JP2003201590A - Multi-core ferrule manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the fraction defective by clearing the very stringent accuracy of the hole diameter and the position, to improve the productivity, and to reduce the total production cost in a multi-core ferrule manufacturing method in which a plurality of metal wires, etc., are used for master, the wires are removed after the electro-casting and ferrule is machined. <P>SOLUTION: A part in the vicinity of a center part 19 of an electro-cast part 18 is cut, and a tip surface 20 of a part in the vicinity of and in contact with an electric insulating sheet 9 capable of obtaining the dimensional accuracy is used for a tip part of the completed ferrule. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multi-fiber ferrule used for optical fiber connectors and devices.

[0002]

2. Description of the Related Art Conventionally, a multi-core ferrule used for optical fiber connectors, devices, etc. has two guide holes 2 and a very thin hole 3 of about 0.125 mmφ as shown in the side view of FIG. The multi-core ferrule 1 is formed in a shape with a depth of about 8 mm, which is opened in a plurality of accurate positions, and the material is mainly made of plastic.

The multi-core ferrule made of plastic as shown in FIG. 1 is manufactured by injection molding. However, there is a problem of insufficient dimensional accuracy due to bending or breaking of the core pin, or a fatal defect such as clogging of a hole. It often occurs, and it is often necessary to polish the end face, but because the difference in hardness between the plastic ferrule and the silicon optical fiber is very large, it is difficult to polish the end face. was there.

On the other hand, the present inventor has filed a patent application No. 2001-109.
No. 269 proposes a multi-core ferrule made of metal, which is made of metal such as nickel by electroforming, using a metal or plastic wire as a mother die.

In the patent, FIG. 2 and FIG.
An electrically insulating thin plate 9 such as a glass thin plate or a ceramic thin plate in which a planar shape as shown in FIG. 3 is punched at an accurate position by a wet etching method in a photoresist method is used as a component of the cathode jig 8 and a wire is provided in the hole. Or a method of inserting a wire material having good dimensional accuracy in the V groove by using an electrically insulating plate such as a glass plate or a ceramic plate having a V groove at an accurate position as a component of the cathode jig 8. 2 is an example of a two-core type cathode jig. The upper plate 10 and the lower plate 11 are shown in FIG.
Are fixed by four or three columns 12, and the upper plate 10 and the lower plate 11 are made of an electrically insulating material such as polyvinyl chloride resin, polyamide resin, polyacetal resin, or polyethylene resin. Is made of metal such as stainless steel or titanium, or plastic. The upper plate 10, the lower plate 11, and the columns 12 are fixed with screws, and the right and left 2 of the upper plate 10 are fixed.
A stainless steel spring 6 is fixed to the place with a stainless screw or the like. The lower plate 11 has two parts on the left and right of the upper plate 10 and the target position.
Plastic clips 13 are screwed to the places, and circular holes 14 for air nozzles are drilled at four places. First, the stainless steel wire 5 is passed through the holes of the electrically insulating thin plate 9 having two cores made by the photoresist method, and then the electrically insulating thin plate 9 made of stainless steel has a hole at the center thereof. The electrically insulating thin plate 9 is fitted in the recess 17 having the same shape as the elastic thin plate 9, fixed to the hooking portion 15 of the spring 6 made of stainless steel, and the wire 5 is stretched to stretch the spring 6 and sandwich it with the clip 13 to pull it. Then, the two wire rods 5 may be electroformed by paralleling and straightening. In FIG. 2, seven electrically insulating thin plates 9 are used, but the number of electrically insulating thin plates 9 can be arbitrarily selected depending on the electroforming interval, electroforming length, etc. The number of pieces is also within the scope of the present invention, and by arranging the electrically insulating thin plate 9 at an interval slightly longer than the length of one multi-core ferrule, it is possible to reliably prevent the movement of the plurality of wire rods 5. Accordingly, the portion of the wire 5 that is extremely close to the portion fixed by the electrically insulating thin plate 9 becomes the contact portion between the completed ferrules, so that the hole position accuracy can be further improved.

