JP2000340874A - Semiconductor laser module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a semiconductor laser module which is not damaged, even when internal stresses are generated between components as the result of thermal expansion or thermal contraction in each component. SOLUTION: When an environmental temperature changes and the height of a package 11 is changed, deviation is generated between the height position of an upper part of a mount for an electric signal line and the height position of an upper part of a chip mount 13. Since both ends of a conductor plate 51 are bonded to the mount 20 and the mount 13, this means that a load is applied to the conductor plate 51. Since the plate 51 is constituted as a single- layer structure in a section between a printed board 41 and a printed board 42, deflection is generated in the part and the load due to deviation of the height positions is absorbed.

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, and more particularly, to a semiconductor laser module for converting an electric signal into an optical signal.

[0002]

2. Description of the Related Art In recent years, with the advance of advanced information technology, in the field of optical communication, a system for optically transmitting digital signals, microwave signals, millimeter-wave signals, and the like having a transmission speed exceeding 10 Gb / s is required. It has become to. Needless to say, a semiconductor laser module as a light source is required to have a wider band.

[0003] In a semiconductor laser module having a built-in Peltier element for temperature control, the Peltier element has a large capacitor capacity, and this capacitor capacity is a factor that limits the broadening of the frequency band. As a method for widening the bandwidth, for example, Japanese Patent Application Laid-Open
One example is shown in -125997. Hereinafter, a conventional semiconductor laser module disclosed in Japanese Patent Application Laid-Open No. 10-125997 will be described with reference to FIGS.

FIG. 8 is a sectional view of a conventional semiconductor laser module disclosed in Japanese Patent Application Laid-Open No. 10-125997. FIG. 9 is a diagram of the portion A in FIG. 8 as viewed from above.

In FIG. 8, a lens mount 714 is placed on a Peltier element 712 soldered to the bottom of a package 711. Lens mount 714
A chip mount 713 is soldered on the semiconductor laser chip 71 on the chip mount 713.
0 is held. The semiconductor laser chip 710 emits light in a direction perpendicular to the plane of the drawing. A lens or the like for condensing light is provided in the package 711, but is not shown.

As shown in FIG. 9, electric signal lines 728a and 728b are formed on an insulating plate 732 attached to a side wall of a package 711. An electric signal is externally applied to the electric signal line 728a, and the electric signal line 728b is grounded. The ceramic plate 733 is bridged between the insulating plate 732 and the chip mount 713. An electric signal line 733a is formed on the front surface of the ceramic plate 733, and a conductive film 733b is formed on the back surface. One end of the conductive film 733b formed on the back surface of the ceramic plate 733 is connected to the chip mount 713, and the other end is connected to the electric signal line 728b.
Therefore, the chip mount 713 is grounded through the conductive film 733b and the electric signal line 728b. One end of the electric signal line 733a is a wire 730.
And the other end is connected to the electric signal line 728a via the wire 30.

In order to reduce the effect of the capacitance of the capacitor of the Peltier element 712 and extend the frequency band over a wide band, it is necessary to minimize the distance between the chip mount 713 and the electric signal line 728b grounded to the ground. is there. In JP-A-10-125997, a chip mount 713 and an electric signal line 7 grounded to the ground are described.
The band is broadened by placing a ceramic plate 733 provided with a conductive film 733b between the ceramic plate 283 and the conductive film 733b.

[0008]

The Peltier device 712 as a temperature variable device operates so that the temperature of the semiconductor laser chip 710 becomes constant. Lens mount 71
4 and the chip mount 713 are also the semiconductor laser chip 71.
This means that the temperature is kept the same as 0. By the way, when the ambient temperature of the package 711 increases, the package 71
1 causes thermal expansion, and a shift occurs between the height position of the portion where the ceramic plate 733 is joined to the chip mount 713 and the height position of the portion where the ceramic plate 733 is joined to the insulating plate 732. Will be. Package 711
Is Cu-W, the coefficient of thermal expansion is about 10
× 10 ⁻⁶ [1 / ° C.]. The height from the bottom of the package 711 to the insulating plate 732 is about 5 mm. When the ambient temperature changes by ± 50 ° C. with reference to 25 ° C., the height of the left and right sides of the ceramic plate 733 changes by ± 2.5 μm. Therefore, the chip mount 713 and the ceramic plate 7
33, or between the ceramic plate 733 and the insulating plate 73.
There is a possibility that a load is applied to the bonding surface between the semiconductor laser module 2 and the bonding portion, and the ceramic plate 733 is peeled off from the chip mount 713 or the insulating plate 732, thereby deteriorating the reliability of the semiconductor laser module.

