JPH0933768A - Optical semiconductor device - Google Patents

Abstract

(57) Abstract: An optical semiconductor device provided with a plastic lens that can be welded and fixed with high reliability is provided. SOLUTION: A donut-shaped metal disk 18 having an inner diameter larger than the lens and an outer diameter larger than the flange portion is brought into close contact with a plastic lens 2 having a disk-shaped flange portion, and a protrusion provided on the inner diameter portion of the metal disk 18 is made of plastic. The plastic lens 2 and the metal disk 18 are integrated by being fitted to the flange portion of the lens 2. The holder 3 and the semiconductor light emitting element 1, the holder 3 and the ring 5, and the ring 5 and the receptacle 7 are fixed by welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor device for optical fiber communication, which collects light emitted from a semiconductor light emitting element and guides it to an optical fiber.

[0002]

2. Description of the Related Art In an optical semiconductor device for optical fiber communication, which collects light emitted from a semiconductor light emitting element and guides it to an optical fiber, the optical coupling technique is improved and the configuration is simplified.
Reliable lens fixing method has become an important issue.

In the conventional optical semiconductor device shown in FIG. 9, for example, the optical semiconductor device proposed in Japanese Patent Laid-Open No. 3-233415, a semiconductor light emitting element 1 having a laser diode built therein is provided.
Is assembled in the cap-shaped holder 3 together with the lens 2. Since the lens 2 is made of glass and has a rod shape, the side surface is metal-plated and fixed by soldering. A ring 5 is inserted and fixed to the cylindrical portion of the upper edge 4 of the holder 3, and the ring 5 has a hole 6 for passing the focused light. A receptacle 7 is arranged on the ring 5, and the receptacle 7 has a hole 8 for passing the focused light and a hole 10 for inserting a ferrule 9, and the center of the ferrule 9 inserted in the hole 10. One end of the optical fiber 11 is inserted and fixed to the shaft. That is, the semiconductor light emitting device 1
The light emitted from the lens is focused by the lens 2, and the focused light is given to the light receiving surface of the optical fiber 11.

To assemble such an optical semiconductor device, the semiconductor light emitting element 1 and the lens 2 are assembled in the holder 3, the ferrule 9 into which the optical fiber 11 is inserted and fixed is inserted into the hole 10 of the receptacle 7, and the holder 3 is inserted. The upper edge 4 is inserted into the tubular portion 12 at one edge of the ring 5. Then, after the position adjustment for relatively moving the holder 3 and the ring 5 in the axial direction, they are laser-welded at the joint portion 13. Further, the ring 5 and the receptacle 7 are laser-welded at the joint portion 14 after the position adjustment for relatively moving the ring 5 and the receptacle 7 is performed. The stopper 16 fixes the receptacle 7 with a screw.

[0005]

However, in the conventional optical semiconductor device described above, the lens 2 is fixed to the holder 3 by soldering. When a high-performance, inexpensive plastic lens developed in recent years is fixed by soldering, the heat resistance temperature is 1
Since it is as low as 50 ° C. or lower, it melts or deforms, so that it is difficult to fix it with solder. Further, when using an adhesive, there is a problem that it is easy to peel off in an environment with high humidity.

An object of the present invention is to provide an optical semiconductor device in which a lens is fixed with high reliability even in a high humidity environment in order to solve the above conventional problems.

[0007]

In order to achieve the above-mentioned object, a first optical semiconductor device of the present invention has a lens for collecting light emitted from a semiconductor light emitting element and coupling it with an optical fiber. An optical semiconductor device comprising a semiconductor light emitting element and a light emitting element having a disk-shaped base, a cylindrical holder having a central axis aligned with the light emitting element, and a tip end portion of the holder. An optical semiconductor provided with a plastic lens, a cylindrical ring fitted to the holder, and a receptacle having a through hole for inserting a ferrule having an optical fiber fixed in the center and having the central axis aligned with the ring. In the device, the lens has a flange portion,
A donut-shaped metal disk is crimped onto the flange portion, and the metal disk and the holder are welded and fixed to each other. Here, the flange portion of the lens means a flat surface provided on the outer peripheral edge of both surfaces of the lens excluding the side surface of the convex lens. Further, the convex portion other than the flange portion of the lens is referred to as a lens portion. In the above structure, it is preferable that the holder and the light emitting element are fixed to each other by welding. Further, in the above configuration, it is preferable that the inner diameter of the metal disc is larger than the outer diameter of the lens portion of the lens, and the outer diameter of the metal disc is larger than the outer diameter of the flange portion of the lens. Further, in the above configuration, it is preferable that the donut-shaped metal disk includes a substantially vertical protrusion around the inner diameter, and the protrusion is fitted to the flange portion of the lens. Further, in the above structure, it is preferable that the flange portion of the lens is held by being sandwiched between the donut-shaped metal disk and the holder. Further, in the above-mentioned configuration, it is preferable that the ring has a protrusion for positioning the ferrule inserted in the receptacle.

