KR100551548B1 - Optical sub-assembly(osa) module with passive optical alignment and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to an optical device such as a transmitter 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 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 manufacture integrated OSA (integrating TOSA and ROSA) using only manual alignment. Utilizing the results of the present invention, the OSA manufacturing process can be simplified, downsized, and can shorten the manufacturing process time, and it is possible to manufacture a low-cost and reliable manual alignment integrated OSA.

Optical communication system, transmission and reception module

Description

Optical sub-assembly (OSA) module with passive optical alignment and method for manufacturing applications

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 pigtail type optical module

3 (a) and 3 (b) are a perspective view and a plan view of the OSA according to the present invention.

3 (c) and 3 (d) are cross-sectional views of the OSA according to the present invention taken along planes A-A and B-B.

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

<Explanation of symbols for main parts of drawing>

1: TO package 2: laser diode chip

3: photodiode chip 4: lens

5: TO lid 6: TO housing

7, 35: stub 8, 11, 34: optical fiber

9, 36: sleeve 10: housing for TOSA

12: optical fiber ferrule 13: ferrule housing

14 connector 15 TO housing

31: light-receiving silicon substrate 32: light-emitting silicon substrate

33: L-shaped metal block 37: Receptacle

38: spring steel 39: bolt

101: optical device chip 102: V-groove

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to optical devices such as TOSA (Transmitter Optical Sub-Assembly) and ROSA (Receiver Optical Sub-Assembly), which are used to manufacture a transceiver module, which is a core component of an optical communication system. The present invention relates to an inexpensive and reliable passive alignment integrated OSA (TOSA and ROSA integration) module and a method of manufacturing the same.

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 has now become an environment that can be optical communication in the home, and 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 a 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 PD chip 3 for monitoring the light output from the LD chip 2 and the LD chip 2 is attached to the TO package 1. Then, the TO-cap (Cap) 5 with the lens 4 for collecting the optical signal transmitted from the LD chip 2 is assembled.

Subsequently, the assembled TO-CAN as shown in FIG. 1 (c) is fixed in a TO-housing 6 made of metal to align and attach the optical fiber.

Finally, a receptacle consisting of a stub 7, an optical fiber 8, a sleeve 9, and a metal housing 10 for TOSA, as shown in FIGS. 1 (d) and 1 (e). ) And the TO-housing (TO-housing, 6) in which the TO-CAN of FIG. 1 (c) is fixed are welded with a laser welder after precise active alignment.

In active light alignment, when a current is applied to the LD chip 2 attached to the TO package 1 to emit an optical signal, the emitted optical signal forms a phase at a predetermined distance through the lens, and an optical fiber is inserted therein. 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 it is an optical alignment method that finds 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. .

FIG. 2 illustrates another embodiment of the conventional TOSA, and illustrates a TOSA in which a fiber is permanently attached instead of a receptacle free to attach and detach an optical fiber, and a manufacturing process is similar to that of FIG. 1. That is, the assembly is carried out in the same manner as in Fig. 1 (a) to Fig. 1 (c), but in Fig. 2, the TO housing (for optical fiber attachment) 15 is slightly different from Fig. 1 (c). Next, active optical alignment is performed while the optical fiber ferrule 12 is inserted into the ferrule housing 13, and laser welding is performed at an optimal position to melt each component to fabricate an optical fiber attachment TOSA.

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. It is a technique that assembles parts by using a robot by using a bay or a worker by looking at a microscope, which is very advantageous for mass production.

Conventional techniques for passive optical alignment require expensive robotic equipment, called flip chip bonders, and reliable TOSA with fiber stubs for the assembly process using flip chip bonders. / 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 ROSA capable of freely attaching and detaching optical fibers has been very difficult in the conventional method.

Therefore, there is a need for a technique for creating and manufacturing 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 a laser diode and a photo diode and a receptacle component attached to a silicon substrate engraved with a silicon V-groove, but additional lenses And to manufacture TOSA and ROSA assembly parts quickly and easily by using a manual light alignment method without using a lens cap, and presenting a new TOSA and ROSA structure and providing a method of manufacturing the same.

Manual sub-assembly (OSA) module of the present invention for achieving the above object is a photosensitive silicon substrate engraved V-groove is attached to the light-receiving element chip and can be attached to the optical fiber; A light emitting silicon substrate on which a light emitting device chip is attached and engraved with a V-groove for inserting and attaching an optical fiber; A stub surrounding the optical fiber; Two receptacles comprising assembly of a sleeve surrounding the stub; An L-shaped metal block fabricated so that the silicon substrates can be located respectively and a receptacle corresponding to each silicon substrate can be located; And a spring steel and a bolt for tightly attaching the optical fiber to the V-groove.

The L-shaped metal block is characterized in that the distance between the V-groove of the silicon substrate and the optical fiber bottom of the receptacle is adjusted to about 0.01 ~ 0.5mm.