Therefore, an object of the present invention is to provide a semiconductor laser module which is less likely to be damaged even if an internal stress is generated between components due to thermal expansion or thermal contraction of each component due to fluctuations in ambient temperature. To provide.

[0010]

Means for Solving the Problems and Effects of the Invention The present invention has the following features in order to achieve the above object.

According to a first aspect of the present invention, there is provided a semiconductor laser module for converting an electric signal into an optical signal, comprising: a package; a Peltier device provided at an inner bottom of the package;
A chip mount provided on top of the Peltier element, a semiconductor laser chip provided on top of the chip mount, and an electric signal introduction unit provided on a side surface of the package for guiding an externally applied electric signal to the inside of the package And, a conductor plate bridged between the electric signal introduction unit and the chip mount, and a plurality of printed circuit boards provided at predetermined intervals on the conductor plate, each having an electric signal line formed thereon. Wire means for wiring so that an electric signal introduced by the electric signal introduction unit is supplied to the semiconductor laser chip via an electric signal line on each printed circuit board. It is characterized by having a structure that bends easily between them.

As described above, according to the first aspect, even if the ambient temperature of the semiconductor laser module fluctuates, the portion of the conductor plate in the gap between the printed circuit boards bends, so that the chip mount and the conductor plate are displaced. It is possible to prevent cracks between the electric signal introducing portion and the conductor plate, and to prevent the conductor plate from peeling off.

A second invention is an invention according to the first invention, wherein a printed circuit board for testing the semiconductor laser chip is provided in advance with the semiconductor laser chip above the chip mount, The wiring means is arranged so that the electric signal introduced by the electric signal introducing unit is supplied to the semiconductor laser chip via the electric signal line on each printed circuit board and the test printed circuit board.

As described above, according to the second aspect of the present invention, a printed circuit board for testing is installed together with the semiconductor laser chip on the chip mount in advance and wired to each other, thereby assembling parts inside the module. At this time, wires and the like may be attached to the printed circuit board on the chip mount instead of attaching the wires and the like to the semiconductor laser chip, so that the working efficiency can be improved.

A third invention is a semiconductor laser module for converting an electric signal into an optical signal, comprising a package, a Peltier device provided at an inner bottom of the package,
A chip mount provided on top of the Peltier element, a semiconductor laser chip provided on top of the chip mount, and an electric signal introduction unit provided on a side surface of the package for guiding an externally applied electric signal to the inside of the package And a conductor plate bridged between the electric signal introduction unit and the chip mount, one printed circuit board provided on the conductor plate and having electric signal lines formed thereon, and an electric signal introduction unit. Wire means for wiring so that the supplied electric signal is supplied to the semiconductor laser chip via an electric signal line on the printed circuit board, and the length of the printed circuit board is sufficiently longer than the length of the conductive plate. Chosen short,
The conductor plate is characterized in that it has a structure that bends easily at the end where the printed board is not provided.

As described above, according to the third aspect of the present invention, even if the ambient temperature of the semiconductor laser module fluctuates, the portion of the conductor plate at the end of the printed circuit board bends, so that the connection between the chip mount and the conductor plate is reduced. It is possible to prevent cracks between the conductors and between the electric signal line mount and the conductor plate, and prevent the conductor plate from peeling off.

A fourth invention is an invention according to the third invention, wherein a printed circuit board for testing the semiconductor laser chip is provided in advance on the chip mount together with the semiconductor laser chip, The wiring means is arranged so that the electric signal introduced by the electric signal introducing unit is supplied to the semiconductor laser chip via the electric signal line on each printed circuit board and the test printed circuit board.

