Fitting body and method for manufacturing optical module

Abstract

To provide a fitting body capable of positioning an optical element with high accuracy.SOLUTION: A fitting body according to one aspect of the present invention is a fitting body included in an optical module, the fitting body including a substrate having a first optical waveguide, an optical element having a second optical waveguide, and a guide member stacked on the substrate, the optical element and the guide member being configured to be fittable to each other such that the first optical waveguide and the second optical waveguide are optically coupled to each other, the optical element is configured to be fitted to the guide member, thereby being capable of suppressing rotation with respect to an axis in a lamination direction of the guide member, and the guide member is configured to be capable of suppressing displacement in a direction orthogonal to a coupling axis at which the first optical waveguide and the second optical waveguide are optically coupled to each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a mating body and an optical module. [Background technology]

[0002] In information processing devices and devices used in data communications, optical signals are transmitted and received by optical modules having optical waveguides that couple to optical fibers. From the viewpoint of coupling between the optical waveguide and the optical fiber, optical modules are required to more easily and efficiently align the coupling between the optical waveguide and the optical fiber.

[0003] Patent Document 1 discloses a technique relating to an optical waveguide device in which an optical fiber is fixed in a groove provided in a chip, and Patent Document 2 discloses a technique relating to an optical fiber connection method in which an optical fiber is connected to an optical waveguide while guiding the optical fiber along a groove provided near the optical waveguide. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-357731 [Patent Document 2] Japanese Patent Application Publication No. 7-63947 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to improve the light receiving efficiency of light propagated through an optical fiber, the positioning of the optical elements included in the optical module is important. The positioning of the optical elements using grooves as described in Patent Documents 1 and 2 did not provide sufficient positioning accuracy for the optical elements.

[0006] An object of the present invention is to provide a fitting body that allows for highly accurate positioning of an optical element. [Means for solving the problem]

[0007] A mating body according to one aspect of the present invention is a mating body included in an optical module, and includes a substrate having a first optical waveguide, an optical element having a second optical waveguide, and a guide member stacked on the substrate, wherein the optical element and the guide member are configured to be matable with each other so that the first optical waveguide and the second optical waveguide are optically coupled to each other, the optical element is configured to be matable with the guide member so that rotation about an axis in the stacking direction of the guide member can be suppressed, and the guide member is configured to be able to suppress positional deviation in a direction perpendicular to the coupling axis along which the first optical waveguide and the second optical waveguide are optically coupled. [Effects of the Invention]

[0008] According to the fitting body of the present invention, it is possible to position the optical element with high precision. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing the overall configuration of an optical module including a mating body according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view of the fitting body shown in FIG. 1 taken along line II-II. [Figure 3] 10A to 10C are diagrams illustrating a method for manufacturing an optical module including a mating body according to an embodiment of the present invention. [Figure 4] 10A and 10B are schematic diagrams illustrating modified examples of the configuration of the fitting body according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail. To facilitate understanding of the description, the same components in the drawings will be designated by the same reference numerals, and duplicate descriptions will be omitted as appropriate. Furthermore, the scale of each component in the drawings may differ from the actual scale.

[0011] In the drawings, directions are indicated by the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are mutually perpendicular directions. The direction in which the arrow points in the X-axis direction is referred to as the +X direction or +X side, and the direction opposite to the +X direction is referred to as the -X direction or -X side. The direction in which the arrow points in the Y-axis direction is referred to as the +Y direction or +Y side, and the direction opposite to the +Y direction is referred to as the -Y direction or -Y side. The direction in which the arrow points in the Z-axis direction is referred to as the +Z direction or +Z side, and the direction opposite to the +Z direction is referred to as the -Z direction or -Z side.

[0012] [Embodiment] <Optical module configuration> First, the configuration of an optical module 1 including a mating body 100 according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing the overall configuration of an optical module 1 including a mating body 100 according to one embodiment of the present invention. Figure 2 is a cross-sectional view of the mating body 100 shown in Figure 1 taken along line II-II. In Figure 1, L indicates a coupling portion between a first optical waveguide 10a and a second optical waveguide 20a, which will be described later.