In this patent, the electrically insulating thin plates 9 are provided at intervals slightly longer than the length of one multi-core ferrule.
A method of manufacturing a multi-core ferrule with a hole diameter and hole position that requires sub-micron accuracy has been proposed by adopting a configuration in which the dimensional accuracy is improved. Since it is a separate production, there is a problem in productivity, and the method of making holes at accurate positions by the wet etching method in the photoresist method is adopted, but sometimes the dimensional accuracy is insufficient. .

[0007]

In view of the above, the present invention has been made.
In a method for manufacturing a multi-core ferrule, in which two or more wires 5 such as metal are used for a mother die, and after electroforming, the wires are removed and then machined, the conventional method is improved to improve the hole diameter and position. The objectives are to further reduce the defect rate by clearing extremely strict accuracy, improve productivity, and further reduce the overall production cost.

[0008]

In order to solve the above-mentioned problems, according to the present invention, as shown in FIG. 2, a hole is formed at an accurate position by a dry etching method in a photoresist method, an electric discharge machining, and a special drilling in an NC machining. An electrically insulating thin plate 9 such as an opened glass thin plate, ceramic thin plate, plastic thin plate, etc. is set on the cathode jig 8 and a wire is passed through the hole, and electricity is provided at intervals slightly longer than the length of one multi-core ferrule. A method of electroforming by arranging the insulating thin plate 9, a method of fixing the position of the columnar body by a method of sandwiching it with a plate having an electrically insulating V groove such as ceramic or plastic, and a method of fixing the position of the cylinder as shown in FIG. Cut near the center portion 19 of the electroformed portion 18 at intervals, and use the tip surface 20 near the contact with the electrically insulating thin plate 9 that is easy to obtain dimensional accuracy for the tip portion of the completed ferrule. A means of adopting.

[0009]

4 (a) and 4 (b) show one embodiment of the electrically insulating thin plate 9 of the present invention. FIG. 4 (a) is a four-core type, and FIG. It is a core type and has two position guide holes 2 at the left and right ends and holes 1 aligned in an exact position, and the thickness is 0.05 to 0.8.
In the case of a multi-core ferrule manufactured by using an electrically insulating thin plate 9 as shown in FIG. 4, it is necessary to use a thick wire to open the position guide hole 2, In this case, it is appropriate to describe not a wire but a thin rod, but in the present invention, all are expressed as a wire rod 5, and thus the wire rod 5 has a thickness of 0.02 mm to
It is a cylindrical line having a round cross section of about 3.0 mmφ.

FIG. 2 shows an embodiment of a two-core type cathode jig according to the present invention.
The upper plate 10 and the lower plate 11 are fixed by a column 12. The upper plate 10 and the lower plate 11 are made of an electrically insulating material such as polyvinyl chloride resin, polyamide resin, polyacetal resin, or polyethylene resin, and the column 12 is made of stainless steel or titanium. Use metal or plastic such as. The upper plate 10, the lower plate 11 and the columns 12 are fixed with screws, and the springs 6 made of stainless steel are fixed to the left and right two places of the upper plate 10 with stainless screws or the like. The lower plate 11 has a structure in which upper plate 10 and plastic clips 13 are fixed at two positions on the left and right of the target position, and circular holes 14 for air nozzles are drilled at four positions. There is. First, the stainless steel wire 5 is passed through the holes of the electrically insulating thin plate 9 having two holes made by the photoresist method, and then the electrical insulation having the hole at the center of the supporting plate 16 made of a stainless thin plate or the like. The electrically insulating thin plate 9 is fitted in the recess 17 having the same shape as the elastic thin plate 9, fixed to the hooking portion 15 of the spring 6 made of stainless steel, and the wire 5 is stretched to stretch the spring 6 and sandwich it with the clip 13 to pull it. Then, the two wire rods 5 may be electroformed by paralleling and straightening. In FIG. 3, seven electrically insulating thin plates 9 are used, but the number of electrically insulating thin plates 9 can be arbitrarily selected depending on the electroforming interval, electroforming length, etc. Individuals are also within the scope of the invention.

