JP2001183554A - Method of manufacturing optical module, and optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method of manufacturing a semiconductor laser module which is excellent in mass productivity and is high in yield since transfer molding is usable. SOLUTION: An LD 1 is fixed to an Si substrate 3 and 3 the Si substrate 3 is fixed to a frame 6. A ferrule 7 is previously covered by a heat shrinkable tube 10. An optical fiber 4 is arranged on the Si substrate 3 and its one end is coupled to the LD 1 and another end is adhered to the end of the ferrule 7 and is fixed together with the ferrule 7 to the frame 6. The optical waveguide between the LD 1 and a monitor PD 2 and the optical fiber 4 is partially molded with a transparent resin 25 and the entire of the cavity of metal molds 40 and 41 is sealed from above the transparent resin with a molding resin 30 of the transfer molds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical module, and more particularly to a method for manufacturing an optical module integrally including an optical fiber by transfer molding and an optical module manufactured by the transfer molding. is there.

[0002]

2. Description of the Related Art In the near future, as information transmission from homes to personal computers as terminals increases, telephone lines for subscribers, which are communication circuits for handling large amounts of data, need to be replaced by electric cables instead of electric wires. . The transceiver for optical communication for subscribers needs an inexpensive and small optical module with fiber. By the way, in the optical module with a fiber, it is necessary to make the laser emitted from the semiconductor laser efficiently enter the optical fiber.

FIG. 7 is a partially cutaway perspective view of a semiconductor laser module, which is an inexpensive and compact optical module with a fiber which will be required in the future. In the figure, 1 is a semiconductor laser diode (LD), 2 is a monitor photodiode (monitor PD), 3 is a Si substrate, 4 is an optical fiber, 5 is a bonding wire, 6 is a frame, 7 is a ferrule, and 8 is V
The groove, 9 is a connector locking portion, 20 is an external lead, and 30 is a mold resin.

In the above-described conventional semiconductor laser module, as shown in FIG. 7, a semiconductor laser diode (LD) 1 is fixed on a silicon (Si) substrate 3 and an output (emission light) from one emission end face of the LD 1 is provided. ), A monitoring photodiode (monitor PD) 2 is arranged near the LD 1, an optical fiber 4 is arranged near the other emission end face of the LD 1, and a V-groove provided on the Si substrate 3. 8 is fitted. One end of the bonding wire 5 is connected to the electrodes of the monitor PD2 and the LD1, and the other end is connected to the external lead 20. The Si substrate 3 and the monitor PD2 are fixed to a frame 6 made of an FeNi alloy, and a connector locking portion 9 is formed at a rear end thereof. The ferrule 7 made of zirconia or the like serves as an optical output terminal of a connector portion of the semiconductor laser module, and the optical fiber 4 is connected to the tip thereof.

One example of assembling the semiconductor laser diode 1 into a module as shown in FIG. 7 is shown below. FIG.
As shown in (1), the LD 1 is fixed to the Si substrate 3, and the Si substrate 3 is fixed to the FeNi alloy frame 6 and assembled.
The optical fiber 4 is arranged in the V groove 8 on the Si substrate 3, one end of which is connected to the LD 1, and the other end is bonded to the end of the ferrule 7 with an epoxy-based adhesive or the like, and is connected to the ferrule 7. Then, the optical fiber 4 together with the ferrule 7 is connected to the frame 6
Fixed to. Next, after partially molding the optical waveguide path between the LD 1 and the monitor PD 2 and the optical fiber 4 with a transparent resin, the whole including the external leads 20 is covered with a molding resin 30 by transfer molding. The size of the semiconductor module assembled as described above is 10 m
It is about mx13mmx5mm. In FIG. 7, the monitor PD2 is disposed so as to face slightly obliquely with respect to the LD1, but this prevents light incident on the monitor PD2 from being reflected and entering the LD1 again to generate noise or the like. This is for the purpose of preventing.

[0006]

However, as described above, in the method of manufacturing an optical module such as a semiconductor laser module using the transfer molding method,
Since a mold that can be divided in the up-down direction is used, in order to prevent resin leakage from the cavity, it is necessary to clamp without a gap with a high pressure of 2 to 20 MPa including the ferrule part made of ceramic. The temperature of the mold at this time needs to be as high as 130 to 200 ° C. in order to lower the resin viscosity during transfer molding. For this reason, when the mounting position accuracy of the ferrule is poor, defects such as breakage of the ferrule due to contact pressure with the mold, resin leakage from around the ferrule, or protrusion of the ferrule are likely to occur. Therefore, in a method of manufacturing an optical module such as a semiconductor laser module by transfer molding as in the above-described conventional case, the yield is low,
The mass productivity, which is an advantage of the transfer molding method, could not be utilized, and the cost could not be reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a method of manufacturing an optical module which is excellent in mass productivity and has a high yield since transfer molding can be used, and an optical module manufactured by the method. The purpose is to obtain.

