JPS6063981A - Semiconductor light emitting device - Google Patents

Abstract

PURPOSE:To obtain the titled device having a clear radiation surface and good radiating characteristics by a method wherein the photo radiating end surface of a semiconductor light emitting element is provided by projection out of the adhesion end surface between a sub-mount, so that the extra adhesive material oozed out of a heat sink and the light emitting element may not lie over the photo radiating surface. CONSTITUTION:An Si block 2 as a heat sink is provided on a metallic mount 3 which occupies a container or part of the container, and a semiconductor laser element 1 is provided on the heat sink 2 by adhesion with adhering In 5. The photo radiating surface 4 of the element 1 is projected out of the side surface of the heat sink 2 by 1- 30mum. The cavity length of this element is usually 250- 400mum; when the distance (t) of the projected part is less than 1/10 of the cavity length, i.e., less than 40mum, bad influences due to the heat generation of an active region 6 can be ignored, and the effect of heat dissipation is the same as in the case where the element 1 is entirely placed on the heat sink 2. Therefore, the adhesive material In 5 squeezed out at the time of adhesion comes to lie over the element surface having no relation with the laser photo radiating surface or over the back surface, and the radiating surface 4 is kept clean without direct contamination.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a semiconductor light emitting device, and more specifically, to a semiconductor light emitting device with a submount.

[Background of the invention]

Semiconductor light emitting devices, especially semiconductor laser devices.

Due to its small size, light weight, high efficiency, and ease of excitation and modulation, it is considered an important light source for optoelectronics, and has become increasingly important in recent years. In order for this laser device to stably operate continuously at room temperature, it is necessary to lower the oscillation starting current value, provide good heat dissipation, suppress the temperature rise in the active region, and operate at a low operating current.

In order to efficiently dissipate the heat generated in this active region, the active region must be bonded as close as possible to a submount such as a heat sink. for example,
In the case of a typical double heterojunction laser, the active region was located 3-4 μm from the surface of the heat sink. Further, it is desirable that the laser element be bonded approximately at the center of the submount in view of heat dissipation, ease of manufacture, and realization of stable long-term operation. Therefore, of the light emitted with a certain spread angle from the cavity end face of the laser element, the part emitted toward the submount is diffusely reflected by the surface of the submount and is not effectively emitted outside. I can't take it out.

Therefore, one end surface of the submount (heat sink) 2 and one end surface of the laser element 1 as shown in FIG.
A semiconductor light emitting device can be considered in which the semiconductor light emitting device is placed on the substrate and bonded with a molten metal 5 such as In. However, the adhesive metal 5 is
Due to being pressed, it protrudes from the adhesive surface, contaminating the radiation surface 4 of the laser element, and has the drawback of significantly reducing laser efficiency. In the figure, 6 is the active area, and 3 is the holding mouse, which was manually aligned and assembled. Therefore, it takes time to align the elements.

Mass production was not possible.

Incidentally, the following publications are cited as examples of publications showing the positional relationship between the semiconductor light emitting device and the holding member.

For example, JP-A No. 51-126783, Utility Model Application No. 53-10
No. 2382, Utility Model No. 50-150276, Utility Model Application No. 53
-35410, etc.

[Object of the Invention] An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a semiconductor light-emitting device with a sharp emission surface and good radiation characteristics.

[Summary of the invention]

The structure of the present invention for achieving the above object is that the light emitting end face of the semiconductor light emitting element is provided to protrude from the adhesive end face with the submount.

In the present invention, as described above, the light emitting surface protrudes from the heat sink by 1 to 30 μm, so the excess adhesive material protruding between the heat sink and the light emitting element does not cover the light emitting surface. . Therefore, in order to make heat dissipation and current density effective, the above adhesive material can be used sufficiently and interposed on the adhesive surface without any gaps, without causing any inconvenience, and the adhesive material will not contaminate the radiation surface. .

If the light emitting surface and the side surface of the heat sink are approximately on the same plane, it is important to cut out a portion of the heat sink along the adhesive surface. Further, the light emitting surface and one side surface of the heat sink do not necessarily have to be parallel to each other, and the same effect can be obtained as long as they protrude appropriately. If the size of the protrusion of the light emitting element is 1 μm or less, the emitting surface will be contaminated by the adhesive that has protruded. Further, if the thickness is 30 μm or more, the heat generated in the active region will not be sufficiently dissipated, which is not desirable.