In the method of making holes in the electrically insulating thin plate 9 of the present invention, when the etching method of the photoresist method is adopted, for example, JP-A-11-17091 is used.
It is possible to use the technology that applies the technology for manufacturing integrated circuits, which has been filed for a number of applications, such as coating a photoresist film on a thin plate such as glass, forming accurate positions and hole diameters by printing, etc., and drying, then exposing A light beam such as a laser beam is irradiated through a pattern mask to form an exposed portion. Exposing portions of the photoresist causes a chemical change in the photoresist that can be developed by other chemical treatments. For example, leaving the unexposed part soluble and making the exposed part insoluble,
Or it can be made non-reactive with a particular developer,
Conversely, depending on the photoresist, the exposed areas can be made soluble in the selected developer. Therefore,
Here, one of two manufacturing methods can be adopted depending on whether the photoresist is a “positive” or “negative” photoresist. For example, a solvent for dissolving the exposed portion of the photoresist film is used. Then, by exposing the electrically insulating thin plate such as glass or silicon by removing the exposed portion by spraying or the like, a hole is formed by a wet etching method using a corrosive liquid such as a fluoride aqueous solution, or a dry etching method is generally used. A method of making holes by irradiating the so-called high-density plasma can be adopted, and for example, a method of using helicon plasma that generates high-density plasma by inductive coupling between RF and a magnetic field is effective in obtaining a uniform ion current density in a large area. It is desirable because it can be obtained, and processing with high accuracy and high productivity becomes possible.

Further, for example, by using an NC machine tool using a stage such as a linear motor, a guide hole is first made at an accurate position by laser processing, and then diamond particles or the like are applied to the surface of the super hard material for finishing. It is possible to use a method of using an electrically insulating thin plate such as glass or silicon in which a highly precise hole has been drilled with a special drill, or the wire 5 is sandwiched between commercially available V-groove substrates such as glass, silicon or plastic. The method of fixing with may be adopted.

The present inventor has also filed a patent application 2001-21.
It is also possible to use a conductive ceramic thin plate filed in No. 7340 for positioning by using a porous plate formed by electric discharge machining, for example, for non-oxide type, carbide type, nitride type, etc. It is possible as long as it is slightly conductive at room temperature, and some of the ternary oxides are also conductive and can be used. Zirconium bromide, titanium boride, sialon, N-type single crystal silicon by CZ method, etc. are suitable, and a method of opening pores by electric discharge machining is adopted, but electric discharge machining utilizes the phenomenon of electrode consumption due to electric discharge. Since it is a non-contact processing that does not directly touch the work piece, it is suitable for extremely fine processing.The principle is that the electrode corresponding to the tool and the work piece are opposed to each other while maintaining a certain distance. ,That In this state, a pulsed discharge current with a large number of cycles (several tens to several hundreds of thousands / second) is generated to process metal while melting it, and fine holes are processed while rotating a thin electrode at high speed. A fine electric discharge machine and a wire electric discharge machine (W.EDM) that processes a two-dimensional contour in a sawtooth shape while winding a wire electrode, and a thin electrode is formed to a diameter of several μm by a wire electric discharge grinding method. However, a method of performing fine holes or three-dimensional processing by arbitrarily moving the electrode is suitable.

FIG. 5A is a plan view showing a state in which the wire 5 is positioned by being sandwiched in the V groove 23 of the present invention.
Although (b) is a side view, the V groove may be a plastic molded product or a ceramic plate such as silicon manufactured by polishing.

The electroforming apparatus is, for example, as schematically shown in FIG. 6, in which the electroforming liquid 18, the plus electrode 19, the cathode jig 8, the air stirring nozzle 21, the spring 6, the minus electrode 20, the wire rod 5,
The electroforming liquid 18 is composed of an electrically insulating thin plate 9, and the electroforming liquid 18 is different in the material of the intended electroformed metal, but is, for example, nickel or its alloy, iron or its alloy, copper or its alloy, cobalt or its. Electroformed metals such as alloys, tungsten alloys and fine particle dispersed metals can be adopted, nickel sulfamate, nickel chloride, nickel sulfate, ferrous sulfamate, ferrous borofluoride, pyrophosphoric acid shell, copper sulfate, borofluoride An aqueous solution whose main component is an aqueous solution of copper, copper silicofluoride, copper titanium fluoride, alkanol copper sulfonate, cobalt sulfate, sodium tungstate, or the like is used. Of these, a bath containing nickel sulfamate as a main component is particularly suitable in terms of easiness of electroforming, variety of physical properties such as hardness, chemical stability, and ease of welding. The electroforming liquid may be filtered at high speed with a filter having a filtration accuracy of about 0.1 to 5 μm, and may be heated to control the temperature within an appropriate temperature range of about ± 3 ° C.

