JP5907035B2 - Optical interconnect device manufacturing method and optical interconnect device - Google Patents

Description

  The present invention relates to an optical interconnect device manufacturing method and an optical interconnect device.

  In recent years, processing capabilities of supercomputers, high-end servers, routers, and the like have improved dramatically. A large capacity exceeding 1 Tbps is demanded as a transmission capacity of a backplane connecting between boards in the apparatus. For this reason, the introduction of optical interconnection is being considered in place of interconnection by electrical wiring, which has strict bandwidth restrictions.

  In particular, it is expected to use a polymer optical waveguide that can be highly integrated and reduced in weight for optical interconnection between boards within a relatively short transmission distance, such as in a rack or equipment.

  For the optical interconnection, a light emitting element such as a laser diode or a photodiode or a light receiving element is used. A surface light emitting type or surface light receiving type optical element is suitable for broadband optical interconnection because the light emitting direction and light receiving direction are perpendicular to the substrate and can be two-dimensionally arrayed.

  In FIG. 1, a surface optical device 140 is mounted face up or face down on a substrate 110 on which an optical waveguide 120 is formed. When optical coupling is realized between the planar optical element 140 and the optical waveguide 120, a beam emitted from the optical waveguide 120 in the horizontal direction is optically changed in the vertical direction, or emitted from the planar optical element 140 in the vertical direction. A technique for changing the optical path of a horizontal beam in the horizontal direction is used. One method is an inclined mirror 130 in which a metal film is formed on a 45-degree inclined surface.

  However, the beam emitted from the end face of the waveguide core 121 sandwiched between the clads 122 and 123 and the beam emitted from the planar optical element 140 are divergent beams having a divergence angle of about 10 to 30 degrees. The beam diameter expands approximately in proportion to the distance when it enters the planar optical element 140 through 90-degree optical path conversion from the waveguide core 121 or vice versa. Therefore, it is difficult to optically couple the surface optical element 140 and the waveguide core 121 with high efficiency by the inclined mirror 130.

  Although it is possible to reduce the beam diameter by inserting a lens in the beam propagation path, the increase in the number of parts increases the cost and hinders downsizing of the device.

  There has been proposed a method of condensing a beam by making the reflecting surface of an inclined mirror into an elliptical concave surface (see, for example, Patent Document 1). First, an inclined surface is formed on a silicon substrate by anisotropic etching using potassium hydroxide as an etchant. Thereafter, an opening is provided in a part of the inclined surface with a photoresist, and an elliptical concave portion is formed on the inclined surface by isotropic etching using a mixed solution of hydrofluoric acid, nitric acid and acetic acid. A condensing mirror is produced by evaporating Al in the recess.

  In this method, the ellipsoid formed by etching has a major axis of 50 μm and a minor axis of 25 μm. Therefore, the waveguide core can be applied to an optical waveguide having a cross-sectional dimension of about 10 μm × 10 μm. In a multimode optical waveguide that is normally applied in an optical interconnection within a board or between boards, the core cross-sectional dimension is several tens of μm × several tens of μm. In this case, it is necessary to form a larger elliptical spherical recess. However, the photoresist formed on the inclined surface cannot withstand long-time etching and cannot form a uniform elliptical sphere, making it difficult to produce a large-diameter condensing mirror.

JP 2001-141965 A JP 9-40870

  It is an object of the present invention to provide a method of manufacturing an optical interconnect device capable of appropriately performing optical path conversion or optical coupling according to the core cross-sectional dimension of an optical waveguide.

In order to solve the above-mentioned problems, a method for manufacturing an optical interconnect device is as follows:
A spot facing portion is formed at a predetermined position of the resin layer formed on the substrate,
In a state where the substrate is inclined in the first direction, a foamable resin is disposed in the spot facing portion,
While maintaining the inclination of the substrate, foaming and curing the foamable resin in a reduced pressure atmosphere,
Returning to normal pressure after the foaming and curing, the surface of the foamable resin in contact with the atmosphere is deformed into a concave surface,
Forming a reflective film on the concave surface;
A reflective film is formed on the concave surface to form a micromirror having a concave reflective surface inclined with respect to the substrate.

