JPH11295561A - Optical semiconductor device and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the position of an aspherical lens by easy work in a short time without using a special equipment and to optically couple a semiconductor element and an optical fiber with high efficiency. SOLUTION: In this optical semiconductor device provided with a laser diode 1, a photodiode 2, a silicon substrate 4 for loading the semiconductor elements 1 and 2, the optical fiber optically coupled with the semiconductor elements 1 and 2 for internally transmitting laser beams and the aspherical lens 3 loaded on the silicon substrate 4 for optically coupling the semiconductor elements 1 and 2 and the optical fiber, the silicon substrate 4 is provided with a V groove 5 whose axis is in almost the same direction as the optical axis direction of the laser beam between the semiconductor elements 1 and 2 and the optical fiber and the aspherical lens 3 is directly fixed to the V groove 5 so as to bring the outer peripheral surface 15 into surface contact at least on two surfaces or line contact at least at two parts with the V groove 5.

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 which is used, for example, as a light source for optical communication and optically couples a semiconductor element and an optical fiber via a lens, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a known technique relating to the structure of this type of optical semiconductor device, for example, Japanese Patent Application Laid-Open Nos. 5-37024, 4-261076, and 9-90
174 and JP-A-6-289256.

The optical semiconductor device described in Japanese Patent Application Laid-Open No. 5-37024 performs optical coupling between a semiconductor light emitting element and an optical fiber via a spherical lens. That is, a trapezoidal groove provided with an alignment pattern for fixing a semiconductor light emitting element, a cross-shaped V groove for fixing a spherical lens, and a V groove for fixing an optical fiber are formed from two semiconductor wafers. Are formed on the respective optical coupling substrates. The depths of the trapezoidal groove and the V-groove are determined by the size and shape of each optical device so that the laser emitting portion of the semiconductor light emitting device, the central portion of the spherical lens, and the central portion of the core of the optical fiber coincide. It is set according to. Note that the position adjustment of the spherical lens is performed by tilting (displacement from the lens optical axis in a horizontal cross section, hereinafter the same in this specification) and falling (displacement from the lens optical axis in a vertical cross section, hereinafter, in this specification) ) Can be ignored and has no effect on the optical coupling efficiency. Therefore, it is sufficient to adjust the distance and height to the semiconductor light emitting element. It should be noted that Japanese Patent Application Laid-Open No. 4-261076 also discloses an optical semiconductor device having substantially the same configuration.

In the optical semiconductor device described in Japanese Patent Application Laid-Open No. 9-90174, optical coupling between a semiconductor laser and an optical fiber is performed by a two-lens system having first and second lenses. The first lens is an aspherical lens that converts the laser light emitted from the semiconductor laser into parallel light, and the second lens is an upper and lower lens that collects the laser light converted into parallel light by the first lens and makes the laser light incident on an optical fiber. It is a spherical lens whose part has been cut out. Among them, the first lens is held by a lens holder welded and fixed to a base made of a metal material on which a semiconductor laser is installed. The first lens, which is an aspheric lens, is different from the above-described spherical lens in that the optical axis with the semiconductor laser must be minimized unless the lens is tilted or tilted in addition to the distance and height to the semiconductor laser. As a result, high coupling efficiency cannot be obtained. Therefore, the distance and height between the semiconductor laser and the first lens, and the inclination and tilt of the first lens are adjusted so that the laser light passing through the first lens becomes parallel light while the semiconductor laser is driven. After adjustment, fix it to the base by welding. It should be noted that JP-A-6-2
No. 89256 discloses an optical semiconductor device having a substantially similar configuration.

[0005]

However, the above prior art has the following problems.

That is, the optical semiconductor device described in Japanese Patent Application Laid-Open Nos. 5-37024 and 4-261076 is an optical coupling system using a spherical lens having large aberration. become worse. As a result, the coupling efficiency between the semiconductor light emitting element and the optical fiber decreases, and the level of output light from the optical fiber decreases. Therefore, in order to improve the level of the fiber output light, a method such as increasing the laser output emitted from the semiconductor light emitting element or increasing the assembly precision to minimize the coupling loss between the semiconductor light emitting element and the optical fiber is used. I have to take it. However,
In the former case, the drive current of the semiconductor light emitting element must be increased, which causes disadvantages such as an increase in power consumption and heat generation and a reduction in the life of the semiconductor light emitting element. In the latter case, it is difficult to reduce the cost of parts and assembly.