Next, a second optical semiconductor device of the present invention is an optical semiconductor device for condensing light emitted from a semiconductor light emitting element with a lens and coupling it to an optical fiber. A light emitting element having a disk-shaped base, a cylindrical holder provided with the central axis coinciding with the light emitting element, a plastic lens provided at the tip of the holder, and a cylindrical ring fitted to the holder. In an optical semiconductor device having a through hole for inserting a ferrule having an optical fiber fixed in the center and a receptacle provided with the center axis aligned with the ring, the semiconductor light emitting element has a heat dissipation stem. The inner wall of the end portion of the holder has an inclined surface for fixing to the semiconductor light emitting device. Here, the heat dissipation stem means a lid made of a disc-shaped metal on which a semiconductor light emitting element is mounted and held. The through hole provided in the receptacle may be simplified to a single through hole.

In the above structure, the side surface of the plastic lens has an uneven portion, and the inner wall of the holder has an uneven portion,
It is preferable that the plastic lens is fixed to the holder by fitting the uneven portion of the plastic lens and the uneven portion of the holder. The plastic lens is preferably fixed in the holder by molding.

Further, in the above structure, it is preferable that the holder, the ring and the receptacle are made of metal, the holder and the ring are fixed to each other by welding, and the ring and the receptacle are fixed to each other by welding.

Further, in the above structure, it is preferable that the ring has a projection for positioning the ferrule inserted in the receptacle. In the above configuration,
It is preferable that the holder and the heat radiation stem of the semiconductor light emitting element are fixed to each other by welding.

Further, in the above structure, it is preferable to provide a recess for positioning and accommodating the optical semiconductor device on the outer periphery of the ring. A recess may be provided on the outer peripheral portion of the holder.

In the above structure, it is preferable that the receptacle and the ring have surfaces contacting each other in a direction perpendicular to the optical axis, and the holder and the ring have surfaces contacting each other in a direction parallel to the optical axis.

Further, in the above-mentioned structure, it is preferable that the receptacle is a sintered body obtained by molding and baking metal powder containing iron. Next, a third optical semiconductor device of the present invention is an optical semiconductor device for condensing light emitted from a semiconductor light emitting element with a lens and coupling with an optical fiber, and a disc-shaped stem having a protrusion in the center, A semiconductor light emitting element provided on the side surface of the projection for emitting light in the tip direction of the projection, a plastic lens provided at the tip of the projection with the optical axis aligned with the semiconductor light emitting element, and at the tip. A cylindrical protective cap which has a transparent flat plate and covers the lens and the semiconductor light emitting element and whose end is in contact with the stem, and a through hole for inserting a ferrule with an optical fiber fixed in the center It is characterized in that the protective cap is provided with a receptacle provided with its central axis aligned with each other, and the light emitted from the semiconductor light emitting element is condensed by the lens on the front end surface of the protective cap. In the above structure, the protrusion is preferably a prism. Further, in the above structure, it is preferable that the transparent flat plate is formed of a flat plate lens, and the light emitted from the semiconductor light emitting element is condensed on the tip surface of the flat plate lens. Further, in the above structure, it is preferable that the lens is adhesively fixed to the inner wall of the protective cap.

In the first configuration of the present invention,
It is preferable that the outer circumference of a part of the through hole of the receptacle is smaller than the outer circumference of the other part of the through hole. Further, in the above-mentioned configuration, it is preferable that the receptacle is a sintered body obtained by molding and baking metal powder.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the configuration of the first semiconductor device of the present invention, there is provided an optical semiconductor device for condensing light emitted from a semiconductor light emitting element with a lens and coupling it with an optical fiber. A light emitting element having a disk-shaped substrate with a built-in semiconductor light emitting element, a cylindrical holder provided with the central axis coinciding with the light emitting element, a plastic lens provided at the tip of the holder, and the holder. In an optical semiconductor device comprising a fitted cylindrical ring and a receptacle provided with a through hole for inserting a ferrule having an optical fiber fixed in the center and having the central axis aligned with the ring, the lens is a flange. Since the metal disk and the holder are welded and fixed to each other, the donut-shaped metal disk having a portion is crimped to the flange portion, and thus the highly reliable recording disk is provided even in a high humidity environment. The optical semiconductor device can be achieved which can's fixed.

