JP2606075B2 - Package structure of semiconductor laser module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package structure of a semiconductor laser module for optical communication, and more particularly to a package structure of a semiconductor laser module which can be surface-mounted on a printed circuit board.

[0002]

2. Description of the Related Art A semiconductor laser module generally comprises an optical fiber, a semiconductor laser for inputting an optical signal to the optical fiber, and a monitoring light receiving element for monitoring an optical signal output from the semiconductor laser. ing.
Here, a photodiode is often used as the monitor light receiving element. Such a semiconductor laser module is disclosed, for example, in JP-A-63-122186 and JP-A-6-122186.
4-32694, JP-A-2-42782,
JP-A-2-97081, JP-A-2-253689
As described in Japanese Unexamined Patent Publication (Kokai) No. H11-216, one semiconductor laser and a photodiode are formed on the same substrate, and one is housed in a package.

FIG. 7 shows a package structure of such a conventional semiconductor laser module. One end of an optical fiber 12 is inserted into one side wall of the rectangular package 11, and a semiconductor laser 13 for emitting an optical signal is fixed at a position inside the package facing the end. A monitoring photodiode 14 is arranged near the semiconductor laser 13 at a position where the signal does not hinder the optical signal from entering the optical fiber 12. The package 11 has lead terminals 15 ₁ , 15 ₂ ,.
… Is planted. These lead terminals 15 ₁ , 15
_2, ... are connected semiconductor laser 13 and the monitor photodiode 14 electrically.

[0004] When a semiconductor laser module is incorporated in a device, it is generally fixed to a printed board by soldering. Conventionally, this fixing work by soldering has been performed manually.

[0005]

As described above, heretofore, the semiconductor laser module has conventionally been manually mounted on the printed circuit board, mainly for the following reasons. The optical fiber 12 itself is easily broken,
Since this was covered with a resin such as nylon having low heat resistance, manual work by a skilled worker was safer. Although the optical axes of the optical fiber 12 and the semiconductor laser 13 need to coincide, the optical axis tends to be shifted due to mechanical or thermal stress, and therefore, great care has to be taken.

As described above, in the conventional package structure of a semiconductor laser module, since the package is to be manually mounted on the printed circuit board, the work cannot be performed efficiently, and the manufacturing cost can be reduced. It was difficult. In addition, there is a problem that a skilled worker is required.

It is an object of the present invention to provide a package structure of a semiconductor laser module which enables automatic mounting on a printed circuit board by an automatic machine and automatic soldering by reflow.

Another object of the present invention is to provide a package structure of a semiconductor laser module which can reduce the size of a device on which the semiconductor laser module is mounted.

[0009]

According to the first aspect of the present invention, there are provided (a) a printed board, and (b) one end of an optical fiber.
For injecting optical signal into one end of optical fiber
The laser and the laser
Some of the light output from the body laser is used as external monitor light.
Opening window for emitting laser light and the semiconductor laser
The lead terminals connected to the
A first pad for soldering the circuit board terminal to a predetermined position on the printed circuit board.
And (c) a light receiver for detecting monitor light therein.
The element is housed and the monitor light is transmitted through the first opening window.
Opening window and light receiving element
Connect the lead terminals for surface mounting by the connected automatic machine to the wall.
Parts, respectively, and the first and second opening windows are
Automatically place on the printed circuit board in an
Motivational surface mounted second package and semi-conductive
The package structure of the body laser module was adopted .

That is, according to the first aspect of the present invention, one end of the optical fiber and a semiconductor laser for inputting an optical signal to the one end of the optical fiber are housed in the first package, and the remaining monitor light is received. The device was housed in a second package. For this purpose, the first and second packages are provided with first or second opening windows for transmitting monitor light. Thus, the second package is that a few constraints on usage Compared to the first package. Therefore, the lead terminals of the second package are automatically
It is used for surface mounting by a machine,
Automatic soldering such as automatic mounting and reflow
You.

[0011]

[0012]

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

FIG. 1 shows a package of a semiconductor laser module according to an embodiment of the present invention mounted on a printed circuit board. A printed board 21 has a surface-mounted IC (integrated circuit) 22 mounted thereon, and a first package 23 and a second package 24 constituting the semiconductor laser module of the present embodiment. First
The optical fiber 25 is connected to the package 23.

FIG. 2 shows the appearance of the first package, and FIG. 3 shows the inside of the first package. Package body 31 of first package 23
An optical fiber 25 is inserted through the inside, and an end of the optical fiber 25 is arranged to face the semiconductor laser 32, and optical axis alignment is performed between the two. Lead terminals 33 ₁ and 33 ₂ are implanted outside the package body 31. These lead terminals 33 ₁ and 33 ₂ are electrically connected to the semiconductor laser 32.

A first glass window 35 is adhered to a wall surface of the package body 31 in which the semiconductor laser 32 is housed, the wall surface facing the wall surface through which the optical fiber 25 is inserted. The side wall covered with the first glass window 35 is hollowed out to form a first opening 36. A part of the laser light emitted from the semiconductor laser 32 is transmitted as monitor light from the first opening 36 through the first glass window 35 toward the second package 24 shown in FIG. It has become.

