JP2619199B2 - Mounting structure of optical waveguide substrate in optical switch module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure of an optical waveguide substrate in an optical switch module equipped with a waveguide type matrix optical switch.

[0002]

2. Description of the Related Art FIG. 3 is an explanatory view showing a mounting structure of an optical waveguide substrate in a conventional optical switch module. In the figure, 1 is an optical waveguide substrate on which an optical waveguide is formed, 2 is a large heat radiation fin on which the optical waveguide substrate 1 is mounted, and 3 is a heat radiation fin adjacent to the left and right sides of the optical waveguide substrate 1. 2, a connector board (PCB) mounted on the board 2 and provided with wiring for electrical connection, 4 is a connector pin provided on the board 3 with the connector, and 5 is an electric wire connecting the optical waveguide board 1 and the board 3 with the connector by wire bonding. This is a connection wire that is connected to each other. 6 is a fiber pigtail on the input side with respect to the optical waveguide substrate 1, and 7 is a fiber pigtail on the output side.
Are fixed on the radiation fins 2 by fixtures 8 and 9.

According to the above configuration, by attaching a female connector (not shown) to the connector pins 4 of the board with connector 3, an external device (not shown) and the board with connector 3 are electrically connected to each other, and It operated as an optical switch module by an electric signal.

Here, the substrate thickness of the optical waveguide substrate 1 is 1
mm, and when the optical waveguide substrate 1 and the substrate with connector 3 are connected by wire bonding, for example, bonding is first performed on the optical waveguide substrate 1 side, and then bonding is performed on the substrate with connector 3 side. Sometimes 1
st bonding portion (upper surface of optical waveguide substrate 1) and 2nd
In order to reduce the level difference from the bonding portion (the upper surface of the board 3 with connector), the board thickness of the board 3 with connector is set to 0.5.
mm. This is because, in wire bonding, the smaller the step, the easier the work can be.

However, in the optical switch module having such a structure, since the fiber pigtail is fixed to the radiating fins, the size of the radiating fins becomes large and the optical switching module becomes large. is there. Therefore, FIG. 4 is an explanatory view showing a mounting structure of a conventional optical waveguide substrate in a miniaturized optical switch module. In the figure, 10 is an optical waveguide substrate on which an optical waveguide is formed, 11 is a ceramic substrate having an optical waveguide substrate 10 mounted on its surface, 12
Denotes connector pins provided on the ceramic substrate 11, 13
Is a connection wire for electrically connecting the optical waveguide substrate 10 and the ceramic substrate 11 by wire bonding.

Numeral 14 denotes a heat radiation fin mounted on the back surface of the ceramic substrate 11, and the size of the heat radiation fin 14 is reduced to about the same size as the optical waveguide substrate 10. Reference numeral 15 denotes a fiber pigtail on the input side with respect to the optical waveguide substrate 10, and 16 denotes a fiber pigtail on the output side.

[0007]

However, in the above-described mounting structure of the optical waveguide substrate in the conventional optical switch module, since the optical waveguide substrate is mounted on the ceramic substrate, the upper surface of the optical waveguide substrate and the upper surface of the ceramic substrate are mounted. In this case, there is a problem that the step difference from the above becomes large, the connectivity at the time of wire bonding decreases, and the thickness of the optical switch module increases.

The present invention is problematic in that the step difference between the upper surface of the optical waveguide substrate and the upper surface of the ceramic substrate described above is large, thereby reducing the connectivity during wire bonding and increasing the thickness of the optical switch module. The present invention provides a mounting structure of an optical waveguide substrate in an optical switch module that can reduce a step between an upper surface of an optical waveguide substrate and an upper surface of a ceramic substrate.

[0009]

According to the present invention, there is provided an optical waveguide substrate for processing an optical signal having a bonding pad formed on an upper surface thereof, and a bonding pad formed on an upper surface for forming an electrical signal. And a mounting structure of the optical waveguide substrate in the optical switch module for electrically connecting the bonding pads on the optical waveguide substrate side and the bonding pads on the electric circuit substrate side with connection wires. In the above, the optical waveguide substrate is mounted on an upper surface of an electric circuit board , and the electric circuit board is formed by stacking a plurality of sheets.
A plurality of sheets having a layer structure and constituting the electric circuit board
Among them, the predetermined sheet on the upper surface side is the size of the optical waveguide substrate.
By overlapping the sheets that have been opened together , a step is formed at a predetermined depth at the position where the optical waveguide board is mounted on the electric circuit board to form a recess into which the optical waveguide board enters.

[0010]

According to the present invention having the above-described structure, an optical waveguide substrate is mounted on an electric circuit board, and a wire is formed between a bonding pad formed on the upper surface of the optical waveguide substrate and a bonding pad formed on the upper surface of the electric circuit substrate. They are electrically connected by bonding. Here, since the optical waveguide substrate enters the electric circuit substrate, the step between the upper surface of the optical waveguide substrate and the upper surface of the electric circuit substrate can be made smaller than the substrate thickness of the optical waveguide substrate.