Further, according to the preferable example of the present invention in which the holder and the light emitting element are fixed to each other by welding, the central axes of the light emitting element and the holder can be surely aligned with each other. Further, according to the preferable example of the present invention in which the inner diameter of the metal disk is larger than the outer diameter of the lens portion of the lens, and the outer diameter of the metal disk is larger than the outer diameter of the flange portion of the lens, the lens can be easily and reliably placed in the holder. Can be fixed.

According to a preferred embodiment of the present invention, the donut-shaped metal disk is provided with substantially vertical protrusions around the inner diameter, and the protrusions are fitted to the flange portion of the lens.
The lens is firmly fixed without coming off the metal disk.

Further, according to the preferable example of the present invention in which the flange portion of the lens is held by being sandwiched between the donut-shaped metal disk and the holder, the lens and the holder are more securely fixed. Also, according to the preferable example of the present invention in which the ring has the protrusion for positioning the ferrule inserted into the receptacle, the specific number of parts for positioning the ferrule is not required, and the number of parts can be reduced.

Next, according to a second optical semiconductor device of the present invention, there is provided an optical semiconductor device for collecting the light emitted from the semiconductor light emitting element by a lens and coupling it with an optical fiber. A light-emitting element having a disk-shaped base with a built-in, a cylindrical holder provided with the central axis coinciding with the light-emitting element, a plastic lens provided at the tip of the holder, and a cylindrical shape fitted to the holder In an optical semiconductor device including a ring and a receptacle having a through hole for inserting a ferrule having an optical fiber fixed in the center and having the central axis aligned with the ring, the semiconductor light emitting element has a heat dissipation stem. By having the inclined surface for fixing to the semiconductor light emitting element on the inner wall of the end portion of the holder, an optical semiconductor device with high coupling efficiency with the optical fiber can be achieved. That is, by not contacting the inclined surface and the end of the protective cap that covers the semiconductor light emitting element, the holder can be more stably fixed to the light emitting element, and highly reliable lens fixing is possible even in a high humidity environment. Optical semiconductor device can be achieved.

The side surface of the plastic lens has an uneven portion, the inner wall of the holder has an uneven portion, and the uneven portion of the plastic lens and the uneven portion of the holder are fitted together to fix the plastic lens to the holder. According to the preferred embodiment of the present invention, the plastic lens is firmly fixed to the holder.

Further, according to the preferable example of the present invention in which the holder, the ring and the receptacle are made of metal, the holder and the ring are welded and fixed to each other, and the ring and the receptacle are welded and fixed to each other, the respective parts can be securely connected. Can be fixed. According to the preferable example of the present invention in which the holder and the heat radiation stem of the semiconductor light emitting element are fixed to each other by welding, the holder and the semiconductor light emitting element can be fixed more reliably.

According to a preferred example of the present invention in which a recess for positioning and accommodating the optical semiconductor device is provided on the outer periphery of the ring, the optical semiconductor device can be easily positioned in the case.

According to a preferred embodiment of the present invention, the receptacle and the ring have surfaces contacting each other in the direction perpendicular to the optical axis, and the holder and the ring have surfaces contacting each other in the direction parallel to the optical axis. It becomes easy to adjust the position.

Further, according to a preferred example of the present invention in which the receptacle is a sintered body obtained by molding and baking metal powder containing iron, the variations in the shape of the receptacle are eliminated.
Product reliability is stable. Further, the welding characteristics can be improved.

Further, if the hole of the receptacle is simplified to a single through hole, it can be manufactured by a mass production method such as powder metallurgy, and further, dimensional variation of parts can be reduced and cost can be reduced.

Next, according to the third optical semiconductor device of the present invention, in the optical semiconductor device for collecting the light emitted from the semiconductor light emitting element by the lens and coupling it to the optical fiber, a disk having a protrusion in the center is provided. -Shaped stem, a semiconductor light emitting element provided on the side surface of the projection for emitting light toward the tip of the projection, and a plastic provided on the tip of the projection with the optical axis aligned with the semiconductor light emitting element. A lens, a cylindrical protective cap that has a transparent flat plate at the tip and covers the lens and the semiconductor light-emitting element, and the end of which is in contact with the stem, and for inserting a ferrule having an optical fiber fixed in the center And a receptacle having a through hole and having a central axis aligned with the protective cap, wherein the light emitted by the semiconductor light emitting device is condensed by the lens on the tip surface of the protective cap. More, the coupling efficient optical semiconductor device of the optical fiber can be achieved.

According to the preferred embodiment of the present invention in which the protrusion is a prism, the semiconductor light emitting element is provided on one side surface of the prism, so that the position of the light emitting element does not shift. According to a preferred example of the present invention in which the transparent flat plate is composed of a flat plate lens and the light emitted from the semiconductor light emitting element is condensed on the tip surface of the flat plate lens, the light from the light emitting element is emitted regardless of the distance between the lenses. Light is always focused at a fixed position.

