JP4692365B2 - Manufacturing method of optical connector - Google Patents

Description

The present invention relates to a method of manufacturing an optical connector for connecting optical fibers to each other.

As an optical connector for connecting optical fibers to each other, a high-density multi-fiber optical connector called an MT connector (Mechanically Transferable Connector) is known. This optical connector is connected to each other using guide pins, and is used for connecting 2 to 12 optical fiber ribbons or a plurality of optical fiber cords.
This optical connector is provided with a boot made of an elastic material at the rear end portion for the purpose of relaxing the bending force applied to the optical fiber and preventing an increase in transmission loss and disconnection due to local bending. However, when the optical connector is assembled, if the adhesive for fixing the optical fiber ribbon or the optical fiber cord flows around the optical fiber ribbon or the optical fiber cord in the boot and cures, the inside of the boot is also cured by the adhesive. Therefore, the inherent flexibility of the boot is impaired and the function of relaxing the bending force of the optical fiber is not exhibited.

  For this reason, the gap around the optical fiber cord is made small by forming independent cord holes into which the optical fiber cord can be inserted for each single core in the boot and inserting the optical fiber cord into these cord holes. However, suppression of the inflow of the adhesive into the gap is performed (for example, see Patent Document 1).

JP 2004457575 A

By the way, even in the optical connector having the above structure, if the clearance between the cord hole and the optical fiber cord is not appropriate with respect to the viscosity of the adhesive, the adhesive will capillarize into the gap around the optical fiber cord in the cord hole. Therefore, it is necessary to accurately manage the clearance between the cord hole and the optical fiber cord.
However, it is extremely difficult to form the cord hole with high accuracy in the boot, which is an elastic material, and if the clearance is small, it takes a lot of work to insert the optical fiber cord into each cord hole.
Even if the clearance between the cord hole and the optical fiber cord is accurately controlled, if a low-viscosity adhesive is used, the adhesive flows into the gap between the cord hole and the optical fiber, and after the ferrule or boot. It is difficult to sufficiently suppress leakage of the adhesive from the edge.

This invention aims to provide a manufacturing method capable of easily manufacturing an optical connector which can relieve the bending force of the optical fiber by the boot that has sufficient flexibility while preventing the leakage of adhesive It is said.

  The optical connector manufacturing method of the present invention is an optical connector manufacturing method in which an optical fiber is inserted into a fiber insertion hole of a ferrule and fixed by an adhesive, and the optical fiber is inserted into the fiber insertion hole. An insertion step, a resin filling step in which a resin material having elasticity is filled in a liquid state when solidified between the rear end side of the ferrule and the optical fiber, and the optical fiber and the fiber insertion in the ferrule. And an adhesive filling step of filling and solidifying the adhesive between the holes.

  The rear end side of the ferrule includes an open portion and a cover member that covers the open portion, the rear end side of the ferrule is opened, the optical fiber is inserted into the fiber insertion hole, and the resin material is It is preferable to further include a step of attaching the lid member to the ferrule after filling.

  Further, a mounting step of attaching a mold member for adjusting the shape of the resin material to the rear end side of the ferrule in a state of being positioned in advance on the ferrule, and filling the resin material and solidifying the resin material, the mold member is And a removal step of removing from the ferrule.

According to the manufacturing method of the optical connector of the present invention, it is possible to easily manufacture the optical connector that can be alleviated bending force of the optical fiber by the boot that has sufficient flexibility while preventing the leakage of adhesive it can.

Hereinafter, an optical connector and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings.
1 is a perspective view of an optical connector according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of the optical connector shown in FIG. 1, and FIG. 3 is a plan view of the optical connector shown in FIG.
As shown in the figure, the optical connector 1 has a ferrule 2 made of an injection-molded product made of a synthetic resin material such as epoxy resin or PPS (polyphenylene sulfide), for example. A plurality of optical fiber insertion holes (fiber insertion holes) 3 are formed. In these optical fiber insertion holes 3, optical fiber core wires (optical fibers) 5 that have been shed from an optical fiber cord (optical fiber) 4 are inserted.

  The optical fiber cord 4 is, for example, an optical fiber core wire 5 having a diameter of 125 μm coated with a resin (coating diameter 250 μm), and arranged with 12 cores (only 6 cores are shown in FIG. 1) at a pitch of 250 μm. The fiber insertion hole (fiber insertion hole) 6 and the optical fiber introduction hole (fiber insertion hole) 7 formed in the ferrule 2 so as to communicate with the optical fiber insertion hole 3 are coated with a coating at the tip thereof. Removed and inserted.

