JPH09105839A - Semiconductor optical coupling device and its assembling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor coupling device which is easily handled and high in reliability by previously fixing an optical fiber in a stepped cylindrical ferrule, and then adjusting the optical axis to the projection light from a semiconductor laser joined to the same substrate and joining and fixing the optical fiber. SOLUTION: The semiconductor laser 1 is joined to the Si substrate 2 at a specific position and the stepped ferrule 3 where the optical fiber is fixed to a V groove formed previously in the Si substrate 2. A frame 4 is provided previously from the reverse surface to a lateral side of the Si substrate 2. The optical fiber is fixed in the stepped ferrule 3 and a thin-diameter part of the stepped ferrule 3 is fixed to the V groove of the Si substrate 2. A large-diameter part is fixed abutting against the frame 4. The semiconductor laser 1 and optical fiber are fixed at the specific position of the Si substrate 2 and optically coupled together. The fiber is neither flawed nor damaged with external humidity at the time of the assembly, and the device is easily assembled in a short time to improve the yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor optical coupling device for coupling light through an optical fiber, and more particularly, it is suitable for joining and fixing the optical fiber to the optical coupling device and connecting to the outside with a connector. The present invention relates to a semiconductor optical coupling device and a method for assembling the same.

[0002]

2. Description of the Related Art Conventionally, in a device for optically coupling light emitted from a semiconductor laser to an optical fiber, for example, 1994.
NEC Technical Report, Vol.47, No.12 "Surface Mount LD
As described in "/ PD module", the LD element is S-coupled so that the oscillation light of the LD element can be efficiently optically coupled to the fiber.
It is mounted on the i substrate and the single mode fiber is fixed in the V groove of the same Si substrate. Further, in order to connect to an external fiber, the fiber extending to the outside of the lid is fixed in the ferrule and then coupled to the connector.

[0003]

The above conventional technique is shown in FIG.
As shown in, the light beam emitted from the LD element is condensed by the heated spherical lens and is taken into the optical fiber. The position of the optical fiber is positioned by the V groove provided on the Si substrate. The fiber fixed by the V groove is extended to the outside of the lid 22 and fixed in the ferrule. Ferrule 2
3 is fixed to the module body. The ferrule 23 provided in the module has a structure in which it is connected to an external connector via a split sleeve 24.

By the way, as the function of the module, LD
It has a function of coupling the emitted light from the element into the fiber as efficiently as possible and easily connecting the incident light to an external fiber. That is, looking at the fixing state of the entrance end and the exit end of the fiber attached to the module, the entrance fiber tip of the optical fiber is fixed by the V groove provided on the Si substrate, and the exit fiber tip of the optical fiber is It is fixed inside the ferrule and on the module body. However, one of the optical fibers is fixed to the V groove,
The other is fixing in the ferrule, and in the middle part, fixing at the lower part of the lid and fixing at at least 3 places, there is a problem that the fiber fixing work is difficult. Also at least 3
There was also a possibility of damaging the fiber when fixing the place. Furthermore, there is no disclosure of fiber incorporation in the known example. Further, although the spring force is always applied to the ferrule 23 from the external connector, there is a problem that the stability of the ferrule 23 to the main body module 30 is not explained when the spring force is applied.
Further, when the fiber 26 is fixed to the V groove and then the lid 22 is attached and the resin is hermetically used for a long period of time, moisture may enter from the resin portion, which may affect the fixing of the fiber. Is not explained at all.

An object of the present invention is to provide a semiconductor optical coupling device for coupling light through an optical fiber, which is suitable for joining and fixing the optical fiber to the optical coupling device and for connector connection to the outside. And a method of assembling the same.

[0006]

The above-mentioned object is, for example, as shown in the sectional view of FIG. 1, a semiconductor laser 1 is bonded to a predetermined position of a Si substrate 2, and a V groove formed in the Si substrate 2 in advance is connected to the semiconductor laser 1. , The stepped ferrule 3 to which the optical fiber is fixed is fixed. The frame 4 extends from the rear surface of the Si substrate 2 to the lateral side surface.
Is provided in advance. The optical fiber is fixed in the stepped ferrule 3, and the small diameter portion of the stepped ferrule 3 is fixed in the V groove of the Si substrate 2. The thick diameter portion is fixed so as to hit the frame 4. Semiconductor laser 1
Also, the optical fiber is fixed at a predetermined position on the Si substrate 2 to perform optical coupling. On the other hand, the connection with the external connector is achieved by connecting with the thick diameter portion of the stepped ferrule 3.