  An optical interconnect device capable of appropriately performing optical path conversion or optical coupling according to the core cross-sectional dimension of the optical waveguide can be manufactured.

It is a figure explaining the optical path conversion using an inclination mirror. It is a schematic sectional drawing of the micromirror of embodiment. It is a manufacturing-process figure of the micromirror of embodiment. It is a manufacturing-process figure of the micromirror of embodiment. It is a manufacturing-process figure of the micromirror of embodiment. It is a manufacturing-process figure of the micromirror of embodiment. It is a manufacturing-process figure of the micromirror of embodiment. It is a figure explaining the process of FIG. It is a figure which shows an example of the optical interconnect device using the micromirror of embodiment. It is a figure which shows an example of the optical interconnection to which the micro mirror (optical coupling mirror) of embodiment is applied.

  Hereinafter, embodiments of the invention will be described with reference to the drawings.

  FIG. 2 is a schematic configuration diagram of the optical interconnect device 10 using the micromirror 30 of the embodiment. The optical interconnect device 10 includes an optical waveguide 20 formed on the substrate 11 and a micromirror 30 that condenses light by converting the direction of a beam propagating through the optical waveguide 20 by 90 degrees.

  The micromirror 30 is disposed in a spot facing portion 25 provided in the optical waveguide layer 26 in which the optical waveguide 20 is formed. The optical waveguide 20 includes a waveguide core 21 sandwiched between a lower clad 22 and an upper clad 23. The micro mirror 30 includes an inclined body 31 having a concave surface 31 a inclined with respect to the light propagation direction of the optical waveguide 20, and a reflective film 32 formed on the concave surface 31 a of the inclined body 31. The inclined body 31 is made of a foamable resin that foams and cures under reduced pressure.

  As will be described later, the concave surface 31a of the inclined body 31 has a uniform concave curved surface because it is formed by using foaming hardening of the foamable resin under reduced pressure and returning to normal pressure. By forming the spot facing portion 25 corresponding to the cross-sectional dimension of the waveguide core 21 and the beam divergence angle, an accurate concave surface 31 a can be formed on the surface of the inclined body 31. Therefore, the micromirror 30 suitable for both the multimode core and the single mode core can be manufactured.

  In the example of FIG. 2, the micromirror 30 converts the beam propagating through the waveguide core 21 and exiting in the direction horizontal to the substrate 11 by 90 degrees and condensing it in the vertical direction. Optical path conversion or optical coupling is also possible. In other words, the direction of a beam emitted from an optical element (not shown) in a direction perpendicular to the substrate 11 can be changed by 90 degrees to function as an optical path conversion mirror for focusing on the waveguide core 21.

  3 to 8 show manufacturing process examples of the micromirror 30 shown in FIG. 3A is a top view, and FIG. 3B is a cross-sectional view taken along the line AA ′ of FIG.

  In the process of FIG. 3, the resin layer 26 is formed on the substrate 11, and the spot facing portion 25 for forming the micromirror 30 is formed at a predetermined position of the resin layer 26. The substrate 11 is an arbitrary substrate such as a glass substrate, a resin substrate, or a semiconductor substrate. In the embodiment, since anisotropic dry etching is not used for forming the micromirror 30 itself, the substrate 11 is not limited to a silicon substrate, and any substrate can be used.

  In this example, the resin layer 26 is the optical waveguide layer 26 in which the optical waveguide 20 is formed. An embedded optical waveguide 20 having a lower cladding 22, a waveguide core 21, and an upper cladding 23 is formed on the substrate 11 by a photo process or the like. A portion of the optical waveguide layer 26 where the waveguide core 21 is formed is an optical waveguide circuit. The lower clad 22, the waveguide core 21, and the upper clad 23 are made of, for example, a polymer-based waveguide film. The cross-sectional dimension of the optical waveguide core 21 may be a multimode size or a single mode size.