[0008]

According to a first method of manufacturing an optical module according to the present invention, a step of mounting a semiconductor laser diode on a substrate, a step of fixing a substrate and a frame, and a step of connecting one end of an optical fiber to the semiconductor The step of optically coupling the laser diode and the other end to the ferrule, the step of placing the ferrule on the frame, and the upper and lower molds for molding having a cavity covering the substrate, the lead frame. And a part of the ferrule, in a method of manufacturing an optical module including a step of molding a package by injecting resin for molding into the cavity, before the step of molding the package,
This is a method of inserting a ferrule into a heat-shrinkable tube and then subjecting the tube to a ferrule by heat treatment.

A second method for manufacturing an optical module according to the present invention is a method for manufacturing a first optical module, wherein the ferrule is covered with a metal protective material.

A third method for manufacturing an optical module according to the present invention is the method for manufacturing the first or second optical module, wherein the thickness of the heat-shrinkable tube is 5% to 200% of the outer diameter of the ferrule. Is the way.

According to a fourth aspect of the present invention, there is provided the optical module according to any one of the first to third aspects, wherein the elastic modulus of the heat-shrinkable tube is 10E4.
-10E9Pa.

A first optical module according to the present invention is manufactured by any one of the first to fourth optical module manufacturing methods.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is an external view of a semiconductor laser module as an optical module according to a first embodiment of the present invention. FIG. 2 is a partially cutaway perspective view of the semiconductor laser module. LD), 2 a monitor photodiode (monitor PD), 3 a Si substrate, 4 an optical fiber, 5 a bonding wire, 6 a frame, 7 a ferrule, 8 a V
Groove, 9 is a connector locking portion, 10 is a heat-shrinkable tube, 20
Is an external lead, and 30 is a mold resin.

In the semiconductor laser module, as shown in FIGS. 1 and 2, an LD 1 is fixed on a silicon (Si) substrate 3 and a monitor for monitoring an output (emitted light) from one emission end face of the LD 1. A photodiode (monitor PD) 2 is disposed near the LD 1 and the LD 1
The optical fiber 4 is arranged near the other emission end face of the substrate 3 and is fitted in the V groove 8 provided in the Si substrate 3. One end of the bonding wire 5 is connected to the electrodes of the monitor PD 2 and the LD 1, and the other end is connected to the external lead 2.
0 is connected. The Si substrate 3 and the monitor PD2 are fixed to a frame 6 made of an FeNi alloy, and a connector locking portion 9 is formed at a rear end thereof. The ferrule 7 made of zirconia or the like serves as an optical output terminal of a connector portion of the semiconductor laser module, and the optical fiber 4 is connected to the tip thereof. The optical waveguide path between the LD1, the monitor PD2 and the optical fiber 4 is partially molded with a transparent resin in order to prevent the mold resin 30 from entering. The ferrule was previously inserted into the heat-shrinkable tube, and the heat-shrinkable tube was brought into close contact by heat treatment.

The heat-shrinkable tube 10 according to the embodiment of the present invention includes, for example, fluorine rubber, silicone rubber, polyolefin, polyester, vinyl chloride, polytetrafluoroethylene (PTFE), and tetrafluoroethylene / ethylene copolymer ( A heat-shrinkable tube made of synthetic rubber or synthetic resin such as ETFE), tetrafluoroethylene / perfluoroalkylvinyl ether copolymer (PFA), or tetrafluoroethylene / hexafluoropropylene copolymer (FEP); For example, ST-D @ product name: Shin-Etsu Chemical Co., Ltd.
｝, EIT-F ｛Product name: GUNZE Co., Ltd.｝ or Sumitube KH230 ｛Product name: Sumitomo Electric Co., Ltd.
Manufacturing is used.

As a method for coating the heat-shrinkable tube 10, a heat-shrinkable tube whose inner diameter before heat-shrinkage is larger than the outer diameter of the ferrule 7 is selected and cut into a predetermined length.
Put on ferrule 7 and at a temperature of 80 to 250 ° C,
Heat treatment is performed for about 5 seconds to 30 minutes. This heat treatment may be performed in an oven, or a dryer or the like may be used. The coating of the heat shrinkable tube 10 on the ferrule 7 can be appropriately performed before molding with a resin in the following manufacturing method.
And the ferrule 7 are bonded by an epoxy adhesive or the like to perform optical coupling.

