JPH07218758A - Package structure for mounting optical waveguide - Google Patents

Abstract

PURPOSE:To sufficiently prevent moisture from entering a housing. CONSTITUTION:The package structure is constituted by putting silicone materials 11 and 13 with V grooves, a waveguide substrate 12 which has plural optical waveguides, etc., in the housing 10. Those silicone materials 11 and 13 with the V grooves and the waveguide substrate 12 are integrated into one body by fixing their opposite end surfaces with a UV adhesive, and the whole body is covered with silicone gel 16 which buffers a shock. The gap between the silicone gel 16 and housing 10 is filled with epoxy resin 19 which has higher airtightness than the silicone gel 16 to sufficiently prevent water entering the adhesion part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package structure for mounting an optical waveguide used for branching an optical signal or the like.

[0002]

2. Description of the Related Art A conventional package structure for mounting an optical waveguide is shown in FIG. This package structure has
Silicon 3 with V-groove that supports and fixes the input fiber 34
1, a waveguide substrate 32 having a plurality of optical waveguides, a V-grooved silicon 33 that supports and fixes an output fiber 35, and the like are housed, and each member is integrated in an optical axis aligned state at each connection end face. Are joined together. A cushioning protection material 36 is filled between the housing 30 and the V-grooved silicon 31, 33 and the waveguide substrate 32, and the cushioning protection material 36 absorbs an external impact. Has become. In addition, in the fiber penetration portions 37 at both ends,
Epoxy resin 38 that is more airtight than the cushioning protection material 36
To prevent moisture from entering the inside of the housing 30.

A package structure of this type is also disclosed in Japanese Unexamined Patent Publication No. 5-27139.

[0004]

However, with the package structure shown in FIG. 3, it has not been possible to sufficiently prevent moisture from entering the inside of the housing 30. For this reason, the adhesive (ultraviolet curing type) between the V-grooved silicon 31, 33 and the waveguide substrate 32 absorbs moisture, resulting in a decrease in adhesive strength over time, a decrease in light transmittance, and a remarkable decrease. In this case, there was a defect that the V-grooved silicon 31, 33 and the waveguide substrate 32 were separated.

The present invention has been made to solve such a problem, and an object thereof is to prevent adhesive from adhering to the end face of the waveguide substrate by sufficiently preventing moisture from entering the inside of the housing. An object of the present invention is to provide a package structure for mounting an optical waveguide, which prevents deterioration and has excellent environment resistance and high reliability.

[0006]

Therefore, the package structure for mounting an optical waveguide according to the present invention has an input fiber support that supports and fixes an input fiber that guides an optical signal, and an optical axis at one end of the input fiber support. An output fiber that is aligned and spliced and has an optical waveguide that guides the optical signal emitted from the input fiber, and an optical fiber that is optical-axis aligned and spliced to one end of the waveguide substrate and that guides the optical signal emitted from the optical waveguide. The output fiber support that supports / fixes the input fiber support, the waveguide substrate, and the output fiber support as a whole, and a buffer protection material that protects them from external stress, and a coating with this buffer protection material The housing for accommodating the input fiber support, the waveguide substrate and the output fiber support, and the buffer protection material are filled between the housings and have a higher airtightness than the buffer protection material. There configure a filler.

In this case, it is preferable that the buffer protective material is a silicone gel and the filler is an epoxy resin.

[0008]

In this package structure, the joint between the input fiber support and the waveguide substrate and the joint between the waveguide substrate and the output fiber support are weak against external stress. This area is protected from external stress by covering it with a relatively soft cushioning material such as silicone gel.

Further, the input fiber support, the waveguide substrate and the output fiber support are entirely covered with a cushioning protective material, and a highly airtight filler is filled between the cushioning protective material and the casing. So, the water (steam) existing in the external atmosphere
Are prevented from reaching the adhesive at this joint.

Further, since the input fiber support, the waveguide substrate and the output fiber support are entirely covered with the cushioning protective material, even when the filler existing on the outer side is thermally expanded, the stress due to this expansion is generated. , Directly to each support and the waveguide substrate.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a longitudinal section of a package structure for mounting an optical waveguide according to this embodiment. In this package structure, inside the housing 10, V-grooved silicon 11 that supports / fixes the input optical fiber 14, a waveguide substrate 12 having a plurality of optical waveguides, and V-grooved silicon 13 that supports / fixes the tape fiber 15 are provided. It is configured to accommodate such as.

The casing 10 is formed of an epoxy resin having high strength and a small shrinkage factor upon curing, and has a function of stabilizing environmental resistance and buffering a mechanical shock. A fiber penetrating portion 10a having a smaller diameter than that of the central portion is formed to project at both ends of the housing 10, and a protective tube 17 for protecting the fiber is provided at the tip of the fiber penetrating portion 10a. A sleeve 18 made of rubber is attached to the portion.

