JP2001356245A - Optical module manufacturing method - Google Patents

Abstract

(57) [PROBLEMS] To manufacture a structure for integrating optical components having a large alignment structure such as a guide pin with high yield. SOLUTION: Upper and lower guide groove components 2 and 2a and an optical element mounting substrate 1 are separated from each other, and relative positions of the guide groove components 2 and 2a and the substrate 1 are determined by alignment marks using lithography technology. It is defined by the alignment, and the difficulty in handling at the time of assembling the optical module due to the dimensional difference between the guide pin and the optical element is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical module which enables to manufacture integrated optical components with a high yield.

[0002]

2. Description of the Related Art In a conventional optical module manufacturing method, a hybrid optical module in which an optical semiconductor device and an optical waveguide are integrated is connected to a part of a substrate on which optical components are integrated in order to connect an optical fiber. A structure is provided in which a groove is provided to connect an optical fiber to an optical element or an optical waveguide.

As the optical fiber, a silica-based fiber having a diameter of 125 μm is used. Since the optical fiber itself is fragile, it is necessary to provide a reinforcing structure. For this reason, instead of guiding the optical fiber directly as a guide structure,
The optical fibers were combined into a block having a V-shaped groove, and alignment was realized by guide pins. A typical example of such a structure is an MT connector for connecting fibers.

FIG. 4 shows a conventional example of an integrated optical module having this type of structure, an optical fiber connection structure, and an optical semiconductor element.

[0005] In FIG. 4, the lower substrate 10 has irregularities 10-1, 10-10 processed by anisotropic etching of Si.
Along with 4, a solder film 10-3 for fixing the semiconductor optical element 4 and the guide groove component (substrate with a V-groove) 2 and the like are integrally formed by a photolithography technique used in a semiconductor process.

In FIG. 4, the back side (upper side of the paper) of the substrate 10 is a state where the substrate 2 with the V-groove is placed on the lower side substrate 10, and the front side (lower side of the paper) is the substrate 2 with the V-groove. This is the state before placing. Similarly, the optical waveguide 3 and the optical semiconductor element 4 are also mounted on the substrate 10 along the arrow and fixed by the solder 10-3.

Here, the machining accuracy of the V-shaped grooves 10-1 and 2-1 is extremely high and can be machined with an accuracy of about 0.5 μm. The guide pin 5 is accommodated in a hole defined by the V-shaped grooves 10-1 and 2-1.

However, the guide pins 5 need to have a certain strength, and their dimensions are very large, about several hundred μm, and the grooves 10-1 and 2-1 for accommodating the guide pins 5 are formed in a normal semiconductor process. The groove becomes extremely large as compared with the unevenness that can be handled by the method.

Therefore, the solder film 10 is formed on the uneven substrate 10.
It has been difficult to precisely form the electric wiring 10-5 such as -3 and electrodes. Further, the substrate 10 is provided with a guide groove 10.
-1 and concave portion 10-4 for mounting optical waveguide 3 and optical semiconductor element 4
Are manufactured integrally, and it is difficult to handle at the time of assembling the optical module due to a dimensional difference between the guide pin 5 and the optical waveguide 3 or the optical semiconductor element 4.

4, reference numerals 10-2 denote alignment marks on the substrate 10, 2-2 denotes alignment marks on the V-grooved substrate 2, 2-3 denotes a fixing solder film, and 3-1 denotes a fixing solder film. The optical waveguide core, 3-2, alignment marks on the optical waveguide 3, 4-
Reference numeral 2 denotes an alignment mark on the optical semiconductor element 4.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to manufacture a structure for integrating optical components having a large alignment structure such as a guide pin with a high yield.

[0012]

Basically, by separately providing a component having a guide groove and a component mounted with an optical element, handling at the time of assembling an optical module due to a dimensional difference between the guide component and the optical element. And the relative position between the component having the guide groove and the optical element mounting component is defined by alignment using alignment marks applying lithography technology.

