JP2006349861A - Optical waveguide, optical module, and manufacturing method of optical waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress deformation of a sheet-like optical waveguide. <P>SOLUTION: In the optical waveguide 1A, a supporting substrate 3A is mounted on the surface of a planar waveguide sheet 2A having a core 4 and a clad layer 5. The supporting substrate 3A is extended in the array direction of the core 4 and attached to both ends of the waveguide sheet 2A. The waveguide sheet 2A, forming the core 4 in a prescribed pattern, is prepared on a wafer substrate and, with the supporting substrate 3A attached thereto, is separated from the wafer substrate, so that the optical waveguide 1A is manufactured. Consequently, during the separation from the wafer substrate, the deformation of the waveguide sheet 2A is suppressed with the supporting substrate 3A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet-like optical waveguide having a core / cladding structure, an optical module including the optical waveguide, and a method of manufacturing the optical waveguide. Specifically, the deformation of the waveguide sheet can be suppressed by attaching a support substrate to the surface of the waveguide sheet.

  Conventionally, information transmission between boards in electronic devices, between chips, etc. has been performed by electrical signals, but optical wiring technology has attracted attention in order to realize ultra high speed, large capacity information transmission, A waveguide-type optical module has been proposed that can transmit an optical signal using a planar optical waveguide.

  As an optical waveguide for realizing such an optical module, there has been proposed a technique for suppressing the pitch shift of the waveguide array after mounting by controlling the linear expansion coefficient of the side plate bonded and mounted to the optical waveguide ( For example, see Patent Document 1).

Japanese Patent Laid-Open No. 04-45654

  As a technique for producing a planar optical waveguide, a technique has been proposed in which an optical waveguide is produced on a wafer substrate using a polymer material or the like, and then the wafer substrate is peeled off to produce a sheet-like optical waveguide. Yes.

  However, when an optical waveguide is produced by such a manufacturing process, stress on the wafer substrate is inherent due to heat treatment and curing conditions during production. As a result, when the optical waveguide is peeled from the wafer substrate, there is a problem that deformation such as expansion, contraction, warpage, etc. of the optical waveguide occurs due to relaxation of the internal stress.

  And even if the deformed optical waveguide is mounted on a plate material or the like, it is not possible to compensate for a shift in the core pitch or the like. In addition, when an optical waveguide is manufactured by predicting a change amount of the core pitch and making corrections in advance, the correction amount changes depending on environmental conditions such as temperature and humidity, and thus cannot be accurately controlled. is there.

  The present invention has been made to solve such a problem, and an object thereof is to provide an optical waveguide capable of suppressing deformation, an optical module provided with the optical waveguide, and a method of manufacturing the optical waveguide. .

  In order to solve the above-described problems, an optical waveguide according to the present invention includes a waveguide sheet having at least one core and a clad, and a support substrate that holds the shape of the waveguide sheet and is attached to the surface of the waveguide sheet. It is characterized by comprising.

  In the optical waveguide of the present invention, the stress applied to the waveguide sheet is received by the support substrate, and deformations such as expansion, contraction, and warpage of the waveguide sheet are suppressed.

  An optical module according to the present invention includes the above-described optical waveguide, and a support substrate that holds the shape of the waveguide sheet is attached to the surface of the waveguide sheet having at least one core and a clad. An optical waveguide and any one of an optical element and an optical transmission path optically coupled to the core, or both an optical element and an optical transmission path are provided.

  In the optical module of the present invention, if the core of the optical waveguide and the optical element are coupled, and the optical element is a light emitting element, the light emitted from the optical element enters the core and propagates through the core. If the optical element is a light receiving element, the light propagated through the core enters the light receiving element.

  Furthermore, if the core of the optical waveguide and the optical transmission path are combined, the light propagated through the core enters the optical transmission path, propagates through the optical transmission path, and the light propagated through the optical transmission path It enters the core and propagates through the core.

  The optical waveguide coupled to the optical element and the optical transmission path receives stress applied to the waveguide sheet by the support substrate, and the deformation, such as expansion, contraction, and warpage of the waveguide sheet is suppressed. Are accurately aligned.

  In the method for manufacturing an optical waveguide according to the present invention, a waveguide sheet having at least one core and a cladding is formed on a wafer substrate, and a support substrate is attached to the surface of the waveguide sheet formed on the wafer substrate. The waveguide sheet to which the support substrate is attached is peeled off from the wafer substrate to produce an optical waveguide in which the shape of the waveguide sheet is held by the support substrate.