FIG. 4 shows the appearance of the second package, and FIG. 5 shows the inside of the second package. Package body 41 of second package 24
A monitor photodiode 42 is fixed in the inside, and a side wall facing the monitor photodiode 42 is hollowed out in a circular shape to receive monitor light, and forms a second opening 43. A second glass window 44 for shielding the second opening 43 is adhered to the side wall. Further, on the outside of the package body 41 lead terminals 45 _1, 45 ₂ are implanted. These lead terminals 45 _1, 45 ₂ are connected monitor photodiode 42 and electrically.

The shapes of the package bodies 31, 41 of the first and second packages 23, 24 are both rectangular. These lead terminals 33 ₁ , 33 ₂ , 45 ₁ , 45
The shape of ₂ is Gull Wing, which is widely used in the small outline package of IC.
Type, either Butt Lead type or J Bend type is adopted. In this embodiment, a Jay bend type is employed.

As described above, in the present embodiment, the optical fiber 25 and the semiconductor laser 32, which have many restrictions on handling, are separated from the monitoring photodiode 42 and accommodated in the first package 23. For this reason, the second package 24 containing the monitor photodiode 42 is
5, the restriction conditions are reduced, and the shape and lead terminals 45 ₁ , 45 ₂
Is formed into a shape that can be surface-mounted, so that the second package 24 can be automatically mounted on the printed circuit board 21 by an automatic machine and can be automatically soldered by reflow or the like.

The first package 23 has to be soldered and mounted by hand as in the conventional case because there are many restrictions on handling. However, it has a surface mountable package shapes and the lead terminals 33 _1, 33 ₂ even for the first package 23. For this reason, attachment to the printed circuit board 21 is facilitated, and the size of the device can be reduced.

The precision of optical axis alignment between the first package 23 and the second package 24 is not so required. It is enough to set the arrangement of both by visual measurement. Therefore, the monitor function for the semiconductor laser 32 can be sufficiently performed only by performing the alignment on the pattern printed in advance.

Modification

FIG. 6 shows a package structure of a semiconductor laser module according to a modification of the present invention mounted on a printed circuit board. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. In this modified example, surface-mounted ICs 22 ₁ , 22
₂ and other electrical components 51 are mounted, and a first package 23 and a second package 52 are mounted. The first package 23 is exactly the same as that of the previous embodiment.

The second package 52 has a second opening 43 formed in one side wall thereof.
The monitor light which forms a part of the laser light emitted from the light source passes through the monitor light and enters the monitor photodiode 42. Other parts of the second package 52 include:
A semiconductor laser drive circuit for controlling the drive of the semiconductor laser 32 based on the intensity of the monitor light detected by the monitor photodiode 42 is provided, and the entire second package 52 is integrated as one IC package. ing.

Although the monitor light is received by the photodiode in the embodiments and the modifications described above, it is obvious that other light receiving elements can be used.

[0026]

As described above, according to the first aspect of the present invention, the conventional integrated semiconductor laser module is constituted by the first and second packages , and
Package lead terminals for surface mounting by automatic machines
Having used the thing, for the second package and the light receiving element for monitoring the optical fiber is not attached to arrangement enables automation when mounted on the printed board, it is possible to improve the efficiency of the work . Package 2
By separating them into two, the size of each package can be reduced, and the same shape as the conventional IC package can be obtained. That is, for example, they can be combined as a small outline package (SOP), and can be surface-mounted on a printed circuit board. As a result, mounting on a multilayer ceramic substrate becomes possible, and as a result, it can greatly contribute to downsizing of the device.

Further, the first package containing a semiconductor laser or the like can be easily mounted. Further, in the present invention, the semiconductor laser which is easily deteriorated by overvoltage or overcurrent is housed in a package different from the monitor photodiode, so that the monitor photodiode is housed even when the semiconductor laser is deteriorated. There is the advantage that the second package itself does not need to be replaced.

[0028]

[0029]

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a state in which a package of a semiconductor laser module according to an embodiment of the present invention is mounted on a printed circuit board.

FIG. 2 is a perspective view showing an appearance of a first package in the embodiment.

FIG. 3 is a sectional view of a first package according to the embodiment.

FIG. 4 is a perspective view illustrating an appearance of a second package according to the present embodiment.

FIG. 5 is a sectional view of a second package according to the embodiment.

FIG. 6 is a perspective view showing a state in which a package of a semiconductor laser module according to a modification of the present invention is mounted on a printed board.

FIG. 7 is a perspective view illustrating a package structure of a conventional semiconductor laser module.

[Explanation of symbols]

 Reference Signs List 21 printed board 23 first package 24, 52 second package 25 optical fiber 31, 41 package body 32 semiconductor laser 36 first opening 42 monitoring photodiode 43 second opening

Claims (1)

(57) [Claims] A printed circuit board, one end of an optical fiber, and a semiconductor laser for inputting an optical signal to the one end of the optical fiber are disposed so as to face inside.
And a first opening window for emitting a part of the light output from the semiconductor laser to the outside as monitor light, and a lead terminal electrically connected to the semiconductor laser , are respectively disposed on the wall. And connecting the lead terminals to the printing base.
A first package soldered to a predetermined position of the plate, together with the housing a light receiving element for detecting the monitor light therein, and a second open window for taking the monitoring light from said first opening window A lead terminal for surface mounting by an automatic machine electrically connected to the light receiving element is provided on a wall.
And the first and second opening windows are arranged for a predetermined time.
On the printed circuit board in an arrangement relationship facing each other with a gap
A second package that is surface-mounted by an automatic machine .