JP2001116953A - Optical connector ferrule and method for attaching optical fiber to it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce hardening time of an adhesive needed for fixing an optical fiber to an optical connector ferrule. SOLUTION: In attaching the optical fiber to the optical connector ferrule 1 having a hole 1c for inserting plural optical fibers and a recess 1f for injecting the adhesive; after a part of each optical fiber 2 is inserted into the hole 1c, the adhesive is injected from the opening 1g of the recess 1f; the adhesive 5 is injected in such a manner that the injected height in the recess if is 0.3-0.6 mm above the level formed by the center lines of the plural optical fibers, and then the adhesive 5 is hardened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of attaching an optical fiber to an optical connector ferrule having a plurality of optical fiber insertion holes and a concave portion for injecting an adhesive which is opened on a side surface, and an optical connector ferrule.

[0002]

2. Description of the Related Art An optical connector ferrule having a plurality of optical fiber insertion holes and a concave portion for injecting an adhesive which is opened on the side surface may be used as a ferrule for an F12 type multi-core optical fiber connector specified in JIS C5981. Are known.

FIG. 4 is a view showing an example in which an optical fiber is attached to the optical connector ferrule. FIG. 4 (A) is a front view, FIG. 4 (B) is a side view, and FIG. FIG. In FIG. 4, 1 is an optical connector ferrule, 1a is a small diameter portion, 1b is a large diameter portion, 1c is an optical fiber insertion hole, 1d
Is a guide pin hole, 1e is an optical fiber core wire introduction hole, 1f is a concave portion for injecting an adhesive, 1g is an opening portion, 2 is an optical fiber, 3
Is an optical fiber, 4 is a boot, and 5 is an adhesive.

[0004] The optical connector ferrule 1 is a plastic molded product made of polyphenylene sulfide resin (PPS resin) or the like, and has a plurality of optical fiber insertion holes 1c arranged in parallel with each other.
And a concave portion 1f for injecting an adhesive and an optical fiber core wire introduction hole 1e. The concave portion 1f for injecting the adhesive is opened on the side surface of the optical connector ferrule 1 and has an opening 1g. Each of the optical fiber insertion holes 1c includes a small-diameter portion 1a having an inner diameter of about 126 μm on the distal end side and a large-diameter portion 1b having a larger inner diameter. Further, the optical fiber 2 is provided with a wire covering thereon to form a wire, and a plurality of the wires are arranged in parallel and collectively covered to form a tape-shaped optical fiber core wire 3.

[0005] When attaching an optical fiber to the optical connector ferrule, first, at the end of the optical fiber core 3, the collective covering and the covering of the individual wires are removed to expose a plurality of optical fibers 2. The exposed end of the optical fiber on the optical fiber side is inserted into the optical connector ferrule 1 from the optical fiber introduction hole 1 e through a boot 4 made of synthetic rubber or the like through the optical fiber core 3. The distal ends are respectively inserted into the optical fiber insertion holes 1c. At this time, the large diameter portion 1b is inserted into the optical fiber insertion hole 1c.
Since the optical fiber 2 is inserted from the side, the insertion operation is easy. The distal end of the optical fiber 2 is inserted until it protrudes slightly from the optical fiber insertion hole 1c. Then
The boot 4 is moved to the terminal side of the optical fiber core 3, and a part of the boot 4 is inserted between the inner wall surface of the optical fiber core introduction hole 1 e and the optical fiber core 3.

The insertion portion of the optical fiber 2 moves in the optical connector ferrule 1 or the optical connector ferrule 1
The optical connector ferrule 1 and the optical fiber core wire 3 are gripped by an appropriate gripping jig so that the optical fiber 2 does not fall off from the opening, and the adhesive injection concave portion 1f is opened through the opening 1g.
The adhesive 5 is injected and filled therein. At this time, the adhesive 5 is applied to the optical fiber 2 in the large diameter portion 1b in the optical fiber insertion hole 1c.
Is also filled around. In FIG. 1B, illustration of the adhesive is omitted.