[0013] In the following description, for each component, the bond axis direction described later is defined as the X direction, the direction perpendicular to the bond axis is defined as the Y direction, and the direction in which the guide members 30 are stacked is defined as the Z direction.

[0014] The optical module 1 includes a substrate 10, an optical element 20, and a guide member 30. The optical module 1 is coupled to, for example, an optical fiber. When coupling the optical module 1 to the optical fiber, for example, an optically transparent adhesive, an index matching fluid, or the like can be used, but is not limited to these.

[0015] The substrate 10 has a first optical waveguide 10a. The substrate 10 is preferably made of a material with a low dielectric constant, such as at least one material selected from the group consisting of single crystal silicon (Si), AlN, Al2O3, Cu, GaAs, GaN, GaP, InP, Si, SiC, and SiO2, which includes a material having a crystalline or amorphous structure.

[0016] The substrate 10 may be made of polyimide resin, epoxy resin, phenolic resin, polyphenylene ether resin, fluororesin, cycloolefin polymer, liquid crystal polymer, quartz, ceramics, glass epoxy in which glass fiber is impregnated with epoxy resin, glass composite in which glass cloth and nonwoven glass cloth are impregnated with epoxy resin, paper epoxy in which paper is impregnated with epoxy resin, paper phenol in which paper is impregnated with phenolic resin, LTCC in which alumina and glass are impregnated, HTCC in which alumina and aluminum nitride are impregnated, composite materials in which ceramics and various resins are combined, etc. In particular, the technology for densely integrating a large number of optical elements on a silicon substrate (SOI: Silicon On Insulator) is called Si photonics.

[0017] The length of the first optical waveguide 10a of the substrate 10 varies depending on the configuration of the optical circuit, but the width is 10 nm to 10 μm, preferably 100 nm to 1 μm, and more preferably 400 nm to 600 nm. In this embodiment, the width of the first optical waveguide 10a of the substrate 10 is 400 μm.

[0018] The first optical waveguide 10a of the substrate 10 is made of a semiconductor containing silicon, SiO2, various resin materials, or the like, and is formed by, for example, photolithography, photobleaching, direct exposure, stamping, or the like.

[0019] In particular, optical waveguides in Si photonics are often formed with a Si core and SiO2 cladding. The core is the part that transmits light and has a high refractive index. The cladding is the part that physically protects the core and has a lower refractive index than the core. The large difference in refractive index between the Si core and the SiO2 cladding allows for total reflection of light, enabling strong light confinement. This makes it possible in Si photonics to form optical waveguides that are bent over a small area, allowing for significant miniaturization of optical circuits. As a result, Si photonics can realize high-density optical integrated circuits.

[0020] The optical element 20 has a second optical waveguide 20a, side surfaces 21 and 22, and a convex portion 23. When viewed from the direction in which the guide member 30 is stacked (Z direction), the line connecting the end portions 21a and 22a of the side surfaces 21 and 22 of the optical element 20 on the convex portion 23 side to the tip 23a of the convex portion 23 is a straight line.

[0021] The optical element 20 may be a light-receiving element such as a photodiode, or may be a light-emitting element such as a laser element, a modulation element, or a branching element. The optical element 20 has a second optical waveguide 20a. The optical element 20 is made of single crystal Si, gallium arsenide (GaAs), germanium (Ge), or a III-V group compound such as InP, InGaAs, InGaAsP, or InAlAs. In this embodiment, the optical element 20 will be described as a light-receiving element.

[0022] The second optical waveguide 20a of the optical element 20 has a length that varies depending on the configuration of the optical circuit, but has a width of 10 nm to 1 μm, preferably 20 nm to 300 nm, and more preferably 30 nm to 100 nm. The length of the second optical waveguide 20a is 10 μm to 5 mm, preferably 20 μm to 3 mm, and more preferably 30 μm to 1 mm. In this embodiment, the second optical waveguide 20a of the optical element 20 has a length of 20 μm and a width of 2 μm.