In addition, a method for manufacturing an optical sub-assembly (OSA) module for the purpose of achieving the above object is inserted into the stub so that the optical fiber is protruded by a certain length and then assembled into a receptacle together with the sleeve. Steps; Inserting the receptacle into an L-shaped metal block to assemble an OSA body; Light-receiving silicon substrate with a V-groove to which the light-receiving device chip is attached and the optical fiber can be inserted and attached to the OSA main body, and the light-emitting silicon with the V-groove to which the light emitting device chip is attached and the optical fiber can be inserted and attached. Applying an adhesive to the bottom of the substrate and positioning the optical fiber to be inserted into the silicon V-groove; Placing a spring steel on the optical fiber and pressing the bolt with the bolt to bring the optical fiber into close contact with the V-groove, thereby simultaneously aligning the light-receiving and light-emitting silicon substrates; A fifth step of fixing the bolt by adding an adhesive to the bolt; And a sixth step of adding a transparent epoxy where the end of the optical fiber and the V-groove meet.

It is characterized in that the optical fiber is inserted into the stub to protrude by 1 ~ 10mm length.

The L-shaped metal block is processed to be assembled so that the distance between the V-groove and the bottom surface of the optical fiber of the receptacle is about 0.01 ~ 0.5mm.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Parts having the same structure and the same action are given the same reference numerals.

Figure 3 (a) is a three-dimensional view of the overall appearance of the OSA of the present invention, Figure 3 (b) is a plan view of the OSA, Figure 3 (c) is a cross-sectional view taken in AA plane of the OSA of the present invention 3 (d) Is a cross-sectional view of the OSA taken along the BB plane.

As shown in Figs. 3 (a) to 3 (d), the passive alignment integrated OSA of the present invention has a V-groove in which an optical device chip is attached to a part of the region and an optical fiber is inserted into the other part of the region. The light-receiving and light-emitting silicon substrates 31 and 32 having the grooves 102 engraved thereon and the light-receiving and light-emitting silicon substrates 31 and 32 are placed on the bottom surface of the optical fiber 34 and the light-receiving and light-emitting silicon substrates. The L-shaped metal block 33 and the stub 35 and the stub 35 surrounding the optical fiber 34 are machined so that the receptacle 37 is assembled so as to be separated from each other by 0.01 to 0.5 mm. Receptacle 37 consisting of an assembly of a sleeve 36 enclosing the &lt; RTI ID = 0.0 &gt;), &lt; / RTI &gt; and spring steel 38 for bringing the optical fiber 34 into close contact with the V-grooves 102 of the light-receiving and emitting silicon substrates 31, 32. And it is characterized by consisting of a bolt (39).

Referring to Figure 3 (a) to Figure 3 (d) describes a process of manufacturing a manual sub-assembly (OSA) module to which the present invention is applied as follows.

First, the optical fiber 34 is inserted into the stub 35 so that a predetermined distance, preferably between 1 and 10 mm, is assembled into the receptacle 37 together with the sleeve 36. The manufactured receptacle 37 is inserted into the L-shaped metal block 33 to complete the OSA body.

The light-receiving silicon chip 31 is engraved with the V-groove 102 for attaching and attaching the optical fiber 34 to the light-receiving element chip in some areas and the light-emitting device chip is attached to the other area In some areas, the adhesive is applied to the bottom of the light emitting silicon substrate 32 having the V-groove 102 into which the optical fiber 34 can be inserted and attached, and then the optical fiber 34 is inserted into the silicon V-groove 102. Position it as possible.

The spring steel 38 is placed on the optical fiber 34 and pressed with a bolt 39 so that the optical fiber 34 is in close contact with the silicon V-groove 102 so that the light receiving silicon substrate 31 and the light emitting silicon substrate 32 are formed. Align simultaneously and fix it so that it does not move by adding adhesive to the bolt (39).

Finally, the optical sub-assembly (OSA) module is incorporated by adding a transparent epoxy at the end of the optical fiber 34 and the silicon V-groove 102 to reduce reflection at the optical fiber 34 end. To complete.

In the present invention, the optical element 34 is attached to the light-receiving and light-emitting silicon substrates 31 and 32 having the V-groove 102 engraved therein by pressing the optical fiber 34 with the spring steel 38 and the bolt 39. The method of contacting the photovoltaic device is to simplify the process of simultaneously fixing the light-receiving silicon substrate 31 and the light-emitting silicon substrate 32 and to provide mechanical stability against manual light alignment after assembling the OSA, thereby greatly increasing the reliability of the OSA module. Has the advantage.

Figure 4 (a) is a three-dimensional view and a cross-sectional view immediately before inserting the optical fiber to the silicon substrate of the present invention, Figure 4 (b) is an example of an error occurs when the optical fiber is inserted into the alignment of 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.

To illustrate the features of the present invention in detail with reference to Figure 4, as shown in Figure 4 (a), the optical fiber 34 in the V-groove 102 on the light-receiving and light-emitting silicon substrate (31, 32) When the light receiving and light emitting silicon substrates 31 and 32 and the optical fiber 34 are parallel to each other in order to form a light alignment between the optical fiber 34 core and the optical device chip 101, the height is slightly higher. Even if there is a difference, as shown in FIG. 4 (b), the end of the optical fiber 34 is raised, making it difficult to achieve optical coupling between the optical element chip 101 and the optical fiber 34. A lid or the like for pressing the optical fiber 34 on the groove 102 may be used. At this time, the lid is adhered to the light-receiving silicon substrate 31 with an adhesive, but since the elasticity of the optical fiber 34 is directed upward, it is difficult to secure reliability due to mechanical stress caused by temperature change, etc., and the yield may be reduced.

