JP2003172855A - Optical transceiver and method of manufacturing the same - Google Patents

Abstract

[PROBLEMS] To provide a low-cost and highly reliable multi-channel optical transceiver and a method of manufacturing the same. An optical signal input from a multi-core tape fiber is converted into an electric signal by a plurality of optical elements and output to the outside, or a plurality of electric signals input from the outside are converted. In an optical transceiver provided with an optical transmitting unit that converts each optical signal into an optical signal with the plurality of optical elements 20 and outputs the optical signal from the multi-core tape fiber 17, the end of the multi-core tape fiber 17 is branched into individual wires 19, Strand 19
The pitch converter 24 gradually changes the pitch of the optical element 20 from the pitch before branching to the pitch of the plurality of optical elements 20.
Is formed, and the pitch conversion section 24 is covered with a resin mold section 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transceiver used in an optical communication system such as an optical data link or an optical local network which uses light as an information transmission medium, and a manufacturing method thereof.

[0002]

2. Description of the Related Art A multi-channel optical transceiver converts a plurality of electrical signals input from the outside into optical signals by a plurality of light emitting elements and outputs the optical signals to the outside through each strand of a multi-core tape fiber. A single module has a transmitter and a receiver that receives a plurality of optical signals input from each strand of a multi-core tape fiber by a plurality of light receiving elements, converts them into electric signals, amplifies them, and outputs them to the outside. It is an optical module characterized by having a plurality.

In conventional multi-channel optical transceivers,
When connecting each element wire of a multi-core tape fiber and an optical element, the optical element array which has the same pitch as the pitch of each element wire of a multi-core tape fiber was used.

In this structure, since the pitch of each element wire of the multi-core tape fiber is equal to the pitch of the optical element, the coating of the multi-core tape fiber is removed and the end face of each fiber (element wire) is cut. The optical coupling was obtained simply by arranging them in the optical element array, and the structure was excellent in manufacturing workability.

However, in the optical element array, electrical isolation between channels is small and crosstalk occurs between the channels, so that it is difficult to perform high-speed signal processing.

Therefore, there has been proposed a multi-channel optical transceiver having a structure in which individual optical elements are arranged without using an optical element array and each element of the multi-core tape fiber is connected to each optical element. According to this structure, the optical elements are electrically independent as compared with the structure using the optical element array,
The isolation is large, and faster signal processing is possible.

However, when connecting the individual wires of a multi-core tape fiber to a single optical element, the pitch between the individual wires of a general tape fiber is about 250 μm, whereas the size of the optical element is about. Since it is as large as 300 μm, in consideration of the connection between the optical element and the integrated circuit, it is necessary to arrange the optical elements at intervals of about 400 μm or more. Therefore, in order to make the end face of the fiber (elementary wire) face the optical element in each channel, it is necessary to branch the multi-core tape fiber into individual elemental wires and hold the branched elemental wires at intervals of 400 μm.

Therefore, conventionally, a pitch converting jig having a plurality of grooves formed at a pitch equal to the pitch of the optical element is formed, and each element wire of the multi-core tape fiber is housed in the groove of the jig and the A method of holding the element at the same pitch as each other, aligning and fixing the respective element wires on the optical element mounting substrate, and then removing the jig has been adopted.

Further, a pitch converting component having a plurality of grooves formed at a pitch equal to the pitch of the optical element is prepared,
A method has also been used in which each element wire is housed in the groove of the pitch exchange component, the element wire and the optical element are coupled, and then the pitch conversion element is fixed to the case.

Here, a conventional method of manufacturing a multi-channel optical transceiver using a pitch converting jig will be described with reference to FIGS.

As shown in FIG. 7, the multi-channel optical transceiver is roughly composed of an optical device mounting board 1, an integrated circuit 2, an electric circuit board 3, a multi-core tape fiber 4 and a case 5. .

As shown in FIG. 9, the manufacturing method is as follows. First, as shown in FIG. 9, the end portion of the multifilamentary tape fiber 4 is branched into a predetermined length into each strand 6, 6 ,. It is stored in the jig 9.

The pitch converting jig 9 has a plurality of element wire accommodating grooves 8 formed at a pitch equal to the pitch of the optical elements 7, 7, ... Mounted on the optical element mounting substrate 1 shown in FIGS.
.. and a lid 9b attached to the body 9a.
Are housed in the wire housing grooves 8, 8 ,. As a result, the pitch of each of the element wires 6, 6, ... Is larger than that before branching, and the element wires 6, 6, ... Mounted on the optical element mounting substrate 1 are arranged at the same pitch.

