JPH0331808A - Structure of optical semiconductor module - Google Patents

Abstract

PURPOSE:To eliminate the bending of an optical fiber and to reduce the thickness size of the module by inserting the fiber through the side wall of a package in parallel with a substrate and optically coupling the optical fiber and a semiconductor chip via an optical direction changing member at the front end of the insertion. CONSTITUTION:A ferrule 57 holding the optical fiber 58 of the optical semiconductor module 1 penetrates the side wall in the package 2 fixed with the optical semiconductor module chip 52 in the inside bottom and is inserted in approximately parallel with the substrate. The optical direction changing member 8 having a mirror 7 at the front end part of the insertion is provided and the light of the optical fiber 58 is opticalally coupled to the optical semiconductor module chip 52. The optical fiber 58 is disposed in parallel with the substrate in this way and, therefore, the fiber is protected without bending. Since the height size over the entire part of the semiconductor module is reduced, the efficiency of packaging the substrate to a shelf, etc., is improved.

Description

[Detailed Description of the Invention] [Summary] Regarding the structure of an optical semiconductor module, it is possible to protect the optical fiber from bending while at the same time reducing the dimension in the thickness direction of the substrate after the optical semiconductor module is mounted on the substrate. The aim is to provide an optical semiconductor module structure that can improve the mounting efficiency of boards on shelves etc.
A ferrule holding an optical fiber is inserted through the vano gauge side wall approximately parallel to the light-receiving surface or light-emitting surface of the optical semiconductor chip, and a light direction conversion member equipped with a mirror for changing the direction of light is provided at the insertion end of the ferrule. The optical fiber and the optical semiconductor chip are attached to each other and configured to optically couple the optical fiber and the optical semiconductor chip.

[Industrial application field]

The present invention relates to an optical semiconductor module structure that optically couples an optical semiconductor chip and an optical fiber that are fixed at the bottom of a package.

[Conventional technology]

In order to miniaturize optical semiconductor modules, optical semiconductor chips and ICs such as preamplifiers are placed in the same package, and optical fibers and optical semiconductor chips are optically coupled to seal the pan cage. It has stopped.

Regarding an example of such an optical semiconductor module structure, the fifth
To explain with reference to the figure, 50 is a printed circuit board, and 51 is a package placed on this printed circuit board 50. The package 51 has a cylindrical shape with an upward opening, and an optical semiconductor chip 52 and a preamplifier rc are mounted on the inner bottom of the package 51.
53 etc. will be installed. These optical/electronic components are interconnected by bonding wires and electrically connected to predetermined electronic components on the printed circuit board Fi, 50 via terminals 54 and terminals not shown.

The upper part of the package 51 is closed with an opening 155, and a cylindrical ferrule 57 is inserted into and opposed to the light receiving surface 52a (or light emitting surface) of the optical semiconductor chip 52 through an opening 56 made at a predetermined position of the package 51. There is. This ferrule 57, which holds the optical fiber 58 in the center of its interior, supports the optical semiconductor chip 52 in the direction perpendicular to the light receiving surface 52a (Z
The outer surface of the holder 59 is guided so that the holder 59 can move in the direction of
The upper surface of 155 can be moved in a plane direction (XY plane direction) parallel to 2a.

Therefore, by moving the ferrule 57 holding the optical fiber 58 with the holder 59 in the XY plane direction relative to the optical semiconductor chip 52, the position within this plane can be adjusted.
By moving the ferrule 57 in the Z direction with respect to the holder 59, the optical axis distance of the optical fiber 58 with respect to the optical semiconductor chip 52 can be adjusted.

Note that after the positioning is completed, the ferrule 57 and the holder 59, and the holder 59 and the lid 55 are each fixed by laser welding or the like.

[Problem to be solved by the invention]

However, since such printed circuit boards 50 are generally stored in parallel to each other on a shelf or the like, as the number of board 50 accommodated increases, the height (or thickness) direction dimension of the board 50 after mounting components is reduced as much as possible. Although it is necessary to make it compact, if the ferrule 57 is arranged perpendicularly to the optical semiconductor chip 52 and therefore to the substrate 50 as in the conventional structure shown in FIG. 5, it is practically impossible to reduce the distance between the substrates. Have difficulty. Moreover, narrowing this distance is nothing but reducing the bending radius of the optical fiber 58, which is extremely undesirable because it will encourage bending and damage to the optical fiber 58.

Therefore, from the viewpoint of protecting the optical fiber 58, it is sufficient to arrange the ferrule 57 so that the optical fiber 58 can be parallel to the substrate 50, but simply replacing the package 51 vertically does not As shown in FIG. 6, a problem may arise in that the height dimension of the entire substrate 50 becomes rather large.

In view of the above points, according to the present invention, the optical fiber can be arranged parallel to the substrate, which is preferable in terms of the durability and reliability of the optical fiber, and the height direction dimension of the entire substrate after mounting the optical semiconductor module is reduced. It is an object of the present invention to provide an optical semiconductor module structure that can be kept small and is preferable in terms of mounting efficiency of a board on a shelf or the like.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, a ferrule holding an optical fiber is passed through the side wall of the package approximately parallel to the light-receiving surface or the light-emitting surface of the optical semiconductor chip in a package in which an optical semiconductor chip is fixed to the internal bottom. In addition to the insertion, the optical fiber and the optical semiconductor chip are optically coupled by attaching to the insertion end of the ferrule an optical direction changing member having a mirror for changing the direction of light. do.