FIG. 2 is a plan view showing the V-grooved silicon 11, 13 and the waveguide substrate 12 taken out. V
The grooved silicon 11 supports / fixes a single or a plurality of input optical fibers 14, and a UV adhesive (ultraviolet curing type) 20 is used to attach the incident side end surface of the waveguide substrate 12 to the optical axis. It is fixed in an aligned state. The waveguide substrate 12 is formed with a large number of optical waveguides for branching the optical signal incident from the input optical fiber 14 into a plurality of optical signals, and in the example shown in the figure, the incoming optical signal is branched into eight. The V-grooved silicon 13 supports and fixes an 8-core optical fiber that is optically coupled with each optical waveguide of the waveguide substrate 12, and each optical fiber constitutes an 8-core tape fiber 15.

Then, as shown in FIG. 1, the entire V-grooved silicon 11, 13 and the waveguide substrate 12 are covered with a silicone gel 16. This silicone gel 1
Since 6 is relatively soft, it has a function of buffering a mechanical shock applied from the outside. It should be noted that coating the entire surface with the silicone gel 16 in this manner is effective in the following points. That is, although an epoxy resin 19 described later is present outside the silicone gel 16, even when the epoxy resin 19 thermally expands, the stress can be absorbed to some extent by the silicone gel 16. , 13 and the waveguide substrate 12 can be prevented.

The V-grooved silicones 11 and 13 coated with the silicone gel 16 and the waveguide substrate 12 are housed inside the casing 10 between the casing 10 and the silicone gel 16 as described above. An epoxy resin 19 having higher airtightness than the silicone gel 16 is filled. The epoxy resin 19 is also filled in the fiber penetrating portions 10a at both ends of the housing 10 that are directly exposed to the outside atmosphere. By filling the inside of the housing 10 with the highly airtight epoxy resin 19 in this manner, it is possible to sufficiently prevent water from entering the inside of the housing 10.

Next, the following comparative tests were carried out. First, a wet heat test was performed in which the package structure shown in FIG. 1 was exposed to an atmosphere of a temperature of 75 ° C. and a humidity of 95% for two weeks. Separately from this test, a water immersion test was conducted in which the package structure shown in FIG. 1 was immersed in water having a water temperature of 43 ° C. for 1 week. As a result, the yield was 100% in all cases.

Further, the conventional package structure of FIG. 3 was subjected to a wet heat test and a water immersion test under the same conditions. As a result, the yield was about 50% in all cases. From this, it was confirmed that the package structure of the present embodiment was able to sufficiently prevent moisture from entering the housing 10.

In this embodiment, silicone gel is used as an example of the cushioning protective material for protecting the joint portion formed by the adhesive, but in addition to this, flexible epoxy, urethane rubber,
Alternatively, silicon rubber or the like can be used. Also,
As the filler having higher airtightness than the cushioning protective material, an epoxy resin is exemplified, but in addition to this, a flexible epoxy,
Urethane rubber, silicone rubber, or the like can be used.

Further, in the present embodiment, the function of the waveguide substrate 12 is exemplified to branch the incident optical signal, but the function of the waveguide substrate is particularly limited, for example, switching of the optical waveguide. is not.

[0021]

As described above, according to the packaging structure for mounting an optical waveguide according to the present invention, the input or output fiber support and the waveguide substrate are covered with a buffer protective material for protecting them from external stress, Moreover, a structure is adopted in which a space between the outer peripheral portion and the housing is filled with a filler having a higher airtightness than the cushioning protective material. Therefore, it is possible to have sufficient strength against the stress acting from the outside and to sufficiently prevent the intrusion of moisture from the outside. As a result, it is possible to prevent a decrease in adhesive strength and a decrease in light transmission, which are caused by the absorption of the adhesive at each joint, and a highly reliable environment-resistant package for mounting an optical waveguide. Can provide structure.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a package structure for mounting an optical waveguide according to the present embodiment.

FIG. 2 is a plan view showing the V-grooved silicon, the waveguide substrate, and the like housed in the housing of FIG.

FIG. 3 is a vertical cross-sectional view showing a conventional package structure.

[Explanation of symbols]

Reference numeral 10 ... Housing, 11 ... Silicon with V groove (input fiber support), 12 ... Waveguide substrate, 13 ... Silicon with V groove (output fiber support), 16 ... Silicone gel (buffer protection material), 19 ... Epoxy Resin (filler).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Oi Oi, 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (72) Shinji Ishikawa 1 Taya-cho, Sakae-ku, Yokohama, Kanagawa Sumitomo Electric Industry Co., Ltd. Yokohama Works

Claims (2)

[Claims] 1. A waveguide substrate comprising an input fiber support for fixing an input fiber for guiding an optical signal, and an optical waveguide joined to one end of the input fiber support for guiding the optical signal emitted from the input fiber. An output fiber support that is joined to one end of the waveguide substrate and fixes an output fiber that guides the optical signal emitted from the optical waveguide; and the input fiber support, the waveguide substrate, and the output fiber support. A buffer protective material that covers the whole and protects them from externally applied stress, and a housing that is coated with the buffer protective material and that internally houses the input fiber support, the waveguide substrate, and the output fiber support. A package structure for mounting an optical waveguide, comprising: a filling material filled between the buffer protection material and the housing and having a higher airtightness than the buffer protection material. 2. The buffer protective material is a silicone gel,
The package structure for mounting an optical waveguide according to claim 1, wherein the filler is an epoxy resin.