Further, the optical semiconductor device described in JP-A-9-90174 and JP-A-6-289256 is
This is an optical coupling system using an aspheric lens having less aberration than a spherical lens as a first lens of the two lenses. Therefore, unlike the above known example, the laser light condensing property is improved, so that the coupling efficiency between the semiconductor laser and the optical fiber can be increased. However, at the time of assembling the first lens, which is an aspherical lens, the first lens is fixed by welding after the semiconductor laser is driven and the position of the aspherical lens is adjusted as described above. Special equipment for adjusting the lens so as to be parallel light while monitoring the laser light passing through it is required separately. At this time, a great deal of time is required to adjust the distance and height between the semiconductor laser and the lens, and the inclination and tilt of the lens. Further, since the first lens is held by a lens holder made of a metal material which is welded and fixed to a base on which a semiconductor laser is installed, an assembling operation is complicated. Further, there is also a disadvantage that the cost of parts is increased by the amount of the lens holder and the size of the apparatus is further increased. An object of the present invention is to provide an optical semiconductor device capable of adjusting the position of an aspheric lens in a short and easy operation without using special equipment and capable of optically coupling a semiconductor element and an optical fiber with high efficiency. It is to provide a manufacturing method thereof.

[0008]

(1) In order to achieve the above object, the present invention provides a semiconductor device comprising at least one of a semiconductor light emitting device and a semiconductor light receiving device, and a substrate member on which the semiconductor device is mounted. An optical fiber optically coupled to the semiconductor element and internally transmitting laser light, and an optical semiconductor device having a lens mounted on the substrate member and optically coupling the semiconductor element and the optical fiber, The substrate member includes a groove having an axis substantially in the same direction as the optical axis direction of the laser light between the semiconductor element and the optical fiber, and the lens has an outer peripheral surface having at least two surfaces in the groove. It is directly fixed to the groove so as to make surface contact or line contact at at least two places. Since the lens is directly fixed to the groove formed in the substrate member, the groove is accurately formed at a predetermined depth by, for example, anisotropic etching, so that the height of the semiconductor element and the lens can be adjusted without any adjustment. be able to. Also, the axis of the groove is set in a direction substantially parallel to the optical axis direction of the laser beam, and the outer peripheral surface of the lens is brought into surface contact with at least two surfaces or in line contact with at least two places. As a result, the surface bisecting the angle formed by the two surfaces (or the extended surface) of the surface contact and the bisector of the angle formed by the two lines (or the extended line) of the line contact are formed by the axis of the groove. By setting in advance so as to be parallel to the direction, it is possible to make the inclination of the lens zero by simply installing the lens in the groove. Furthermore, the lens is installed in the groove by appropriately setting the angle as viewed in the vertical cross section of the two surfaces of the surface contact and the two lines of the line contact, such as making two lines parallel to the optical axis direction of the laser light. By simply doing so, the tilt of the lens can be reduced to zero. As described above, in adjusting the position of the lens, only the distance between the lens and the semiconductor element needs to be adjusted. Therefore, it is sufficient to adjust the position while monitoring the distance with a simple monitor. Therefore, even when using an aspherical lens to improve the efficiency of optical coupling between the semiconductor element and the optical fiber, without using special equipment while driving the semiconductor element as in the conventional structure,
The position of the lens can be adjusted in a short and easy operation.

(2) In the above (1), preferably,
The cross section of the groove is any one of a substantially V shape, a substantially trapezoidal shape, and a substantially rectangular shape.

(3) In the above (2), more preferably, the groove is formed by anisotropic etching.

(4) In the above (1), preferably, the lens has a cylindrical portion, and the cylindrical portion comes into surface contact with the groove portion or linearly contacts at least two places. Is directly fixed to the groove.

(5) In the above (4), more preferably, when the length of the cylindrical portion in the lens central axis direction is t and the outer diameter of the lens is D, the lens is (1/1).
5) It is configured such that ≦ (t / D) <1.
By setting (t / D) ≧ (1/15), the length of the cylindrical portion with respect to the lens outer diameter can be made sufficiently large, and the lens can be reliably prevented from falling. Also, (t / D)
By setting it to <1, it is possible to prevent the aberration from increasing as in the case of a spherical lens, to secure the laser light focusing property, and to surely increase the coupling efficiency.

(6) In the above (5), more preferably, when the distance from the semiconductor element to the cylindrical portion is L and the focal length of the lens is f, 0.7 ×
They are arranged so that (1/2) × D ≦ L ≦ f.
By setting 0.7 × (1/2) × D ≦ L, it is possible to reliably prevent the distance from the semiconductor element to the cylindrical portion from becoming too small and causing the cylindrical portion to interfere with the end of the groove. .
Also, for example, when a semiconductor element and an optical fiber are coupled by using two lenses, the anti-semiconductor element side of the lens on the semiconductor element side must emit and emit laser light in at least a parallel direction. By doing so, it is possible to reliably prevent the distance from the semiconductor element to the cylindrical portion from becoming excessively large and causing the laser beam to spread more than the parallel direction.