As described above, according to the fourth aspect of the present invention, a test printed circuit board and a semiconductor laser chip are previously mounted on a chip mount and wired to each other, thereby assembling parts inside the module. At this time, wires and the like may be attached to the printed circuit board on the chip mount instead of attaching the wires and the like to the semiconductor laser chip, so that the working efficiency can be improved.

According to a fifth aspect of the present invention, there is provided a semiconductor laser module for converting an electric signal into an optical signal, comprising: a package; a Peltier device provided at an inner bottom of the package;
A chip mount provided on top of the Peltier element, a semiconductor laser chip provided on top of the chip mount, and an electric signal introduction unit provided on a side surface of the package for guiding an externally applied electric signal to the inside of the package A metal block provided inside the package and below the electric signal introducing portion and closely attached to at least a side surface of the package; a conductor plate bridged between the metal block and the chip mount; And a plurality of printed circuit boards on which electric signal lines are formed, and an electric signal introduced by the electric signal introduction unit is connected to the semiconductor laser via the electric signal lines on each printed circuit board. Wire means for wiring so as to be supplied to the chip, and the conductor plate has a structure that easily bends between each printed circuit board. And characterized in that it.

As described above, according to the fifth aspect, even if the ambient temperature of the semiconductor laser module fluctuates, the portion of the conductor plate in the gap between the printed circuit boards bends, so that the chip mount and the conductor plate are not bent. It is possible to prevent cracks between the metal block and the metal block and the conductor plate, and prevent the conductor plate from peeling off.

A sixth invention is an invention according to the fifth invention, wherein a printed circuit board for testing the semiconductor laser chip is provided on an upper part of the chip mount together with the semiconductor laser chip, The wiring means is arranged so that the electric signal introduced by the electric signal introducing unit is supplied to the semiconductor laser chip via the electric signal line on each printed circuit board and the test printed circuit board.

As described above, according to the sixth aspect of the present invention, a test printed circuit board and a semiconductor laser chip are mounted on a chip mount in advance and wired to each other, thereby assembling parts inside the module. At this time, wires and the like may be attached to the printed circuit board on the chip mount instead of attaching the wires and the like to the semiconductor laser chip, so that the working efficiency can be improved.

A seventh invention is the invention according to the fifth invention, wherein the coefficient of thermal expansion of the metal block is smaller than the coefficient of thermal expansion of the package.

As described above, according to the seventh aspect, the thermal expansion coefficient of the metal block is smaller than the thermal expansion coefficient of the package. Can be. As a result, the mechanical load applied to the conductor plate is reduced, and a semiconductor laser module that is more difficult to break can be obtained.

An eighth invention is an invention according to the seventh invention, wherein a notch or a step is provided in a portion of the metal block facing the electric signal introducing portion.

As described above, according to the eighth aspect of the invention, the notch or the step is provided in a portion of the metal block facing the electric signal introduction portion, so that the electric signal introduction portion and the metal block are formed due to a difference in thermal expansion coefficient. In such a case, interference is prevented from occurring at a portion opposed to the above.

A ninth invention is a semiconductor laser module for converting an electric signal to an optical signal, comprising: a package; a Peltier device provided at an inner bottom of the package;
A chip mount provided on top of the Peltier element, a semiconductor laser chip provided on top of the chip mount, and an electric signal introduction unit provided on a side surface of the package for guiding an externally applied electric signal to the inside of the package And a metal block provided inside the package and below the electric signal introducing portion and closely attached to at least a side surface of the package, a conductor plate bridged between the metal block and the chip mount, and provided on the conductor plate. A printed circuit board on which an electric signal line is formed, and wiring so that the electric signal introduced by the electric signal introducing section is supplied to the semiconductor laser chip via the electric signal line on the printed circuit board. And the length of the printed circuit board is selected to be sufficiently shorter than the length of the conductive plate. Characterized in that it has a readily flexed structure at a portion where bets substrate is not provided.

As described above, according to the ninth aspect, even if the ambient temperature of the semiconductor laser module fluctuates, the portion of the conductor plate at the end of the printed circuit board bends, so that the connection between the chip mount and the conductor plate is prevented. Cracks between the metal blocks and between the metal block and the conductive plate, and peeling of the conductive plate can be prevented.