[0023] The second optical waveguide 20a of the optical element 20 is made of a semiconductor containing silicon, SiO2, various resin materials, etc., and is formed by photolithography, photobleaching, direct exposure, stamping, etc., similar to the first optical waveguide 10a of the substrate 10.

[0024] In order to propagate light from the first optical waveguide 10a of the substrate 10 to the second optical waveguide 20a of the optical element 20, it is necessary for the first optical waveguide 10a and the second optical waveguide 20a to overlap. Therefore, the first optical waveguide 10a and the second optical waveguide 20a are overlapped at a coupling portion L. The length of the coupling portion L is preferably 5 to 10 μm or more. In the following, the axis along which the first optical waveguide 10a and the second optical waveguide 20a are optically coupled at the coupling portion L is referred to as the coupling axis.

[0025] The guide member 30 is laminated on the substrate 10 of the optical module 1, covering the surface 11 of the substrate 10. The guide member 30 is laminated on the substrate 10. The optical element 20 and the guide member 30 are configured to be engageable with each other so that the first optical waveguide 10a and the second optical waveguide 20a are optically coupled to each other.

[0026] The guide member has a recess 31. The guide member 30 has a shape that forms a pair with the optical element 20, and the protrusion 23 of the optical element 20 is fitted into the recess 31 of the guide member to form a fitted body 100. By fitting the optical element 20 into the guide member 30, the optical element 20 is configured to be able to suppress rotation about an axis in the stacking direction (Z direction) of the guide member 30. Furthermore, the guide member 30 is configured to be able to suppress positional deviation in a direction (XY plane) perpendicular to the coupling axis along which the first optical waveguide 10a and the second optical waveguide 20a are optically coupled.

[0027] When the first optical waveguide 10a of the substrate 10 and the second optical waveguide 20a of the optical element 20 are optically coupled, the more overlapping the two optical waveguides are, the easier it is for light to propagate, and an overlap of at least 5 μm in the coupling axis direction is required. The smaller the misalignment in the width direction of the optical waveguide, the better, and a misalignment of 0.2 μm or less is preferable. In this embodiment, when the first optical waveguide 10a of the substrate 10 and the second optical waveguide 20a of the optical element 20 are optically coupled, no misalignment occurs in the direction in which the guide member 30 is stacked (Z direction).

[0028] The guide member 30 is preferably formed from a photoresist material consisting of a novolac resin and a 1,2-naphthoquinone diazide sulfonic acid ester (commonly known as NQD) compound. The photoresist material allows for precise contouring, and a photoresist material containing novolac resin is particularly suitable for processing with submicron accuracy. After the guide member 30 is placed on the substrate 10 and mated with the optical element 20, the guide member 30 can be removed using a developer, primarily an alkaline aqueous solution. If the guide member 30 is to remain, positive-type photosensitive polyimide resin or negative-type photosensitive polyimide resin can be used. Using a photosensitive resin for the guide member 30 simplifies the manufacturing process of the optical module 1, as it allows for precise contouring and eliminates the need to cut the substrate 10.

[0029] Here, in terms of optical loss, in the optical coupling between the first optical waveguide 10a of the substrate 10 and the second optical waveguide 20a of the optical element 20, the influence of the misalignment in the direction perpendicular to the coupling axis is greater than the influence of the misalignment in the coupling axis direction.

[0030] Even if the size of guide member 30 in relation to optical element 20 differs slightly from the design value during manufacturing of optical module 1, mating body 100 can suppress misalignment at least in the direction perpendicular to the coupling axis. Therefore, optical module 1 using mating body 100 makes it easier to suppress optical loss.

[0031] <Optical module manufacturing method> The following describes an example of a method for manufacturing the optical module 1. Figure 3 is a diagram for explaining a method for manufacturing the optical module 1 including the mating body 100 according to one embodiment of the present invention. The optical module 1 is manufactured in the order of (a), (b), and (c) in Figure 3.