(7) In the above (4), preferably, the lens has two curvature portions located on both sides of the cylindrical portion and serving as a laser incident side end or an emission side end. When the thickness of the lens from the front end of one curvature portion to the rear end of the other curvature portion is T, T <D. At the time of assembly, even if an attempt is made to bring the cylindrical portion close to the semiconductor element in order to reduce the occurrence of optical coupling loss and improve the optical coupling efficiency, there is a case where the cylindrical portion interferes with the end of the groove of the substrate member and cannot be approached more than a certain degree However, by providing the laser incident side end with a curvature portion, even in such a case, the curvature portion can be closer to the semiconductor element side than the cylindrical portion without interference. Therefore, the occurrence of optical coupling loss during assembly can be minimized.

(8) In order to achieve the above object, the present invention provides a semiconductor device comprising at least one of a semiconductor light emitting device and a semiconductor light receiving device, an electronic component device for driving and controlling the semiconductor device, and the semiconductor device. An element and a substrate member on which the electronic component element is mounted, and an optical fiber that is optically coupled to the semiconductor element and internally transmits laser light;
A lens mounted on the substrate member for optically coupling the semiconductor element and the optical fiber, metallized wiring and lead terminals for electrically connecting the semiconductor element to the outside of the device, and housing the substrate member And a ferrule attached to a pipe end provided at one end of the case, the substrate member having an axis line between the semiconductor element and the optical fiber. The lens is provided with a groove that is substantially the same direction as the optical axis direction of the laser light, and the lens is configured such that an outer peripheral surface thereof comes into surface contact with the groove at least two surfaces or at least two lines. It is directly fixed in the groove.

(9) In order to achieve the above-mentioned object, in the above-mentioned method (1) or (8), the lens is adsorbed by an adsorbing member, conveyed, and placed in a groove of the substrate member. After adjusting the position of the lens on the groove so that the distance from the semiconductor element becomes a predetermined value while the suction member is in the suction state, the lens is held at the adjusted position by an elastic holding member. Then, after fixing the lens in the groove portion in the holding state, the suction member and the holding member are removed from the lens. By holding and fixing the lens in the groove with an elastic holding member, no extra external force is applied to the contact portion between the lens outer peripheral surface and the groove,
The lens can be mounted so that the outer peripheral surface of the lens naturally follows the groove. Accordingly, the lens can be stably positioned and fixed, so that the lens can be more reliably prevented from tilting or falling, and high optical coupling efficiency can be secured. This is particularly effective when the lens has a small diameter and a small thickness.

(10) In the above (9), as the holding member, at least one of a wire member, a tape member, a spring member, a shock absorbing member, and a constituent member provided with these members is used.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. In each of the drawings, some of the metallized wiring, wire bonding, adhesive, laser welding, and the like are omitted as appropriate to avoid complication. A first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a horizontal sectional view illustrating the entire structure of the optical semiconductor device according to the present embodiment.

In FIG. 2, the optical semiconductor device includes a laser diode 1 as a semiconductor light emitting element and a photodiode 2 as a semiconductor light receiving element, and electronic component elements (not shown) for driving and controlling the laser diode 1 and the photodiode 2. ), A silicon substrate 4 on which the laser diode 1, the photodiode 2, and the electronic component element are mounted, and an optical fiber optically coupled to the laser diode 1 and the photodiode 2 and internally transmitting laser light (not shown, described later). An aspherical lens 3 mounted on a silicon substrate 4 and optically coupling the laser diode 1 and the photodiode 2 to the optical fiber, and the laser diode 1 and the photodiode 2 outside the device. Metallized wiring 12 for electrical connection
And a lead terminal 7, a case 6 for accommodating the silicon substrate 4, and a ferrule 9 having an optical fiber therein and attached to an end of a pipe 8 provided at one end of the case 6. The optical coupling between the photodiode 2 and the optical fiber is performed by the aspherical lens 3 alone.

The case 6 is made of, for example, a ceramic material having a box shape and has lead terminals 7 on both sides.
A total of eight are provided. A cap (not shown) for shielding the inside of the case 6 from the outside is joined to the upper surface of the case 6. The dimensions of the box-shaped case 6 are, for example, 4.6 m in height (perpendicular to the paper surface in FIG. 2).
m, the width (vertical direction in FIG. 2) is 7.4 mm, and the length (FIG.
(Middle and lateral direction) is 10.0 mm, and the lead terminals 7
Are provided at intervals of, for example, 2.54 mm.

The pipe 8 is a metal member and is fixed to the case 6 in advance by silver brazing (not shown) before the ferrule 9 is attached (described later).

The ferrule 9 is composed of a zirconia member 10 in which an optical fiber strand is provided and fixed, and a metal member 11 in which the coating of the optical fiber is fixed.
When the ferrule 9 is attached, the laser beam passed from the aspherical lens 3 is incident on the optical fiber, and the position is adjusted so that the optical fiber output at that time is maximized. It is fixed to the end face by laser welding (not shown). The tip 14 of the optical fiber exposed at the tip of the zirconia member 10 is oblique as shown in FIG. 2 to prevent the laser light oscillated from the laser diode 1 from returning to the laser diode 1 as reflected return light at the optical fiber tip 14. Has been processed. At this time, the laser diode 1 and the aspherical lens 3 are used to efficiently enter the laser beam into the obliquely processed optical fiber.
The laser beam is emitted obliquely with the optical axis shifted relatively by several tens of μm, and the silicon substrate 4 on which the laser diode 1 and the aspherical lens 3 are mounted is slightly shifted downward from the center of the case 6 in FIG. The laser light transmitted from the aspherical lens 3 is emitted upward in FIG. 2 by installation.

