KR100294116B1 - Method of ferrule of multi-fiber optical connector - Google Patents

Abstract

PURPOSE: A method for fabricating a ferrule for multi-core type optical connector is provided to form a ferrule for multi-core type optical connector used in an optical connector for connecting one optical fiber with the other optical fiber. CONSTITUTION: A material layer reacted with an X-ray is formed on a substrate. The material layer is formed with a PMMA(Poly-Methyl-Meth-Acrylate) or a resin layer. An exposure process is performed by using an X-ray mask patterned with a ferrule shape. The exposure process is performed by irradiating the X-ray to the material layer. The substrate is exposed by developing the exposed material layer. A material layer having an opposite shape of the ferrule is formed in the substrate. The exposed substrate is filled by a plating structure. The plating structure is flattened by performing a polishing process. The material layer is removed. A lower plate(81) of the ferrule is obtained by separating the plating structure. An upper plate of the ferrule is obtained by performing the above processes, repeatedly. The lower plate(81) is combined with the upper plate.

Description

Method of manufacturing ferrule for multi-core optical connector {Method of ferrule of multi-fiber optical connector}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a multicore optical connector, and more particularly, to a method of manufacturing a ferrule for a multicore optical connector used in an optical connector connecting between optical fibers.

In general, a multicore optical connector for connecting a multicore optical fiber is composed of a ferrule, a guide pin and a housing. Among them, the ferrule has a plurality of optical fiber alignment grooves, and each of these optical fiber alignment grooves is 1.5 to 2 탆 even if the loss due to reflection and scattering in the optical fiber cross section is ignored in order to satisfy the splice loss required by the international standard. Must have an alignment precision of. Furthermore, since the optical connector is a structure in which two connectors are coupled, each connector should have an alignment accuracy corresponding to half of the alignment accuracy, that is, an alignment precision within 1 μm.

Conventional ferrules for optical connectors make sophisticated V-shaped grooves on the surface of ceramic substrates by machining and use them as optical fiber alignment grooves or guide pin alignment grooves. However, the ferrule for the optical connector is difficult to adjust the alignment precision to less than 1㎛ because the ceramic substrate must be processed to a uniform depth and width in order to align a plurality of optical fiber alignment grooves for the optical fiber having a diameter of 125㎛ . In addition, since all the ceramic substrates need to be machined, there is a problem in that the price is high and the yield and productivity are lowered.

Another conventional optical connector ferrule for avoiding machining of the ceramic substrate wet-etched the silicon substrate to form a V-shaped optical fiber alignment groove, and then align the optical fiber using the same. Such ferrules for optical connectors do not require machining of ceramic substrates as in the prior art, but are difficult to mass-produce because they require precise control of the composition, temperature, and etching time of the etching solution to precisely etch vulnerable silicon substrates. There is a difficulty to provide a process equipment and a clean room for.

Accordingly, the technical problem of the present invention is to provide a method of manufacturing a ferrule for a multi-core optical connector that can solve the above problems.

1 is a perspective view showing the configuration of a multi-core optical connector comprising a ferrule manufactured by the present invention,

FIG. 2 is an enlarged view illustrating the ferrule of FIG. 1.

3 to 6 are cross-sectional views showing various shapes of the ferrule for multi-core optical connector manufactured by the present invention,

7A to 7D are views for explaining a method of forming a Riga mold by a Riga process applied to the present invention,

8a to 8c are views showing an example of a ferrule manufacturing method for a multi-core optical connector of the present invention using a Riga process,

9a to 9f are views showing another example of the ferrule manufacturing method for a multi-core optical connector of the present invention using a Liga process,

10A and 10B are views illustrating still another example of a ferrule manufacturing method for a multi-core optical connector of the present invention using a Liga process,

11A to 11E are cross-sectional views illustrating a Riga mold used in manufacturing the ferrule for the multi-core optical connector of FIG. 10B.

12A to 12D are views showing an example of a method for manufacturing a Riga mold used in manufacturing a ferrule for a multi-core optical connector of the present invention.

13A to 13D illustrate another example of a method of manufacturing a Riga mold used in manufacturing a ferrule for a multi-core optical connector of the present invention.

In order to achieve the above technical problem, the method of manufacturing a ferrule for a multi-core optical connector of the present invention comprises the steps of forming a material film capable of reacting with X-rays on a substrate, and the opposite shape of the ferrule shape on the material film is patterned into an absorber Exposing using an exposed X-ray mask, developing the exposed material film to expose the substrate, and forming a material film having an opposite shape of a ferrule therein, and filling a plating structure on the exposed substrate. Polishing the planarizing structure by polishing the planarizing structure, removing the material layer, and separating the plating structure to obtain a lower plate of the ferrule; repeating the preceding steps to obtain an upper plate of the ferrule; Combining the tops.

