JP3431769B2 - Method of manufacturing waveguide type optical transmission module and method of manufacturing airtight cap used therein - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical transmission module,
Especially waveguide-type optical transmission module mounted with light emitting elements or light receiving elements on a glass waveguide manufacturing method, and to
The present invention relates to a method for manufacturing an airtight cap used .

[0002]

2. Description of the Related Art A waveguide type optical transmission module in which a light emitting element and a light receiving element are mounted on a glass waveguide is drawing attention as a transmission module for optical communication of an optical subscriber system and a trunk line system in the near future.

FIG. 3 shows the structure of a conventional waveguide type optical transmission module. A part of the glass waveguide 4 in which the core 2 and the cladding 3 made of quartz glass are formed on the silicon substrate 1 is removed by etching to form a pit 6 for mounting a light emitting element or a light receiving element 5.

The light emitting element or the light receiving element 5 is mounted in the pit 6 and is optically coupled to the core 2 of the glass waveguide 4. The light emitting element or the light receiving element 5 is electrically coupled to a metal film called an electrode pad 8 formed on the cladding 3 of the glass waveguide 4 by wire bonding 7.

A semiconductor laser is usually used as the light emitting element. Further, a photodiode is usually used as the light receiving element. Since these semiconductor elements are corroded and deteriorated by the moisture contained in the atmosphere, the airtight cap 9 is put on the pit 6 for the purpose of avoiding contact with the outside air. The airtight structure by the airtight cap 9 is shown in FIG.

The electrode pad 8 is composed of a semiconductor element lower electrode 8a inside the pit 6, a semiconductor element upper electrode 8b and two electrodes 8c and 8d on the waveguide 4. The upper and lower electrodes 8b and 8a of the semiconductor element 5 are respectively formed. 2 on the waveguide 4
The two electrodes 8d and 8c are connected by wire bonding 7. The semiconductor element 5 and the lower electrode 8a are bonded by solder 16.

The airtight cap 9 has a concave box shape so as not to come into contact with the semiconductor element 5 and the wire bonding 7 inside, and is fixed on the glass waveguide 4 with an adhesive 10. The material of the airtight cap 9 is metal, glass, ceramic or the like having no moisture permeability, and the recess is formed by machining. Airtight cap 9
For the attachment, the adhesive 10 is applied to the airtight cap 9, and the adhesive 10 is placed on the glass waveguide 4 and then cured. Adhesive 10
As such, an ultraviolet curable or thermosetting epoxy resin or acrylic resin is used.

[0008]

It is necessary to provide a recess in the airtight cap 9, and this recess is conventionally formed by machining. Therefore, the cost of the cap itself becomes high, and as a result, the cost of the waveguide type optical transmission module is high. In addition, the attachment method also needs to apply adhesive, which requires application time, and if the amount of adhesive is not properly controlled, excess adhesive will flow into the pits, which will reduce product yield and reliability. Cause
As a result, there is also a problem that the cost of the waveguide type optical transmission module is high.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and provide a low cost and highly reliable waveguide type optical transmission module.

[0010]

According to a first aspect of the present invention, a glass waveguide having a core and a clad is partially removed to form a pit portion, and a semiconductor element is mounted on the pit portion. In the method for manufacturing a waveguide type optical transmission module in which an airtight cap is mounted so as to cover the pit portion, the airtight cap is a flat plate made of a brittle material,
Form a thermoplastic resin coating, and on the thermoplastic resin coating
A mask material for forming a plurality of recesses is applied,
Sand blast that sprays hard sand grains on the surface of wood
Machining to form multiple recesses in unmasked areas
After forming, remove the mask material and cut into small pieces containing the recess.
Created by cutting, arrange the airtight cap in the pit portion of the glass waveguide so that the surface of the thermoplastic resin coating of the airtight cap faces the glass waveguide, and apply a load to the airtight cap. While heating, the airtight cap is bonded to the glass waveguide.

[0011] According to a second aspect of the invention, a waveguide-type optical transmission
Method for manufacturing airtight cap used in module
A flat plate made of a brittle material is formed with a thermoplastic resin film, a mask material for forming a plurality of recesses is formed on the thermoplastic resin film, and the surface provided with the mask material is Sandblasting is performed by spraying hard sand grains to form multiple recesses in the unmasked area, then the mask material is removed and cut into small pieces containing the recesses.
Especially .

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 shows a method of manufacturing an airtight cap used in the waveguide type optical transmission module of the present invention. First, as shown in FIG. 1A, an ethylene-based copolymer resin, which is a thermoplastic resin, is melted in a solvent xylene, coated on a glass flat plate 11 and then dried to form a thermoplastic resin coating film 12. A metal plate having a plurality of punched holes is brought into close contact therewith as a mask material 13.