The thickness of the heat-shrinkable tube is preferably 5% to 200% of the outer diameter of the ferrule. If the wall thickness is less than 5% of the outer diameter of the ferrule, the effect of the ferrule as a cushioning material may not be observed when the mounting accuracy of the ferrule is low. Is large, but the thermal expansion coefficient of the heat-shrinkable tube is large, so the adhesion to the mold resin interface after molding may decrease, and the product reliability decreases, such as when excessive thermal stress is applied to the module There are cases. The elastic modulus of the heat shrink tube is 10
E4 to 10E9 Pa is desirable, and the elastic modulus is
If it exceeds 10E9 Pa, the effect of ferrule protection may not be seen because it is too rigid. On the other hand, when the elastic modulus is 10
When it is smaller than E4Pa, the effect as a buffer material is high, but the resin is too soft, and resin leakage may occur due to resin flow pressure at the time of resin injection.

Hereinafter, a method for manufacturing the semiconductor laser module will be described. That is, as shown in FIG.
The Si substrate 3 is fixed to the substrate 3 and fixed to the FeNi alloy frame 6 for assembly. The ferrule 7 is previously coated with the heat-shrinkable tube 10 as described above, and the optical fiber 4 is arranged in the V-groove 8 on the Si substrate 3, one end of which is connected to the LD 1, and the other end is the ferrule. The optical fiber 4 is fixed to the frame 6 together with the ferrule 7 by gluing it to the end of the substrate 7 with an epoxy adhesive or the like to manufacture a subassembly. The subassembly assembled as described above is used to prevent the non-transparent molding resin 30 from entering the optical waveguide path between the LD 1 and the monitor PD 2 and the optical fiber 4 during the transfer molding. Is partially molded with a transparent resin.

Next, the entire cavity of the mold is sealed with the transfer molding resin 30 from above the transparent resin. FIG. 3 is an explanatory view showing a state of transfer molding in a method of manufacturing a semiconductor laser module as an optical module according to the first embodiment of the present invention. In FIG. And 40 and 41 are an upper mold and a lower mold, respectively. In FIG. 3, the subassembly includes a lead frame 6.
The ferrule 7 is clamped via the heat-shrinkable tube 10 in a state clamped between the upper mold and the lower mold 40, 41, and is injected into a cavity, which is a space between the molds 40, 41, by a resin. Mold. Heat shrink tube 1
0 prevents the ferrule from being broken due to stress caused by contact between the mold and the ferrule, and since the molds 40 and 41 and the heat-shrinkable tube 10 are in close contact with each other, the resin in the cavity does not leak to the outside during clamping. It is intended to prevent resin leakage from around the ferrule due to poor position accuracy. In addition, when the heat shrink tube is used as described above,
The process of coating the ferrule is simpler than in the past, and a semiconductor laser module can be manufactured in a short time and at low cost.

Embodiment 2 FIG. 4 is an external view of a semiconductor laser module as an optical module according to a second embodiment of the present invention, FIG. 5 is a partially cutaway perspective view of the semiconductor laser module, and FIG. 6 is a second embodiment of the present invention. It is an explanatory view showing a state of the transfer mold in the method of manufacturing a semiconductor laser module as an optical module of,
In the figure, reference numeral 11 denotes a metal protective material such as a SUS pipe provided on the ferrule 7. That is, in the first embodiment,
When a semiconductor laser module is manufactured by transfer molding, a cylindrical metal protective material 11 is provided on a clamp portion of a ferrule 7. Conventionally, when the protective material 11 is provided on the clamp portion of the ferrule 7, it is effective in preventing the ferrule from breaking. However, there is a problem that the optical coupling shift is likely to occur due to the strain applied to the metal protective material. In the present embodiment, as shown in FIGS.
By covering the periphery of the metal protective material 11 with the heat-shrinkable tube 10 and clamping it with the molds 40 and 41, it is possible to prevent the ferrule from being broken at the time of transfer molding and to prevent the optical coupling shift. can do.