The substrate is one selected from a silicon substrate on which a plating base is formed, a glass substrate on which a plating base is formed, an alumina substrate on which a plating base is formed, and a metal substrate. The material film is formed of PMMA or resin film.

In addition, the method of manufacturing a ferrule for a multi-core optical connector of the present invention comprises the steps of forming a material film capable of reacting with X-rays on a substrate, and exposing the material film with an X-ray mask in which the shape of the ferrule is patterned with an absorber. And developing the exposed material film to form the ferrule shape so that a part of the surface of the substrate is exposed, plating the exposed substrate to form a plating structure, and polishing the plating structure. Planarizing, removing the material film, cutting the substrate to obtain a Riga mold made of a plating structure and a substrate, or separating the plating structure from the substrate to obtain a Riga mold, and Preparing a machining mold that can be assembled and injected, and the plastic injection box after assembling the Riga mold and the machining mold Thereby obtaining a bottom plate of the ferrule made of plastic, repeating the preceding steps to obtain a top plate of the ferrule, and combining the bottom plate and the top plate.

The ferrule for the multi-core optical connector manufactured by the present invention is composed of a lower plate having an optical fiber alignment groove and a guide pin alignment groove and an upper plate corresponding thereto, so that the optical fiber can be easily inserted. In addition, since the ferrule for an optical connector of the present invention is manufactured using a Liga process, a precision of 1 μm or less can be easily realized.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing the configuration of a multi-core optical connector including a ferrule manufactured by the present invention, Figure 2 is an enlarged view showing the ferrule of FIG.

Specifically, the multi-core optical connector manufactured by the present invention includes a ferrule 3 in which a plurality of optical fibers 1 are injected and aligned, and a guide pin 5 injected into the ferrule 3 to support the ferrule 3. ) And a housing 7 for supporting the ferrule 3 and the guide pin 5 from the outside.

In particular, the ferrule for an optical connector manufactured according to the present invention is divided into an upper plate 3a and a lower plate 3b, as shown in FIG. The upper plate 3a and the lower plate 3b are made of metal or resin. The reason why the ferrule 3 is divided into an upper plate 3a and a lower plate 3b is that a considerable difficulty in inserting an optical fiber having a diameter of 125 μm is formed when forming a single portion.

In detail, the lower plate 3b of the ferrule 3 includes a plurality of optical fiber alignment grooves 9 for aligning eight optical fibers in a central portion thereof, and optical connectors and light on both sides of the optical fiber alignment grooves 9. It includes a guide pin alignment groove 11 which is a reference of the alignment when the connector is connected. The upper plate 3a of the ferrule has the same structure that can be joined to face the lower plate 3b. And, between the optical fiber alignment groove 9 and the guide pin alignment groove 11 of the upper plate (3a) and the lower plate (3b), the alignment key 13 as a reference when coupling the upper plate (3a) and the lower plate (3b) ), The upper plate 3a and the lower plate 3b can be precisely coupled. As a result, the upper plate 3a and the lower plate 3b are combined to form one ferrule 3, and the guide pin alignment groove 11 is formed in one body with the optical fiber alignment groove 9, thereby reducing alignment errors. Minimize the connection.

3 to 6 are cross-sectional views showing various shapes of ferrules for multi-core optical connectors manufactured according to the present invention.

Specifically, the ferrule for the multi-core optical connector of FIG. 3 is a cross-sectional view of the upper and lower plates of the ferrule shown in FIG. 2, and the ferrule for the optical connector of FIGS. 4 to 6 is a top plate of various types of ferrules different from FIG. 3. And sectional drawing of the state which combined the lower board.

In more detail, the lower plate 21a of the ferrules of FIGS. 3, 5, and 6 has a plurality of optical fiber alignment grooves 23 for aligning optical fibers in a central portion thereof. Guide pin alignment grooves 25 are used at both sides to be coupled to the housing of the optical connector and serve as a reference for alignment when the optical connector and the optical connector are connected.

In particular, the optical fiber alignment groove 23 of FIG. 5 is configured in a V-shape, and the optical fiber alignment groove 23 of FIG. 6 is a semicircle and a V-shape. In addition, the guide pin alignment groove 25 of Figures 5 and 6 consists of a U-shaped narrow bottom. The upper plate 21b of the ferrule has the same structure as the lower plate 21a. In addition, the ferrule of FIG. 3 is aligned to facilitate coupling of the upper plate 21b and the lower plate 21a between the optical fiber alignment groove 23 and the guide pin alignment groove 25 in the upper plate 21b and the lower plate 21a. The key 27 is formed.