[0013] Next, as shown in FIG. 1 (b), blowing sand hard from above the mask material 13 to sandblasting. By this processing, the unmasked portion is dug.

[0014] Next, as shown in FIG. 1 (c), removing the mask material 13, and a thermoplastic resin with a glass plate 14 having a plurality of recesses. As shown in FIG. 2, the glass plate 14 with a thermoplastic resin having a plurality of recesses formed in this manner is cut into small pieces with a diamond blade 15 to obtain an airtight cap with a thermoplastic resin.

The airtight cap with the thermoplastic resin thus obtained was placed in the pit portion of the glass waveguide and heated to 150 degrees while applying a load of several grams. Could be glued to the glass waveguide.

[0016]

According to the present invention, a thermoplastic resin coating is formed on a flat plate made of a brittle material such as glass, ceramic or silicon, and a plurality of recesses are formed on the thermoplastic resin coating. The mask material is applied, and sand blasting in which hard sand particles are sprayed on the surface on which the mask material is applied, a plurality of recesses are formed in the unmasked portion, and then cut into small pieces containing the recesses. It is possible to manufacture large quantities of airtight caps. The airtight cap and the glass waveguide can be easily bonded only by disposing the above airtight cap on the waveguide and heating.

[0017] Accordingly, installation time to the waveguide path of the airtight cap becomes only minutes minutes to about 50 in the prior art, it is possible to reduce the manufacturing time of the waveguide-type optical transmission module. Moreover, the outflow of excess adhesive resin into the pit portion, which was a problem in the conventional method, is completely eliminated, and the reliability of the optical transmission module can be improved. Since the airtight cap can be manufactured in large quantities at once, the cost of the waveguide type optical transmission module can be significantly reduced.

[Brief description of drawings]

FIG. 1 shows a method for producing a glass plate with a thermoplastic resin having a plurality of recesses according to the present invention.

FIG. 2 shows a method for manufacturing an airtight cap used in the waveguide type optical transmission module of the present invention.

FIG. 3 shows a waveguide type optical transmission module according to the prior art.

FIG. 4 shows an airtight structure of an airtight cap portion of a waveguide type optical transmission module according to a conventional technique.

[Explanation of symbols]

1 Silicon substrate 2 cores 3 clad 4 glass waveguide 5 Light emitting element or light receiving element 6 pits 7 wire bonding 8 electrode pads 9 Airtight cap 10 adhesive 11 glass flat plate 12 Thermoplastic resin coating 13 Mask material 14 Glass plate with thermoplastic resin 15 diamond blade 16 solder 17 recess

Front page continued (72) Inventor Shigeki Ishibashi 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Tatsunori Kanaya 216 Totsuka-cho, Totsuka-ku, Yokohama, Kanagawa Hitachi, Ltd. Mfg. Co., Ltd. Information & Communication Division (72) Inventor Yasunori Iwafuji 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Information & Communication Division (72) Inventor Tatsuo Teraoka 5-1-1 Hidaka-cho, Hitachi City (56) References JP-A-8-166523 (JP, A) JP-A-7-234345 (JP, A) (58) Fields investigated (Int.Cl. ⁷⁾ , DB name) G02B 6/42 G02B 6/122 G02B 6/13

Claims (2)

(57) [Claims] 1. A glass waveguide having a core and a clad is partially removed to form a pit portion, a semiconductor element is mounted on the pit portion, and an airtight cap is attached so as to cover the pit portion. In the method of manufacturing a waveguide type optical transmission module according to claim 1, the airtight cap is made of a brittle material.
A thermoplastic resin coating is formed on a flat plate and the thermoplastic resin coating is applied.
A mask material for forming a plurality of recesses on the film is applied,
Sand that sprays hard sand grains on the masked surface
Blasting is applied to multiple parts on the unmasked area.
After forming the concave portion, the mask material is removed to include the concave portion.
Created by cutting into small pieces, arrange the airtight cap in the pit portion of the glass waveguide so that the surface of the thermoplastic resin coating of the airtight cap faces the glass waveguide, and apply a load to the airtight cap. A method of manufacturing a waveguide type optical transmission module, comprising heating while applying the voltage to bond the airtight cap to the glass waveguide. 2. Use in a waveguide type optical transmission module
A method for manufacturing an airtight cap, comprising forming a thermoplastic resin coating on a flat plate made of a brittle material, and applying a mask material for forming a plurality of recesses on the thermoplastic resin coating, Sandblasting is performed by spraying hard sand particles on the surface of the material, and after forming a plurality of recesses in the unmasked portion, the mask material is removed and cut into small pieces containing the recesses. Characteristic airtight storage
Method of manufacturing-up.