After filling the adhesive up to the surface of the opening 1g,
The optical connector ferrule 1 and the optical fiber core 3 are held for several minutes while being held by a holding jig, and the adhesive is cured. Thereafter, the optical connector ferrule 1 and the optical fiber core wire 3 are removed from the holding jig, and the portion of the optical fiber 2 protruding from the optical fiber insertion hole 1c of the optical connector ferrule 1 is removed.
And the tip surface of the optical fiber 2 and the tip surface of the optical connector ferrule 1 are precisely polished.

[0008]

In attaching an optical fiber to an optical connector ferrule of the prior art, the optical fiber is inserted into the optical connector ferrule and fixed with an adhesive as described above. The tip face and the tip face of the optical fiber were precisely polished. On the other hand, recently, the tip surface of the optical fiber has been cut into a mirror surface, the tip surface of the optical fiber has been inserted into the optical connector ferrule according to the tip surface, and adhesively fixed, thereby eliminating the polishing of the end surface after bonding and fixing. Non-polishing type optical connectors have been proposed.

In this case, if a cyanoacrylate-based instantaneous adhesive is used as the adhesive, the time required for curing the adhesive can be reduced, so that the polishing time can be reduced and the work of attaching the optical fiber to the optical connector ferrule can be performed. Time is becoming much shorter. However, even with the use of an instant adhesive, there is no instantaneous curing in a few seconds to a few tens of seconds, and a curing waiting time of several minutes is required. Since the holding jig cannot be removed during this waiting time, the next mounting operation cannot be performed unless another holding jig is prepared. Therefore, a further reduction in the curing time has been required.

The inventors of the present invention have made various investigations and found that the optimum amount of the adhesive which can accelerate the curing time while ensuring the adhesive fixation is about 1.about.1 in the depth of the adhesive injection recess of the optical connector ferrule. It was found that it was considerably less than 3 mm, and the method of attaching an optical fiber to the optical connector ferrule and the optical connector ferrule of the present invention were reached.

[0011]

According to the present invention, there is provided a method for attaching an optical fiber to an optical connector ferrule, comprising a plurality of optical fiber insertion holes parallel to each other, and communicating with the optical fiber insertion holes to form openings on the side surfaces. The method for attaching an optical fiber to an optical connector ferrule having a recess for injecting adhesive, comprising: inserting a part of an optical fiber into each of the plurality of optical fiber insertion holes; After injecting the adhesive from the portion until the height of the adhesive is 0.3 mm to 0.6 mm higher than the plane formed by the center lines of the plurality of optical fibers, the adhesive is cured. Let it.

Further, in order to facilitate the work of injecting the adhesive, a mark may be formed on the wall surface of the concave portion for injecting the adhesive. Thus, the injection amount of the adhesive is set to 0.3 mm to 0.6 m.
By setting the height to m, the curing time of the adhesive before the optical fiber is bonded and fixed to the optical connector ferrule can be reduced to about 30 seconds.

[0013]

FIG. 1 is a view for explaining an embodiment of a method for attaching an optical fiber to an optical connector ferrule according to the present invention. FIG. 1 (A) is a front view, and FIG. 1 (B) is a side view. FIG. 1 (C) is a longitudinal sectional view. 1, the same reference numerals as those in FIG. 4 denote the same components, and a duplicate description will be omitted. Note that in FIG. 1B, as in FIG.
Illustration of the adhesive 5 is omitted. Reference numeral 1h denotes a mark for injecting the adhesive, which is a projection provided on the wall surface of the concave portion 1f for injecting the adhesive.

In the optical connector ferrule according to the present invention, the mark 1h for injecting the adhesive is placed on the side closer to the opening 1g than the plane formed by the center lines of the plurality of optical fiber insertion holes 1c.
It is provided on the wall surface of the concave portion 1f for injecting the adhesive at a position separated by from mm to 0.6 mm. The mark may be any protrusion such as a protrusion protruding from the wall surface or a line of a convex or concave line provided on the wall surface, as long as it can be easily visually confirmed.

In attaching the optical fiber to the optical connector ferrule of the present invention, a plurality of wires are first removed at once at the terminal of the optical fiber core wire 3 and by removing the wire coating of each wire at the end of the optical fiber core 3. Is exposed. In the case of the non-polishing method, the tip of the optical fiber 2 is cut into a mirror surface. In the case of the polishing method, there is no need to perform mirror cutting.

