JP2001242355A - Optical module and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide high-efficiency optical coupling by simplifying component members and further simplifying optical coupling characteristics. SOLUTION: A polarization plane maintaining optical fiber 11 and an optical semiconductor element 12 for executing light emission or light reception to be optically coupled to one end of the polarization plane maintaining optical fiber 11 are housed via an adhesive material 16 allowing the transmission of light into a package 32 in the state of fixing the optical coupling portion relation between both.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical module used for optical fiber communication, and more particularly to an optical module in which an optical fiber and an optical semiconductor element are optically coupled, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In configuring an optical communication system, an optical module for optically coupling an optical semiconductor element and an optical fiber is known as one of important devices.

Conventionally, in order to optically couple an optical semiconductor device such as a semiconductor laser and an optical fiber, it is necessary to align the positional relationship with an accuracy of the order of μm, which has required a large number of man-hours. . For this reason, a method of determining the optical axis position without adjustment has been proposed as a means for reducing the number of alignment steps. For example, by mounting and fixing an optical semiconductor element and an optical fiber on a silicon substrate in which the mounting position of the optical semiconductor element and the position of the V groove are positioned with high precision, the relative position of the optical semiconductor element and the optical fiber can be adjusted without adjustment. A method for deciding is proposed (JP-A-6-3373).
No. 33).

[0004]

In the optical module as described above, it is necessary to manufacture a silicon substrate to be used with an accuracy of the order of μm. The silicon substrate can be formed with high-precision irregularities by anisotropic etching, but the electrode pad for mounting the optical semiconductor element is formed by a photo process, and the optical fiber abutment groove that defines the optical axis direction is dicing. In order to use such means, the unevenness and the relative position formed with high precision by etching
It is difficult to specify by order. In addition, it is difficult to manufacture a silicon substrate at low cost because of a complicated process.

When mounting an optical semiconductor device, the relative position is detected by recognizing the marker formed on the optical semiconductor device and the silicon substrate. Among the optical semiconductor devices, an edge-emitting semiconductor laser or the like emits light. Since the end is formed by cleavage, the positional relationship between the marker provided on the optical semiconductor element and the emitting end also varies, causing a variation in accuracy after mounting.

In mounting an optical semiconductor device on a silicon substrate formed with high precision, the mounting position accuracy also varies on the order of μm, and the relative position accuracy between the optical semiconductor device and the optical fiber in a fixed optical module. Cannot avoid that each variation is piled up to several μm.

Further, these means can be used only for an optical semiconductor device of an end face light receiving / emitting type.
Incident type optical semiconductor devices, such as surface emitting lasers and PDs
(Photodiode) is not suitable for mounting.

The present invention has been made in view of the above-mentioned problems in the prior art, and has as its object to provide a high-efficiency optical coupling at a low cost by simplifying the components and further improving the optical coupling characteristics. It is in.

[0009]

According to an optical module of the present invention, a polarization-maintaining optical fiber and an optical semiconductor device for emitting or receiving light that is optically coupled to one end of the polarization-maintaining optical fiber transmit light. It is housed in a package in a state where the optical coupling positional relationship between the two is fixed via an adhesive material. That is, in an optical module in which a package contains one end of a polarization-maintaining optical fiber and an optical semiconductor element that emits or receives light that is optically coupled to one end of the polarization-maintaining optical fiber, An optical coupling portion between one end of the optical fiber and the optical semiconductor element is fixed by an adhesive that transmits light.

Further, the optical semiconductor element is a surface emitting type light emitting element or a surface light receiving type light receiving element. The adhesive is, for example, an epoxy-based or acrylic-based ultraviolet curable resin or a thermosetting resin.

Further, according to the manufacturing method of the present invention, the one end of the optical fiber and the light emitting surface or the light receiving surface of the optical semiconductor element which emits or receives light are held in a predetermined positional relationship. An adhesive made of an ultraviolet-curable resin or a thermosetting resin is applied to the optical coupling portion with the optical semiconductor element, and then the adhesive is solidified by irradiating or heating the ultraviolet-ray, and one end of the optical fiber, The optical semiconductor element is fixed to one end of the fiber via an adhesive and housed in a package.

[0012]

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

As shown in FIG. 1, an optical module M according to the present invention comprises, in a package 32, one end of an optical fiber 11 and an optical semiconductor element 12 for emitting or receiving light, which is optically coupled to one end of the optical fiber 11. Are accommodated at least.

Here, an optical coupling portion between one end of the optical fiber 11 and the optical semiconductor element 12 is fixed by a light transmitting adhesive 16. A conductor for conducting to the optical semiconductor element 12 is formed on the chip carrier 13 on which the optical semiconductor element 12 is mounted, and is electrically connected to a lead 31 provided on the chip carrier 13. Optical fiber 1
An optical fiber 1 having anisotropy, that is, a polarization-maintaining optical fiber (a panda fiber or an elliptical core fiber) can be suitably used because its directivity can be determined by observing the exit end.

