JPS62150894A - Optical device and manufacture thereof - Google Patents

Abstract

PURPOSE:To absorb the displacement of an optical lens due to the thermal expansion of a material occurring owing to a temperature change by fixing the lens on a base by an elastic force due to the bending of a cap. CONSTITUTION:A cap 2 is attracted to the end of a suction pipe 5 connected with a vacuum pump, and a spherical lens 1 is attracted to the cap 2 side through a hole 2a for positioning the lens. A power source is connected with a semiconductor laser chip 4, a forward current is supplied to emit a light, the attracted lens 1 is positioned, the pipe 5 is then moved downward, pressure is applied to the cap 2 to elastically deform it, thereby contacting the cap with a base 3. A current is supplied from the cap 2 to the base in this state to secure the cap 2 to the base 3 by resistance heating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optical device used in optical fiber communication and a method for manufacturing the same.

[Technical background of the invention and its problems]

In order to realize optical fiber communication, it is important to connect optical fibers and semiconductor optical devices stably and with high efficiency. Among these, a structure as shown in FIG. 4 has been conventionally adopted for fixing an optical lens having a light condensing and collimating function. In other words, the spherical lens α1) is fixed to the base IJI on which the optical semiconductor is fixed in the holder (l) held inside the hole opened in the optical axis direction. Although it is possible to fix the lens with a highly durable metal, it is asymmetrical as a part of the fixing surface is soldered (f), and has the disadvantage that thermal expansion caused by temperature changes can cause the nine-ball lens to shift in position. Especially when there is a single mode fiber in all phases, the fiber core diameter is 1
It is very small, about 0 μm.

Even a slight misalignment of the ball lens has a large effect on the coupling characteristics. In addition, the holes in the ball lens and holder require precise dimensional alignment, which requires high processing accuracy and is expensive. Furthermore, with such a structure, it is difficult to adjust the distance between the ball lens and the optical semiconductor element in the optical axis direction, and during manufacturing, a process of press-fitting the ball lens into the holder is required, which requires soldering. The drawback is that the temperature rise during deposition causes complete deterioration of the optical semiconductor element, resulting in poor yield. If the cap is fixed using the resistance heating method, which causes a small temperature increase due to tint marks, there is a possibility that the single-ball lens will shift in the optical axis direction, and the fixing accuracy will deteriorate.

[Purpose of the invention]

This invention improves the above-mentioned problems, and aims to provide an optical IT with good temperature characteristics, low cost, and high productivity, and a method for manufacturing the same.

[Summary of the invention]

A hole used to position an optical lens at a predetermined position on a base to which an optical semiconductor element is fixed? The optical lens is fixed in a state in which the cap is elastically bent and the optical lens is pressed between it and the base.

Furthermore, the manufacturing method uses the pressure difference when sucking air to attach the cap to the mouthpiece, and then the optical semiconductor element is fixed with the optical lens attached through the entire hole provided in the cap. While installing the optical lens in a predetermined position on the base, the cap is elastically deformed and fixed at the part where it contacts the base by resistance heating, soldering, laser welding, or laser soldering. It can be manufactured by Further, after fixing the cap, solder or molten glass may be poured into the hole provided in the cap to fix the cap and the optical lens to increase the fixing strength.

〔Effect of the invention〕

According to the optical device and the manufacturing method thereof according to the present invention, since the optical lens is fixed on the base by the elastic force caused by bending the cap, the positional shift of the optical lens due to thermal expansion of the material caused by temperature change can be absorbed. can improve reliability. The method of adsorbing the cap and optical lens by creating a specific pressure difference does not make it easy to attach and detach them, but it involves a process of fixing the cap and optical lens, which are the members used for fixing the metal, in advance. I omitted it. As a result, the cap does not require high dimensional accuracy and can be manufactured in a simple manner.

Furthermore, since the cap can be fixed by resistance heating without causing any displacement of the lens when fixing the cap, it is possible to prevent deterioration of the optical semiconductor element due to heat and improve yield.

[Embodiments of the invention]

A first embodiment of the present invention will be described in the case where a semiconductor laser is used as an optical semiconductor element and a ball lens is used as an optical lens.
This will be explained in detail using figures. In the figure, (1) is a ball lens, (2) is a cap, 13) is a base, and (4) is a semiconductor laser chip. The cap (2) and the ball lens (1) are connected to each other by contacting the ball lens on the circumference of the hole (2a) provided in the cap (2) and having a diameter smaller than the diameter of the round ball lens.
The ball lens (1) is placed on the base (3) on which the semiconductor laser chip (4) is placed.
) is fixed by the elastic force caused by the deformation of

Here, the cap (2) is in a deformed state iη and the base (3) is
is fixed to. According to this structure, two-ball lens (1)
By simply changing the distance between the semiconductor chip and the chip, the same manufacturing component can be used for both light collection and collimation.