  A spot facing portion 25 is formed at a predetermined position of the optical waveguide layer 26 to expose the cross section of the waveguide core 21. The spot facing portion 25 is formed using an appropriate tool such as a spot facing cutter, an end mill, and a carbon dioxide laser. The dimension of the spot facing portion 25 is appropriately set according to the cross-sectional size of the waveguide core 21 and the divergence angle of the beam emitted from the waveguide core 21.

  Next, in the step of FIG. 4, the foamable resin 51 is supplied to the spot facing portion 25 in a state where the substrate 11 is inclined 45 degrees. In this example, the stage (not shown) that holds the substrate 11 is tilted so that the exposed cross section of the waveguide core 21 is at a high position. Using an inkjet coating machine (not shown), a photocurable foaming resin 51 having a capacity necessary for forming the micromirror 30 is dropped from the coating head 54 into the spot facing portion 25.

  As the photocurable foamable resin 51, for example, a photocurable foamable siloxane composition is used. The photocurable foamable siloxane composition is a foamable siloxane that foams and cures rapidly at room temperature when irradiated with ultraviolet rays on a resinous monomer, and can be made into one component. For example, there is a mixture containing at least an organohydroxypolysiloxane, an organohydrogenpolysiloxane, and a photoactive platinum complex catalyst (see Patent Document 2).

  As the foamable resin 51, any material can be used as long as the material can be foamed and cured under reduced pressure. Therefore, a material obtained by adding a known foaming agent such as a compound having an azide group or a diazo group to a photocurable resin may be used. Further, a thermosetting foamable resin may be used.

  Next, in the process of FIG. 5, the substrate 11 on which the photocurable foamable resin 51 is applied to the spot facing portion 25 is accommodated in the decompression container 41 while being inclined by 45 degrees. The decompression vessel 41 is provided with an air release valve 42. The inside of the decompression container 41 is decompressed, and the photocurable foamable resin 51 is foamed and cured by irradiating the photocurable foamable resin 51 with ultraviolet rays L from the light irradiation head 55. Under the irradiation of ultraviolet rays, the photocurable foamable resin 51 expands while generating fine bubbles, and gradually hardens and foams and hardens while strengthening the adhesion with the bottom surface 25a and side surface 25b of the spot facing portion 25. Resin 53 is formed.

  Next, in the process of FIG. 6, the inclined body 31 having the concave surface 31 a is formed from the foam cured resin 53. FIG. 6C is a cross-sectional view taken along the line BB ′ of FIG. Specifically, in the state where the curing of the foam curable resin 53 is almost completed, the atmosphere release valve 42 of the decompression container 41 is opened, and the interior of the decompression container 41 is opened to the atmosphere. Since the bubbles generated in the foam curable resin 53 have a lower atmospheric pressure than the atmospheric pressure, the foam curable resin 53 contracts. At this time, the surface of the foamed cured resin 53 that is not in contact with the atmosphere is intimately cured with respect to the bottom surface 25 a and the side surface 25 b of the spot facing portion 25 and the exposed end surface of the optical waveguide 20. The surface is recessed and a concave surface (curved surface) 31a is formed.

  Next, a reflective film 32 is formed on the concave surface 31a of the inclined body 31 in the step of FIG.

  FIG. 8 is a diagram for further explaining the process of the reflective film 32 of FIG. First, as shown in FIG. 8A, after forming the concave surface 31a on the inclined body 31, a dry film resist 61 is laminated on the surface of the optical waveguide layer 26 on the substrate 11, and patterned by exposure and development. An opening 61 a is formed in a region corresponding to the spot facing portion 25.