Various semiconductor lasers, LED arrays, PDs and the like can be used as the optical semiconductor element 12. Particularly, by using a surface-emitting / light-receiving optical semiconductor element, compared with the case of using an edge-emitting device. As a result, the mounting density can be increased, and a small and highly integrated module can be formed.

Also, by using an optical fiber having anisotropy as the optical fiber, it is possible to form a polarization-dependent module by defining the fiber direction according to the polarization of light emitted from the optical semiconductor device. It becomes possible.

Further, an epoxy-based, acrylic-based, or silicone-based photocurable resin or a thermosetting resin is used as the adhesive. Particularly, epoxy-based and acrylic-based resins can be suitably used because of their high hardness. . Further, as described later, it is particularly preferable that the ultraviolet curable type is used because it is hardly exposed in a daily environment and can be cured in a short time.

Next, the mounting method of the present invention will be specifically described. In the present invention, by observing the positional relationship between the optical fiber and the optical semiconductor element at the same time, the adhesive is applied and cured after correcting the positional relationship. As a result, when an optical fiber and an optical semiconductor device are mounted by determining the position with respect to the marker on the submount which originally has a slight positional shift as in the related art, the position other than the positional shift recognized by the mounting apparatus is generated. This eliminates the misalignment between the optical fiber and the optical semiconductor element. As a result, the alignment between the optical fiber and the optical semiconductor element can be performed with high yield.

Further, since it is possible to use light curing as a means for curing the adhesive, the mounting process can proceed more quickly than when the adhesive is cured by heat. In particular, the alignment of the optical fiber and the optical semiconductor element requires an accuracy on the order of sub-μm, and a short curing time directly leads to the assurance of the accuracy. In addition, since bonding can be performed by light irradiation, there is no need to expose the entire module to a high temperature.

Further, by using ultraviolet curing as a means for curing the adhesive, it is possible to work in an environment where ordinary photocurable resin is exposed to light. In addition, by using thermosetting for the adhesive curing means,
It is possible to harden areas that are not exposed to light structurally,
Sufficient fixing strength can be maintained when a structural agent other than the adhesive is interposed.

Also, means for observing and recognizing the end face of the optical fiber, means for observing and recognizing the shape of the outgoing and incident surfaces of the optical semiconductor element, and based on the relative positional relationship obtained from these two observing means. Means for moving the optical fiber and the optical semiconductor element to an optimal positional relationship, and means for applying an adhesive between the optical fiber and the optical semiconductor element, and means for curing the adhesive. In addition, it is possible to manufacture an optical module without misalignment between the optical fiber and the optical semiconductor element, and it is possible to perform the alignment between the optical fiber and the optical semiconductor element with high yield.

Further, by providing a light irradiating device as a means for curing the adhesive, it is possible to cure the adhesive in a short time, shorten the production time, and maintain accuracy while maintaining the precision. The steps that are not required can be performed in a short time, and an optical module with a high yield can be manufactured.

Further, since the optical fiber and the optical semiconductor element maintain the positional relationship by the adhesive, the degree of freedom of the relative positional relationship can be increased. Conventionally, each element such as an optical fiber and an optical semiconductor element is fixed to a fixing member such as a chip carrier, so that the degree of freedom of the arrangement is limited. However, the present invention can eliminate the restriction.

The use of a photo-curable resin as an adhesive for fixing makes it possible to shorten the time required for the fixation. In particular, by using an ultraviolet-curable resin, the surrounding area can be reduced in a normal state. The resin is not cured by the light scattered in the resin, and the deterioration after curing is suppressed to be smaller than that of a normal visible light curable resin.

FIG. 2 is a perspective view showing an example of the optical module mounting method of the present invention. In FIG. 2, reference numeral 11 denotes an optical fiber such as a polarization-maintaining optical fiber, 12 denotes an optical semiconductor element (here, a semiconductor laser), 13 denotes a chip carrier,
Reference numeral 4 denotes a camera provided with two CCDs above and below. The optical fiber 11 and the optical semiconductor element 12 are each fixed by a fine movement stage. The camera 14 can observe the top and bottom simultaneously by the above configuration.

First, the optical fiber 11 and the optical semiconductor element 1
2 are arranged at positions facing each other. The camera 14 includes an optical fiber 11 and an optical semiconductor element 12 as shown in FIG.
The pattern on the surface is recognized as an image inserted between the images.

