JPH10160975A - Optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate packaging and to manufacture an optical module at a low cost by pressing and installing an optical fiber block to a silicon substrate surface on which an optical element is mounted, then connecting and fixing an optical fiber block base and the silicon substrate surface. SOLUTION: The optical fiber block 6 installed with the optical fiber 8 in the guide groove 7 of the block base previously formed with the guide groove 7 is manufactured. The depth of the guide groove 7 is formed with the high accuracy in such a manner that the height of the optical fiber core from the fiber block base 61 is nearly equal to the height of the optical element 3 from the silicon substrate surface 11 when the optical fiber 8 is installed in the guide groove 7. The front end 81 of the optical fiber 8 is so installed as to project from the end face 62 of the optical fiber block. The optical fiber block formed in such a manner is so installed that the block base 61 and the surface 11 of the silicon substrate 1 come into contact with each other.

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 in the field of optical communications, and more particularly to a structure for easily mounting an optical module.

[0002]

2. Description of the Related Art Conventionally, an optical module mounting method includes positioning and fixing an optical fiber and a laser diode on a silicon mounting substrate as shown in FIG. Recently, a method of mounting using a mechanism called silicon passive alignment, which realizes integration of an optical fiber and a semiconductor laser on a silicon substrate by using a guide groove and a positioning reference surface formed on the silicon substrate, has been developed. ing. According to this configuration, since the guide groove can be formed with high accuracy by utilizing the good workability of the silicon substrate by the anisotropic etching, the alignment between the optical fiber and the optical element such as a semiconductor laser or a photodiode is complicated. It can be carried out without performing an appropriate alignment adjustment. In addition, since the silicon substrate has excellent thermal conductivity, there is an advantage that it is not necessary to use a heat sink for controlling the temperature of the laser diode.

[0003]

However, when an optical fiber is installed on a silicon substrate as described above, handling is not easy because the optical fiber is long, and the optical fiber is directly placed on the silicon substrate. There is a problem that the process of installing and fixing in the guide groove becomes complicated.
Further, even when the process of fixing the optical fiber into the guide groove is automated, it is not easy to manage the optical fiber.

An object of the present invention is to solve the above-mentioned problems in the conventional structure, and an object of the present invention is to provide an easy and practical means for mounting an optical module.

[0005]