  Next, as shown in FIG. 8B, a metal film 62 is formed on the entire surface by electroless plating and electrolytic plating. Thereby, the metal film 62 is also formed on the concave surface 31 of the inclined body 31 and the exposed surface of the optical waveguide 20.

  Next, as shown in FIG. 8C, the substrate 11 is inclined 45 degrees in the direction opposite to the dripping of the photocurable foamable resin 51, and the blast particles are irradiated from the nozzle head 63 of the sand blasting apparatus. The metal film 62 on the exposed surface of the optical waveguide 20 is removed while leaving the metal film 62 on the concave surface 31a. Since the blast particles emitted from the nozzle head 63 of the sand blasting device have high straightness, the metal film 62 on the exposed surface of the optical waveguide 20 can be removed without substantially affecting the metal film 62 on the concave surface 31a. .

  Next, as shown in FIG. 8D, after the metal film 62 on the exposed surface of the optical waveguide 20 is removed, the dry film resist 61 is removed using a peeling solution. Thereby, the micromirror 30 having the reflective film 32 on the concave surface 31a inclined with respect to the optical waveguide 20 is completed.

  According to this method, even when the cross-sectional dimension of the waveguide core 21 of the optical waveguide 20 is large, the micromirror 30 that realizes good optical coupling between the optical waveguide 20 and the planar optical element mounted on the substrate 11. Is produced.

  FIG. 9 is a schematic diagram of optical interconnect devices 70A and 70B in which the planar optical element 71 or 73 is mounted on the substrate 11 on which the optical waveguide 20 and the micromirror 30 are formed.

  In FIG. 9A, a surface emitting element 71 such as a surface emitting laser is bonded onto the substrate 11 with a conductive adhesive or solder. The reflective surface of the micromirror 30 (the reflective film 32 formed on the concave surface 31 a) is inclined with respect to the light emitting surface 72 of the surface light emitting element 71 and the end surface of the waveguide core 21 of the optical waveguide 20. The beam emitted from the light emitting surface 72 of the surface light emitting element 71 diverges at a constant angle, but is condensed by the micromirror 30 onto the incident surface of the waveguide core.

  In FIG. 9B, a surface light receiving element 73 such as a photodiode array is bonded onto the substrate 11 with a conductive adhesive or solder. The reflective surface of the micromirror 30 (the reflective film 32 formed on the concave surface 31 a) is inclined with respect to the light receiving surface 74 of the surface light receiving element 73 and the end surface of the waveguide core 21 of the optical waveguide 20. The beam emitted from the end face of the waveguide core 21 of the optical waveguide 20 diverges at a constant angle, but is condensed on the light receiving surface 74 of the surface light receiving element 73 by the micromirror 30.

  In the optical interconnect devices 70A and 70B shown in FIGS. 9A and 9B, the micromirror 30 having the concave surface 31a corresponding to the cross-sectional dimension of the waveguide core 21 is formed. Can be made.

  FIG. 10 shows an example of an electronic device (server rack, network rack, etc.) 1 to which the optical interconnect device of the embodiment is applied. A plurality of boards 3 are inserted into the backplane 2. On each board 3, nodes 5 are interconnected by optical wiring 4. The node 5 is an optoelectronic module in which, for example, the optical elements 71 and 73 shown in FIGS. 9A and 9B are mounted together with an electronic device such as an LSI chip and a memory. The optical interconnect device of the embodiment can be applied not only to the optical interconnect in each node 5 but also to the optical interconnect between the nodes 5.

  Hitachi Chemical's film-type optical waveguide material is used on the surface of Hitachi Chemical's glass epoxy printed board (model name: MCL-E-75G) with a thickness of 1.6 mm. The optical waveguide layer 26 is formed by forming the core 21 with a thickness of 50 μm and the upper cladding 23 with a thickness of 100 μm. The waveguide core 21 is a rectangular core, and the core film is processed into a waveguide having a width of 50 μm and a height of 50 μm by a general photolithography method. An upper clad 23 is laminated on the lower clad 22 and the waveguide core 21 to form an optical waveguide layer 26 having an embedded optical waveguide 20 (see FIG. 3).