  In the optical waveguide manufacturing method of the present invention, the stress applied to the waveguide sheet by peeling the waveguide sheet from the wafer substrate after the support substrate is attached to the surface of the waveguide sheet formed on the wafer substrate. Is received by the support substrate, and deformations such as expansion, contraction, and warping of the waveguide sheet after peeling from the wafer substrate are suppressed.

  According to the optical waveguide of the present invention, since the support substrate is attached to the surface of the waveguide sheet, the waveguide sheet can be prevented from being deformed, such as expansion, contraction, warpage, and the accuracy of the position where the core is formed is improved. Can be improved. In an optical module having such an optical waveguide, the optical waveguide can be accurately aligned with the optical element and the optical transmission path, so that low-loss optical coupling characteristics can be realized.

  Further, according to the method for manufacturing an optical waveguide of the present invention, after attaching the support substrate to the waveguide sheet formed on the wafer substrate, the waveguide sheet is peeled off from the wafer substrate, so that after the peeling from the wafer substrate. Deformation of the waveguide sheet is suppressed. As a result, by using a semiconductor manufacturing process or the like, misalignment of the core formed with high accuracy on the wafer substrate is suppressed, and high accuracy of the core can be realized.

  Hereinafter, an optical waveguide, an optical module, and a method for manufacturing an optical waveguide according to the present invention will be described with reference to the drawings.

<Configuration Example of Optical Waveguide of First Embodiment>
1A and 1B are configuration diagrams showing an example of an optical waveguide according to the first embodiment. FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line AA in FIG.

  The optical waveguide 1A of the first embodiment includes a waveguide sheet 2A having a core / cladding structure, and a support substrate 3A that holds the shape of the waveguide sheet 2A.

  The waveguide sheet 2 </ b> A is made of, for example, a polymer material, and includes one or a plurality of cores 4 that extend linearly and a cladding layer 5 that covers the cores 4. In this example, the waveguide sheet 2A has a plurality of cores 4 arranged in parallel at a predetermined pitch on the lower clad 5a constituting the clad layer 5, and the core 4 on the lower clad 5a The embedded waveguide is covered with the upper clad 5b, and the thickness of the waveguide sheet 2A is about 100 μm.

  The waveguide sheet 2A is configured such that the refractive index of the core 4 is slightly larger than the refractive indexes of the lower cladding 5a and the upper cladding 5b, and the light coupled to the core 4 is confined in the core 4 and propagated. .

  The waveguide sheet 2 </ b> A has a quadrangular shape and faces the extending direction of the core 4, inclined end faces 6 are formed on two sides where each core 4 intersects, and faces the core 4 alignment direction. Vertical end surfaces 8 are formed on two substantially parallel sides.

  The inclined end surface 6 is an inclined surface having an inclination of approximately 45 degrees with respect to the surface of the waveguide sheet 2A, and the reflecting surface 7 is formed by exposing the end surface of the core 4. The reflecting surface 7 is formed by exposing the end surface of the core 4 to the same surface as the inclined end surface 6, and has an inclination of approximately 45 degrees with respect to the extending direction of the core 4. As a result, the light incident substantially perpendicular to the surface of the waveguide sheet 2A is reflected by the reflecting surface 7 and coupled to the core 4, and the light propagated through the core 4 is reflected by the reflecting surface 7 and guided. The light is emitted substantially perpendicular to the surface of the waveguide sheet 2A.

  The support substrate 3A is bonded and fixed to the surface of the waveguide sheet 2A. The support substrate 3A is made of, for example, a single material of silicon (Si), glass, resin, or a mixed material thereof, and has a thickness capable of maintaining the shape of the waveguide sheet 2A. Here, when the support substrate 3A is made of silicon or glass, the thickness of the support substrate 3A is set to about 0.5 to 1 mm as an example.

  The support substrate 3A has, for example, the same length as the width of the waveguide sheet 2A along the alignment direction of the cores 4 so that the pitch between the cores 4 can be maintained, and extends in the alignment direction of the cores 4 Is attached to the waveguide sheet 2A.

  In this example, two support substrates 3A are attached to the waveguide sheet 2A, and the attachment positions of the support substrates 3A are set at both ends of the waveguide sheet 2A in the length direction along the extending direction of the core 4. The The support substrate 3A is preferably attached to the waveguide sheet 2A adjacent to the upper end of the inclined end surface 6.

  However, in the optical waveguide manufacturing process described later, the support substrate 3A is attached slightly inside the inclined end surface 6 so that the inclined end surface 6 can be formed by dicing the waveguide sheet 2A without dicing the support substrate 3A. A cutting relief 9 is formed between the support substrate 3 </ b> A and the inclined end surface 6. Here, the length of the cutting relief portion 9 is preferably 5 mm or less, for example, so that the shape of the end portion of the waveguide sheet 2A can be held by the support substrate 3A.