That is, according to the present invention, in a semiconductor optical coupling device comprising a semiconductor laser, a monitor photodiode, and an optical fiber mounted on the same substrate, and a case mounted so as to accommodate the substrate, the optical fiber is previously provided. After being fixed in the stepped cylindrical ferrule, the optical axis of the light emitted from the semiconductor laser bonded to the same substrate is adjusted, and the fiber with the cylindrical ferrule is bonded and fixed onto the substrate.

Further, the present invention is a semiconductor optical coupling device comprising a case in which a semiconductor laser, a monitoring photodiode, and an optical fiber are mounted on the same substrate, and the substrate is mounted so as to be housed therein. After being fixed in the attached cylindrical ferrule, the optical axis of the light emitted from the semiconductor laser joined to the same substrate is adjusted, and the fiber with the cylindrical ferrule is joined and fixed in the stepped groove formed at a predetermined position on the substrate. Is.

Further, according to the present invention, in a semiconductor optical coupling device comprising a case in which a semiconductor laser, a monitoring photodiode and an optical fiber are mounted on the same substrate and attached so as to house the substrate, a semiconductor optical coupling device is provided at a predetermined position on the substrate. Join the semiconductor laser to the provided semiconductor laser bonding marker, then
The optical fiber previously fixed in the stepped cylindrical ferrule is fixed to the stepped groove formed at a predetermined position of the substrate.

Further, according to the present invention, a semiconductor laser, a monitor photodiode, and an optical fiber are mounted on the same substrate, and a frame provided to hold the substrate and a frame-mounted substrate are attached so as to be housed. In a semiconductor optical coupling device including a case, a semiconductor laser is bonded to a semiconductor laser bonding marker provided at a predetermined position of the framed substrate, and then a step is formed at a predetermined position of the framed substrate. The optical fiber previously fixed in the stepped cylindrical ferrule is installed and fixed in the groove.

Further, according to the present invention, a semiconductor laser, a monitor photodiode, and an optical fiber are mounted on the same substrate, and a frame provided to hold the substrate and a frame-mounted substrate are attached so as to be housed. In a semiconductor optical coupling device including a case, a semiconductor laser is bonded to a semiconductor laser bonding marker provided at a predetermined position of the framed substrate, and then a step is formed at a predetermined position of the framed substrate. An optical fiber previously fixed in a stepped cylindrical ferrule is installed and fixed in the groove, a cap is attached so as to cover the framed substrate, and then a storage case is attached.

In the semiconductor optical coupling device, the material of the stepped cylindrical ferrule is zirconia, alumina, borosilicate glass, and the stepped cylindrical ferrule is formed in two or more steps.

Further, according to the present invention, in the above-mentioned semiconductor optical coupling device, an optical fiber is inserted and fixed over the entire length of the stepped cylindrical ferrule, and both end faces of the ferrule are spherically polished or obliquely polished.

Further, according to the present invention, in the above-mentioned semiconductor optical coupling device, one of the end faces of the ferrule is spherically polished so that it can be closely joined to an external connector.

Further, according to the present invention, in the semiconductor optical coupling device, the connector guide is attached to the substrate with frame.