Further, according to the preferable example of the present invention in which the lens is adhesively fixed to the inner wall of the protective cap, the lens can be surely fixed. Further, if the outer circumference of a part of the through hole of the receptacle is smaller than the outer circumference of the other part of the through hole, hole processing becomes easy.

[0030]

【Example】

(Embodiment 1) FIG. 1 is a sectional view of an optical semiconductor device of this embodiment.

The light emitting element 1 incorporating the laser diode 1a has a disc-shaped stem 1b. The stem 1b was pressed into one end of the holder 3 and the welded portion 17 was welded and fixed by a YAG laser spot welder. The metal disk 1 is attached to the flange of the plastic lens 2 made of amorphous polyolefin.
8 is fixed. The precision hole 10 of the receptacle 7 is
In order to minimize the positional deviation of the optical fiber 11 at the center of the ferrule 9 to be inserted, the hole diameter tolerance is 3 μm and the length is 7 mm. Actually, it is confirmed that there is no problem in performance even if the length of the precision hole is 4 mm, and the length of the precision hole 10 is set to 4 mm. Shortening the length of the precision hole 10 facilitates drilling. The receptacle 7 is manufactured by cutting stainless steel.

The ferrule 9 is placed in the precision hole 10 of the receptacle 7.
Is inserted and the tip is abutted against the tip 20 of the ring 5. The holder 3 is slid in the axial direction with respect to the ring 5, and the position of the ring 5 is adjusted with respect to the receptacle 7 in the direction perpendicular to the central axis to couple the light collected by the plastic lens 2 to the optical fiber 11. . In this state, the joints 13 and 14 were welded and fixed by a YAG laser spot welder.

FIG. 2 is a view showing the structure of the lens 2 and the metal disk 18 shown in FIG.
(A) is a plan view and (b) is a sectional view. Metal disk 18
Protrusions 19 are provided at four locations on the inside of, and the protrusions 19 are firmly fixed by fitting in the flange portion of the plastic lens 2. Further, since the metal disk 18 is attached when the plastic lens 2 is molded, the metal disk 18 structurally adheres to the plastic lens 2.

When the metal disk 18 is placed in the recess (step) provided on the inner wall of the upper end of the holder 3 in FIG. 1, the central axes of the lens 2 and the holder 3 are aligned. The welded portion 13a was welded and fixed with a YAG laser spot welder.

Since the optical semiconductor device constructed as described above is molded with the metal disk 18 incorporated in the plastic lens 2, the plastic lens 2 and the metal disk 18 are molded.
Adheres structurally. When the metal disk 18 is fixed to the holder 3 by welding, the plastic lens 2 is not displaced or separated, and the plastic lens can be fixed with high reliability. When the metal disk 18 is attached to the lens 2, the metal disk 18 may be heated and pressed against the lens 2 to be in close contact therewith.

Further, since the length of the precision hole 10 of the receptacle 7 is shortened, it is easy to manufacture parts and the yield is increased. Although the metal disk 18 is provided on one side of the flange portion of the plastic lens 2, it may be provided at the center of the flange portion. Further, although the protrusion 19 is provided on the inner diameter portion of the metal disk 18, the protrusion 19 may be located at any position where the flange portion is not easily inserted, and its direction is not particularly limited.

(Embodiment 2) FIG. 3 is a sectional view showing the structure of an optical semiconductor device according to this embodiment. The plastic lens 2 has a flange portion. The hole 21 of the holder 3 has a slightly larger inner diameter than the other portions. When the plastic lens 2 is attached to the holder 3, the flange portion of the plastic lens 2 is stopped by the stopper 23. Donut-shaped press-fitting ring 22 in holder 3
Is press-fitted and the welded portion 13a is welded and fixed by a YAG laser spot welder. The flange portion of the plastic lens 2 is sandwiched between the stopper 23 and the press-fitting ring 22, and the press-fitting ring 22 is welded and fixed to the holder 3, so that the plastic lens 2 does not move.

In this way, the elastic plastic lens 2 can be easily and surely fixed by sandwiching it. (Embodiment 3) FIG. 4 is a sectional view showing the structure of an optical semiconductor device of this embodiment.