The optical fiber introduction hole 7 of the ferrule 2 holds a boot 11 serving as a resin material portion according to the present invention, and a part of the boot 11 protrudes from the rear end of the ferrule 2. The boot 11 is made of an elastic material and is integrally formed around the optical fiber cord 4.
A window hole 12 communicating with the internal space 2a through which the optical fiber cord 4 is inserted in the ferrule 2 is formed on the upper surface of the ferrule 2. An adhesive is provided in the internal space 2a and the window hole 12 of the ferrule 2. 13 is filled. The optical fiber cord 4 inserted into the ferrule 2 is fixed by the adhesive 13.

The ferrule 2 is provided with guide holes 14 for positioning and connecting the optical connectors 1 on both sides thereof in parallel with the optical fiber insertion hole 3, the optical fiber insertion hole 6, and the optical fiber introduction hole 7. Yes.
Then, a guide pin (see reference numeral 45 in FIG. 5) is inserted and fixed in advance in the guide hole 14 of one ferrule 2 of the optical connector 1 connected to each other, and this guide pin is attached to the ferrule 2 of the other optical connector 1. By inserting into the guide hole 14 and abutting the connection surfaces 15 formed of end faces of the optical connector 1, the plurality of optical fiber core wires 5 are positioned relative to each other, and the optical fiber core wires are collectively connected.

Next, the case where the optical connector 1 is manufactured will be described along the manufacturing process shown in FIG.
As shown in FIG. 4A, first, the coated portion at the tip of the optical fiber cord 4 is peeled off, and each optical fiber core wire 5 is processed to be opened. The optical fiber cord 4 is connected to the optical fiber introduction hole of the ferrule 2. A fiber insertion step of inserting from 7 and inserting into the optical fiber insertion hole 3 through the optical fiber insertion hole 6 is performed.

Next, as shown in FIG. 4B, a resin material that has a high-viscosity liquid state in the optical fiber introduction hole 7 of the ferrule 2 on the rear end side of the ferrule 2 and that becomes an elastic body after curing. A resin filling step of filling a predetermined amount is performed. In addition, this resin material is filled in a state that protrudes from the rear end of the ferrule 2.
When the resin material is cured, the optical fiber introduction hole 7 of the ferrule 2 is irradiated with a boot 11 made of an elastic material obtained by curing the resin material in a state where a part protrudes from the rear end of the ferrule 2. It is integrally formed around the fiber cord 4.

Here, as the resin material used as the boot 11, the viscosity of the liquid before curing is in the range of 1 to 50 Pa · s, and the hardness of the solid after curing is in the range of 30 to 100 (JIS K6253). Alternatively, a thermosetting resin mainly containing a silicone material or a UV curable resin is preferable.
Although the thickness of the boot 11 depends on the hardness of the boot 11, it is preferably about 0.1 to 1.0 mm, and the protruding amount from the rear end of the ferrule 2 is preferably about 0.5 to 5 mm. .

Here, when forming the boot 11 which fills the resin material and becomes the resin material portion, it is preferable to use the mold member 41 shown in FIG.
The mold member 41 includes an insertion hole 42 through which the optical fiber cord 4 is inserted, a molding recess 43 that molds a part of the boot 11 protruding from the rear end of the ferrule 2, and a blockade that seals the upper surface of the molding recess 43. The mold member 41 is provided with positioning holes (not shown) into which the guide rod 45 inserted from the rear end side of the ferrule 2 can be inserted into the guide hole 14 of the ferrule 2 on both sides thereof. Yes.

When the boot 11 is formed using the mold member 41, the optical fiber cord 4 is passed through the insertion hole 42 of the mold member 41, and the guide hole from the rear end side of the ferrule 2 is inserted into the positioning hole of the mold member 41. 14, the mold member 41 is positioned and supported at the rear end portion of the ferrule 2, and the upper surface of the molding concave portion 43 is blocked by the sealing plate 44 (mounting process).
In this state, the optical fiber introduction hole 7 is filled with a resin material and the lid member 53 is attached. If it does in this way, the resin material extruded from the optical fiber introduction hole 7 will enter into the shaping | molding recessed part 43 of the type | mold member 41. FIG.
And when this resin material hardens | cures, while removing the sealing board 44, the removal process which removes the type | mold member 41 from the ferrule 2 is implemented.
In this way, the boot 11 on the rear end side of the ferrule 2 is molded into the shape of the space surrounded by the molding recess 43 and the sealing plate 44 by the mold member 41.

  In addition, it is preferable that the contact surface with the resin material of the mold member 41 and the sealing plate 44 is subjected to a surface treatment with good releasability for the resin material. In addition, a mold release agent may be applied to the contact surfaces of the mold member 41 and the sealing plate 44 with the resin material before the boot 11 is molded.

