JP2010177518A - Stem for semiconductor laser device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stem for a semiconductor layer device which has high heat-dissipation performance and high versatility. <P>SOLUTION: A metal base 11 at least has a first principal plane and a second principal plane. Insulating leads 12, 13 are provided so as to penetrate the first principal plane and the second principal plane. A heat sink 16 has an installation surface 16a for fixing a semiconductor laser device 19, and promotes emission of heat to be generated from the semiconductor laser device 19. Here, a part 11e of the outer peripheral surface except the first principal plane and the second principal plane in the metal base 11 and a part 16d of the outer surface in the heat sink 16 are joined. Thus, it is easy to suitably change the volume and the shape of the heat sink 16 without changing design of the metal base 11, and even a case that the high heat-dissipation performance is required is easily dealt with. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stem for a semiconductor laser device, and more particularly to a structural improvement of a stem in which a semiconductor laser element is mounted in a semiconductor laser device used in an optical disc player or an optical disc recorder.

In recent years, the spread of optical disc players and optical disc recorders that read and write optical discs such as CDs, DVDs, and Blu-ray discs has been remarkable.
Many optical disc players and optical disc recorders use a semiconductor laser device as a device that emits laser light in order to read information recorded on the optical disc or record information on the optical disc.
The semiconductor laser device includes a semiconductor laser element that is a generation source of laser light. Since the semiconductor laser element generates a large amount of heat, the semiconductor laser device stem on which the semiconductor laser element is mounted is required to have high heat dissipation performance.

  As a conventional stem for a semiconductor laser device, a laser diode mounting base that is made of a metal having a higher thermal conductivity than that of the shell at a substantial center of the upper surface of the metal shell, A hermetic terminal for a laser diode (corresponding to a stem for a semiconductor laser device) having an earth lead wire provided on the bottom side of the shell is disclosed (see Patent Document 1).

FIG. 9 is a perspective view showing an example of a conventional stem 100 for a semiconductor laser device. FIG. 10 is a cross-sectional view of the semiconductor laser device stem 100 taken along the line X1-X2 in FIG.
9 and 10, a stem 100 for a semiconductor laser device includes a disk-like metal base 101 (corresponding to a metal shell of Patent Document 1) made of iron or an iron alloy containing iron as a main component, and is also made of iron or iron. The first insulating lead 102 and the second insulating lead 103 made of an iron alloy pass through, and the first insulating glass 104 and the second insulating glass 105 fill the gap between the metal base 101 and insulate them from each other. Sealed. The metal base 101 is embedded with a heat sink 106 made of copper or a copper alloy containing copper as a main component (corresponding to a laser diode mounting base of Patent Document 1), and together with a ground lead 107 made of iron or an iron alloy, a brazing material It is fixed via 108. A semiconductor laser element 109 is fixed to the heat sink 106.

According to the conventional stem 100 for a semiconductor laser device, since the lower part of the heat sink 106 having high thermal conductivity is embedded in the metal base 101, the upper part of the heat sink 106 (the part protruding from the metal base 101) is enlarged. In addition, the overall heat capacity can be increased by increasing the volume of the heat sink 106. Therefore, the overall heat capacity can be increased without increasing the outer shape of the stem 100 for the semiconductor laser device.
Japanese Patent Laid-Open No. 6-84555

  If it is necessary to improve the heat dissipation performance as the amount of heat generated increases due to higher output of the semiconductor laser device to be mounted, the heat capacity can be increased by changing the shape of the heat sink or increasing the volume. Measures are required to improve heat dissipation. However, since the heat sink is embedded in the metal base in the configuration of the above-described conventional technology, in order to increase the volume of the heat sink, it is basically necessary to increase the volume of the embedded portion, and only the heat sink design is changed. In addition, the metal-based design must be changed at the same time.

As described above, since the metal base has almost no versatility, the metal base cannot be used as a common component when, for example, a lineup of a plurality of products having different heat capacities is used. It cannot be suppressed.
Although it seems that it is not impossible to increase the volume of the heat sink by simply changing the heat sink design without changing the metal base design, the shape and volume of the heat sink actually depends on this metal base. Since it is greatly restricted by the embedded portion and may have problems such as a complicated shape, it is not practical.