[For production]

Since the ferrule holding the optical fiber is inserted through the side wall of the package substantially parallel to the light projecting surface or the light emitting surface of the optical semiconductor chip fixed to the inside bottom of the package, the size of the package in the height direction can be made compact. Moreover, since the optical fiber extends substantially parallel to the substrate, the optical fiber can be protected from bending. Further, since a light direction converting member including a mirror for changing the direction of light is attached to the insertion end of the ferrule, the optical fiber and the light emitting surface or the light receiving surface of the optical semiconductor chip are optically coupled effectively.

(Example〕 The present invention will be explained below based on illustrated embodiments.

FIG. 1 is an enlarged cross-sectional side view of an optical semiconductor module structure according to the present invention, and FIG. 2 is a cross-sectional view taken along line T in FIG. 1 in the direction of the arrow.

Referring to FIG. 1, an optical semiconductor module 1 of this embodiment
The package 2 is not particularly different in shape from the conventional package 51 (FIG. 5), and has an optical semiconductor tube 52, a preamplifier IC 53, etc. on the internal bottom, and these optical/electronic components are connected to terminals 54, etc. via printed circuit board 50
- They are common in that they are electrically connected to predetermined parts, etc.

However, the ferrule 5 holding the optical fiber 58
Instead of inserting and opposing M5 into the light receiving surface 52a of the optical semiconductor chip 52, a ferrule 57 is inserted through the side wall of the package substantially parallel to the light receiving surface 52a. A light direction conversion member 8 is provided at the insertion end of the ferrule 57 with a mirror (reflector) 7 that changes the direction of the light.
is attached to optically couple the optical fiber 58 and the optical semiconductor chip 52.

Therefore, the substrate 50 after mounting the optical semiconductor module l
The optical fiber 58 can be arranged parallel to the substrate 50 while keeping the overall height low. This improves the durability and reliability of the optical fiber 58, and improves the efficiency of accommodating boards such as shelves.

To explain the light direction conversion member 8 in more detail here, this light direction conversion member 8 has a reflective surface (mirror 7) and a cylindrical body lO into which this columnar member 9 is inserted (see Fig. 3).
a), (b)). This cylindrical member 9 can be made of aluminum, for example, and its surface can be used as the mirror 7 for light reflection by subjecting the L distribution opening to a polishing treatment or the like.

The cylindrical member 9 on which the mirror 7 is formed is a cylindrical body 10.
fixed inside.

The light direction conversion member 8 is attached to the insertion side end of the cylindrical ferrule 57, and the optical path of the light from the optical fiber 5 is converted by approximately 90 degrees by the mirror 7, and is formed in the F section of the cylindrical body IO. The light is optically coupled to the light-receiving surface 52a of the optical semiconductor chip 52 through the opening 11 (FIGS. 1 and 3(b)).

When actually performing such optical coupling, for example, the ferrule 5
7 and the light direction conversion member 8 are fixed in advance, and the ferrule 57 is attached to the package 2 in its axial direction (X direction).
The ferrule 57 is fixed to the package 2 in advance, and the light direction conversion member 8 is moved in the axial direction (X direction) and the ferrule 57 with respect to the ferrule 57. One possible method is to move it in the direction of rotation (θ direction). In either method, the movement of the ferrule 57 or the light direction conversion member 8 in the axial direction (X direction) is nothing but a parallel movement of the mirror 7, which is a reflecting mirror, and thereby the light position in the X direction can be adjusted. In addition, the ferrule 57 or the light direction conversion member 8
Movement in the rotation direction (θ direction) swings the light in the X direction (horizontal direction in FIG. 2), thereby making it possible to adjust the leading position in the X direction.

Note that the light reflecting surface of the cylindrical member 9 is not only a flat mirror 7 as shown in FIG. 1, but also a mirror 7' having a spherical shape as shown in FIG. Can focus light.

Furthermore, in this embodiment, the optical semiconductor chip 52 has been described as a light receiving element having a light receiving surface 52a.

The idea of the present invention itself can also be applied to an optical semiconductor chip which is a light emitting element.

〔Effect of the invention〕

As described above, according to the present invention, the optical fiber can be arranged parallel to the substrate, the optical fiber can be effectively protected from bending, and the dimension of the substrate in the thickness direction can be made compact. It is possible to improve the mounting efficiency of the board on a shelf or the like.

[Brief explanation of drawings]

Fig. 1 is an enlarged cross-sectional side view of the optical semiconductor module structure according to the present invention, Fig. 2 is a cross-sectional view taken along the line ■-■ in Fig. 1 in the direction of the arrow, and Fig. 3 is a perspective view of the light direction conversion member. Figure 4 is a cross-sectional side view showing another embodiment of the light direction conversion member, Figure 5 is a cross-sectional side view of a conventional optical semiconductor module structure, and Figure 6 is a vertically oriented structure of the structure shown in Figure 5. It is a cross-sectional side view showing what has been replaced. l... Optical semiconductor module, 2... Package, 7... Mirror, 8...
...Light direction conversion member, 52... Optical semiconductor chip,
57... Ferrule, 58... Optical fiber. 20th 2...Bar/ν cage 5...Lid 8...Light direction conversion member 9...Cylindrical member 10...Cylindrical body 52...Optical semiconductor chip (a) (b) Light Direction r! Il! Perspective view of the member Fig. 3 Cross-sectional side view of another light direction f conversion member Fig. 4 Conventional structure Fig. 5 56...Aperture 59...Holder

Claims (1)

[Claims] 1. A ferrule (57) holding an optical fiber (58) is placed approximately parallel to the light-receiving surface or light-emitting surface of the optical semiconductor chip (52) in a package (2) with an optical semiconductor chip (52) fixed to the internal bottom. a light direction changing member (8) which is inserted through the side wall of the package and is provided with a mirror (7) at the insertion end of the ferrule (57) to change the direction of the light;
Attach the optical fiber (58) and the optical semiconductor chip (52).
) is optically coupled to an optical semiconductor module structure.