FIG. 1 is a perspective view showing a lens mounting structure which is one of the features of the optical semiconductor device of the present embodiment, and FIGS. 3A and 3B are a longitudinal sectional view and a side view thereof. Show. In FIGS. 1, 3 (a) and 3 (b), the laser diode 1 and the photodiode 2 are markers (not shown) on the metallized wiring 12 formed on the upper surface of the silicon substrate 4. ) Are positioned at predetermined positions with the marks as marks. The laser diode 1 and the photodiode 2 are electrically connected to the metallized wiring 12 on the upper surface of the silicon substrate 4 via a wire bonding 13.

In the silicon substrate 4, a V-shaped groove 5 having a substantially V-shaped cross section with a bottom is formed by anisotropic etching, and the V-shaped groove 5 is formed by slopes 5a and 5b on both sides and a bottom surface 5a.
c (see FIG. 3B). Also, V
The groove 5 has an axis that is substantially parallel to the optical axis direction of the laser light between the laser diode 1 and the photodiode 2 and the optical fiber. Further, the V-groove 5 is formed as shown in FIG.
As shown in (b), the side shape and the cross-sectional shape are inverted trapezoidal shapes, and at this time, the vertical height of the bottom surface 5c is constant in the axial direction (that is, the bottom surface 5c is a horizontal plane).
It has become. The silicon substrate 4 has, for example, a thickness of 1.0 mm (vertical direction in FIG. 3A) and a depth of the V groove 5 of 0.78 mm.

The aspherical lens 3 has a substantially columnar shape with a curvature on an incident end face and an exit end face with respect to laser light emitted from the laser diode 1, and is formed mainly by glass molding or press molding. I have. Specifically, the aspherical lens 3 has a cylindrical portion 3a having a substantially cylindrical shape.
And two curvature portions 3b and 3c located on both sides of the cylindrical portion 3a and serving as a laser incident side end or an emission side end. The outer peripheral surface 15 of the cylindrical portion 3a is The two slopes 5a and 5b are in line contact with each other at two places (FIG. 3).
As shown in the line contact portion 16 in (b), it is directly bonded and fixed with an adhesive (not shown) (detailed later). Also,
The dimensions of the lens 3 and its surroundings are as follows:
a of the lens 3 in the central axis direction (see FIG. 3A), the outer diameter D of the lens 3 (the same), and the lens thickness T from the front end of one curvature portion 3b to the rear end of the other curvature portion 3c. And the distance L from the laser diode 1 to the cylindrical portion 3b is (1/15) ≦ (t / D) <10.7 × (D / 2) ≦ L ≦ 1.0 × (D / 2) It is configured and arranged so that T <D. Specifically, for example, D = 1.5 mm, t = 0.2 to 0.3 mm, T =
0.8 mm and L = 0.53 mm. The numerical aperture of the aspheric lens 3 is 0.55, and the focal length f = 0.7.
It is 8 mm.

Next, another method of fixing the lens to the V groove 5 of the silicon substrate 4, which is another feature of the present embodiment, is shown in FIG.
This will be described with reference to FIG.

When the lens 3 is fixed, first, the aspherical lens 3 is vacuum-adsorbed and conveyed by the lens holding pipe 21 and mounted on the V groove 5 of the silicon substrate 4 on which the laser diode 1 and the photodiode 2 are mounted. Place. Next, lens 3
While holding the lens, the lens holding pipe 21 is
And the position of the aspherical lens 3 in the V-groove 5 is adjusted so that the distance between the laser diode 1 and the photodiode 2 on the silicon substrate 4 becomes a predetermined value.

When the distance is adjusted to a predetermined value by the adjustment, the wire member 2 attached to the wire holder 19 in this state.
0 is brought into contact with the outer peripheral surface 15 of the aspherical lens 3 and the wire holder 19 is further moved in the direction of the arrow in FIG. The lens 3 is pressed into the V-shaped groove 5 and the aspherical lens 3
In its adjusted position. When the aspherical lens 3 is pressed by the wire member 20, it can be said that there is no possibility that the aspherical lens 3 may be slightly displaced. The present inventors have confirmed that the temperature is twice or less. It has been found that with such a positional deviation amount and an angular deviation amount, the optical coupling efficiency between the laser diode 1 and the optical fiber does not greatly decrease, and there is no problem.