  Therefore, an object of the present invention is to provide a stem for a semiconductor laser device having high heat dissipation and high versatility.

The present invention is directed to a semiconductor laser device stem on which a semiconductor laser element is mounted. In order to solve the above problems, the stem for a semiconductor laser device according to the present invention includes a metal base, an insulating lead, and a heat sink.
The metal base has at least a first main surface and a second main surface. The insulating lead is provided so as to penetrate the first main surface and the second main surface. The heat sink has an installation surface to which the semiconductor laser element is fixed, and promotes radiation of heat generated from the semiconductor laser element.
Here, the metal base and the heat sink are joined at a part of the outer peripheral surface other than the first main surface and the second main surface of the metal base and a part of the outer surface of the heat sink.

Preferably, a part of the outer peripheral surface of the metal base and a part of the outer surface of the heat sink include a portion that is in direct contact with each other without using a bonding material.
Preferably, a step having a shape engaging with each other may be formed on a part of the outer peripheral surface of the metal base and a part of the outer surface of the heat sink.

  As described above, in the present invention, since the volume and shape of the heat sink are not restricted in the portion embedded in the metal base as in the past, the volume and shape of the heat sink can be designed with the metal base. Without being changed, it is easy to change appropriately according to the output of the semiconductor laser element, the use conditions, etc., and even when high heat dissipation is required, it can be easily dealt with. Therefore, a semiconductor laser device stem having high heat dissipation and high versatility can be provided.

(First embodiment)
FIG. 1 is a perspective view of a stem 10 for a semiconductor laser device according to a first embodiment of the present invention. 2 is a front view of the semiconductor laser device stem 10 as viewed from the direction of the arrow X in FIG. FIG. 3 is a right side view of the semiconductor laser device stem 10 as seen from the direction of the arrow Y in FIG. FIG. 4 is a top view of the semiconductor laser device stem 10 as seen from the direction of the arrow Z in FIG. FIG. 5 is a bottom view of the semiconductor laser device stem 10 as viewed from the direction of the arrow Z ′ in FIG. 6 is a cross-sectional view of the semiconductor laser device stem 10 cut along the line X1-X2 in FIG. 7 is a cross-sectional view of the semiconductor laser device stem 10 cut along the line Y1-Y2 in FIG.

  A semiconductor laser device stem 10 is a stem for mounting a semiconductor laser element to constitute a semiconductor laser device. In FIGS. 1 to 7, a metal base 11, a first insulating lead 12, and a second insulating lead 13 are used. , First insulating glass 14, second insulating glass 15, heat sink 16, earth lead 17, and brazing material 18. In each figure, the semiconductor laser element 19 is shown in order to clarify the position where the semiconductor laser element is fixed. The semiconductor laser element 19 is fixed to the heat sink 16 and then connected to the first insulating lead 12 and the second insulating lead 13 (not shown), and a lid having a laser radiation window above the semiconductor laser element 19. And is incorporated into an optical pickup device having a function of adjusting the path and focus of the laser beam.

FIG. 8 is a cross-sectional view showing a state in which the metal base 11 and the heat sink 16 are separated from each other in a cross section similar to FIG.
The metal base 11 is made of plate-like iron or an alloy containing iron as a main component, and has a diameter of 1.0 to 3.3 from the first main surface on the upper side in FIG. 1 to the second main surface on the lower side in FIG. Two through holes 11a, 11b of about 0 mm are formed, and a part of the outer peripheral surface other than the first main surface and the second main surface, located between the first main surface and the second main surface, and its Joining portions 11c, 11d, and 11e are provided around the periphery. The shape of the metal base is generally a disk shape, but here a semicircular shape with a diameter of 8 to 12 mm and a plate thickness of about 1.0 to 2.0 mm so that it can be handled easily when joined to the heat sink 16. A slightly larger bow-shaped flat plate. Further, a step is provided in the portion corresponding to the bow-shaped string, and the stepped portion is formed as a joint portion 11c, 11d, 11e in order from the side close to the first main surface.