After that, the lid portion 9b is attached to the main body portion 9a to fix the individual wires 8, 8, ... (FIG. 10).

Next, the coating of each of the strands 6, 6, ... Extending from the end portion of the pitch conversion jig 9 is removed and the fibers 11, 1 are removed.
1, ... Are exposed, and the fibers are cut so that the end faces 11a of the respective fibers 11 are aligned on a straight line (FIG. 11).

The optical element mounting substrate 1 and the integrated circuit 2 are provided in the case 5.
After fixing the electric circuit board 3 and the fibers 11, 11, ... Fixed by the pitch conversion jig 9 along the fiber guide groove 12 (see FIG. 8) formed in the optical element mounting board 1. , End faces 11 of the fibers 11, 11, ...
Position a so as to face the optical element 7 of each channel (FIG. 12). At this time, the alignment is performed so that the distance between the fiber end surface 11a and the optical element 7 in each channel is approximately 20 μm.

Then, the glass plate 13 presses the fiber 11 into the fiber guide groove 12 of the optical element mounting substrate 1,
After fixing each fiber 11 with an ultraviolet curable resin or the like, the lid 9b is removed from the main body 9a, and the pitch conversion jig 9 is removed from the case 5 (FIGS. 7 and 8).

[0018]

However, in such a conventional multi-channel optical transceiver, since bending is performed to change the pitch of each strand 6 of the multi-core tape fiber 4, bending stress is applied to each strand 6. Occurs, and as a result,
There has been a problem that bending stress may concentrate on the portion of the fiber 11 from which the coating having low rigidity has been removed and may break.

Further, in the method of fixing the pitch conversion component to the case, since the pitch of the strands is changed in the pitch conversion component, bending stress is not applied to the fiber portion where the coating is removed, and the problem of breakage occurs. However, there was a problem that the cost was increased because the number of parts increased.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a low cost and highly reliable multi-channel optical transceiver and a manufacturing method thereof.

[0021]

In order to achieve the above object, the present invention converts an optical signal input from each element wire of a multi-core tape fiber into an electric signal by a plurality of optical elements, and outputs the electric signal. An optical receiver that outputs a signal to the outside, or an optical signal that converts multiple electrical signals input from the outside into optical signals with multiple optical elements and outputs the optical signals from each strand of the multi-core tape fiber. In an optical transceiver provided with a transmitter, the end of the multi-core tape fiber is branched into individual strands, and the pitch between the individual strands is changed from the pitch before branching to the pitch equal to the pitch of the plurality of optical elements. The pitch converting portion is gradually changed, and the pitch converting portion is covered with the resin mold portion.

According to this structure, since the bending stress generated by converting the pitch of each strand can be absorbed by the resin mold portion, stress is not applied to the fiber portion where the coating is removed, and the fiber breaks. Can be prevented. Further, the number of parts is smaller than that of the structure in which the pitch conversion parts are fixed to the case, so that the manufacturing cost can be reduced.

Further, according to the present invention, an optical receiving section for converting an optical signal inputted from each element wire of the multi-core tape fiber into an electric signal by a plurality of optical elements and outputting the electric signal to the outside, or In a method of manufacturing an optical transceiver including an optical transmitter that converts a plurality of electric signals input from the outside into optical signals with a plurality of optical elements, and outputs the optical signals from each strand of a multi-core tape fiber, The end portion of the multifilamentary tape fiber is branched into individual strands, and the pitch between the individual strands is gradually changed from the pitch before branching to the pitch equal to the pitch of the plurality of optical elements to form the pitch conversion unit. It is formed and the pitch conversion portion is molded with resin.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view of a multi-channel optical transceiver according to this embodiment, and FIG. 2 is an enlarged view of the optical element mounting substrate in FIG.

The multi-channel optical transceiver of this embodiment has the same basic configuration as the conventional multi-channel optical transceiver shown in FIG. 7, and has an optical element mounting board 14, an integrated circuit 15, and an electric circuit board 16. And a multi-core tape fiber 17 and a case 18.

The optical element mounting board 14, the integrated circuit 15 and the electric circuit board 16 are fixed on a case 18, and the end portions 27a of the respective fibers 27, 27, ... Of the multi-core tape fiber 17 are attached to the optical element mounting board 14. Optical element 2 mounted on top
It is provided so as to face 0, 20, ....