Next, as shown in FIG. 4C, the adhesive 13 is poured from the window hole 12 of the ferrule 2, and the adhesive 13 is filled and solidified by filling the inner space 2 a and the window hole 12 of the ferrule 2. Perform the process.
In this way, the optical fiber cord 4 and the optical fiber core wire 5 that has been spouted from the optical fiber cord 4 are fixed to the ferrule 2 by the adhesive 13 filled inside the ferrule 2 except for the filling region of the boot 11. The

At this time, even if the adhesive 13 flows into even a slight gap, the boot 11 filled in the optical fiber introduction hole 7 is around the optical fiber cord 4 even if it has a low viscosity of 100 mPa · s or less, for example. Therefore, it is possible to prevent such a problem that the adhesive 13 enters the periphery of the optical fiber cord 4 and leaks from the rear end side of the ferrule 2 or the boot 11.
As the adhesive 13, it is preferable to use a thermosetting or ultraviolet curable resin mainly composed of epoxy or cyano, and if it is an epoxy adhesive, it is used for bonding optical components such as Epoch 353ND. Agents are preferred.

  When the adhesive 13 is completely solidified, the connecting surface 15 consisting of the front end surface of the ferrule 2 is polished, the adhesive 13 leaking out from the optical fiber insertion hole 3 and solidified is removed, and the end face of the optical fiber core wire 5 is mirror-finished. Perform the finishing process to finish.

  By sequentially performing the above steps, the optical fiber cord 4 on the rear end side of the ferrule 2 is protected by the boot 11, and the bending force applied to the inner optical fiber core wire 5 is alleviated to increase transmission loss due to local bending. Thus, the optical connector 1 in which disconnection is prevented can be obtained.

  As described above, according to the optical connector and the manufacturing method thereof according to the first embodiment, the resin material having the elastic force in the solidified state is injected and filled in the rear end side of the ferrule 2. As a result, the boot 11 is formed integrally with the optical fiber cord 4, so that the optical fiber core wire 5 and the optical fiber cord 4 are inserted into the optical fiber insertion hole 3, the optical fiber insertion hole 6, and the optical fiber introduction hole 7. Even if a low-viscosity adhesive 13 is used, the adhesive 13 enters the gap between the optical fiber cord 4 and the boot 11 or leaks from the rear end side of the ferrule 2 or the boot 11. Thus, the bending force of the optical fiber cord 4 can be relaxed by the boot 11 having sufficient flexibility, and the optical connector 1 can be easily manufactured. It can be. That is, the boot 11 has a sealing function for preventing leakage of the adhesive 13 applied in a subsequent process in addition to the original function.

In particular, as a resin material for the boot 11, an epoxy or silicone material in which the viscosity of the liquid before curing is in the range of 1 to 50 Pa · s and the hardness of the solid after curing is in the range of 30 to 100 (JIS K6253). By using this, it is possible to improve the workability in the filling process to the ferrule 2 and to improve the leakage prevention effect of the adhesive 13.
Further, by using an epoxy resin or PPS (polyphenylene sulfide) that is relatively inexpensive and easy to mold as the ferrule 2, the cost of the optical connector 1 can be reduced.

Next, an optical connector according to a second embodiment of the present invention will be described.
Note that the same components as those of the optical connector of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
6A to 6C are cross-sectional views of the optical connector according to the second embodiment of the present invention.
In the second embodiment, only the shape of the boot 11 formed as the resin material portion in the first embodiment is different.
In FIG. 6 (a), the optical fiber introduction hole 7 of the ferrule 2 forms a recess 7a whose inner wall is recessed in the circumferential direction and enlarged in a position to be the tip of a boot 11A formed by injecting a resin material. is doing. Thus, when a resin material in a liquid state is injected before curing into the optical fiber introduction hole 7 through which the optical fiber cord (optical fiber) 4 is inserted on the rear end side of the ferrule 2, A boot 11A having a protruding portion is formed.
Further, when the resin injection amount is increased, as shown in FIG. 6B, it is possible to form a boot 11B in which the protruding portion comes to a portion displaced from the tip portion.
In FIG. 6C, the inner wall of the optical fiber introduction hole 7 is formed in a shape having a plurality of chevron shapes 7b, and a boot 11C is obtained by filling a resin material.