A tenth invention is an invention according to the ninth invention, wherein a printed circuit board for testing the semiconductor laser chip is provided above the chip mount together with the semiconductor laser chip. The wiring means is arranged so that the electric signal introduced by the electric signal introducing unit is supplied to the semiconductor laser chip via the electric signal line on each printed circuit board and the test printed circuit board.

As described above, according to the tenth aspect, the semiconductor laser chip is mounted on the chip mount in advance.
By installing test printed circuit boards and wiring them together, when assembling components inside the module, instead of attaching wires etc. to the semiconductor laser chip, it is only necessary to attach wires etc. to the printed board on the chip mount, Work efficiency can be improved.

An eleventh invention is an invention according to the ninth invention, wherein the coefficient of thermal expansion of the metal block is smaller than the coefficient of thermal expansion of the package.

As described above, according to the eleventh aspect, since the coefficient of thermal expansion of the metal block is smaller than the coefficient of thermal expansion of the package, it is possible to reduce the deviation between the left and right heights of the conductor plate caused by a temperature change. Can be. As a result, the mechanical load applied to the conductor plate is reduced, and a semiconductor laser module that is more difficult to break can be obtained.

A twelfth aspect is the invention according to the eleventh aspect, wherein a notch or a step is provided in a portion of the metal block facing the electric signal introducing portion.

As described above, according to the twelfth aspect, the notch or the step is provided in a portion of the metal block facing the electric signal introducing portion, so that the electric signal introducing portion and the metal block are formed due to a difference in thermal expansion coefficient. In such a case, interference is prevented from occurring at a portion opposed to the above.

[0035]

FIG. 1 is a diagram showing a cross section of a semiconductor laser module according to a first embodiment of the present invention. FIG. 2 is a view of the portion B in FIG. 1 as viewed from above.

In FIG. 1, a chip mount 13 is soldered on a Peltier device 12 soldered to the bottom surface of a package 11. Tip mount 13
A semiconductor laser chip 10 is held on the substrate.
The semiconductor laser chip 10 emits light in a direction perpendicular to the paper surface. A lens or the like for condensing light is provided in the package 11, but is not shown.

A through hole is formed in a side wall of the package 11, and a mount 20 for an electric signal line is mounted in the through hole. The electric signal line mount 20 is made of an insulator. As shown in FIG. 2, electric signal lines 21a and 21b are formed on the electric signal line mount 20. An electric signal from the outside of the package is applied to the electric signal line 21a, and the electric signal line 21b is grounded. Electric signal line mount 20
A bridge between the chip mount 13 and the conductor plate 51 is provided. Thus, the conductor plate 51 is connected to the chip mount 13 and to the electric signal line 21b. On the conductor plate 51, two printed circuit boards 4
1 and 42 are attached at a predetermined interval. The base material of the printed boards 41 and 42 is ceramic. However, a fluorine resin or a glass epoxy resin may be used. In the present embodiment, two printed boards are mounted on the conductive plate 51, but more printed boards may be provided. On the printed boards 41 and 42, electric signal lines 33a are wired. Between one end of the electric signal line 21a wired on the electric signal line mount 20 and the electric signal line 33a on the printed circuit board 41, and between the electric signal line 33a on the printed circuit board 41 and the printed circuit board 42. Electrical signal line 33
a between the electrical signal line 33a on the printed circuit board 42 and the semiconductor laser chip 10,
Connected by

An electric signal to be supplied to the semiconductor laser chip 10 is transmitted to the package 1 via an electric signal line 21a.
1 is input from outside. Thereafter, the electric signal is supplied to the semiconductor laser chip 10 through the electric signal line 33a and the wire 30 on the upper portions of the printed boards 41 and 42. In addition, the semiconductor laser chip 10
Is grounded to the ground via the chip mount 13, the conductor plate 51, and the electric signal line 21b. Thus, the semiconductor laser chip 10 can be driven.