The positive electrode 19 differs depending on the intended electroformed metal, and is selected from nickel, iron, copper, cobalt, etc., and a plate-shaped or spherical electrode is appropriately used. If you use a spherical one, put it in a titanium basket,
It may be used by covering with a polyester cloth bag. Then, four positive electrodes 19 are arranged around the wire 5 and a small amount of air is blown out from the hole of the air stirring nozzle 21 to carry out stirring. However, this agitation is not limited to air agitation, and other agitation such as propeller, ultrasonic wave, and super vibration can be adopted.

The wire 5 is a metal wire such as iron or its alloy, aluminum or its alloy, copper or its alloy, a thin solder plating on this metal wire or thin rod, and a plastic such as nylon or polyester. A wire or a thin rod is appropriately selected and used. Among them, in the case of plastic, nickel, to impart conductivity to the surface,
Electroless plating of silver or the like is required, and the wire rod 5 is required to have high accuracy in thickness, roundness, and linearity, and is manufactured by a method such as extrusion by a die, wire drawing, and centerless processing.

The electroforming will be carried out by the above-mentioned apparatus. The electroforming is carried out by applying a direct current at a current density of about 3 to 8 A / dm ² and growing it to a predetermined size. It is taken out from the electroforming tank, washed well with water, and then dried, but the interval between the cathode jig 8 and the plus electrode 19 described in Japanese Patent Application No. 2000-104113 previously filed by the present inventor is the same. It is desirable to adopt a method of electroforming while rotating the wire rod 5 around the center because the uneven thickness and bending can be prevented.

In the present invention, an electrically insulating thin plate 9 such as a glass thin plate or a ceramic thin plate in which holes are formed at precise positions.
Is set in the cathode jig 8 and the wire 5 is passed through the hole, and the electrically insulating thin plates 9 are arranged at intervals slightly longer than the length of one multi-core ferrule to electroform one ferrule. By adopting the method for manufacturing, it is possible to manufacture a multi-core ferrule with extremely good dimensional accuracy.

Further, as shown in FIG. 3, the tip of the ferrule is completed by cutting near the center portion 19 of the electroformed portion 18 to form the tip surface 20 near the electrically insulating thin plate 9 having the highest dimensional accuracy. The method used for the section may be adopted, and FIG.
Is an example thereof, but at the tip of the ferrule body 24,
The end surface 20 of the electroformed part 18 is used as a surface for press-fitting. In this case, the electrically insulating thin plate 9 is processed by making the interval thereof appropriately longer than the length of one multi-core ferrule. It does not matter even if a means for facilitating is adopted, and by adopting this method, when the interval is about the length of the multi-fiber ferrule for one piece, only one piece can be produced, but two pieces can be produced. Therefore, the productivity can be doubled, and the interval between the electrically insulating thin plates 9 can be made rough in electroforming, so that the wire rod 5 can be easily set on the electroforming jig.

[0021]

EFFECT OF THE INVENTION The present invention is a method for producing a multi-core ferrule in which two or more wire rods 5 made of metal or the like are used as a mother die by the method described above, and the columnar body is removed after electroforming. In order to position the wire 5 of the cathode jig, the dry etching method in the photoresist method or N by the special drill is used.
By adopting the electrically insulating thin plate 9 manufactured by C machining and electric discharge machining, the accuracy required for the mother die of the cathode jig is cleared, and the interval is slightly longer than the length of just one multi-core ferrule. By adopting the configuration in which the electrically insulating thin plate 9 and the like are arranged, the dimensional accuracy is further improved, and as shown in FIG. 3, it is easy to obtain the dimensional accuracy by cutting near the central portion 19 of the electroformed portion 18. By adopting a means for using the tip surface 20 near the electrically insulating thin plate 9 at the tip of the completed ferrule, dimensional accuracy and productivity can be significantly improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view and a side view of a multicore ferrule for an optical fiber according to a conventional method.