The light emitting element 41, which has the laser diode 41a built-in and is sealed with the protective cap 41c, has a disc-shaped stem 41b serving as a heat dissipation plate. An inclined notch is provided on the inner surface of the lower end portion of the holder 43, and a cylindrical short protrusion into which the stem 41b is inserted is provided on the outer periphery thereof (not shown). The stem 41b is press-fitted into one end of the holder 43, and the welded portion 416 is welded and fixed by a YAG laser spot welder.
Since the holder 43 has a notch, the holder 43 and the end of the protective cap 41c do not come into contact with each other, and the holder 43 can be stably fixed to the stem 41. The central axes of the lens 42 provided on the holder 43 and the laser diode 41a are mechanically aligned. A plastic lens 42 made of an amorphous polyolefin excellent in heat resistance (123 ° C.) and humidity resistance (moisture resistance 100 times higher than that of acrylic resin) is manufactured by die molding in a hole provided in the disk portion 418 of the holder 43. To do. Since the projections 419 are provided on the wall surface of the hole of the disc portion 418 to form the irregularities, the molded lens 42 is extremely unlikely to come off.
Further, a shallow dent (step) is provided on the surface of the disk near the hole on the surface of the disk 418, which serves to release excess resin when the lens is molded.

Since the inner diameter of the ring 45 is slightly larger than the outer diameter of the holder 43, both of them move axially in a lubricating manner. Holder 4
Insert 3 into ring 45. A hole 410 of the receptacle 47 is provided at the other end of the ring 45 so as to cover the protrusion 45 a of the ring 45. The optical fiber 411 is inserted and fixed in the center, and the ferrule 49 having a mirror-polished end is attached to the receptacle 47.
Insert into the hole 410. The tip of the ferrule 49 abuts on the protrusion 45a of the ring 45 and is axially positioned.

The holder 43 is axially aligned with the ring 45 so that the light output from the laser diode 41a and condensed by the lens 42 passes through the hole inside the ring 45 and becomes a minimum spot near the hole of the protrusion 45a. Direction, weld 4
Fix 15 with a YAG laser welder. Also, ring 4
5 is moved in a direction perpendicular to the axis with respect to the receptacle 47, and the welding portion 414 is fixed with a YAG laser welding machine at a position where light is incident on the optical fiber 411 in the ferrule 49 inserted into the hole 410 of the receptacle 47.

When the ferrule 49 is attached to or detached from the hole 410 of the receptacle 47, the optical fiber 41 in the hole 410 is removed.
In order to prevent the position of No. 1 from changing, the diameter of the hole 410 is set to be a precision hole larger than the ferrule 49 by only 1 to 3 μm. In order to easily form such a precision hole, the hole 41
0 has a simple single through-hole structure. Further, the receptacle 47 having the hole 410 is manufactured by using the metal mold working method by the powder metallurgy method, and it is possible to manufacture the component with high accuracy and small dimensional variation at low cost. In order to perform optimum welding and fixing, iron powder is the main component in the sintered material,
A metal powder mixed with nickel (9 to 13% by weight) and chromium (18 to 20% by weight) was used to obtain a material equivalent to stainless steel. In this embodiment, Fe: 70% by weight, N
A metal powder of i: 12% by weight and Cr: 18% by weight was used.

Since the hole 410 has a simple single through hole structure, the inserted ferrule 49 is positioned by abutting against the projection 45a provided at the tip of the receptacle 47. The ring 45 is provided with a protrusion 45a to have a positioning function for the ferrule 49, thereby reducing the number of parts.

The holder 43 is also formed by the powder metallurgy method to reduce the variation in shape. At a portion where the receptacle 47 and the ring 45 are in contact with each other, a protrusion is provided on the outer peripheral portion of the receptacle 47, and a notch is provided on the ring 45 side to form the recess 424.
Is configured. By inserting a part of a case accommodating the optical semiconductor device into the recess 424, the optical semiconductor device can be easily positioned in the case.

As described above, the disk portion 418 of the holder 43
It is possible to reduce the number of parts by directly molding the plastic lens 42 having high heat resistance and high humidity resistance into the mold, and also to perform reliable welding and fixing with the plastic lens.

In addition, the ferrule 49 of the receptacle 47
By making the hole 410 for inserting a simple single through hole to improve the dimensional accuracy of the hole, and by using the metal powder metallurgy method with high mass productivity, it is possible to inexpensively manufacture parts with small dimensional variation. did.

Needless to say, the projection 419 may have a groove shape as long as it has irregularities. Also, the recess 424
Is provided near the boundary between the receptacle 47 and the ring 45, but the recess 424 may be provided anywhere provided on the outer peripheral portion of the ring 45.

(Embodiment 4) FIG. 5 is a sectional view showing an optical semiconductor device of this embodiment. In this embodiment, the height of the protective cap 31 is designed to be 2.5 mm in advance. A hole 32 is provided at the tip of the protective cap 31, and a glass plate 33 is bonded so as to close the hole. The laser diode 1a is located on the side surface of the prism 30 provided on the stem 1b at a position of 200 μm from the tip surface (from the stem 1b to 1 m).
Solder to the height (m). Glass substrate thickness is 0.5m
The m Fresnel lens 2 is manufactured by an electronic drawing device.