<Example of Manufacturing Process of Optical Waveguide of First Embodiment>
FIG. 2 is a process diagram showing a manufacturing process of the waveguide sheet 2A, FIG. 3 is a plan view showing an example of the produced waveguide sheet 2A, FIG. 4 is a plan view showing an attaching process of the support substrate 3A, and FIG. The plan view showing the dicing process of the waveguide sheet 2A. Next, the manufacturing process of the optical waveguide 1A of the first embodiment will be described as an example of the first embodiment of the manufacturing method of the optical waveguide.

  First, as shown in FIG. 2A, a lower clad forming thin film 52a is applied to a predetermined film thickness on a wafer substrate 51 by using, for example, a photosensitive polymer material constituting the lower clad 5a. In this example, as the polymer material constituting the core 4 and the lower clad 5a and the upper clad 5b, an acrylic, epoxy, polyimide, polysilane, or other ultraviolet curable polymer material is used.

  Next, the lower clad forming thin film 52 a is cured by irradiating with ultraviolet rays UV, and the lower clad 5 a is produced on the wafer substrate 51.

  Next, as shown in FIG. 2B, a core-forming thin film 53 is applied to the lower clad 5a formed on the wafer substrate 51 with a predetermined film thickness using a photosensitive polymer material constituting the core 4. . As the polymer material constituting the core 4, a material having a slightly higher refractive index than the polymer material constituting the lower clad 5a is used.

  Next, as shown in FIG. 2 (c), a portion where the core 4 is formed by irradiating the core forming thin film 53 with ultraviolet rays through a mask 54 in which a pattern of a plurality of cores 4 is formed at a predetermined pitch. The core forming thin film 53 is cured. Then, as shown in FIG. 2D, the core 4 is formed on the lower clad 5a by removing the core-forming thin film 53 other than the portion where the core 4 is formed by solution development.

  Next, as shown in FIG. 2E, an upper clad forming thin film 52b is formed on the lower clad 5a and the core 4 fabricated on the wafer substrate 51 by a photosensitive polymer material constituting the upper clad 5b. Apply by film thickness. As the polymer material constituting the upper clad 5b, the same material as the polymer material constituting the lower clad 5a is used.

  Next, the upper clad formation thin film 52 b is cured by irradiating ultraviolet rays UV, and the upper clad 5 b is formed on the lower clad 5 a and the core 4.

  Thereby, as shown in FIG. 3, a waveguide sheet 2 </ b> A in which a plurality of cores 4 are formed at a predetermined pitch is manufactured on the wafer substrate 51.

  Next, as shown in FIG. 4, a plurality of support substrates 3 </ b> A are bonded and fixed to the surface of the waveguide sheet 2 </ b> A manufactured on the wafer substrate 51 and supported by the wafer substrate 51. The support substrate 3 </ b> A is fixed in a direction along the arrangement direction of the plurality of cores 4 with a predetermined interval along the extending direction of the cores 4.

  Here, in order to obtain a waveguide sheet 2A having a predetermined shape by dividing the waveguide sheet 2A produced on the wafer substrate 51 by dicing, the support substrate 3A located at the end of the waveguide sheet 2A. The arrangement of the support substrates 3A is set so that the cutting clearance 9 described with reference to FIG.

  Next, the waveguide sheet 2A is cut at a mirror cut position C1 indicated by a two-dot chain line in FIG. 5 and a division cut position C2 indicated by a one-dot chain line in FIG. The mirror cut position C1 is an example of an inclined end face formation position, and is set in a direction orthogonal to the extending direction of the core 4 and across the core 4 and at a non-attaching position of the support substrate 3A. The division cut position C <b> 2 is set in a direction crossing the support substrate 3 </ b> A along the extending direction of the core 4 and at a position where the core 4 is not formed.

  FIG. 6 is a cross-sectional view of the main part showing the dicing process, FIG. 6 (a) shows the dicing process at the mirror cut position C1, and FIG. 6 (b) shows the dicing process at the divided cut position C2.

  At the mirror cut position C1, as shown in FIG. 6A, the waveguide sheet 2A is cut by a mirror cut blade 61 having a blade portion having a V-shaped cross section. At the division cut position C2, as shown in FIG. 6B, the waveguide sheet 2A is cut by a dicing blade 62 having a vertical blade portion.

  As a result, at the mirror cut position C1, the end face of the waveguide sheet 2A is cut with an inclination of about 45 degrees across the core 4, and the inclined end face 6 having the reflecting surface 7 is formed.

