KR100601033B1 - Optical Sub-AssemblyOSA module with passively aligned optical fibers - Google Patents

Abstract

The present invention relates to an optical device such as a transceiver optical sub-assembly (TOSA) and a receiver optical sub-assembly (ROSA), which are used to manufacture a transceiver module, which is a core part of an optical communication system, and includes a laser diode and a photodiode. By inserting an optical element such as an optical chip and a V-groove-shaped silicon substrate, the optical fiber is inserted into the V-groove at a predetermined position without using the optical lens and the lens cap, which are required for the conventional active optical alignment. It is to provide an optical module structure that can fabricate OSA (collectively, Optical Sub-Assembly, TOSA and ROSA) using only manual alignment. Utilizing the results of the present invention, the OSA manufacturing process can be simplified, downsized, and the manufacturing process time can be shortened, as well as the fabrication of low-cost and reliable passive alignment TOSA and ROSA.

Optical communication system, transmission and reception module

Description

Optical Sub-Assembly (OSA) module with passively aligned optical fibers}

Figure 1 (a) to Figure 1 (e) is a cross-sectional view showing the OSA assembly components and assembly process using a conventional TO package

2 is a cross-sectional view of a conventional peaktail optical module

Figure 3 (a) is a cross-sectional view of the OSA characterizing the present invention

Figure 3 (b) is an OSA stereogram showing the features of the present invention

Figure 4 (a) is a three-dimensional view and cross-sectional view immediately before assembling the silicon substrate and the receptacle (receptacle) of the present invention

4 (b) shows an example in which an error occurs when the optical fiber is inserted into the V-groove of the silicon substrate.

Figure 4 (c) is a cross-sectional view showing the principle of eliminating the optical fiber alignment error in accordance with the present invention

<Description of the code | symbol about the principal part of drawing>

1: TO package 2: laser diode chip

3: photodiode chip 4: optical lens for TO cap

5: TO lid 6: TO housing

7, 34: stub 8, 11, 33: optical fiber

9, 35: sleeve 10: housing for TOSA

12 fiber optic ferrule 13 ferrule housing

14 connector 31 silicon substrate

32: L-shaped block 101: optical element chip

102: silicon V-groove

The present invention relates to optical devices such as a transceiver optical sub-assembly (TOSA) and a receiver optical sub-assembly (ROSA), which are used to manufacture a transceiver module, which is a core component of an optical communication system, and is particularly simple and compact. The present invention relates to a structure and a manufacturing method of a low-cost and reliable passive alignment TOSA and ROSA.

Optical communication technology has been developed due to the need for rapid large-capacity information exchange, and the transmission speed of signals has been developed from the gigabit (Gbps) era to the terabit (Tbps) era. The development of the optical communication technology is now equipped with an environment that can be optical communication in the home, and has reached the age of FTTH (Fiber-To-The-Home) to install and use the optical transmission and reception module in each home. The need for optical communication transceivers in homes or offices is creating low cost, low cost optical transceiver modules (transceivers: TRx).

Optical transmitting / receiving module (abbreviated as TRx) is composed of TOSA for generating optical signal, ROSA for receiving optical signal and converting it into electric signal, and electronic circuit for generating and processing electric signal. The input and output terminals are standardized.

Therefore, TOSA and ROSA play a key role in TRx, and it is an important factor that determines the price of TRx.

Looking at the conventional technology of the structure and manufacturing method of TOSA and ROSA, a laser diode (LD) chip or photodiode (PD) chip is attached to a package called TO-CAN as a good electrical and thermally conductive material. After attaching the cap (Cap) attached to the lens on the TO-CAN and then to align and attach the optical fiber, this process will be described in detail with reference to Figure 1 as follows.

1 (a) to 1 (e) show a conventional TOSA manufacturing method.

First, as shown in Figs. 1A and 1B, a TO-CAN having a PD chip 3 attached thereto for monitoring the optical output of the LD chip 2 on the TO package 1, and an LD; The TO-cap (Cap) 5 with the lens 4 for collecting the optical signal transmitted from the chip 2 is assembled.

