JPS58220481A - Assembly method of semiconductor light emitting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a semiconductor light emitting device, and particularly to a method for assembling a semiconductor light emitting device in which optical components are disposed close to a semiconductor light emitting element.

(b) Prior Art and Problems In optical fiber communication and other technologies that use light as an information signal medium, a semiconductor light emitting device such as a semiconductor laser that generates an optical signal is the most important and basic component.

However, since the light emitted from a semiconductor light emitting device such as a semiconductor laser spreads with a large radiation angle, it is not easy to focus this light and introduce it into a thin optical fiber.
In addition to the direct coupling method, in which the tip of the optical fiber faces the light emitting area as close as possible, there are also the tip lens method, in which the tip of the optical fiber is processed into a lens shape, and the individual coupling method, in which a coupling optical system such as an independent lens is inserted. A lens method is used. Even in these tip lens systems and individual lens systems, it is necessary to bring the lens, etc. as close as possible to the light emitting area in order to reduce coupling loss, and to place it at a position where it receives the maximum luminous flux. 0 As a result, a structure in which an optical fiber, a coupling optical system, or both are built into a semiconductor light emitting device is widely used. An example of a conventional optical fiber direct coupling type semiconductor light emitting device is shown in cross-sectional view in FIG.

In the figure, 1 is a semiconductor laser chip, 2 is a diamond heat sink, 3 is a copper heat sink, 4 is a stem, and 5
1 is a lead terminal, 6 is a gold wire, 7 is an optical fiber, 8 is a sleeve, and 9 is a holder.

The assembly of this semiconductor light emitting device is performed as follows.

That is, the laser chip 1 disposed on the diamond heat sink 2 is fixed on the copper heat sink 3 fixed on the stem 4, and the gold wire 6 connects the laser chip 1 and the lead terminals 5.

On the other hand, the optical fiber 7 whose side surface is metallized is inserted into the sleeve 8 fixed to the holder 9 and fixed by soldering.

In the next step, the laser chip 1 is made to emit light, the outer end of the optical fiber 7 is connected to the measuring device, and the boulder 9 is moved vertically and horizontally facing the copper heat sink 3 so that the luminous flux entering the optical fiber 7 is maximized. That is, optical fiber: '7
The position where the laser chip 1 is aligned with the laser chip 1 is detected. The holder 9 is fixed to the copper heat sink 3 by soldering while maintaining this position.

Generally, in a semiconductor light emitting device, in order to suppress a rise in temperature of a light emitting element such as a laser chip 1, the light emitting element is disposed on a heat sink 3 having a high thermal conductivity as in the above example. Furthermore, as described above, in order to suppress coupling loss, it is desirable that the optical component that receives the laser beam, such as the optical fiber 7 in the above example, be placed as close to the laser chip 1 as possible. As a result, a structure in which the holder 9 is soldered to the heat sink 3 as in the embodiment described above is often used.

However, since this soldering is carried out on the heat sink 3, which has a high thermal conductivity, it is difficult to heat the soldering in a limited manner near the part, and it is difficult to reach a sufficient temperature by local heating. If the temperature reaches a temperature sufficient for attaching the light emitting element, the temperature will increase to the light emitting element.

In this soldering process, it is desirable to continue emitting laser light during the soldering process to monitor the alignment of the optical parts, but currently the ambient temperature needs to be around 50 (C) or less to enable continuous laser oscillation. It is. However, the soldering temperature, even for indium-tin (In-8n)-based solder, which has a low melting point, is about 120 to 130 degrees Celsius or higher, making it difficult to continuously monitor oscillation. .

Therefore, after optically aligning the positions of the semiconductor light emitting element and the optical components disposed close to it, it is possible to perform soldering while continuing oscillation and ensuring alignment.
It is desired to develop a method for assembling semiconductor light emitting devices.

(e) Purpose of the Invention The present invention provides a semiconductor light emitting device disposed on a heat sink,
Regarding a semiconductor light emitting device having a structure in which the position of an optical component is aligned with the light emitting element by an optical method and a support for the optical component is fixed to the sheet sink by heat treatment, the temperature of the light emitting element is increased by the heat treatment. It is an object of the present invention to provide a method for assembling a semiconductor light emitting device in which the alignment is suppressed and the alignment can be continuously confirmed optically.

(d) Structure of the Invention The object of the present invention is to provide a semiconductor light emitting device having the above structure in advance by disposing a heat shield plate in a region of the heat sink where the support is fixed, and to perform the heat treatment using energy. This is accomplished by radiation irradiation.

(e) Embodiments of the Invention The present invention will now be described in detail by way of embodiments with reference to the drawings.

FIGS. 2(a) to 2(e) are cross-sectional views showing an embodiment of a semiconductor light emitting device incorporating the optical fiber of the present invention, and the same reference numerals as in FIG. 1 indicate the same target parts.

Referring to FIG. 2(a), a semiconductor laser chip 1 is fixed onto a diamond heat sink 2 using, for example, gold (Au) solder. At this time, it is desirable to place the light emitting surface of the laser chip 1 near an extended surface of one side of the diamond heat sink 2.