As described above, by providing the conductor plate 51 between the electric signal line 21b and the chip mount 13, the electric distance between the semiconductor laser chip 10 and the package 11 can be shortened. As a result, the effect of the capacitance of the Peltier element 12 can be reduced, and the frequency band can be extended over a wide band.

Now, it is assumed that the ambient temperature changes and the height of the package 11 changes. At this time, a deviation occurs between the height position above the electric signal line mount 20 and the height position above the chip mount 13. As described above, when the height position shifts, since both ends of the conductor plate 51 are bonded to the electric signal line mount 20 and the chip mount 13, a load may be applied to the conductor plate 51. become. However, the conductor plate 51
A single-layer structure between the printed circuit board 41 and the printed circuit board 42 (that is, a structure without a printed circuit board)
, Deflection occurs at that portion, thereby absorbing the load received from the displacement of the height position. As described above, by forming a part of the conductor plate 51 so as to be easily bent, cracks are formed between the chip mount 13 and the conductor plate 51 or between the electric signal line mount 20 and the conductor plate 51. Can be prevented from entering. Further, the conductor plate 51 is mounted on the chip mount 13 or the electric signal line mount 20.
From the surface.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
It is a figure showing the section of the semiconductor laser module concerning an embodiment. In FIG. 3, in the semiconductor laser module of the present embodiment, the electric signal line mount 20 and the chip mount 13 are bridged by a conductor plate 52, and one printed Substrate 43
Is attached. However, the length of the printed circuit board 43 is sufficiently shorter than the length of the conductor plate 52. Other configurations of the present embodiment are the same as those of the first embodiment. Corresponding portions have the same reference characters allotted, and description thereof will not be repeated.

In this embodiment, when a difference occurs between the height position of the upper part of the electrical signal line mount 20 and the height position of the upper part of the chip mount 13 due to a change in the ambient temperature, the conductor plate 52 Is applied to the conductor plate 52
Is absorbed by bending at the end portion between the chip mount 13 and the printed circuit board 43. That is, since the portion of the conductor plate 52 between the chip mount 13 and the printed circuit board 43 has a single-layer structure, the portion is easily bent. As described above, in the present embodiment, similarly to the case of the above-described first embodiment, the conductive plate 5
By making a part of 2 a structure that easily causes deflection,
Cracks can be prevented between the chip mount 13 and the conductor plate 52 and between the electric signal line mount 20 and the conductor plate 52. Further, it is possible to prevent the conductive plate 52 from peeling off from the chip mount 13 or the electric signal line mount 20.

(Third Embodiment) FIG. 4 shows a third embodiment of the present invention.
It is a figure showing the section of the semiconductor laser module concerning an embodiment. FIG. 5 is a view of a portion C in FIG. 3 as viewed from above.

4 and 5, in this embodiment, a metal block 15 is attached in close contact with the inner side wall of the package 11. This metal block 15
It is grounded through the package 11 to the ground.
Then, one end of the electric signal line mount 20 and one end of the conductor plate 51 are mounted on the metal block. One end of the conductor plate 51 needs to be fixed on the metal block 15, but one end of the electric signal line mount 20 may be simply placed on the metal block 15.

As described above, in the present embodiment, the conductive plate 5
1 bridges between the metal block 15 and the chip mount 13. On this conductor plate 51, the first
In the same manner as in the embodiment, the two printed circuit boards 41 and 4
2 are attached at a predetermined interval. In the present embodiment, two printed boards are mounted on the conductor plate 51, but more printed boards may be provided. Also, the electric signal line mount 20
An electric signal line 21a is formed on the upper side. Then, between one end of the electric signal line 21a wired on the electric signal line mount 20 and the electric signal line 33a on the printed circuit board 41, and between the electric signal line 33a on the printed circuit board 41 and the printed circuit board 42. The electrical signal line 33a on the printed circuit board 42 and the electrical signal line 33a on the printed circuit board 42 and the semiconductor laser chip 10 are connected by wires 30 respectively. Other configurations of the present embodiment are the same as those of the above-described first embodiment. Corresponding portions are denoted by the same reference numerals, and description thereof will be omitted.

