JP3778124B2 - Manufacturing method of optical connector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method of an optical connector used for optical fiber connection.
[0002]
[Prior art]
In recent years, with the expansion of information transmission capacity, attention has been focused on the opticalization of information communication networks, and various optical connectors important for the construction of optical fiber communication networks for the realization thereof have been developed. In particular, an MT connector (Mechanically Transferable connector) developed for network equipment is a highly reliable multi-fiber optical connector that is widely used mainly in Japanese optical communication networks. This MT connector uses a guide pin to removably connect a pair of optical connector plugs, and is used to connect a 2 to 12 optical fiber ribbon or an optical fiber cord.
[0003]
In addition, there is a push-on pull-off simple detachable MPO connector based on an MT connector. FIG. 3 is a diagram showing an example of a conventionally known MPO connector, in which 1 is an optical connector plug, 2 is a connector housing, 3 is a ferrule, 4 is a multi-fiber optical fiber, 5 is a connector adapter, 6 is an optical fiber hole, 7 is a guide hole, and 8 is a guide pin.
[0004]
An optical connector plug 1 (hereinafter referred to as an optical plug) is configured by housing a ferrule 3 designed for an MT connector in a connector housing 2 and mounting a connection end of a multi-core optical fiber 4 on the ferrule 3. The The optical plug 1 is inserted into the fitting holes 5a provided on both sides of the connector adapter 5, and the insertion is latched by latch means (not shown). In the optical plugs 1 on both sides, the front wall surfaces of the ferrule 3 are abutted with each other to form an optical connection.
[0005]
The ferrule 3 is formed by resin molding, and has a plurality of optical fiber holes 6 and a pair of guide holes 7 on both sides thereof. Each optical fiber of the multi-core optical fiber core wire 4 is inserted into the optical fiber hole 6. Glued. In the guide hole 7, a guide pin 8 is inserted and fixed to one of the optical plugs connected to each other, and the connection with the other optical plug is positioned. The front wall 3a of the ferrule 3 is polished together with the optical fiber after the optical fiber is inserted.
[0006]
4A and 4B are diagrams for explaining conventional ferrule molding. FIG. 4A is a diagram showing a molding die, and FIG. 4B is a diagram showing a cross section of the molded ferrule. In the figure, 10 is a mold divided into two parts, 11 is a core, 12 is a lower mold, 13 is an upper mold, 14 is a guide hole forming pin, 15 is an optical fiber hole forming pin, and 16 is a fiber coating hole forming. , 17 is a fiber core hole forming part, 18 is a base, 19 is a V groove for a guide hole forming pin, 20 is a V groove for an optical fiber hole forming pin, and 21 is a forming cavity. Description of other reference numerals is omitted by using the same reference numerals as those in FIG.
[0007]
A ferrule molding die 10 shown in FIG. 4 includes a core 11, a lower die 12 divided into two, and an upper die 13. The core 11 is configured by providing a guide hole forming pin 14 and an optical fiber hole forming pin 15 on the front side of the base 18. Also, the latter half of the pin 15 is provided with a fiber coating hole forming portion 16 in which the fiber coating portion is accommodated somewhat thicker than the pin 15, and a block-like fiber in which a multi-core fiber core is accommodated behind the fiber coating hole forming portion 16 A core hole forming part 17 is provided.
[0008]
The lower mold 12 is configured by providing a guide hole forming pin V-groove 19 for positioning the guide hole forming pin 14 and an optical fiber hole forming pin V-groove 20 for positioning the optical fiber hole forming pin 15 in the front part. ing. The rear part is provided with a similar V-groove or the like for supporting the guide hole forming pins 14 at two points, and the center part is provided with a molding cavity 21 filled with molding resin. The upper mold 13 holds a guide hole forming pin 14 and an optical fiber hole forming pin 15 corresponding to the lower mold 12, and a forming cavity is formed in which a ferrule having a predetermined shape is formed.
[0009]
When molding is performed using the mold 10 described above, the ferrule 3 having a shape as shown in cross section in FIG. 4B is molded. The ferrule 3 is formed in a rectangular block shape having a front wall 3a and a side wall 3b, and after optical fibers are inserted and bonded to the optical fiber holes 6, the side walls 3b are pressed by a gripping tool to hold the front wall 3a, for example, 8 ° Polished to have a back and forth tilt.
[0010]
[Problems to be solved by the invention]
When a large amount of molding is performed by the above-described ferrule molding, lateral displacement occurs between the lower mold 12 and the upper mold 13 due to wear of the mold. Also, there may be a deviation in the initial stage even with a new mold. As shown in FIG. 5A, the shift of the mold causes a step in the ferrule side wall 3b in the dividing line 3c of the upper and lower molds.