  The boots A to C filled and filled in the liquid state take any one of the above forms, thereby preventing inadvertent withdrawal from the optical fiber introduction hole 7 in a solidified state. The boot is not limited to the shape described above, and can take various forms. For example, the case where the above-mentioned concave part or convex part is formed in reverse may be sufficient. In particular, it is difficult to insert and fit a solid boot having a convex portion of a conventional form into an optical fiber introduction hole, but in the present invention, since it is injected and solidified in a liquid state, various shapes of boots are used. Can be formed.

Next, an optical connector and a manufacturing method thereof according to a third embodiment of the present invention will be described.
Note that the same components as those of the optical connector of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
FIG. 7 is a sectional view of an optical connector according to the third embodiment of the present invention, and FIG. 8 is a plan view of the optical connector shown in FIG.
In the optical connector 51 according to the third embodiment, as shown in the figure, an open portion 52 is formed on the surface of the ferrule 2 on the window hole 12 side, and the upper side of the optical fiber introduction hole 7 is open. ing. A lid member 53 can be attached to and detached from the opening 52.

In the optical connector 51, the optical fiber introduction hole 7 is formed in a state where the lid member 53 is attached to the open portion 52, and the optical fiber introduction hole 7 is integrally provided around the optical fiber cord 4. The boot 11 is held, and a part of the boot 11 protrudes from the rear end of the ferrule 2.
Here, the optical fiber cord 4 attached to the optical connector 51 is, for example, one in which 16 to 24 optical fiber core wires 5 having a diameter of 125 μm are arranged in parallel at a pitch of 125 μm and covered with a resin at a time. The optical fiber core wire 5 is inserted into the fiber insertion hole of the ferrule 2.

  Note that only the optical fiber insertion hole 6 is formed at the tip of the ferrule 2 of the optical connector 51, and the optical fiber cord 4 is attached with its tip inserted into the optical fiber insertion hole 6 without being covered. Is done.

Next, the case where the optical connector 51 is manufactured will be described along the manufacturing process shown in FIG.
As shown in FIG. 9A, the optical fiber cord 4 is inserted through the optical fiber introduction hole 7 of the ferrule 2 without subjecting the tip end thereof to a fiber insertion process.

  Next, as shown in FIG. 9B, a resin filling step of filling a predetermined amount of resin material into the opening 52 on the rear end side of the ferrule 2 is performed. The resin material is preferably filled so as to rise somewhat upward in the optical fiber introduction hole 7.

After filling the resin material, as shown in FIG. 9C, before the resin material is completely cured, an attaching process for attaching the lid member 53 to the opening 52 of the ferrule 2 from above is performed.
If it does in this way, the resin material with which the optical fiber introduction hole 7 was filled will be pushed in by the cover member 53, and will be extruded in the front-back direction of the ferrule 2 in the optical fiber introduction hole 7. FIG.

And when this resin material hardens | cures and becomes an elastic material, it has the elastic force integrated with the circumference | surroundings of the optical fiber cord 4 in the optical fiber introduction hole 7 of the ferrule 2 as shown in FIG.9 (d). Boot 11 is formed.
In addition, it is preferable to attach the mold member 41 described above to the rear end portion of the ferrule 2 and mold the resin material extruded from the rear end of the ferrule 2 by the mold member 41.

Next, as shown in FIG. 9 (d), the adhesive 13 is poured from the window hole 12 of the ferrule 2, and the adhesive 13 is filled into the internal space 2 a and the window hole 12 of the ferrule 2 to be solidified.
If it does in this way, the optical fiber cord 4 will be fixed to the ferrule 2 with the adhesive agent 13 with which the inside of the ferrule 2 except the filling area | region of the boot 11 was filled.

At this time, even if the adhesive 13 flows into even a slight gap, the boot 11 filled in the optical fiber introduction hole 7 is around the optical fiber cord 4 even if it has a low viscosity of 100 mPa · s or less, for example. Therefore, the adhesive 13 does not enter the periphery of the optical fiber cord 4 and leak from the rear end side.
As the adhesive 13, it is preferable to use a thermosetting or ultraviolet curable resin mainly composed of epoxy or cyano, and if it is an epoxy adhesive, it is used for bonding optical components such as Epoch 353ND. Agents are preferred.

When the adhesive 13 is completely solidified, the connection surface 15 formed of the tip surface of the ferrule 2 is polished, and the adhesive 13 leaked and solidified from the optical fiber insertion hole 6 is removed and the optical fiber cord of the optical fiber cord 4 is removed. The finishing process of mirror-finishing the end face of 5 is carried out.
By sequentially performing the above steps, the optical fiber cord 4 on the rear end side of the ferrule 2 is protected by the boot 11, and the bending force applied to the inner optical fiber core wire 5 is alleviated to increase transmission loss due to local bending. Thus, the optical connector 51 in which disconnection is prevented can be obtained.