The optical element 20 is a light emitting element for converting an electric signal inputted from the outside into an optical signal, or an optical signal inputted from each fiber 27, 27, ... Of the multi-core tape fiber 17 is converted into an electric signal. It is a light receiving element for conversion, and a light emitting element is an optical semiconductor laser diode (L
D) or a light emitting diode or the like is used, and as the light receiving element, an avalanche photodiode (APD) or a pin photodiode (pin-PD) or the like is used.

The multi-channel optical transceiver of the present invention is different from the conventional one in that the pitch of each of the strands 19, 19, ... Of the multi-core tape fiber 17 is the pitch before branching (about 250).
μm) to the optical element 2 mounted on the optical element mounting substrate 14
The pitch conversion part that is gradually changed to a pitch equal to 0 pitch (400 μm or more) is covered with the resin mold part 26.

Specifically, the resin mold portion 26 is arranged at the same pitch as the optical element 20 and the first mold portion 26a covering the curved portion for changing the pitch of the strands 19, 19 ,. Second mold part 2 covering the straightened part
6b and.

By covering the curved portion of the wire 19 with the first mold portion 26a, the bending stress generated in the wire 19 is absorbed by the first mold portion 26a, and the bending stress is applied to the portion of the fiber 27 having low rigidity. This is not the case.
Therefore, it is possible to prevent the fiber 27 from breaking.

Further, by covering the straight line portions arranged at the same pitch as the optical element 20 with the second mold portion 26b as a whole, the root portions of the individual wires 19 extending from the first mold portion 26a and the fibers. It is possible to prevent stress from concentrating on the fixed portion of 27.

Next, a method of manufacturing this multi-channel optical transceiver will be described.

First, as shown in FIG. 3, the end portion of the multi-core tape fiber 17 is branched into a predetermined length into each of the strands 19, 19, ... And the branched portion is housed in the molding die 22.

The mold forming die 22 is composed of a lower die 22a and an upper die 22b, and the lower die 22a contains a tape containing portion 3 for containing the multifilamentary tape fiber 17 in the unbranched portion.
0 and the optical element mounting substrate 21 formed on the optical element mounting substrate 14 shown in FIGS. 1 and 2 and having the same pitch as the optical elements 20, 20 ,. The first molding portion 31 that accommodates the pitch conversion portion 24 that is curved so that the pitch of 19 is gradually changed from the pitch before branching to the pitch that is equal to the pitch of the optical element 20, and the strand forming groove 21 is orthogonal so as to be continuous. And a second molding portion 32 formed by the above. On the other hand, the upper mold 22b is the first molding part 31 of the lower mold 22a.
And the through hole 23 formed in conformity with the second molding portion 32
(In the figure, only those formed in accordance with the first molding portion 31 are shown).

The non-branched part of the multi-core tape fiber 17 is accommodated in the tape accommodating portion 30, and the branched filaments 19, 19, ... Are accommodated in the respective filament accommodating portions 21, 21 ,. . As a result, the pitch of each element wire 19 becomes larger than that before branching, and the element wires 19 are arranged at the same pitch as that of each of the optical elements 20, 20, ... Further, the pitch conversion unit 24 of the wire 19 is housed in the first molding unit 31, and a part of each wire 19 housed in the wire housing unit 21 is housed in the second molding unit 32.

Next, the upper die 22b is mounted on the lower die 22a to fix the strands of wire 19, 19, ... And to seal the first molding portion 31 and the second molding portion 32. And the upper mold 22
The molding resin 25 is injected from the through hole 23 of b, the air bubbles are removed from the resin by vacuum defoaming, and the resin molding portion 26 is created by heat curing (FIG. 4).

The multi-core tape fiber 17 on which the resin mold portion 26 is formed is taken out from the mold forming die 22,
The coating of the strands 19, 19, ... Extending from the second mold portion 26b of the resin mold portion 26 is removed to remove the fiber 27,
27, ... Are exposed, and the end faces 27a of the respective fibers 27 are exposed.
The fibers are cut so that they are aligned on a straight line (FIGS. 5 and 6).

After fixing the optical element mounting substrate 14, the integrated circuit 15 and the electric circuit board 16 to the case 18, the respective fibers 27, 27, fixed by the resin mold portion 26 at the same pitch as the optical elements 20, 20 ,. Is a fiber guide groove 28 formed in the optical element mounting substrate 14 (see FIG. 2)
, And the end faces 27a of the fibers 27, 27, ... Are positioned so as to face the optical element 20 of each channel. At this time, the alignment is performed so that the distance between the fiber end face 27a and the optical element 20 in each channel is approximately 20 μm.

