 ° C. and a humidity of 90% RH by an environmental tester. Was observed with an optical microscope at a magnification of 50 to 500 times. Table 2 shows the results of observation of peeling when the optical fiber array was placed in a high temperature and high humidity state.

[0026]

[Table 2]

As shown in Table 2, the peeled area of the optical fiber array assembled according to the present invention (Example 1) in a high-temperature, high-humidity state was higher than that of the optical fiber array assembled according to the prior art (Comparative Example 1). Percentage was small.

Next, the end face of the fiber array of the optical fiber array according to Example 1 and Comparative Example 1 was machined at an angle of 8 °, and then connected to a 1 × 8 waveguide to form a 1 × 8 beam splitter. A high-temperature and high-humidity test at 90 ° C. and a humidity of 90% RH was performed, and loss values were compared at predetermined time intervals. Table 3 shows the results of the high-temperature and high-humidity test using the beam splitter.

[0029]

[Table 3]

As shown in Table 3, the optical fiber array assembled according to the present invention (Example 1) was compared with the optical fiber array assembled according to the prior art (Comparative Example 1) in a high temperature and high humidity test in a beam splitter. The service life was much longer.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the scope of the above embodiments.

For example, a member made of glass transparent to ultraviolet rays can be used as the optical fiber fixing member and the holding member. Further, the optical fiber fixing member and the holding member need not be transparent to light for curing the adhesive.

When the optical fiber fixing member or the pressing member transmits light for curing the adhesive, the light (for example, ultraviolet light) for curing the adhesive is sufficiently narrow in comparison with the distribution of the adhesive. By irradiating the light through a member that transmits light, sequentially moving the irradiation position and sequentially curing the photocurable adhesive, the polymerization direction of the adhesive can be controlled, and the effect of the present invention can be obtained. With this configuration, the light irradiation can be performed as part of the flow of the movement of the irradiation position, so that the productivity can be improved. When both the optical fiber fixing member and the pressing member transmit light, the adhesive may be locally irradiated with light from both sides of the optical fiber fixing member and the pressing member to perform curing. The same applies to an optical fiber array having no holding member.

The groove for arranging the fibers is V
Not limited to the U-shape, other cross-sectional shapes such as a U-shape and a U-shape can be adopted.

[0035]

According to the method of manufacturing an optical fiber array of the present invention, it is possible to prevent the occurrence of voids in the adhesive layer and to reduce the peeling of the adhesive. As a result, the rate of rejection in the environmental test is reduced, the yield can be improved, and the productivity can be improved. Further, according to the present invention, it is possible to provide an optical fiber array that can maintain its performance under severe environments or long-term use and can withstand long-term use.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a method for manufacturing an optical fiber array according to one embodiment of the present invention.

FIG. 2 is a front view schematically showing an optical fiber array.

FIG. 3 is a sectional view taken along line II of FIG. 2;

FIG. 4 is a plan view schematically showing an optical fiber array.

FIG. 5 is a side view for explaining a method of manufacturing an optical fiber array according to another embodiment of the present invention.

FIG. 6 is a front view for explaining a conventional optical fiber array manufacturing method.

FIG. 7 is a sectional view taken along line II of FIG. 6;

[Explanation of symbols]

 Reference Signs List 1 optical fiber fixing member 2 holding member 3 optical fiber 4 adhesive 5 ultraviolet ray 6 light 10 optical fiber array

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kaoru Kagami 2-7-5 Nakaochiai, Shinjuku-ku, Tokyo Inside the Hoya Corporation (72) Inventor Kenji Yamanaka 2-7.5-5, Nakaochiai, Shinjuku-ku, Tokyo F-term in Hoya Corporation (reference) 2H036 JA04 LA03 MA04 NA01 PA11 PA14 2H038 AA51 CA52

Claims (6)

[Claims] 1. A method for manufacturing an optical fiber array by fixing at least one of the ends of an optical fiber between an optical fiber fixing member and a holding member and fixing the end with an adhesive. An adhesive layer is interposed between the optical fiber fixing member and the holding member so that the curing speed gradually decreases along the surface including the adhesive layer and from one side to the other side in the surface. Curing the adhesive to obtain an optical fiber array. 2. A method of manufacturing an optical fiber array by fixing an end of a plurality of optical fibers to an optical fiber fixing member and fixing them with an adhesive, wherein the optical fiber fixing member and the optical fiber An adhesive layer is interposed between the end portions, and the adhesive is cured along the surface including the adhesive layer and such that the curing speed gradually decreases from one side to the other side in the surface. A method for producing an optical fiber array. 3. A method of manufacturing an optical fiber array by fixing at least one end of an optical fiber between an optical fiber fixing member and a holding member with an adhesive and holding the end of the optical fiber. A photo-curable adhesive layer is interposed between the optical fiber fixing member and the holding member, and is -45 with respect to a side surface direction of the adhesive layer or a side surface direction of the adhesive layer and including the adhesive layer. A method for manufacturing an optical fiber array, comprising irradiating light from a direction having a depression angle and an elevation angle of up to 45 ° to cure the adhesive layer to obtain an optical fiber array. 4. A method of manufacturing an optical fiber array by fixing an end of a plurality of optical fibers to an optical fiber fixing member and fixing them with an adhesive, wherein the optical fiber fixing member and the optical fiber A photocurable adhesive layer is interposed between the ends, and a depression angle / elevation angle of −45 ° to 45 ° with respect to a side surface direction of the adhesive layer or a side surface direction of the adhesive layer and including a plane including the adhesive layer. Irradiating light from the direction having the above to cure the adhesive layer, thereby obtaining an optical fiber array. 5. A method of manufacturing an optical fiber array by fixing at least one end of an optical fiber with an adhesive while holding at least one of the ends of the optical fiber between an optical fiber fixing member and a holding member, A light-curable adhesive layer is interposed between the optical fiber fixing member and the pressing member, and the curing speed gradually increases along the surface including the adhesive layer and from one side to the other side in the surface. A method for manufacturing an optical fiber array, comprising irradiating light so as to decrease the amount of the adhesive and curing the adhesive to obtain an optical fiber array. 6. A method of manufacturing an optical fiber array by fixing an end of a plurality of optical fibers to an optical fiber fixing member and fixing them with an adhesive, wherein the optical fiber fixing member and the optical fiber A light-curing adhesive layer is interposed between the ends, and light is irradiated along the surface including the adhesive layer and so that the curing speed gradually decreases from one side to the other side in the surface. Curing the adhesive to obtain an optical fiber array.