[0011]
Polishing of the front wall 3a of the ferrule 3 is usually performed by gripping both side walls 3b with the gripping tool 23. However, as shown in FIG. It becomes impossible to perform, and it becomes a gripping state inclined. Then, if the front wall 3a is polished in the gripping state as shown in FIG. 5B, polishing at the correct angle cannot be performed. As a result, transmission loss increases due to the connection of the optical connector. A new mold may be used when the mold is worn, but if the mold has a short life, the cost increases. Moreover, in order to suppress the shift | offset | difference in an initial stage with a new metal mold | die, what is necessary is just to raise the precision of a metal mold | die, but this also increases cost.
[0012]
The present invention has been made in view of the above-described circumstances, and an optical connector having a ferrule shape that can stably perform gripping for polishing the front wall of the ferrule even if some wear occurs in the mold. It is an object of the present invention to provide a method for manufacturing a semiconductor device.
[0013]
[Means for Solving the Problems]
Method for manufacturing an optical connector according to the present invention, the optical fiber is attached to the ferrule having a guide hole and the optical fiber holes, a manufacturing method of an optical connector polished ferrule front wall, ferrule 2 minutes split has been formed the metal mold split line as a boundary to molding narrowing the one side wall width than the other side wall width, characterized in Rukoto. Further, the side wall you molding is narrow from the dividing line, and wherein the molding tapered.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. Figure 1 shows a ferrule of an optical connector according to the production method of the present invention, FIG. 1 (A) is a perspective view, FIG. 1 (B) and FIG. 1 (C) is a diagram illustrating a forming shape method, Figure 2 forming metal It is a figure which shows a type | mold. The reference numerals in the figure are the same as those used in FIGS.
[0016]
As shown in FIG. 3, the optical connector 1 according to the manufacturing method of the present invention houses a ferrule 3 designed for an MT connector in a connector housing 2 as shown in FIG. The ferrule 3 is configured by attaching a connection end of a multi-core optical fiber core wire 4. The optical plug 1 is inserted into the fitting holes 5a provided on both sides of the connector adapter 5, and the insertion is latched by latch means (not shown). In the optical plugs 1 on both sides, the front wall surfaces of the ferrule 3 are abutted with each other to form an optical connection.
[0017]
In the present invention, as shown in FIG. 1A, the width is narrower from one side (upper side in the example in the figure) than the other side (lower side in the figure) from the dividing line 3c of the ferrule side wall 3b. It is molded in a recess. The ferrule 3 itself is formed by resin molding as in the prior art, and has a plurality of optical fiber holes 6 and a pair of guide holes 7 on both sides thereof. The front wall 3a of the ferrule 3 is polished together with the optical fiber after the optical fiber is inserted.
[0018]
At the time of polishing the ferrule front wall 3a, the both side walls 3b of the ferrule are gripped with a gripping tool and polished as in the conventional case (see FIG. 5). In the present invention, since the upper side wall width from the dividing line 3c of the ferrule is narrowed, the gripping tool holds the wide side wall below the dividing line 3c from both sides. Since the lower side wall is formed by an accurate parallel surface by the lower mold 12, it can be gripped in a correct state by the gripping tool. As a result, the ferrule front wall 3a can be polished accurately and stably, and an optical connector with little increase in transmission loss can be obtained.
[0019]
Further, by forming the upper side wall width narrower from the dividing line 3c in advance, even if lateral displacement occurs between the lower mold 12 and the upper mold 13 due to wear of the mold, the range of lateral displacement is a ferrule. If it is in the range which the upper side wall was dented, a metal mold | die can be used continuously. As a result, the life of the mold can be extended, and the manufacturing cost can be reduced.
[0020]
The concave shape of the upper side wall of the ferrule 3 is such that the width of the cavity side wall of the upper mold 13 is smaller than the width of the cavity side wall of the lower mold 12 as shown in FIG. Can be formed. In FIG. 1B, the upper mold is designed so that the side wall above the mold dividing line 3c is narrower in parallel with the width D (one side) than the lower side wall surface. For this reason, the shoulder part of the difference width D arises in the ferrule side wall 3b. The shoulder width D is 1 μm to 20 μm, preferably 5 μm to 10 μm. If the difference width D is less than 1 μm, the substantial effect of avoiding the lateral deviation is small, and if it exceeds 20 μm, not only the lateral deviation of the mold but also wear in other parts cannot be ignored, which is not very meaningful.
[0021]
Further, as shown in FIG. 1C, the upper side wall that is formed narrower than the dividing line 3c of the mold can be formed in a tapered shape by narrowing the upper side. In this case, it can implement easily by making the side wall of the cavity of the upper metal mold | die 13 into an inclined surface. By making this side wall tapered, the mold release property of the upper mold 13 can be improved, and the stress applied to the mold pins of the core in the mold remaining in the lower mold 12 can be reduced. can do. The taper may be formed within the difference width D of the shoulder, but may be provided so as to be recessed in addition to the difference width D as shown in the figure. Since the taper improves the mold releasability, the taper angle θ may be about 1 ° to 3 °.