Subsequently, the assembled TO-CAN as shown in FIG. 1 (c) is fixed in a TO-housing 7 to align and attach with the optical fiber.

Finally, a receptacle composed of a stub 7, an optical fiber 8, a sleeve 9, and a housing 10 for TOSA, as shown in FIGS. 1 (d) and 1 (e); TO-housing 7 having the TO-CAN fixed in FIG. 1 (c) is precisely active aligned and welded with a laser welder.

Active light alignment is applied to the laser diode (2) attached to the TO package (1) to emit an optical signal when the light signal is emitted through a lens at a certain distance, the optical fiber is inserted here When (receptacle: Fig. 1 (e)) is aligned, the amount of optical signal entering the optical fiber is differently detected according to the degree of alignment, and the optical alignment method is used to find when the detected optical signal value is the largest. It is a method used in the alignment and packaging between optical elements.

In the case of ROSA, the alignment process is very similar to that of TOSA by aligning the PD with the receptacle inserted into the optical fiber.

As such, an active optical alignment method that directly drives an element such as a laser diode or a photodiode and detects an alignment with an optical fiber in real time to obtain an optimal alignment degree requires a lot of time and expensive assembly equipment in the manufacturing process. .

Figure 2 shows another embodiment of the conventional TOSA shows a TOSA in the form of permanent attachment of the optical fiber instead of the receptacle (receptacle) free to attach and detach the optical fiber, the manufacturing process is similar to FIG.

Whereas active light sorting method manufactures an optical device module by laser welding while detecting light output or photocurrent in real time, passive light sorting method is a method of aligning without directly driving an optical device. Whether it is using a robot with a bay or a worker's ability to assemble parts while looking at a microscope, it is a very advantageous method for mass production.

Conventional techniques for passive optical alignment methods require expensive robotic equipment called flip chip bonders, and in the case of the assembly process using flip chip bonders, reliable TOSA with an optical fiber stub is attached. / ROSA assembly parts could not be manufactured, but only to produce a pigtail type optical module that permanently attaches optical fibers.

The main reason why the passive optical alignment method has not advanced is that fabrication of the receptacle type TOSA and RSSA which can freely attach and detach the optical fiber has been very difficult in the conventional method.

Therefore, there is a need for a technique for creating and fabricating a new structure of TOSA and ROSA by a passive light alignment method which is very inexpensive and advantageous for mass production.

An object of the present invention devised to solve the above problems is to combine optical elements such as laser diodes and photo diodes and receptacle components attached to silicon substrates engraved with silicon V-grooves, but with additional lenses. And to manufacture TOSA / ROSA assembly parts quickly and simply by using a passive light alignment method without using a lens cap, and presenting a new TOSA and ROSA structure and providing a method of manufacturing the same.

The optical sub-assembly (OSA) module of the present invention as described above has an optical device chip attached to a part region and a V-groove for inserting and attaching an optical fiber to another part region. A receptacle comprising an engraved silicon substrate, an L-shaped metal block processed to have a bottom surface on which the silicon substrate is to be inclined at a predetermined angle with a horizontal plane, and an assembly of a stub surrounding the optical fiber and a sleeve surrounding the stub. Characterized in that configured.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 (a) is a cross-sectional view showing a cross section of the TOSA or ROSA of the present invention, Figure 3 (b) shows a three-dimensional view showing the overall appearance of the TOSA or ROSA.

As shown in FIGS. 3 (a) to 3 (b), an optical sub-assembly (TOSA and ROSA collectively) of the present invention has an optical device chip attached to a portion and a portion of another portion. Silicon substrate 31 engraved with a V-groove for inserting and attaching an optical fiber, and an L-shaped metal block processed so that the bottom surface on which the silicon substrate is located has an inclined surface at an angle of 1 to 15 degrees with a horizontal plane. And a receptacle composed of the assembly of the stub 34 surrounding the optical fiber 33 and the sleeve 35 surrounding the stub.