Thereafter, while the aspherical lens 3 is held at a predetermined position in the V-groove 5, an adhesive (not shown) is applied to the portion where the aspherical lens 3 and the V-groove 5 are in contact (ie, FIG. )
(Corresponding to the line contact portion 16) and cured, and the aspheric lens 3 is fixed to the V groove 5. Note that as the adhesive at this time, an ultraviolet curable adhesive that can be cured in a short time while holding the aspherical lens 3 is preferable.

After fixing the aspherical lens 3 in this way, the lens holding pipe 21 and the wire member 20 are removed from the aspherical lens 3 respectively.

The operation and effect of this embodiment configured as described above will be sequentially described below.

(1) Function and Effect of Lens Mounting Structure Since the aspherical lens 3 is directly fixed to the V-groove 5 formed in the silicon substrate 4 by anisotropic etching, the V-groove 5 is previously formed at a predetermined depth. The laser emitting portion of the laser diode 1 and the photodiode 2 can be formed with high precision.
The height adjustment of the optical axis of the laser incidence part and the optical axis of the aspherical lens 3 can be performed without adjustment. The axis of the V-groove 5 is in a direction substantially parallel to the optical axis direction of the laser beam, and the outer peripheral surface 15 of the cylindrical portion 3a of the aspherical lens 3 is Is in line contact with
Simply placing the aspheric lens 3 in the V-groove 5 makes the inclination of the aspheric lens 3 zero (that is, the center axis direction of the aspheric lens 3 matches the optical axis direction of the laser beam). Furthermore, V
The groove 5 has an inverted isosceles trapezoidal side shape and a transverse cross-sectional shape, and the vertical height of the bottom surface 5c is constant in the axial direction. , The inclination of the aspherical lens 3 becomes zero. As a result, as described above with reference to FIG. 4, in adjusting the position of the aspherical lens 3, the position between the front surface of the aspherical lens 3 and the laser emission part of the laser diode 1 or the laser incidence part of the photodiode 2 is increased. Since it is only necessary to adjust the distance, it is sufficient to adjust the distance while measuring the distance with a simple monitor device, for example. Therefore, the position of the aspherical lens 3 can be adjusted in a short time and with a simple operation without using special equipment while driving the semiconductor element as in the conventional structure. Further, since the aspherical lens 3 is directly fixed to the V-groove 5 without using a lens holder as in the conventional structure, cost reduction can be achieved by reducing the number of parts and the number of working steps, and the size of the apparatus can be reduced. Therefore, there is also an effect that double-sided mounting on a printed circuit board can be easily realized.

(2) Function and Effect of Lens Fixing Method When the aspherical lens 3 is fixed to the V groove 5 of the silicon substrate 4, the aspherical lens 3 is fixed by the elastic wire member 20.
By holding and fixing in the groove 5, the lens outer peripheral surface 15
The lens outer peripheral surface 15 can be mounted so as to naturally follow the V-groove 5 without an extra external force being applied to a contact portion (line contact portion 16) between the V-groove 5 and the contact portion. Therefore, the aspherical lens 3 can be stably positioned and fixed, so that in addition to the effect of the above (1), the inclination and tilting of the aspherical lens 3 can be more reliably prevented, and high optical coupling efficiency can be secured. . This is particularly effective when the aspheric lens 3 has a small diameter and a small thickness.

(3) Effect of Setting t / D If t / D is too small, the length of the cylindrical portion with respect to the outer diameter of the lens is not sufficient, and it is difficult to prevent the lens from falling down. (See FIG. 3A). The inventors of the present invention have studied variously changing the value of t / D. As a result, the lower limit value of t / D that can reliably prevent the lens from falling is t / D.
= 1/15 was determined to be appropriate. On the other hand, t / D = 1
In this case, the lens becomes substantially close to a spherical lens, so that the aberration increases, the laser light condensing property decreases, and it becomes difficult to improve the coupling efficiency. In the present embodiment, as described above, the length t of the cylindrical portion 3a in the lens central axis direction and the outer diameter D of the aspherical lens 3 are (1/15) ≦ (t / D) <1. . This makes it possible to more reliably prevent the aspherical lens 3 from falling down, and to maintain a high coupling efficiency.