  As described above, in the case of the optical connector and the manufacturing method thereof according to the third embodiment, as in the first embodiment, the resin material having an elastic force in a solidified state at the rear end side of the ferrule 2. Since the boot 11 is formed integrally with the optical fiber cord 4 by injecting and filling in a liquid state, an adhesive for fixing the optical fiber cord 4 to the optical fiber insertion hole 6 and the optical fiber introduction hole 7 Even if a low-viscosity material 13 is used, problems such as the adhesive 13 entering the gap between the optical fiber cord 4 and the boot 11 or leaking from the rear end side of the ferrule 2 or the boot 11 can be prevented. Thus, the bending force of the optical fiber cord 4 can be relaxed by the boot 11 having sufficient flexibility, and the optical connector 51 can be easily manufactured. . That is, the boot 11 has a sealing function for preventing leakage of the adhesive 13 applied in a subsequent process in addition to the original function.

  Moreover, since the opening part 52 is formed and opened on the rear end side of the ferrule 2 and is closed by the lid member 53 after the resin material to be the boot 11 is filled, the filling operation of the resin material is facilitated. Thus, the assembly workability of the optical connector 51 can be improved.

  In particular, when mounting the optical fiber cord 4 in which the optical fiber core wire 5 has an extremely small diameter for high-density mounting and wiring to a minute space, as shown in the third embodiment, the optical fiber cord It is preferable that the cover is attached as it is without removing the coating at the tip of 4 and performing a scouring process. This method is effective in increasing the density in order to cope with so-called optical interconnection, which is the optical wiring between the electronic devices or in the devices, specifically, high-speed transmission. It is suitable as an optical connector used for an optical fiber board used in equipment.

  In each of the above embodiments, the boot 11 is formed of a resin material, but an adhesive may be used as the resin material. Specific examples of the adhesive include epoxy-based DP005 (trade name) manufactured by 3M, and silicone-based adhesive KE45W (trade name) manufactured by Shin-Etsu Silicone, Toray Dow Corning. SE918 (trade name) or the like can be used.

  In the above-described embodiment, the case where a plurality of single-fiber optical fiber cords 4 are attached to the ferrule 2 has been described as an example. However, as a form of optical fiber that can be attached to the ferrule 2, a single-fiber optical fiber cord 4 Other examples include an optical fiber ribbon in which coated optical fibers are integrated with a common coating, or an optical fiber ribbon cord in which a protective coating is further provided on the optical fiber ribbon.

1 is a perspective view of an optical connector according to a first embodiment. It is sectional drawing of the optical connector shown in FIG. It is a top view of the optical connector shown in FIG. It is a figure explaining the manufacturing process of an optical connector. It is a perspective view explaining the type | mold member which shape | molds boots. (A)-(c) is sectional drawing of each optical connector which concerns on 2nd Embodiment. It is sectional drawing of the optical connector which concerns on 3rd Embodiment. It is a top view of the optical connector shown in FIG. It is a figure explaining the manufacturing process of an optical connector.

Explanation of symbols

1, 51 Optical connector 2 Ferrule 3 Optical fiber insertion hole (fiber insertion hole)
4 Optical fiber cord (optical fiber)
5 Optical fiber core (optical fiber)
6 Optical fiber insertion hole (fiber insertion hole)
7 Optical fiber holding hole (fiber insertion hole)
11, 11A, 11B, 11C Boots (resin material part)
13 Adhesive 41 Mold member 52 Opening part 53 Lid member

Claims (3)

A method of manufacturing an optical connector in which an optical fiber is inserted through a fiber insertion hole of a ferrule and fixed with an adhesive ,
A fiber insertion step of inserting the optical fiber into the fiber insertion hole, and a resin filling step of filling in a liquid state a resin material having elasticity when solidified between the rear end side of the ferrule and the optical fiber; And an adhesive filling step of filling and solidifying the adhesive between the optical fiber in the ferrule and the fiber insertion hole . The rear end side of the ferrule includes an open portion and a cover member that covers the open portion, the rear end side of the ferrule is opened, and the optical fiber is inserted into the fiber insertion hole and filled with the resin material. The method for manufacturing an optical connector according to claim 1, further comprising a step of attaching the lid member to the ferrule. A mounting step of attaching a mold member for adjusting the shape of the resin material to a rear end side of the ferrule in a state where the mold member is previously positioned on the ferrule; and filling the resin material and solidifying the resin material; The optical connector manufacturing method according to claim 1, further comprising a removing step of removing the optical connector from the optical connector.

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