[0011]

An embodiment will be described below with reference to the drawings. FIG. 1 is an explanatory view showing a mounting structure of an optical waveguide substrate according to an embodiment of the present invention, FIG. 2 is an explanatory view showing an entire structure of an optical switch module of the present embodiment, and FIG.
It is a part enlarged view. In the figure, reference numeral 19 denotes an optical waveguide substrate on which an optical waveguide is formed, and reference numeral 20 denotes a circuit on which the optical waveguide substrate 19 is mounted and a circuit for processing an electric signal or the like for driving the optical waveguide substrate 19. The formed ceramic multilayer substrate, 21 is a bonding pad formed on the optical waveguide substrate 19, 22 is a bonding pad formed on the ceramic multilayer substrate 20, and 23 is a bonding pad 21 on the optical waveguide substrate 19 side. And the bonding pad 22 on the side of the ceramic multilayer substrate 20 by wire bonding.
A connection wire for electrically connecting the connection wire and the ceramic multilayer substrate 20. One end of the connection wire 23 is connected to the bonding pad 21 on the optical waveguide substrate 19 side, and the other end is connected to the ceramic multilayer substrate 20. It is connected to the bonding pad 22 on the substrate 20 side.

Here, at the position where the optical waveguide substrate 19 of the ceramic multilayer substrate 20 is mounted, a depression 20a into which the optical waveguide substrate 19 is inserted is formed with a step at a predetermined depth. When the substrate thickness is about 1.0 mm, the depth of the depression 20a is 0.5 to 1..
It is about 0 mm. Thus, when the optical waveguide substrate 19 is mounted on the ceramic substrate 20, the upper surface of the optical waveguide substrate 19 on which the bonding pads 21 are formed and the upper surface of the ceramic multilayer substrate 20 on which the bonding pads 22 are formed. Has a step of about 0 to 0.5 mm. Then, the connection wires 23 are connected to the bonding pads 21 on the optical waveguide substrate 19 side by wire bonding and to the bonding pads 22 on the ceramic multilayer substrate 20 side, and the electrical connection between the optical waveguide substrate 19 and the ceramic multilayer substrate 20 is established. And make a connection. The ceramic multilayer substrate 20
Has a multi-layer structure in which a plurality of sheets are stacked, so that a predetermined number of sheets having an opening at the center can be stacked at the time of manufacturing, so that the depression 20a having a desired depth can be easily formed.

Reference numeral 24 denotes a connector pin provided on the ceramic multilayer substrate 20, and reference numeral 25 denotes a radiation fin mounted on the back surface of the ceramic multilayer substrate 20. The size of the radiation fin 25 is the same as that of the optical waveguide substrate 19. It is downsized to the same degree. 26 is a fiber pigtail on the input side with respect to the optical waveguide substrate 19, and 27 is a fiber pigtail on the output side.

[0014]

As described above, according to the present invention, the optical waveguide board is mounted on the upper surface of the electric circuit board, and a step is formed at a predetermined depth at the position where the optical waveguide board is mounted on the electric circuit board. In addition, since a recess into which the optical waveguide substrate enters is formed, a step between the upper surface of the optical waveguide substrate on which the bonding pads are provided and the upper surface of the electric circuit substrate can be reduced, and the work at the time of wire bonding can be performed. This has the effect of improving the performance and reducing the bending of the connection wire and reducing the breakage of the connection wire. Further, since the optical waveguide board is inserted into the electric circuit board, there is an effect that the height as the optical switch module can be suppressed. further,
The electric circuit board has a multilayer structure consisting of multiple sheets
There is a certain number of sheets with a central
It is easy to form a depression of the desired depth by overlapping
It has the effect that it can be.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a mounting structure of an optical waveguide substrate according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating the entire structure of the optical switch module of the present embodiment.

FIG. 3 is an explanatory view showing a mounting structure of an optical waveguide substrate in a conventional optical switch module.

FIG. 4 is an explanatory diagram showing a mounting structure of an optical waveguide substrate in a miniaturized conventional optical switch module.

[Explanation of symbols]

 Reference Signs List 19 optical waveguide substrate 20 ceramic multilayer substrate 20a depression 21 bonding pad 22 bonding pad 23 connection wire

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshiyuki Kawashima 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Jiro Utsunomiya 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Ryo Nagase 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Akira Himeno 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Japan Inside Telegraph and Telephone Corporation (72) Inventor Masayuki Okuno 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Kuniharu Kato 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Telephone Co., Ltd. (56) References JP-A-5-110048 (JP, A) JP-A-63-131104 (JP, A)

Claims (1)

(57) [Claims] 1. An optical waveguide substrate having a bonding pad formed on an upper surface for processing an optical signal, and an electric circuit substrate having a bonding pad formed on an upper surface for processing an electric signal. In a mounting structure of an optical waveguide board in an optical switch module for electrically connecting a bonding pad and a bonding pad on an electric circuit board side by a connection wire, the optical waveguide board is mounted on an upper surface of the electric circuit board. In addition, the electric circuit board has a multilayer structure in which a plurality of sheets are stacked.
And a plurality of sheets constituting the electric circuit board.
The predetermined number of sheets on the inner and upper surfaces are suitable for the size of the optical waveguide substrate.
An optical changeover switch characterized in that a step is formed at a predetermined depth at a position where the optical waveguide substrate is mounted on the electric circuit board by superimposing the sheets thus opened, thereby forming a recess into which the optical waveguide substrate enters. Mounting structure of optical waveguide substrate in module.