Next, the exposed end of the optical fiber 2 is inserted into the optical connector ferrule 1 through the boot 4 through the optical fiber core wire 3, and the tips of the plurality of optical fibers 2 are respectively inserted into the optical fiber insertion holes 1c. Let it. In the case of the non-polishing type, the mirror-cut end surface of the optical fiber is aligned with the end surface of the optical connector ferrule. In the case of the polishing type, the optical fiber is made to slightly protrude from the end face of the optical connector ferrule, and after protruding, the protruding portion is cut.

After the insertion of the optical fiber, an adhesive is injected into the adhesive injection recess 1f from the opening 1g, and the adhesive 5 is exposed from the optical fiber insertion hole 1c to the adhesive injection recess 1f side. The gap between the optical fiber 2 and the optical fiber 2 is filled around the optical fiber and the inner wall of the optical fiber insertion hole 1c. At this time, the upper surface of the injected adhesive 5 is set at a position 0.3 mm to 0.6 mm higher than the plane formed by the center lines of the optical fibers 2 arranged in parallel. In order to minimize the time required for curing, it is desirable to use a cyanoacrylate adhesive as the adhesive. Further, dropping a curing accelerator obtained by dissolving an amine or the like in ethanol onto the adhesive 5 to accelerate the curing of the adhesive is effective in further shortening the time.

When an optical connector ferrule provided with a mark 1h is used, the adhesive 5 may be injected up to the mark 1h. Also, an optical connector ferrule without a special mark can be used in the method of attaching an optical fiber to the optical connector ferrule of the present invention. In the case of an optical connector ferrule not provided with such special marks, the height of the adhesive 5 is set to 0.3 mm to 0.6 mm based on molding steps provided for other purposes, edges of boots, and the like. What is necessary is just to inject an adhesive so that it may become. Also, the height of the adhesive is 0.3m according to the size of the optical connector ferrule.
The injection amount may be determined in advance so as to be from m to 0.6 mm, and the adhesive may be housed in a fixed-rate injection type container and used to perform a predetermined amount of injection.

The reason for setting the height of the adhesive to 0.3 mm to 0.6 mm is as follows. FIG. 2 is a graph showing the relationship between the amount of the adhesive, the pull-out strength of the adhesively fixed optical fiber, and the curing time of the adhesive at room temperature, which was obtained in the process of studying the appropriate amount of the adhesive. This graph shows the case where the number of optical fibers is eight. Since the curing time of the adhesive is a waiting time for the operation, it is desirable that the time be as short as possible, but about 30 seconds is permissible. Accordingly, it can be seen from FIG. 2 that the amount of the adhesive should be 0.010 g or less in order to reduce the curing time of the adhesive to 30 seconds or less.

For the purpose of stably fixing the optical fiber to the optical connector ferrule, the force for pulling out the bonded and fixed optical fiber toward the optical fiber core, that is, the higher the pull-out strength of the optical fiber, is. Is good, but 6kg is enough. Therefore, in order to increase the pull-out strength of the optical fiber to 6 kg or more, the amount of the adhesive is 0.005 from FIG.
It can be seen that it is better to set it to g or more. From these results,
The optimum range satisfying both the curing time and the pull-out strength of the adhesive is 0.005 g to 0.010 g in the amount of the adhesive.

FIG. 3 is a graph showing the relationship between the amount of adhesive and the height of the adhesive from the plane defined by the center lines of the plurality of optical fibers when the number of optical fibers is eight. . According to this graph, the amount of the adhesive is 0.005 g.
In order to make the range of 0.010 g, the height of the adhesive is set to 0.1.
It can be seen that the distance should be in the range of 3 mm to 0.6 mm.
These adhesive amounts are shown for the case where the number of optical fibers is 8, and the adhesive amount changes almost proportionally with the number of optical fibers of the optical connector ferrule, but the height of the adhesive is It is not related to the number of optical fibers. Therefore, in the present invention, the appropriate range is defined by the height of the adhesive.

As described above, when the adhesive is injected into the adhesive recess of the optical connector ferrule, the height of the adhesive is set to 0.3 mm.
~ 0.6 mm, an example of shortening the adhesive curing time was shown, but if the adhesive around the optical fiber is cured, even if the holding jig holding the optical connector ferrule and the optical fiber core wire is removed. The optical fiber does not come off. Therefore, when the adhesive in the portion having a height of 0.3 mm to 0.6 mm is cured, the holding jig can be removed and the holding jig can be used for the next mounting operation.