Then, as shown in FIG.
Then, the fibers 27 are pressed into the fiber guide grooves 28 of the optical element mounting substrate 14, and the respective fibers 27 are fixed by an ultraviolet curable resin or the like.

Finally, the resin mold portion 26 is fixed to the case.

As described above, by resin-molding the pitch converting portion (curved portion) 24 of each strand 19 of the multi-core tape fiber 17, the bending stress generated in the strand 19 can be absorbed by the resin molding portion 26, Fiber 2 with coating removed
No stress is applied to 7. Therefore, breakage of the fiber 27 can be prevented. Further, the number of parts is smaller than that of the structure in which the pitch conversion parts are fixed to the case, so that the manufacturing cost can be reduced.

[0043]

In summary, according to the present invention, it is possible to provide a highly reliable multi-channel optical transceiver at a low cost, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a perspective view of a multi-channel optical transceiver according to an embodiment of the present invention.

FIG. 2 is an enlarged view of the optical element mounting substrate in FIG.

FIG. 3 is a perspective view illustrating a method for manufacturing a multi-channel optical transceiver of the present invention, showing a state in which a multi-core tape fiber is housed in a mold.

FIG. 4 is a perspective view illustrating a method for manufacturing a multi-channel optical transceiver of the present invention, showing a state where a molding resin is injected into a mold.

FIG. 5 is a perspective view illustrating a method for manufacturing a multi-channel optical transceiver of the present invention, showing a multi-core tape fiber in which a resin mold portion is formed.

FIG. 6 is a perspective view illustrating a method for manufacturing a multi-channel optical transceiver of the present invention, showing a state in which an end face of a fiber extending from a resin mold portion is cut.

FIG. 7 is a perspective view of a conventional multi-channel optical transceiver.

8 is an enlarged view of the optical element mounting substrate in FIG.

FIG. 9 is a perspective view for explaining a conventional method for manufacturing a multi-channel optical transceiver, showing a multi-core tape fiber branched into individual strands and a pitch conversion jig.

FIG. 10 is a perspective view for explaining a conventional method for manufacturing a multi-channel optical transceiver, showing a state in which each strand of a multi-core tape fiber is fixed by a pitch conversion jig.

FIG. 11 is a perspective view illustrating a conventional method for manufacturing a multi-channel optical transceiver, showing a state in which an end face of a fiber extended from a pitch conversion jig is cut.

FIG. 12 is a perspective view for explaining a conventional method for manufacturing a multi-channel optical transceiver, showing a state in which a fiber fixed by a pitch conversion jig faces an optical element.

[Explanation of symbols]

14 Optical element mounting board 15 Integrated circuit 16 Electric circuit board 17 Multi-core tape fiber 19 strands 20 optical elements 22 Mold Mold 26 Resin mold part 27 fibers

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H037 AA01 BA05 BA14 BA35 DA03                       DA04 DA06 DA12 DA17                 5F041 DA19 DA20 DA82 EE02 EE06                       FF14                 5F088 BA16 EA02 JA14 JA20                 5F089 AA01 AC17 AC24 EA04

Claims (2)

[Claims] 1. An optical receiving unit for converting an optical signal input from each strand of a multi-core tape fiber into an electric signal by a plurality of optical elements and outputting the electric signal to the outside, or an input from the outside. An optical transceiver including an optical transmitter that converts a plurality of electric signals to optical signals by a plurality of optical elements, and outputs the optical signals from each strand of the multi-core tape fiber, An end portion is branched into each element wire, and a pitch conversion section in which the pitch between the element wires is gradually changed from the pitch before branching to the pitch equal to the pitch of the plurality of optical elements is formed. An optical transceiver characterized in that the resin is covered with a resin mold part. 2. An optical receiving unit for converting an optical signal input from each strand of a multi-core tape fiber into an electric signal by a plurality of optical elements and outputting the electric signal to the outside, or an input from the outside. In the method for manufacturing an optical transceiver including an optical transmitter that converts a plurality of electric signals to optical signals by a plurality of optical elements, and outputs the optical signals from each strand of a multicore tape fiber, the multicore The end portion of the tape fiber is branched into each strand, the pitch between each strand is gradually changed from the pitch before branching to a pitch equal to the pitch of the plurality of optical elements to form a pitch conversion unit, A method for manufacturing an optical transceiver, wherein the pitch conversion portion is molded with resin.