The lower plate 31a of the ferrule of FIG. 4 has a U-shaped recess 33 and other convex portions 35, and a plurality of optical fibers for aligning optical fibers in the central portion of the U-shaped recess 33 The alignment groove 37 is formed. And, the lower portion of the convex portion 35 is formed with a guide pin alignment groove 39 which is used to couple to the housing of the optical connector and serves as a reference for alignment when the optical connector and the optical connector are connected. The upper plate 31b of the ferrule is formed to have a structure that can be joined to the U-shaped concave portion facing the lower plate 31a. In addition, alignment keys 41 are formed at both sides of the optical fiber alignment groove 37 in the upper plate 31b and the lower plate 31a to facilitate coupling of the upper plate 31b and the lower plate 31a. As a result, the ferrule of FIG. 4 has a shape of a ferrule in which only the optical fiber alignment grooves 37 are separated into upper and lower plates without separating the guide pin alignment grooves 39. It is possible because it is easy to insert even if not separated.

Next, the manufacturing method of the ferrule for multicore optical connectors of this invention is demonstrated. First, a liga process (LIGA: LIGAthografie Galvanoformung Abformung) applied to the present invention will be described with reference to FIGS. 7A to 7D.

7A to 7D are views for explaining a method of forming a Riga mold by a Liga process applied to the present invention.

In general, the LIGA process is used to create three-dimensional microstructures, including deep-etch X-ray lithography, electroforming, and plastic molding. It is a micro machining technology consisting of three steps.

Specifically, a material film 53 made of a polymethylmethacrylate (PMMA) or a resin film capable of reacting with X-rays is formed on a plating base, for example, a substrate 51 on which Ti or Ti / Ni is formed or a metal substrate 51. do. Subsequently, the X-ray is irradiated to the material film using the X-ray mask 55 patterned to form the shape to be exposed. In the X-ray mask, the absorber portion in which the absorber is formed with respect to the X-rays does not transmit X-rays, and the X-rays transmit through the portion without the absorber to expose the material film (see FIG. 7A).

Next, a developing process using the difference in developing speeds between the portions irradiated with X-rays and the portions not irradiated to the exposed material film 53 is performed. In this way, patterns 57 are formed such that a portion of the substrate 51 is exposed (see FIG. 7B). Next, a metal film such as Ni or NiP is plated on the exposed substrate 51. In this case, a metal film 59 is plated on the exposed substrate 51 between the patterns 57 (see FIG. 7C). Subsequently, after the material film 53 is removed, the plating structure is separated from the substrate, thereby completing a single Riga mold 61 (see FIG. 7D).

Since the Riga mold by the Liga process is dependent on the shape of the X-ray mask, the error appearing during the Liga process is directly related to the error appearing during the manufacturing of the X-ray mask. Since the X-ray mask has an error in sub-micron units, when the Riga mold is manufactured using the X-ray mask, the size of the plating structure may be adjusted to about 0.1 μm. Therefore, the precision of 1 micrometer or less required by the ferrule for multi-core optical connectors can be easily realized. In addition, since the X-ray mask can be used repeatedly, ultra-precision Liga mold with a processing error of 0.1㎛ can be repeatedly produced and mass production.

8A to 8C are views illustrating an example of a ferrule manufacturing method for a multi-core optical connector of the present invention using a Liga process.

Specifically, a material film 73 capable of reacting with X-rays is formed on the substrate 71, for example, a substrate 71 made of silicon, glass, alumina, or metal. The material layer 73 is formed of polymethylmethacrylate (PMMA) or a resin layer. Subsequently, the material film 73 is irradiated with X-rays and exposed using an X-ray mask 75 patterned with an absorber having a ferrule form. In the X-ray mask, the absorber portion 77 in which the absorber is formed with respect to the X-rays does not transmit X-rays, and X-rays are transmitted through the non-absorber portion 79 without the absorber to expose the material film 73 ( See FIG. 8A). Next, a developing process using the difference in developing speed between the portion irradiated with the X-ray and the portion not irradiated to the exposed material film 73 is performed. In this case, the ferrule shape is realized so that a portion of the surface of the substrate is exposed. Subsequently, the material film 73 is removed and then separated from the substrate 71 to form a lower plate 81 of the ferrule (see FIGS. 8B and 8C).