  The reflecting surface 7 is required to have a predetermined surface roughness to reflect light, and a fine mirror cut blade as a dicing blade in order to obtain a highly accurate finished surface when forming the inclined end surface 6 by dicing. 61 is used.

  For this reason, at the mirror cut position C1, it is difficult to cut the support substrate 3A made of silicon or the like together with the waveguide sheet 2A. As a result, at the mirror cut position C1, the cutting relief 9 is formed so that the support substrate 3A is not disposed, and the space between the support substrates 3A can be cut.

  On the other hand, at the division cut position C2, the end face of the waveguide sheet 2A is cut at approximately 90 degrees to form the vertical end face 8, and the waveguide sheet 2A is divided. Since the vertical end face 8 is not required to have a finished surface, a dicing blade 62 capable of cutting a silicon substrate or the like can be used as the dicing blade. For this reason, the division cut position C2 is a position that crosses the support substrate 3A, and the waveguide substrate 2A and the support substrate 3A are cut together so that the support substrate 3A extends to the vertical end surface 8 of the waveguide sheet 2A. I try to get it.

  After the waveguide sheet 2A is cut into a predetermined size by the above dicing process, the waveguide sheet 2A is peeled from the wafer substrate 51 by wet chemical treatment or the like. Thereby, the optical waveguide 1A shown in FIG. 1 is manufactured.

  Here, internal stress is inherent in the waveguide sheet 2A during the manufacturing process due to a difference in linear expansion coefficient from the wafer substrate 51, thermal stress, and material shrinkage. Therefore, when the waveguide sheet 2A not provided with the support substrate 3A is a single structure, when the waveguide sheet 2A is peeled from the wafer substrate 51, the waveguide sheet 2A expands or contracts due to relaxation of internal stress, or warps. Occurs. As a result, the pitch of the core 4 of the manufactured waveguide sheet 2A is deviated from the prescribed mask pattern.

  Therefore, by predicting the deformation amount of the waveguide sheet 2A and correcting the mask pattern of the mask 54 described in the manufacturing process of FIG. 2, a prescribed pitch can be obtained in the deformed waveguide sheet 2A. Although a technique has been proposed, the deformation amount of the waveguide sheet 2A cannot be accurately predicted, and it is difficult to accurately form the pitch of the core 4.

  On the other hand, when the waveguide sheet 2A is peeled from the wafer substrate 51 by attaching the support substrate 3A to the surface of the waveguide sheet 2A before peeling the waveguide sheet 2A from the wafer substrate 51, The internal stress of the waveguide sheet 2A is received by the support substrate 3A, and the shape of the waveguide sheet 2A is maintained. Thereby, even after the waveguide sheet 2A is peeled from the wafer substrate 51, the waveguide sheet 2A does not expand or contract.

  In this example, since the support substrate 3A is attached to the waveguide sheet 2A in a direction extending along the alignment direction of the cores 4, in particular, the expansion or contraction of the waveguide sheet 2A along the alignment direction of the cores 4 Is suppressed, and the core 4 is kept at a pitch interval according to a prescribed mask pattern. This eliminates the need for mask pattern correction and achieves high pitch accuracy.

  Further, by attaching the support substrate 3A to both ends of the waveguide sheet 2A along the extending direction of the core 4, warpage at the end of the waveguide sheet 2A is also suppressed.

  The support substrate 3A may be substantially the same size as the waveguide sheet 2A. However, as in this example, the support substrate 3A is provided at both ends of the waveguide sheet 2A along the extending direction of the core 4, respectively. If the is attached, the expansion, contraction, warpage, and the like of the waveguide sheet 2A are suppressed, and the size of the support substrate 3A can be reduced, so that the cost can be reduced.

<Configuration Example of Optical Waveguide of Second Embodiment>
7A and 7B are configuration diagrams showing an example of the optical waveguide according to the second embodiment. FIG. 7A is a plan view, and FIG. 7B is a cross-sectional view taken along line BB in FIG.

  The optical waveguide 1B according to the second embodiment includes a waveguide sheet 2B having a core / cladding structure and a support substrate 3B that maintains the shape of the waveguide sheet 2B, and is a light guide that serves as a light incident / exit surface for the core 4. The waveguide end face is constituted by a vertical face.

  The waveguide sheet 2B is made of, for example, a polymer material, and is embedded type including one or a plurality of cores 4 extending linearly, and a lower clad 5a and an upper clad 5b constituting a clad layer 5 covering the core 4. It is a waveguide. In this example, the plurality of cores 4 are arranged in parallel at a predetermined pitch, and the thickness of the waveguide sheet 2B is about 100 μm.