In order to solve the above-mentioned conventional problems, a guide groove for installing an optical fiber, a rectangular groove for defining a position of a tip of the optical fiber, and an electrode portion for mounting an optical element are provided. In order to mount the optical fiber on the formed silicon substrate, an optical fiber block in which the optical fiber is installed and fixed in the guide groove of the fixed block in which the guide groove is formed on the bottom surface with high precision in advance is manufactured. After placing it in contact with the silicon substrate surface on which the element is mounted,
The bottom of the optical fiber block and the surface of the silicon substrate were connected and fixed. The height of the optical fiber core fixed in the guide groove on the bottom surface of the optical fiber block from the bottom surface of the optical fiber guide block is higher than the height of the light receiving / emitting surface of the optical element installed on the silicon substrate from the surface of the silicon substrate. The structure is such that the optical axis can be adjusted in the height direction of the optical fiber and the optical element only by installing the optical fiber block on the silicon substrate.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view showing one embodiment of an optical module mounting configuration according to the present invention. An electrode 2 for mounting an optical element is formed on a silicon substrate 1, and an optical element 3 is mounted thereon. A guide groove 5 for installing an optical fiber is formed up to the vicinity of the optical element 3. The guide groove is formed with high precision of less than micron by anisotropic etching. The depth of the guide groove is formed such that when the optical fiber is installed in the groove, the height of the core of the optical fiber is substantially equal to the height of the optical element mounted on the silicon substrate. At the end of the guide groove 5, a rectangular groove 4 is formed orthogonal to the guide groove longitudinal direction. In general, a rectangular groove is formed by machining such as dicing. The role of the rectangular groove 4 is to uniquely determine the distance between the optical fiber tip and the optical element 3 by abutting the tip of the optical fiber provided in the guide groove 5 on the rectangular groove 4. It is. As a method for optically coupling the optical fiber to the optical element 3 on the silicon substrate having the above structure, the optical fiber 8 is connected to the guide groove 5 of the silicon substrate 1.
It is realized by the following method without installing directly inside. The optical fiber block 6 in which the optical fiber 8 is installed in the guide groove 7 on the block bottom surface where the guide groove 7 is formed in advance is manufactured. As the material of the optical fiber block, ceramics such as quartz glass or silicon may be used. In terms of characteristics, a material whose linear expansion coefficient is as close as possible to that of the silicon substrate is preferable. If this condition is satisfied, a metal or resin material may be used. In this embodiment, the optical fiber is fixed in the guide groove by soldering. The depth of the guide groove 7 is
When the optical fiber core is set in the guide groove 7, the optical fiber core is formed with high precision so that the height of the optical fiber core from the fiber block bottom surface 61 is almost the same as the height of the optical element 3 from the silicon substrate surface 11. ing. Also, the optical fiber 8
Of the optical fiber block is protruded from the end face 62 of the optical fiber block. The optical fiber block 6 thus manufactured is placed so that the block bottom surface 61 and the surface 11 of the silicon substrate 1 are in contact with each other. At this time,
A part of the optical fiber 8 protrudes below the bottom surface 61 of the optical fiber block, but fits in the guide groove 5 on the silicon substrate 1, so that the optical fiber 8 of the fiber block 6 is in the guide groove 5 of the silicon substrate. The block bottom 61 and the silicon substrate surface 1
1 can be joined. Then, the height of the core center of the optical fiber 8 and the height of the optical element 3 on the silicon substrate can be uniquely matched. Further, by adjusting the position so that the optical fiber 8 of the fiber block fits into the guide groove 5 of the silicon substrate, the alignment in the optical axis horizontal direction can be automatically performed. This position adjustment can be easily realized because it is only necessary to make the fiber enter the guide groove 5. If the fiber block 6 is made of a transparent glass block so that it can be adjusted visually, position adjustment can be performed more easily. With the fiber block 6 in contact with the silicon substrate surface 11, the fiber block 6 is moved in the direction of the optical axis of the optical fiber. To end. Since the optical fiber tip 81 protrudes from the fiber block end face 62, fine adjustment of the fiber tip position in the optical axis direction by visual observation can be easily performed. The fiber block 6 is fixed on the silicon substrate surface 11 using an adhesive. The position adjustment and movement of the optical fiber in the optical axis horizontal direction and the optical axis direction can be performed by gripping the fiber block, which makes handling much easier than when directly gripping and moving the optical fiber. Was. FIG. 2 shows another embodiment of the present invention in which the fiber block 6 is fixed to the silicon substrate 1 by soldering. After forming a metal thin film of Cr / Au on the surface 11 of the silicon substrate 1, Au
A portion 91 where Sn solder is formed is formed, while a metal thin film of Cr / Au is similarly formed on the fiber block bottom surface 61 at a position where the metal thin film overlaps with the same pattern shape.
When such a pattern is formed in advance and soldered, highly reliable module mounting becomes possible. FIG. 3 shows another embodiment of the present invention in which the fiber block and the silicon substrate are aligned and fixed by markers 93 and 94 formed on the silicon substrate. In this case, a highly accurate guide groove 5 formed on the silicon substrate is not required. A slightly larger guide groove may be formed.

[0007]

According to the present invention, as described above in detail with reference to the embodiments, it is possible to manufacture an optical module more easily and at lower cost.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing one embodiment of a configuration of an optical module according to the present invention.

FIG. 3 is an overall perspective view showing another embodiment of the present invention.

FIG. 3 is an overall perspective view showing another embodiment of the present invention.

FIG. 4 is a top view showing a conventional example.

[Explanation of symbols]

 1, 11 silicon substrate 2 electrode 3 optical element 4 rectangular groove 5, 7 guide groove 6, 61, 62 fiber block 8, 81 light Fibers 91, 92, 93, 94: metal pattern, solder part

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[Procedure amendment]

[Submission date] February 10, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing one embodiment of a configuration of an optical module according to the present invention.

FIG. 2 is an overall perspective view showing a second embodiment of the present invention.

FIG. 3 is an overall perspective view showing a third embodiment of the present invention.

FIG. 4 is a top view showing a conventional example.

[Description of Signs] 1, 11 silicon substrate 2 electrode 3 optical element 4 rectangular groove 5, 7 guide groove 6, 61, 62 fiber block 8, 81 optical fiber 91, 92, 93, 94 metal pattern, solder part

Claims (3)

[Claims] An optical fiber is mounted on a silicon substrate on which a guide groove for installing an optical fiber, a rectangular groove for defining a position of a tip of the optical fiber, and an electrode portion for mounting an optical element are formed. In an optical module, an optical fiber block in which an optical fiber is previously installed and fixed in a guide groove formed on the block bottom with high precision is placed in contact with the surface of a silicon substrate on which an optical element is mounted, and then the optical fiber block bottom is An optical module, wherein the optical module is fixedly connected to the surface of the silicon substrate. 2. The height of the optical fiber core fixed in the guide groove on the bottom surface of the optical fiber block from the bottom surface of the optical fiber guide block is the surface of the light receiving / emitting surface of the optical element installed on the silicon substrate surface. 2. The optical module according to claim 1, wherein the height of the optical module is equal to the height of the optical module. 3. The optical module according to claim 1, wherein a tip of the optical fiber fixed to the optical fiber block projects from an end face of the block.