On the contrary, in the case of processing the component so that the optical fiber is slightly dropped upward from the V-groove 102 as in the present invention and pressing the optical fiber 34 using the spring steel 38 as shown in FIG. 4 (c). The restoring force of the spring steel 38 pushes the end of the optical fiber 34 toward the bottom of the V-groove 102 so that it receives a moderate mechanical force, and V- on the light-receiving and light-emitting silicon substrates 31 and 32. The optical coupling of the optical element to the optical fiber is automatically made by adjusting the depth of the groove 102, and the depth control of the V-groove 102 is a very well known and easy technique, so it is designed to have high reliability and mass productivity. Can be adjusted in stages.

In the receptacle 37 used in the present invention, the optical fiber 34 is protruded several millimeters out of the stub 35 because the V-groove predefined in the light receiving and light emitting silicon substrates 31 and 32. It is for inserting into 102 and performing manual alignment, and since the conventional technique uses a lens, the optical fiber does not need to pop out of the stub 35 as illustrated in Fig. 1 (d).

In the present invention described above, the length of the optical fiber 34 that protrudes out of the stub 35 is about 1 to 10 mm.

As described above, the passive alignment integrated OSA of the present invention (TOSA / ROSA integration) has a structure using a passive alignment method of inserting an optical fiber into the silicon V-groove, so that additional lenses and lenses required by the active alignment OSA are required. No caps are required, no expensive equipment is required, and the manufacturing process is very simple, greatly increasing the productivity compared to the active alignment type, and significantly reducing the unit OSA assembly time. In addition, in order to produce an active alignment OSA, not only expensive equipment is required, but also skilled workers dealing with expensive equipment, while in the present invention, OSA can be manufactured with a simple basic education, which is very economical. Can be. In particular, in the passive alignment integrated OSA structure of the present invention, by pressing the optical fiber located in the V-groove of the silicon substrate with the spring steel, the lifting phenomenon of the optical fiber ends can be eliminated as well as the light-receiving (receiving) silicon substrate and the light emitting device. Simultaneously pressing two optical fibers on a silicon substrate results in a highly productive and reliable structure.

In addition, in the prior art, since TOSA and ROSA were manufactured and used separately, the optical module manufacturing process that requires relatively large volume and soldering is complicated, while in the present invention, the TOSA and ROSA are integrated into a single OSA to reduce volume and reduce modules. The assembly process time can also be significantly reduced.

Claims (5)

In the manual sub-assembly (OSA) module, A light-receiving silicon substrate having a V-groove to which a light receiving element chip is attached and to which an optical fiber can be inserted; A light emitting silicon substrate on which a light emitting device chip is attached and engraved with a V-groove for inserting and attaching an optical fiber; A stub surrounding the optical fiber; Two receptacles comprising assembly of a sleeve surrounding the stub; An L-shaped metal block fabricated so that the silicon substrates can be located respectively and a receptacle corresponding to each silicon substrate can be located; And And a spring steel and a bolt for tightly attaching the optical fiber to the V-groove. The method of claim 1, The L-shaped metal block is passive alignment integrated OS module, characterized in that the distance between the V-groove of the silicon substrate and the optical fiber bottom of the receptacle is adjusted to about 0.01 ~ 0.5mm. In the manufacturing method of the manual sub-assembly (OSA) module, Inserting the optical fiber into the stub so that the optical fiber is protruded by a predetermined length, and then assembling the receptacle together with the sleeve; Inserting the receptacle into an L-shaped metal block to assemble an OSA body; Light-receiving silicon substrate with a V-groove to which the light-receiving device chip is attached and the optical fiber can be inserted and attached to the OSA main body, and the light-emitting silicon with the V-groove to which the light emitting device chip is attached and the optical fiber can be inserted and attached. Applying an adhesive to the bottom of the substrate and positioning the optical fiber to be inserted into the V-groove; Placing a spring steel on the optical fiber and pressing the bolt with the bolt to bring the optical fiber into close contact with the silicon V-groove to simultaneously align the light-receiving and light-emitting silicon substrates; A fifth step of fixing the bolt by adding an adhesive to the bolt; And And a sixth step of adding a transparent epoxy where the end of the optical fiber and the V-groove meet each other. The method of claim 3, Method for manufacturing a passive alignment integrated OS module, characterized in that the length that the optical fiber can protrude by a predetermined length is 1 ~ 10mm. The method of claim 3, Wherein the L-shaped metal block is a manual alignment integrated OS module manufacturing method characterized in that the distance between the V-groove and the bottom surface of the optical fiber of the receptacle is assembled to about 0.01 ~ 0.5mm.

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