[0022]
FIG. 2 is a view showing an example of a molding die used for ferrule molding according to the present invention. The same reference numerals as those used in FIG. The molding die 10 of the ferrule 3 is composed of three members: a core 11, a lower die 12, and an upper die 13. The core 11 is configured by providing a guide hole forming pin 14 and an optical fiber hole forming pin 15 on the front side of the base 18. Also, the latter half of the pin 15 is provided with a fiber coating hole forming portion 16 in which the fiber coating portion is accommodated somewhat thicker than the pin 15, and a block-like fiber in which a multi-core fiber core is accommodated behind the fiber coating hole forming portion 16 A core hole forming part 17 is provided.
[0023]
The lower mold 12 is configured by providing a guide hole forming pin V-groove 19 for positioning the guide hole forming pin 14 and an optical fiber hole forming pin V-groove 20 for positioning the optical fiber hole forming pin 15 in the front part. ing. Further, the rear portion of the lower mold 12 is provided with a similar V-groove or the like for supporting the guide hole forming pins 14 at two points, and a molding cavity 21 filled with resin is provided at the central portion. The upper mold 13 holds a guide hole forming pin 14 and an optical fiber hole forming pin 15 corresponding to the lower mold 12, and is formed with a forming cavity 22 in which a ferrule having a predetermined shape is formed. The molding cavity 22 of the upper mold 13 has a side wall 22a formed inside the side wall 21a of the lower mold 13 and is formed with an inclined surface.
[0024]
When molding is performed using the above-described mold 10, the resin is filled so as to fill the voids of the molding cavity 21 and the core 11 of the lower mold 12 and the molding cavity 22 of the upper mold 13. Thereafter, by removing the mold 10, the side wall formed on the upper mold 13 side is recessed from the side wall formed by the lower mold 12 and the ferrule 3 having a narrow side wall shape is formed as shown in FIG. Is done.
[0025]
In addition, although the example in which the concave surface with the narrow width is formed on the upper mold 13 side is shown, it may be formed in the cavity 21 on the lower mold 12 side. However, in the case of forming a taper, it is preferable to provide an inclined surface for taper on the mold side that is to be released first. That is, when the mold is released, it is provided on the mold on the side where the core 11 does not remain. Thereby, in the state before mold release with the other mold, the stress generated at the time of mold release can be relieved in the guide hole forming pin 14 and the optical fiber hole forming pin 15 of the core 11. , It is possible to prevent the ferrule from causing distortion due to mold release.
[0026]
1, after inserting an optical fiber into the optical fiber hole 6, the ferrule side wall 3b is gripped by a gripping tool (see FIG. 5), and the front wall 3a is at a predetermined angle β. So that it is polished. This angle β is for preventing the reflected light at the connection interface of the optical connector from returning to the light source side, and is preferably formed in the range of 4 ° to 12 °, more preferably 8 °. It is good to do.
[0027]
【The invention's effect】
As is apparent from the above description, according to the present invention, the low-cost mold is used, and even if the mold is somewhat worn, the ferrule side wall to be gripped for polishing the front wall of the ferrule is parallel. It can be molded on a flat surface. Thereby, the front wall of the ferrule can be polished in a plane state at a correct angle, and a high-quality optical connector with little increase in transmission loss can be obtained. In addition, the service life of the mold can be extended, and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an embodiment of the present invention.
FIG. 2 is a view showing an example of a ferrule molding die used in the practice of the present invention.
FIG. 3 is a diagram illustrating an example of an optical connector.
FIG. 4 is a view showing an example of a conventional ferrule molding die.
FIG. 5 is a view showing a conventional ferrule forming example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Optical connector plug, 2 ... Connector housing, 3 ... Ferrule, 3a ... Ferrule front wall, 3b ... Ferrule side wall, 3c ... Dividing line, 4 ... Multi-core optical fiber core wire, 5 ... Connector adapter, 5a ... Fitting hole , 6 optical fiber holes, 7 guide holes, 8 guide pins, 10 molds, 11 cores, 12 lower molds, 13 upper molds, 14 guide hole forming pins, 15 optical fibers Hole forming pin, 16 ... Fiber covered hole forming part, 17 ... Fiber core hole forming part, 18 ... Base, 19 ... V groove for guide hole forming pin, 20 ... V groove for optical fiber hole forming pin, 21, 22 ... molding cavity, 21a, 22a ... side wall, 23 ... gripping tool.

Claims (2)

  An optical connector manufacturing method in which an optical fiber is attached to a ferrule having a guide hole and an optical fiber hole and the front wall of the ferrule is polished. A method of manufacturing an optical connector, wherein the side wall width is narrower than the other side wall width. The method for manufacturing an optical connector according to claim 1 , wherein the side wall to be narrowed is formed into a tapered shape.

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