JPH09101434A - Module for optical communication and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need to perform operation in the narrow space in a package and to facilitate operation for aligning optical axes with each other and connecting an optical signal transmission member and a photoelectric transducing element by connecting them through an optical system frame. SOLUTION: After the photoelectric converting element 1 and an element stem 2 are coupled with the horizontal part 3a of the optical system frame 3, a ferrule holding member 5 and a lens 4 are fixed to the vertical part 3 of the optical system frame 3 while the optical axes are positioned. A ferrule 6 equipped with an optical fiber is inserted and held, and while an optical signal is projected from the optical fiber, the ferrule is connected and fixed by adjusting the position so that the optical coupling with the photoelectric transducing element 1 becomes maximum. Then, an electric element is mounted on a substrate 8 where an electric circuit is constituted and covered with a sealant 10, and then the optical system frame 3 is connected onto the substrate 8 ad covered with a case 7 fir airtight sealing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package type optical communication module and a method for manufacturing the same.

[0002]

2. Description of the Related Art A package type optical communication module is used for converting an optical signal and an electric signal. The structure is such that a photoelectric conversion element such as a laser diode or a photodiode and an electric element (IC chip) for driving the photoelectric conversion element are built in a box-shaped package, and as a light signal transmission member for the photoelectric conversion element. In some cases, a ferrule equipped with an optical fiber was attached to the side of the package.

By using such an optical communication module, an optical signal introduced / derived by the optical fiber in the ferrule can be converted into an electric signal by the photoelectric conversion element in the package.

In the case of manufacturing the above optical communication module, first, an electric element and a photoelectric conversion element are mounted in a package, and then a ferrule equipped with an optical fiber is inserted into a side surface of the package to convert the photoelectric conversion element. The optical axis is aligned with and joined.

[0005]

However, when manufacturing the above-mentioned optical communication module, it is necessary to mount the photoelectric conversion element and the electric element in a narrow space inside the package, which is troublesome for the mounting work. There was a problem.

Also, after the above-mentioned various elements are mounted, when the ferrule which is the optical signal transmission member is joined, the optical axis alignment with the photoelectric conversion element is performed in a narrow space in the package, which is troublesome. There was a problem of this.

Further, although the electric element in the package is covered with a sealing material such as resin, there is a problem that the loss of a high frequency signal is large because the dielectric constant of the resin is generally high.

[0008]

Therefore, the present invention provides an optical communication module having a photoelectric conversion element and an electric element built in a package, and an optical signal transmission system for the photoelectric conversion element. And a photoelectric conversion element are joined together via an optical system frame.

Further, according to the present invention, in manufacturing the optical communication module, first, the photoelectric conversion element and the optical signal transmission member are joined together with their optical axes aligned with each other through an optical system frame, and then, The photoelectric conversion element is fixed to a substrate provided with an electric element, covered with a case, and hermetically sealed.

That is, according to the present invention, since the optical signal transmission member and the photoelectric conversion element are first bonded to each other through the optical system frame, it is not necessary to work in a narrow space in the package. The operation of aligning the optical axes and joining them can be easily performed. Next, the photoelectric conversion element is fixed to a substrate separately provided with an electric element, but at this time, it is sufficient to simply bond the photoelectric conversion element.

Further, the present invention is characterized in that the above-mentioned electric element is bonded onto a substrate constituting an electric circuit via a space layer.

That is, since air has a very low dielectric constant of 1, it is possible to prevent high frequency signal loss by interposing a space layer having a low dielectric constant between the electric element and the substrate.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a photoelectric conversion element 1 such as a laser diode or a photodiode is coupled to an element stem 2 and fixed to a horizontal portion 3a of an optical system frame 3 made of metal or ceramics having an L-shaped cross section. Has been done. Further, a lens 4 is fixed to the vertical portion 3b of the optical system frame 3 as an optical signal transmission system, and a ferrule holding member 5 and an end portion thereof on the photoelectric conversion element 1 side. On the other hand, a ferrule 6 including an optical fiber is inserted and held at the end of the ferrule holding member 5 opposite to the lens 4.

Here, although the ferrule holding member 5 is merely a cylindrical member in FIG. 1, it is actually a ferrule 6.
It includes a sleeve for inserting, a ferrule stopper for axial positioning, a body for holding these, and the like. Further, the ferrule 6 can be fixed to the ferrule holding member 5 to form a pigtail type, or the ferrule 6 can be attached to and detached from the ferrule holding member 5 to form a receptacle type.

The optical signal transmission system for the photoelectric conversion element 1 is a series of members for transmitting an optical signal to the photoelectric conversion element 1. In FIG. 1, the lens 4, the ferrule holding member 5, and the ferrule 6 are shown. Refers to. In addition, the lens 4
Instead of the above, a ferrule (fiber stub) in which an optical fiber is embedded may be provided, or the ferrule 6 on the optical connector side may be extended as it is to form an optical signal transmission system.

