JPH07113931A - Semiconductor laser module and its production - Google Patents

Abstract

PURPOSE:To discretely assure a hermetic sealing state and to suppress the light output deterioration affected by stress at the time of packaging to a lower level. CONSTITUTION:This semiconductor module has a metallic case 10 formed with a through-hole 10a slightly larger than the front end of an optical isolator 12 on its wall surface. A metallic base 4 mounted with a semiconductor laser 1, a condenser lens 6, etc., is mounted via a Peltier element 11 within the metallic case 10. The front end of the optical isolator 12 and the through-hole 10a of the metallic case 10 are tightly fixed by solder 13. Further, the opening of the metallic case 10 is soldered and sealed by a metallic cap 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser module having a metal housing in which a part of an optical path of a semiconductor laser is hermetically shielded, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Since optical fiber communication, which is hardly affected by electromagnetic induction and is capable of long-distance transmission with low loss, has been put into practical use,
Various efforts have been made to increase the transmission distance and the transmission capacity, and the performance of semiconductor light emitting devices and light receiving devices has been improved, and the mounting method of individual devices has been studied and improved. Especially for semiconductor lasers that have a complicated element structure and are easily affected by the environment, a temperature adjustment element is built into the semiconductor laser module or the reflected light from the outside of the semiconductor laser module is used for the purpose of always operating at a constant temperature. For the purpose of eliminating the above problem and enabling stable operation of the semiconductor laser, various measures have been taken such as incorporating an optical isolator. As an example of such a semiconductor laser module, Japanese Patent Laid-Open No. 3-6
There is one disclosed in Japanese Patent No. 8915.

3A and 3B are views showing the structure of an example of a conventional semiconductor module. FIG. 3A is a top view and FIG. 3B is a side view.

As shown in FIG. 3, a semiconductor laser 31 is mounted on a semiconductor laser carrier 33 via a heat sink 32. The semiconductor laser carrier 33 has a photodiode 34 and a base 34 to which a condenser lens 37 is fixed.
The optical isolator 131 is fixed to the base 34 by soldering.
Further, the optical fiber 135 is optically adjusted and fixed to the optical isolator 131 via the ferrule 39 and the slide ring 38. Further, the base 34 is fixed to the metal case 132 via the Peltier element 133 and protects the optical fiber 135 from the ferrule 3.
9 is the solder 13 in the optical fiber introduction hole of the case 132.
Fixed at 4. After that, the semiconductor laser module has the leads 136 protruding outside the case 132 and the case 132.
After electrical continuity is achieved by using wiring by a bonding wire inside, a metal lid (not shown) is sealed and fixed in the opening of the metal case 132, and the case 132 is hermetically sealed to complete.

In this way, the semiconductor laser module not only enables the semiconductor laser module to operate at a constant temperature by the Peltier element 133, and also eliminates the influence of reflected return light due to the built-in optical isolator 131, and enables stable operation of the semiconductor laser. Since the semiconductor laser device can be directly connected to the lead 136 outside the case 132 by bonding, parasitic capacitance and inductance can be minimized, and the whole case can be easily grounded so that the semiconductor laser module itself operates at high speed. It has a structure suitable for making it.

[0006]

Originally [0005], the semiconductor laser monitor output photodetector elements there sometimes are subjected to reflection film coating, airtightness of the retained (leak level ≦ 10 ^{over 8} atm · cc / sec ) It is desirable to be used in the state. However, in the above-mentioned conventional semiconductor laser module, in order to realize the complete airtight sealing in the case, it is necessary to provide the airtight shielding portion inside the ferrule protecting the optical fiber by using a sealing method such as solder sealing. . This is because the optical fiber itself does not function as an airtight shield, but it is extremely difficult to realize a structure in which the airtight shield is provided inside the metal ferrule, and the airtight sealing of the completed semiconductor laser module is individually performed. In order to guarantee it, it is necessary to ensure airtightness with a solder seal at the optical fiber introduction port of the case to perform a leak check, and there is a problem that individual guarantee is difficult in practical use.