Usually, it is best to have the adhesive end surface protrude by 65 to 20 μm.

In the present invention, since the light emitting surface of the light emitting element protrudes as described above, even if the light spreads at a predetermined angle from the spot-like or line-like light emitting area, it will not be reflected on the sub-mount 1 such as the heat sink. It has the advantage of being able to use synchrotron radiation effectively.

In addition to the above-mentioned heat sink, the above-mentioned submount may be used as a reinforcing material for positioning. Of course, it was the same whether it was a part of the mount or the entire mount.It will be described in detail below using an example.

[Embodiments of the invention]

FIG. 2 is a schematic cross-sectional view of a semiconductor light emitting device as an embodiment of the present invention.

A silicon block 2 as a heat sink is provided on a metal mount 3 occupying the container or a part of the container.

The semiconductor laser element 1 is placed on the heat sink 2 with an adhesive I
It is glued with Jz by n5. 2. The light emitting surface (mirror surface) 4 of the laser element 1 protrudes from the side surface of the heat sink 2 by 1 to 30 μm. 6 The cavity length of the laser element is 250 to 406 μm. When the distance between the protruding portions is less than the cavity length of 1710 μm, that is, 40 μm or less, the adverse effects of heat generation in the active region 6 can be ignored. That is, the heat dissipation effect is the same as when all the elements 1 are placed on the pea 1-sink 2. Therefore, the adhesive material (In) 5 that protrudes during bonding will cover the surface (or back surface) of the element unrelated to the laser beam emission surface, and will not directly contaminate the emission surface 4. The other radiation surface is located above the P1-Sink 2, but when the radiation from this surface is used for a monitor or the like, it is adjusted in advance so that there is no fogging of the adhesive. This adjustment is generally accomplished by reducing the amount of adhesive material and gluing the elements from the inside to the outside.

In this example, an n-Ga
l-, Au, As, p-GaAs, p-Ga, -, A
A double heterojunction laser diode 1 of M, As (0≦X<O, S
Place the diode 1 from above on the edge of the upper surface of the heat sink 2, which is 1 square and 1 m thick, with the p side facing the surface of the heat sink 2.
The heat sink 2 was heated to about 200° C. while applying a load of 200° C. to fuse the heat sink 2. The positive electrode was taken from the heat sink 2, and the negative electrode was a gold wire with a diameter of about 100 μm fused to the n-side surface using indium.

This semiconductor light emitting device is assembled in the following manner in order to provide a protruding surface. The assembly equipment required for assembly is shown in FIG. Positioning unit 52 and heating table 51. and a weighted needle 53, and its features are as follows.

]) The angle formed by the alignment surface and the heating table surface is a right angle.

2) The heating surface (the surface on which the heat sink 55 is placed) is θ from the horizontal
It's leaning.

3) In the alignment portion, a thin film 54 with a thickness of 1 to 3 μm is provided as a step at a position lower than the height of the heat sink.

4) A weighted needle is provided to improve the adhesion between the element 56 and the solder on the heat sink 55 after alignment.

Since it has the above-mentioned features, it is an assembly device that fully satisfies the specifications as an assembly device and can be mass-produced.

The above-mentioned assembly device includes 51 heating table, 52 positioning section, 5
Consists of 3 weighted needles, 54 thin films, 51 surfaces and 5
The angle between the faces 2 and 51 is a right angle, and the face 51 is tilted 0 from the horizontal plane. The functions of each part of the GT will be described below.

Heating table: A table on which a heat sink is placed and has a temperature raising mechanism to bond the solder on the heat sink and the light emitting element.

Alignment part: A part that aligns the side of the heat sink and the light emitting surface of the light emitting element in parallel.

Weighted needle: A needle that improves the adhesion between the light emitting element and the heat sink when the solder on the heat sink is melted.

Thin film: A film that prevents the solder on the heat sink from welding to the light emitting surface of the light emitting element during bonding.