  A counterbore 25 having a width of 200 μm, a length of 250 μm, and a depth from the upper surface of the upper cladding 23 of 250 μm is formed in the optical waveguide layer 26 (see FIG. 3).

  With the substrate 11 inclined at 45 degrees, 100 parts by weight of α, ω-dihydroxypolysiloxane having a viscosity of 3500 centistokes at 25 ° C. and α, ω-methyl hydrogen having a viscosity of 2 to 5 centistokes at 25 ° C. 5.0 nL of a photocurable foamable resin 51 in which 5 parts by weight of polysiloxane and 0.05 parts by weight of acetylacetonate platinum catalyst are mixed is dropped into the spot facing part 25 using a commercially available inkjet coating machine (FIG. 4). reference).

With the substrate 11 tilted, the substrate 11 is accommodated in the decompression container 41 and the interior of the container is decompressed until 5 Torr. Ultraviolet rays are irradiated for 90 seconds from a 100 mW / cm ² , 365 nm ultraviolet irradiation head 55 provided in the decompression vessel 41 to foam and cure the photocurable foamable resin 51. The photocurable foamable resin 51 expands to rise up the bottom surface 25a and the side surface 25b of the inclined spot facing portion 25 while generating bubbles. At that time, the expansion ratio is about 2 times, and the volume of the expanded foamed resin 53 after expansion is about 10 nL. In this state, the pressure of the gas in the generated bubbles is equal to the pressure in the decompression container 41 (see FIG. 5).

  Next, the air release valve 42 of the decompression container 41 is opened, and the atmospheric pressure in the decompression container 41 is returned to atmospheric pressure. Bubbles generated inside the foam curable resin 53 are pushed back to the atmospheric pressure and contracted, and the volume of the entire foam curable resin 53 is reduced to 5.5 nL. Since the foam cured resin 53 is constrained by the bottom surface 25a and the side surface 25b of the spot facing portion 25, the surface that comes into contact with the atmosphere changes to the concave surface 31a due to volume shrinkage. The radius of curvature of the surface is about 250 μm (see FIG. 5).

  Next, the reflective film 32 is formed on the concave surface 31a (see FIG. 7). First, a plating resist 61 (manufactured by Hitachi Chemical Co., Ltd .: RY-3625) is laminated on the upper surface of the optical waveguide layer 26, and an opening 61a is provided at a position corresponding to the spot facing portion 25 by exposure and development (FIG. 8A). reference).

  Next, 0.1 μm of Cu is formed by an electroless plating method, and 1.0 μm of Ni and 0.1 μm of Au are formed by an electrolytic plating method to form a Cu / Ni / Au film 62 (FIG. 8B). reference).

  Thereafter, the substrate 11 is inclined 45 degrees in the opposite direction to the time when the photocurable foaming resin 51 is dropped, and blasted using a sand blasting device (manufactured by Elfo-tec). Thereby, the Cu / Ni / Au film 62 on the exposed surface of the optical waveguide 20 is removed while leaving the Cu / Ni / Au film 62 on the concave surface 31a. As described above, since the blast particles 64 emitted from the nozzle head 63 of the sand blasting device have high straightness, the Cu / Ni / Au film 62 plated on the concave surface 31a is hardly affected. Further, the optical waveguide 20 is formed of a resin film, and its elastic modulus is about 100 times smaller than that of the ceramic blast particle 64, so that the end face is hardly damaged even after blasting (see FIG. 8C). ).

  Thereafter, the plating resist 61 is peeled off (see FIG. 8D). The Cu / Ni / Au film 62 remaining on the surface of the plating resist 61 is also removed. Thereby, the micromirror 30 is completed.