Next, the steps of FIGS. 8A to 8C are repeated to form an upper plate (not shown) having the same structure as the lower plate 81. Subsequently, the lower plate 81 and the upper plate are combined to produce a ferrule for an optical connector. When the ferrule for the optical connector is manufactured in this way, the plating is not necessary during the above-described Liga process, and thus it is not necessary to form a plating base for plating on the substrate.

9A to 9F are views showing another example of a method for manufacturing a ferrule for a multi-core optical connector of the present invention using a Liga process.

Specifically, a material film 93 capable of reacting with X-rays is formed on a substrate 91 on which a plating (plating) base such as Ti or Ti / Ni is formed or on a metal substrate 91. Silicon, glass, or alumina is used as a material of the substrate 91 on which the plating base is formed. The material layer 93 is formed of polymethylmethacrylate (PMMA) or a resin layer. Subsequently, the material film 93 is exposed to light by irradiating the material film 93 using the X-ray mask 95 in which the opposite shape of the ferrule is patterned into the absorber. In the X-ray mask 95, the absorber portion 97 in which the absorber is formed with respect to the X-rays does not transmit X-rays and X-rays pass through the non-absorber portion 99 without the absorber to expose the material film 93. (See FIG. 9A).

Next, a developing process is performed in which the exposed material film 93 utilizes the difference in developing speed between the portion irradiated with the X-ray and the portion not irradiated. In this case, the exposed material film 93 is melted, and the opposite shape of the ferrule is implemented in the material film 93, and a portion of the substrate 91 is exposed (see FIG. 9B).

Next, a metal such as Ni or NiP is plated on the exposed substrate 91. In this case, the ferrule shape is implemented to form a plating structure 101 on the exposed substrate 91 (see FIG. 9C). Subsequently, since the surface of the formed plating structure 101 is rough and shows a thickness variation for each position, the surface of the plating structure 101 is polished in order to flatten and uniform the thickness (see FIG. 9D). Next, when the material layer 93 is removed and the plating structure 101 is separated from the substrate, the lower plate 103 of the ferrule for the optical connector is completed (see FIGS. 9E and 9F).

Next, the steps of FIGS. 9A to 9F are repeated to form an upper plate (not shown) having the same structure as the lower plate 103. Subsequently, the lower plate 101 and the upper plate are combined to manufacture a ferrule for an optical connector.

10A and 10B are views illustrating still another example of a ferrule manufacturing method for a multi-core optical connector of the present invention using a Riga process, and FIGS. 11A to 11E are cross-sectional views illustrating a Riga mold used in manufacturing the ferrule of FIG. 10B. admit.

First, the Riga mold 111 is prepared using a Riga process. The Riga mold 111 is manufactured by following the process of FIGS. 7A to 7D by patterning the opposite shape of the ferrule (the injection mold shape of the ferrule) on the X-ray mask, as shown in FIGS. 11A to 11E. Can be produced with Subsequently, the Liga mold 111 is assembled with a separate machining mold 113 manufactured by machining as shown in FIG. 10A, and plastic injection is performed using the ferrule. The machining mold by machining has a gate 115 for injecting the injection material and a mill pin for separating the injection molded product from the assembled mold. When plastic injection is performed, the lower plate 117 of the ferrule made of plastic is formed as shown in FIG. 10B. Subsequently, the steps of FIGS. 10A and 10B are repeated to form an upper plate (not shown) having the same structure as the lower plate. Subsequently, the lower plate and the upper plate are combined to produce a ferrule for an optical connector. The ferrule thus manufactured is shaped as shown in FIGS. 3 to 6.

In particular, in the Riga mold of the present invention, the side used for injection is not the top of the metal layer (plating layer) but the side. 7A to 7D, since the side surface of the metal layer is improved by plating along the wall of the developed material film, the roughness of the surface of the metal layer is several tens of nm or less corresponding to the surface roughness of the side surface of the developed material film. Considerably better than In addition, the use of the side has the advantage of being able to freely the desired shape. If the upper portion of the metal layer is to be used for injection, there is a disadvantage in that the shape of the grooves has to be perpendicular to the lithography process.

12A to 12D are views illustrating an example of a method of manufacturing a Riga mold used in manufacturing a ferrule for a multi-core optical connector of the present invention.

Specifically, the Riga mold shown in FIG. 10A illustrates a structure capable of injecting one ferrule, and the Riga mold shown in FIG. 12D illustrates a mold form for injecting several ferrules at one time.