The method for manufacturing this assembly device will be described below.

Heating table: Use AQ as the material, and finish the surface in contact with '11% and the surface on which the heat sink is placed to be flat.

Alignment part: AQ is used as the material, and the surface on which the thin film j is formed is finished to be a flat surface.

Weld the alumel-chromel wire to the stainless steel bar with the weighted needle.

Thin film: CrR4 and AQ layers are sequentially formed on the alignment part to a film thickness of 1000-1500 prn and 1-30 prn, respectively. Note that the height of the thin film is set to be 2 to 100 μm lower than the height of the heat sink.

Fix the heating part and positioning part manufactured as above with screws.

The actual procedure for assembling a light emitting device using this assembly device will be described below.

i) Place a heat sink on which AuSn solder is deposited to a thickness of 2 μm on a heating table.

i) Place the light emitting element on the heat sink so that the light emitting surface is flush with the first alignment part. At this stage, the side surface of the heat sink and the light emitting surface become parallel due to the weight of the light emitting element itself.

ii) Raising the temperature of the heater in the heating section and bonding the light emitting element to the heat sink. When the AuSn solder melts, a load is applied to the light emitting element using a weight needle.

The advantages of using this assembly device are as follows.

) It is possible to set the light emitting element so that the light emitting surface protrudes from the side surface of the heat sink. Thereby, the solder of the heat sink can be taken out without adhering to the light emitting surface and without disturbing the light emitting pattern.

Therefore, the light emitting surface of the light emitting element and the side surface of the heat sink can be easily aligned in parallel.

・) Since it is possible to place many heat sinks on the heating table, it is highly suitable for mass production.

Especially when the light emitting part is close to the heat sink, i.e. up
- It is effective when assembled with 5 ide down.

FIG. 3 is a schematic sectional view of a semiconductor light emitting device as another embodiment of the present invention.

The side surface of the heat sink 2 and the light emitting surface 4 of the laser element 1 are on the same plane, and the heat sink is cut out in a slope along the adhesive surface. In this case as well, the protruding adhesive material is applied to the cutout portion, so that good laser light can be provided without contaminating the light emitting surface 4. The reference numerals in the drawings are the same as those in FIG. 2 described above, so their description will be omitted. Moreover, FIG. 4 shows a case where the above-mentioned notch portion is cut out in an L-shape (in the drawing). Other parts 1 members, etc. are the same as in FIG. 2. In these embodiments, since the light emitting surface and the heat sink side surface are on the same plane, manufacturing is simplified and the thin film shown in FIG. 5 in the previous embodiments is not necessary.

〔Effect of the invention〕

As detailed above, one aspect of the present invention is that by providing the light emitting surface of the light emitting element to protrude from the adhesive end surface with the submount, the light emitting surface can be kept clean and a light emitting device with good characteristics can be provided. The industrial benefits are huge.

In the above embodiments, a semiconductor laser element is used as the light emitting element, but any element that emits light or emits electromagnetic waves can be easily applied. Further, although an adhesive was used to bond the element and sub-mount 1-, the present invention is applicable and within the scope of rights even if a part of the element or sub-mount 1- is melted and bonded. Those skilled in the art will easily guess this.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a conventional semiconductor light emitting device, FIG. 2 is a schematic sectional view of a semiconductor light emitting device as an embodiment of the present invention, and FIGS. 3 and 4 are as another embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of a semiconductor light emitting device, and FIG. 5 is a schematic perspective view of an assembly apparatus used for manufacturing the present invention. DESCRIPTION OF SYMBOLS 1...Semiconductor light emitting device, 2...Submount (P1-sink), 3...Mount (stem), 4...Light emission device 1 Figure 2

Claims (1)

[Scope of Claims] 1. In a semiconductor light emitting device having at least a semiconductor light emitting element and a holding member for holding the semiconductor light emitting element, at least one light emitting end surface of the semiconductor light emitting element is attached to the light emitting element holding member of the holding member. A semiconductor light emitting device characterized by being provided so as to protrude from a surface. 2. The semiconductor light emitting device 6 according to claim 1, wherein the main surface end of the light emitting element holding surface of the holding portion is not directly connected to the side surface of the holding member.