An electric signal to be supplied to the semiconductor laser chip 10 is supplied to the package 1 via an electric signal line 21a.
1 is input from outside. Thereafter, the electric signal is supplied to the semiconductor laser chip 10 through the electric signal line 33a and the wire 30 on the upper portions of the printed boards 41 and 42. In addition, the semiconductor laser chip 10
Are the chip mount 13, the conductor plate 51, and the metal block 1.
5 and ground via the package 11. Thus, the semiconductor laser chip 10 can be driven.

As described above, the electric block 15 is provided so as to be in close contact with the inner side wall of the package 11, and the conductor plate 51 is provided between the metal block 15 and the chip mount 13 so that the semiconductor laser chip 10 The effective electrical distance from the package 11 can be further reduced. As a result, the effect of the capacitor capacitance of the Peltier element 12 can be further reduced, and the frequency band can be extended over a wide band.

In the present embodiment, when a difference occurs between the height position above the metal block 15 and the height position above the chip mount 13 due to a change in the ambient temperature,
A load is applied to the conductor plate 51, and the load is absorbed by the flexure of the conductor plate 51 at a portion between the printed board 41 and the printed board 42. This is the same as the load absorbing structure in the first embodiment. In this embodiment, the package 1 is used as the metal block 15.
By using a material having a coefficient of thermal expansion smaller than the coefficient of thermal expansion of 1, compared to the first embodiment,
The load applied to the conductor plate 51 due to the change in the ambient temperature can be reduced. However, if the ambient temperature is lower than the internal temperature of the package 11, the package 1
Since the heat shrinkage of 1 is greater than the heat shrinkage of the metal block 15, the lower part of the electric signal line mount 20 may come into contact with the upper part of the metal block 15, and the electric signal line mount 20 may be separated from the package 11. . Therefore, it is preferable to provide a notch or a step on the upper portion of the metal block 15 facing the lower portion of the electric signal line mount 20 to avoid contact.

As described above, in the present embodiment, the conductive plate 5
By making a part of 1 easy to bend,
Cracks can be prevented between the chip mount 13 and the conductor plate 51 and between the metal block 15 and the conductor plate 51. In addition, it is possible to prevent the conductor plate 51 from peeling off from the chip mount 13 or the metal block 15.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment of the present invention.
It is a figure showing the section of the semiconductor laser module concerning an embodiment. In FIG. 6, in the semiconductor laser module of the present embodiment, the metal block 15 and the chip mount 13
Is bridged by a conductor plate 52, and a single printed circuit board 43 is mounted on the conductor plate 52. However, the length of the printed circuit board 43 is sufficiently shorter than the length of the conductor plate 52. Other configurations of the present embodiment are the same as those of the above-described third embodiment, and corresponding portions are denoted by the same reference numerals, and description thereof will be omitted.

When the ambient temperature changes and the height of the metal block 15 changes, the load applied to the conductor plate 52 is
The conductor plate 52 is absorbed by bending at a portion between the chip mount 13 and the printed board 43. Such a load absorbing structure is the same as in the above-described second embodiment.

(Fifth Embodiment) FIG. 7 shows a fifth embodiment of the present invention.
It is a figure showing the section of the semiconductor laser module concerning an embodiment. 7, a printed circuit board 40 is held on the chip mount 13 together with the semiconductor laser chip 10 in advance. The printed circuit board 40 is used for testing the semiconductor laser chip 10 before assembling the module, on which electric signal lines are wired. The electrical signal lines on the printed circuit board 40 and the semiconductor laser chip 10 are connected by wires 30. That is, it is necessary to supply some drive signal to the semiconductor laser chip 10 at the time of a test. Therefore, it is troublesome to directly wire-bond the semiconductor laser chip 10 to the semiconductor laser chip 10, and the semiconductor laser chip 10 may be damaged. is there. Therefore, by providing a printed circuit board 40 connected to the semiconductor laser chip 10 on the chip mount 13 in advance, the wiring work at the time of the test is facilitated and the semiconductor laser chip 10 is prevented from being damaged. I have.