The semiconductor light emitting device 3 thus constructed
The receptacle 7 having a hole is provided on the tip surface of the protective cap 31 of 6. Insert the ferrule with the optical fiber inserted in the center into the hole, and move the semiconductor light emitting element 36 in the direction perpendicular to the central axis with respect to the receptacle 7 with the tip of the ferrule abutting against the protective cap 31 to adjust the optical axis. Optically couple. When the amount of light incident on the fiber is maximized, the YAG laser spot welder welds and fixes the welded portion 37 to form a semiconductor module.

FIG. 6 is a side view showing the lens mounting portion of FIG. 5 of this embodiment. As shown in FIG. 6, the Fresnel lens surface 35 is fixed to the prism 30 with an acrylic adhesive which is an ultraviolet curable resin so as to face the laser diode 1a. The submount substrate 34 is the laser diode 1
A silicon substrate is used to adjust the height of a and perform reliable solder mounting. Since the distance between the laser diode 1a and the Fresnel lens 2 is about 200 μm, the light is condensed at a position of 0.8 mm from the other end surface of the Fresnel lens 2. This position corresponds to the outer wall surface of the protective cap 31. The protective cap 31 is pressure-fixed to the stem 1b, and the laser diode 1a is sealed.

The numerical aperture (NA) of the condensed light is 0.1
Then, while the focused spot diameter is as small as 24 μm, the core diameter of the coupled optical fiber is as large as 50 μm. Therefore, the focus position is ± 0.1 from the outer wall surface of the protective cap 31.
Even if it deviates by about mm, the change of the focused spot diameter is small, so there is almost no change in the coupling efficiency. Further, since the laser diode 1a is positioned and fixed, the error in the distance between the laser diode 1a and the Fresnel lens 2 is ± 50 μm or less. Therefore, the distance variation between the outer wall surface of the protective cap 31 and the light collecting position is 0.1 mm or less.

The semiconductor light emitting device 36 configured as described above.
In the above, the Fresnel lens 2 is adhered to the prism 30, but since it is sealed by the protective cap 31, it does not come into contact with the outside air and has heat resistance, so it does not peel off. Further, since the laser diode 1a is positioned and mounted, and the others are mechanically mounted and fixed, the coupling efficiency with the optical fiber is high,
Moreover, it can be manufactured with the focusing position being substantially fixed.
The optical semiconductor module can be easily configured by adjusting the positions of the protective cap 31 and the ferrule holder while making contact with each other and then fixing them.

Although the flat lens 2 is a Fresnel lens, it may be a gradient index lens having a flat outer shape. (Embodiment 5) FIG. 7 is a sectional view showing an optical semiconductor device of the present embodiment.

This embodiment is an improvement of the device of the fourth embodiment, and a flat lens 38 is provided at the tip of the protective cap 31. The laser diode 1a and the Fresnel lens 2 are prisms 3
It is mounted on the same side of 0. The position of the Fresnel lens 2 is adjusted so that the light output from the laser diode 1a is converted into parallel light by the Fresnel lens 2. In addition,
The lens surface 39 of the Fresnel lens 2 faces the light emission direction, but the direction is not particularly limited. Flat lens 3
8 is fixed to the protective cap 31 with low melting glass (solder glass, sealing temperature 450 ° C.).
Is crimped and fixed to the stem 1b. The parallel light incident on the flat lens 38 is diffracted by the lens surface 40a,
The light is focused on the end surface 40b. Since the light between the Fresnel lens 2 and the flat lens 38 is parallel light, the light is always collected on the end face 40b even if the distance between the two lenses changes. Since the length of the optical semiconductor device is determined by the protective cap 31, the length of the optical semiconductor device is always constant. Therefore, by fixing the receptacle 7 to the tip of the protective cap 31 of the semiconductor light emitting element 36 configured as described above, the optical semiconductor module can be easily configured.

Although the lens 2 and the lens 38 are flat lenses, the lens 2 is a lens for forming parallel light, and the lens 38 may be a gradient index lens having a flat outer shape. Moreover, although the lens 2 is mounted on the side surface of the prism 30,
The lens 2 may be mounted on the tip surface of the prism 30.