[0032] As shown in Fig. 3(a), first, a substrate 10 is formed as a flat plate made of, for example, single crystal Si. Next, as shown in Fig. 3(b), a guide member 30 is laminated on a surface 11 of the substrate 10. The laminated guide member 30 is processed into a shape that pairs with the optical element 20 using, for example, photolithography technology.

[0033] 3(c), the optical element 20 is fitted into the guide member 30. The formed fitted body 100 is fixed by applying pressure and heat in the fitted state. Prior to fixing, the optical element 20 and the guide member 30 may be temporarily bonded.

[0034] A laser beam or the like may be used to fix the fitting body 100. When exposing the fitting body 100, it is preferable that the accuracy of the exposure position is less than 0.1 μm. A stepper or the like is used as the exposure device. It is preferable that the guide member 30 is removed after the optical element 20 is fixed, but it may be left in place.

[0035] <Modification> 4 is a schematic diagram showing a modified example of the configuration of the fitted body 100 according to one embodiment of the present invention. The illustrated example is a view of the fitted body 100 as seen from the Z direction, and configurations other than the optical element 20 and guide member 30 that make up the fitted body 100 are omitted from the illustration.

[0036] 4(a), the optical element 20 has a recess 24, and the guide member 30 has a protrusion 32. The recess 24 of the optical element 20 and the protrusion 32 of the guide member 30 are fitted together. When viewed from the Z direction, the line connecting the end portions 21b and 22b on the recess 24 side of each of the side surfaces 21 and 22 of the optical element 20 to the tip 24a of the recess 24 is a straight line.

[0037] 4(b) is an example of a modified example of the fitting body 100 in which the optical element 20 has a protrusion 25. The guide member 30 fits into the optical element 20 at the protrusion 25. In the example shown, a gap is formed between the optical element 20 and the guide member 30, but a structure without a gap is also possible. The protrusion 25 may include a second optical waveguide 20a.

[0038] The modified example of the fitting body 100 shown in FIG. 4(c) is an example having a plurality of fitting portions where the optical element 20 and the guide member 30 are fitted together. In the example shown, the fitting body 100 has three fitting portions. Three guide members 30 are provided, but the number is not limited to three. Each guide member 30 may be cylindrical or conical. In the example shown, the optical element 20 can be fixed by fitting the optical element 20 and the guide member 30 together while miniaturizing the guide member 30.

[0039] A modified example of the mating body 100 shown in FIG. 4(d) is one in which a plurality of mating bodies 100 shown in FIG. 1 are arranged in the Y direction. Furthermore, the four guide members 30 may be combined into one. In this case, the mating body 100 has a plurality of mating portions into which the optical elements 20 can be fitted, relative to one guide member 30. In the illustrated example, the mating body 100 has four mating portions. Note that in the illustrated example, four pairs of mating bodies 100 are arranged, but this is not limited to four pairs. Furthermore, the structure of the illustrated plurality of mating bodies 100 is not limited to the structure shown in FIG. 1, and may be the structures shown in FIGS. 4(a) to 4(c).

[0040] <Effects> The fitting body 100 can suppress not only misalignment in the direction perpendicular to the coupling axis (Y direction) but also rotation about the axis in the stacking direction (Z direction) of the guide member 30, that is, rotation within the XY plane, with respect to the optical element 20. Therefore, the fitting body 100 according to this embodiment can improve the positioning accuracy of the optical element 20.

[0041] Furthermore, because the guide member 30 is laminated on the substrate 10, it is easy to process and can ensure positioning accuracy in accordance with changes in the outer shape and dimensions of the optical element 20. Therefore, even if the optical module 1 is miniaturized, it is possible to improve the positioning accuracy of the optical element 20.

[0042] Furthermore, in the fitting body 100 according to this embodiment, the optical element 20 is fitted into the guide member 30 from the coupling axis direction (X direction), which makes it easy to mount the optical element 20 on the substrate 10 and allows for high integration of the optical element 20 on the substrate 10.

