JP2002357731A - Chip for optical waveguide device, method for manufacturing the chip and optical waveguide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily position chips and to miniaturize the chips. SOLUTION: A pair of V-shaped grooves for aligning 37 are formed on a face of chips 31 and 32 and its opposite face on which at least either an optical waveguide or a V-shaped groove for fixing an optical waveguide or an optical fiber is formed and optically connected, guide pins 33 are arranged on V-shaped grooves 39 for fixing the guide pins formed on a base plate for fixing 34, V-shaped grooves for aligning 37 are engaged with the guide pins 33, thus chips 31 and 32 position each other. The chips are passively aligned and the V-shaped grooves necessary for the alignment and the guide pins are located on the back face side of the chips, thus the front face of the chips is not occupied by the V-shaped groves and the guide pins.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide device in which chips each having an optical waveguide formed thereon are connected to each other, and more particularly, to a device and a chip structure capable of simple alignment of the chips and a structure of the chip. It relates to a manufacturing method.

[0002]

2. Description of the Related Art An optical waveguide device capable of demultiplexing light by inserting a dielectric multilayer filter at the center of the Y-shape of a substantially Y-shaped optical waveguide is used in the field of optical communication and the like. It is used. FIG. 6 shows an example of a conventional configuration of such an optical waveguide device, which is separated into respective portions. In this example, two chips 11 and 12 are connected to each other to constitute an optical waveguide device. ing.

[0003] One optical waveguide 13 is formed on the surface of the first chip 11, and both ends of the optical waveguide 13 are exposed on both side surfaces of the chip 11, respectively. On the other hand, two optical waveguides 14 and 15 are formed on the surface of the second chip 12 so as to form a substantially V-shape.
The junction end and the branch end 15 are exposed on both side surfaces of the chip 12, respectively. In the figure, reference numerals 16 and 17 denote cladding layers, respectively. In this example, the dielectric multilayer filter 18 is provided by directly forming a film on the side of the chip 12 where the merging ends of the optical waveguides 14 and 15 are exposed, and the optical waveguides 14 and 15 are sandwiched by the dielectric multilayer filter 18. The optical waveguides 13, 14 and 15 are entirely Y
An optical waveguide device having a letter shape and having the dielectric multilayer filter 18 inserted therein is formed. Although not shown in the drawing, an optical fiber, for example, is connected to each of the other ends of the optical waveguides 13, 14, and 15.

In this optical waveguide device, as shown in FIG. 6, for example, when lights of different wavelengths λ ₁ and λ ₂ are inputted from the branch end of the optical waveguide 15, the light of wavelength λ ₁ is converted into a dielectric material. The optical waveguide 1 reflected by the body multilayer filter 18
The light having a wavelength of λ ₂ emitted from the branch end of No. 4 passes through the dielectric multilayer filter 18, enters the optical waveguide 13, and is emitted from the tip. By the way, in the optical waveguide device having the configuration as shown in FIG. 6, in the alignment (optical coupling) between the chips, the light emitted from one chip is received by the other chip, and the amount of received light is maximized. Active alignment is performed to find the position and connect the two, so that a light source is connected to one chip via an optical fiber, a power meter is connected to the other chip via an optical fiber, and the other chip is connected to the other chip. Is mounted on an X, Y, Z axis stage and moved.

Therefore, equipment such as a high-precision X, Y, Z-axis stage, a light source, and a power meter are required, and the positioning operation is complicated and extremely labor-intensive. On the other hand, FIG. 7 shows a conventional configuration example of an optical waveguide device configured so that chips can be easily aligned with each other only with mechanical accuracy, that is, passive alignment can be performed. Are given the same reference numerals. The illustration of the interface between the cladding layer and the chip substrate is omitted.

In this example, on the surfaces of the chips 11 and 12,
As shown in the figure, a pair of V grooves 21 are formed respectively, and a pair of guide pins 22
The guide pins 22 are engaged with the V-grooves 21
The chips 11 and 12 are aligned by aligning the V-grooves 21 of both chips 11 and 12. The V-groove 21 is required to have high dimensional accuracy and high positional accuracy. For example, such a V-groove 21 is made of single-crystal silicon for a chip substrate, and is anisotropically etched by using photolithography technology and etching technology. Can be formed.