As in the case of the third embodiment described with reference to FIG. 5, one end of the electric signal line 21a wired on the electric signal line mount 20 and the electric signal on the printed circuit board 41. The wires 30 are connected to the wires 33a and between the electric signal lines 33a on the printed circuit board 41 and the electric signal lines 33a on the printed circuit board 42, respectively. In addition, a wire 3 is also provided between the electric signal line 33a on the printed board 42 and the electric signal line on the printed board 40.
0 is connected. Other configurations of the present embodiment are the same as those of the third embodiment, and the corresponding portions are denoted by the same reference numerals, and description thereof will be omitted.

When the ambient temperature changes and the height of the metal block 15 changes, the load applied to the conductor plate 51 is:
The conductor plate 51 is absorbed by bending at a portion between the printed boards 41 and 42. Such a load absorbing structure is the same as in the third embodiment.

In the fifth embodiment, the electric signal lines on the printed circuit board 40 and the semiconductor laser chip 1
0 is previously connected by the wire 30, so that when assembling parts in the module, the printed circuit board 42 is not connected.
The electric signal line 33a on the printed circuit board is not directly connected to the semiconductor laser chip 10, but is connected to the electric signal line on the printed circuit board 40. Generally, wiring to the semiconductor laser chip 10 involves difficulties due to the fine work involved, but wiring between printed boards is easier than that.
Therefore, it can be said that the present embodiment is superior in assembling workability as compared with the third embodiment.

In the fifth embodiment, the printed circuit board 40 is provided together with the semiconductor laser chip 10 on the chip mount 13 in advance in the configuration of the third embodiment. Regardless of the embodiment, also in the first, second and fourth embodiments, a printed circuit board 40 may be provided on the chip mount 13 together with the semiconductor laser chip 10 in advance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section of a semiconductor laser module according to a first embodiment of the present invention.

FIG. 2 is a view of a portion B in FIG. 1 as viewed from above.

FIG. 3 is a diagram showing a cross section of a semiconductor laser module according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a cross section of a semiconductor laser module according to a third embodiment of the present invention.

FIG. 5 is a view of a portion C in FIG. 4 as viewed from above.

FIG. 6 is a diagram showing a cross section of a semiconductor laser module according to a fourth embodiment of the present invention.

FIG. 7 is a diagram showing a cross section of a semiconductor laser module according to a fifth embodiment of the present invention.

FIG. 8 is a diagram showing a cross section of a conventional semiconductor laser module.

FIG. 9 is a view of the portion A in FIG. 8 as viewed from above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Semiconductor laser chip 11 ... Package 12 ... Peltier element 13 ... Chip mount 15 ... Metal block 20 ... Electric signal line mount 21 ... Electric signal line 30 ... Wires 40, 41, 42, 43, 47, 48 ... Printed circuit board 51 , 52, 53, 54 ... conductor plate

Claims (12)