Further, according to the present invention, a semiconductor laser, a monitor photodiode, and an optical fiber are mounted on the same substrate, and a frame provided to hold the substrate, and a frame-mounted substrate are attached so as to be housed. In a semiconductor optical coupling device including a case, a semiconductor laser is aligned and bonded to a semiconductor laser bonding marker provided at a predetermined position on the substrate, and then a frame is fixed to the substrate and formed at a predetermined position. Install and fix the optical fiber that was previously fixed in the stepped cylindrical ferrule in the stepped groove that was set, cap it so as to cover the semiconductor laser of the framed substrate, and then assemble it to attach the storage case It is a thing.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
This will be described with reference to FIG. FIG. 1 is a cross sectional view for explaining a semiconductor optical coupling device using a stepped cylindrical ferrule, and FIG. 2 is a plan view. According to FIG. 1, the semiconductor laser 1 has a Si substrate 2
Align and fix on top. When aligning,
A marker is provided on the upper surface of the semiconductor laser 1 and the Si substrate 2
Align with the marker provided on the surface and join. Although the semiconductor laser 1 emits light from the edge surface, the active layer, which is a light emitting point, is formed near the upper surface by using a photoresist, epitaxial growth of a compound single crystal, and the like, and the dimensional accuracy from the upper surface is high. Since the plate thickness of the compound single crystal of the substrate forming the semiconductor laser 1 varies, when the semiconductor laser 1 is bonded to the Si substrate 2 as usual, the height of the active layer becomes Si.
It is difficult to keep constant from the substrate surface. Therefore, the semiconductor laser 1 is bonded so that the normal upper surface is the lower side so that the active layer is close to the Si substrate.

A V-groove is previously processed on the Si substrate 2 so that the tip of the fiber can be positioned at the light emitting portion of the semiconductor laser 1. As a method of forming the V groove, there is a method of processing using anisotropic etching of Si, or a method of machining only the groove portion. As the material of the Si substrate 2, Si single crystal is inexpensive and suitable, but for example, a method of solidifying and molding Si powder, or a metal powder of Ag having good thermal conductivity, Si powder, and resin is used. A mixed and molded substrate may be used.

Frames 4 are provided on the back and side surfaces of the Si substrate 2. The material of the frame is Fe, mild steel (S
PCC), Fe-50Ni, Fe-29Ni-17C
Metals such as o, Cu and stainless steel, or resins such as vinylenated and polyphenylene sulfide are suitable. As shown in FIG. 2, the frame 4 has a frame 41 extending from the side surface, and is fastened to the external connector case to ensure the connection between the tip of the ferrule 3 and the ferrule tip of the external connector. When the external connector is fastened to the tip of ferrule 3, 1 kg will be attached to ferrule 3.
Although the spring force load of will be received from the external connector,
This load is applied to the side surface of the frame 4, and no load is applied to the V-groove joint portion of the ferrule 3. Therefore, the fixed portion of the ferrule 3 becomes stable, and the semiconductor laser 1
It does not cause optical coupling deterioration with. The external connector is
For example, there are FC, SC and MU type connectors.

Leads 9 are temporarily connected to the frame 4 for power supply connection to the semiconductor laser 1 or the photodiode 6, and after the case 8 is attached, the temporary connection is separated.

The shape of the stepped ferrule 3 is, for example, as shown in FIG.
What is indicated by the outer shape is suitable. In the figure, all have a cylindrical appearance, and (A) is a cylindrical shape divided into a thin diameter and a large diameter. 1.249 ± as a small diameter
0.0005, 0.799 ± 0.0005, and a large diameter of 1.8 ± 0.0005 are suitable. This ferrule has a method in which a thin diameter and a thick diameter are the same and is formed by processing, and a hole or through hole in which the thin diameter can be inserted is provided in advance on the thick diameter side, and the thin diameter is inserted into this hole to form a step. There is a method of forming. As shown in FIG. 2, the ferrule 3 is provided with a through hole into which the optical fiber 7 having an outer diameter of 125 μm or 90 μm is inserted. Suitable fibers to be used are a single mode fiber with a core diameter of 10 μm, a multimode fiber with a core diameter of 50 μm, and a polarization-maintaining fiber.

FIG. 3B shows a structure in which a groove is provided in the middle portion of the ferrule. For formation, a hole or a through hole into which a small diameter can be inserted is provided on the large diameter side, and the large diameter is inserted into both ends of a thin ferrule, or the central portion of the same single material is processed to form a step. Further, (C) has a shape of a ferrule having three stages of small, medium, and large. (D) shows the three stages of (C) formed in the order of small, large, and middle. The three-stage forming method is basically the same as (A). Stepped ferrule 3 of FIG.
The end face 3b of the stepped ferrule 3 is slanted by at least 4 degrees or 8 degrees with respect to a right angle, and the end face 3c of the stepped ferrule 3 is 60 degrees.
mm surface is polished to prevent end face reflection at the light incident end or the light emitting end. Suitable materials for the stepped ferrule 3 are zirconia, alumina, and borosilicate glass.