[0007]

By adopting the structure shown in FIG. 7, the alignment between the chips can be performed very easily, but in this structure, a pair of guide pins with which the guide pins are engaged is used. An alignment V-groove is formed on the optical waveguide forming surface. In other words, in the conventional method of passively aligning chips by using the alignment V-groove and the guide pin, the V-groove is provided on the same surface as the surface on which the optical waveguide and other optical elements are arranged. Therefore, the size of the chip becomes large, and the miniaturization of the optical waveguide device is restricted.

[0008] Also, the position of the V-groove and the guide pin,
For example, formation of a V-groove for fixing an optical waveguide or an optical fiber, or a laser diode (LD) or a photodiode (PD)
However, the surface area of a chip that can be used for mounting such an optical element is limited. SUMMARY OF THE INVENTION In view of the above-described problems, it is an object of the present invention to easily align chips with each other by passive alignment, and to reduce the size of a chip and the size of an optical waveguide device as compared with the related art, or to reduce the size of an optical element. It is an object of the present invention to provide an optical waveguide device capable of increasing the surface area of a chip that can be used for the above, a structure of the chip, and a method of manufacturing the chip.

[0009]

According to the first aspect of the present invention, at least one of an optical waveguide and an optical fiber fixing V-groove is formed on one surface of a chip for an optical waveguide device, and a pair is formed on an opposite surface of the chip. Are formed. According to the invention of claim 2, the optical waveguide device has an optical waveguide or an optical fiber fixing V on one surface.
A pair of alignment V-grooves are respectively formed on the opposite surface of the plurality of chips at least one of which is formed and optically coupled to each other, and are formed on the fixing substrate at the same pitch as the pair of alignment V-grooves. The guide pins are respectively arranged in the pair of guide pin fixing V-grooves, and the pair of alignment V-grooves are engaged with the guide pins, and the plurality of chips are positioned with respect to each other.

According to a third aspect of the present invention, in the second aspect of the present invention, the pair of guide pin fixing V-grooves is bent at a predetermined angle at a middle portion thereof to form a polygonal line. One is formed with an optical fiber fixing V-groove, and is positioned at the above-mentioned predetermined angle with the other chip. According to the fourth aspect of the present invention, a pair of alignment V-grooves are formed on the opposite surface of the plurality of chips on which at least one of the optical waveguide and the optical fiber fixing V-groove is formed and optically coupled to each other. The chips in the optical waveguide device, each formed and having the alignment V-grooves engaged with the guide pins and the plurality of chips positioned relative to each other, are formed by arranging the plurality of chips adjacent to the same wafer. In this state, a pair of alignment V-grooves are collectively formed over the plurality of chips, and then cut out individually.

According to the fifth aspect of the present invention, at least one of an optical waveguide and an optical fiber fixing V-groove is formed on one surface and a pair of alignment chips are formed on a surface opposite to the one surface of a plurality of chips optically coupled to each other. The V-grooves are respectively formed, the V-grooves for alignment are engaged with the guide pins, and the plurality of chips are positioned with respect to each other. The chip in the optical waveguide device forms an alignment marker on the one surface, and has a double-sided aligner. It is manufactured by forming the alignment V-groove with reference to the alignment marker.

[0012]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a configuration of an embodiment of an optical waveguide device according to the present invention.
FIG. 2 is an exploded view of each part. First,
The configuration of each unit will be described with reference to FIG. In this example, the optical waveguide device includes two chips 31, 32 optically coupled to each other, a pair of guide pins 33, and a fixing substrate.

The chip 31 has an optical waveguide 13 formed on one half of one surface (front surface) 31a, similarly to the chip 11 shown in FIG. 6, and one end of the optical waveguide 13 is connected to the chip 31.
And the other end is exposed on the wall surface of a groove 35 formed substantially across the center of the chip 31. In this example, a V-groove 36 for fixing an optical fiber is formed in the other half of the surface 31 a of the chip 31. By mounting and fixing the optical fiber in the V-groove 36, the core becomes the end face of the optical waveguide 13. Is positioned and opposed. On the other hand, a pair of alignment V-grooves 37
Are formed over the entire length in parallel with the optical fiber fixing V-groove 36.