(Embodiment 6) FIG. 8 is a sectional view showing an optical semiconductor device of this embodiment. The laser diode 1a is fixedly mounted on the prism 30 provided on the stem 1b by soldering. The height of the protective cap is set to 3.5 mm, and a glass plate 33 is fixed to the tip by a low melting point glass similar to that used in Example 5 so as to close the hole 32. A plastic aspherical lens 2 having a lens thickness of 0.7 mm is provided in the cap 31 so that the lens end surface is located at a position 1.5 mm from the opening end.
Press-fit and fix. The cap 31 configured in this way
Is pressure-welded and fixed to the stem 1b, and nitrogen gas is sealed inside the protective cap 31.

The laser diode 1a includes stems 1b to 1
Since the distance is mm, the distance between the plastic lens 2 and the laser diode 1a is 0.5 mm. Therefore,
The light is collected at the height of the outer wall surface of the hole 32 of the protective cap 31.

Since the plastic lens 2 is made of an amorphous polyolefin which is a heat resistant resin, it has excellent heat resistance and moisture resistance, but is not as moisture resistant as glass. Therefore, the plastic aspherical lens 2 which is easy to mold and has good light-condensing characteristics is mounted in the glass-sealed protective cap 31 to obtain high bondability and reliability. Also, plastic lens 2
Since it is easy to lower the price of the optical semiconductor device, the cost of the optical semiconductor device can be reduced.

When the receptacle 7 is fixed to the tip of the protective cap 31 of the semiconductor light emitting element 36 thus constructed, an optical semiconductor module can be easily constructed.

[0060]

As described above, according to the first optical semiconductor device of the present invention, it is possible to provide an optical semiconductor device capable of highly reliable lens fixing even in a high humidity environment. Next, according to the second optical semiconductor device of the present invention, since the plastic lens having high heat resistance is directly molded and fixed to the holder, the number of parts can be reduced and the plastic lens can be fixed with high reliability. Made possible In addition, the hole to insert the ferrule of the receptacle is a simple single through hole,
By using the powder metallurgy method, which has high mass productivity, parts with small dimensional variation can be manufactured at low cost. In addition, the protrusions provided on the ring for positioning the ferrule are not on the same plane as the welded part of the receptacle and the ring, so welding dust generated during welding adheres to the protrusions, but does not adhere to the ferrule and the optical fiber The amount of light incident on is not reduced. Next, according to the third optical semiconductor device of the present invention,
An optical semiconductor device having a high coupling efficiency with an optical fiber can be provided.

That is, when the semiconductor element and the lens are mounted in close proximity to each other and sealed as described above, the light output from the semiconductor element is condensed by the lens at a specific position such as the tip of the protective cap, and the light is guided to the optical fiber. It is possible to provide an optical semiconductor device in which the optical coupling efficiency can be kept at a high value, the number of constituent parts can be minimized, and the axial length of the device can be kept substantially constant.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of an optical semiconductor device according to a first embodiment of the present invention.

2A and 2B are diagrams showing details of the lens of Example 1 of the present invention, in which FIG. 2A is a plan view and FIG. 2B is a sectional view.

FIG. 3 is a cross-sectional view showing a configuration of an optical semiconductor device of Example 2 of the present invention.

FIG. 4 is a sectional view showing the configuration of an optical semiconductor device according to Example 3 of the present invention.

FIG. 5 is a cross-sectional view showing the configuration of an optical semiconductor device of Example 4 of the present invention.

FIG. 6 is a diagram showing a mounted state of a lens of Example 5 of the present invention.

FIG. 7 is a sectional view showing the configuration of an optical semiconductor device according to Example 6 of the present invention.

FIG. 8 is a sectional view showing a configuration of an optical semiconductor device of Example 7 of the present invention.

FIG. 9 is a cross-sectional view of a conventional optical semiconductor device.

[Explanation of symbols]

 1 Semiconductor Light Emitting Element 1a Laser Diode 1b Stem 2 Lens 3 Holder 4 Upper Edge of Holder 5 Ring 6, 8 Hole 7 Receptacle 9 Ferrule 10 Hole 11 Optical Fiber 12 Ring Cylindrical Part 13, 14 Joint 13a Weld 16 16 Stopper 17 Welded portion 18 Metal disk 19 Protrusion 20 Tip of ring 21 Hole 22 Press-fitted ring 23 Stopper 30 Prismatic column 31 Protective cap 32 Hole 33 Glass plate 34 Submount substrate 35 Fresnel lens surface 36 Semiconductor light emitting element 37 Welded portion 38 Flat lens 39, 40a Lens Surface 40b End surface 41 Light emitting element 41a Laser diode 41b Heat dissipation stem 41c Protective cap 42 Plastic lens 43 Holder 45 Ring 45a Protrusion 47 Receptacle 49 Ferrule 410 Hole 411 Optical fiber 14 weld 415 weld 416 weld 418 disk portion 419 projecting 424 recess

Claims (19)

