JPS62267710A - Ferrule for optical connector - Google Patents

Abstract

PURPOSE:To easily fix an optical fiber to a ferrule in a short time, by previously filling up the narrow hole of the ferrule, into which the optical fiber is inserted, with solder. CONSTITUTION:A ferrule 1 is constituted of a capillary tube 2, terminal fittings 3 housed in one side of a hollow section 3a, and solder 4. The capillary tube 2 is formed of a ceramic material and driven into the terminal fittings 3 and its narrow-diameter hole having a diameter D is filled up with solder 4. The diameter D is made a little larger than that of an optical fiber 7 and the eccentricity of the narrow-diameter hole against the outer diameter A of the fittings 3 is set at or smaller than 1mum. After the ferrule 1 is kept by a heater composed of a V-groove 5 and keeping jig 6 and the solder 4 having a melting point of about 180 deg.C is melted by raising the temperature of the heater housed in the V-groove 5 to about 200 deg.C, the optical fiber 7 is inserted into the narrow hole of the capillary tube 7. After inserting the optical fiber 7, the ferrule 1 is removed from the heater. Thus the optical fiber 7 is fixed to the ferrule 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ferrule for an optical connector, and particularly to a ferrule that allows an optical fiber to be easily and quickly fixed to a connector on-site.

[Conventional technology]

Various optical connectors have been proposed and put into practical use in order to connect optical fibers with low loss and high reproducibility. For example, 1985 IEICE General National Conference &
In the convex spherical polished optical connector described in 2606, the optical fiber connection loss is 0.1 dB on average for multimode fiber.
1) An average of 0.26 dB was obtained with a single mode fiber), and the reproducibility during attachment and detachment was less than 0.1 dB for all fibers. Optical connectors with such characteristics are generally constructed by combining parts machined with high precision. The third of these
The ferrule 21 shown in the figure fixes and holds the optical fiber, and is one of the most important parts among the parts constituting the optical connector.

Conventionally, this type of ferrule consists of a capillary 22 having a small diameter hole 22a and an end member 23 that holds the capillary 22, as shown in FIG. was used, and the terminal member 23 was made of metal such as stainless steel.

FIG. 4 shows a state in which the optical fiber 24 is fixed to the capillary 22 of the 7-erule 21 shown in FIG. 3, and its tip has been polished.

7 Use adhesive 2 to fix the errule 21 and the optical fiber 24.
5 and solder were used.

[Problem that the invention seeks to solve]

The manufacturing of optical connectors as described above is often carried out not only in factories but also on-site, where optical cables are being installed.
Therefore, an optical connector with good on-site productivity is desired. However, there were the following drawbacks when fixing the fiber. When fixing optical fibers with adhesive, generally
The process involved stirring the adhesive, defoaming, and injecting the adhesive into the seven errules, and the workability was not necessarily good, as it required waiting until the adhesive hardened. On the other hand, when fixing an optical fiber to a ferrule with solder, the bonding process is recommended, as introduced in the paper "Characteristics of optical connectors with soldered fibers" presented at the 1985 IEICE General Conference Na2608. It has the advantage of being significantly shortened. However, this method required special equipment such as a solder bath and an ultrasonic generator, and was not necessarily an easy method to apply to on-site assembly of optical connectors.

[Means for solving problems]

The 7-ferrule of the optical connector of the present invention is located in a small diameter hole provided in the center of the cylindrical part of a ferrule for an optical connector made of ceramic, metal, a composite of ceramic and metal, or a composite of glass and metal. It has solder.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention.

A seventh errule 1 according to an embodiment of the present invention is composed of a capillary 2, a terminal fitting 3 in which the capillary 2 is housed on one side of a hollow portion 3a, and solder 4. The capillary 2 is made of ceramic and is driven into the terminal fitting 3. A small diameter hole extending over the capillary 20 is filled with solder 4. The diameter is set to be slightly larger than the outer diameter of the optical fiber inserted into the ferrule IK, and the eccentricity of the small diameter hole with respect to the outer diameter A of the terminal fitting 3 is suppressed to 1 μm or less.

FIG. 2 is a longitudinal cross-sectional view and a front view showing a state in which the optical fiber is fixed to the ferrule shown in FIG. 1. In the figure, 5.
6 shows a part of the heater, ■Groove 5 and holding jig 6
is holding down ferrule 1. A heater (
(not shown) is built-in, and the ferrule 1 is heated. In this example, the temperature setting of the heater was set at 200°C. Since we used solder 4 with a melting point of about 180°C, we used solder 4 that was heated to 200°C with a heater.
The solder 4 inside I/1 was completely melted. After the solder 4 is melted, the optical fiber 7 is inserted into the small diameter hole of the capillary 2,
Thereafter, the ferrule 1 is removed from the heater with the optical fiber 7 attached to the capillary 2, and the fixing of the ferrule 1 and the optical fiber 7 is completed.

The heater used was one that has been commonly used for curing adhesives. It goes without saying that the seven errules of the present invention cannot be applied to plastic items that are sensitive to heat.

〔Effect of the invention〕

As explained above, the present invention uses a ferrule in which the small diameter hole into which the optical fiber is inserted is filled with solder in advance, so that the optical fiber and the ferrule can be fixed in a shorter time and easier than before. There is an effect that it can be done. This method has advantages such as eliminating steps such as stirring the adhesive, defoaming, etc. in the conventional adhesive method, and does not require special jigs as in the conventional soldering method.

Therefore, if the optical connector ferrule of the present invention is used,
Optical connectors can be easily assembled on-site.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention, and FIG.
A vertical cross-sectional view and a front view showing an example of fixing an optical fiber to the ferrule shown in the figure, Fig. 3 is a longitudinal cross-sectional view showing an example of a conventional 7-ferrule, and Fig. 4 shows an optical fiber fixed to the ferrule shown in Fig. 3. FIG. 1... Ferrule, 2... Capillary, 3... Layer end fitting, 4... Early release, 5...
・・・■Groove of heater, 6... Holding jig, 7... Optical fiber, 21... Example of conventional 7 errule, 22... ...Capillary, 22
a...Small diameter hole, 23...Terminal member, 2
4...Optical fiber, 25...Adhesive. To 7th page - 1''' - ゛ Agent Patent attorney Uchihara Kame, - Engineering $ I L song (1 87th flash No. 4

Claims (1)

[Claims] In a cylindrical optical connector ferrule made of ceramic, metal, a composite of ceramic and metal, or a composite of glass and metal, solder is applied to a small diameter hole provided on the central axis of the cylindrical portion of the ferrule. An optical connector ferrule characterized by being filled with.