The chip 32 has a substantially V-shaped optical waveguide 1 on one half of its surface 32a, similarly to the chip 12 shown in FIG.
4 and 15 are formed, and these optical waveguides 14 and 15 are formed.
Is located on the side surface of the chip 12, and the branch end is exposed on the wall surface of a groove 38 formed substantially across the center of the chip 32. In the other half of the surface 32a of the chip 32, V-grooves 36 for fixing optical fibers are formed corresponding to the positions of the branch ends of the optical waveguides 14, 15, respectively. Also,
On the side surface of the chip 32 where the converging ends of the optical waveguides 14 and 15 are located, a dielectric multilayer filter 18 is formed by direct film formation. On the other hand, a pair of alignment V-grooves 37 is formed on the back surface 32 b of the chip 32, similarly to the chip 31.

The fixing substrate 34 has both the chips 31 and 32 mounted thereon via the guide pins 33. On the upper surface thereof, a pair of V-grooves 39 for fixing the guide pins is provided.
Are formed over the entire length at the same pitch as the V-groove 37 for alignment. The assembly of these parts is performed by inserting the guide pins 33 into the pair of guide pin fixing
The chips 31 and 32 are mounted by engaging a pair of alignment V-grooves 37 with the guide pins 33 and butted against each other, whereby the chips 31 and 32 are positioned with respect to each other. The optical waveguide device shown in FIG. 1 is configured.

In this manner, in this example, the chips can be aligned by passive alignment by engaging the alignment V-groove formed on the back surface of the chip with the guide pin. The alignment V-grooves formed on the back surfaces of both chips are required to have high precision with respect to the optical waveguides on the front surface, respectively. The alignment V-groove can be easily formed without requiring accuracy.

That is, chips to be connected to each other in an optical waveguide device are formed adjacent to each other on the same wafer, and alignment V-grooves are collectively formed over the chips in a wafer state, and then individually cut out. If the connection is made in the same manner as the arrangement at
The grooves need only be formed without positioning with respect to the optical waveguide on the front surface side, and the chips are inevitably aligned with high precision via the guide pins, that is, optically coupled with high precision. For example, single crystal silicon is used for the wafer substrate (chip substrate) in terms of forming an optical waveguide and forming a highly accurate V-groove for fixing an optical fiber, and the V-groove for fixing an optical fiber is formed by anisotropic etching. You. Note that glass or the like can be used.

The manufacture of the chip is not limited to the above-described method, and it can be manufactured individually. In this case, an alignment marker is formed on the surface of the chip with gold or the like with high precision with respect to the optical waveguide. Then, using a commercially available double-sided aligner provided with a means for irradiating infrared or X-rays passing through the chip substrate, its imaging means and image analysis means, an alignment V-groove is formed with reference to the alignment marker. In this way, the alignment V-groove can be formed on the rear surface of the optical waveguide on the front surface side with high precision. On the other hand, the pair of guide pin fixing V-grooves 39 formed in the fixing substrate 34 does not require high precision, and, for example, as shown in FIG. There may be.
That is, even if the pair of guide pins 33 is mounted as shown in FIG.
The two chips 31 and 32 are aligned with each other, so that the alignment accuracy is the guide pin fixing V-groove 39.
And the positioning accuracy is not impaired.

The fixing substrate having the V-groove can be manufactured using various materials and manufacturing methods for the above-described reasons. For example, it can be manufactured by molding a plastic, or V-grooves can be formed by etching using glass. Also, the V-groove can be formed by machining. In the example described above, two chips are aligned and optically coupled to each other, and both of the chips have an optical waveguide and an optical fiber fixing V-groove as optical elements. The present invention is not limited to this. For example, the chip may include an optical waveguide and an optical element such as a laser diode or a photodiode as an optical element. Further, a chip having an optical waveguide may be interposed between the two chips, and the three chips may be connected. The dielectric multilayer filter can be disposed by, for example, bonding or sandwiching, in addition to forming the film directly as described above.

FIG. 4 shows another example of the configuration of the optical waveguide device according to the present invention. In this example, a chip 41 is connected to the chip 32 described above. The chip 41 has an optical fiber fixing V-groove 36 formed on the front surface 41a and a pair of alignment V-grooves 37 formed on the back surface 41b. In this example, a pair of guide pin fixing V-grooves 39 are formed in the fixing substrate 34 so as to be bent at a predetermined angle at a middle portion thereof to form a broken line as shown in the figure. The pair of guide pin fixing V-grooves 39 having such a shape are each provided with a guide pin 3 at each linear portion.
3 and 33 'are disposed, and these guide pins 33, 3
3 'aligns chips 32 and 41 at a predetermined angle. FIG. 5A shows this state. FIG. 5B shows a state in which the optical fibers 42 are mounted and fixed in the respective optical fiber fixing V-grooves 36.