(4) Function and Effect of Setting L If L is too small, the distance from the laser diode 1 to the cylindrical portion 3a becomes too small, and the cylindrical portion 3a may interfere with the end of the V groove 5. (See FIG. 3A). The inventors of the present invention have studied variously the values of L and D in consideration of the end slope shape of the V-groove 5 by anisotropic etching, and as a result, the lower limit value of L that can reliably prevent the interference is 0. 0.7 × (D / 2) was determined to be appropriate. On the other hand, the laser light emitted from the laser diode 1 usually has a divergence angle of about 30 degrees, but if L becomes too large, the spread laser light may not sufficiently enter the aspheric lens 3. The inventors of the present application have studied variously changing the values of L and D. As a result, the upper limit of L at which laser light can sufficiently enter the aspherical lens 3 is 1.0 × (D / D / D).
2) was determined to be appropriate. As a typical example for realizing the range of L, the numerical aperture of the aspherical lens 3 is set to 0.5 to 0.6, and the focal length of the aspherical lens 3 is set to 0.7 to 0. It may be 9 mm. In this embodiment, as described above, the numerical aperture of the aspherical lens 3 is 0.55, the focal length is 0.78 mm, and the distance L from the laser diode 1 to the cylindrical portion 3a is 0.7 × (D /
2) It is set so as to satisfy ≦ L ≦ 1.0 × (D / 2). Accordingly, it is possible to reliably prevent the cylindrical portion 3a from interfering with the end of the V-groove 5, and to reliably and efficiently make the laser light from the laser diode 1 incident on the aspherical lens 3.

(5) Others When assembling the aspherical lens 3, even if the cylindrical portion 3a is brought closer to the laser diode 1 in order to reduce the occurrence of optical coupling loss and improve the optical coupling efficiency, the V
In some cases, the end of the groove 5 cannot be approached more than a certain degree due to interference with the end. Also in this case, the curvature portion 3b can be made closer to the laser diode 1 side than the cylindrical portion 3a without interference. Therefore, the occurrence of optical coupling loss during assembly can be minimized.

In the first embodiment, an optical semiconductor device having both a laser diode 1 and a photodiode 2 has been described as an example of a semiconductor element. However, the present invention is not limited to this. It can be applied to an optical semiconductor device having only the same, and the same effect is obtained.

In the first embodiment, the adjustment of the distance direction between the aspherical lens 3 and the laser diode 1 is performed while measuring the distance with a monitor device. However, the present invention is not limited to this. A mark (not shown) for aligning the aspherical lens 3 may be provided on the substrate 4, and a predetermined distance may be set by mounting the aspherical lens on the mark. In this case, a similar effect is obtained.

Further, in the first embodiment, the V-groove 5 is formed in the silicon substrate 4 for fixing the aspheric lens 3, but the present invention is not limited to this. It may be a trapezoidal shape (those other than an equal leg trapezoidal shape) or a substantially rectangular groove. In these cases, a similar effect is obtained.

In the first embodiment, the adhesive is applied to the line contact portion 16 in a state where the aspherical lens 3 is set in the V-groove 5 and pressed against the V-groove 5. However, the present invention is not limited to this. An adhesive may be applied in advance to the portion where the aspherical lens 3 is installed. In this case, a similar effect is obtained.

Further, in the first embodiment,
A wire member 20 is used as a member for pressing the aspherical lens 3.
, But is not limited to this. That is, a member having elasticity so that an extra external force is not applied when the outer peripheral surface 15 of the aspherical lens 3 comes into line contact with the surface of the V groove 5 is sufficient, and a tape member, a spring member, a shock absorbing member, and Other constituent members provided with these members may be used. At this time, for example, the tip shape may be a pin shape, a flat shape, a V-shaped shape, or the like. In these cases, a similar effect is obtained.

In the first embodiment, the size of the box-shaped case 6 is 4.6 mm in height and 7.4 m in width.
m and a length of 10.0 mm, but are not limited thereto. That is, in order to enable double-sided mounting on a printed circuit board, the height of the case 6 is at least 4.7.
mm or less is sufficient. In order to make the height of the case 6 not more than 4.7 mm, it is sufficient that the outer diameter D of the aspherical lens 3 attached in the case 6 is not more than 2.0 mm, and D = 1 as in the present embodiment. It is not limited to 0.5 mm.

Further, in the first embodiment,
As shown in FIG. 3B, the lens outer peripheral surface 15 and the V-groove 5 are in line contact with each other at the two line contact portions 16, 16, but are not limited to this, and are in line contact at three or more places. Is also good. For example, it is conceivable that the height of the bottom surface 5c is further raised, and the bottom surface 5c is also in line contact with the lowermost portion of the lens outer peripheral surface 15. In these cases, a similar effect is obtained. Further, the present invention is not limited to the line contact, and may be in surface contact with the V groove 5 on two surfaces. A modification in this case will be described with reference to FIG. FIG.
FIG. 6 is a side view illustrating a lens mounting structure in this modification, and is a view substantially corresponding to FIG. 3B of the first embodiment. As shown in FIG. 5, in this modification, the cylindrical portion 3a of the aspherical lens 3 has a substantially polygonal cylindrical shape (accurately, a substantially dodecagonal cylindrical shape). The two surfaces 15a and 15b form a surface contact portion 22 between the two slopes 5a and 5b of the V-shaped groove 5. That is, a substantially polygonal cylindrical shape of the cylindrical portion 3a is formed in advance in accordance with the angle (for example, 54.7 °) of the slopes 5a and 5b of the V-groove 5 formed by anisotropic etching. Face 1
Surface contact at 5a and 15b is enabled. As in the first embodiment, the aspherical lens 3 having the substantially polygonal cylindrical portion 3a can be easily formed mainly by glass molding or press molding without the need for post-processing. In addition, the polygonal shape of the outer peripheral surface 15 of the cylindrical portion 3a is not limited to a regular polygon. Further, the cylindrical portion 3a is not limited to a substantially polygonal cylindrical shape, and may be a cylindrical shape in which a curved surface and a flat surface are mixed on the outer peripheral surface 15. In this modification,
Because of the surface contact, there is an effect that the aspherical lens 3 can be mounted in the V groove 5 in a more stable state than in the first embodiment.