In more detail, a method of manufacturing a Riga mold, a material film 123 capable of reacting with X-rays is formed on a substrate 121 or a metal substrate 121 on which a plating base such as Ti or Ti / Ni is formed. The material layer 123 is formed of polymethylmethacrylate (PMMA) or a resin layer. Subsequently, an X-ray is irradiated onto the material film 123 using an X-ray mask in which a ferrule is patterned into an absorber and exposed to light (see FIG. 12A).

Next, a developing process using a difference in developing speed between the portion irradiated with the X-ray and the portion not irradiated to the exposed material film 123 is performed. In this case, the exposed material film 123 melts to form a ferrule shape 125 formed of the material film 123 and expose a portion of the substrate 121 (see FIG. 12B).

Next, a metal such as Ni or NiP is plated on the exposed substrate 121. Subsequently, since the surface of the plated metal is rough and exhibits a thickness variation for each position, the surface of the metal is polished in order to flatten and uniform the thickness. Next, when the material layer 123 is removed, a metal structure 127 having a plurality of ferrule shapes is formed. Subsequently, the substrate surrounding the plating structure 127 is cut to form a li-metal mold composed of the substrate and the metal structure (see FIGS. 12C and 12D).

13A to 13D illustrate another example of a method of manufacturing a riga mold used in manufacturing a ferrule of the present invention.

Specifically, a material film 133 capable of reacting with X-rays is formed on a substrate 131 on which a plating base, such as Ti or Ti / Ni, is formed. The material layer 133 is formed of polymethylmethacrylate (PMMA) or a resin film. Subsequently, the material film 133 is irradiated with X-rays using an X-ray mask in which a ferrule is patterned into an absorber and exposed to light (see FIG. 13A).

Next, a developing process using the difference in developing speed between the portion irradiated with the X-ray and the portion not irradiated to the exposed material film 133 is performed. In this case, the exposed material layer 133 melts to form a ferrule shape 135 and expose a portion of the substrate 131 (see FIG. 13B).

Next, a metal such as Ni or NiP is plated on the exposed substrate 131. Subsequently, since the surface of the plated metal is rough and exhibits a thickness variation for each position, the surface of the metal is polished in order to flatten and uniform the thickness. Next, when the material layer 133 is removed, a metal structure 137 having a plurality of ferrule shapes is formed. Subsequently, the plating structure 127 is separated from the substrate to form a Riga mold made of the metal structure 137 (see FIGS. 13C and 13D).

As described above, the ferrule for the multi-core optical connector of the present invention is composed of a lower plate having an optical fiber alignment groove and a guide pin alignment groove and an upper plate corresponding thereto to easily insert an optical fiber. In addition, since the ferrule for the multi-core optical connector of the present invention is manufactured using a Liga process, a precision of 1 μm or less can be easily realized. Moreover, since the ferrule for multi-core optical connector of the present invention is manufactured by injection of a high precision liga into a mold, it is possible to replace ferrule production by conventional ceramic machining.

Claims (4)

Forming a material film capable of reacting with X-rays on the substrate; Exposing the material film using an X-ray mask having an opposite shape of a ferrule patterned into an absorber; Developing the exposed material film to expose the substrate to form a material film having a shape opposite to a ferrule therein; Filling a plating structure on the exposed substrate; Grinding and planarizing the plating structure; Removing the material layer to separate the plating structure to obtain a lower plate of the ferrule; Repeating the preceding steps to obtain a top of the ferrule; And The method of manufacturing a ferrule for a multi-core optical connector characterized in that it comprises the step of coupling the lower plate and the upper plate. The ferrule of claim 1, wherein the substrate is one selected from a silicon substrate having a plating base, a glass substrate having a plating base, an alumina substrate having a plating base, and a metal substrate. Manufacturing method. The method of manufacturing a ferrule for multi-core optical connectors according to claim 1, wherein the material film is formed of PMMA or a resin film. Forming a material film capable of reacting with X-rays on the substrate; Exposing the material film using an X-ray mask in which the shape of the ferrule is patterned into an absorber; Developing the exposed material film to implement the ferrule shape so that a portion of the surface of the substrate is exposed; Plating the exposed substrate to form a plating structure; Grinding and planarizing the plating structure; Removing the material film; Cutting the substrate to obtain a Riga mold made of a plating structure and a substrate, or separating the plating structure from the substrate to obtain a Riga mold; Preparing a machining mold capable of assembling and injecting the liga mold; Assembling the liga mold and the machining mold and then plastic injection to obtain a lower plate of the ferrule made of plastic; Repeating the preceding steps to obtain a top of the ferrule; And The method of manufacturing a ferrule for a multi-core optical connector characterized in that it comprises the step of coupling the lower plate and the upper plate.

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