According to a first aspect of the present invention, there is provided a method for manufacturing an optical module, wherein a first alignment mark indicating an optical element mounting position and a second alignment mark indicating a connection position of a guide groove component are formed by photolithography. A third alignment mark indicating the connection position between the guide portion of the guide groove component and the optical element mounting component by making the first and second alignment marks mutually aligned to form an optical element mounting component using A mark is formed in the guide groove part by using a photolithography technique to align the guide portion and the third alignment mark with each other, and an optical element is mounted in accordance with the first alignment mark. Aligning the third alignment mark with the second alignment mark, aligning and connecting the guide groove component to the optical element mounting component, and Characterized in that to adjust the position of the child and the guide groove.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing an optical module according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing an example of a method for manufacturing an optical module, in which arrows in the figure indicate alignment portions of respective optical components, and each component is assembled in accordance with this. FIG. 2 shows a state in which each optical component shown in FIG. 1 is assembled, and each optical component is fixed by solder or an appropriate adhesive. FIG. 3 shows an example in which the end face of the optical component shown in FIG. 2 is inclined obliquely.

1 and 2, in assembling an optical module, an Si substrate 1, which is an optical mounting substrate, an upper V-groove component 2 for guide pins, and a lower V-groove component 2a are used. Is manufactured separately. The upper V-groove part 2 and the lower V-groove part 2a form a pair, and a total of two pairs are used on the back side and the near side.

A mounting portion 1-4 of the optical waveguide 3 and a mounting portion 1-4a of the optical semiconductor element 4 are provided on the upper surface of the Si substrate 1, and a mark 1 for positioning the optical waveguide 3 and the optical element 4 is provided. -2 and a fixing solder film 1-3 are formed.

Further, an MT connector (J
IS C-5981)
Alignment mark 1-2a with upper V-groove component 2 for joining a groove for guiding 0.7 mm guide pin 5
And a fixing solder pattern 1-3a for fixing to the upper V-groove component 2 are provided in the same manner as the optical waveguide mounting section 1-4.

The upper V-groove part 2 has a V
Alignment mark 2-2 between groove 2-1 and Si substrate 1
2-2a for aligning with the lower V-groove component 2a
, And a solder film 2-3 for fixing the Si substrate 1 and the lower V-groove component 2a.

On the lower V-groove component 2a,
In addition to the V-groove 2a-1, a mark 2a-2 (corresponding to the mark 2-2a) for alignment with the upper V-groove component 2, and an upper V
The solder film 2a-3 for fixing to the groove component 2 is formed.

The hollow portion, which is the optical waveguide mounting portion 1-4,
Fabricated with an accuracy of 0.5 μm or less using photolithography technology, particularly anisotropic etching of Si. V groove 2-1;
2a-1 is also 0.5 μm using anisotropic etching of Si.
It was produced with the following accuracy.

Optical waveguide mounting portion 1 for housing optical waveguide 3
The groove depth of the groove 4 is about 20 so as to absorb the difference between the thickness of the cladding of the optical waveguide 3 and the height of the optical element 4 up to the active layer.
It was formed by digging down μm.

The V-groove 2-1 of the upper V-groove component 2 accommodating the guide pin 5 and the V-groove 2a-1 of the lower V-groove component 2a were also etched by about 400 μm using anisotropic etching.
At this time, the interval between the guide pins 5 and the position of the light emitting end face of the optical waveguide 3 match the positions of the guide pins of the MT connector and the light emitting end face of the optical fiber so that the V-groove 2-1 accommodating the guide pins 5 is formed. The shape of 2a-1 was controlled in a photolithography photo process.

Regarding the position where the upper V-groove component 2, the optical waveguide 3 and the optical semiconductor element 4 are mounted, the marks 1-2 for the optical waveguide 3 and the optical semiconductor element 4 are collectively formed on the substrate 1.
Forming a mark 1-2a for the upper V-groove part 2,
Corresponding marks 3-2, 4-2, and 2-2 were formed on each optical component.

At the time of assembling, as shown by arrows in FIG. 1, the components are assembled with the corresponding alignment marks using the above-described alignment marks, and fixed with solder or an adhesive. In the alignment, the alignment mark was recognized by image recognition, and the alignment was performed.

That is, the optical waveguide 3 and the optical semiconductor element 4 are mounted on the substrate 1 with their respective marks 3-2 and 4-2 aligned with the corresponding marks 1-2 on the substrate 1. The upper V-groove component 2 is mounted on the substrate 1 with its mark 2-2 aligned with the mark 1-2a on the substrate 1. Lower V
The groove part 2a has its mark 2a-2 marked on the upper V-groove part 2.
The upper V-groove part 2 is aligned with the upper mark 2-2a.
To be mounted on.