Further, when the completed semiconductor laser module is mounted on a substrate or the like and used, stress may be applied to the case due to mounting, and this stress is applied to the ferrule through the solder in the optical fiber introducing hole of the case. Then, a minute shift of about 2 to 3 μm is given to the positional relationship among the semiconductor laser, the condenser lens, the optical isolator, and the optical fiber. In the example of the semiconductor laser module shown as the prior art, the position where the stress is applied may be far from the semiconductor laser which can be assumed to be a point light source, so that a minute change in the positional relationship is caused by the optical output from the optical fiber and the optical output deteriorates by 0.5 dB or more. Had a problem of causing.

The present invention provides a semiconductor laser module capable of individually guaranteeing a hermetically sealed state in a case and suppressing deterioration of optical output affected by stress during mounting to a small extent, and a method of manufacturing the same. The purpose is to

[0009]

According to the present invention for achieving the above object, a semiconductor laser and a condenser lens for mounting the semiconductor laser and condensing output light from the semiconductor laser are closely fixed. A metal base, the semiconductor laser is built-in, a metal case in which a through hole for passing the output light from the semiconductor laser is formed in the side wall, and a metal lid for hermetically sealing the metal case, In a semiconductor laser module including an optical fiber, a metal housing portion fixed to the metal base and hermetically shielding a part of an optical path of the semiconductor laser focused by the focusing lens is used. One in which the through hole of the case is sealed with the metal housing by soldering, or one in which an optical isolator is used as the metal housing may be used. A method of manufacturing a laser module, comprising: fixing a semiconductor laser carrier carrying the semiconductor laser to a metal base by soldering, fixing an optical isolator to the metal base, the metal base and a bottom surface in the metal case, the optical isolator. And the through holes of the metal case are fixed by soldering respectively, and the semiconductor laser is electrically connected to the wiring pattern in the metal case which is electrically connected to the lead wire outside the metal case by using a bonding wire, and the metal case and the metal are further connected. After the lid is sealed to form a completely airtight case, an optical fiber is fixed to the optical isolator for manufacturing.

Further, a semiconductor laser, a metal base on which the semiconductor laser is mounted and a condenser lens for condensing the output light from the semiconductor laser is closely fixed, the semiconductor laser is built in, and the side wall is provided with the semiconductor laser. In a semiconductor laser module including a metal case having a through hole for allowing output light from a semiconductor laser to pass through, a metal lid for hermetically sealing the metal case, and an optical fiber, The through hole may be sealed with the metal base by solder, which is a method of manufacturing the semiconductor laser module, wherein the semiconductor laser carrier carrying the semiconductor laser is fixed to the metal base by soldering, The metal base is fixed by soldering on the bottom surface and the through hole of the metal case, and the bonding wire is used to attach the metal base The semiconductor laser is electrically connected to the wiring pattern in the metal case which is electrically connected to the lead wire, and the metal case and the metal lid are further sealed to form a completely airtight case, and then the optical fiber is fixed to the metal base. It is characterized by being manufactured by

[0011]

In the present invention configured as described above, the metal base on which the semiconductor laser is mounted and the condensing lens for condensing the output light from the semiconductor laser is closely fixed, is mounted on the wall surface from the semiconductor laser. A metal housing part that is fixed in a metal case having a through hole for allowing output light to pass therethrough, and that hermetically shields a part of the optical path of the semiconductor laser focused on the metal base by the focusing lens. Is fixed, and the through-hole of the metal case is sealed with the metal housing and solder, and then the metal case itself is solder-sealed with a metal lid, so that the inside of the metal case in which the semiconductor laser is built is complete. It becomes an airtightly sealed state. That is,
Instead of sealing the through hole of the metal case with an optical fiber that does not function as an airtight shield, a metal case before mounting the optical fiber is used by sealing a part of the optical path of the semiconductor laser with a metal case that hermetically shields. The hermetically sealed state inside is individually guaranteed.