FIG. 4 shows a state in which this is observed from the cross-sectional direction.
(A) to (c) are shown. In FIG. 4A, reference numeral 21 denotes a fiber measurement side camera, and its observation pattern is as shown in FIG. 4B. 4A is a semiconductor laser measurement side camera, and FIG. 4C shows an observation pattern thereof. 4 in FIG. 4B represents the core of the optical fiber, and 24 in FIG. 4C represents the core of the semiconductor laser.

In the optical module, in order to obtain a desired optical coupling, it is necessary to precisely position the relative positional relationship between the optical fiber core 23 and the semiconductor laser core 24.
By adopting such a configuration, the relative position between the optical fiber core 23 and the semiconductor laser core 24 is determined by directly observing the positional relationship between them, and the relative position is determined at a predetermined position designed by the fine movement stage to which each member is attached. Move and arrange.

After this arrangement, the camera 14 is retracted to a position as shown in FIG. 2, and the optical fiber 11 and the optical semiconductor element 12 are brought closer. In the observation by autofocus of the camera 14, the optical fiber 11 and the optical semiconductor element 1
The vertical positional relationship between the optical fibers 11 and the optical semiconductor elements 12 can be arranged with predetermined accuracy according to the design.

Next, an ultraviolet curable adhesive 16 is filled by the dispenser 15 shown in FIG. 2 so as to surround the optical fiber 11 and the semiconductor laser 12. The adhesive material 15 is adjusted to have an appropriate viscosity (1000 CPS or more) that does not flow out.

Next, as shown in FIG. 2, ultraviolet rays 18 are radiated from an ultraviolet ray irradiating device 17 as an adhesive curing means toward the previously applied adhesive 16. Thus, the optical fiber 11 and the semiconductor laser 12 can be fixed at predetermined positions.

The above is merely an example of the embodiment of the present invention, and the present invention is not limited to the embodiment. Various changes and improvements can be made without departing from the spirit of the present invention.

[0033]

As described above, according to the optical module and the method of manufacturing the same of the present invention, the core of the optical fiber and the emission end of the optical semiconductor element are directly observed and aligned, and the two elements are bonded by the adhesive. By sticking, conventionally,
An extra misalignment caused by the indirect member can be omitted, and the optical fiber and the optical semiconductor element in the optical module can be mounted with high accuracy.

Further, since it is possible to omit all excess misalignment, the tolerance of optical coupling can be relaxed, and the optical module can be manufactured with high yield and at low cost.

Further, it is not necessary to use a high-precision substrate for mounting an optical semiconductor element which has been conventionally used, and a surface-emitting / light-receiving type which has been difficult in conventional module mounting which has been performed on a flat substrate. On the device,
Since the present invention can be applied without any problem,
The effects of high density and miniaturization of the optical module can be greatly expected.

[Brief description of the drawings]

1A and 1B are diagrams schematically illustrating an optical module according to the present invention, wherein FIG. 1A is a perspective view showing a state before an optical semiconductor element is housed in a package, and FIG. It is a perspective view.

FIG. 2 is a perspective view schematically illustrating a method for manufacturing an optical module according to the present invention.

FIG. 3 is a perspective view schematically illustrating a method for manufacturing an optical module according to the present invention.

4A and 4B are diagrams for schematically explaining a method for manufacturing an optical module according to the present invention, wherein FIG. 4A is a side view, FIG. 4B is a front view on the optical fiber side, and FIG. FIG.

[Explanation of symbols]

 11: Optical fiber 12: Optical semiconductor device (semiconductor laser) 13: Chip carrier 14: Camera 15: Dispenser 16: Adhesive 17: Ultraviolet irradiation device 18: Ultraviolet 32: Package M: Optical module

Claims (4)

[Claims] 1. An optical module comprising: a package containing an end of a polarization-maintaining optical fiber and an optical semiconductor element for emitting or receiving light, which is optically coupled to one end of the polarization-maintaining optical fiber. An optical module, wherein an optical coupling portion between one end of the polarization-maintaining optical fiber and the optical semiconductor element is fixed by an adhesive that transmits light. 2. The device according to claim 1, wherein the optical semiconductor device is a surface-emitting type light-emitting device or a surface-receiving type light-receiving device.
An optical module according to item 1. 3. The optical module according to claim 1, wherein the adhesive is an ultraviolet curing resin or a thermosetting resin. 4. An optical fiber device according to claim 1, wherein one end of the optical fiber and the light emitting surface or the light receiving surface of the optical semiconductor element for emitting or receiving light are held in a predetermined positional relationship. An optical coupling portion is coated with an adhesive made of an ultraviolet-curable resin or a thermosetting resin, and then solidified by irradiating or heating the adhesive with ultraviolet light, and one end of the optical fiber and the optical fiber. A method for manufacturing an optical module, wherein the optical semiconductor element is fixed to one end via an adhesive and housed in a package.