[Claims] 1. A semiconductor laser module for converting an electric signal into an optical signal, comprising: a package; a Peltier device provided on an inner bottom of the package; and a chip mount provided on an upper portion of the Peltier device. A semiconductor laser chip provided on an upper portion of the chip mount; an electric signal introduction unit provided on a side surface of the package for guiding an externally applied electric signal to the inside of the package; A conductor plate bridged between the conductor plate and a chip mount; a plurality of printed circuit boards provided on the conductor plate at predetermined intervals, each having an electric signal line formed thereon; Wiring so that the electric signal introduced by the above is supplied to the semiconductor laser chip via an electric signal line on each of the printed circuit boards. And a fit of the wire means, said conductive plate, characterized in that it has a readily flexed structure between each of said printed circuit board, the semiconductor laser module. 2. A printed circuit board for testing the semiconductor laser chip is provided on the upper part of the chip mount together with the semiconductor laser chip, and the wire means is introduced by the electric signal introduction unit. 2. The semiconductor laser module according to claim 1, wherein wiring is performed so that an electric signal is supplied to the semiconductor laser chip via an electric signal line on each of the printed circuit boards and the test printed circuit board. 3. . 3. A semiconductor laser module for converting an electric signal to an optical signal, comprising: a package; a Peltier device provided on an inner bottom of the package; and a chip mount provided on an upper portion of the Peltier device. A semiconductor laser chip provided on an upper portion of the chip mount; an electric signal introduction unit provided on a side surface of the package for guiding an externally applied electric signal to the inside of the package; A conductor plate bridged between the chip mount, a single printed circuit board provided on the conductor plate and having an electric signal line formed thereon, and an electric signal introduced by the electric signal introduction unit. Wire means for wiring so as to be supplied to the semiconductor laser chip via an electric signal line on the printed circuit board, The length of the printed board is selected to be sufficiently shorter than the length of the conductive board, and the conductive board has a structure that bends easily at an end portion where the printed board is not provided. A semiconductor laser module, characterized in that: 4. A printed circuit board for testing the semiconductor laser chip is provided in advance on the chip mount together with the semiconductor laser chip, and the wire means is introduced by the electric signal introduction unit. 4. The semiconductor laser module according to claim 3, wherein wiring is performed so that an electric signal is supplied to the semiconductor laser chip via an electric signal line on each of the printed circuit boards and the test printed circuit board. 5. . 5. A semiconductor laser module for converting an electric signal into an optical signal, comprising: a package; a Peltier device provided on an inner bottom of the package; and a chip mount provided on an upper portion of the Peltier device. A semiconductor laser chip provided on an upper part of the chip mount; an electric signal introduction unit provided on a side surface of the package for guiding an externally applied electric signal to the inside of the package; A metal block provided at a lower portion of the electric signal introduction unit and closely attached to at least a side surface of the package; a conductor plate bridged between the metal block and the chip mount; and a predetermined gap above the conductor plate. A plurality of printed circuit boards, which are provided at intervals, and on each of which an electric signal line is formed; and Wire means for wiring so that the introduced electric signal is supplied to the semiconductor laser chip via an electric signal line on each of the printed circuit boards, wherein the conductive plate is provided between each of the printed circuit boards. Wherein the semiconductor laser module has a structure that bends easily. 6. A printed circuit board for testing the semiconductor laser chip is provided in advance on the chip mount together with the semiconductor laser chip, and the wire means is introduced by the electric signal introduction unit. 6. The semiconductor laser module according to claim 5, wherein wiring is performed so that an electric signal is supplied to the semiconductor laser chip via an electric signal line on each of the printed circuit boards and the test printed circuit board. . 7. The semiconductor laser module according to claim 5, wherein a coefficient of thermal expansion of the metal block is smaller than a coefficient of thermal expansion of the package. 8. The semiconductor laser module according to claim 7, wherein a notch or a step is provided in a portion of said metal block facing said electric signal introducing portion. 9. A semiconductor laser module for converting an electric signal into an optical signal, comprising: a package; a Peltier element provided on an inner bottom of the package; and a chip mount provided on an upper part of the Peltier element. A semiconductor laser chip provided on an upper part of the chip mount; an electric signal introduction unit provided on a side surface of the package for guiding an externally applied electric signal to the inside of the package; A metal block provided at a lower portion of the electric signal introduction unit and closely attached to at least the side surface of the package, a conductor plate bridged between the metal block and the chip mount, and provided on the conductor plate, One printed circuit board having an electric signal line formed thereon, and an electric signal introduced by the electric signal introduction unit Has a wire means for wiring so as to be supplied to the semiconductor laser chip via an electric signal line on the printed board, wherein the length of the printed board is sufficiently longer than the length of the conductor plate. The semiconductor laser module, which is selected to be short, has a structure in which the conductor plate easily bends in a portion where the printed board is not provided. 10. A printed circuit board for testing the semiconductor laser chip is provided in advance on the chip mount together with the semiconductor laser chip, and the wire means is introduced by the electric signal introduction unit. 10. The semiconductor laser module according to claim 9, wherein wiring is performed so that an electric signal is supplied to the semiconductor laser chip via an electric signal line on each of the printed circuit boards and the test printed circuit board. . 11. The semiconductor laser module according to claim 9, wherein a coefficient of thermal expansion of the metal block is smaller than a coefficient of thermal expansion of the package. 12. The semiconductor laser module according to claim 11, wherein a notch or a step is provided in a portion of the metal block facing the electric signal introducing portion.