It is needless to say that the surface contact is not limited to two surfaces but may be three or more surfaces.

A second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a horizontal sectional view illustrating the entire structure of the optical semiconductor device according to the present embodiment.

In FIG. 6, the optical semiconductor device according to the present embodiment is different from the optical semiconductor device according to the first embodiment in that an optical isolator 17 for preventing reflection and a glass plate for hermetically sealing the inside of the case 6 are provided. 18 are additionally fixed.

The optical isolator 17 has an outer diameter of 2.0, for example.
mm and a length of 2.6 mm, and is incorporated in advance as a part of the ferrule 9 with an optical isolator so as to be located at the optical fiber tip 14 of the zirconia member 10. At this time, the optical isolator 17 is fixed to the optical fiber tip 14 by bonding with an adhesive (not shown) having a high laser beam transmittance so that no space remains. As the adhesive, an ultraviolet-curable adhesive or a thermosetting adhesive is preferable, and a thermosetting adhesive is also preferable as the ultraviolet-curable adhesive. Further, with such a structure, the optical isolator 17 can perform position adjustment together with the ferrule 9 without using a holder member for holding and fixing the optical isolator 17 alone. That is, the ferrule 9 with the optical isolator 17 is installed on the end face of the pipe 8, the laser light that has passed through the aspherical lens 3 is incident on the optical fiber, and the position of the ferrule 9 is adjusted so that the optical fiber output is maximized. Metal member 11 of ferrule 9
Is fixed to the end face of the pipe 8 by laser welding (not shown).
As described above, the adjustment can be performed in substantially the same manner as the optical fiber position adjustment method described in the first embodiment.

The glass plate 18 is provided on the side wall of the case 6 between the aspherical lens 3 and the optical isolator 17. The glass plate 18 is joined to the side wall of the case 6 with low melting point glass or Au80-Sn20 eutectic solder (not shown).
At this time, in order to prevent the laser light passing through the aspherical lens 3 from returning to the laser diode 1 as reflected return light, the laser light is obliquely attached as shown in the figure. The glass plate 18 is made of, for example, sapphire, and an antireflection film is formed on the laser light incident surface and the laser light incident surface at a multilayer film.

The other structure is almost the same as that of the first embodiment.

According to the present embodiment, the following effects are obtained in addition to the effects similar to those of the first embodiment. That is, by installing the optical isolator 17 between the aspherical lens 3 and the optical fiber, almost all the return light returning to the laser diode 1 due to the reflection at the optical fiber tip 14 and the reflection from the system side is removed and reduced. can do. Therefore, the laser diode 1 can be operated more stably and at a higher speed than the optical semiconductor device of the first embodiment, and an optical semiconductor device with an increased transmission capacity can be realized. Further, by attaching the glass plate 18 to the side wall of the case 6 and attaching a cap (not shown) to the upper surface of the case 6, the inside of the case 6 can be completely airtightly sealed. 1 can prevent unstable operation and shorten the life, and can improve reliability.

In the first and second embodiments, the optical semiconductor device in which the optical fiber of the laser diode 1 and the photodiode 2 and the optical fiber are coupled by one single aspherical lens 3 has been described as an example. Not limited to this. That is, as long as the coupling optical system uses at least one aspheric lens, the same structure and method as those of the first and second embodiments can be applied to the mounting structure and mounting method of the aspheric lens 3 among them. Therefore, a similar effect can be obtained in these cases. When the coupling optical system is formed using a plurality of lenses including at least one aspherical lens 3 in this manner, the upper limit of the setting of L described in (4) in the first embodiment is more It may be large. That is, for example, when the laser diode 1 and the optical fiber are coupled using two lenses, and the aspheric lens 3 is used as the lens on the laser diode 1 side, the rear surface side of the aspheric lens 3 (the anti-photodiode) It is sufficient for the first side) to emit a laser beam in at least a parallel direction. In this case, if the value of L is set to be equal to or less than the focal length f, it is possible to reliably prevent the laser light from spreading in the parallel direction, so it is sufficient if the upper limit value of L is set to f. That is, the setting of L in this case is 0.7 × (D
/ 2) ≦ L ≦ f.

