JPS62136612A - Soldering method for optical connector - Google Patents

Abstract

PURPOSE:To prevent a defect in soldering from occurring owing to the generation of gas by leaving a solder space between the coating tip part of an optical fiber and the bottom part of an insertion hole as the entrance part of an optical fiber insertion hole and inserting solder so that the both do not contact each other. CONSTITUTION:A cord holder 14 is lowered to insert the resin coating 2 of an optical cord and the trip part of an optical fiber 3 into the cord insertion hole 4 and fiber insertion hole 5 in a ferrule 1 which contains molten solder 7 so that the resin coating 2 of the optical cord and the tip part of the fiber 2 are fitted in both holes. At this time, the projection end of the optical fiber 3 is cleaned with ozone and then impurities sticking on its peripheral surface are removed, so that soldering is performed excellently. The insertion depth of the optical cord is so set that the tip of the resin coating 2 stops while the solder space 11 is left at the bottom part of the cord insertion hole 4, and the tip of the optical fiber 3 projects from the tip of the ferrule 1 at the time of the stop. Heating by a heater 9 is removed while the insertion of the optical cord is stopped, and the soldering is completed. Thus, a defect in soldering is prevented from occurring owing to the production of gas.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of soldering optical connectors used as wiring for optical communications and other information transmission.

<Prior art> A conventional method of fixing an optical connector and an optical fiber by soldering is, for example, as shown in Japanese Patent Laid-Open No. 59-129816, in which the optical fiber is inserted into a sleeve-shaped optical connector, and the optical fiber and the optical fiber are connected inside the optical connector. A method of fixing the periphery by soldering is known.

Alternatively, as an improvement to the above method, a resin-coated optical cord is inserted inside a sleeve-shaped optical connector, and the optical fiber is inserted into the fiber insertion hole at the tip of the optical connector.
A method has been proposed in which the optical fiber is soldered to the inner peripheral surface of the fiber insertion hole.

<Problems to be Solved by the Invention> In all of the above methods, molten solder is interposed between the optical fiber and the inner circumferential surface of the optical connector to solder and fix the two. When a cord is inserted and the resin coating of the optical cord comes into contact with the heated connector under sealed conditions, the resin coating melts or burns and generates gas inside the connector, and this gas flows between the optical fiber and the fiber insertion hole. Since it ejects from the tip through the gap, it has the disadvantage of causing poor soldering between the optical fiber and the optical connector.

Means for Solving the Problems> The method of the present invention for solving the above problems includes having a cord insertion hole in the sleeve-like main body, and forming a micro-diameter fiber insertion hole at the tip of the cord insertion hole. Insert a resin-coated optical fiber with a protruding tip into the ferrule.
In the method of soldering an optical fiber to the inside of a ferrule, a certain distance is placed between the coated tip of the optical fiber and the bottom of the cord insertion hole, which is the entrance of the optical fiber insertion hole, so that they do not come into contact when inserting the optical fiber into the ferrule. The ferrule is inserted leaving a solder space, and the molten solder is introduced into the ferrule to a depth that substantially fills the solder space.

Effects> In the method of the present invention, the amount and time of contact between the heated inside of the connector and the resin coating of the optical cord are small, so the generation of gas inside the connector due to melting or combustion of the resin due to such contact is prevented. Ru.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional view of an optical connector soldered by the method of the present invention, in which a ferrule 1 has an optical fiber 3 with a resin coating 2. It has a sleeve-like shape, with a cord insertion hole 4 to be inserted therethrough, and a fiber insertion hole 5, which is a microhole into which the tip of the optical fiber 3 is inserted, at the lower part thereof. A small-diameter fiber insertion hole 5 is provided at the lower end of the ferrule 1 and forms the lower end of the cord insertion hole 4, and the entrance portion 6 is formed into a forest-like recess so as to guide the insertion of the optical fiber into the center. There is.

For example, as shown in FIG. 2, the tip of the ferrule 1 is held by a holder 12 in a solder holding section 8 where molten solder 7 is jetted from the tip or the molten solder is simply held while applying ultrasonic vibration. The fibers are pressed into contact with each other, and the molten solder 7 is introduced from the open end of the fiber insertion hole 5. At this time, since the lower part of the ferrule 1 is appropriately heated by the heater 9, the molten solder 7 is gradually stored at the bottom of the cord insertion hole 4.