The diameter of the hole drilled in the cap only needs to be smaller than that of the spherical lens, and there is no need to match each other's dimensions as in the case of fitting, and high processing accuracy is not required for the external dimensions, so press processing is used. It can be manufactured using similar methods, and is inexpensive when mass-produced. In addition, since the light-emitting surface of the semiconductor laser chip is spatially separated from the optical lens, the semiconductor laser chip does not deteriorate as would occur if it were directly fixed to the light-emitting surface with adhesive. It can be used without damaging the first characteristic.

FIG. 2 shows an example of the process for manufacturing this structure. 1st
In the process (see figure (a)), the cap (2) is first fully adsorbed on the tip of the suction pipe (5) connected to the vacuum pump, and then the bulb is inserted through the lens positioning hole (2a). Attach the lens (1) to the inside of the cap (2).

In the second step (see (b) in the same figure), the laser chip is soldered to the base (3) so that it can be printed, and the semiconductor laser chip with the lead a (6) is connected to the power supply (7). All connections are made, and a forward current is applied to make the bulbs emit light and the attached bulbs (1) are brought close to the light emitting part on the base. The inside dimensions of the cap should be long enough so that only the ball lens touches the base. Then, while monitoring the laser light that has completely passed through the ball lens (1), the positions of the ball lens (1) and the base (3) are mutually changed to find the optimum position. In the third step (see figure (b)), the suction pipe (5) is moved downward at the optimum position, pressure is applied to the cap (2), the cap (2) is elastically deformed, and the base (3) is moved downward.
). Cap (2) in this state
The cap (2) is heated by resistance heating by passing a current through the base.
and the base (3) are completely fixed. Soldering, laser welding, and laser soldering methods are also used for fixing. Furthermore, solder to the positioning hole (2a).

If all the light enters the molten glass, it will be a one-ball lens (1) and a cap (
2) The fixing strength can be increased. According to this manufacturing method, the ball lens is fixed while positioning in two positions, so it is possible to fix the ball lens with high precision.The ball lens is fixed by the elastic force of the cap, so the temperature characteristics are good, and when it is fixed, A resistance heating method that involves displacement of the member but allows local heating can be used. Also adsorption pipe (5)
Since the electrode for resistance heating and the effecting body for applying pressure can also be used, manufacturing jigs can be easily created.

Using a vacuum for suction has the advantage that it is easy to attach and detach the cap and lens, making it highly workable.

Further, another embodiment of the present invention is shown in FIG. When the rod lens (8) is used as an optical lens, the cap (9)
) is provided with a groove (9a) for positioning the rod lens (8) and a hole (9b) used as a suction port. By providing the groove in the cap in this way, optical lenses other than 9-ball lenses can be fixed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of an optical lens fixing structure according to the present invention. FIG. 2 is a diagram showing one embodiment of the method for manufacturing an optical lens fixing structure according to the present invention, FIG. 3 is a diagram showing another embodiment of the present invention, and FIG. 4 is a diagram showing a conventional example. 1... Ball lens, 2, 9... Cap, 2a.
... Hole provided in the cap, 3... Base, 4...
Semiconductor laser chip, 5... Suction pipe, 6... Lead wire, 7... Power supply. 8... Rod lens, 9a... Groove provided in the cap. Agent Patent Attorney Noriyuki Chika Yudo Kikuo Takehana Figure 1? (0,) Figure 2' (b) Figure g2 Figure 4

Claims (7)

[Claims] (1) A base, an optical semiconductor element, an optical lens installed at a predetermined position on the base, and a cap having a hole or groove used for positioning the optical lens, and the cap has an elastic An optical device, characterized in that the optical device is fixed to the base in a state in which the optical lens is bent and pressed down. (2) The optical device according to claim 1, wherein the cap and the optical lens are fixed to each other. (3) The optical device according to claim 1, wherein the optical semiconductor element is a semiconductor light emitting element or a semiconductor light receiving element. (4) While positioning the optical lens while adsorbing the optical lens through the cap and the hole provided in the cap, elastically deforming the cap and fixing it on the base on which the optical semiconductor element is fixed. A method for manufacturing an optical device characterized by: (5) The method for manufacturing an optical device according to claim 4, wherein the cap and the optical lens are attracted to each other by suctioning air. (6) The method of manufacturing an optical device according to claim 4, wherein the cap is fixed by any one of resistance heating, soldering, laser welding, and laser soldering. (7) The method for manufacturing an optical device according to claim 4, wherein the cap and the optical lens are fixed together by soldering or fused silica after the cap and the base are fixed. .