  In this state, when a laser beam having a wavelength of 850 nm is made incident from the other end face of the optical waveguide 20, the beam is reflected by the micromirror 30 and is optically changed in the vertical direction, and has a height of about 100 μm from the upper surface of the upper clad 23. Concentrate on the light. It was confirmed that the beam diameter of the focused beam was about 50 μm.

  The present invention is not limited to the above embodiments. The reflective film 32 formed on the concave surface 331a of the micromirror 30 is not limited to a Cu / Ni / Au film, but Al, Ni, Ti, Cu, Cr, Sn, Ag, Au, Pt, Ru, Pd, Rh, Os. , Ir, or an alloy thereof can be a single-layer or multilayer metal film.

  The formation of the reflective film 32 on the concave surface 31a of the micromirror 30 is not limited to the plating method, and any method such as a vacuum deposition method, a sputtering method, a laser ablation method, an aerosol deposition method, or the like can be used.

  When a thermosetting foamable resin is used as the foamable resin constituting the inclined body 31 of the micromirror 30, for example, a material obtained by adding a heating foaming agent to the thermosetting resin is used. In the decompression vessel 41, the foamable resin 51 is heated and foamed and cured by a halogen lamp (not shown) or the like. When heating is stopped in a state where foaming and curing have progressed and the atmosphere is released, bubbles of the foam cured resin 53 contract, and a uniform concave surface is formed on the surface in contact with the atmosphere.

  In the embodiment, the spot facing portion 25 is formed after the optical waveguide layer 26 having the optical waveguide 20 made of a resin material on the substrate 11, and the micromirror 30 is formed in the spot facing portion 25. It is not limited to.

  For example, an arbitrary resin layer is formed on the substrate 11, the spot facing portion 25 is formed at a predetermined portion of the resin layer, and the micromirror 30 is formed inside the spot facing portion 25 by the method described above. Thereafter, part or all of the resin layer may be removed, and the optical waveguide 20 may be formed so as to be optically coupled to the reflective surface 42 of the micromirror 30. In this case, the metal film 62 can be left only on the concave surface 31a of the micromirror 30 without using the sandblasting method, and the other metal film 62 can be peeled off and removed.

  The optical interconnect device of the embodiment can be used not only for high-speed optical transmission of servers and high-end computer systems, but also for any optical transmission system such as industrial use and public use. Further, it can be used for optical equipment, medical equipment, and information equipment that require optical path conversion.