On the other hand, the tip of a resin-coated rod-shaped sensor electrode 10 is inserted into the solder introduction amount setting position in the cord insertion hole 4 and is waiting at a predetermined position, and the liquid level of the molten solder 7 rises and the sensor When it comes into contact with the electrode 10, a current flows through the sensor electrode, the ultrasonic vibration is stopped, and the introduction of molten solder is stopped, and a pilot lamp or other alarm (not shown) to notify this is activated. ing. After stopping the solder introduction, the sensor electrode is removed and preliminary soldering is completed inside the ferrule.

The position of the tip of the sensor electrode 10 is adjusted and set by a stopper 13 or the like so that it substantially coincides with the position where the tip of the resin coating 2 of the optical cord stops, and the tip of the resin coating 2 does not touch the entrance portion 6 of the fiber insertion hole 5. The insertion is stopped so as to leave a predetermined solder space 11 between it and the inlet 6. As a result, the molten solder 7 is introduced and held in the solder space 11 so as to be filled therein.

FIG. 3 shows the state in which the optical fiber 3 is soldered to the ferrule 1. The resin coating 2 of the optical cord and the tip of the fiber 3 are inserted into the cord insertion hole 4 and the fiber insertion hole 5 in the ferrule 1, which contains the molten solder 7. The cord holder 14 is sequentially inserted while being lowered so that the parts are fitted together. At this time, if the protruding end of the optical fiber 3 is previously cleaned with ozone using an ozone generator or the like, impurities adhering to the peripheral surface of the optical fiber 3 will be removed, and the hunter's injury will be better performed.

As already mentioned, the insertion depth of the optical cord is such that the tip of the resin coating 2 is at the bottom of the cord insertion hole 4 in the solder space 11.
The optical fiber 3 is set so as to stop with the ferrule 1 remaining, and when the optical fiber 3 stops, the tip of the optical fiber 3 protrudes from the tip of the ferrule 1.

As described above, the soldering is completed by canceling the heating by the heater 9 or cooling by heat radiation while the insertion of the optical cord is stopped.

In the above embodiment, the case where preliminary soldering and optical fiber soldering are performed consecutively has been explained, but when the solder inside the ferrule is solidified after the preliminary soldering is completed, the preliminary soldered connector as shown in Fig. 4 is formed. It becomes possible. This connector with solder 7' requires complicated equipment such as an ultrasonic vibrator in order to heat the end of the ferrule, melt the solder inside, and insert the optical fiber 3 into it in the manner described above. This provides the advantage that soldering can be easily carried out on-site, regardless of location and time.

<Effects of the Invention> As a result of the present invention being constructed as described above, there are problems such as when the optical connector is soldered and fixed, a large amount of the resin coating of the optical cord melts, resulting in poor soldering due to internal gas generation, etc. This provides the advantage of providing an extremely reliable optical connector.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a cross-sectional view of an optical connector soldered by the method of the present invention, FIGS. 2-3 are cross-sectional views also showing the soldering process, and FIG. is a cross-sectional view of a pre-soldered optical connector. 1: Ferrule 2: Covering 3: Optical fiber 4: Cord insertion hole 5: Optical fiber 6; Inlet section 7; Melted solder 9; Heater 11; Solder space

Claims (1)

[Claims] 1) Insert a resin-coated optical fiber with a protruding tip into a ferrule that has a cord insertion hole in the sleeve-like body and a micro-diameter fiber insertion hole at the tip of the cord insertion hole, and then insert the resin-coated optical fiber into the ferrule. In the method of soldering the inside of the optical fiber to the ferrule, when inserting the optical fiber into the ferrule, a certain distance is placed between the coated tip of the optical fiber and the bottom of the cord insertion hole, which is the entrance of the optical fiber insertion hole, to prevent them from coming into contact with each other. A method for soldering an optical connector, characterized in that the solder is inserted leaving a solder space consisting of an empty space, and the molten solder is introduced into the ferrule to a depth that substantially fills the solder space.