The first insulating lead 12 and the second insulating lead 13 are rod-shaped iron having a diameter of about 0.5 to 1.0 mm or an alloy containing iron as a main component, and penetrate each of the through holes 11a and 11b.
The first insulating glass 14 and the second insulating glass 15 are made of soda barium or borosilicate glass made of silicon dioxide or aluminum oxide, and the gap between the first insulating lead 12 and the metal base 11 and the second insulating lead 13, respectively. And the metal base 11 are filled and sealed to insulate them.

  The heat sink 16 is made of copper, silver, tungsten, molybdenum, aluminum, which is a metal generally having high thermal conductivity, or an alloy containing these as a main component, and is used for installing the semiconductor laser element 19. It has a smooth installation surface 16 a, and joints 16 b, 16 c, 16 d are sequentially provided adjacent to the lower side of the installation surface 16 a, and the semiconductor laser element 19 is fixed and generated from the semiconductor laser element 19 Promotes heat radiation. The shape of the heat sink 16 may be any shape as long as it has at least a smooth surface for installing the semiconductor laser element and a joining portion that is shaped to engage with the metal base. Here, for example, the heat sink 16 has a diameter of 7.5 to 11.5 mm and a height of 3 in order to have a high heat dissipation property and be as compact as possible when it becomes a final product. It has an arcuate column shape with a bottom surface slightly smaller than a semicircular shape of about 0.0 to 6.0 mm. Further, the upper part of the outer surface corresponding to the bow-shaped string is an installation surface 16a, and a step is provided at the lower part. Then, by joining the above-mentioned arcuate plate-shaped metal base 11 and the columnar heat sink 16 having an arcuate bottom surface to each other, the portions corresponding to the chords in each arcuate shape are joined to form a final product. It is made to be a substantially cylindrical shape. In addition, the area of the bottom 16e on the ground lead 17 side of the heat sink 16 is widened to increase the area directly exposed to the outside, thereby improving the heat dissipation. Further, for example, by increasing the surface area by forming irregularities on the surface of the heat sink 16, the heat dissipation can be further improved.

  Here, the heat sink 16 uses a material having higher thermal conductivity than the metal base 11. When the thermal conductivity of the metal base 11 and the heat sink 16 is different, it is advantageous in terms of heat dissipation performance to increase the heat conductivity of the heat sink 16, but the same material or the same thermal conductivity. A material may be used, and as a result, the thermal conductivity of the metal base 11 may be higher for reasons other than the thermal conductivity.

 For example, when copper is used for the heat sink 16, if copper is used for the metal base 11, there is a problem such as insufficient strength for sealing the insulating leads. However, considering the ease of handling and cost, the metal base 11 is currently preferably made of iron or an alloy containing iron as a main component. Therefore, when a metal such as copper, which generally has a high thermal conductivity, is used for the heat sink 16, a material with a higher thermal conductivity is necessarily used for the heat sink 16 than for the metal base 11.

Similarly to the first insulating lead 12 and the second insulating lead 13, the ground lead 17 is a rod-like iron having a diameter of about 0.5 to 1.0 mm or an alloy containing iron as a main component, and the bottom 16 e of the heat sink 16. It is fixed by brazing.
The brazing material 18 is a joining material that joins the metal base 11 and the heat sink 16 by fixing the joint portion 11e in the metal base 11 and the joint portion 16d in the heat sink 16 by brazing.

  Here, the brazing material 18 for joining the metal base 11 and the heat sink 16 and the brazing material (not shown) used when the heat sink 16 and the earth lead 17 are fixed to each other are nickel phosphorus (eutectic point: about 900 to 950 ° C.) and eutectic solder (copper / silver, eutectic point: about 800 ° C.) are suitable.

Further, the joint portions 11c, 11d, and 11e in the metal base 11 and the joint portions 16b, 16c, and 16d in the heat sink 16 form stepped shapes that engage with each other as shown in FIG. Includes a gap for accumulating the brazing filler metal 18 between the joint 11e and the joint 16d when the shape formed by the joints 11c and 11d and the shape formed by the joints 16b and 16c are combined with no gap. Is trying to be free.
The metal base 11 and the heat sink 16 may be joined by other methods such as caulking instead of brazing.

  With the structure as described above, the stem for the semiconductor laser device according to the first embodiment has the shape formed by the joint portions 11c and 11d and the shape formed by the joint portions 16b and 16c such as the brazing material 18 and the like. The thickness of the brazing material 18 can be varied by aligning it without gaps without using the bonding material, bringing them into direct contact with each other for positioning, and fixing the bonding portion 11e and the bonding portion 16d via the brazing material 18. The error due to is virtually eliminated.