On the side surface of the frame 4, as shown in FIG. 2, a through hole is provided in advance so that the stepped ferrule 3 can be inserted. Therefore, the stepped ferrule 3 is bonded to the V groove 2 a of the Si substrate 2 through the frame 4. The side surface 3a of the stepped ferrule 3 is fixed so as to be in close contact with the side surface of the frame 4.

The oscillated light from the semiconductor laser 1 also enters the photodiode 6 provided on the back surface of the semiconductor laser 1 at the same time as it enters the optical fiber incorporated in the ferrule. By monitoring the incident light of the photodiode 6, the output on the fiber side is always constant,
The current of the semiconductor laser 1 is controlled.

The semiconductor laser 1 or the photodiode 6 may have a shortened life due to the influence of humidity and temperature in the atmosphere. Therefore, the cap 5 or the case 8 is provided to prevent them. The material of the cap 5 is
Borosilicate glass, BK-7, TAF-3, Kovar glass, Fe-29Ni-17Co, Fe-50Ni, S
i is suitable. The case 8 is a method of covering with an epoxy resin mold as in the case of IC resin molding, or a method of forming only a thin case with epoxy resin mold and filling the gap between the cap and the case with resin. There is.

The semiconductor optical coupling device is assembled as follows. A marker for joining the fiber fixing V groove and the semiconductor laser 1 is formed in advance on the Si substrate 2. First, the semiconductor laser 1 is bonded using a marker. The bonding material is A
u-Sn solder is suitable. Au, S on the Si substrate 2
A sputtered film of n is formed by controlling the film thickness, and the semiconductor laser 1 is bonded and fixed on this. The frame 4 is bonded to the back and side surfaces of the Si substrate 2. As the bonding material, for example, an epoxy adhesive material is used. The stepped ferrule 3 is incorporated in the V groove of the Si substrate 2. An epoxy adhesive or a UV adhesive is suitable as the adhesive. Lead 9 on frame 4
Are already temporarily fixed, and the leads 9 are wire-bonded to the semiconductor laser 1 and the photodiode 6.

A cap 5 covering the tip of the semiconductor laser 1, the photodiode 6, and the ferrule 3 is attached. When the mounting position of the cap 5 is on the Si substrate 2, a UV adhesive or an epoxy adhesive is preferable, and in the case of bonding on the frame 4, resistance welding, YAG welding, or soldering is suitable with a metal cap. After the cap 5 is joined, for example, a thin case made of resin mold is attached, and the gap between the cap and the case is filled with silicone resin or chip coat resin.

According to this embodiment, the fiber is previously fixed in the stepped ferrule, fixed to the Si substrate with frame, and can be fastened to the external connector. According to this structure, the fiber is fixed in the ferrule, the fiber strand is not scratched when the semiconductor optical coupling device is assembled, the fiber is not protruding into the device, and the device can be easily transported. It can be assembled in a short time and can be automated. Also, when connecting the external connector,
Even if the ferrule is fixed to the V-groove at a constant load of 1 kg, the stepped ferrule prevents the 1-kg load from being directly applied to the V-groove fixing part, so that the fixing part will stabilize the light. Binding stability can be obtained.

[0029]

According to the present invention, by completely fixing a fiber in a ferrule, the fiber can be assembled easily and in a short time without being damaged by the external moisture when the fiber is assembled in the semiconductor optical coupling device. Yield goes up.
In addition, by adopting the stepped ferrule, the stability of the fixed part of the ferrule with an optical fiber in the V groove of the Si substrate is improved, and even if an external force is applied to the ferrule, the optical coupling is not deteriorated and the ferrule is reliable. Can be fixed. Of course, by incorporating resin fixing in the assembly and using a resin molding material for the case, it is possible to assemble with high productivity at a low price. Also, by incorporating a semiconductor laser and a photodiode in the cap and case,
It is not affected by atmospheric humidity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment of the present invention.

FIG. 2 is a plan view of one embodiment of the present invention.

FIG. 3 is a front view of a stepped ferrule according to an embodiment.