Further, since the optical structure in which a semiconductor laser, which can be assumed to be a point light source, and an optical fiber are coupled in series, is supported at a position closer to the semiconductor laser than in the conventional case, stress that may occur due to case mounting is The small displacement of the optical system that causes it becomes small.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a structural diagram showing an embodiment of a semiconductor laser module of the present invention.

As shown in FIG. 1, the semiconductor laser 1 is mounted on the metal base 4 together with the photodiode 5 for monitoring via the heat sink 2 and the semiconductor laser carrier 3 as in the prior art. A condenser lens 6 is closely fixed to the metal base 4, and an optical isolator 12 is fixed to the tip of the metal base 4. Further, an optical fiber 8 protected by a ferrule 7 is fixed to the tip of the optical isolator 12 via a slide ring 9. The output light from the semiconductor laser 1 is guided to the optical fiber 8 by the series of couplings, and the optical isolator 12 hermetically seals a part of the optical path of the semiconductor laser 1 condensed by the condenser lens 6. It is a shielded metal housing.

The semiconductor laser module of this embodiment is provided with a metal case 10 having a through hole 10a formed in the wall surface, which is slightly larger than the tip of the optical isolator 12. Then, the metal base 4 is mounted inside the metal case 10 via a Peltier element 11, and the tip end portion of the optical isolator 12 and the through hole 1 of the metal case 10 are attached.
And 0a are closely fixed by solder 13. Furthermore, the opening of the metal case 10 is sealed with a metal lid 14 by soldering.

Next, the manufacturing process of this embodiment will be described with reference to FIGS.

FIG. 2 is a flow chart for explaining the manufacturing process of one embodiment of the semiconductor laser module of the present invention.

As shown in FIGS. 1 and 2, the semiconductor laser 1 is mounted on a heat sink 2 and
After being mounted on the semiconductor laser carrier 3, the semiconductor laser carrier 3 is soldered and fixed to the metal base 4 having the condenser lens 6 together with the photodiode 5. After the optical isolator 12 is fixed to the metal base 4, it is soldered and fixed to the metal case 10 via the Peltier element 11, and the through hole 10a of the metal case 10 is fixed to the optical isolator 9 by the optical isolator 9.
Solder seal with. The metal case 10 containing the semiconductor laser 1 is hermetically sealed with a metal lid 14 after wiring with a lead wire (not shown) outside the case by a bonding wire. In this way, the metal case 10 hermetically sealed is subjected to a leak check as needed, and the one whose hermetically sealed state is incomplete is removed. As a result, the airtight state of each element is guaranteed, and then the element is optically coupled via the slide ring 9 to the ferrule 7 that protects the optical fiber 8.

Usually, each of the polarizer, the analyzer, and the Faraday rotator of the optical isolator 12 is soldered and fixed to a metal casing for improving reliability, and the optical isolator itself is hermetically shielded by the metal casing. Have Therefore, by fixing the metal case 10 with the optical isolator 12 by soldering, the through hole 10a of the metal case 10 can be hermetically shielded, and after the wiring by the bonding wire, the metal case 14 is soldered to the metal case itself. By sealing, the semiconductor laser module can be completely hermetically sealed.

Further, the stress generated in the metal case 10 at the time of mounting the semiconductor laser module is transmitted to the optical isolator 12 through the solder 113, but the optical isolator itself has a strong structure as a metal casing and the optical coupling changes with respect to the stress. In addition, the distance from the semiconductor laser 1 is relatively shorter than that of the configuration shown in the related art, and therefore the deterioration of the optical output due to the change of the optical coupling can be suppressed to be extremely small (≦ 0.2 dB). it can.

In this embodiment, an example in which the through hole 10a of the metal case 10 is sealed by the optical isolator 12 as a hermetically sealed metal housing is shown. However, the metal base is used without using the optical isolator 12. Obviously, the same effect can be obtained when the device itself is used as an airtight shield.