The following notes are presented for the above explanation.
(Appendix 1)
A spot facing portion is formed at a predetermined portion of the resin layer (26) formed on the substrate,
In a state where the substrate is inclined in the first direction, a foamable resin is disposed in the spot facing portion,
While maintaining the inclination of the substrate, foaming and curing the foamable resin in a reduced pressure atmosphere,
Returning to normal pressure after the foaming and curing, the surface of the foamable resin in contact with the atmosphere is deformed into a concave surface,
Forming a reflective film on the concave surface;
A method of manufacturing an optical interconnect device, comprising: forming a reflective film on the concave surface to form a micromirror having a concave reflective surface inclined with respect to the substrate.
(Appendix 2)
The resin layer is an optical waveguide layer including an optical waveguide,
2. The method of manufacturing an optical interconnect device according to claim 1, wherein the spot facing portion is formed in the optical waveguide layer so that an end face of the waveguide core of the optical waveguide is exposed.
(Appendix 3)
The optical interconnect device manufacturing method according to appendix 2, wherein the first direction in which the substrate is inclined is an inclined direction in which the exposed end face of the waveguide core is located at a high position in the spot facing portion. Method.
(Appendix 4)
The reflective film is formed by forming a metal film on the entire surface of the substrate after forming the concave surface,
Inclining the substrate in a second direction opposite to the first direction, and removing the metal film formed on the exposed surface of the waveguide core by a sandblast method;
The method for manufacturing an optical interconnect device according to appendix 3, wherein:
(Appendix 5)
As the foamable resin, photocurable foamable resin is used,
The method for producing an optical interconnect device according to any one of appendices 1 to 4, wherein the photocurable foamable resin is foamed and cured by irradiating ultraviolet rays in the reduced-pressure atmosphere.
(Appendix 6)
As the foamable resin, a thermosetting foamable resin is used,
The method for manufacturing an optical interconnect device according to any one of appendices 1 to 4, wherein the thermosetting foamable resin is foamed and cured by heating in the reduced-pressure atmosphere.
(Appendix 7)
7. The method of manufacturing an optical interconnect device according to any one of appendices 1 to 6, wherein the foamable resin is dropped into the spot facing portion by an ink jet method.
(Appendix 8)
After placing the foamable resin in the spot facing portion, placing the substrate in a vacuum container while maintaining the inclination of the substrate,
After the foaming and curing under the reduced pressure atmosphere, the reduced pressure container is released to the atmosphere.
The method for manufacturing an optical interconnect device according to any one of appendices 1 to 7, wherein:
(Appendix 9)
A resin layer on the substrate;
Spot facings formed in the resin layer;
A micromirror disposed in the spot facing portion;
An optical waveguide optically coupled to the micromirror;
The micromirror includes:
An inclined body composed of a foamable curable resin that foams under reduced pressure and having a concave surface that is inclined with respect to the end face of the waveguide core of the optical waveguide;
A reflective film formed on the concave surface;
An optical interconnect device comprising:
(Appendix 10)
The optical interconnect device according to appendix 9, wherein the optical waveguide is a multimode optical waveguide.
(Appendix 11)
A planar optical element optically coupled to the micromirror;
Further comprising
11. The optical interconnect device according to appendix 9 or 10, wherein the micromirror converts a direction of input / output light of the planar optical element and a direction of input / output light of the optical waveguide by 90 degrees.

10, 70A, 70B Optical interconnect device 11 Substrate 20 Optical waveguide 21 Waveguide core 22, 23 Clad 25 Spot facing portion 26 Optical waveguide layer (resin layer)
30 Micromirror 31 Inclined body 31a Concave surface 32 Reflective film 53 Foam cured resin 71, 73 Planar optical element

Claims (6)

A spot facing portion is formed at a predetermined position of the resin layer formed on the substrate,
In a state where the substrate is inclined in the first direction, a foamable resin is disposed in the spot facing portion,
While maintaining the inclination of the substrate, foaming and curing the foamable resin in a reduced pressure atmosphere,
Returning to normal pressure after the foaming and curing, the surface of the foamable resin in contact with the atmosphere is deformed into a concave surface,
A method of manufacturing an optical interconnect device, comprising: forming a reflective film on the concave surface to form a micromirror having a concave reflective surface inclined with respect to the substrate. The resin layer is an optical waveguide layer including an optical waveguide,
The method of manufacturing an optical interconnect device according to claim 1, wherein the spot facing portion is formed in the optical waveguide layer so that an end face of a waveguide core of the optical waveguide is exposed.   3. The optical interconnect device according to claim 2, wherein the first direction in which the substrate is inclined is an inclination direction in which the exposed end surface of the waveguide core is located at a high position in the spot facing portion. Production method. The reflective film is formed by forming a metal film on the entire surface of the substrate after forming the concave surface,
Inclining the substrate in a second direction opposite to the first direction, and removing the metal film formed on the exposed surface of the waveguide core by a sandblast method;
The method of manufacturing an optical interconnect device according to claim 3, comprising: A resin layer on the substrate;
Spot facings formed in the resin layer;
A micromirror disposed in the spot facing portion;
An optical waveguide optically coupled to the micromirror;
The micromirror includes:
An inclined body composed of a foamable curable resin that foams under reduced pressure and having a concave surface that is inclined with respect to the end face of the waveguide core of the optical waveguide;
A reflective film formed on the concave surface;
An optical interconnect device comprising:   The optical interconnect device according to claim 5, wherein the optical waveguide is a multimode optical waveguide.

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