[Explanation of symbols]

1 ... Semiconductor laser, 2 ... Si substrate, 3 ... Stepped ferrule, 4 ... Frame, 5 ... Cap, 6 ... Photodiode, 7 ... Fiber, 8 ... Case.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoichi Takahashi 5-20-1, Kamisuihonmachi, Kodaira-shi, Tokyo Hitachi, Ltd. Semiconductor Division

Claims (10)

[Claims] 1. A semiconductor optical coupling device comprising a case in which a semiconductor laser, a monitor photodiode, and an optical fiber are mounted on the same substrate, and the substrate is mounted so as to be housed therein. After fixing in a ferrule, the optical axis of the light emitted from the semiconductor laser bonded to the same substrate is adjusted, and a fiber with a cylindrical ferrule is bonded and fixed onto the substrate. 2. A semiconductor optical coupling device comprising a case in which a semiconductor laser, a monitoring photodiode, and an optical fiber are mounted on the same substrate, and the substrate is attached so as to be housed therein. After fixing in the ferrule, the optical axis of the light emitted from the semiconductor laser bonded to the same substrate is adjusted, and the fiber with the cylindrical ferrule is bonded and fixed to the stepped groove formed at the predetermined position on the substrate. Semiconductor optical coupling device. 3. A semiconductor optical coupling device comprising a case in which a semiconductor laser, a monitoring photodiode, and an optical fiber are mounted on the same substrate, and the substrate is mounted so as to be housed in the semiconductor optical coupling device. The semiconductor laser was bonded to the semiconductor laser bonding marker, and then the optical fiber previously fixed in the stepped cylindrical ferrule was fixed to the stepped groove formed at the predetermined position of the substrate. A characteristic semiconductor optical coupling device. 4. A semiconductor laser, a monitor photodiode, and an optical fiber are mounted on the same substrate, and a frame is provided to hold the substrate, and a case is attached to house the substrate with the frame. In a semiconductor optical coupling device, a semiconductor laser is bonded to a semiconductor laser bonding marker provided at a predetermined position of the framed substrate, and then, in a stepped groove formed at a predetermined position of the framed substrate, in advance. A semiconductor optical coupling device characterized in that an optical fiber fixed in a stepped cylindrical ferrule is installed and fixed. 5. A semiconductor laser, a monitor photodiode, and an optical fiber are mounted on the same substrate, and a frame is provided to hold the substrate, and a case is attached to accommodate the substrate with the frame. In a semiconductor optical coupling device, a semiconductor laser is bonded to a semiconductor laser bonding marker provided at a predetermined position of the framed substrate, and then, in a stepped groove formed at a predetermined position of the framed substrate, in advance. A semiconductor optical coupling device, comprising: mounting and fixing an optical fiber fixed in a stepped cylindrical ferrule, attaching a cap so as to cover the framed substrate, and then attaching a storage case. 6. The method of claim 1, 2, 3, 4, or 5,
A semiconductor optical coupling device in which the material of the stepped cylindrical ferrule is zirconia, alumina, borosilicate glass, and the stepped cylindrical ferrule is formed in two or more steps. 7. A semiconductor according to claim 1, 2, 3, 4, 5 or 6, wherein an optical fiber is inserted and fixed over the entire length of the stepped cylindrical ferrule, and both end faces of the ferrule are spherically polished or obliquely polished. Optical coupling device. 8. A semiconductor optical coupling device according to claim 1, 2, 3, 4, 5, 6 or 7, wherein one of the end faces of said ferrule is spherically polished so that it can be closely joined to an external connector. 9. A semiconductor optical coupling device according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein a connector guide is attached to the framed substrate. 10. A semiconductor laser, a monitor photodiode, and an optical fiber are mounted on the same substrate, and the frame is provided so as to hold the substrate, and a case is attached so as to house the substrate with the frame. In a semiconductor optical coupling device, a semiconductor laser is aligned with a semiconductor laser bonding marker provided at a predetermined position on the substrate, bonded, and then a frame is fixed to the substrate and formed at a predetermined position. The optical fiber previously fixed in the stepped cylindrical ferrule was set and fixed in the stepped groove, and the storage case was attached after capping the semiconductor laser on the framed substrate. Method for assembling semiconductor optical coupling device.