JPS61173205A - Fixing method of optical coupling part - Google Patents

Abstract

PURPOSE:To prevent a block where an optical fiber is mounted from slanting and to eliminate a decrease in optical coupling by reflecting laser light projected from above a package horizontally nearly at right angles and soldering and fixing not only top surfaces, but also flanks of a base where a semiconductor element and the block. CONSTITUTION:While the block 10 is held, solder foil 11 is placed straddling on the top surface of the base 30 and the top surface 10A of the block and fused by being irradiated with laser light from above to solder and fix the top surface 10A of the block and the top surface part of the base 30 together. In this case, the fused solder penetrates the gap between the block 10 and base 30 and then this gap part is soldered. Further, solder foil 12 is adhered temporarily straddling on the blank of the base 30 and the flank 10B of the block by using an adhesive, etc. Then, a reflection mirror 15 is placed on the slanting surface of a slanting internal wall 14 and the laser light is projected on the reflection mirror 15 from above the package 14 and reflected horizontally to irradiate the solder foil 12, which is fused to solder and fix the flank 10B of the block and the flank part of the base together.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a method of fixing an optical coupling unit, particularly a block on which an optical fiber is mounted, and a base on which an optical semiconductor element is mounted.

In recent years, when optically coupling an optical semiconductor element such as a laser diode with an optical fiber, the light emitting surface of the optical semiconductor element and the end face of the optical fiber are brought close together (for example, 50 μm) without using a lens or the like. Measures are widely implemented.

At this time, there is a need for a fixing method that reliably maintains the state after adjusting the relative position between the optical semiconductor element and the optical fiber so that the degree of optical coupling between the optical semiconductor element and the optical fiber is high.

[Conventional technology]

FIG. 3 is a perspective view showing a conventional method of fixing an optical coupling part, in which a fixing base 8 is provided protrudingly on the center line of the top surface of a rectangular block 10 made of a metal material. The end portion of the optical fiber 2 is inserted into the groove (for example, a square groove, a square groove, etc.) 9, and is fixed, for example, by soldering.

On the bottom plate 5 of the box-shaped package 4 made of metal material,
A base 3 made of a rectangular metal material is provided with a space between it and one side wall 6 of the package 4 into which the block 10 is inserted.

The optical semiconductor element 1 is mounted on the upper surface of the base 3 in a side gap facing the side wall 6. Incidentally, the side wall 6 is provided with a hole 7 for introducing the optical fiber 2 into the package 4.

The conventional method of fixing the block 1° on which the optical fiber 2 is mounted to the base 3 on which the optical semiconductor element 1 is mounted is to hold the block 10 with a robot hand or the like, for example.
The position of the block 10 is adjusted so that the end face of the optical fiber 2 is brought close to the light emitting surface of the optical semiconductor element 1 and the degree of optical coupling between the optical semiconductor element 1 and the optical fiber 2 is maximized.

Note that there is naturally a small gap between the opposing surfaces of the block 10 and the base 3, and there is also a gap between the bottom surface of the block 1o and the bottom plate 5 of the package 4.

Then, while holding the block 1o, solder foil 1
1 is placed so as to straddle the upper surface of the base 3 and the upper surface of the block 108, and a laser beam is irradiated from above to melt the foil 11 and solder the block 1o and the base 3. Fixed.

Since this method uses a laser beam to melt and fix the solder foil, the base 3 and the block 10 are only partially heated to a low temperature at which the solder foil melts. Therefore, there is no fear that thermal distortion will occur after the base 3 and block 10 are cooled, and even if the block IO is released, the initial optical coupling state is maintained.

[Problem that the invention attempts to solve]

However, in the conventional fixing method described above, the block is fixed to the base only at its upper surface portion, so the bending strength of the solder-fixed portion is not sufficient. Therefore, when a downward or upward force is applied to the block, the block 10 tilts,
There is a problem that the degree of optical coupling decreases.

[Means for solving problems]

The problem with the conventional method is that a laser beam is irradiated from above on the solder foil that spans the top surface of the block on which the optical fiber is mounted and the top surface of the base on which the optical semiconductor element is mounted, and the top surface portion is soldered. Further, a laser beam is projected from above onto the inclined inner wall surface of the package, reflected by the inclined inner wall surface, and irradiated onto the solder foil temporarily placed so as to straddle the side surface of the block and the side surface of the base, This problem is solved by the fixing method of the present invention, in which the side portions are soldered.