As an example of an assembling order, after the optical semiconductor element 4 is mounted on the substrate 1, the optical waveguide 3, the upper V-groove component 2, and the lower V-groove component 2a are sequentially mounted, and finally the lead frame 6 is mounted.
Was connected to the electrodes 1-5 of the optical semiconductor element 4. Here, the substrate of the lower V-groove component 2a was previously bonded to the substrate of the upper V-groove component 2 to form a guide pin receiving hole.

By the above method, the conventional 400 μm
An optical module could be manufactured by a simple manufacturing process while avoiding processing of solder and electrode patterns on the substrate 10 having m steps.

In the example shown in FIG. 2, with respect to the connection surface (output portion) 7 with the outside of the optical module, the bonding portion with the optical fiber including the input / output end surface of the optical waveguide 3 is vertical.

On the other hand, in the example shown in FIG. 3, with respect to the connection surface 7 of the optical module, the joint portion with the optical fiber including the input / output end face of the optical waveguide 3 is cut out obliquely in advance. Thereby, it is possible to suppress the reflected return light from the module end face.

The optical modules can be connected to each other by, for example, providing an interface of an MT connector. A large-scale optical circuit is divided into individual functions, individually manufactured, and assembled to improve the yield. It becomes possible by manufacturing.

As described above, as a structure for aligning the optical waveguide 3 or the optical semiconductor element 4 with the optical waveguide or the optical fiber on the optical component mounting board, the guide groove components 2 and 2a are formed by the optical component (optical waveguide). Wave path 3 or optical element 4) Separately from mounting substrate 1 and separately manufactured, and later guide groove portions 2, 2
By fixing a on the optical component mounting substrate 1, a portion for realizing positioning of a small device of about 100 μm such as an optical element and an optical fiber, and a light having an outer shape of several hundred μm such as the guide pin 5. A part for guiding a component can be separately manufactured.

Therefore, the guide structure can be integrated with the integrated optical components with a high yield, and not only the yield of the optical components can be improved, but also a large-scale optical component can be realized by combining them. It is extremely useful in reducing.

[0033]

As described above, according to the present invention,
A guide groove component and an optical device mounting component that mounts an optical device such as an optical semiconductor device or an optical waveguide are separated from each other, and the relative positions of the guide groove component and the optical device mounting component are aligned by using lithography technology. By defining the alignment by the method, it is possible to avoid the difficulty in handling at the time of assembling the optical module due to the dimensional difference between the guide component and the optical element, so that the yield is good and the production cost of the optical component is extremely reduced. It is.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a method for manufacturing an optical module according to a first embodiment of the present invention.

FIG. 2 is a view showing a state where the optical component shown in FIG. 1 is assembled.

FIG. 3 is a view showing a component in which an end face of the optical component shown in FIG. 2 is inclined obliquely.

FIG. 4 is a diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Si board (optical mounting board) 1-2, 1-2a Alignment mark 2 Upper V-groove part 2-1 V-groove 2-2, 2-2a Alignment mark 2a Lower V-groove part 2a-1 V-groove 2a -2 alignment mark 3 optical waveguide 3-2 alignment mark 4 optical semiconductor element 4-2 alignment mark 5 guide pin 6 lead frame 7 optical module connection surface

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Motohisa Ishii 2-3-1 Otemachi, Chiyoda-ku, Tokyo F-term in Nippon Telegraph and Telephone Corporation (reference) 2H037 AA01 BA02 BA11 BA24 DA02 DA03 DA11 DA12 2H047 MA07 RA08 TA42

Claims (1)

[Claims] 1. A first alignment mark indicating a mounting position of an optical element and a second alignment mark indicating a connection position of a guide groove component are aligned with the first and second alignment marks using a photolithography technique. The marks are aligned with each other to form an optical element mounting component, and a guide portion of the guide groove component and a third alignment mark indicating a connection position of the optical element mounting component are aligned with the guide using photolithography technology. A part and the third alignment mark are aligned with each other to form the guide groove component, an optical element is mounted in accordance with the first alignment mark, and the third alignment mark is mounted on the second alignment mark. By aligning and connecting the guide groove component to the optical element mounting component by aligning the alignment marks, the optical element and the guide groove are aligned. Manufacturing method of optical module.