  Further, the stem for the semiconductor laser device according to the first embodiment can increase the area of the bottom portion 16e of the heat sink 16, so that the area directly exposed to the outside increases and the heat dissipation of the heat sink 16 can be improved. . Furthermore, when the bottom surface 16e is brought into contact with a member having good thermal conductivity when incorporated into the optical pickup, the heat dissipation of the heat sink 16 can be further improved. The error due to the positional deviation between the metal base 11 and the heat sink 16 can be substantially eliminated.

  In the semiconductor laser device stem according to the first embodiment, the volume and shape of the heat sink 16 are not restricted in the portion embedded in the metal base as in the prior art. It is relatively easy to change the shape as appropriate according to the output of the semiconductor laser element, usage conditions, etc. without changing the design of the metal base, and even when high heat dissipation is required Yes. Further, for example, the shape of the heat sink 16 can be appropriately designed so as to match the shape of the space in which the semiconductor laser device on the apparatus side such as an optical disk player or optical disk recorder is incorporated, and in this way, the limited space is limited. It is possible to easily increase the volume of the heat sink 16 by effectively utilizing.

  In addition, compared with the conventional case where the heat sink is embedded in the metal base, the semiconductor laser device stem according to the first embodiment is considered to be more accurate because the joint portion between the metal base and the heat sink is easily processed. Therefore, it seems that the assembly accuracy is also excellent.

  The stem for the semiconductor laser device of the present invention is easy to change the design such as the shape of the heat sink and has high versatility, so it can be used for all types of semiconductor laser devices and the like, and has high heat dissipation. It is particularly suitable for high output semiconductor laser devices.

A perspective view of stem 10 for a semiconductor laser device concerning a 1st embodiment of the present invention. Front view of the semiconductor laser device stem 10 as seen from the direction of the arrow X in FIG. 1 is a right side view of the semiconductor laser device stem 10 as viewed from the direction of arrow Y in FIG. 1 is a top view of the semiconductor laser device stem 10 as viewed from the direction of arrow Z in FIG. A bottom view of the semiconductor laser device stem 10 as seen from the direction of the arrow Z 'in FIG. 1 is a cross-sectional view of the semiconductor laser device stem 10 taken along line X1-X2 in FIG. 1 is a cross-sectional view of the semiconductor laser device stem 10 taken along the line Y1-Y2 in FIG. Sectional drawing which shows the state which isolate | separated the metal base 11 and the heat sink 16 in the cross section according to FIG. A perspective view showing an example of a conventional stem 100 for a semiconductor laser device 9 is a cross-sectional view of the semiconductor laser device stem 100 taken along line X1-X2 in FIG.

DESCRIPTION OF SYMBOLS 10 Semiconductor laser apparatus stem 11 Metal base 11a, 11b Through-hole 11c, 11d, 11e Joint part 12 1st insulation lead 13 2nd insulation lead 14 1st insulation glass 15 2nd insulation glass 16 Heat sink 16a Installation surface 16b, 16c, 16d Joint 16e Bottom 17 Ground lead 18 Brazing material 19 Semiconductor laser device

Claims (3)

A semiconductor laser device stem on which a semiconductor laser element is mounted,
A metal base having at least a first main surface and a second main surface;
At least one insulating lead provided so as to penetrate the first main surface and the second main surface;
A heat sink that has an installation surface for fixing the semiconductor laser element, and that promotes radiation of heat generated from the semiconductor laser element;
The metal base and the heat sink are joined at a part of the outer peripheral surface other than the first main surface and the second main surface of the metal base and a part of the outer surface of the heat sink. A stem for a semiconductor laser device.   The part of the outer peripheral surface of the metal base and the part of the outer surface of the heat sink include a portion that is in direct contact with each other without using a bonding material and is used for positioning. 2. A stem for a semiconductor laser device according to 1.   2. The semiconductor laser device according to claim 1, wherein a step having a shape engaging with each other is formed on a part of the outer peripheral surface of the metal base and a part of the outer surface of the heat sink. Stem.

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