[0052]

According to the present invention, the position of the aspherical lens can be adjusted in a short and easy operation without using any special equipment, and the semiconductor element and the optical fiber can be optically coupled with high efficiency. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a lens mounting structure as a main part of an optical semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a horizontal cross-sectional view illustrating the entire structure of the optical semiconductor device illustrated in FIG.

3 is a longitudinal sectional view and a side view of the structure shown in FIG.

FIG. 4 is a diagram illustrating a method of fixing a lens to a V groove of a silicon substrate.

FIG. 5 is a side view illustrating a lens mounting structure according to a modification of the first embodiment.

FIG. 6 is a horizontal sectional view illustrating an entire structure of an optical semiconductor device according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 laser diode (semiconductor light emitting element) 2 photodiode (semiconductor light receiving element) 3 aspheric lens (lens) 4 silicon substrate (substrate member) 5 V groove (groove) 6 case 7 lead terminal 8 pipe 9 ferrule 12 metallized wiring 13 wire Bonding 15 Lens outer peripheral surface 16 Line contact portion 19 Wire holder 20 Wire member (holding member) 21 Lens holding pipe (adsorption member) 22 Surface contact portion

 ──────────────────────────────────────────────────の Continuing from the front page (72) Koji Yoshida, Inventor 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (72) Inventor Tadaaki Ishikawa 502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref.

Claims (10)

[Claims] 1. A semiconductor device comprising at least one of a semiconductor light emitting device and a semiconductor light receiving device, a substrate member on which the semiconductor device is mounted, and an optical fiber optically coupled to the semiconductor device for internally transmitting laser light. An optical semiconductor device having a lens mounted on the substrate member and optically coupling the semiconductor element and the optical fiber, wherein the substrate member has a laser beam whose axis is between the semiconductor element and the optical fiber. The lens has a groove that is substantially the same direction as the optical axis direction of the lens. The lens directly contacts the groove so that the outer peripheral surface makes surface contact with the groove at least two surfaces or at least two lines. An optical semiconductor device, being fixed. 2. The optical semiconductor device according to claim 1, wherein said groove has one of a substantially V-shaped cross section, a substantially trapezoidal shape, and a substantially rectangular shape. Optical semiconductor device. 3. The optical semiconductor device according to claim 2, wherein said groove is formed by anisotropic etching. 4. The optical semiconductor device according to claim 1, wherein said lens has a cylindrical portion, and said cylindrical portion is
The optical semiconductor device is directly fixed to the groove so as to make surface contact with the groove or at least two lines. 5. The optical semiconductor device according to claim 4, wherein, when the length of the cylindrical portion in the direction of the central axis of the lens is t and the outer diameter of the lens is D, (1/15) ≦ An optical semiconductor device, wherein (t / D) <1. 6. The optical semiconductor device according to claim 5, wherein when a distance from said semiconductor element to said cylindrical portion is L and a focal length of said lens is f, 0.7 × (D / 2) ≦. An optical semiconductor device, wherein the optical semiconductor device is arranged so that L ≦ f. 7. The optical semiconductor device according to claim 4, wherein the lens has two curvature portions located on both sides of the cylindrical portion and serving as a laser incident side end or an emission side end. An optical semiconductor device characterized in that T <D when a lens thickness from the front end of one curvature portion to the rear end of the other curvature portion is T. 8. A semiconductor element comprising at least one of a semiconductor light emitting element and a semiconductor light receiving element, an electronic component element for driving and controlling the semiconductor element, a substrate member on which the semiconductor element and the electronic component element are mounted, and An optical fiber that is optically coupled to the semiconductor element and internally transmits a laser beam; a lens mounted on the substrate member and optically coupling the semiconductor element and the optical fiber; Semiconductor device having a metallized wiring and lead terminals for electrical connection, a case for accommodating the substrate member, and a ferrule having the optical fiber provided therein and attached to a pipe end provided at one end of the case. In the above, the substrate member has a groove portion whose axis is substantially the same as the optical axis direction of the laser light between the semiconductor element and the optical fiber. The optical semiconductor device, wherein the lens is directly fixed to the groove so that an outer peripheral surface of the lens comes into surface contact with the groove at least at two surfaces or a line contact at at least two places. 9. The method for manufacturing an optical semiconductor device according to claim 1, wherein the lens is sucked by an attraction member, conveyed, and placed in the groove of the substrate member, and the lens is held in the attraction state of the attraction member. After adjusting the position of the lens on the groove so that the distance from the semiconductor element becomes a predetermined value, the lens is held at the adjusted position by an elastic holding member. A method for manufacturing an optical semiconductor device, comprising: after fixing a lens in the groove, removing the suction member and the holding member from the lens. 10. The method of manufacturing an optical semiconductor device according to claim 9, wherein said holding member is at least one of a wire member, a tape member, a spring member, a shock absorbing member, and a constituent member including these members. A method for manufacturing an optical semiconductor device, characterized by using: