JPS62227107A - Assembling method for optical connector - Google Patents

Abstract

PURPOSE:To eliminate the damage of an optical fiber, to prevent it from deteriorating in strength, and to improve the reliability of an optical connector by applying ultrasonic vibrations to the axial hole of a ferrule in a heated state and charging fused solder, and ceasing the ultrasonic vibrations and then inserting and soldering an optical fiber in the axial hole of the ferrule by soldering. CONSTITUTION:An ultrasonic wave chip 1 is made to abut on the front end surface of the ferrule 5 and while ultrasonic vibrations are applied, the fused solder 8 is charged in the axial hole 9 of the ferrule 5 and the center hole 10 of a ferrule support 6. The ultrasonic-wave chip 1 is separated from the ferrule 5 and then the optical fiber after part of the optical fiber jacket part 12 of the optical fiber core 11 is removed is inserted into the axial hole 9 of the ferrule 5, i.e. solder 8 fused by being heated by a heater 7, thereby soldering the optical fiber 13 to the axial hole 9 of the ferrule 5. At this time, the optical fiber jacket 12 in the center hole 10 of the ferrule support 6 is covered with solder 8. Then, the ferrule support 6 and optical fiber core 11 are fixed by a heat-shrinkable tube 14.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an improvement in an assembly method for fixing an optical fiber and a ferrule, which are components of an optical connector.

(Prior art) Optical connectors generally consist of a pair of optical fibers, in which a coated part of an optical fiber is inserted and fixed into the center hole of a ferrule support into which a ferrule is press-fitted, and an optical fiber is inserted and fixed into the axial center hole of the ferrule. The end face of the ferrule is configured to abut within the through hole of the housing for optical coupling. At this time, it is a matter of course that the optical fiber needs to be securely fixed to the axial center hole of the ferrule. Organic adhesives (hereinafter referred to as bone cements) are mainly used to fix optical fibers and ferrules, but since adhesives take a long time to harden, assembly time is long. A known method is to fix with solder.

Conventionally, in order to fix an optical fiber and a ferrule with solder, as shown in FIG.
After inserting the ferrule 5 into the axial center hole 9 of the ferrule 5, the tip portion of the ferrule 5 is immersed in the solder bath 20 of the ultrasonic soldering device filled with solder for bonding glass and ceramics. This device is equipped with an ultrasonic transducer 22 at the bottom of a solder bath 20 that heats solder 8 with a heater 21 and holds it in a melted state. Vibrations are transmitted. Next, ultrasonic vibration is applied to remove foreign matter in the minute gap between the axial center hole 9 of the ferrule 5 and the optical fiber 13, and the solder 8 is raised into the minute gap by capillary action, and the optical fiber 13 and the ferrule 5 are The shaft center hole 9 is fixed with solder.

(Problems to be Solved by the Invention) In the method described above, when ultrasonic vibration is applied, the optical fiber repeatedly collides with the axial center hole of the ferrule, so that a minute 1u may be attached to the surface of the optical fiber. This has the disadvantage that the breaking strength of the optical fiber deteriorates.

(Objective of the Invention) The present invention aims to improve the reliability of an optical connector by preventing deterioration of the strength of the optical fiber due to ultrasonic vibration in an assembly method in which an optical fiber is inserted into an axial hole of a ferrule and fixed by soldering. be.

(Means for Solving the Problems) In order to eliminate the drawbacks of (e) above, the present invention heats the axial center hole of the ferrule with a heater, and melts the ferrule while applying ultrasonic vibration to the heated axial center hole. After that, the ultrasonic vibration is stopped, an optical fiber is inserted into the axial hole, and the axial hole of the fleur and the optical fiber are fixed with solder.

(Function) According to the present invention, molten solder is filled while applying ultrasonic vibration to the heated shaft center hole, and then the ultrasonic vibration is stopped and the optical fiber is inserted into the shaft center hole. , the optical fiber will not repeatedly collide with the center hole of the ferrule.

(Example) The assembly method of the present invention will be explained below with reference to the drawings.

2 to 4 show an embodiment of the present invention,
Portions similar to those of the conventional example are represented by the same reference numerals. In the figure, reference numeral 1 denotes an ultrasonic chip, a heating heater 2 is wound around the ultrasonic chip 1, and an ultrasonic vibrator 4 is connected to the rear end via a horn 3. A ferrule 5 made of ceramic is press-fitted into a counterbore hole provided in a ferrule support 6 made of metal and integrated.

The ferrule 5 is sandwiched and heated by a preheating heater 7, and a solder 8 for bonding glass and ceramic is attached to the tip surface of the ultrasonic chip 1 heated by a heating heater 2 and melted. The ultrasonic tip 1 is brought into contact with the tip surface of the ferrule 5, and while applying ultrasonic vibration, the molten solder 8 is passed through the axial hole 9 of the ferrule 5 and the center hole 10 of the ferrule support 6.
(See Figure 3).

As shown in FIGS. 2 and 3, after separating the ultrasonic chip 1 from the ferrule 5, the optical fiber 13 from which a portion of the optical fiber coating 12 of the optical fiber core 11 has been removed is inserted into the axial center hole of the ferrule 5. That is, it is inserted into the solder 8 which is in a molten state by the heating of the heater 7, and the solder 8 causes
The optical fiber 13 and the axial hole 9 of the ferrule 5 are fixed with solder.

At this time, the optical fiber coating 12 in the center hole 10 of the ferrule support 6 is covered with the solder 8. After that, the ferrule support 6 and the optical fiber core wire 11 are connected to each other using the heat shrink tube 14.
are fixed, and the tip end surface of the ferrule 5 is polished so that the end surface of the optical fiber 13 becomes a mirror surface.

With such an assembly method, the optical fiber 13 is firmly fixed to the axial hole 9 of the ferrule 5 with the solder 8. Further, the axial hole 9 of the ferrule 5 is filled with melted solder 8 in advance, and no ultrasonic vibration is applied when the optical fiber 13 is inserted or after insertion.

Therefore, the optical fiber 13 is not damaged by ultrasonic vibration, and the strength of the optical fiber 13 is not deteriorated.

FIGS. 5 and 6 show an example in which a tensile test was conducted on a sample in which zirconia ferrules 5 were soldered to both ends of an optical fiber core 11. The breaking strength of the solder fixed part was determined by passing light from an LED light source through the sample, simultaneously observing the tensile load and optical power, and determining whether the optical power was interrupted or decreased.

FIG. 5 shows the breaking strength of a sample of the conventional optical connector assembly method. Moreover, FIG. 6 shows the breaking strength of a sample of the optical connector assembly method shown in the embodiment of the present invention, and it can be seen that there is an improvement effect.

As described in the conventional example, the axial hole 9 of the ferrule 5 is filled with solder. Before inserting the optical fiber 13 into the axial hole 9 of the ferrule 5, the tip of the ferrule 5 is filled with glass J3 and ceramic bonding solder. For ultrasonic soldering that satisfies the above requirements, a method may be used in which the solder 8 is immersed in the solder bath 20 of the device, and the solder 8 is filled by applying ultrasonic vibrations. Further, an adhesive may be used to fix the ferrule support 6 and the optical fiber core 11.

The material of ferrule 1 is ceramic such as alumina or zirconia, or metal such as stainless steel or brass.

(Effects of the Invention) As explained above, according to the present invention, ultrasonic vibration is applied to the axial center hole of the ferrule in a heated state, τ melted solder is filled, and then, after stopping the ultrasonic vibration, Insert the optical fiber into the center hole of the ferrule.

The optical fiber is not damaged by ultrasonic vibration and the strength of the optical fiber is not deteriorated, which improves the reliability of the optical connector. There are advantages.

[Brief explanation of drawings]

Figure 1 is an apparatus configuration diagram for explaining the conventional method;
Figures 4 to 4 are process explanatory diagrams of the method of the present invention, Figure 5 is a graph showing the breaking strength of samples obtained by the method of assembling an optical cinema lid shown in the conventional example, and Figure 6 is the breaking strength of samples obtained by the method of the present invention. This is a graph without showing. 1... Ultrasonic chip, 2... Heater, 3... Horn, 4... Ultrasonic vibrator, 5... Ferrule, 6
... Ferrule support, 7... Heater, 8...
Solder, 9... Axial hole of ferrule, 10... Center hole of ferrule support, 11... Optical fiber core wire, 1
2... Optical fiber coating part, 13... Optical fiber, 1
4...Heat shrinkable tube, Patent applicant: Nippon Telegraph and Telephone Corporation (2 others) Agent: Patent attorney Yoshi 1) Yoshitaka Figure 1

Claims (1)

[Claims] The axial center hole of the ferrule is heated with a heater, and the molten solder is filled while applying ultrasonic vibration to the heated axial center hole.After that, the ultrasonic vibration is stopped and the optical fiber is inserted into the axial center hole. A method for assembling an optical connector, which comprises inserting the fiber into the ferrule, and fixing the optical fiber and the axial hole of the ferrule with solder.