[0043] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as set forth in the claims.

[0044] The embodiments of the present invention are as follows, for example. <1> A mating body included in an optical module, a substrate having a first optical waveguide; an optical element having a second optical waveguide; a guide member laminated on the substrate; Equipped with the optical element and the guide member are configured to be engageable with each other so that the first optical waveguide and the second optical waveguide are optically coupled to each other; the optical element is configured to be able to be prevented from rotating about an axis in a stacking direction of the guide member by fitting with the guide member, the guide member is configured to be able to suppress positional deviation in a direction perpendicular to a coupling axis along which the first optical waveguide and the second optical waveguide are coupled. Interlocking body. <2> the optical element has a convex portion, The guide member has a recess, The protrusion and the recess are engageable with each other. The aforementioned <1> The fitting body according to claim 1. <3> the optical element has a recess; The guide member has a protrusion, The recess and the protrusion can be fitted together. The aforementioned <1> The fitting body according to claim 1. <4> The optical element has a plurality of fitting portions into which the guide member is fitted. The aforementioned <1> The fitting body according to claim 1. <5> One of the guide members has a plurality of fitting portions where the optical element and the guide member are fitted together. The aforementioned <1> From the above <4> 10. The fitting body according to claim 9, wherein the fitting body is a fitting body having a first end and a second end. <6> The guide member is made of a photosensitive resin. The aforementioned <1> From the above <5> 10. The fitting body according to claim 9, wherein the fitting body is a fitting body having a first end and a second end. <7> A method for manufacturing an optical module including an optical element having a first optical waveguide and a guide member, comprising: disposing the guide member on a substrate having a second optical waveguide; and fitting the optical element and the guide member together so that the first optical waveguide and the second optical waveguide are coupled to each other, the optical element is configured to be able to be prevented from rotating about an axis in a stacking direction of the guide member by fitting with the guide member, the guide member is configured to be able to suppress positional deviation in a direction perpendicular to a coupling axis along which the first optical waveguide and the second optical waveguide are coupled. Optical module manufacturing method. [Explanation of symbols]

[0045] 1 Optical Module 10 Substrate 10a 1st optical waveguide 20 Optical elements 20a 2nd optical waveguide 23 Convex part 24 recess 25 Protrusion 30 Guide member 31 Recess 32 Convex part 100 mating body

Claims

1. A mating body included in an optical module, a substrate having a first optical waveguide; an optical element having a second optical waveguide; a guide member laminated on the substrate; Equipped with the optical element and the guide member are configured to be engageable with each other so that the first optical waveguide and the second optical waveguide are optically coupled to each other; the optical element is configured to be able to be prevented from rotating about an axis in a stacking direction of the guide member by fitting with the guide member, the guide member is configured to be able to suppress positional deviation in a direction perpendicular to a coupling axis along which the first optical waveguide and the second optical waveguide are optically coupled. Interlocking body.

2. the optical element has a convex portion, The guide member has a recess, The protrusion and the recess are engageable with each other. The fitting according to claim 1 .

3. the optical element has a recess; The guide member has a protrusion, The recess and the protrusion can be fitted together. The fitting according to claim 1 .

4. The optical element has a plurality of fitting portions into which the guide member is fitted. The fitting according to claim 1 .

5. One of the guide members has a plurality of fitting portions where the optical element and the guide member are fitted together. The fitting according to claim 1 .

6. The guide member is made of a photosensitive resin. The fitting according to claim 1 .

7. A method for manufacturing an optical module including an optical element having a first optical waveguide and a guide member, the method comprising: disposing the guide member on a substrate having a second optical waveguide; and fitting the optical element and the guide member together so that the first optical waveguide and the second optical waveguide are optically coupled to each other, the optical element is configured to be able to be prevented from rotating about an axis in a stacking direction of the guide member by fitting with the guide member, the guide member is configured to be able to suppress positional deviation in a direction perpendicular to a coupling axis along which the first optical waveguide and the second optical waveguide are optically coupled. Optical module manufacturing method.

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