In the above-described embodiment, the case where a semiconductor laser module is manufactured as an optical module has been described. However, also when an optical module for receiving or transmitting is manufactured by transfer molding,
As in the present invention, the same effect as in the present invention can be obtained by closely attaching the heat-shrinkable tube to the ferrule. In each of the above embodiments, molding conditions such as a mold temperature, a mold clamping force, a resin material, or a molding pressure during molding can be arbitrarily selected within a range where normal transfer molding can be performed. Further, in the above-described embodiment, an example in which the semiconductor laser module is formed in a single unit has been described. However, the above-described manufacturing method can be easily applied to manufacturing in which a large number of semiconductor laser modules are simultaneously formed using a multi-row lead frame. Furthermore, it is also possible to manufacture a package by injection molding using a thermoplastic resin instead of a thermosetting resin.

[0022]

According to the first method of manufacturing an optical module of the present invention, a step of mounting a semiconductor laser diode on a substrate, a step of fixing a substrate and a frame, and optically coupling one end of an optical fiber to the semiconductor laser diode. A step of optically coupling the other end to the ferrule, a step of placing the ferrule on the frame, and a part of the lead frame and the ferrule by an upper mold and a lower mold for a mold having a cavity covering the substrate. In a method for manufacturing an optical module comprising a step of molding a package by injecting molding resin into the cavity, inserting a ferrule into a heat-shrinkable tube before the step of molding the package. In a method in which the above tube is brought into close contact with the ferrule by heat treatment, transfer molding may be used. Excellent in mass production because the kill, and the yield is there is an effect that high.

The second method for manufacturing an optical module according to the present invention is the same as the first method for manufacturing an optical module, except that the ferrule is covered with a metal protective material.

According to a third optical module manufacturing method of the present invention, in the above-mentioned first or second optical module manufacturing method, the thickness of the heat-shrinkable tube is five times the outer diameter of the ferrule.
% To 200%, there is an effect that the yield is further increased.

According to a fourth aspect of the present invention, there is provided the optical module according to any one of the first to third aspects, wherein the elastic modulus of the heat-shrinkable tube is from 10E4 to 10E4.
The method of 10E9Pa has an effect of further increasing the yield.

The first optical module according to the present invention includes the first optical module.
The optical module is manufactured by any one of the optical module manufacturing methods according to any one of the fourth to fourth aspects, and has an effect that characteristics are improved and reliability is improved.

[Brief description of the drawings]

FIG. 1 is an external view of a semiconductor laser module as an optical module according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of a semiconductor laser module as an optical module according to the first embodiment of the present invention.

FIG. 3 is an explanatory view showing a state of a transfer mold in a method for manufacturing a semiconductor laser module as an optical module according to the first embodiment of the present invention.

FIG. 4 is an external view of a semiconductor laser module as an optical module according to a second embodiment of the present invention.

FIG. 5 is a partially cutaway perspective view of a semiconductor laser module as an optical module according to a second embodiment of the present invention.

FIG. 6 is an explanatory view showing a state of a transfer mold in a method for manufacturing a semiconductor laser module as an optical module according to a second embodiment of the present invention.

FIG. 7 is a partially cutaway perspective view of a conventional semiconductor laser module.

[Explanation of symbols]

Reference Signs List 1 semiconductor laser diode (LD), 2 monitor photodiode (monitor PD), 3 substrate, 4 optical fiber, 6 frame, 7 ferrule, 10 heat shrink tube, 30 mold resin, 11 metal protective material, 25
Transparent resin, 40 upper mold, 41 lower mold.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2H037 AA01 BA04 DA03 DA04 DA06 DA12 DA15 DA17 DA36 DA39 5F073 AB15 AB28 BA02 FA02 FA07 FA29

Claims (5)

[Claims] A step of mounting a semiconductor laser diode on a substrate, a step of fixing the substrate to a frame, a step of optically coupling one end of an optical fiber to the semiconductor laser diode, and a step of optically coupling the other end to a ferrule. The step of placing the above on the frame, and the upper mold and lower mold for the mold having a cavity covering the substrate,
In a method for manufacturing an optical module including a step of molding a package by injecting a molding resin into the cavity and sandwiching a part of the lead frame and a ferrule, a ferrule is formed before the step of molding the package. A method for manufacturing an optical module, comprising: inserting a heat-shrinkable tube into a heat-shrinkable tube; 2. The method for manufacturing an optical module according to claim 1, wherein the ferrule is covered with a metal protective material. 3. The heat-shrinkable tube according to claim 1, wherein the thickness of the heat-shrinkable tube is 5% to 200% of the outer diameter of the ferrule.
A method for manufacturing an optical module according to claim 2. 4. The heat-shrinkable tube has an elastic modulus of 10E4-1.
4. The method for manufacturing an optical module according to claim 1, wherein the pressure is 0E9 Pa. 5. 5. An optical module manufactured by the manufacturing method according to claim 1.