[0023]

As described above, the semiconductor laser module of the present invention has the metal casing that hermetically shields the optical path of the output light of the semiconductor laser condensed by the condenser lens. It is fixed to the metal base on which the semiconductor laser is mounted, and the through hole of the metal case is sealed with a metal housing by soldering, or the through hole of the metal case is solder sealed with the metal base itself without using the metal housing. By having the structure that is stopped, the bonding wire secures the continuity with the lead wire outside the metal case, and the metal case is sealed with the metal lid, and before the optical fiber is attached, the metal case is completely hermetically sealed (leak level). ≦ 10 ^{over 8} atm · cc / se
Not only can c) be assured individually, but also the small displacement of the optical system of about 2 to 3 μm caused by the stress that can occur due to case mounting is a displacement at a position close to the semiconductor laser that can be assumed to be a point light source. , Suppresses the effect on the optical output from the optical fiber (≦ 0.2 dB)
There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a structural diagram showing an embodiment of a semiconductor laser module of the present invention.

FIG. 2 is a flow chart for explaining a manufacturing process of one embodiment of the semiconductor laser module of the present invention.

3A and 3B are diagrams showing a structure of an example of a conventional semiconductor module, where FIG. 3A is a top view and FIG. 3B is a side view.

[Explanation of symbols]

 1 Semiconductor Laser 2 Heat Sink 3 Semiconductor Laser Carrier 4 Metal Base 5 Photodiode 6 Focusing Lens 7 Ferrule 8 Optical Fiber 9 Slide Lens 10 Metal Case 10a Through Hole 11 Peltier Element 12 Optical Isolator 13 Solder 14 Metal Lid

Claims (5)

[Claims] 1. A semiconductor laser, a metal base on which the semiconductor laser is mounted, and a condensing lens for condensing output light from the semiconductor laser is closely fixed, a semiconductor laser is built in, and a side wall is provided. A metal case in which a through hole for passing the output light from the semiconductor laser is formed, and a metal lid for hermetically sealing the metal case,
A semiconductor laser module including an optical fiber, comprising a metal housing part fixed to the metal base and hermetically shielding a part of an optical path of the semiconductor laser focused by the focusing lens, A semiconductor laser module, wherein a through hole of the case is sealed with the metal housing by solder. 2. The semiconductor laser module according to claim 1, wherein an optical isolator is used as the metal casing. 3. A semiconductor laser, a metal base on which the semiconductor laser is mounted and a condensing lens for condensing output light from the semiconductor laser is closely fixed, the semiconductor laser is built in, and the metal laser is built into the side wall. In a semiconductor laser module including a metal case having a through hole for passing output light from a semiconductor laser, a metal lid for hermetically sealing the metal case, and an optical fiber, the metal case A semiconductor laser module, wherein a through hole is sealed with the metal base by solder. 4. The method of manufacturing a semiconductor laser module according to claim 2, wherein the semiconductor laser carrier having the semiconductor laser mounted thereon is fixed to the metal base by soldering, and the optical isolator is fixed to the metal base. The base and the bottom surface in the metal case, the optical isolator and the through hole of the metal case are fixed by soldering, respectively, and the wiring pattern in the metal case and the semiconductor are electrically connected to the lead wire outside the metal case by using a bonding wire. A method for manufacturing a semiconductor laser module, comprising: connecting a laser, further sealing the metal case and the metal lid to form a completely airtight housing, and then fixing an optical fiber to the optical isolator for manufacturing. . 5. The method of manufacturing a semiconductor laser module according to claim 3, wherein the semiconductor laser carrier having the semiconductor laser mounted thereon is fixed to the metal base by soldering, and the bottom surface in the metal case and the metal case penetrate. The metal base is soldered and fixed by the holes, and the semiconductor laser is electrically connected to the wiring pattern in the metal case which is electrically connected to the lead wire outside the metal case by using a bonding wire, and the metal case and the metal lid are sealed. A method of manufacturing a semiconductor laser module, which comprises: stopping to form a completely airtight case, and then fixing an optical fiber to the metal base to manufacture.