In the present invention, the bottom surface of the L-shaped metal block 32 to which the silicon device 31 to which the optical device chip is attached and the V-groove engraved is located is inclined at an angle of 1 to 15 degrees with respect to the horizontal. It is designed to have the elasticity of the optical fiber inserted into the silicon V-groove, which facilitates the assembly process of OSA (TOSA or ROSA) and provides mechanical stability against passive optical alignment after OSA assembly. It has the advantage of being very high.

4 to illustrate the features of the present invention in detail, as shown in Figure 4 (a) by inserting the optical fiber in the V-groove 102 on the silicon substrate 31 between the optical fiber core and the optical element When the silicon substrate and the optical fiber are placed in parallel in order to form the optical alignment, even if there is a slight height difference, the end of the optical fiber floats as shown in FIG. 4 (b), thereby causing optical coupling between the optical element and the optical fiber. It is difficult to achieve, and in order to control this, a lid for pressing an optical fiber on the V-groove may be used. At this time, the lid is bonded with a silicon substrate and an adhesive, but since the elasticity of the optical fiber is upward, it is subjected to mechanical stress due to temperature change, so that it is difficult to secure reliability and the yield may be reduced.

On the contrary, if the silicon substrate is attached at an angle to an angle as in the L-shaped block of the present invention, the end of the optical fiber is subjected to mechanical force in the bottom direction of the V-groove as shown in FIG. The optical coupling of the optical element and the optical fiber is automatically made by adjusting the depth of the V-groove, and the adjustment of the depth of the silicon V-groove is a very well known and easy technique. It becomes possible.

In the receptacle (receptacle) used in the present invention described above, the optical fiber sticks out of the stub several millimeters because it is inserted into a predetermined V-groove in the silicon substrate 31 and manually aligned. In the prior art, since the lens is used, the optical fiber does not need to stick out of the stub as illustrated in FIG.

In the present invention described above, the length of the optical fiber sticking out of the stub is about 1 to 10 mm.

In addition, although the receptacle used in the conventional OSA (TOSA or ROSA) fabrication is necessary for the OSA housing (Fig. 1 (d), 10) for laser welding, the receptacle (receptacle) used in the present invention described above In this case, since laser welding is not required, an OSA housing made of metal is not required, and thus, an additional cost reduction can be achieved.

As described above, the passively aligned OSA of the present invention (collectively referred to as TOSA or ROSA) has a structure using a passively aligned method of inserting an optical fiber into a silicon V-groove, so that additional lenses required for active aligned OSA are required. And it does not require a lens cap and does not require expensive equipment, and the manufacturing process is very simple, the mass productivity is greatly increased compared to the active alignment type, and the unit OSA assembly time is also greatly shortened. In addition, in order to produce an active aligned OSA, not only expensive equipment is required but also skilled workers dealing with expensive equipment, while in the present invention, the OSA can be manufactured with a simple basic education, which is very economical. Can be. In particular, in the passive alignment OSA structure of the present invention, since the bottom surface of the L-shaped metal block on which the silicon substrate is to be inclined at a predetermined angle, the lifting phenomenon of the optical fiber ends can be eliminated when combined with the optical fiber, thereby improving productivity and reliability. This has a very good structure.

Claims (4)

In the manual sub-assembly (OSA) module, A silicon substrate engraved with a V-groove for attaching an optical element chip to some areas and inserting and attaching an optical fiber to another area; An L-shaped metal block processed to have a bottom surface on which the silicon substrate is to be inclined at a predetermined angle with a horizontal surface, and Passive alignment of the module comprising a receptacle (receptacle) consisting of the assembly of the stub surrounding the optical fiber and the sleeve surrounding the stub. The method of claim 1, Passive alignment type OS module, characterized in that the angle is 1 ~ 15 degrees. The method of claim 1, Passive alignment type OS module, characterized in that the receptacle (receptacle) is a part of the optical fiber protruding out of the stub 1 ~ 10mm to be inserted into the V-groove on the silicon substrate. The method of claim 1, The optical device chip is a laser diode chip or a photodiode chip passive alignment type OS module, characterized in that.

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