[Claims] 1. An optical semiconductor device for collecting light emitted from a semiconductor light emitting element by a lens and coupling it to an optical fiber, wherein the semiconductor light emitting element is built in and has a disc-shaped base. Insert a cylindrical holder provided with the center axis aligned with the light emitting element, a plastic lens provided at the tip of the holder, a cylindrical ring fitted into the holder, and a ferrule with an optical fiber fixed in the center. In an optical semiconductor device having a through hole for holding and a receptacle provided with the center axis aligned with the ring, the lens has a flange portion, and a donut-shaped metal disk is crimped to the flange portion. An optical semiconductor device, wherein the metal disk and the holder are fixed to each other by welding. 2. The optical semiconductor device according to claim 1, wherein the holder and the light emitting element are fixed to each other by welding. 3. The optical semiconductor device according to claim 1, wherein the inner diameter of the metal disc is larger than the outer diameter of the lens portion of the lens, and the outer diameter of the metal disc is larger than the outer diameter of the flange portion of the lens. 4. The optical semiconductor device according to claim 1, wherein the donut-shaped metal disk has a protrusion that is substantially vertical to the periphery of the inner diameter, and the protrusion is fitted to the flange portion of the lens. 5. The optical semiconductor device according to claim 1, wherein the flange portion of the lens is held by being sandwiched between a donut-shaped metal disk and a holder. 6. The optical semiconductor device according to claim 1, wherein the ring has a protrusion for positioning the ferrule inserted in the receptacle. 7. An optical semiconductor device for condensing light emitted from a semiconductor light emitting element with a lens and coupling it to an optical fiber, wherein the semiconductor light emitting element is built-in and has a disc-shaped base. Insert a cylindrical holder with its center axis aligned with the light emitting element, a plastic lens provided at the tip of the holder, a cylindrical ring fitted into the holder, and a ferrule with an optical fiber fixed in the center. In a photosemiconductor device having a through hole for holding and a receptacle provided with the center axis aligned with the ring, the semiconductor light emitting element has a heat dissipation stem, and the semiconductor light emitting device is provided on an inner wall of an end portion of the holder. An optical semiconductor device having an inclined surface for fixing to an element. 8. The side surface of the plastic lens has an uneven portion, the inner wall of the holder has an uneven portion, and the uneven portion of the plastic lens and the uneven portion of the holder are fitted to each other so that the plastic lens is attached to the holder. The optical semiconductor device according to claim 7, which is fixed. 9. The optical semiconductor device according to claim 7, wherein the holder, the ring, and the receptacle are made of metal, the holder and the ring are fixed to each other by welding, and the ring and the receptacle are fixed to each other by welding. 10. The optical semiconductor device according to claim 7, wherein the ring has a protrusion for positioning the ferrule inserted in the receptacle. 11. The optical semiconductor device according to claim 7, wherein the holder and the heat radiation stem of the semiconductor light emitting element are fixed to each other by welding. 12. The optical semiconductor device according to claim 1, wherein a recess is provided on the outer circumference of the ring for positioning and storing the optical semiconductor device. 13. The optical semiconductor according to claim 1, wherein the receptacle and the ring have surfaces contacting each other in a direction perpendicular to the optical axis, and the holder and the ring have surfaces contacting each other in a direction parallel to the optical axis. apparatus. 14. The optical semiconductor device according to claim 7, wherein the receptacle is a sintered body obtained by molding and baking metal powder containing iron. 15. An optical semiconductor device for collecting light emitted from a semiconductor light emitting element by a lens and coupling it to an optical fiber, wherein a disc-shaped stem having a protrusion in the center and light directed in the direction of the tip of the protrusion. A semiconductor light emitting element provided on the side surface of the projection for emitting radiation, a plastic lens provided at the tip of the projection with the optical axis aligned with the semiconductor light emitting element, and a lens having a transparent flat plate at the tip. And a semiconductor light emitting element, and a cylindrical protective cap having an end portion in contact with the stem, and a through hole for inserting a ferrule having an optical fiber fixed in the center, and the protective cap has a central axis. An optical semiconductor device, comprising: a newly provided receptacle, wherein light emitted from the semiconductor light emitting element is condensed on the tip surface of the protective cap by the lens. 16. The optical semiconductor device according to claim 15, wherein the protrusion is a prism. 17. The optical semiconductor device according to claim 15, wherein the transparent flat plate is composed of a flat plate lens, and the light emitted from the semiconductor light emitting element is condensed on the front end surface of the flat plate lens. 18. The optical semiconductor device according to claim 15, wherein the lens is adhesively fixed to the inner wall of the protective cap. 19. The optical semiconductor device according to claim 1, wherein the receptacle is a sintered body obtained by molding and baking metal powder containing iron.