In this example, the light mounted on the chip 41 at a predetermined angle from the side surface of the chip 32 facing the chip 41, that is, in the direction of the light to be emitted obliquely, not perpendicular to the end face of the optical waveguide. When the fiber 42 is aligned and the chips need to be aligned with each other at a predetermined angle rather than on a straight line and optically coupled, if the configuration shown in this example is adopted, Can be connected very easily. The fixing substrate 34 having the guide pin fixing V-grooves 39 can be formed by, for example, plastic molding, as described above.
However, it can be easily formed.

[0022]

As described above, according to the optical waveguide device of the present invention, chips to be coupled can be easily positioned by passive alignment. Further, since the alignment V-groove used for alignment and the guide pin engaged therewith are not located on the front surface side of the chip where the optical waveguide and other optical elements are arranged as in the related art, but on the rear surface side of the chip, The chip surface area can be reduced to reduce the size of the chip and the size of the device, or the surface area of the chip that can be used for the optical element can be increased.

Further, according to the third aspect of the invention, it is possible to easily connect the chips at a predetermined angle. According to the invention of claim 4, the alignment V-groove on the back surface of the chip can be easily formed without the need for positioning with respect to the optical element on the front surface of the chip, and highly accurate alignment between chips can be realized. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the invention of claim 2;

FIG. 2 is an exploded perspective view of FIG.

FIG. 3 is a view for explaining an assembling state when there is a difference in groove width between left and right guide pin fixing V grooves in FIG. 1;

FIG. 4 is an exploded perspective view for explaining one embodiment of the invention of claim 3;

5A is a perspective view showing an assembled state of the components shown in FIG. 4, and FIG. 5B is a perspective view showing a state in which an optical fiber is mounted on A.

FIG. 6 is a diagram illustrating an example of a conventional configuration of an optical waveguide device and alignment of chips thereof.

FIG. 7 is a view for explaining another example of the conventional configuration of the optical waveguide device and the positioning of chips thereof.

Claims (5)

[Claims] 1. An optical waveguide device, wherein at least one of an optical waveguide and an optical fiber fixing V-groove is formed on one surface, and a pair of alignment V-grooves are formed on a surface opposite to the one surface. Chips. 2. A pair of alignment V-grooves are respectively formed on a surface opposite to the one surface of a plurality of chips which are formed with at least one of an optical waveguide and an optical fiber fixing V-groove on one surface and optically coupled to each other; Guide pins are respectively arranged in a pair of guide pin fixing V-grooves formed on the fixing substrate at the same pitch as the pair of alignment V-grooves, and the pair of alignment V-grooves are engaged with the guide pins. An optical waveguide device, wherein the plurality of chips are positioned with respect to each other. 3. The optical waveguide device according to claim 2, wherein an intermediate portion of the pair of guide pin fixing V-grooves is bent at a predetermined angle to form a polygonal line. An optical waveguide device is characterized in that one of the optical waveguide devices has an optical fiber fixing V-groove formed therein and is positioned at the predetermined angle with respect to another chip. 4. A plurality of chips each having at least one of an optical waveguide and an optical fiber fixing V-groove formed on one surface thereof and a pair of alignment V-grooves formed on opposite surfaces of the plurality of chips optically coupled to each other, A method of manufacturing said chip in an optical waveguide device in which said alignment V-groove is engaged with a guide pin and said plurality of chips are positioned with respect to each other. A method of manufacturing a chip for an optical waveguide device, comprising: forming a pair of alignment V-grooves over a plurality of chips in a wafer state and cutting them out individually. 5. A pair of alignment V-grooves are respectively formed on one surface of at least one of an optical waveguide and an optical fiber fixing V-groove, and on a surface opposite to the one surface of the plurality of chips optically coupled to each other, A method of manufacturing the chip in an optical waveguide device in which the alignment V-groove is engaged with a guide pin and the plurality of chips are positioned with respect to each other, wherein an alignment marker is formed on one surface, and a double-sided aligner is used. Forming the alignment V-groove with reference to the alignment marker.