  The waveguide sheet 2B has a quadrangular shape and faces the extending direction of the cores 4, and incident / exit vertical end faces 10 are formed on the two sides where each core 4 intersects. Vertical end surfaces 8 are formed on two sides substantially parallel to 4.

  The incoming / outgoing vertical end face 10 is a plane of approximately 90 degrees with respect to the face of the waveguide sheet 2B, and the end face of the core 4 is exposed to form the incoming / outgoing face 11. Thereby, the light incident on the waveguide sheet 2 </ b> B from the incident / exit surface 11 is coupled to the core 4, propagates through the core 4, and the light propagated through the core 4 is emitted from the incident / exit surface 11.

  The support substrate 3B is bonded and fixed to the surface of the waveguide sheet 2B. Like the support substrate 3A of the optical waveguide 1A of the first embodiment, the support substrate 3B is made of, for example, a single material of silicon (Si), glass, resin, or a mixed material thereof, and the shape of the waveguide sheet 2B It has a thickness that can hold.

  The support substrate 3B has, for example, the same length as the width of the waveguide sheet 2B along the alignment direction of the cores 4 so that the pitch between the cores 4 can be maintained, and extends in the alignment direction of the cores 4 Is attached to the waveguide sheet 2B.

  In this example, two support substrates 3B are attached to the waveguide sheet 2B, and the attachment positions of the support substrate 3B are set at both end portions in the length direction of the waveguide sheet 2B along the extending direction of the core 4. The The support substrate 3B and the incident / exit vertical end face 10 are formed on the same plane.

<Example of Manufacturing Process of Optical Waveguide of Second Embodiment>
FIG. 8 is a plan view showing the dicing process of the waveguide sheet 2B. Next, the manufacturing process of the optical waveguide 1B of the second embodiment will be described as an example of the second embodiment of the manufacturing method of the optical waveguide. To do.

  Here, the process of manufacturing the waveguide sheet 2B on the wafer substrate 51 is the same as the manufacturing process of the waveguide sheet 2A described with reference to FIG. 2, and the description thereof is omitted here.

  As shown in FIG. 8, a plurality of support substrates 3B are bonded and fixed to the surface of the waveguide sheet 2B that is fabricated on the wafer substrate 51 and supported by the wafer substrate 51 as shown in FIG. The support substrate 3 </ b> B is fixed at a predetermined interval along the extending direction of the cores 4 in the direction along the alignment direction of the plurality of cores 4.

  Next, the waveguide sheet 2B is cut at a first division cut position C3 indicated by a two-dot chain line in FIG. 8 and at a second division cut position C4 indicated by a one-dot chain line in FIG. The first division cut position C3 is set in a direction orthogonal to the extending direction of the core 4 and across the core 4 and at the mounting position of the support substrate 3B. The second divided cut position C4 is set in a direction crossing the support substrate 3B along the extending direction of the core 4 and at a position where the core 4 is not formed.

  FIG. 9 is a cross-sectional view of the main part showing the dicing process, FIG. 9A shows the dicing process at the first divided cut position C3, and FIG. 9B shows the dicing process at the second divided cut position C4. .

  The first divided cut position C3 and the second divided cut position C4 both cut the waveguide sheet 2B with a dicing blade 62 having a vertical blade portion.

  Thus, at the first division cut position C3, the end face of the waveguide sheet 2B is cut at approximately 90 degrees across the core 4 and the support substrate 3B, and the incident / exit vertical end face 10 having the entrance / exit face 11 is formed. The waveguide sheet 2B is divided.

  The entrance / exit surface 11 is a surface through which light enters or exits. However, if the light-transmitting substance is interposed and coupled to an optical transmission path such as an optical fiber, the accuracy of the finished surface is not required. Thereby, it is possible to use the dicing blade 62 that can cut a silicon substrate or the like as the dicing blade.

  For this reason, the first division cut position C3 is a position that crosses the support substrate 3B, and the waveguide sheet 2B and the support substrate 3B are cut together, so that the incident / exit vertical end face 10 of the waveguide sheet 2B is separated from the support substrate 3B. A form located on the same plane is obtained.

  Further, at the second division cut position C4, the end face of the waveguide sheet 2B is cut at approximately 90 degrees to form the vertical end face 8, and the waveguide sheet 2B is divided. Since the vertical end face 8 is not required to have a finished surface, a dicing blade 62 capable of cutting a silicon substrate or the like can be used as the dicing blade. For this reason, the support substrate 3B extends to the vertical end surface 8 of the waveguide sheet 2B by cutting the waveguide sheet 2B and the support substrate 3B together as a position where the second division cut position C4 crosses the support substrate 3B. The form which was made is obtained.