If the space above the cured adhesive in the adhesive recess is not expected to be unfavorable due to external optical effects or the like if the space is left open, the upper space is replaced with another adhesive. , A filler, a lid, or the like. In the filling of the upper space with an adhesive, a filler or the like,
There is no need for the gripping jig used for the injection and curing of the adhesive. Therefore, the time required for curing the adhesive, filler and the like in the upper space can be used for attaching the optical fiber to the next optical connector ferrule, and does not become a waiting time for the operation.

[0024]

The method for attaching an optical fiber to an optical connector ferrule according to the present invention provides a method for attaching an optical fiber to an optical connector ferrule having a plurality of optical fiber insertion holes and a recess for injecting an adhesive. After inserting a part of the optical fiber into each of the fiber insertion holes, an adhesive is injected from the opening of the adhesive injection recess, and the injection height of the adhesive in the adhesive injection recess is adjusted by a plurality of optical fibers. Since the adhesive is injected and cured up to a height of 0.3 mm to 0.6 mm from the plane formed by the center line of the center line, the time required for curing the adhesive is 30 seconds or less,
There is an effect that the waiting time of the work is reduced to about 1/3 to 1/2 of the related art.

Also, the distance between the center line of each of the plurality of optical fiber insertion holes of the optical connector ferrule is 0.3 mm or less.
If a mark such as a protrusion is provided on the wall surface of the adhesive injection recess at a position 0.6 mm away, the adhesive can be injected based on the mark, and the light to the optical connector ferrule according to the present invention can be injected. The fiber can be easily attached.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of a method for attaching an optical fiber to an optical connector ferrule of the present invention,
(A) is a front view, (B) is a side view, and (C) is a longitudinal sectional view.

FIG. 2 is a graph showing an example of the relationship between the amount of an adhesive, the pull-out strength of an optical fiber, and the curing time of the adhesive.

FIG. 3 is a graph showing an example of the relationship between the amount of adhesive and the height of the adhesive from a plane formed by the center lines of the optical fibers.

4A and 4B are diagrams illustrating a method of attaching an optical fiber to an optical connector ferrule according to a conventional technique, wherein FIG. 4A is a front view, FIG. 4B is a side view, and FIG.

[Explanation of symbols]

 1: optical connector ferrule 1a: small diameter portion 1b: large diameter portion 1c: optical fiber insertion hole 1d: guide pin hole 1e: optical fiber core wire introduction hole 1f: concave portion for adhesive injection 1g: opening portion 1h: adhesive injection Mark for use 2: Optical fiber 3: Optical fiber core wire 4: Boot 5: Adhesive

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomohiko Ueda 1 Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Toshiaki Kakii 1-Tagamachi, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric (72) Masaaki Takaya 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Shinji Nagasawa 2--3, Otemachi, Chiyoda-ku, Tokyo No. 1 Nippon Telegraph and Telephone Corporation F-term (reference) 2H036 JA02 QA12 QA23 QA24

Claims (2)

[Claims] 1. A method for attaching an optical fiber to an optical connector ferrule having a plurality of optical fiber insertion holes parallel to each other and having a concave portion for injecting an adhesive which is communicated with the optical fiber insertion hole and opened on a side surface side. After inserting a part of the optical fiber into each of the plurality of optical fiber insertion holes, an adhesive is injected from the opening of the adhesive injection recess into the center of the plurality of optical fibers. A method for attaching an optical fiber to an optical connector ferrule, comprising: injecting the adhesive up to a height of 0.3 mm to 0.6 mm from the plane formed by the wires, and then curing the adhesive. 2. An optical connector ferrule having a plurality of optical fiber insertion holes parallel to each other and having an adhesive injecting recess opened to the side surface in communication with the optical fiber insertion holes. 0.3 mm or more from the plane formed by the center line of the fiber insertion hole to the opening side of the adhesive injection recess
An optical connector ferrule, wherein a mark for injecting an adhesive is provided on a side wall portion of the adhesive injecting recess at a distance of 0.6 mm.