On the other hand, an electric element 9 such as an IC chip is electrically connected and mounted on a ceramic substrate 8 forming an electric circuit, and the periphery thereof is made of resin such as silicon paste or resin for humidity sealing. It is covered with the sealing material 10. The photoelectric conversion element 1 and the electric element 9 are fixed on the substrate 8 by fixing the optical system frame 3 to which the photoelectric conversion element 1 is fixed and further covering with a case 7 made of metal or ceramics.
To form an airtight package.

The photoelectric conversion element 1 and the electric element 9 are electrically connected to each other, and an electric signal can be inputted / outputted from a lead portion (not shown) provided on a substrate 8 forming an electric circuit. Therefore, the optical signal introduced / derived by the optical fiber provided in the ferrule 6 on the optical connector side can be converted into an electrical signal by the photoelectric conversion element 1, and the optical communication module can be operated.

Next, a method of manufacturing the optical communication module of the present invention will be described.

First, as shown in FIG. 2A, the photoelectric conversion element 1 and the element stem 2 are provided on the horizontal portion 3a of the optical system frame 3.
After coupling, the ferrule holding member 5 and the lens 4 are fixed to the vertical portion 3b of the optical system frame 3 while aligning the optical axes. At this time, the ferrule 6 having an optical fiber is inserted and held at the end of the ferrule holding member 5 opposite to the lens 4, and the photoelectric conversion element 1 is emitted while emitting an optical signal from the optical fiber. The position may be adjusted so that the optical coupling with respect to is maximized. This work does not have to be performed in a narrow space inside the package, and can be easily performed.

Next, as shown in FIG. 2B, an electric element 9 is mounted on a substrate 8 forming an electric circuit, and a sealing material 10 is formed.
Then, the optical system frame 3 is bonded onto this substrate and further covered with a case 7 to hermetically seal. At this time, since the electric element 9 may be mounted on the substrate 8, the electric device 9 can be easily worked, and the substrate 8 and the optical system frame 3 can be mounted.
Since the case 7 and the case 7 need only be joined, the assembling work can be easily performed.

In the above embodiment, the optical system frame 3
Although an L-shaped one is used as this, this shape can be freely changed according to the structure of the module and the like.

In the present invention, the joint structure between the substrate 8 and the electric element 9 is also important. That is, in the conventional structure, as shown in FIG.
As shown in FIG. 3, the electric element 9 was placed in close contact with the substrate 8 and connected to the electric circuit by the connection member 11 by wire bonding, and covered with the sealing material 10. Therefore, the vicinity of the electric element 9 is made of a material having a high dielectric constant such as the ceramic substrate 8 and the resin sealing material 10, and the high frequency signal is easily attenuated.

On the other hand, in the present invention, as shown in FIG.
A connecting member 11 such as a ball bonder is provided at a predetermined position on the substrate 8.
The electrical element 9 is electrically connected and held by the space layer 12 having a width of about 80 μm formed between the electrical element 9 and the substrate 8. When the electric element 9 is covered with the sealing material 10, the sealing material 10 is prevented from entering the space layer 12.

Therefore, air having a low dielectric constant exists between the electric element 9 and the substrate 8, and it is possible to prevent the attenuation of the high frequency signal.

[0026]

As described above, according to the present invention, in the optical communication module including the photoelectric conversion element and the electric element in the package and including the optical signal transmission system to the photoelectric conversion element, the optical signal transmission is performed. By bonding the system and the photoelectric conversion element via the optical system frame, when manufacturing the optical communication module, first, the optical signal transmission system and the photoelectric conversion element are mutually connected via the optical system frame. By aligning and joining the optical axes, there is no need to work in a narrow space inside the package, so the aligning and aligning the optical axes can be easily performed, and then a separate electric element can be added. It can be easily manufactured by fixing the photoelectric conversion element to the provided substrate and covering it with a case.

Further, according to the present invention, the above electric element is
Since the space layer having the low dielectric constant is interposed between the electric element and the substrate through the space layer, it is possible to prevent the loss of the high frequency signal.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing an optical communication module of the present invention.

2A and 2B are cross-sectional views for explaining a manufacturing process of the optical communication module of the present invention.

FIG. 3 is a vertical cross-sectional view showing a structure for fixing an electric element in a conventional optical communication module.

FIG. 4 is a vertical sectional view showing a fixing structure of an electric element in the optical communication module of the present invention.

[Explanation of symbols]

 1: Photoelectric conversion element 2: Element stem 3: Optical system frame 4: Lens 5: Ferrule holding member 6: Ferrule 7: Case 8: Substrate 9: Electric element 10: Sealing material 11: Connection member 12: Space layer

Claims (3)

[Claims] 1. An optical communication module comprising a photoelectric conversion element and an electric element in a package, and an optical signal transmission system to the photoelectric conversion element, wherein the optical signal transmission system and the photoelectric conversion element are an optical system frame. A module for optical communication that is bonded via 2. The electric element is mounted on a substrate forming an electric circuit via a space layer.
The optical communication module described. 3. An optical signal transmission system and a photoelectric conversion element, which have been previously adjusted in optical axis, are joined together by aligning their optical axes with each other through an optical system frame, and then the photoelectric conversion element is connected to an electric element. A method for manufacturing an optical communication module, which comprises the steps of fixing on a provided substrate, covering with a case and hermetically sealing.