  After the waveguide sheet 2B is cut into a predetermined size by the above dicing process, the waveguide sheet 2B is peeled from the wafer substrate 51 by wet chemical treatment or the like. Thereby, the optical waveguide 1B shown in FIG. 7 is produced.

  Even in the optical waveguide 1B of the second embodiment, the support substrate 3B is attached to the surface of the waveguide sheet 2B before the waveguide sheet 2B is peeled from the wafer substrate 51, so that the waveguide sheet 2B is removed from the wafer substrate 51. Is peeled off, the shape of the waveguide sheet 2B is held by the support substrate 3B, and even after the waveguide sheet 2B is peeled from the wafer substrate 51, the waveguide sheet 2B does not expand or contract or warp.

  In particular, the end face of the waveguide sheet 2B intersecting the core 4 is configured as an incident / exit vertical end face 10 perpendicular to the plane of the waveguide sheet 2B, so that the input / output vertical end face 10 is on the same plane as the support substrate 3B. Since it can be set as the form which is located, the curvature etc. in the edge part of the waveguide sheet | seat 2B can be suppressed further.

<Configuration Example of Optical Module of First Embodiment>
FIG. 10 is a configuration diagram illustrating an example of the optical module according to the first embodiment. The optical module 21A of the first embodiment includes the optical waveguide 1A described in FIG. 1 and the like, the surface light emitting element 22 and the light receiving element 23 as optical elements coupled to the optical waveguide 1A, and the optical waveguide 1A and the surface type. A mounting substrate 24 on which the light emitting element 22 and the light receiving element 23 are mounted is provided.

  As described with reference to FIG. 1 and the like, the configuration of the optical waveguide 1A is such that the support substrate 3A is attached to the surface of the waveguide sheet 2A including the core 4 and the cladding layer 5, and the shape of the waveguide sheet 2A is maintained. . The waveguide sheet 2A has inclined end surfaces 6 having reflecting surfaces 7 at both ends, and a cutting relief portion 9 is formed between the inclined end surface 6 and the support substrate 3A.

  The mounting substrate 24 has the optical waveguide 1A mounted on the surface, mounting recesses 25a and 25b formed at mounting positions of the surface light emitting element 22 and the light receiving element 23, and a space is formed below the waveguide sheet 2A. Is done.

  The surface light emitting device (VCSEL) 22 is mounted on the mounting recess 25a of the mounting substrate 24 so as to face the reflecting surface 7 of the one inclined end surface 6 of the waveguide sheet 2A, and converts the input electric signal into an optical signal. Then exit.

  The light receiving element 23 is mounted on the mounting recess 25b of the mounting substrate 24 so as to face the reflecting surface 7 of the other inclined end face 6 of the waveguide sheet 2A, and converts the incident optical signal into an electrical signal and outputs it. . As shown in FIG. 1, when a plurality of cores 4 are arranged in parallel, a plurality of surface light emitting elements 22 and light receiving elements 23 corresponding to each core 4 are respectively adjusted to the pitch of the cores 4. Arranged in parallel.

  The manufacturing process of the optical module 21A having the above-described configuration will be described. After the surface light emitting element 22 and the light receiving element 23 are mounted on the mounting substrate 24, the optical waveguide 1A manufactured by the process described with reference to FIGS. Mounted on the substrate 24. That is, the support substrate 3A is bonded and fixed to the waveguide sheet 2A produced on the wafer substrate 51, and the waveguide sheet 2A divided by dicing is peeled from the wafer substrate 51 to produce the optical waveguide 1A. Then, the optical waveguide 1A in which the shape of the waveguide sheet 2A is held by the support substrate 3A is fixed to the mounting substrate 24 by adhesion or the like.

  Next, the operation of the optical module 21A will be described. When an electric signal is input to the surface light emitting element 22, the surface light emitting element 22 emits an optical signal. The optical signal emitted from the surface light emitting element 22 is emitted in a direction substantially perpendicular to the mounting substrate 24 and enters from the lower surface of the waveguide sheet 2A. The optical signal incident substantially perpendicularly from the lower surface of the waveguide sheet 2 </ b> A is reflected by one reflecting surface 7, coupled to the core 4, and propagated through the core 4.

  The optical signal propagated through the core 4 is reflected by the other reflecting surface 7 and is emitted substantially vertically from the lower surface of the waveguide sheet 2A. Then, the optical signal emitted substantially vertically from the lower surface of the waveguide sheet 2A enters the light receiving element 23, is converted into an electric signal by the light receiving element 23, and is output.