[Effect]

According to the above means of the present invention, the side walls on both sides of the package that accommodates the base on which the optical semiconductor element is mounted and the block on which the optical fiber is mounted are formed into inclined inner walls, and a reflecting mirror is placed on the inclined inner wall surface, or Alternatively, by forming a silver film, etc., the laser beam projected from above the open package can be reflected in the horizontal direction at approximately right angles.

Therefore, by temporarily placing solder foil across the side of the block and the side of the base, and irradiating this solder foil with a laser beam, the base and block will be soldered not only on the top surface but also on the side surface. can do.

Therefore, even if a bending force is applied to the block, the block will not tilt, and there is no fear that optical coupling will deteriorate.

〔Example〕

The present invention will be specifically explained below with reference to illustrated examples. Note that the same reference numerals indicate the same objects throughout the figures.

FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG. 2 is a front sectional view.

In FIGS. 1 and 2, a square base 30 made of a metal material is placed on the bottom plate 5 of a box-shaped package 4 made of a metal material, and a block 10 is placed between it and one side wall 6 of the package 4. A space for insertion is provided, and side walls on both sides of the base 30 are formed into inclined inner walls 14 that are inclined upward at approximately 45 degrees.

The optical semiconductor element 1 is mounted on the upper surface of the base 30 in a side gap facing the side wall 6 .

The block 10 is held on the end surface side of the base 30 with a robot hand or the like, and the end surface of the optical fiber 2 is brought close to the light emitting surface of the optical semiconductor element 1, so that the light between the optical semiconductor element 1 and the optical fiber 2 is The position of the block 10 is adjusted so that the degree of coupling is in the best condition.

Then, while holding the block 10, solder foil I
I is placed so as to straddle the upper surface of the base 30 and the upper surface of the block 10A, and the solder foil 11 is melted by irradiating the laser beam from above to solder the upper surface of the block 108 and the upper surface of the base 30. Fix it. At this time, the molten solder penetrates into the gap between the pro 10 and the base 30, so that this gap is also soldered.

On the other hand, in advance, solder foil 12 is temporarily bonded to the side surface of the base 30 with an adhesive or the like so as to span the side surface of the base 30 and the block side surface 10B. A reflecting mirror 15 is mounted on the slope of the inclined inner wall 14.
, and the laser beam is applied to the reflecting mirror 15 from above the package 4.
It is reflected in the horizontal direction and irradiated onto the solder foil 12, melting the half-Bl foil 12 and fixing the block side surface 10B and the side surface portion of the base 30 by soldering. Note that the base 30. If the surface of the block 10 is metalized with a gold film or the like, the adhesion of solder will be good.

As described above, the base 30 and the block 10 are fixed at their respective top and side surfaces, so even if a bending force is applied to the block 10, the block 10 will not tilt.

Therefore, optical coupling does not deteriorate.

〔Effect of the invention〕

As explained above, the present invention reflects laser light projected from above the package horizontally at right angles to the base mounting the optical semiconductor element and the block mounting the optical fiber on the top surface. In addition, by fixing the soldering on the sides, the block will not tilt and the optical coupling will not deteriorate, which is an excellent practical effect.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention, FIG. 2 is a front sectional view, and FIG. 3 is a perspective view showing a conventional method of fixing an optical coupling section. In the figure, 1 is an optical semiconductor element, 2 is an optical fiber, 3.30 is a base, 4 is a package, 8 is a fixing base, 9
is the groove, 10 is the block, 108 is the top surface of the block, 10B
is the side of the block, 11.12 is the solder foil, rod A 0 houses rate 2 days 3 countries

Claims (1)

[Claims] Adjusting either the block on which the optical fiber is mounted or the base on which the optical semiconductor element is mounted, and holding the optical semiconductor element and the optical fiber in alignment so as to achieve a high degree of optical coupling, The solder foil spanning the top surface of the base and the top surface of the block is irradiated with a laser beam from above to solder bond the top surface portion, and further, the laser beam is projected from above onto the slanted inner wall surface of the package to A method for fixing an optical coupling part, characterized in that the irradiation is reflected from an inclined inner wall surface and irradiated onto a solder foil extending over a side surface of the block and a side surface of the base, and the side surface portions are soldered and bonded.