FIG. 2 is a side view showing an embodiment of a two-core type cathode jig according to the present invention.

FIG. 3 is a cross-sectional view of the electroformed part 18 according to the present invention, which is cut near the central part 19 and has a tip surface 20 near the electrical insulating thin plate 9 or the like, which is easy to obtain dimensional accuracy, to be used for the tip portion of a completed ferrule. It is a sectional side view for explanation of a means.

FIG. 4 is a plan view showing an example of the shape of the electrically insulating thin plate 9 in the case of manufacturing the multi-core type ferrule according to the present invention.

5A and 5B are a plan view and a side view showing a state in which a wire 5 is sandwiched and fixed in a V groove according to the present invention.

FIG. 6 is a schematic configuration diagram showing an embodiment of an electroforming manufacturing apparatus according to the present invention.

FIG. 7 is a side cross-sectional view showing a state in which the front end surface 20 of the electroformed portion 18 is used as the front surface and press-fitted into the front end of the ferrule body 24 according to the present invention.

[Explanation of symbols]

1 Ferrule 2 True Circular Hole 3 Wire Holding Member 4 Hole 5 Wire Material 6 Spring 8 Cathode Jig 9 Electrically Insulating Thin Plate 10 Upper Plate 11 Lower Plate 12 Post 13 Clip 14 Circular Hole 15 Hooking Part 16 Support Plate 17 Wire Positioning Clip 18 Electroforming Liquid 19 Positive Electrode 20 Minus Electrode 21 Air Stirring Nozzle 22 Position Guide Hole 23 V Groove 24 Ferrule Main Body

Claims (7)

[Claims] 1. A method for producing a multi-core ferrule, which comprises using, as a mother mold, two or more wire rods 5 made of metal, plastic, or the like stretched, and then electroforming the wire rods 5. For positioning the wire 5 of the cathode jig for electroforming, a plurality of electrically insulating thin plates 9 each having a hole formed at a predetermined position by the dry etching method in the photoresist method are arranged in a straight line, A method for producing a multi-core ferrule, characterized in that the wire 5 is passed through the holes of the electrically insulating thin plate 9 and electroformed. 2. A method for positioning a wire rod 5 of a cathode jig for electroforming,
2. The electroforming according to claim 1, wherein a plurality of electrically insulating thin plates 9 having a perforated hole formed by NC processing using a special drill coated with diamond particles or the like on the surface of a superhard material are used for electroforming. Manufacturing method of heart ferrule. 3. Positioning of the wire rod 5 of a cathode jig for electroforming,
The method for producing a multi-core ferrule according to claim 1, wherein a plurality of electrically insulating thin plates 9 having a plurality of holes formed by electric discharge machining are used for electroforming. 4. The method for producing a multi-fiber ferrule for an optical fiber according to claim 1, wherein the electrically insulating thin plates 9 are arranged at intervals slightly longer than the length of one multi-fiber ferrule. . 5. A method for producing a multi-core ferrule in which two or more wire rods 5 made of metal, plastic, etc. are used as a mother die, and the wire rods 5 are electroformed and then removed. Then, the electrically insulating thin plate 9 in which the hole positions are arranged in a straight line
For an optical fiber, characterized in that it is cut at a position near the middle 19 of the electroformed part 18 between and the tip surface 20 near the contact with the electrically insulating thin plate 9 is used for the tip part of the completed ferrule. Manufacturing method of multi-core ferrule. 6. Instead of the electrically insulating thin plate 9, an electrically insulating plate such as a plurality of plastics having accurate V-grooves is used as a component of the cathode jig 8, and the wire 5 is placed in the V-groove. The method for producing a multi-core ferrule according to claim 5, wherein a method of deciding the position of the wire rod 5 between them is adopted. 7. The electrode material of the cathode jig 8 is electroformed while the wire material 5 of the cathode jig 8 is rotated substantially at the center so that the distance between the wire material 5 of the cathode jig 8 and the anode is substantially the same. 1. A method for manufacturing a multi-fiber ferrule for optical fiber according to any one of 1 to 6.