  As described above, the shape of the optical waveguide 1A constituting the optical module 21A is held by the support substrate 3A, thereby suppressing the occurrence of expansion, contraction, warpage, or the like of the waveguide sheet 2A during the manufacturing process or operation. Is done.

  If the pitch of the core 4 is changed in the manufacturing process of the optical waveguide 1A, the optical waveguide 1A is mounted on the mounting substrate 24 and the optical element is accurately aligned when coupled with the optical element. This is not possible and the coupling efficiency is reduced and the loss is increased.

  In the configuration in which the support substrate 3A is not provided, the pitch of the core 4 may expand and contract in units of 10 μm in the manufacturing process of the optical waveguide 1A. Since the pitch of the core 4 is set to, for example, 250 μm, the amount of change in the pitch of the core 4 when the support substrate 3A is not provided becomes a large value with respect to the pitch of the core 4.

On the other hand, since the shape of the waveguide sheet 2A is held by the support substrate 3A, a change in the pitch of the core 4 is suppressed, the alignment with the optical element can be performed accurately, and the coupling efficiency is improved. Loss can be reduced. In particular, by attaching the support substrate 3A in the vicinity of the end of the waveguide sheet 2A coupled to the optical element, it is possible to suppress the change in the pitch of the core 4 at the site coupled to the optical element, and to reduce the loss. Optical coupling characteristics can be realized.
Further, even when heat stress is applied to the waveguide sheet 2A during operation of the optical module 21A, the waveguide sheet 2A is held in shape by the support substrate 3A, so that the waveguide sheet 2A expands, contracts, warps, and the like. Generation is suppressed, and a decrease in coupling efficiency can be suppressed.

<Configuration Example of Optical Module of Second Embodiment>
FIG. 11 is a configuration diagram illustrating an example of an optical module according to the second embodiment. The optical module 21B of the second embodiment includes an optical waveguide 1C, a surface light emitting element 22 and an optical fiber 26 coupled to the optical waveguide 1C, and an optical waveguide 1C, the surface light emitting element 22 and the optical fiber 26. The mounting board 27 is provided.

  In the optical waveguide 1C, an inclined end surface 6 having a reflecting surface 7 is formed at one end of a waveguide sheet 2C having a core 4 and a cladding layer 5, and an incident / exiting vertical end surface 10 having an incident / exit surface 11 is formed at the other end. The The waveguide sheet 2 </ b> C has a cutting relief portion 9 on the surface on the inclined end surface 6 side, and a support substrate 3 </ b> A is attached. The surface on the incident / exit vertical end surface 10 side is flush with the incident / exit vertical end surface 10. A support substrate 3B is attached to hold the shape of the waveguide sheet 2C.

  The mounting substrate 27 has the optical waveguide 1C mounted on the surface thereof, a mounting recess 27a formed at the mounting position of the surface light emitting element 22, and a space formed below the waveguide sheet 2C.

  The surface light emitting element 22 is mounted on the mounting recess 27a of the mounting substrate 27 so as to face the reflecting surface 7 of the inclined end surface 6 of the waveguide sheet 2C, and converts the input electric signal into an optical signal and emits it.

  The optical fiber 26 is an example of an optical transmission path, and is supported by a fiber block 28 having a V-groove (not shown) and mounted on a substrate (not shown) together with a mounting board 27. The optical fiber 26 is mounted so as to face the incident / exit end face 10 of the waveguide sheet 2C. For example, the refractive index is equal to that of the core 4 between the incident / exit end face 10 of the waveguide sheet 2C and the end face of the optical fiber 26. The light-transmitting substance is intervened and bonded.

  Next, the operation of the optical module 21B will be described. When an electric signal is input to the surface light emitting element 22, the surface light emitting element 22 emits an optical signal. The optical signal emitted from the surface light emitting element 22 is emitted in a direction substantially perpendicular to the mounting substrate 27 and enters from the lower surface of the waveguide sheet 2C. The optical signal incident substantially perpendicularly from the lower surface of the waveguide sheet 2 </ b> C is reflected by the reflecting surface 7, coupled to the core 4, and propagated through the core 4. The optical signal propagated through the core 4 exits from the incident / exit surface 11 and enters the optical fiber 26, and propagates through the optical fiber 26.

  If the light receiving element 23 described in the optical module 21A of the first embodiment is mounted instead of the surface light emitting element 22, the optical signal propagated through the optical fiber 26 is cored from the incident / exit surface 11 4 and propagates through the core 4, the optical signal propagated through the core 4 is reflected by the reflecting surface 7, and is emitted substantially vertically from the lower surface of the waveguide sheet 2 </ b> C. The optical signal emitted substantially vertically from the lower surface of the waveguide sheet 2C enters the light receiving element 23, is converted into an electrical signal, and is output.