Refer to FIG. 2(b) Thermal shield 8i11, which is one of the features of the present invention. Copper heat sink 3. The stem 4 and lead terminals 5 are assembled in advance as shown. The parts are bonded together using, for example, silver solder.

The heat shield plate 11 is made of a material having a lower thermal conductivity than copper (Cu),
For example, iron (Fe), nickel (Ni), titanium (Ti)
metals such as stainless steel, alloys such as invar, aluminum oxide (Mlos), titanium oxide (TiOx), etc.
A root having a thickness of, for example, o, sc + + + ms) to 3 [■] is formed using ceramic made of silicon dioxide (Sin), quartz glass made of silicon dioxide (Sin, ), etc., and is formed on the mounting surface of the diamond heat sink 2 of the copper heat sink 3. On the other hand, it is desirable that the protrusion does not exceed the thickness of the diamond heat sink 2.

FIG. 2(c) The optical fiber 7 whose side surface is meta-hardened with chromium (Cr)-gold (Au), for example, is inserted into the sleeve 8 assembled in the reference holder 9' and soldered with gold (Au)-based solder. Fix it by etc.

In the holder 9' used in this embodiment, a hole 13 is previously provided below the sleeve 8 and passes through the sleeve 8, as shown in the figure. Furthermore, it is desirable that this holder 9 be made of a material with low thermal conductivity similar to that of the heat shield plate 11.

Refer to FIG. 2(d). The semiconductor light emitting device of this embodiment is assembled as described below using the subassemblies described above.

First, the diamond heat sink 2 to which the semiconductor laser chip 1 is attached is placed on a copper heat sink 3 as shown in the figure.
) Fix with solder, etc.

At this time, if the heat shield plate 11 protrudes slightly as described above, its positioning can be easily performed by pressing the end face of the diamond heat sink 2 onto the heat shield plate 11. Next, the semiconductor laser chip 1 is attached using the gold wire 6.
and the lead terminal 5 are connected.

Next, a current is passed through the semiconductor laser chip 1 to bring it into oscillation, while a measuring device is connected to the external extraction side of the optical fiber 7, and the holder 9' is placed on the heating plate 11 as shown in the figure.
The holder 9' is shifted back and forth and left and right to find a position where the optical axis of the optical fiber 7 aligns with the light emitting surface of the semiconductor laser chip 10 and the light output is maximized.

With the semiconductor laser chip 1 and the optical fiber 7 in the aligned position, the solder ball 14 previously loaded in the hole 13 of the holder 9' is irradiated with an energy beam, for example, at an output of 100 to 300 (W). 0.1 to 1 of YAG (yttrium aluminum garnet) laser light
The holder 9' is melted by irradiation for about 0 seconds, and the holder 9' is fixed to the heat shield plate 11. However, this step is performed in an inert gas (eg N, -gas) atmosphere.

Note that it is also possible to select a laser beam other than YAG, a light beam other than a laser beam, a W magnetic wave for optical removal, etc. as the energy beam to be irradiated, and the heat shield plate 11. Holder 9'
Depending on the material, shape, etc., the irradiation rate time may be, for example, 30
It is also possible to extend the time to about seconds.

In this embodiment, due to the heat shield plate 11, the heating range being limited, and the heating time being shortened,
The temperature of the semiconductor laser chip 1 does not reach 50 (°C), and the positional alignment can be continuously monitored without stopping light emission even during heat treatment, and the heat treatment itself is short. In addition, positional displacement during heat treatment was prevented.

Refer to FIG. 2(e) As explained above, after the internal assembly is completed, the cap 1
5 is attached and sealed, the assembly of the semiconductor light emitting device is completed.

Although the above embodiment is an example in which an optical fiber is incorporated, the present invention is not limited to the assembly of a semiconductor light emitting device incorporating an optical fiber. For example, a lens may be installed as a coupling optical system near a semiconductor laser chip. In the structure in which the laser beam is arranged as a parallel beam, the lens holder can be fixed on the heat shield plate by the energy beam shield 1 in the same manner as in the above example.

Furthermore, although the heat treatment using the energy beam on the t/(stream side) melts the solder, the present invention can also be applied to an adhesion method that heats and hardens the resin adhesive.

(f) Effects of the Invention According to the present invention, as explained above, the light emitting element of an optical component disposed close to a semiconductor light emitting element is improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional example of a semiconductor light emitting device, and FIGS. 2(a) to 2(e) are sectional views showing an embodiment of the present invention. In the figure, 1 is a semiconductor laser chip, 3 is a copper heat sink, 7 is an optical fiber, 9 and 9' are holders, and 11 is a heat shield plate. Child 2' figure

Claims (1)

[Claims] When a semiconductor light emitting element is disposed on a heat sink, the position of an optical component is aligned with the light emitting element by an optical method, and a support for the optical component is fixed to the heat sink by heat treatment, the support for the heat sink is 1. A method for assembling a semiconductor light emitting device, characterized in that a heat shield plate is disposed in advance in a region to be identified, and the heat treatment is performed by irradiating energy beams.