  Even in the optical waveguide 1C constituting the optical module 21B, the shape is held by the support substrates 3A and 3B, thereby suppressing the occurrence of expansion, contraction, warpage, and the like of the waveguide sheet 2C during the manufacturing process and operation. Thereby, alignment with the optical fiber 26 can be performed accurately, coupling efficiency can be improved, and loss can be reduced.

  The present invention is applied to an optical communication module between boards or chips of an electronic device, a connector of a communication cable using an optical fiber, and the like.

It is a block diagram which shows an example of the optical waveguide of 1st Embodiment. It is process drawing which shows the manufacturing process of a waveguide sheet. It is a top view which shows an example of the produced waveguide sheet. It is a top view which shows the sticking process of a support substrate. It is a top view which shows the dicing process of a waveguide sheet. It is principal part sectional drawing which shows a dicing process. It is a block diagram which shows an example of the optical waveguide of 2nd Embodiment. It is a top view which shows the dicing process of a waveguide sheet. It is principal part sectional drawing which shows a dicing process. It is a block diagram which shows an example of the optical module of 1st Embodiment. It is a block diagram which shows an example of the optical module of 2nd Embodiment.

Explanation of symbols

1A, 1B ... Optical waveguide, 2A, 2B ... Waveguide sheet, 3A, 3B ... Support substrate, 4 ... Core, 5 ... Cladding layer, 6 ... Inclined end face, 7. ··· Reflecting surface, 8 ··· vertical end surface, 9 ··· cutting relief portion, 10 ··· input / exit vertical end surface, 11 ··· I / O surface, 21A, 21B ··· optical module, 22 ··· Surface light emitting element, 23... Light receiving element, 26... Optical fiber, C1.

Claims (11)

A waveguide sheet having at least one core and a cladding;
An optical waveguide comprising: a support substrate that holds the shape of the waveguide sheet and is attached to a surface of the waveguide sheet. The optical waveguide according to claim 1, wherein the support substrate is attached at least to both ends of the waveguide sheet along a direction in which the core extends. The waveguide sheet has an inclined end surface formed at an end along the extending direction of the core, and a reflection surface is formed by the end surface of the core exposed at the inclined end surface.
The optical waveguide according to claim 1, further comprising a cutting relief portion that forms a gap between the support substrate and the inclined end surface. The optical waveguide according to claim 1, wherein the waveguide sheet has a vertical end surface formed at an end portion along a direction in which the core extends, and the vertical end surface is formed on the same plane as the support substrate. Waveguide. The optical waveguide according to claim 1, wherein the waveguide sheet is made of a polymer material. The optical waveguide according to claim 1, wherein the support substrate is made of silicon, glass, a resin material, or a mixed material containing these. An optical waveguide in which a support substrate for holding the shape of the waveguide sheet is attached to a surface of the waveguide sheet having at least one core and a clad;
An optical module comprising: an optical element optically coupled to the core and an optical transmission path, or both an optical element and an optical transmission path. The waveguide sheet has an inclined end surface formed at an end along the extending direction of the core, and a reflection surface is formed by the end surface of the core exposed at the inclined end surface.
The optical module according to claim 7, wherein a planar optical element is disposed as the optical element so as to face the reflecting surface. Forming a waveguide sheet having at least one core and clad on the wafer substrate;
A support substrate is attached to the surface of the waveguide sheet formed on the wafer substrate,
A method of manufacturing an optical waveguide, comprising: peeling off the waveguide sheet to which the support substrate is attached from the wafer substrate to produce an optical waveguide in which the shape of the waveguide sheet is held by the support substrate. An inclined end surface forming position is set in a direction across the core and at a non-attached position of the support substrate with respect to the waveguide sheet formed on the wafer substrate and attached with the support substrate. The formation position is cut with a blade having a blade portion corresponding to the angle of the inclined end surface formed on the waveguide sheet, and after forming the inclined end surface on the waveguide sheet, the waveguide sheet is peeled off from the wafer substrate. The method of manufacturing an optical waveguide according to claim 9. A vertical end face forming position is set on the waveguide sheet formed on the wafer substrate and attached to the support substrate in a direction transverse to the core and at the mounting position of the support substrate. After cutting the position with a blade having a blade portion corresponding to the angle of the vertical end surface formed on the waveguide sheet, and forming the vertical end surface on the same plane as the support substrate on the waveguide sheet, the waveguide The method for manufacturing an optical waveguide according to claim 9, wherein the sheet is peeled from the wafer substrate.

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